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UNITED STATES DEPARTMENT OF THE INTERIOR

Walter J. Hickel, Secretary

Russell E. Train, Under Secretary

Leslie L. Glasgow, Assistant Secretary

for Fish and Wildlife, Parks, and Marine Resources

Charles H. Meacham, Commissioner, U.S. FISH AND WILDLIFE SERVICE

Philip M. Roedel, Director, BUREAU OF COMMERCIAL FISHERIES

FISHERY BULLETIN

OF THE

FISH AND WILDLIFE SERVICE

VOLUME 65

<Hlt***

ISSUED 1965 AND 1966

UNITED STATES GOVERNMENT PRINTING OFFICE

WASHINGTON, D.C.

CONTENTS OF VOLUME 65

Number 1 (Issued October 1965)

Pago
Marine Decapod Crustaceans of the Carolina*. By Austin B. Williams I 298

Number 2 (Issued June 2, 1966)

Annual marks on shell and ligament of sea scallop Placopetten magellanicus. \i\ Arthur S. Merrill, Julius

A. Posgay, and Fred E. Nichy - 299-31 1

Dynamics of a Penaeid shrimp population and management implications. By Joseph H. Kutkuhn.. 313 338

Study of loss and delay of salmon passing Rock Island Dam, Columbia Hiver, 1954-56. By Robert R.

French and Roy J. Wahle 339 368

Occurrence in Tampa Bay Florida, of immature species dominant in Gulf of Mexico commercial

fisheries. By James E. Sykes and John H. Finucane - 369-379

Gill net mesh selection curves for Pacific salmon on the high seas. By Alvin E. Peterson... 381-390

Life history of the gizzard shad, Dorosoma cepedianum (Le Sueur), in western Lake EalE. By Anthony

Bodola - 391-425

BlOACCUMULATION OF RADIOACTIVE GOLD USED AS A SEDIMENT TRACER IN THE ESTUARINE ENVIRONMENT. By

Thomas W. Duke, John P. Baptist, and Donald E. Hoss 427 436

A Generic key to the protozoean, mysis, and post larval stages of the littoral Penaeidae of the north

western Gulf of Mexico. By Harry L. Cook__~: - 437-447

Migrations and geographic distribution of pink shrimp, Penaeus duroarum, of the Tortugas and Sanibel

Grounds, Florida. By T. J. Costello and Donald M. Allen - 449-459

Time of migration and age group structure of sockeye salmon (Oncorhynchus nerka) spawning popula-
tions in the Naknek River system, Alaska. By Richard R. Straty — 461-478

Skipjack tuna spawning in the Marquesas Islands and Tuamotu Archipelago. By Howard O. Yoshida_- 479-488

Food of y-oung-of-the-year walleyes in Lake Erie. By David R. Wolfert 489-494

Effect of the spawning bed environment on reproduction of pink and chum salmon. By William J.

McNeil - 495-525

Number 3 (Issued October 1966)

Life history of the spiny" dogfish. By Albert C.Jensen - 527-554

Pygmy whitefish Prosopium coulteri in the Naknek River system. By William R. Heard and Wilbur L.

Hartman 555-579

A review of western Atlantic cat sharks, Sciiliorhinidae, with descriptions of a new genus and five

new species. By Stewart Springer 581-624

Survey of pelagic fishes of the California current area. By Frederick H. Berry and Herbert C. Perkins. 625-682
*" Comparison of two methods of N-ethylcarbazole carbohydrate analysis. By Kenneth T. Marvin and

Raphael R. Proctor; Jr 683-684

Rapid Method for determining water content in oyster tissue. By Thomas C. Carver; Jr - 685-686

As the Nation's principal conservation agency, the Department of the
Interior has basic responsibilities for water, fish, wildlife, mineral, land, park, .
and recreational resources. Indian and Territorial affairs are other major
concerns of America's "Department of Natural Resources."

The Department works to assure the wisest choice in managing all our
resources so each will make its full contribution to a better United States —
now and in the future.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

By Austin B. Williams

University of North Carolina Institute of Fisheries Research,
Morehead City, North Carolina

INTRODUCTION

Knowledge of the crustacean fauna of the Caro-
linas has grown slowly over many decades. Early
in the last, century, Thomas Say described species
from the Carolinas, and in the middle 1800's Pro-
fessor L. R. Gibbes, who maintained a private
collection in Charleston, S.C., described species
from the Carolinas. William Stimpson (1860b),
who visited Beaufort, N.C., in company with T. N.
Gill, gave a list of 38 species of decapod crus-
taceans which he collected there. Elliott Cones
(1871), at that time an Army surgeon stationed
at Fort Macon, N.C., recorded 27 species of deca-
pods from the Beaufort area, 8 of which were
additions to Stimpson's list. Seven years later,
Coues and Yarrow (1878) gave a list of six
species, two of which had not appeared previously.
An appendix to the same paper by J. S. Kingsley
included 51 species from the Beaufort area, and
3 of these were additions to the fauna. A year
later, Kingsley (1870) contributed eight more new
records.

The collection which was the subject of Kings-
ley's report had been made by Professor H. E.
Webster, of Union College. It was later trans-
ferred, in part at least, to the U.S. National
Museum, and supplied the types of Lepldopa
■websteri Benedict and Pinnixa cristata Rathbun,
both collected near Beaufort, N.C.

Professor W. K. Brooks and his students, of the
Johns Hopkins University, studied crustaceans
at Beaufort at intervals from 1880 to 1903. They

Note. — Approved for publication May 25. 1964.

contributed information on habits and develop-
ment, but only one or two new species were added
to the faunal list.

Shore's manuscript included 87 species, but he
omitted 8 which had been listed by the writers
already mentioned. He had added 33 species,
making a total of 95 species for the region.

Following this, exploratory work on offshore
fishing banks by the Fish Hawk in the summers
of 1914 and 1915, energetic shore and shallow-
water collecting by parties from the Bureau of
Fisheries laboratory at Beaufort, and inclusion of
freshwater species from the region, enabled Hay
to add 57 species to Shore's list. These, plus de-
scription of a new species by Rathbun, brought
the total number known from Beaufort, N.C, in
1918 to 153 species.

The authors pointed out that some of these
species had not yet been reported from the area,
though from distribution elsewhere they might
be expected. Also, some of the species were con-
sidered more properly to be deep-sea forms, rather
than strictly members of the Beaufort fauna,
although they had been found on the continental
shelf not far distant.

In the year the handbook appeared, Mary J.
Rathbun brought out the first in a series of four
monographs on recent crabs of the Western Hemi-
sphere, and, thus, began a new advance in knowl-
edge of Carolinian crustaceans, later furthered
by major revisions of the Penaeidae by Burken-
road, revisions of Hippolytidae, Palaemonidae
and Scyllaridae by Holthuis, Galatheidae by

FISHERY BULLETIN : VOLUME 65. NO. 1

Chace, Paguridae by Wass, Thalassinidea by de
Man, Oxyrhyncha by Garth, and the Porcel-
lanidae by Haig. Schmitt's treatment, of the
Macrura and Anomura of the Puerto Rican area,
as well as his contributions on the Hippidae and
the. genera Callianassa and Upogebia, and Ver-
rill's completion of the work on Bernmdan deca-
pods added breadth to knowledge of distribution
as well as taxonomic stability. Closer at hand,
the studies of Lunz in South Carolina yielded
similar results. To this list of scholars could be
added the names of Borradaile, Glassell, and Pro-
venzano, who described new forms from the Caro-
linian province. The works of these and other
authors are given in detail in the text to follow.

Apart from these primarily systematic studies,
a growing number of ecological studies have been
published during the past 45 years. Such results
are not usually cited in systematic handbooks, but
because this one is directed primarily to students
and ecologists who are often newcomers to the
area, brief summaries have been attempted. The
review of literature, though not complete, is ex-
haustive enough to lead to most of the published
material.

Actually, few species have been studied in
detail. Of these, almost all are littoral species
easily accessible to the investigator by virtue of
their abundant numbers and ecological niches.
Beyond this, a few species of commercial value
such as Callinectes sajndus and Penaeus spp. have
been studied in detail. It is fair to say that
ecological studies are scarcely started.

SYSTEMATIC DISCUSSION

This is a review of published material. Ar-
rangement of families and genera follows that
adopted by the most recent reviser of each group.
Important diagnostic characters of families and
genera have been incorporated in keys and are
often repeated, in part, in species descriptions.
Brief diagnoses of families are included to aid
in identification. Diagnoses of genera are not in-
cluded, with some exceptions, for these exist in
the literature. Such treatment leads to repetition
but gives more complete descriptive accounts for
individual species.

The general key to suborders, sections, super-
families, and families serves as a rough index,
and an attempt lias been made to arrange it

"phylogenetically". Other keys to subfamilies,
genera, and species are either combined or sepa-
rate depending on number of genera or species in-
volved, and these keys are scattered throughout
the text.

There is a tendency in carcinology to assume
a specialized background on the part of readers,
and beginners may find themselves troubled with
terms. A number of monographs have included
introductory glossaries and figures with detailed
labeling as aids, but these are not always ade-
quate because terminology in various suborders
and sections lacks consistency.

An illustration of inconsistency follows : Among
shrimps, the pereiopods are often called the first,
second, third, fourth, and fifth walking legs.
Among crabs, the tendency is to call the first
pereiopods, chelipeds, because they are almost in-
variably larger than the remaining legs and are
the only chelate pair (except in anomuran and
some dromiid crabs). The remaining pereiopods
are then termed the first, second, third, and fourth
walking legs. This inconsistency seems firmly
entrenched and it is based on functional mor-
phology, the shrimps tending to have five pairs of
legs functionally adapted to walking, but. most
crabs only four. Because many shrimps do not
walk, legs in this group herein have been called
"legs," the term "walking legs" being reserved
for crabs. Hopefully, the use of explanatory fig-
ures adapted from existing works, together with
the glossary, will resolve most of such difficulties

In the species accounts, no attempt has been
made to include complete synonymies. A great
deal of spadework by recent specialists has made
abbreviation of synonymies desirable and prac-
tical; therefore, most are restricted to citation of
original description, Hay and Shore (where appli-
cable),, and work of the most recent reviser.

Many descriptions which Hay and Shore wrote
have been paraphrased, and many measurements,
descriptions of color, and ecological notes have
been included essentially unchanged. When avail-
able, more recent information has been used, and
for this I have depended heavily on Rathbun
(1918b, 1925, 1930a, 1937), Schmitt (1935a), and
Holthuis (1951a, 1952, 1959) for key characters,
color notes, and depth and latitudinal ranges.
For these works, specific citations in the text have
often l>een excluded for the sake of brevity.

FISH AND WILDLIFE SERVICE

ZOOGEOGRAPHIC CONSIDERATIONS

Though the original title implied a local list,
the handbook included an assemblage that is quite
widespread. Hay and Shore justly termed it a
virtual descriptive list of decapod crustaceans of
the Middle Atlantic coast, in large measure tilling
but continuing in part from northwestern Florida
the gap between various lists of New England,
New York, and New Jersey crustaceans, and the
Puerto Rican list (Rathbun, 1901). The assem-
blage treated, both by Hay and Shore (in the
original) and this revised version, has a lati-
tudinal range extending primarily from Cape
Hatteras, N.C., to northeastern Florida (tig. 1),
to Texas; it is encompassed in a more generalized
assemblage sometimes recognized as the Caro-
linian province (Hedgpeth, 1953). Primarily
Antillean in its affinities, the Carolinian province
is distinct from the Virginian province to the
north and this fact has been emphasized by numer-
ous authors.

Bathymetric limits included in this revised
handbook are altered somewhat from the original.
Species which occur from the heads of estuaries
to the 100-fathom contour are included. Fresh-
water decapods, included in the original, have
been excluded because they never occur in the
marine environment. Species that occur only
beyond the 100-fathom line more properly belong
to a deep-sea fauna that ranges far beyond the
Carolinian province, and are not included.

Arbitrary limits are difficult to establish. Judg-
ments undoubtedly will differ as to what is extra-
limital and what is not. For some species with
uncertain distributional limits, a list of extra-
limital species has been included.

An analysis of the decapod crustacean element
in the Carolinian fauna is given by family in
table 1. Here, categories chosen for limits in geo-
graphic range are used broadly, especially at their
southern extremities. For economy of space, the
term "South America" can mean either the north-
ern or southern Atlantic shores of the continent,
but details are given in the species accounts. Our
interest here centers primarily on the eastern coast
of North America, and on natural boundaries or
barriers that exist on this stretch of coast.

It is apparent that a small number (6.8 percent)
of Carolinian decapods are northern in affinity,
extending to southern Florida in one case (Cancer

borealis). To this group, Cape Cod is no barrier,
but to another group (12.7 percent) it is a barrier
to northward extension into upper New England
and the Maritime Provinces of Canada.

Totals are given for species extending north-
ward to the Middle Atlantic States (9.1 percent).
Many of these records are for accidental or sea-
sonal occurrence; i.e., species whose northern
limits of range might well be set at Cape Hatteras.
But there are other species in the group which
must be permanent residents in those latitudes
and are not dependent on annual repopulation
from breeding stock to the south.

Cape Hatteras is a barrier to northward dis-
tribution of shallow-water forms. Here, warm
water of the Gulf Stream meets the cold Labrador
Current to be deflected seaward (Hutchins, 1947),
and 27.7 percent of the decapods are apparently
unable to bridge the narrow transition zone to
colder water.

Cape Lookout, surprisingly, seems to be a
greater barrier to northward extension of range
among Antillean species (31.4 percent) than Cape
Hatteras. This barrier may be real, or it may
be that fauna] limits fluctuate between these capes
as a consequence of natural events. More likely is
the fact that far more collecting has been done
near Cape Lookout than at Cape Hatteras because
of the nearness of marine laboratories to the
former.

Species showing distributions reaching north-
ward only to Charleston, S.C., (4.5 percent) are
probably southern species with accidental records
at that latitude, for there is no apparent barrier
to dispersal in that area. Eastern and western
Atlantic forms are equally small in number (4.5
percent) .

Cosmopolitan species (1.8 percent) are few, as
are endemic species (1.4 percent).

Aside from the above patterns of distribution,
a number of species ranging along the Atlantic
coast and the Gulf coast to Texas have a disjunct
distribution in peninsular Florida. The number
of these species is conservatively estimated, from
literature records, at 10 percent of the total. This
type of distribution, discussed at length by Hedg-
peth (1953), shows a fairly recent separation of
Gulf elements from the Atlantic portion of the
species by emergence of peninsular Florida, but
with the two areas being climatically equivalent

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

90*

30'

20*

50*

Chtsaptakt 8

ATLANTIC

Rio
Grand* '

G U L

MEXICO

OCEAN

CARIBBEAN SEA

t St L.d.

' f So. H

33™

PACIFIC OCEAN

A mat on R. .

A o-

100* 90' 80° 70* 60° 50°

Fiquhe 1. — Area of western North Atlantic Ocean, including portions of eastern North America, Middle America, and
northern South America, covering centers of distribution for most species treated in this handbook.

FISH AND WILDLIFE SERVICE

(Hutchins, 1947). It is also clear, from families
represented in this group, that many are relatively
sedentary, at least as adults.

MATERIALS STUDIED

Materials studied at the U.S. National Museum
(USNM) include recent records resulting from
exploratory work by the vessels Pelican, Alba-
tross III, Combat, Oregon, and Silver Bay, as
well as records of collections by private indi-
viduals. Specimens studied were from the USNM,
the Charleston Museum, Charleston, and Bears
Bluff Laboratories, Wadmalaw Island, S.C., The
University of North Carolina Institute of Fish-
eries Research ( IFR) , and various collections pro-
vided by Duke University Marine Laboratory and
the U.S. Fish and Wildlife Service, Bureau of
Commercial Fisheries Biological Laboratory,
Beaufort, N.C. Remnants of Hay and Shore's
collections were also examined and are now housed
at the IFR.

MEASUREMENTS

Measurements for individuals considered adult
are either from the literature or from specimens
examined. Sizes recorded usually represent the
maximum. Width of the brachyuran carapace is
the width including lateral spines. Length of
shrimps includes the rostrum.

EXTRALIMITAL AND INDETERMINATE SPECIES

The following list includes species having
doubtful position in the Carolinian fauna. Some
range primarily in deep water, occurring inci-
dentally on the Continental Shelf. Others have
a range limited to shallow waters distant from
the Carolinas. Some are included because Hay
and Shore mentioned them, and the remainder
have a doubtful taxonomic status.

Penaeopsis megalops (Smith). North Carolina,
through Gulf of Mexico to Surinam; 150-200+
fathoms.

Sicyonia sp. (Lunz, 1945). A distinct specimen
from Beaufort River, near Parris Island, S.C.,
has been described but not named (Charleston
Museum No. 35.131.5(a)).

Hippolyte coeruleseens (Fabr.). Central At-
lantic Ocean, Bermuda, North Carolina to

Florida, Azores, Canary and Cape Verde Islands,
Gulf of Guinea and S. Angola, doubtful from
Cape Horn region (Sivertsen and Holthuis, 1956).
A single mutilated male from Sneads Ferry, N.C,
is in the U.S. National Museum.

Homarus americanus H. Milne Edwards. Lab-
rador to North Carolina; shallow water to 100+
fathoms. The American lobster is not normally
found south of Cape Hatteras, but lobsters are
frequently taken off Cape Henry, Va. For in-
stance, one 5V2-lb. and two 8-10-lb. lobsters were
taken by the trawler Ensign approximately 45
miles E.N.E. Oregon Inlet, N.C, at 38-15 fathoms,
January 21, 1963. In December 1958, an American
lobster was caught in a crab pot near Cedar
Island, N.C. Mr. Clayton Fulcher, Atlantic, N.C,
reported that he tried to get the specimen, but
this prize was eaten by the fisherman's family.
Hay and Shore (1918) cited one doubtful occur-
rence of the lobster near Beaufort, N.C.

Munula longipes H. Milne Edwards. South
Carolina to Curacao; 154-338 fathoms (Schmitt,
1935a).

Pagurus cokeri Hay. South of Cape Lookout,
N.C, to eastern Gulf of Mexico; approximately
150-200 fathoms.

Catapagurus sharreri Milne Edwards. Between
Capes Hatteras and Lookout, N.C, to Barbados;
87-221 fathoms.

Latreillia elegans Roux. Both sides of North
Atlantic Ocean, Mediterranean Sea, Natal ; 70-200
fathoms (Rathbun, 1937).

Portunus ventralw (Milne Edwards). Georgia
or Florida to Brazil ; surface and near shore
(Rathbun, 1930a).

Portunus sebae (Milne Edwards). Hay and
Shore (1918) cited reports of this species in the
Carolinas. Gulf of Mexico and Florida Straits to
Brazil, Bermuda; surface to 15 fathoms.

Callinectes danae Smith. Status of this species
on the southeastern coast of the United States
needs clarification for there is no clear distinction
there between it and C. ornatus. Indian River In-
let, Fla. to Brazil ; shallow water to a few
fathoms.

Parapinnixa hendersoni Rathbun. This species
is questionably recorded from lat. 34°34' N. long.
75°50' W., southeast of Cape Lookout, N.C, 35

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 O — 65 2

Table 1. — Geographic ranges oj decapod crustaceans

(Lower portion oi table shows combined totals of species with ranges limited by natural

Families

Number

of
species

North of Cape
Cod to Florida,

Gulf of

Mexico, West

Indies and

South America

Cape Cod to
east Gulf of
Mexico and
West Indies

Cape Cod to
west Gulf of

Mexico

and South

America

Middle

Atlantic

States to

west Gulf and

Caribbean

Middle
Atlantic
States to

South
America

Hatteras to
east Gulf of

Mexico, West
Indies, and

South America

Hatteras

through Gulf

of Mexico and

West Indies

to South

America

Hatteras to
west Gulf
of Mexico

17
1

14
1

10
2
8
1
1
1
1
4
2
8
3

21
3
2
1
3
1
6
9

13
2

24
3

10
2
6
4

30
6

2
1

Pasiphaeidae.. .

Gnathophyllidae

2
1

H ippoly tidae

Processidae .

Pandalidae ._ - -

Crangonidae

Palinuridae

Scyllaridae .

Galatheidae

Callianassidae. _

Paguridae .

Albuneidae. ..

Raninidae

Dromiidae. _

Homolidae

1
1

3
3

Portunidae

2
2
3

Cancridae

Xanthidae.. _

6
1

Goneplacidae .

Pinnotheridae. .

Palicidae..

Grapsidae

1
1

Ocypodidae__ .

Majidae.

5
2

Parthenopidae

Total ..

220

North Cape
Cod-South

Cape Cod-South

Middle Atlantic-South

Hatteras-South

Combined total..

Percent total .

99.9

6.8

12.7

9. 1

27.7

fathoms (U.S. National Museum). Cuba, Gulf of
Mexico; 30-35 fathoms.

Parapinnixa beaufortensis Rathbun. The only
specimen of this species known is the holotype
from fishing grounds, '20 miles off Beaufort Inlet,
N.C. Rathbun (1918b) doubtfully referred this
form to the genus Parapinnixa and believed that
it was a postlarval stage of an unknown species
because of small size, relatively large eyes, hairi-
ness of legs and carapace, and thin gripping edges
of the fingers suggesting that in another molt or
two gaping fingers might emerge. I believe that
it may be a young Palicus.

Notolopas lainellatus Stimpson. Rathbun
( 1930a) gave one occurrence of an- ovigerous fe-
male off Beaufort, N.C. Sonora, Mexico, to Ecua-
dor (Garth, 1958).

A large amount of unidentified material is in
existing collections and some of this contains
undescribed species. It is expected that the in-
crease in oceanographic research in Southeastern
United States will soon add to knowledge of deca-
pod crustaceans in the area.

GLOSSARY

Many of the structures listed alphabetically and
defined are shown schematically on figures

FISH AND WILDLIFE SERVICE

occurring in the Carolinas, arranged by family

barriers. Numbers marked with an asterisk duplicate numbers in adjacent columns)

Eastern and
western
Atlantic

Pacific

Cosmopolitan

Endemic

Disjunct at

Florida
Peninsula

Lookout to east
Gulf of Mexico
and West Indies

Lookout to east
Gull of Mexico,
West Indies, and
South America

Lookout through
Gulf of Mexico,

West Indies, and
South America

Charleston to

West Indies,

Texas or South

America

1 + *1

1 (restr.)

1
5

1
2

3
2
1

6
2
1

6
2

10+ *1

*23

East and west
Atlantic

Cosmopolitan

Endemic

Lookout-South

Charleston-
South

10+*1

4.5

1. 8

1.4

*10. 5

31.4

4.5

2, 3, and 4. Other terms not listed are shown on
these figures.

Acicle. — Antennal scale which is reduced to a
spine.

Afferent channels. — Openings through which
water passes to the gills. In brachyuran crabs,
usually opening behind the pterygostomian re-
gions and in front of chelipeds except in certain
Oxystomata in which they open at anterolateral
angles of palate or endostome.

Antennal spine. — Spine on anterior edge of
carapace immediately below orbit adjacent to base
of antenna (fig. 2).

Anterolateral teeth. — Teeth on anterolateral
border of crabs between orbit and lateral spine,
exclusive of outer orbital teeth.

Apodeme. — Any cuticular ingrowth of body
wall.

Appendix interna. — Small separate branch on
medial side of pleopodal endopodite tipped with
hooks which interlock with opposite member in
swimming.

Appendix masculina.— Accessory male organ
located medially on second pair of pleopods be-
tween endopodite and appendix interna.

Arthrobranchiae.— Gills attached to articular

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

membrane between the coxa of an appendage and
the body wall.

Basis (basipodite) . — Second article (from the
body) of a leg or maxilliped. Sixth segment from
distal end of the limb.

Basicerite. — Spine on dorsal side of basis of an-
tenna ; sometimes more lateral than dorsal.

Branchiocardiac groove. — Groove separating
branchial and cardiac regions.

Braiwhiostegal spine. — Spine on anterior edge
of carapace, or near it, immediately below
branchiostegal groove (fig. 2).

Branchiostegite. — Part of carapace not coa-
lesced ventrally with the thoracic somites, but
overhanging on each side as a covering for cham-
ber in which the gills are concealed.

Buccal cavity. — Cavity on ventral surface of
body in which the mouthparts are situated; it is
bounded anteriorly by the epistome, laterally by
the free edges of the carapace.

Carina. — A keellike ridge or prominence.

Carpus (carpopodife). — Third article from the
distal end of a leg.

Cervical groove. — Complex groove or series of
grooves running across carapace. It is transverse
at the middle, then turns obliquely forward (and
outward in brachyurans) to the anterolateral
margin.

Chela. — Arrangement of the distal two articles
of a crustacean limb by which the terminal ele-
ment is opposed to the element which precedes it,
so that the appendage is adapted for grasping.

In a true chela, the elements are shaped as
lingers which close against each other.

In a subchela, the terminal article (dactyl)
usually closes against the distal surface of the
penultimate article (propodus).

('In lipids. — Pair or pairs of thoracic legs im-
mediately behind the maxillipeds. They bear
chelae, or pincer-claws, and are often stouter,
sometimes much stouter, than the succeeding walk-
ing legs.

Co.ru (coxopodite) .- First or proximal article
of a leg or maxilliped.

Dactyl (dactylus or dactylopodite) . — Terminal
or distal article of a leg or maxilliped. The dactyl
is the movable finger of a cheliped.

Efferent channels. — Channels through which
water passes from the gills. These open at the
sides of the endostome, except in the superfamily

Oxystomata in which they open at the middle of
the endostome.

Endognath. — Inner or principal branch of a
maxilliped.

Endopodite. — Medial ramus of a biramous ap-
pendage.

Endostome. — Part of the epistome which forms
the palate in brachyurans and is usually separated
from the epistome proper by a transverse ridge.

Epibranchial (epibranchial region) . — Portion
of the porcellanid (crab) carapace which is situ-
ated behind the orbit and above the metabranchial
region. The region situated between the cervical
groove and the linea anomurica. There is often a
strong spine on the region, referred to as the
epibranchial spine.

Epigastric lobes. — Anterior lobes or subregions
of the gastric region.

Epimere. — A lateral part of the wall of body
somites situated between the tergum and the in-
sertion of appendages.

Epipodite. — Outgrowth of the first seven
thoracic coxae.

Epistome. — The antennal sternum is mainly
represented by the epistome, a plate of varying
shape, lying between the labrum and the bases of
the antennae. In Natantia the epistome is com-
partively narrow, and on each side is separated
from the lateral portions of the carapace by the
exhalant branchial channels. In most of the Rep-
tantia, the epistome is broad and comes in con-
tact with the carapace on each side; in the
Brachyura, it becomes firmly united with the
carapace. In this way, there is defined, more or
less distinctly, a buccal frame within which lie
the mouth parts, and which in most Brachyura is
closed by the operculiform third maxillipeds. The
sides of this buccal frame are formed by the free
anterolateral margins of the carapace.

Exognath. — Outer or secondary branch of a
maxilliped.

Exopodite. — Lateral ramus of a biramous
appendage.

Fingers (digits).- Narrow scissorlike blades of
the claw end of a cheliped, with the movable linger
being the dactyl, and the immovable finger the
terminal pari of the propodus.

Front. — Frontal portion of carapace ; thai por-
tion of the carapace of a crab which lies between
the orbits.

FISH AND WILDLIFE SERVICE

prbit eyestalk

rostrum

abdominal segments

subchela

subdivided carpus

telson

Figi're 2. — Schematic drawing of shrimp in lateral view; ai., appendix interna; a.s., antennal spine;
a. sc, antennal scale; b., basis; b.s., branchiostegal spine; cp., carpus; ex., coxa; d., dactyl;
end., endopod ; ep„ epipod ; ex., exopod ; h.s., hepatic spine: i.. ischium; m.. merus: p.. pro-
podus ; p.g., postorbital groove; p.s., pterygostomian spine; s.s., supraorbital spine; St., styloce-
rite. (Modified after Holthuis, 1955 ; Schmitt, 1921.)

Frontal teeth. — True frontal teeth; those teeth
originating on the front but exclusive of the inner
orbital teeth.

Gastric region. — Large median area, in the crab
carapace, bounded behind by the cervical suture,
laterally by the hepatic regions, and anteriorly by
the frontoorbital regions. It is divisible into the
following subregions or lobes: epigastric, proto-
gastric, mesogastric, metagastric, and urogastric.

Genital region. — See urogastric lobe.

Hand (chela). — Propodus and dactyl of the
cheliped.

Hepatic region. — A small (paired) subtriangu-
lar, anterolateral region, wedged between bran-
chial and gastric regions, and either margin of
carapace or margin of orbit in Brachyura.

Hepatic spine. — Spine on hepatic region in
Natania (fig. 2).

Ischium (ischiopodite). — Fifth article of a leg
or maxilliped from the distal end. It is usually the
first large article of the maxilliped.

Merus (meropodite). — Fourth article from the
distal end of a leg or maxilliped. It is sometimes
called the arm of a cheliped.

Mesogastric lobe. — Lobe or subregion which is
the median division of the gastric region, pen-
tagonal in form, and with a long, narrow, anterior
prolongation.

Metabranchial (metabranchial region). — That
region of the porcellanid (crab) carapace which is
situated below the linea anomurica and, therefore,
not completely united with the main portion of
the carapace.

Metagastric lobe. — Posterolateral lobe or sub-
region of the gastric region; often not defined.

Ocellus. — Little eye, distinct from the main
organ of vision.

Orbit. — Cavity in the carapace containing the
eye.

Orbital region. — Narrow space bordering upper
margin of orbit ; not always distinguishable.

Palate. — Roof of buccal cavity in crabs.

Palm. — Proximal portion of propodus of chela.

Petasma. — Endopodite of the first pleopods in
male Penaeidae. It takes the form of a compli-
cated membranous plate bearing coupling hooks
medially which interlock with the member of the

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

cheliped

anterolateral border

Figure 3. — Schematic drawing of brachyuran crab in dorsal view ; areas of carapace indicated ; legs
of right side only shown ; b., basis ; cp., carpus ; d., dactyl ; i., ischium ; m.. merus ; p., propodus.

opposite side. The petasma may terminate distally
in various combinations of complex-shaped lobes.
According to position, these have been termed:
distolateral, distoventral, and distomedian. Addi-
tional complex processes may also be present.

Pleurobranchia. — Gills attached to lateral wall
of body dorsal to the articulation of an appendage.

Podobranchia. — Gills attached to the coxa of an
appendage.

Postorbital groove. — Groove on carapace behind
orbit, and more or less parallel to margin of orbit
(% 2).

Propodus (protopodite). — Second article from
the distal end of a leg or maxilliped. In a cheliped,
t he propodus consists of a palmar portion and a
narrower, immovable finger.

Prosartema (dorsal eye brush). — Long, thin,
ciliated lobe arising dorsally from proximomedial
border of first antennular segment and extending
anteriorly ; found in family Penaeidae.

Protogastric lobe. — Lobes or subregions which
are the anterolateral lobes of the gastric region.

Protopodite. — Peduncle of an appendage; in
unmodified form, it consists of one coxal and one
basal article.

Pterygostomian region. — Triangular space on
ventral surface of carapace, on either side of buc-
cal cavity in Brachyura. Region at anterolateral
corner of carapace in Natantia.

Pterygostomian spine. — Spine at anterolateral
(anteroventral) corner or border of carapace
(fig- 2).

FISH AND WILDLIFE SERVICE

cheliped

antennule
antenna \
eye

suborbital

thoracic sternum

Figure 4. — Schematic drawing of braehyuran crab in ventral view ; areas of carapace indicated ; legs
of left side only shown ; b., basis ; cp., carpus ; ex., coxa ; d., dactyl ; end., endognath ; ex.,
exognath ; i., ischium ; m.., merus ; p., propodus.

Scaphocerite. — Antennal scale (fig. 2).

Stylocerite. — Spine or rounded lobe, on lateral
aspect of basal article of antennules.

Subhepatic region. — Area below the hepatic
region and below the anterolateral border of the
carapace.

Suborbital spine. — Spine on lower rim of orbit
(% 2).

Supraorbital spine. — Spine above and behind
orbit (fig. 2).

Telson. — Terminal somite of the abdomen ex-
cept in the Brachyura.

Tergite. — Dorsal plate of a segment.

Thelycum. — External seminal receptacle, vari-
ously developed, lying on sternum of the thorax
and formed by outgrowths from the last and next

to last thoracic somites.

Urogastric lobe. — Posteromedian lobe or sub-
region of the gastric region ; sometimes called the
genital region.

ORDER DECAPODA

Caridoid facies either retained or greatly modi-
fied. Exopodite of maxilla (scaphognathite or
bailer) large. First three pairs of thoracic limbs
specialized as maxillipeds. Gills typically in sev-
eral series, attached to coxae of thoracic limbs, to
their articular membranes, and to lateral walls of
thoracic somites (podo-, arthro-, and pleuro-
branchia) ; rarely absent. Young rarely hatched
in nauplius stage (Caiman, 1909).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

KEY TO SUBORDERS, SECTIONS, SUPERFAMILIES, AND FAMILIES OF DECAPOD
CRUSTACEANS FOUND IN THE CAROLINAS

a. General form shrimplike; abdomen well developed and usually with carapace compressed; pleopods always present

in full number and used for swimming Suborder Natantia (p. 14) .

b. Pleura of second abdominal segment not overlapping those of first segment Section Penaeidea (p. 14).

c. First three pairs of legs chelate, all five pairs of legs well developed Family Penaeidae (p. 14).

cc. First three pairs of legs chelate, last two pairs of legs small or wanting Family Sergestidae (p. 38).

bb. Pleura of second abdominal segment overlapping those of first segment Section Caridea (p. 41).

c. First pair of legs chelate or simple.

d. Fingers of chelae on first and second legs slender, cutting e Iges all pectinate Family Pasiphaeidae (p. 41).

dd. Fingers of chelae on first and second legs variable in thickness; cutting edges of fingers of chelae not all
pectinate,
e. Carpus of second pair of legs entire; first pair of legs always with well-developed chelae.

f. Third pairs of maxillipeds pediform; body slender in most species Family Palaemonidae (p. 42).

fT. Third pair of maxillipeds broad, leaflike; body short and thick Family Gnathophyllidae (p. 61).

ee. Carpus of second pair of legs usually subdivided into two or more joints; first pair of legs often asymmetrically
chelate.

f. Chelae of first pair of legs distinct, at least on one side,
g. Each of first legs chelate.

h. Eyestalks short, usually covered by carapace; first pair of legs stronger than second

Family Alpheidae (p. 62).
hh. Eyestalks medium length or long, not covered by carapace; first pair of legs not stronger than second
pair,
i. Rostrum small or wanting; eyestalks long, slender; first two pairs of legs subequal

Family Ogyrididae (p. 74).
ii. Rostrum well developed; eyestalks not abnormally lengthened; second pair of legs usually longer

or stronger than first Family Hippolytidae (p. 76).

gg. Only one of first pair of legs chelate, opposite leg ending in a simple clawlike dactyl

Family Processidae (p. 86).

fT. Chelae of first pair of legs microscopically small or absent Family Pandalidae (p. 87).

cc. First pair of legs subchelate Family Crangonidae (p. 88).

aa. General form lobsterlike or crablike; abdomen either well developed or greatly reduced in size, usually with abdomen

and carapace depressed; pleopods reduced or absent, not used for swimming Suborder Reptantia (p. 90).

b. Abdomen extended, symmetrical, with well-developed tail fan Section Macrura (p. 90).

c. Abdomen well armed, pleura well developed; third pair of legs like first Superfamily Scyllaridea (p. 90).

d. Body subcylindrical; antennae with strongly developed flagella Family Palinuridae (p. 91).

dd. Body strongly depressed; antennae short, squamiform Family Scyllaridae (p. 94).

cc. Abdomen more or less membranous; pleura small or wanting; third legs unlike first, never chelate

Superfamily Thalassinidea;
Family Callianassidae (p. 99).
bb. Abdomen bent upon itself or flexed beneath thorax; pleura usually small or wanting; tail fan variable in develop-
» ment; (third pair of legs unlike first, never chelate).

c. Uropods usually present, often reduced in size, sometimes united with telson; last thoracic sternite free; carapace

not apparently fused with epistome Section Anomura (p. 104).

d. Abdomen well developed.

e. Abdomen symmetrical, more or less flexed beneath thorax; body depressed; tail fan well developed

Superfamily Galatheidea (p. 104).

f. Form somewhat lobsterlike; rostrum well developed Family Galatheidae (p. 104).

ff. Form crablike (Euceramus elongate) ; rostrum short and broad or wanting-. Family Porcellanidae (p. 106).
ee. Abdomen asymmetrical; tail fan reduced and adapted for holding body in hollow objects

Superfamily Paguridea; Family Paguridae (p. 114).

dd. Abdomen much reduced in size and flexed under thorax Superfamily Hippidea (p. 136).

e. First pair of legs subchelate; carapace depressed Family Albuneidae (p. 136).

ee. First pair of legs simple; carapace subcylindrical Family Hippidae (p. 139).

] 2 FISH AND WILDLIFE SERVICE

KEY TO SUBORDERS, SECTIONS, SUPERFAMILIES, AND FAMILIES OP DECAPOD CRUSTACEANS POUND

IN THE CAROLINAS— Continued

aa. General form lobsterlike or crablike — Continued

bb. Abdomen bent upon itself or flexed beneath thorax — Continued

cc. Uropods rarely present, never biramous; abdomen small, permanently flexed beneath thorax; carapace fused

with epistome; (first pair of legs always chelate or subchelate) Section Brachyura (p. 142).

d. Anterior thoracic sterna very broad, posterior thoracic sterna narrow and keellike; posterior thoracic epimera

largely exposed by reduction of branchiostegite Subsection Gymnopleura; Family Raninidae (p. 142).

dd. Anterior thoracic sterna not usually broad, posterior thoracic sterna not keellike; posterior thoracic epimera
covered by branchiostegite.
e. Buccal frame triangular, prolonged forward to form a gutter; openings of oviducts generally sternal; first

pleopods lacking in female Subsection Oxystomata (p. 146).

f. Afferent branchial openings on either side of endostome Family Leucosiidae (p. 147).

ff. Afferent branchial openings in front of bases of chelipeds Family Calappidae (p. 152).

ee. Buccal frame roughly quadrate; not prolonged forward.

f. Last pair of legs modified in form and dorsal in position; openings of oviducts coxal; first pleopods present

in female Subsection Dromiacea (p. 143).

g. Sternum of female with longitudinal grooves; eyes usually completely sheltered by orbits when retracted

Family Dromiidae (p. 143).
gg. Sternum of female without longitudinal grooves; eyes incompletely or not at all sheltered by orbits

when retracted Family Homolidae (p. 146).

ff . Last pair of legs normal in position (rarely reduced or dorsal, Palicidae) ; openings of oviducts on

sternum; first pleopods lacking in female Subsection Brachygnatha (p. 160).

g. Body of medium width or broad in front; rostrum reduced or wanting.

Superfamily Brachyrhyncha (p. 160).
h. Carpus of third maxillipeds articulating at or near anterointernal angle of merus; body usually round
or transversely oval; openings of vasa deferentia nearly always coxal.

i. Distal articles of last pair of legs broad, thin and paddlelike... Family Portunidae (p. 160).

ii. Distal articles of last pair of legs not paddlelike.

j. Antennules folding longitudinally; outer maxillipeds long, overlapping epistome

Family Cancridae (p. 174).
jj. Antennules folding transversely or obliquely; outer maxillipeds usually not overlapping epistome.
k. Body usually transversely oval; openings of vasa deferentia rarely sternal

Family Xanthidae (p. 176).
kk. Body usually quadrate; openings of vasa deferentia sternal or, if coxal, passing along groove

in sternum Family Goneplacidae (p. 201).

hh. Carpus of third maxillipeds not articulating at or near inner angle of merus; body usually quadrate
(except Pinnotheridae) ; openings of vasa deferentia nearly always sternal; right chela not always
larger than left (except Palicidae).
i. Small, usually commensal crabs with small eyes and orbits; body usually somewhat rounded, adult

females often with carapace somewhat membranous Family Pinnotheridae (p. 203).

ii. Free living crabs with eyes not strikingly reduced; body usually quadrate, adult females with
carapace normal,
j. Last pair of legs dorsally placed and weaker than others; interantennular septum very thin

Family Palicidae (p. 215).
jj. Last pair of legs not dorsally placed; not markedly weaker than others; interantennular septum
not very thin,
k. Front broad; eyestalks of moderate length or short; a gap of varying size between outer maxilli-
peds Family Grapsidae (p. 217).

kk. Front with moderate width; eyestalks long; outer maxillipeds nearly, or quite, closing buccal

area Family Ocypodidae (p. 225).

gg. Body narrowed in front; rostrum usually distinct; orbits often incomplete

Superfamily Oxyrhyncha (p. 235).

h. Chelipeds not much larger than other legs Family Majidae (p. 236).

hh. Chelipeds much larger than other legs Family Parthenopidae (p. 266).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 13

Systematic and Ecological Discussion

Suborder Natantia

Body almost always laterally compressed. Ros-
trum usually compressed and serrated. First
abdominal segment not much smaller than rest.
Antennules generally with stylocerite; antenna]
scale generally large and lamellar. Legs usually
slender, except sometimes a stout chelate limb or
pair, which may be any one of first three pairs;
with basipodite and ischiopodite very rarely
coalesced and with only one fixed point in carpo-
propodal articulation (with some doubtful excep-
tions) ; sometimes withexopodites; podobranchiae
hardly ever present on first three and never on
last two pairs ; male genital apertures in articular
membrane. Pleopods always present in full num-
ber, well developed, used for swimming (Caiman,
1909).

Section Penaeidea

Pleura of second abdominal segment not over-
lapping those of first segment. Antennules gen-
erally with stylocerite. Mandibular palps straight.
First maxillipeds without expansion at base of
exopodite, endopodite long; second maxillipeds
with terminal articles normal; third maxillipeds
with seven articles. Third legs chelate (except
when much reduced), not stouter than first pair.
First pleopods of male bearing sexual apparatus
(Caiman, 1909).

Family Penaeidae

Body somewhat or considerably compressed.
Rostrum usually well developed, laterally com-
pressed, often with teeth. Eyes moderate or
greatly elongate. Antennules with two flagella;
basal article of peduncle hollowed out dorsally
for eye, with stylocerite on basal outer margin.
Mandible with incisor process and palp of one
or two articles. First three pairs of legs similar,
chelate, slender, increasing in length posteriorly;
fourth and fifth legs well developed, simple
(Schmitt, 1921).

Remarks. — For most species treated in this
handbook information on natural history is in-
cluded in the separate species accounts. In the

case of parasites found in certain penaeids, such
citation has proved too cumbersome. Parasites in
this group have been studied only recently. Host
specificity and life cycles of the parasites are im-
perfectly known and identification of some forms
is uncertain. The interested student is referred to
a review of most of the known parasites given
by Hutton, Sogandares-Bernal, Eldred, Ingle, and
Woodburn (1959), and Iversen and Manning
(1959).

Spelling of the name Penaeus and related gen-
eric names has unfortunately not been uniform.
Gunter (1957) reviewed these circumstances and
re-emphasized that under the International Code,
original spelling must be observed. He included a
list of the genera of Penaeidae.

KEY TO SUBFAMILIES IN THE CAROLINAS

a. Postorbital spine present Solenocerinae (p. 14).

aa. Postorbital spine absent.

b. Carapace without a median dentate crest, except

occasionally over eyes Penaeinae (p. 17).

bb. Carapace with a median dentate crest extending
nearly or entirely to posterior margin

Sicyoninae (p. 32).

Subfamily Solenocerinae

Carapace with postorbital spine, cervical groove
extending nearly or quite to dorsum. Ocular
peduncle with a distinct tubercle, a scale at ex-
ternal angle of ocular somite. Antennular pe-
duncle with an enlarged ciliated protuberance on
inner proximal margin of basal article. First
chelipeds with tuft of setae on propodus in both
sexes. Coxae from second maxillipeds to fifth legs
with weakly forked epipodites. ■ A functional
filamentose anterior arthrobranch on 13th somite
(4th leg) ; pleurobranchs behind 9th somite (3d
maxilliped). Exopodites on maxillipeds and legs.
Pleopods, except first pair, biramous. Telson with
well-developed terminal point and a pair of sub-
terminal fixed spines (Burkenroad, 1934b).

KEY TO GENERA AND SPECIES IN THE CAROLINAS

a. Antennular flagella hollowed out medially, chanuellike
in structure Solenocera atlantidis (p. 15).

aa. Antennular flagella not hollowed out medially nor
chanuellike in structure

Bymenapenaeus tropicalia (p. 15).

FISH AND WILDLIFE SERVICE

Genus Solenocera Lucas, 1849

Burkenroad, 1934b, p. 64. — 1936, p. 120. — 1939, p. 6.
Solenocera atlantidis Burkenroad
Figure 5
Solenocera atlantidis Burkenroad, 1939, p. 10.

Recognition characters. — Body compressed, car-
apace deeper than broad; integument thin,
smooth; sides of rostrum and area near base of
rostrum covered with short hairs; carapace with
small pterygostomian spine meeting frontal mar-
gin at right angle, spine sometimes doubled;
postorbital and hepatic spines well developed;
antennal angle acute, more or less toothlike, often
not greatly produced; orbital angle with a distinct
spine on margin; cervical groove reaching mid-
dorsal line; branchiocardiac groove prominent.
Kostrum not reaching distal edge of eye; lower
margin unarmed, convex; with five to seven, us-
ually six, dorsal teeth not counting dagger-shaped
tip, two behind, one above orbital margin, pos-
terior tooth slightly remote from others. Post-
rostral carina not continued beyond crossing of
cervical groove. Antennular flagella slender, about
half as long as body; lower flagellum broader than
upper at hollowed basal portion. Antennal scale
extending no more than one-tenth its length be-
yond antennular peduncle.

Coxa of fifth legs with strong tooth on antero-
medial margin in both sexes.

Abdomen with last three segments carinate;
third to fifth segments cleft posterodorsally at
midline; sixth segment with a spine at middorsal
posterior and posterolateral corners and a tooth-
like projection at middle of distolateral edge.
Telson short, broad, lateral spines large. Exopods
of uropods with no spine at distolateral corner.

Measurements. — Length of body : large male,
37 mm. ; large female, 56 mm.

Variations. — The epipodites are usually mitten-
shaped, but sometimes more distinctly forked, the
thumb or inferior branch never exceeding the
proximal or palmar portion of the blade, exclusive
of the peduncle.

Color. — Orange red, color most concentrated as
bands across posterior parts of abdominal tergites
(Burkenroad, 1939).

Habitat. — Mud, shell, and coral bottoms ; 10 to
180 fathoms.

Type locality. — Gulf of Mexico off Alabama
(Atlantis station 2813, roughly lat. 30° N. long.
88° W.), 19 fathoms.

Known range. — Cape Hatteras, N.C., to near
Campeche, Mexico; Surinam (Hildebrand, 1955;
Holthuis, 1959).

Remarks. — Females with well-ripened ovaries
have been taken in March off Alabama (Burken-
road, 1939).

Genus Hymenopenaeus Smith, 1882

Burkenroad, 1936, p. 102.
Hymenopenaeus tropicalis (Bouvier)
Figures 6-7

Parartemesia tropicalis Bouvier, 1905, p. 749.

Haliporus tropicalis: Bouvier, 1906, p. 4. — Milne Edwards and
Bouvier, 1909, p. 247, pi. 3, figs. 1-9, text-figs. 45-54.

Hymenopenaeus tropicalis: Burkenroad, 1936, p. 102.

Solenocera weymouthi Lindner and Anderson, 1941, p. 181,
fig. 1.

Recognition characters. — Body robust, laterally
compressed; integument thin, polished, except
finely setose at sides of rostrum and area near base
of rostrum; carapace deeper than broad with
antennal, hepatic, and postorbital spines well de-
veloped, a small stout spine on orbital margin;
cervical groove extending nearly to middorsal
line; branchiocardiac groove extending from near
anterolateral corner to level of base of first legs.
Bostral crest not extending beyond level of cervi-
cal groove, armed above with 7 to 10 teeth exclud-
ing rostral tip, posterior tooth slightly remote
from others; rostrum reaching about to distal
edge of eye, straight or slightly upturned at tip,
lower edge convex, unarmed, ciliated. Prosartema
prominent, hairy, extending to or beyond middle
of second segment of antennular peduncle. An-
tennular flagella somewhat flattened, upper ramus
about one-third diameter of lower at base. Anten-
nal flagella about three times body length.

Female with projections on coxae of last three
pairs of legs, first pair posteromedial and blunt
pointed ; second pair medial, bladelike, with thin,
stylif orm posterior projection ; third pair medial,
broad, bladelike, partially covering thelycum.
Thelycum setose, posterior lateral lobes united;
middle lobes rounded, discrete; anterior lobes
closely approximated at midline, partially cov-
ered by coxal projections of fourth legs.

Abdomen with middorsal carina low and faint
on third segment, progressively more prominent

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure 5. — Solenocera atlantirlis Burkenroad. A, animal in lateral view: B. urupods and telson in

dorsal view ; A-B X 2.5.

Figure 6. — Hymenopcnaeiis tropiralis (Bouvier). A, animal in lateral view; B. uropodi

in dorsal view ; A-B X 1.25.

and telson

posteriorly ; segments three to five variably cleft,
posterodorsally ; sixth segment with a small mid-
dorsal posterior spine, a spine at posterolateral
corners, and a toothlike projection at middle of
distolateral edge. Telson tapering to a strong
point flanked on each side by a strong, fixed, sub-
terminal spine; middorsal groove bifurcated at
midlength, forks ending medial to base of fixed
spines. Exopods of uropods with small spine at
distolateral corner. Male with large, membranous,
complexly folded petasma; tips of petasma reach-
ing base of second legs.

Measurements. — Length of body: large male,
56 mm. ; large female, 92 mm.

Color. — Red.

Habitat. — Seventeen to 200 fathoms, rarely
deeper; usually inside 100- fa thorn curve.

Type locality. — Florida Bank (Gulf of Mexi-
co), lat, 26°31' N. long. 85°03' W.

Known range. — Cape Hatteras, N.C., to Gulf
of Mexico, off Alabama.

Remarks. — Burkenroad considered it likely (in
Anderson and Lindner, 1945) that Solenocera

Figure 7. — Bymenopt run us
tropicalis i Bouvier).
Petasma of male in ven-
tral view. 1 mm. indi-
cated.

FISH AND WILDLIFE SERVICE

weymouthi Linder and Anderson was identical jections, but with a more or less conspicuous pair

with Hymenopenaeus tropicalis (Bouvier). Com- of projections from lateral portions; ocular pe-

parison of a number of specimens of both forms duncles with some inconspicuous vestiges of a

leads me to regard them as identical. Prominence median tubercle. Proximomedian margin of an-

of the coxal projections on the last three pairs of tennular peduncle produced as an elongate scale,

legs in females varies with age. Those illustrated First chelipeds with tuft of setae on propodus in

by Lindner and Anderson appear not so well de- both sexes. No podobranchs behind eighth somite

veloped as in fully matured H. tropicalis females. (second maxillipeds). No epipodites behind 12th

somite (3d legs) ; epipodites usually forked. No

Subfamily Penaeinae filamentous anterior arthrobranch on 13th somite

Carapace without post orbital spine; cervical (4th leg). Pleopods, except first pair, biramous.

groove not extending to dorsum. Ocular somite Telson with well-developed terminal spine (Burk-

without a greatly produced pair of median pro- enroad, 1934b).

KEY TO GENERA AND SPECIES (PARTIAL) IN THE CAROLINAS

a. Rostrum with ventral teeth Penaeus (p. 17).

aa. Rostrum without ventral teeth,
b. Telson with subtenninal pair of fixed spines.

c. Carapace with longitudinal and transverse sutures present; body nearly smooth

Parapenaeus longirostris (p. 27).

cc. Carapace without longitudinal and transverse sutures; body pubescent Penaeopsis goodei (p. 29).

bb. Telson with no subterminal pair of fixed spines.

c. Rostrum slender, sinuous, as long as or longer than carapace, with basal thin, high crest armed with five teeth

plus an isolated epigastric tooth Xiphopenevs kroyeri (p. 30).

cc. Rostrum not slender and sinuous, about half length of carapace, dorsal teeth evenly spaced

Traeliypeneus eonstrietus (p. 31).

KEYS TO SPECIES IN THE CAROLINAS
Genus Penaeus Fabricius, 1798

Burkenrod, 1934b. — Hemming, 1958b.

Adults

( Based on keys by Anderson and Lindner, 1945, and Voss, 1955)

a. Lateral rostral grooves not extending beyond base of rostrum . — setifcrim (p. 18).

aa. Lateral rostral grooves reaching almost to posterior margin of carapace.

b. Petasma of male with external edge of distoventral lobe armed with 2 to 12, usually 4 to 7. spinules; teeth of
internal edge of lobe long and sharp in close-set group of 6 to 16. Thelycum of female with anteromedian corners
of lateral plates moderately gaping, not covering carina of posteromedian part of median plate on 13th body

somite (4th legs) duorarum (p. 21).

bb. Petasma of male with external edge of distoventral lobe smooth, incurved, teeth of internal edge of lobe small,
in close-set group. Thelycum of female with anteromedian corners of lateral plates widely gaping, exposing forked
carina of posteromedian plate on 13th body somite (4th legs) aztccus (p. 24).

JUVENILES BETWEEN 17 AND 47 MM. TOTAL LENGTH, LIVE OR FRESHLY PRESERVED

(Williams, 1953)
a. Lateral rostral grooves not reaching almost to posterior margin of carapace ; rostrum prominent and slightly upturned
at tip in individuals above 22 mm. total length. Ground color light gray, sometimes with greenish cast in shrimp
taken from beds of vegetation; ehromatophores (widely spaced except on spines, ridges, and uropods) colored slate-
blue and brown; uropods with reddish-brown to brown areas distally setiferus (p. 18).

aa. Lateral rostral grooves reaching almost to posterior margin of carapace (shallow in 17 mm. individuals). Color
gray to light brown, sometimes with greenish cast in shrimp taken from beds of vegetation ; ehromatophores numerous
and closely spaced, often in bands or patches.

b. Rostrum usually not upturned at tip. ehromatophores slate-blue and brown ; usually with conspicuously pig-
mented lateral spot at juncture of third and fourth abdominal segments ; uropods with uniform sprinkling of
ehromatophores, degree of transparency uniform throughout (color more dense in older individuals)

duorarum (p. 21).

bb. Rostrum usually slightly upturned and attenuate at tip. ehromatophores brown and olive-green ; uropods' with

reddish-brown to brown areas distally azteciis (p. 24).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 17

Penaeus setiferus (Linn.)- White shrimp

Figures 8-9

.' Cancer setiferus Linnaeus [In part]. 1767, p. 1054.
Penaeus setiferus: Hay and Shore, 1918, p. 378, pi. 25, fig. 5. —
Burkenroad, 1939, p. 17 (rev.).— Holthuis, 1962, pp. 115-118.
Penaeus fluviatilis: Gunter, 1962a, b, pp. 107-114 ; 118-121.

Recognition characters. — Integument thin, pol-
ished, translucent. Carapace with a high median
carina continuous anteriorly with rostrum and
extending back about two-thirds length of cara-
pace; not grooved posteriorly, with lateral grooves
terminating near posterior tooth in rostral series ;
armed with 9 or 10 sharp teeth dorsaliy, anterior
6 teeth on rostrum proper; postocular crest absent.
Rostrum with tip long, slender, unarmed, up-
curved distally, apex sometimes depressed, first
dorsal tooth near distal edge of eye, ventral edge
armed with two teeth. Antennal spine surmount-
ing lateral carina extending upward short distance
from hepatic spine. Medial antennular flagellum
of adult male dorsoventrally flattened and armed
dorsaliy with two sizes of teeth.

Anterolateral marginal ridges of last thoracic
sternite of female extending conspicuously mediae!
near middle of segment making an interrupted
crescentic transverse ridge with concavity directed
forward; posterior portion of sternite with con-
spicuous pair of fleshy protuberances. Posterior

margin of 12th sternite with pair of posteromedial
convexities extending almost level with median
portion of margin.

Abdomen with fourth to sixth segments cari-
nate; carina of sixth segment with a groove on
each side. Telson with deep median groove and an
acuminate tip. Ventral margin of pleura of first
abdominal segment almost straight. Petasma of
male with diagonal ridge across face of clisto-
lateral lobe.

Measurements. — Length of body: large male,
182 mm.; large female, 197 mm.

Color. — Body translucent, bluish white with
dusky bands and patches composed of scattered
black specks; rostrum and sides tinged with pink;
blades of pleopods marked with dark red ; anten-
nae dark brown ; uropods with tips of blades dark
brownish purple with narrow stripe of yellowish
green along margin.

Habitat. — Estuaries and inner oceanic littoral,
predominantly on mud bottom from water's edge
to 17 fathoms off Atlantic coast; rarely to 43
fathoms in Gulf of Mexico (Springer and Bullis,
1952).

Type locality.— Oft Matanzas Inlet, Fla.

Known range. — Fire Island, N.Y., to Cape Ca-
naveral, Fla.; Gulf of Mexico from Pensacola,
Fla., to Campeche, Mexico; Cuba; Jamaica.

Fiouke 8.— Penaeus setiferus (Linnaeus). Animal in lateral view; approximately 25 mm. indicated (after Rathbun,

1884).

FISH AND WILDLIFE SERVICE

Figure 9. — Penaeus setiferus (Linnaeus). Chroniato-
phore distribution in tail fan (seimdiagraniniatie) of A,
17 rum. juvenile, B, 32 mm. juvenile; A-B approximately
X 5 (after Williams, 1953). C, thelycum of adult fe-
male ; D, petasma of adult male, ventral view, distal
portion of left half (after Burkenroad, 1934b).

Remarks. — Of the shrimps occurring in the
Carolinas, P. setiferus has been studied most ex-
tensively. This has resulted from the fact that
the species has great commercial value, and was
the first of the American penaeids to be exten-
sively marketed for food. In the early 1930's,
when popular demand caused fishing effort to
expand greatly, concern over the possibility of
depleting the resource led the U.S. Fish and Wild-
life Service to initiate a research program on
various aspects of the biology of this species. At
that time, P. setiferus composed over 95 percent
of the commercial catch (Lindner and Anderson,
1956). A voluminous literature, scholarly and
popular, has accumulated in the ensuing 30 years,
and though it would be presumptuous to attempt
a complete review of this work here, the chief
results of studies can be outlined. (An exhaustive
bibliography has been complied by Chin and
Allen, 1959).

Recently (see synonymy) usage of the name
setiferus for the white shrimp in North America
has been questioned. The well-established name
setiferus would seem best, retained here.

The species is caught commercially throughout
most, of its geographic range (from North Caro-
lina to Mexico) ; however, by far the greatest
concentration occurs in Louisiana, in and near the
Mississippi River Delta, and it was here that
Viosca (1920) first wTorked on some aspects of
the species' natural history anticipating in many
respects later more detailed studies.

One of the latest studies to be published should
be cited at the outset. Young (1959) in his ex-
haustive morphological study of P. setiferus
reiterated the generalized structure of the
Penaeidae. This work is profusely illustrated and
the text illuminates details which have often been
obscurely presented in older works. Complexes
such as the branchial apparatus and associated
structures are clearly delineated, as are the
skeletal, muscular, nervous, circulatory, and res-
piratory systems in general. The genital armature,
of great taxonomic value, is treated briefly, and
here the student must look to the works of Burk-
enroad (1934b, 1939) for details.

In 1956, Lindner and Anderson summarized
work of the U.S. Bureau of Fisheries and the Fish
and Wildlife Service in the 1930's and 1940's that
had been presented in a series of shorter articles.
Reference to this paper will lead the reader to
earlier detailed studies.

Spawning of the white shrimp in the Carolinas
probably begins in May and extends into Septem-
ber (Lindner and Anderson, 1956; Williams,
1955a) ; farther south in the Gulf of Mexico the
season probably extends from March to September
or October. Gunter (1950) suggested two periods
of spawning (spring and fall) for Texas waters,
but in the Carolinas there is probably only one.

Maturation of gonads has been studied in de-
tail (King, 1948) in both males and females. In
females, the stages of maturity can be judged
macroscopically by color of the ovary. The earliest
or undeveloped stage may last for an indetermi-
nate period of time (Lindner and Anderson,
1956) ; the developing stage is judged to last a
month or less. The succeeding yellow stage per-
sists for 1 to 2 months, and the ripe, olive-drab
colored ovaries become spent in less than a month.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Spent ovaries were found to revert to the yellow
stage in a period of a few days and then to develop
toward a ripened stage again in 2 or 3 months.
A large female is estimated to produce a half
million to a million eggs at a single spawning
(Anderson, King, and Lindner, 1949).

It was thought that studies of the ovary would
lead not only to discovery of spawning grounds
but also to knowledge of how many times a female
shrimp might spawn, and to the approximate age
and length of life of the shrimp. Such hopes were
incompletely realized. The likelihood of multiple
spawning and absence of permanent scars or
walled-off areas in the ovary precluded aging by
this method. It is possible, but not proved, that
a shrimp can spawn more than once in a season.
Occurrence of ripe females suggests that spawn-
ing in Louisiana takes place offshore in depths
greater than 4.5 fathoms, probably between 5 and
17 fathoms. Heegaard (1953) reported occurrence
of spawning 6 or more miles from shore in from
10- to 15-fathom water in Texas. The exact loca-
tion of spawning grounds off the Carolinas re-
mains unknown.

Developmental stages of the white shrimp were
elaborated in detail by Pearson (1939), based on
plankton tows off the Mississippi River Delta and
the coasts of South Carolina, Georgia, and
Florida, and on rearing experiments with material
taken from plankton catches at St. Augustine
Inlet, Fla. (The eggs of penaeids are not carried
on the pleopods of the females as in other de-
capods, but are broadcast.) In this study, few
eggs were found, but this circumstance was at-
tributed to the fact that the eggs are demersal,
hence, hard to capture, and perhaps deposited
chiefly beyond the area sampled. Of the material
available for rearing, 5 of 15 eggs hatched within
24 hours after capture. Developmental stages
prior to hatching were described, and, following
hatching, five naupliar, three protozoeal, two
mysis, and a series of postlarval stages were de-
scribed. Pearson thought it likely that though
the larvae are more or less at the mercy of cur-
rents in the environment, they still are capable
of considerable independent movement. From the
spawning place at sea, a great number of the
larvae move inshore and enter estuaries at about
the second postlarval stage (7 mm. total length),
and it is at this stage that they abandon planktonic

for a benthonic existence. The length of larval
existence from time of hatching to entrance into
estuaries was judged to be about 2 or 3 weeks.

Heegaard (1953), studying wild populations of
larval white shrimp, and Johnson and Fielding
(1956), studying populations reared in captivity,
gave somewhat different interpretations of this
portion of development. Heegaard suggested that
the number of molts in certain portions of the
larval history may vary individually; Johnson
and Fielding, while agreeing with Pearson's
descriptions of stages, gave evidence for shorter
time of development from hatching to first post-
larva (about 2 weeks). They also gave evidence
for very rapid growth of the young, 2.1 mm. and
1.7 mm. per day in different experiments under
conditions of full feed. The same authors secured
good growth in both high and medium salinities.

Bearden (1961) demonstrated that postlarval
P. setiferus enter South Carolina sounds from
June through September, a period similar to the
supposed recruitment period in North Carolina
(Williams, 1959).

Once in estuaries on so-called "nursery grounds"
the young grow rapidly. Williams (1955a) esti-
mated an average increase in length of 36 mm.
per month (1.2 mm. per day), and other estimates
of similar nature have been made (Gunter, 1956;
Loesch, 1957). The young, which in the early
part of their benthonic existence tend to seek the
fresher, shallower portions of estuaries, move
gradually into deeper, saltier water as they grow,
and with approaching maturity they return to
sea. Hoese (1960) suggested that migration to
estuarine nursery grounds may not be essential
to development in this species, but Gunter (1961)
gave much evidence to the contrary. Most of the
individuals that grow to maturity appear to live
a year or a little longer. Some exceptional in-
dividuals in the deeper portion of the range may
live to be about 2 years old. Mature females at-
tain a larger size than mature males. Lindner
and Anderson (1956) estimated that mature P.
setiferus grow at a rate of about 20 mm. per month
during the period March to October.

In addition to annual cyclic movements of
larvae into estuaries, and subsequent movement
of subadults back to sea, tagging experiments have
indicated that P. setiferus may make coastwise
migrations of considerable length. In their ana-

FISH AND WILDLIFE SERVICE

lysis of these experiments, Lindner and Ander-
son (1956) showed that in fall and winter, shrimp
tend to move south along the Atlantic coast; in
late winter and early spring, there is a return
movement ; and during late spring and summer,
position of the population is relatively static.
Large individuals are prone to move longer dis-
tances than small shrimp. The longest recorded
southward movement was by a shrimp tagged at
Beaufort, N.C., in October, and recovered 95 days
later off Florida, 360 miles from the point of re-
lease. The greatest counter movement was from
Cape Canaveral, Fla., in January, to South Caro-
lina 168 days later, a distance of 260 miles.

Distribution of P. setifems is not uniform, and
this may be conditioned by a number of factors.
These are usually thought to be salinity, tempera-
ture, and substrate. The young may utilize waters
of somewhat lower salinity than the young of
related penaeids (Burkenroad, 1934b; Williams,
1955a). Hildebrand and Gunter (1953) and
Gunter and Hildebrand (1954) demonstrated a
strong positive correlation between the white
shrimp catch for a given year and total rainfall
for that year and the 2 preceding years in Texas,
high rainfall being followed by good catches. In
colder portions of the year no young are found in
inside waters, at least in the Carolinas (Williams,
1955a). Penaeus setiferus is usually found on a
muddy substrate on trawling and nursery grounds
(Springer and Bullis, 1954; Hildebrand, 1954,
1955), and in experimental tanks it has been
shown to choose muddy substrates in preference
to sandy or rocky bottoms even though it burrows

to a lesser extent than its near relatives (Williams,
1958).

In recent years the subadult populations of
white and other penaeid shrimp in estuaries have
been exploited for fish bait. Studies of such fish-
eries have given more detail on migrations and
density of population (Loesch, 1957) and on
individual length-weight relationships (Chin,
1960).

Penaeus duorarum Burkenroad. Pink, spotted, brown
spotted, or grooved shrimp

Figures 10-11

Penaeus brasiliensis: Hay and Shore [In part], 1918, p. 377,
pi. 25, fig. 6.

Penaeus duorarum Burkenroad, 1939, p. 31, figs. 18, 19, 23,
25-27 (rev.).

Recognition characters. — Integument thin, pol-
ished, translucent. Carapace with a median carina
continuous anteriorly with rostrum and extending
nearly to posterior border of carapace, flanked on
each side by a broad, rounded groove; posterior
half of carina with a median longitudinal groove ;
anterior half arcuate, highest above orbit and with
9 or 10 sharp teeth ; posterior tooth remote from
others, anterior 6 or 7 on rostrum proper. Lower
margin of rostrum wth two to three teeth (oc-
casionally one) ; tip slender, horizontal or directed
slightly downward, unarmed. Anterior margin of
carapace with strong antennal spine on carina
extending backward nearly to well-developed
hepatic spine. Cervical groove extending halfway
from hepatic spine to dorsal carina. A subhori-
zontal suture below hepatic spine, and a groove
extending from near hepatic spine to near base of
ocular peduncle. An orbital ridge behind eye.

Figure 10. — Penaeus duorarum Burkenroad. Animal in lateral view with part of appendages removed, "Form A"

from North Carolina ; natural size.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 0-^65 3

Figure 11. — Penaeua duorarum Burkenroad. A, carapace
and eyes of animal in dorsal view, "Form A" from
Xorth Carolina, natural size; B, petasma of adult male,
distal portion, view from right side ; C, thelycum of
adult female; B-C, 1 mm. indicated (after Burkenroad,
1039). Chromatophore distribution in tail fan (semi-
diagrammatic) of D, 17 mm. juvenile, E, 32 mm.
juvenile: D-E, approximately X .", (after Williams,
1953).

Female with thelycum composed of two broad
lateral plates, and a median plate. Posteromedian
part of median plate of adult with a well-
developed, short, longitudinal carina extending
anteriorly toward roughly semicircular, concave
anterior portion. Lateral plates produced medially
to meet in midline, except variably divergent at
anteromedian corners, thus exposing carina of
median plate.

Abdomen with segments four to six carinate,
carina of sixth ending posteriorly in a spine ami
Hanked on each side by a narrow groove. Telson
with deep median groove and an acuminate tip.

Petasma of male with distal ends of distoventral
lobes curved medially, not projecting free of dis-
tolateral lobes; external edge of distoventral lobes
with a series of 2 to 12, usually 4 to 7, small
spinules; median or attached edge of distoventral
lobes with a compact group of 6 to 16 large, long,
sharp, curved spines; fold of distolateral lobe
rather small and armed inconspicuously if at all.

Measurements. — Length of body : large male,
167 mm.; large female, 210 mm.

Variations. — Burkenroad (1939) divided the
species into two "Forms," "A" and "B."

In "Form A" the dorsolateral grooves of the
sixth abdominal segment usually are almost or
entirely closed, though they may be open to a
width of one-third the distance from their dorsal
lip to the midline.

In "Form B" the dorsolateral grooves of the
sixth abdominal segment are broadly open, their
width being from one-half to more than equal the
distance from their dorsal lip to the midline.

The rostrum is relatively shorter and deeper
in old individuals than in young ones. It extends
to the end of the basal antennular article in
average-sized adults. The rostrum in P. duorarum
is less sinuous and slender than in P. aztecus.

Color. — Juveniles and young adults from estu-
aries or oceanic water near shore are usually gray,
reddish brown or bluish gray of various shades,
with a more or less distinct spot of darker color
at the pleural juncture of the third and fourth
abdominal segments. In juveniles or young adults,
this spot and other bandings may be graj', blue
gray, blue, or purplish. The tail fan is nearly
transparent and edged with blue. In older in-
dividuals, especially from deeper oceanic water,
the colors tend to be red, pinkish-, blue gray or
nearly white. The abdominal spots are usually
red (Broad, 1950) or lacking entirely. Detailed
coloration of the young has been given by Wil-
liams (1953).

Habitat. — Estuaries and inner oceanic littoral,
predominantly on sand, shell-sand or coral-mud
bottom from water's edge to 28 fathoms; rarely
40 to 200 fathoms (U.S. Fish and Wildlife Serv-
ice, 1960).

Type locality. — Off Alabama [Atlantis station
2813, roughly lat. 30° N. long. 88° W.), 19
fathoms.

FISH AND WILDLIFE SERVICE

Known range. — Chesapeake Bay through Gulf
of Mexico and West Indies to Brazil ; Bermuda ;
West Africa, from Mauritania to Angola.

"Form A," Chesapeake Bay to Campeche, Mexi-
co; Bermuda. "Form B," Cuba through West
Indies to Brazil ; West Africa.

Remarks. — Penaeus duorarum, one of the west-
ern Atlantic littoral penaeids extensively utilized
for food, is caught in commercial quantities
throughout much of its geographic range (North
Carolina to Nicaragua and perhaps Brazil (Lind-
ner, 1957) ) . Distribution of this species is by no
means uniform, consequently the fisheries are con-
centrated at diverse points, some of these being
North Carolina, Key West, Fla., and Campeche
Banks, Mexico, with the latter two being by far
the largest. At other points in the range, the
species is not abundant enough to support a fishery
worthy of note.

A number of recent studies, especially in
Florida, have greatly enhanced our knowledge of
this species but only a brief summary is appropri-
ate here.

In North Carolina, roe-bearing females and
mature males appear in commercial catches from
the ocean near Beaufort. Inlet in May (Broad,
1950; Burkenroad, 1949; Williams, 1955a) and
they continue to occur into July. Mature ovaries
are blue-green in color. One spawning season a
year is indicated for this, the northernmost breed-
ing population of the species. There is strong
evidence, that this population is endemic.

In Florida, Cummings (1961) found stages of
maturation in the ovaries of P. duorarum females
similar to those in P. Setiferus; i.e., the ovary pass-
ing through a flaccid undeveloped stage, a de-
veloping stage containing larger ova, a nearly ripe
stage in which the ovary is large, visible from the
outside and glaucous in color, and a ripe stage in
which the ova contain characteristic rodlike re-
fractive bodies, and finally a difficult -to-determine
spent stage. The highest rate of spawning was
judged to extend from April through July, a
period comparable to that in North Carolina, but
ripe and nearly ripe females were found at other
times of year as well (see also Eldred, Ingle,
Woodburn, Hutton, and Jones, 1961). Cummings
indicated that multiple spawning probably occurs.
Eldred, Ingle, Woodburn, Hutton, and Jones
(1961) postulated that mating behavior is possibly

related to migratory behavior and that spawning
is initiated at minimal bottom temperatures of
23.9° C. (see also Cummings, 1961). They sug-
gested that annual temperature ranges within cer-
tain poorly understood, but not fatal, limits may
have a controlling influence on population size in
the following year.

The egg and larval stages of P. duorarum were
described in detail by Dobkin (1961) from ma-
terial taken from the Dry Tortugas fishing
grounds. Viable, yellow brown, opaque eggs,
0.31-0.33 mm. in diameter, were obtained from
mature females spawning in the laboratory. The
act of hatching required 2 to 3 minutes. Dobkin
described five naupliar, three protozoeal, three
mysis, and a number of postlarval stages. The
naupliar and first protozoeal stages were reared
in aquaria, but remaining stages were taken from
plankton.

Post larvae of P. duorarum have been distin-
guished from those of P. aztecus by Williams
(1959), and more fully described by Dobkin
(1961). The recruitment period in North Caro-
lina, extending from late May to November, agrees
well with the occurrence of ripe adults in the fish-
ery prior to and during the early part of this
period, and it also suggests that movement and
development time of larvae is about the same as
that found in P. setiferus (i.e., 2 or 3 weeks).
Bearden (1961) found a few postlarval P. duor-
arum from May through September in South
Carolina.

Once on the nursery grounds in estuaries, the
young undergo rapid growth. Williams (1955a)
estimated an average increase in length of young
shrimp at 52 mm. per month (about 1.8 mm. per
day) for warmer months. More recent work shows
that this estimate may be too high. Eldred, Ingle,
Woodburn, Hutton, and Jones (1961) found that
pink shrimp spawned in late March or April
could reach lengths of 45-65 mm. by July, while
those spawned in May could reach lengths of
25-35 mm. by July. Iversen and Jones (1961)
showed that a 103-mm. shrimp will grow 7 mm.,
a 130-mm. shrimp will grow 5 mm., and a 153-mm.
shrimp will grow little or none in a month in
either summer or winter. Eldred, Ingle, Wood-
burn, Hutton, and Jones (1961) estimated that
a 140-mm. shrimp is about 1 year old and that
on such basis shrimp measuring 200 mm. in

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

length are approximately 2 years old. Most in-
dividuals that grow to maturity live a year or
longer. Adult females attain a larger size than
adult males (various authors).

The young shrimp tend to seek shallower, often
somewhat fresher, portions of the estuaries in the
early part of their benthonic existence, and with
increasing size move gradually into deeper, saltier
water as they grow; finally, with approaching
maturity they return to sea. This general pattern
of movement may best be taken as a model which
is variously complicated in different parts of the
species' range. In North Carolina, and perhaps
elsewhere (Iversen and Idyll, 1960; Eldred, Ingle,
Woodburn, Hutton, and Jones, 1961) many of the
juveniles present in the sounds in fall do not
return immediately to sea but linger in the estu-
aries over winter. Here they are often subjected
to quite low temperatures (4° C.) and in severe
winters nearly all of this overwintering popula-
tion may be killed. Normally they survive the
winter, but because they are relatively inactive in
the cold, they grow little, at least in North Caro-
lina (November-April estimated average increase
in length, 7.5 mm. per month). Rising springtime
temperatures induce increased activity and feed-
ing, resulting in resumption of rapid growth and
an ensuing spring migration to sea in May and
June. In North Carolina, this migrating popula-
tion is large enough to create a sizable late spring
fishery.

In Texas (Hildebrand, 1955) and Florida
(Higman, 1952) young of P. duorarum are espe-
cially abundant in grassy areas of estuaries where
salinities are 20°/oo or more. This is true of
some areas in North Carolina, and the young are
also concentrated most heavily in areas where
there is a possibility of tidal transport (Williams,
1955b).

Tagging experiments to determine movements
of this species have been restricted to waters off
southern Florida. Iversen and Idyll (1960) and
Iversen and Jones (1961) demonstrated a general
northwestward movement for shrimp tagged on
the fishing grounds west of Key West and sug-
gested that small shrimp move from shallow water
at the end of the Florida peninsula to the Tortugas
fishing grounds.

Distribution of P. duorarum may be limited by
the same factors that influence P. setiferus; i.e.,

salinity, temperature, and substrate. Hildebrand
(1954, 1955) and Springer and Bullis (1954)
emphasized the fact that P. duorarum, fisheries I
are located in areas where the bottom is composed I
of calcareous muds and sands or mixtures of mud |
and sand. (This species usually burrows in the
substrate in the daytime and is most active at
night (various authors).) Laboratory experiments
have shown that subadult P. duorarum, when al-
lowed a free choice of sand, shell-sand, loose peat,
muddy sand or sandy mud, tend to choose shell-
sand with a somewhat lower preference for loose
peat (Williams, 1958). In shell-sand the animals
were often completely buried, and could be ob-
served only after being dug out. The experiments
confirmed observations on the correlation of loca-
tion of fisheries with bottom type in the Gulf
of Mexico and in North Carolina.

The fact that P. duorarum, alone, of the three
commercially abundant species of shrimps, is able
to overwinter in estuaries in the northern part of
its breeding range has suggested that it is better
able to withstand a combination of low salinity
and temperatures because of superior osmoregu-
latory abilities at low temperature. Preliminary
studies have shown that P. duorarum is better able
to regulate its internal fluids at low temperatures
than its close relative P. aztecus, but regulatory
ability of both species is impaired when tempera-
tures are lowered to about 8° C, and survival
of both species is better in moderate to high
salinities at low temperatures (Williams, 1960).
Eldred, Ingle, Woodburn, Hutton, and Jones
(1961) considered that the depth to which the
species may burrow in cold weather (6 inches)
may protect it from sudden cold snaps.

Penaeus aztecus Ives. Brown or grooved shrimp

Figure 12

Penaeus trasiliensis aztecus Ives [In part], 1S91, p. 190.
Penaeus brasiliensis: Hay and Shore [In part], 1918, p. 377.
Penaeus aztecus: Burkenroad, 1939. p. 34, figs. 20, 21, 24,
28-33 (rev.).

Recognition characters. — Integument thin, pol-
ished, translucent. Carapace with a median ca-
rina continuous anteriorly with rostum and
extending nearly to posterior border of carapace,
flanked on each side by a broad, rounded groove ;
posterior half of carina with a median longi-
tudinal groove; anterior half arcuate, highest
above orbit and with 9 or 10 sharp teeth; pos-

FISH AND WILDLIFE SERVICE

Figure 12. — Penaeus aztecus Ives. A, anterior portion of
animal in lateral view, "Form A" from North Carolina,
natural size: B, petasma of adult male, distal portion,
view from right side ; C, thelycum of adult female ; B-C,
1 mm. indicated (after Burkenroad, 1939). Chromato-
phore distribution in tail fan (semidiagrammatic) of
D, 17 mm. juvenile, E. 32 mm. juvenile; D-E, approxi-
mately X 5 (after Williams, 1953).

terior tooth remote from others, anterior 6 or
7 on rostrum proper. Lower margin of rostrum
with two or three teeth, tip slender, horizontal,
or directed slightly upward, unarmed. Anterior
margin of carapace with strong antennal spine
on carina extending backward nearly to well-
developed hepatic spine. Cervical groove extending
halfway from hepatic spine to dorsal carina. A
subhorizontal suture below hepatic spine, and a
groove extending from near hepatic spine to near
base of ocular peduncle. An orbital ridge be-
hind eye.

Female with thelycum composed of two broad
lateral plates and a median plate. Posteromedian
part of median plate variably ovate-acuminate in

outline with tip raised into a short posterior carina
diverging anteriorly into raised margins. Ventral
surface concave; broad anterior end of posterior
part merging into concave, triangular or semi-
circular anterior portion. Lateral plates produced
medially to meet in midline except diverging to ex-
pose median plate.

Abdomen with segments four to six carinate,
carina of sixth flanked on each side by a narrow
groove. Telson with deep median groove and an
acuminate tip. Petasma of male with distoven-
fcral lobes not projecting free of distolateral lobes ;
with several compact series of short, crowded
spines near distal ends; a fold of free margin
of distolateral lobe beyond end of distoventral
lobe bearing moderate spinose armature.

Measurements. — Length of body: large male,
162 mm.; large female, 211 mm.

Variations. — Burkenroad (1939) divided this
species into "Forms," "A," "B," and "C." The
chief differences are summarized here.

In "Form A," the grooves lateral to the dorsal
carina are well denned posteriorly and are dis-
tinctly broader than the carina. The carina is
distinctly and continuously grooved. The dorso-
lateral grooves of the sixth abdominal segment
are broadly open, their width "being from three-
fourths to equal the interval between their dorsal
lip and the midline."

In "Form B," the grooves lateral to the dorsal
carina are usually much narrower than the carina
and tend to be ill defined posteriorly. The dorso-
lateral grooves of the sixth abdominal segment
"range up to one-half as broad as the interval
between their dorsal lip and the midline, and
the dorsal lip is frequently low and ill denned."

In "Form C," the grooves lateral to the dorsal
carina are much as in "Form A," but the carinal
groove is shallow and frequently interrupted by
plane intervals. The dorsolateral grooves of the
sixth abdominal segment are extremely narrow,
"their width less than a third of the interval
between their dorsal lip and the midline, and are
sometimes entirely closed."

The rostrum is relatively shorter and deeper in
old individuals than in young ones. In unworn
adults, it reaches to or beyond the middle of the
third antennular article. In young adults, it may
reach the end of the antennal scale. The rostrum

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

in P. aztecus is more sinuous and slender than
in P. duorarum.

Color. — Juveniles and young adults from
estuaries or oceanic water near shore are usually
brown or grayish brown, occasionally with darker
spots or faint concentrations of chromatophores
at the pleural articulations. Individuals from
deeper water are light orange (Burkenroad, 1939) .
The tail fan is darkened distally and in adults is
edged with purple to reddish purple. Detailed
coloration of the young has been given by Wil-
liams (1953).

Habitat. — Estuarine and oceanic littoral, pre-
dominantly on mud bottom from water's edge
to 45 fathoms; rarely to 89 fathoms.

Type locality. — Veracruz, Mexico.

Known range. — New Jersey (occasionally to
Marthas Vineyard, Mass.) through Gulf of
Mexico and West Indies to Uruguay.

"Form A," New Jersey to Campeche, Mexico.

"Form B," Florida through West Indies;
Panama to Rio de Janeiro, Brazil.

"Form C," Pernambuco, Brazil, to Montevideo,
Uruguay.

Remarks. — Penaeus aztecus, the third of the
littoral penaeids abundant enough to be utilized
profitably for food, is also fished commercially
throughout much of its range (North Carolina
to Brazil), and total landings for this species now
outstrip the other two combined. When the U.S.
Bureau of Fisheries began research on the natural
history of P. setiferus in the 1930's, few grooved
shrimp were sold, but with the advent of increased
market, larger trawlers, and discovery of large
concentrations of both P. duorarum and P. aztecus
in different localities than had formerly been
fished, the latter species were extensively utilized.
Conversely, in recent years it is also possible that
there has been a decline in abundance of P. setif-
erus throughout much of its range (various
authors). Tremendous quantities of P. aztecus
are now landed in the western Gulf of Mexico.

Prior to Burkenroad's revision (1939) of the
grooved shrimps of the western Atlantic, three
currently recognized species were lumped under
the name P. brasiliensis. Biological data taken
prior to that time on these species, never so ex-
tensive as those for P. setiferus, cannot now be
assigned with certainty to any single species.

However, taking into consideration the locations
where research was done, as well as modern
knowledge of species distributions, it is probable
that most of those data on grooved shrimps apply
to P. aztecus (see also Pearson, 1939).

Maturation of gonads in P. aztecus probably
parallels the process as understood in P. setiferus,
although few data are recorded on this subject.
Broad (1950) described maturing ovaries found
in August as opaque white, yellow, tan, or
gray in color. Burkenroad (1939), working in
Louisiana, noted that whereas the proportion of
males to females in P. aztecus near shore was
about 1 to 1, this ratio progressively changed in
samples farther from shore, in deeper water, to
a ratio of 1 to 2 in water 50-70 fathoms deep.
Moreover, the females in deep water were much
larger than the males, a characteristic shown also
by the related P. setiferus and P. duorarum and
young adult populations of all three species in-
shore. Burkenroad attributed the size disparity
of these large offshore individuals to greater
length of life among females. Knowledge that
impregnated females occurred only beyond 10
fathoms, together with the fact that mature (and
possibly spent) ovaries <were found only in indi-
viduals beyond these depths at various times of
year, led him to propose that the females spawned
a number of times during an ill-defined spawning
season.

Williams (1959) favorably assessed Pearson's
(1939) determination of P. brasiliensis (unfor-
tunately misspelled "braziliensis" in Williams) as
most probably P. aztecus, and proceeding on the
basis of Pearson's distinguishing characters was
able to separate P. duorarwm and P. aztecus post-
larvae in the plankton in North Carolina. Post-
larvae of the latter were found entering the
sounds from October to May, with peak recruit-
ment from late March to early April. Bearden
(1961) found peak recruitment to occur in Febru-
ary and March in South Carolina. These patterns
agreed well with collections of juveniles (Wil-
liams, 1955a) in which recruitment began in
mid-April and continued through the summer.
A long winter spawning season supplies post-
larvae to the Carolina sounds, but fall and mid-
winter recruits are apparently killed by cold
weather for they never progress beyond postlarvae

FISH AND WILDLIFE SERVICE

iii the samples taken. Pearson found postlarvae
in Louisiana in all months of the year, but in no
more than 11 months of any calendar year. The
usual recruitment period seemed to run from late
January to late summer.

Gunter (1950) found young brown shrimp in
Texas bays most common in spring and fall with
low abundance in late summer and winter.

Evidence indicates that P. aztecus has an ex-
tended spawning season which probably varies in
different parts of the range. The spawning site
is probably deeper and farther from shore than
in P. setiferus and P. duorarum.

Young P. aztecus enter estuaries as postlarvae,
migrate to shallow, often low-salinity water, and
undergo a remarkably rapid growth in the warmer
months. In North Carolina, the juveniles in-
crease in mean length by an estimated 46 mm.
per month (1.5 mm. per day, Williams, 1955a).
As they grow, they gradually move to deeper,
saltier water and eventually return to sea. In
North Carolina, and perhaps elsewhere, P.
duorarum and P. aztecus use essentially the same
nursery grounds over large areas of the sounds;
however, the seasons of recruitment to and oc-
cupation of these areas is staggered in such a
manner that the two species are rarely on common
ground (Williams, 1955a, b). The growing bait
fisheries for estuarine shrimp in recent years
have given impetus to studies in Alabama and
Texas. Additional information on migration
(Loesch, 1957) and studies on length-weight re-
lationships (Chin, 1960) have resulted from this
work.

Again, distribution of P. aztecus is usually
thought of as limited by such factors as salinity,
temperature, and substrate. Hildebrand (1954,
1955) and Springer and Bullis (1954) stated that
the commercial fishery for this species in the
Gulf of Mexico was confined largely to bottoms
of terrigenous silt. (Like P. duorarum, P.
aztecus is a burrower, and in many areas is more
active in open water at night than in daytime.)
In experimental tanks, when given a choice of
sand, shell-sand, loose peat, muddy sand and
sandy mud, P. aztecus was found to favor loose
peat, sandy mud and muddy sand, closely paral-
leling P. setiferus in choice of bottom type (Wil-
liams, 1958). The experiments confirm field ob-

servations on habitat along the coast of North
Carolina and in the Gulf of Mexico.

Penaeus aztecus has been found to have a less
efficient osmoregulatory mechanism at low tem-
peratures in low salinities than P. duorarum
(Williams, 1960). For this reason, it is probably
not so resistant to wintertime conditions in
estuaries as P. duorarum.

Genus Parapenaeus Smith, 1886

Burkenroad, 1934b, p. 107.

Parapenaeus longirostris (Lucas)

Figures 13-15

Pencils longirostris Lucas, 1849, p. 46, pi. 4, fig. 6.
Parapenaeus politus: Hay and Shore, 1.918, p. 379, pi. 2.r>. fig. 7.
Parapenaeus longirostris: Burkenroad, 1934b, p. 108 (rev.). —
1939, p. 53.

Recognition characters. — Integument smooth,
not setose. Carapace with a low carina extending
almost to posterior margin and bearing a spine
some distance behind rostrum. Rostrum arched;
distal half deflexed, tip somewhat upturned, ex-
tending to or bej'ond distal edge of eye; dorsal
margin with usually seven teeth diminishing in
size anteriorly; ventral margin heavily ciliated.
Hepatic, antennal, and branchiostegal spines well
developed; later spine placed a little behind
margin of carapace. A rectangular toothlike
eminence at orbital angle. A shallow groove ex-
tending from behind eye almost to posterior edge
of carapace, and another, extremely faint, run-
ning upward from inferior margin at base of
second pair of legs. Basal antennular article
with a spine on ventromedial! margin distally.

Thelycum of female composed externally of a
triangular plate with obtuse apex on 13th somite
(base of 4th leg) ; 14th sternite raised anteriorly,
with low relief posteriorly; lateral ridges with
nearly straight but divergent medial borders
separated by nearly plane, broad medial groove;
lateral border of ridges ornately curved to fit
contour of adjacent coxae and 13th sternite.

Figure 13. — Parapenaeus longirostris (Lucas). Anterior
portion of animal in lateral view, X 3.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

A B

Figure 14. — Parapenaeus longirostris (Lucas). Petasma
of male, A, ventral view; B, sternal view (after Heldt,
1938).

Figure 15. — Parapenaeus longirostris (Lucas). Thelyeuin
of female; A, external plate of somite 13; B, internal
structure showing sacs extending into somite 14 (after
Heldt, 1938).

Petasma of male with each half terminating in a
dorsomedian spinelike projection with a fleshy
distomedian lobe at base; proximal to latter, a
broad lateral spine with a fleshy distolateral lobe
at base continuous with distomedian lobe but not
projected laterally as a spoutlike horn as in
Xiphopeneus ; finally, still further proximally a
spinelike distoventral projection partially covered
by a medial distoventral flap.

Abdomen with fourth, fifth, and sixth segments
(•annate, carina ending on each segment in a small
tooth. Sixth segment a little more than twice
length of fifth. Telson tapering to a sharp point,
furrowed above, with a slender spine on each side
near tip.

Measurements. — Western Atlantic population: '
length of body, 104 mm. Mediterranean popula-
tion: length of body, 165 mm.

Variations. — European examples of the species I
attain a greater size than do American forms. The
length of the rostrum varies with age, becoming I
relatively longer with variable development of !
an unarmed tip in large individuals. The sixth
abdominal segment is relatively shorter in large
than in small individuals.

Color. — Eyes green; body and appendages mot-
tled with red and pale translucent areas; uropods I
with exopod and distal half of endopod deep red
(Burkenroad, 1934b).

Habitat. — Soft mud or muddy sand bottom
(Heldt, 1954) ; 15 to 180 fathoms or more in
western Atlantic (Burkenroad, 1934b, 1939) ; 20
to 250 fathoms in Mediterranean (Heldt, 1954,
1955).

Type locality. — Algiers and Cap-Matifou,
Algeria.

Knoxon range. — Marthas Vineyard, Mass., to
Gulf of Mexico off Florida, Louisiana, and Yuca-
tan; Gulf of Paria off Venezuela; coast of
Portugal to Morocco; Mediterranean Sea from
Spain to Asia Minor.

Remarks. — Though this species occurs on both
sides of the Atlantic, it has been studied in detail
chiefly in the European portion of its range. The
European population is composed of larger in-
dividuals than the American population (Burken-
road, 1934b) and because of its size and abun-
dance is commercially exploited off the coast of
Tunisia (Heldt, 1954). The American population
is also quite abundant in the northern Gulf of
Mexico (Burkenroad, 1939).

It is possible that this species lives beyond the
100-fathom depth off the Carolinas, but because
it is known to move into shallower water in parts
of its range it is included here. Heldt (1938)
stated that the depth distribution starts at about
30 fathoms, but usually extends from 55 to 200
and more fathoms. She described characteristic
features of what she termed the "fonds a Para-
penaeus" in the Mediterranean Sea (1954).

The developmental stages of this species have
been treated in detail by Heldt (1938) from the
Mediterranean and in somewhat lesser detail by
Pearson (1939) from the northern Gulf of Mexico.

FISH AND WILDLIFE SERVICE

Heldt described cleavage stages of the egg, for-
mation of the embryo, 8 naupliar, 3 protozoeal,
14 mysis stages, and the first postlarval stage.
Pearson found protozoeal, mysis, and postlarval
stages principally during July off South West
Pass, La. ; and usually a complete set of larval
stages was taken in a single plankton collection.
A single mysis was taken south of Barataria Pass,
La., in May and a single first protozoea at Fort
Pierce, Fla., in January.

Genus Penaeopsis Bate, 1881

Bate, 1881, p. 182.

Penaeopsis goodei (Smith)

Figures 16-17

Parapenaeus goodei Smith, 1885, p. 176.

Penaeopsis goodei: Verrill, 1922, p. 44, pi. 15, figs. lA-lAiv ;

pi. 16, fig. 3. — Burkenroad, 1934a, p. 15, figs. 2, 3 (rev.).

Recognition characters. — Carapace and abdo-
men covered with rather stiff, plumose hairs.
Carapace about as wide as deep and very little
compressed anteriorly. Rostrum rising obliquely
above level of dorsum, shorter than carapace
proper and armed above with 8 to 10 teeth in
front of orbital margin; a sharp gastric tooth
behind rostral carina. Antennal, hepatic, and
branchiostegal spines well developed; a rec-
tangular toothlike eminence at orbital angle;
grooves inconspicuous. Eyes large, reniform,
flattened above. Antennular flagella subequal in
length and about as long as second article of
peduncle. Antennal scale reaching to tip of
antennular peduncle; distal portion of thickened
outer margin armed above with series of minute
spines directed obliquely forward and outward.

Third maxilliped, first and second legs armed
with basal spines. A small distal spine on ventral
side of ischium of first leg. A pair of long, slen-
der spines arising from sternum between second
legs.

Figure 16. — Penaeopsis goodei (Smith). Anterior por-
tion of animal in lateral view.

Figure 17. — Penaeopsis goodei (Smith). A, petasma of
male in ventral view, approximately X 9-5 ; B, petasma
in ventral view, distal portion with right external piece
removed, approximately X 1-t (after Bnrkenroad,
1034a).

Thelycumof female composed of an anterior flat-
tened oval portion with a slender anterior median
spine on 13th somite (between 4th leg), and a short
broad, posterior portion on 14th somite connected
to preceding structure by a less elevated median
prominence flanked by an irregular bulbous en-
largement on each side. Petasma of male exceed-
ingly complicated and asymmetrical; left side
irregularly folded longitudinally, projecting
proximally in a curved process beyond right half
and to right of median line, and extending dis-
tally in an irregular process; right side enlarged
distally and divided into several irregularly
curved processes projecting beyond left appen-
dage, and partially covered posteriorly by a thin
spoon-shaped lamella arising at their bases.

Abdomen with third to sixth segments carinate
dorsally ; carina of fourth and fifth narrowly cleft
at posterior margin. Telson considerably longer
than sixth segment; rounded and obscurely
grooved above; regularly tapered; armed with a
long spiniform process at each side of acute tip,
and three pairs of movably articulated spines in
front of lateral spines, posterior ones largest.

Measurements. — Length of carapace including
rostrum : male, 19 mm. ; female, 21 mm.

Habitat. — Surface to 180 fathoms.

Type locality. — Bermuda.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Known range. — Between Capes Hatteras and
Lookout, N.C., through Caribbean Sea and "West
Indies to Surinam ; Bermuda.

Remarks. — Larval stages from Bermuda that
probably belong to this species were described by
Gurney (1943b). From observations at Bermuda,
Wheeler (1937) described characteristic swarm-
ing of this species at about an hour after sunset,
with monthly maxima on the 2d and 26th days of
the lunar month.

Genus Xiphopeneus Smith, 1869

Burkenroad, 1934b, p. 102.

Xiphopeneus kroyeri (Heller)

Figures 18-20

Peneue kroyeri Heller, 1862, p. 425, fig. 51.

Xiphopeneus kroyeri: Burkenroad, 1934b, p. 103, flg. 12
(rev.). — Schmltt, 1935a, p. 132, fig. 5.— Holthuis, 1958, p. 70,
fig. 7.

Recognition characters. — Carapace and abdo-
men smooth. Rostrum laterally compressed,
sinuous, armed with usually five dorsal teeth at
base, styliform tip greatly elongated beyond
antennal scales and varyingly elevated. Carapace
with a single ejjigastric tooth behind rostral series
on rounded postrostral carina extending from base
of rostrum to near posterior border; no trans-
verse suture in adults; anterior cervical groove
reaching anterior margin and continuous with
branchiocardiac groove reaching almost to pos-
terior border; hepatic and antennal spines present.
Antennal flagella much longer than body ; anten-
nal scale extending beyond tip of antennular
peduncle. Inferior antennular flagellum up to 50
percent length of antenna. Exopodites of second
and third maxillipeds slender.

Last two pairs of legs elongate, flagelliform,
with dactyls many jointed.

Figure 18.- -Xiphopeneus kroyeri (Heller). Anterior
pail of animal in lateral view, approximately X 3.2
after Holthuis, 1959).

Figure 19. — Xiphopeneus kroyeri (Heller). Petasiua of
adult male, ventral view, 1 mm. indicated.

Figure 20. — Xiphopeneus
kroyeri (Heller). Thely-
cum of female, filled
sperm sacs showing
through abdominal in-
tegument (after Burken-
road. 1934b).

Fourth to sixth abdominal segments carinate,
with small dorsal tooth at posterior end of carina
on each segment; sixth segment with carina high
and deep. Telson tapering to acute tip.

Petasma of male with distolateral corners
greatly produced as hornlike projections, open
along distal margins on thoracic face. Thelycum
of female externally appearing as an unpaired
plate extending forward from last thoracic
somite.

Measurements. — Length of body : 127 mm.

Variations. — The rostrum is somewhat longer in
females than in males, and varies with age. In
individuals with carapace length under 9 mm.,
the rostrum is shorter than the carapace, but be-
yond this size it is usually longer than the
carapace.

Color. — Whitish, ventral part yellowish, occa-
sionally with yellow over whole body but most

FISH AND WILDLIFE SERVICE

distinct ventrally; dark chromatophoi-es scattered
throughout and when expanded giving animal a
grayish cast ; tips of rostrum and flagella reddish ;
legs pinkish or yellowish orange; pleopods and
uropods yellowish at base, pink distally; telson
and sixth abdominal segment sometimes pink
(Holthuis, 1959).

Habitat. — This species lives in a narrow zone
along shore, and at times in the lower portion of
estuaries (Gunter, 1950; Holthuis, 1959), from
2.5 to 20 fathoms, rarely to 24 fathoms (Burken-
road, 1939; Gunter, 1950).

Type locality. — Rio de Janeiro, Brazil.

Known range. — Between Capes Hatteras and
Lookout, N.C., through Gulf of Mexico and
Caribbean Sea to near Santos, Sao Paulo, Brazil ;
Pacific coast variety (X. riveti, see Burkenroad,
1934b) from Mexico to northern Peru.

Remarks. — This species is of commercial im-
portance in the southern United States (Wey-
mouth, Lindner, and Anderson, 1933 ; Hildebrand,
1954), and of great importance in South America
(Lindner, 1957; Higman, 1959), especially along
the northeast coast where it dominates the near-
shore fishery and the young dominate the coastal
nursery areas, perhaps offering serious competi-
tion to other penaeids.

No detailed study of the ecology of this species
has been made. Burkenroad (1949) observed ripe
or nearly ripe females off North Carolina in May,
and Gunter (1950) found them along the Texas
coast in June. Vieira (1947), in a study on
maturation, found mature females off Sao Paulo,
Brazil, from November to January.

Gunter (1950) studied a population ranging in
size from 28 to 127 mm. total length. He found
a population mode of 38 mm. total length in
October but no definite modes in other months.
The species was most abundant in fall. Gunter
pointed out that the species does not customarily
live in bays, even though it lives in shallow
water close to the Texas shore. The young may
enter the lower end of Texas bays (21.2-30.7
°/00), but most individuals were found in the
Gulf of Mexico in a salinity range of 29.7 to
35.2°/0o. Similar salinity tolerances were implied
by Lindner (1957) and noted by Holthuis (1959).
Though the South American shrimp are caught in
estuaries and rivers, the penetration into these
areas is greatest in dry seasons. Both Lindner

and Holthuis gave data on the fisheries and proc-
essing methods.

Genus Trachypeneus Alcock, 1901

Burkenroad, 1934b, p. 94.

Trachypeneus constrictus (Stimpson)

Figure 21

Penaeus constrictus Stimpson, 1871b, p. 135.
Trachypeneus constrictus: Hay and Shore, 1918, p. 378, pi.
25, fig. 9.— Schmitt, 1935a, p. 131.

Recognition characters. — Dorsal region of cara-
pace with fine, short, appressed setae; branchial
region of carapace and last two abdominal seg-
ments variably pubescent ; abdomen smooth proxi-
mally. Carapace carinate except for short stretch
near posterior border; a spine behind base of
rostrum; antennal and hepatic spines well de-
veloped; a rectangular toothlike eminence at
orbital angle; lateral groove extending about
three-fifths length of carapace; anterolateral
angle truncate. Rostrum reaching to about mid-
dle of second segment of antennal peduncle,
directed slightly upward; upper margin usually
slightly arched and bearing usually seven to nine
equidistant teeth diminishing in size toward tip.
Eyes large, reniform. Antennular peduncle pubes-
cent above, extending slightly beyond antennal
scale; flagella shorter than carapace. Third
maxilliped, first and second legs with basal spines.

Abdomen carinate from fourth to sixth segment.
Telson with two rounded carinae above ; tapering
to a short acuminate tip, armed on either side with
a short spine.

Figure 21. — Trachypeneus constrictus (Stimpson). Ani-
mal in lateral view, approximately X 1.5 (after Verrill,
1922).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Thelycum of female with anterior margin of
median plate and lips of transverse groove evenly
rounded, notched in middle; lateral flaps of last
thoracic somite overlapping median plate; rib
supporting expanded median plate extending
anteriorly and sharply set off from anterior ven-
tral margin of plate; ventral surfaces pubescent.
Sternal elevation between coxae of fifth leg of
male with lateral margins indented setting off
posterior portion from broad anterior basal por-
tion; petasma with distolateral corners greatly
produced as hornlike projections.

Measurements. — Length of body : 92 mm.

Color. — Translucent with purplish-gray
blotches ; appendages pink.

Habitat. — Primarily sand or mud and shell
bottom in high-salinity water; shallow water to
30 fathoms.

Type locality. — Beaufort, N.C.

Known range. — Tangier Sound, Chesapeake
Bay, to Texas; Bermuda; Puerto Rico and
Sombrero Island; Surinam.

Remarks. — Eldred (1959) reported T. con-
strictus as common in the Tortugas area of Florida
where, along with its near relative, T. similis, it
makes up about 7 percent of the annual commer-
( cial catch. It probably contributes more to catches
in deeper water than to catches in the area
sampled. Gunter (1950) stated that T . constrictus
was rarely taken in coastal bays of Texas,
being largely confined to water above 30°/oo.
In littoral waters, ripe females were taken in
September and small specimens (about 29 mm.
total length) in March.

Burkenroad (1939) remarked that T. con-
strictus might be restricted largely to sandy
bottom, and Hildebrand (1955) suggested a dis-
tribution possibly correlated with bottom type,
but did not specify the type.

The early developmental stages of T. constrictus
were treated by Pearson (1939). All larval and
postlarval stages were pieced together by success-
ful rearing techniques coupled with plankton
catches at St. Augustine Inlet, Fla. Descriptions
were given of the egg (from the two-cell stage
onward), five naupliar, three protozoeal, two
mysis, and early postlarval stages. A year-round
spawning season is indicated, because eggs were
taken at St. Augustine, Fla., from April to
August, and at Fort Pierce, Fla., in summer and

from December to February. Nauplii were found
from April to August, and the remaining stages
from May to August, with a few protozoeae being
taken also in winter. Pearson found develop-
mental stages of this species more abundant than
those of related species in shallow oceanic water;
in estuarine water the postlarvae were rare. He
attributed this rarity and the comparative scarcity
of adults in commercial catches to the burrowing
habits of postlarvae and adults, as observed in the
laboratory. Somewhat contrary to Pearson's find-
ings, the juvenile stages of this species have been
caught commonly in surface plankton tows made
with a coarse-mesh net on nightly flood tides in
Bogue Sound near Beaufort Inlet, N.C. These
collections have been made in summer and fall
(mid-June to mid-November) when salinities
ranged from 28 to 36 %0 .

Subfamily Sicyoninae

Body more or less sculptured and rigid, with
prominent, often more or less interrupted dorsal
carina. Carapace with or without spine at anten-
nal angle. Lateral section of ocular somite de-
veloped into elongated stylet. Basal antennular
article lacking enlarged ciliated protuberance
(prosartema) on inner proximal margin. No
pleurobranchs behind ninth somite (third maxil-
liped). Fourteenth somite (fifth legs) without
gills. Pleopods lacking endopods except in modi-
fied form on first and second j)leopods of male
( modified after Burkenroad, 1931b ) .

Burkenroad (1934b) pointed out that the sub-
family Sicyoninae is an extremely uniform group.
Unlike other penaeids, sexual maturity may be
attained at a quite small size. "Differences be-
tween small and large individuals of any species
are slight and chiefly affect rostral length, eleva-
tion and distal armature, these features in
general becoming respectively shorter, more
horizontal, and with more numerous distal teeth
as size increases, and the armature of the pleonic
[abdominal] pleura, which generally increases in
strength and extent with growth." The thelycum,
and corresponding male genital sternites, are less
varied than among other penaeid groups, and,
consequently, are not so serviceable in distinguish-
ing species. The serious student is referred to
Burkenroad (1934b, pp. 70-76) for full discussion
of these characters.

FISH AND WILDLIFE SERVICE

Genus Sicyonia Milne Edwards, 1830 by Burkenroad (1945) and Hall (1956). The

„ , . ia„. „„ ,Qjr „ . „„„ iaKfl „ a7 name Sicyonia H. Milne Edwards, 1830, has been

Burkenroad, 1934a, p. iO. — 1945, p. 1. — Hall, 19a6, p. 87. — J

Hemming, 1958b, p. 126. validated under Plenary Powers of the Inter-

The generic name Sicyonia has had a complex national Commission on Zoological Nomenclature
nomenclatural history, and was reviewed in detail (Opinion 382; Hemming, 1958b).

KEY TO SPECIES IN THE CAROLINAS

(Modified after Lunz, 1945)
a. Antennal angle not armed with a definite spine; ischium of first leg armed with a spine.

b. Rostrum (excluding tip) with two dorsal teeth before posterior margin of orbit; carina of carapace with three teeth ,

first tooth smallest ..laevigata (p. 33) .

bb. Rostrum (excluding tip) with three dorsal teeth; carina of carapace with three evenly spaced, subequa 1

teeth ..parri (p. 34).

aa. Antennal angle armed with definite spine (sometimes blunt); ischium of first leg unarmed.

b. Three or four teeth on carina of carapace behind orbital margin, three large; carina high; rostrum extending beyond

midpoint of cornea, with two dorsal teeth (excluding tip) - -brevirostris (p. 35).

bb. Two or three teeth on carina of carapace behind orbital margin, two large and behind hepatic spine; rostrum not

extending beyond midpoint of cornea, with one or two dorsal teeth (excluding tip) .... ..typica (p. 36).

bbb. Two teeth on carina of carapace behind orbital margin, one behind hepatic spine; rostrum with three dorsal
teeth (excluding tip),
c. Fourth abdominal segment with anterior and posterior ends of ventral margin of pleura spined or

angular,.-. ..dorsalis (p. 37).

cc. Fourth abdominal segment with posterior end of ventral margin of pleura rounded stimpsoni (p. 38).

Sicyonia laevigata Stimpson

Figures 22-23

Sici/onia laevigata Stimpson, 1871b, p. 131. — Hay and Shore,
1918, p. 379, pi. 25, fig. 1.

Euaicyonia laevigata: Burkenroad, 1934a, p. 76, figs. 21. 26,
32 (rev.).— Lunz, 1945, p. 4, fig. 1.

Recognition characters. — Integument rather
firm, finely granulate and more or less sculptured.
Rostrum elevated at angle of about 20 degrees,
about, half as long as carapace; armed dorsally
with two teeth not counting tip ; terminal portion
divided into four teeth; notch between median
pair shallower than dorsal and ventral notches;
often two short, stout, asymmetrically placed,
mobile spines distally above ventral margin.
Postrostral carina with three teeth behind orbital
margin; anterior one slightly advanced beyond
level of hepatic spine and about same size as
rostral teeth, often appearing as part of rostral
series; posterior two teeth closer together; carina
sometimes nearly obliterated anterior to each
tooth. Antennal angle unarmed but not rounded.
Ocular stylets short.

Abdominal segments marked by tergal carinae
deeply notched behind on first to fifth segments.
First abdominal segment with carina produced
into an elevated anterior tooth; marked laterally
by two grooves, a long posteromedian and short
anteromedian groove obliterated a short distance

Figure 22. — Sioyonia laevigata Stimpson. A, carapace
and first two abdominal segments in lateral view, ap-
proximately X 3 ; B. petasma of male In ventral view,
approximately X 20.5 (A-B after Burkenroad, 1934a 1.

ventral to juncture with anterior margin of
pleura but with short resumption below juncture.
Second and third segments with anterior and
short posterior tergal grooves; a short, shallow
anteromedian pleural and a posteromedian pleural
groove turning sharply anteriad somewhat above
middle of lateral surface. Second segment with
carina narrowly and deeply cleft above juncture
of tergal groove. Fourth and fifth segments with
posterior tergal groove, and an anterior groove, ob-
literated forinterval belowshort dorsal section;re-
appearing farther ventrad. Sixth segment with a
posteromedian pleural, anterior tergal and a longi-
tudinal groove; carina ending in a strong posterior
tooth. Ventral pleural margins rounded except
for a posterior tooth on fifth and sixth segments.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure 23. — Sicyonia laevigata Stimpson.
Thelycum of female, X 10.4 (after Bur-
kenroad, 1934a).

Telson ending in a strong point flanked by a pair
of shorter blunt spines ; sometimes with a pair of
mobile lateral spines distal to basal shoulders.

Petasma of male with distolateral projections
extending straight distally. Thelycum most con-
spicuously marked by elongate plate arising on
13th somite (between 4th legs), with slender tip
extending to level of 11th somite (2d legs).

Measurements.- — Length of body: males, 14
mm. ; females, 50 mm.

Variations. — The angle of elevation of the ros-
trum varies with age. Nearly horizontal among
the young, it rises to as much as 35 degrees in
older individuals. The usual angle is somewhat
in excess of 20 degrees. The number of carinal
teeth on the carapace may be reduced to two
(Lunz, 1945).

Color. — Yellowish brown ; carapace darker than
abdomen and sometimes bluish or greenish.

Habitat. — A littoral species fairly common in
the Carolinas, especially on shelly bottoms of
harbors; shallow water to 49 fathoms.

Type locality. — Charleston, S.C.

Known range. — Cape Hatteras, N.C., to north-
west Florida; through West Indies to Colombia;
Pacific coast of Panama.

Remarks. — This small species becomes sexually
mature at quite a small size (length of 18 mm.).

Sicyonia parri (Burkenroad)

Figure 24

Eusicyonia parri Burkenroad, 1934a, p. 80, fig. 22. — Lunz, 1945,
p. 5, fig. 2.

Recognition characters. — Resembling S. laevi-
gata; integument rather firm, almost smooth and
more or less sculptured. Rostrum elevated at angle
of about 15 degrees, armed dorsally with three
teeth not counting tip; terminal portion bearing
three teeth with rudiment of another between low-
er teeth. Postrostral carina armed with three large,
subequal teeth, anterior one slightly advanced
beyond level of hepatic spine.

Abdominal segments marked by tergal carinae
notched behind on first to fifth segments. First
abdominal segment with carina produced into an
elevated anterior tooth, marked laterally with a
short anteromedian groove as in S. laevigata, but
reappearing below obliteration and continuing
conspicuously to ventral margin, not connected to
posteromedian pleural groove ventrally. Second
segment with carina cleft above juncture of tergal
grooves. First four segments each with a shallow
but perceptible posterior pleural groove. Fourth
segment with dorsal and ventral positions of
anterior tergal groove separated by narrow area
of obliteration.

Petasma of male with distolateral projections
curved medially at tips; distoventral lobes con-
stricted abruptly near tip.

Measurements. — Length of body: female, 25
mm.

Habitat. — Shallow water to 14 fathoms.

Kicu're 24. — Sicyonia parri i Burkenroad). Carapace and
abdomen in lateral view, approximately X 3 (after
Burkenroad, 1934a).

FISH AND WILDLIFE SERVICE

Type locality.- — Crooked Island, Bahamas.
Known range. — Beaufort, N.C. ; Florida ; West
Indies to Curacao.

Sicyonia brevirostris Stimpson

Figures 25-26

Sicyonia brevirostris Stimpson, 1871b, p. 132. — Hay and Shore,
1918, p. 380, pi. 25, figs. 2, 4.

Eusicyonia brevirostris: Btirkenroad, 1934a, p. 84 (rev.). —
Lunz, 1945, p. 6, fig. 3.

Recognition characters. — Integument firm,
much sculptured, especially abdomen; abdomen
with scattered tubercles, and whole body with
covering of short, fine hairs. Rostrum short, ele-
vated, slender, narrowing considerably to tip; ex-
tending beyond midpoint of cornea; armed
dorsally with two (occasionally three) teeth not
counting tip; terminal portion divided into two
or three teeth with ventral tooth projecting dis-
tally farther than dorsal tooth. High postrostral
carina with three or four teeth behind orbital
margin. Antennal angle armed with a small spine.
Hepatic spine well developed. Ocular stylets long.

Abdominal segments marked by prominent
tergal carinae deeply notched behind on first to
fifth segments. First abdominal segment with
carina produced into an elevated anterior tooth;
marked laterally by four grooves, an antero-
median and posteromedian pleural, a posterior
pleural and posterior tergal. Second and third
segments grooved with two tergals, two median
pleurals extending far dorsad, and a posterior
pleural. Fourth segment grooved with two tergals
and one pleural; fifth with two tergals. Sixth
segment with a posteromedian pleural, anterior
tergal, and a longitudinal groove. Fifth and sixth
segments each with carinal tooth directed pos-
teriorly. Pleura of first four segments armed
with an anterior ventral angle; angle produced

Figure 25. — Sicyonia brevirostris Stimpson. Carapace
and first two abdominal segments in lateral view, 5 mm.
indicated (after Lunz, 1945).

Figure 26. — Sicyonia brevirostris
Stimpson. Petasma of adult
male, ventral view, 1 mm. indi-
cated.

into blunt, outward pointing spine on third and
fourth, sometimes also on second segment. Last
three segments armed with posterior ventral tooth.
Telson ending in a strong point flanked by a
shorter pair of subterminal, often obsolescent,
spines.

Petasma of male with distolateral lobes curved
medially, distoventral lobes curved laterally.

Measurements. — Length of body: males and fe-
males 153 mm.

Variations. — This species exhibits considerable
variation in degree of elevation of the rostrum
(5-45 degrees). The rostral length also varies,
and length and angle of elevation tend to decrease
with increasing age, but this tendency is highly
irregular.

Considerable variation in placement of teeth
on the carapace occurs. The anterior tooth of the
dorsal carina may be located behind the orbital
margin and appear as part of the carapace series,
in which case there are four teeth on the carapace
and two on the rostrum (exclusive of tip) ; or, this
tooth may be located anterior to the orbital margin
and appear as part of the rostral series, in which
case there are three teeth on the rostrum and
three on the carapace.

Color. — Ground color off white to light pink,
pubescence grayish to grayish yellow; dorsal
carina barred with white; appendages reddish

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

purple, thoracic appendages barred with white;
ventral side of abdomen and uropods reddish,
sternal ridges white with purple tipped median
spines. Burkenroad (1939) gave a somewhat dif-
ferent and more detailed color description.

Habitat. — Common in offshore littoral of the
Carolinas; on white shell sand on Campeche
Banks; shallow water to over 100 fathoms in
Carolinas (Broad, 1950), rarely to 180 fathoms.

Type locality. — Cuba.

Known range. — Off Norfolk, Va., through
Bahamas and Gulf of Mexico to Yucatan, Mexico ;
Pacific coast of southern Mexico.

Remarks. — This large sicyonine shrimp is fairly
common in North Carolina and has had a limited
commercial usage. Formerly thought to be rare
in South Carolina (Lunz, 1945), it is now found
to be widely distributed out to the 50-fathom curve
(Lunz, 1957). Eldred (1959) reported few S.
brevirostris in the Tortugas controlled area off
Florida. Hildebrand (1954) found the species to
be fairly abundant on the Campeche fishing
grounds where the bottom is white shell sand.
On the Texas brown shrimp grounds and
Campeche Banks, the species is rare in depths of
15-25 fathoms where S. dorsalis predominates on
mud bottom. In deeper water and on mud bottom,
31—15 fathoms, it is more abundant. It is also
common in shallow water at 6-10 fathoms. Hilde-
brand suggested a distribution in two zones sepa-
rated by an intermediate zone where S. dorsalis
predominates, or possibly the deeper zone of S.
brevirostris over mud represents strays. On
Campeche Banks, S. brevirostris, dorsalis, and
typica have been taken together.

Lunz (1957) reported natural history notes onS.
brevirostris in South Carolina based on 169 suc-
cessful 30-minute hauls with a 20-foot experi-
mental trawl. He found the species most abun-
dant in depths of 35-40 fathoms. Catches at
night were larger than those made in daytime.
Though available throughout the year, largest
catches were made in December. Meager data on
maturity of gonads indicated spring and fall
spawning seasons.

Sicyonia typica (Boeck)

Figure 27

Sicyonia carinata Milne Edwarda, 1830, p. 344, pi. 9, fig. 9. —
Bate, 1S8S, p. 294, pi. 43, egs. 2-3.

Si/nhimanntites typica Boeck, 1864, p. 189. — Danlelssen and
Boeek, 1872. p. 192, flgs. 1-14.— Sars, 1883, pp. 8, 49.

Sicyonia edwardsii Mters, 1881, p. 367.— Milne Edwards and
Bouvier, 1909, p. 251, pi. 8, figs. 1-3 (not fig. 4) (rev.). — Hay
and Shore, 1918, p. 380. Schmitt, 1935a. p. 133 (not fig. 6). —
Lunz, 1945, p. 7, fig. 4.

Sicyonia typica: Burkenroad, 1945. p. 2 (rev.). — Holthuls,
1959, p. 77.

Recognition characters. — Integument rather
firm, more or less sculptured and covered with a
short, thick pubescence more evident dorsally than
ventrally, especially on abdomen. Rostrum ex-
tending halfway along eye, directed obliquely up-
ward, armed dorsally with one or two small teeth
not counting tip. Postrostral carina with two or
three teeth, last two placed behind level of
hepatic spine (third tooth, if present, may look
like part of rostral series). Antenna! angle armed
with a short, often blunt, tooth.

Abdominal segments marked by tergal carinae
deeply notched behind on first to fifth segments;
first segment with carina produced into an ele-
vated anterior tooth; fifth segment with carina
ending posteriorly in a low tooth; sixth segment
with carina produced into a posteriorly directed
tooth. Pleura of first four segments with a ven-
trally directed acute tooth on distal margin
(character apparent only in large adults). Fifth
and sixth segments with tooth at posterolateral
corner of pleura, that of fifth often small and
rectangular. Abdominal grooves deep and well
defined. First segment with posteromedian and
anteromedian grooves connected ventrally. Sec-
ond segment with anterior and posterior tergal
grooves connected dorsally; anterior and median
pleural grooves connected dorsally and ventrally;
a thin and more or less interrupted posterior
pleural groove connected with posterior tergal.
Telson usually lacking subterminal spines.

Measurements. — Length of body :■ 74 mm.

Variations. — Position of the posterior rostral
tooth is variable. In some individuals this tooth

Figure 27. — Sicyonia typica (Boeck). Cara-
pace and first abdominal segment in lateral
view, 1 mm. indicated (after Lunz, 1945).

FISH AND WILDLIFE SERVICE

is located behind the orbital margin, thus appear-
ing as one of the carinal series on the carapace
(Lunz, 1945).

Color. — Blue spots in tail prominent in life;
bright red blotch surrounding rostrum (note by
W. L. Schmitt in U.S. National Museum records).

Habitat. — Between tide marks to 37 fathoms.

Type locality. — Molde Fjord, west coast of Nor-
way [erroneous locality, evidently incorrectly
labeled].

Known range. — Beaufort, N.C. ; east and west
Florida; Gulf of Campeche; Cuba through West
Indies to Rio de Janeiro, Brazil.

Remarks. — Hildebrand (1954) stated that this
species is taken in commercial quantities in the
Gulf of Batabano off southwest Cuba, and occurs
in commercial but unexploited quantities in parts
of the Gulf of Campeche.

There remains some doubt that this species
occurs in North Carolina, though Lunz (1945)
stated that it does. If so, it is not common.

Sicyonia dorsalis Kingsley

Figure 28

Sicyonia dorsalis Kingsley, 1878b, p. 97. — Hay and Shore, 1918,
p. 380, pi. 25, fig. 3.

Eusicyonm dorsalis: Burkenroad, 1934b, p. 121, figs. 13, 14
(rev.). — Lunz, 1945, p. 8, fig. 5.

Recognition characters. — Body small, slightly
compressed. Carapace minutely punctate, less
deep and inflated than 8. stimpsoni. Rostrum ex-
tending horizontally or decurved variable dis-
tance beyond eye; ridge on lateral surface sloping
upward to near dorsal margin; armed dorsally
with three teeth not counting tip, posterior tooth
in front of orbital margin and placed variable
distance from anterior carinal tooth of carapace;
tip appearing bifurcate, dorsal tooth greatly en-
larged, ventral tooth reduced to blunt angle.

Figure 28. — Sicyonia dorsalis Kingsley. Cara-
pace and first abdominal segment in lateral view,
2 mm. indicated l after Lunz, 1945).

Postrostral carina with two teeth, anterior tooth
before level of hepatic spine, posterior tooth near
midpoint. Antennal angle armed with a spine.

Abdominal segments with conspicuous tergal
carinae; margins of notches at posterior ends of
carinae on segments three to five sometimes pro-
duced into long slender spines. First abdominal
segment with tergal carina produced into an
elevated anterior tooth; anteroventral margin of
pleura concave (or at least straight in young)
and with an anterior angle in addition to one in
middle of ventral edge, posterior angle sometimes
produced into a dentiform projection. Second
abdominal segment with tergal and pleural
grooves connected as an uninterrupted groove
extending full depth of segment. Ventral margins
of pleura in segments three and four each with
both anterior and posterior angle, anterior some-
times sharp, posterior sometimes armed with
strong curved spine. Fifth segment with posterior
spine only. Tergal carina of sixth segment ex-
tended into a posterior spine.

Petasma of male with distoventral lobe forked.

Measurements.- — Length of body : male 63 mm. ;
female 71 mm.

Variations. — Angles and spines on the pleura
become better defined with increasing age.

Habitat. — Common on mud bottom (Hilde-
brand, 1954), or mud and shells (Holthuis, 1959) ;
from 3 to 88 fathoms, rarely to 230 fathoms.

Type locality. — Fort Jefferson, Dry Tortugas,
Fla.

Known range. — Cape Hatteras, N.C, to Texas;
Colombia to French Guiana.

Remarks. — Hildebrand (1954, 1955) listed this
species as third in abundance on the brown shrimp
grounds in Texas but less common on Campeche
Banks. It is most common in 15-25 fathoms but
ranges shoreward to depths of 6.5 fathoms, and
small specimens were occasionally taken in the
mouths of bays. Eldred (1959) listed this species
as the most common among Sicyonia species taken
in the Tortugas controlled area in Florida.

Adults of this species fouled with the barnacle,
Balanus amphitnte niveus Darwin, and Polydora
sp., were reported from the Gulf of Mexico off
Marquesas Key by Eldred (1962). Such speci-
mens, ranging in size from 58 to 70 mm. total
length, were judged to be near maximum size
for the species.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763^049 O — 65 4

Sicyonia stimpsoni Bouvier

Figure 29

Sicyonia stimpsoni Bouvier, 1905, p. 748. — Holthuls, 1959,
p. 75.

Sicyonia dorsalis: Milne Edwards and Bouvier, 1909, p. 253,
text-flgs. 86-88, pi. 8, flgs. 4-13.

Eusicyonia stimpsoni: Burkenroad, 1934b, p. 121 (notes). —
1939, p. 57.

Eusicyonia edwardsii: Sehmltt, 1935a, p. 133, 8g. 6.

Recognition characters. — Rostrum usually ele-
vated at considerable angle, extending variable
distance beyond eye; with three dorsal teeth not
counting tip, posterior tooth in front of orbital
margin separated by a variable distance from
anterior carinal tooth of carapace; tip often
appearing bifurcate but a third ventral tooth
present behind or below level of anterior cleft;
a slight ridge on lateral surface running parallel
with ventral margin. Postrostral carina with two
teeth, anterior tooth before level of hepatic spine,
posterior tooth behind midpoint ; sometimes rudi-
ment of a third tooth appearing as a minute crest-
like swelling with truncated anterior edge a little
in front of posterior tooth. Antennal angle armed
with a spine.

Abdominal segments with conspicuous tergal
carinae. First segment with carina produced into
an elevated anterior tooth. Margins of dorsal
notches at posterior ends of segments three to five
produced as short angular projections. A tooth
at posterior end of fourth to sixth segments. Seg-
ments one to four with a ventral spine on pleura ;
segments five and six with spine at posteroventral
corner. Second abdominal segment with pleural
groove curving forward midlaterally, not connect-
ed to short tergal groove curving downward and
backward.

Figure 29. — Sicyonia stimpsoni Bouvier. Carapace
and ixjrtion of first abdominal segment in lateral
view, 2 mm. indicated (after Lunz, 1945).

Petasma of male with distoventral lobe not
forked.

Measurements. — Length of body : male, 14 mm. ;
female, 60 mm.

Variations. — Pleural spines may be absent in
young individuals.

Color. — Branchial region of carapace with
orange, or brownish and yellowish-white ring in
posterior half (Holthuis, 1959). North Carolina
specimens show a purple spot with surrounding
vermilion ring in this region.

Habitat. — Found on predominantly mud and
shell bottom in Surinam (Holthuis, 1959); shal-
low water to 230 fathoms.

Type locality. — Off Barbados, British West
Indies, lat. 13°03'05" N. long. 59°36'18" W., depth
103 fathoms.

Known range. — Cape Hatteras, N.C., to
Campeche Gulf; West Indies to French Guiana.

Remarks. — Among species of Sicyonia occur-
ring in the Carolinas, the only detailed description
of development is that given by Pearson (1939)
for this species. Eggs attributed to this species
were taken in inlets, and larval development (re-
constructed from plankton) proceeded through
five naupliar, three protozoeal, and two mysis
stages. Eggs were taken abundantly at St. Augus-
tine Inlet, Fla., in plankton, from March 30 to
August 8; they were taken in lesser abundance
from January to March, and August to Septem-
ber at Fort Pierce, Fla., and off Stono Inlet, S.C.,
in September. Naupliar and protozoeal stages
were found from April to August, and mysis
stages were found in January and August-
September. Thus, the breeding season along that
stretch of coast lasts at least from January to
September.

Holthuis (1959) noted that males in Surinam
material outnumbered females about 3 to 1.

Family Sergestidae

Penaeidea with last two pairs of legs reduced
in size or lost; gills few or lost.

KEY TO SUBFAMILIES AND SPECIES IN THE
CAROLINAS

a. Head not greatly elongated : gills present

Sergestinae; Antes mnrricanus rarolinac (p. 39).
aa. Head greatly elongated ; gills absent

Luciferinae ; Lucifrr f<i.r<mi (p. 40).

FISH AND WILDLiFE SERVICE

Subfamily Sergestinae

Carapace moderately compressed. Inferior an-
tennular flagella present ; with prehensile organ in
male. Second and third pair of legs, at least,
terminated by a pincer. Gills present. Sixth
abdominal segment and telson without sexual dif-
ferences; without protuberances or ventral pro-
cesses in males. Petasma with a short base. No
protuberance on peduncle of first pleopod (after
Hansen, 1922).

Genus Acetes Milne Edwards, 1830

Burkenroad, 1934a, p. 99. — 1934b, p. 126.
Acetes americanus carolinae Hansen

Figures 30-31

Acetes americanus Ortmann, 1893, p. 39. pi. 2, fig. 2.
Acetes carolinae Hansen, 1933, p. 31, figs. 1-8.
Acetes americanus carolinae: Holthuis, 1959, p. 49, fig. 1, a-c
(rev.).

Recognition characters. — Body small. Integu-
ment thin, smooth, polished. Carapace with
rostrum elevated, short; a single tooth behind
acute tip. A prominent spine on rounded ridge
behind eye; hepatic spine small. Eyes prominent,
stalk conical, cornea large. Antennules with pe-
duncle long, third article more than twice length
of second article, lower flagellum much shorter
and more slender than upper, upper hairy ventral-
ly near base; in males, curved lower flagellum
forming clasping organ, basal four annulations
thicker than distal annuli, third and fourth armed
dorsally with a short row of spines, distal one
strongest. Antennal scale reaching end of second
article of antennular peduncle in males, beyond
end of second article in females.

Figure 30. — Acetes americanus carolinae Hansen,
in lateral view, X 4.8.

Female

Figure 31. — Acetes americanus carolinae Hansen.

A, clasping organ on antennule of male X 50;

B, petasma of male, right side in posterior view
X 90; C, tip of petasma, anterior view of right
side X 90.

Sixth segment of abdomen with convex ventral
margin bifurcated caudally. Exopod of uropod
about 4.5 times longer than broad ; proximal three-
fifths of outer margin smooth, ending in a minute
tooth, remainder of margin hairy.

Petasma of male with membranous, triangular-
tipped external portion exceeded by slender
median part; median portion ending in compli-
cated capitulum, a distomedian crooked lobe
tipped with four thick, short spines, and three
other shorter lateral lobes each produced into
an acute point. Lobes behind base of last pair
of legs greatly enlarged in males forming genital
coxae broader than long. Coxae of third legs
in females with posteromedian corner produced
into a protuberance; sternite immediately behind
third legs bearing two curved projections forming
a U-shaped thelycum.

Measurements. — Length of body : 15 to 26 mm.

Variations.— Holthuis (1948, 1959) followed
Burkenroad (1934a) in considering the known
species of Acetes from the western Atlantic with
one tooth behind the tip of the rostrum to be all

MARINE DECAPOD CRUSTACEAN'S OF THE CAROLINAS

A. americanus. Burkenroad recognized four sub-
species: A. americanus americanus Ortmann,
Brazil; .4. a. limonensis Burkenroad, Panama; A.
a. louisianensis Burkenroad, Louisiana; A. a.
carolinae Hansen, North Carolina. Holthuis con-
sidered these to be clinal variants, with the north-
ern and southern representatives differing most
widely from each other. Females of the four
doubtfully valid subspecies differ in depth of the
concavity in the middle of the posterior segment
of the genital sternite. This structure is deeper
than broad in Carolinian specimens, but becomes
shallower in progressively more southern forms.
Holthuis suggested that the extreme northern and
southern forms might deserve to retain subspecific
rank.

Color. — Nearly transparent with faint red
flecks.

Habitat. — Littoral oceanic and estuarine waters
to 23 fathoms.

Type locality. — Typical form, mouth of Para
(=Tocantins) River, [State of Para], Brazil.
Northern form, off Beaufort Inlet, N.C.

Known range. — Cape Lookout, N.C, to mouth
of Para River, Brazil.

Remarks. — Burkenroad (1934b) found larval
stages of this Acetes at the surface of the outer
littoral of Louisiana in spring. He described the
spermatophore as gourd-shaped, much as the
spermatophore of Lucifer, and gave other struc-
tural details of the reproductive system.

In Bogue Sound, near Beaufort Inlet, N.C,
specimens have been taken in every month of the
year in a large plankton net fished from a pier
at the surface on flood tides at night. Gutsell {in
Hansen, 1933) reported that this species can some-
times be taken near Beaufort Inlet, N.C, "in gal-
lons at a time," especially in late summer and
early fall.

Subfamily Luciferinae

Carapace extremely compressed. Antennules
without inferior flagella in both sexes. Third pair
<>f legs only terminated by a pincer. Gills absent.
Sixth abdominal segment of male with two ventral
processes, second far behind first. Telson of male
with a strong protuberance on internal face.
IViasma sessile, proximal part fixed like a large
disc on peduncle of first pleopod; each peduncle,

near disc, possessing a protuberance with distal
spines (after Hansen, 1922; Burkenroad, 1934b).

Genus Lucifer Thompson, 1829

Hansen. 1919. p. 48.

Lucifer faxoni Borradaile

Figure 32

Lucifer jajconi Borradaile, 1915, p. 227. — Hay and Shore, 1918,
p. 381, text-fig. 4, pi. 26, fig. 10.— Holthuis, 1959, p. 52 (rev.).

Recognition characters. — Body small, thin; in-
tegument smooth, thin, transparent. Anterior
portion of cephalothorax cylindrical, greatly
lengthened (about 1.5-2.5 times longer than pos-
terior portion), bearing eyes, antennules, and
antennae far in front of mouth parts and legs.
Rostrum small, a spine on each side behind eye
and at anterolateral corner. Posterior portion of
cephalothorax with spine on each side in front.
Eyes large, prominent, on stout conical stalks
about one-fourth to one-third length of anterior
part of cephalothorax. Peduncles and flagella of
antennules long, slender. Peduncle of antennae
about half as long as first article of antennular
peduncle ; flagellum longer than that of antennule ;
antennal scale almost linear, fringed on inner
margin with long hairs.

Third maxilliped long, pediform. Three pairs
of legs; first pair short; last two pairs of equal
length extending almost to end of cephalothorax.

Abdomen much compressed; segments deepest
and produced into spiniform angle where pleopods
originate. Sixth segment as long as preceding
two segments, posterolateral angles spiniform near

Figure 32. — Lucifer faxoni Borradaile. A, male in lat-
eral view; B, sixth abdominal segment and tail fan of
female in lateral view: 1 mm. indicated.

FISH AND WILDLIFE SERVICE

base of uropods; a small median spine above base
of telson; male with two strong ventral spines,
posterior spine curved and about twice length of
anterior spine. Telson slender, about half length
of uropods; truncate distally with a strong spine
at each corner; two pairs of intermediate spines
on distal border, and two pairs of lateral spines
about equidistant; males with a prominent ventral
projection on distal half. Outer ramus of uropod
longer and broader than inner.

Petasma of male membranous, folded, foliace-
ous; ventral process needlelike, curved, tapering to
acute end directed ventrolaterally.

Measurements. — Length of body: 10-12 mm.

Color. — Almost perfectly transparent in life.

Habitat. — Oceanic and estuarine waters from
surface to 50 fathoms.

Type locality. — Off Chesapeake Bay.

Known range. — Off Nova Scotia along coast of
United States to Louisiana; through "West Indies
and along coast of South America to off Rio de
Janeiro, Brazil; Bermuda and mid-Atlantic
(lat, 42°50'26" N. long. 41°48' W., lat. 41°39'34"
N. long. 39°21' W., and lat. 4°30' N. long. 28°20'
W.) ; Rea Sea; Malay Archipelago; Marshall
Islands; Hawaiian Islands; Fanning Island
(Holthuis, 1959).

Remarks. — This interesting little shrimp is
abundant near Beaufort Inlet, N.C., throughout
most of the year (collected from February
through October), and often occurs in swarms
outside the harbor.

Brooks (1882) worked out the larval develop-
ment of a species of Lucifer in the Beaufort, N.C.,
area, and from his figures and present knowledge
of distribution, it is almost certain that he was
dealing with L. faxoni. Brooks found egg-bearing
females only in April, but found larvae as late
as September. Since then, egg-bearing females
have been found through the summer into October
in Bogue Sound near Morehead City, N.C. Brooks
illustrated the egg, a number of larval stages (two
nauplius, three protozoea, one zoea, one schizopod,
one mastigopus, and one lucifer), and a final adult
stage in males.

As various authors have pointed out, Brooks
mistakenly thought that the species was primarily
estuarine, the adults leaving the marshes on ebb
tides to spawn in the ocean, because he found the
species most concentrated in the estuary near

Beaufort on ebb tides. He failed to find specimens
on flood tide. The species can be found in estu-
aries on both flood and ebb tide, but its primary
home is the ocean.

Burkenroad (1934b) reported a female with
large ova from the outer littoral of Louisiana.
He gave a detailed account of the reproductive
systems of males and females showing that they
are fully bilateral and not asymmetrical as stated
by Brooks (1882), Bate (1888), and Hansen
(1922). The males, however, carry but one sper-
matophore at a time, possibly because the body
is so strongly compressed.

Section Caridea

Pleura of second abdominal segment overlap-
ping those of first and third segments. Third legs
never with chelae. Gills phyllobranchiate (Hol-
thuis, 1955).

Family Pasiphaeidae

Rostrum small or obsolete. Mandibular palp
absent, one or two jointed. Legs with exopods;
first two pairs of legs chelate, chelae slender, cut-
ting edges pectinate ; third, fourth, and fifth legs
smaller than chelipeds, fourth generally smallest
(Rathbun, 1901; Holthuis, 1955).

Genus Leptochela Stimpson, 1860

Stimpson, 1860, p. 111.— Hemming, 195Sb. p. 157.

Leptochela serratorbita Bate

Figures 33-34

Leptochela serratorhita Bate, 1888, p. 859, pi. 139, fig. 1. —
Rathbun, 1901, p. 127. — Sehmitt, 1935a, p. 134.

Recognition characters. — Carapace smooth, an-
terior half with low carina. Rostrum nearly hori-
zontal, unarmed, about as long as eyestalks.. Upper
portion of orbits finely serrated or spinulose.

Figure 33. — Leptochela serratorbita Bate,
eral view, 1 mm. indicated.

Animal in lat-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure 34. — Leptochela serrator-
bita Bate. Uropods and telson
in dorsal view. 1 mm. indicated.

Antennal spine small or absent. Antennular pe-
duncle reaching beyond middle of antennal scale.

First two pairs of legs chelate; fingers a little
longer than palm, cutting edges pectinate.

Abdomen with fourth and fifth segments
broadly carinate; sixth segment with an anterior
middorsal tubercle, a posterior spine either side
of middle and a prominent spine preceding each
posterolateral angle. Telson with an anterior
submedian pair of spines and three pairs of lateral
marginal spines, anterior lateral spines at anterior
fourth, second at middle, third near posterior
extremity; tip with three pairs of unequal spines
and two pairs of strong setae, all more or less
fimbriated. Exopod of uropod with a row of
spines along ventrolateral border, a long curved
spine at tip; endopods spiny near tip.

Measurements. — Length of body : 21 mm.

Habitat. — Known only from coastal and oc-
casionally estuarine waters, from surface to 23
fathoms (perhaps to 33 fathoms).

Type locality.— St, Thomas, shallow water.

Knoxon range.— Ne&r Beaufort Inlet, N.C.;
Charleston Harbor, S.C. ; Key West, Fla. ; Puerto
Rico, and Virgin Islands.

Remarks.— This small shrimp has been taken
in May, July, October, and November in surface
plankton tows in Bogue Sound, near Beaufort
Inlet, N.C., on flood tides at night. The specimen
taken in May was ovigerous. Lunz (1939) col-
lected a specimen in July in South Carolina.

Family Palaemonidae
Caridea having first two pairs of legs chelate,
second pair usually larger than first, carpus of
second pair not subdivided. Rostrum usually
armed with teeth and not movable. Mandibles
usually with an incisor process (Holthuis, 1951a).

KEY TO SUBFAMILIES IN THE CAROLINAS

a. Posterior margin of telson with three pairs of spines

Pontoniinae (p. 42).

aa. Posterior margin of telson with two pairs of spines

and two or more setae Palaemoninae (p. 50).

Subfamily Pontoniinae

Upper antennular flagellum with both rami
fused in basal part. Appendix masculina general-
ly present on second pleopod of male; appendix
interna on second pleopod of female. Pleurobranch
absent from third maxilliped. Posterior margin
of telson with three pairs of spines (Holthuis,
1951a).

KEY TO GENERA AND SPECIES IN THE CAROLINAS

(Holthuis, 1951a, modified)
a. All maxillipeds with well-developed exopods.

b. Hepatic spine present Periclimenes (p. 42).

c. Antennal spine absent ; dactyls of last three legs

bifurcate P. longimiidatus (p. 42).

cc. Antennal spine present ; dactyls of last three legs

simple P. americanus (p. 43).

bb. Hepatic spine absent,
c. Rostrum compressed, with distinct teeth

Pcriclimenaeus (p. 45).
d. Antennal scale with no terminal tooth

P. schmitti (p. 45 i.
dd. Antennal scale with terminal tooth

P. irilsoni (p. 46).
cc. Rostrum depressed, with at most two small teeth

near tip Pontonia (p. 47).

d. Dorsal spines of telson small and rather incon-
spicuous P. domestica (p. 47).

dd. Dorsal spines of telson well developed

P. margarita (p. 48).
aa. Second and third maxillipeds without exopods

Xeopontoiiides ieoufortenms (p. 49).

Genus Periclimenes Costa, 1844
Subgenus Periclimenes Costa, 1844

Holthuis, 1951a, p. 23, 26.— Hemming, 1958b, p. 159.

Periclimenes (.Periclimenes) longicaudatus (Stimpson)
Figure 35

Urocaris longirauilata Stimpson, 1860, p. 39. — Hay and Shore,
1918, p. 394, pi. 27, fig. 7.

Periclimenes (Periclimenes) longicauilatus: Holthuis, 1951a,
p. 26, pi. 6, figs, a-m ; pi. 8, fig. m (rev.).

Recognition characters. — Rostrum straight,
short, reaching to end of second or third article

FISH AND WILDLIFE SERVICE

Figure 35. — Periclimenes (Periclimenes) longicaudatus
(Stimpson). A, anterior part of body in lateral view,
X 5; B, antennule, X 11.5; C, antennal scale, X 11.5;
D, first leg, X 13.0; E, second leg, X 13.0 (after Hol-
thuis, 1951a).

of antennular peduncle; upper margin raised into
a high arcuate crest with seven to nine teeth, first
two teeth behind orbit more widely spaced than
distal teeth ; lower margin with one or two small
spines near tip. Carapace with lower angle of
orbit produced into a lobe constricted at base;
supraorbital and antennal spines absent; antero-
lateral angle rounded. Eyes well developed and
elongate. Stylocerite well developed but not reach-
ing to middle of basal antennular article; basal
antennular article convex and ending in a strong
spine ; upper antennular flagellum with two rami
fused for four to eight joints. Antennal scale with
outer margin slightly concave, ending in a strong
tooth exceeded distally by lamella; antennal pe-
duncle reaching almost to middle of scale, with
distinct outer spine near base of scale. AH
maxillipeds with well-developed exopods.

First legs slender, reaching almost to end of
antennal scale ; second legs equal in size and shape,
stronger and longer than first legs.

Abdomen smooth; all pleura rounded. Third
abdominal segment somewhat produced in middle
of posterior margin. Sixth abdominal segment
twice length of fifth and longer than telson. Tel-
son with two pairs of dorsal spines both lying
behind middle ; posterior margin with three pairs
of spinules.

Measurements. — Length of body : male, 17 mm. ;
ovigerous females, 15 to 22 mm.

Color. — Body transparent in life.

Habitat. — This species is found in abundance
on submerged vegetation along with Hippolyte
and Tozeuma, on Leptogorgia,, algae and Sargas-
sum, or from sponges (Schmitt, 1924b) ; however,
it is hard to detect because of its almost perfect
transparency. Surface to 6 fathoms, rarely to 15
fathoms.

Type locality.— Const of Carolina.

Known range. — Hatteras, N.C., to southwestern
Florida ; West Indies to State of Paraiba, Brazil.
There are doubtful records from the Indian Ocean
and deeper waters of the Gulf of Mexico (Hol-
thuis, 1951a).

Remarks. — This species is abundant in the
Beaufort, N.C., area, and has been collected there
throughout the year. Ovigerous females have been
found from May through October. They occur
in Cuba in January and March (Schmitt, 1924b)
and in Texas in May. Pearse and Williams (1951)
found the form on reefs off the North Carolina
coast along with an unidentified Periclimenes.
Last larval, postlarval, and early juvenile stages
doubtfully assigned to this species have been de-
scribed by Gurney and Lebour (1941) from
Bermuda.

Subgenus Harpilius Dana, 1852

Holthuis, 1951a, p. 23.

Periclimenes (Harpilius) americanus (Kingsley)

Figure 36

Anchistia americana Kingsley, 1878b, p. 96.
Periclimenes (Harpilius) americanus: Holthuis, 1951a, p. 60,
pi. 18, figs, a-j ; pi. 19, flgs. a-e (rev.).

Recognition characters. — Rostrum rather high
and straight ; tip directed upward, reaching about
to end of antennular peduncle; upper margin
nearly straight, with 7-10 teeth, first two behind
orbit and considerably separated; lower margin
with 2, sometimes 3 teeth but with an unarmed
stretch before tip. Carapace with only antennal
and hepatic spines; lower orbital angle acute;
postorbital ridge paralleling orbit; anterolateral
angle broadly rounded. Eyes well developed;
cornea globular, two dark-colored bands visible
on cornea in fresh material; an ocellus present.
Stylocerite rather strong, sharply pointed, almost-
reaching middle of basal antennular article ; outer

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure 36. — Periclimenes (Harpilius) umericanus (Kings-
ley ) . A, anterior part of body in lateral view, X 8.5 ;
B, antennule, X 11 ; C, antennal scale, X 11 ; D, first
leg, X 11 ; E, F, second leg (different specimens), X 7.5
(after Holthuis, 1951a).

margin of basal antennular article convex, ending

in well-developed anterolateral tooth; second and
third articles elongate, second slightly shorter
than third; upper antennular flagellum with 2
rami fused for 8-12 joints (often 6 in younger
specimens), free portion of shorter ramus with 3
or 4 joints, length less than one-fourth that of
fused part. Antennal scale slightly exceeding

antennular peduncle, outer margin straight or
slightly concave and ending in a strong tooth J
slightly exceeding distally narrowed lamella; I
scale with a distinct spine near base; antennal I
peduncle not reaching to middle of scale. All I
maxillipeds with well-developed exopods.

First legs slender; chela and sometimes a small I
portion of carpus extending beyond antennal I
scale; fingers smooth, as long as palm. Second I
legs equal in size and shape, very strong and I
longer than first; adult males with fingers less I
than half as long as palm, three or four teeth on I
cutting edges leaving gape at midlength when I
closed; second legs shorter and fingers not agape |
in juveniles and adult females.

Abdomen with pleura of first four segments
rounded, of fifth ending in a small tooth ; median
posterior margin of third only slightly produced
posteriorly. Sixth segment about 1.5 times as
long as fifth and about three-fourths length of
telson. Telson with two dorsal pairs of spines at
one-third and two-thirds length ; posterior margin
with three pairs of spines, intermediate pair less
than twice length of inner spines.

Measurements. — Length of body : male 22 mm. ;
ovigerous females, 13 to 20 mm.

Variations. — The carpus of the second pair of
legs varies in length as do the dactyls of the last
three pairs of legs.

Color. — Ground color translucent grayish
white; carapace with three oblique orange-brown
lateral lines and a pair of dorsal lines running
back from base of rostrum; each abdominal seg-
ment crossed by a narrow brown band and a row
of small dark spots on posterior margin ; tail fan
with two larger lateral and median spots and an
orange-brown tip (Verrill, 1922). "

Habitat. — This species lives in coastal waters,
preferring sandy or rocky bottom, often between
algae or coral. Verrill (1922) found large schools
near the surface in Bermuda, and Gurney (1943a)
found it to swim singly or in small numbers at
the surface at night in certain periods of the
lunar cycle (see Holthuis, 1951a). Shallow water
to 40 fathoms.

Type locality. — Key AVest, Fla.

Known range.- — Beaufort, N.C.; Jupiter Inlet,
Fla., to west coast of Florida off Hernando
County; off Cape Catoche, Yucatan, Mexico;
through West Indies to Aruba; Bermuda.

FISH AND WILDLIFE SERVICE

Remarks. — Gurney (1943a) listed this species
as one of the commonest decapod crustaceans in
the littoral region of Bermuda. Females out-
numbered males two to one; however, ovigerous
females were never collected there. From plank-
ton, Gurney (1936c, 1943a) described the first and
fifth larval, and the first postlarval stages, and
gave remarks on allometric growth of the second
legs. These legs are stronger and longer in males
than in females, with fingers agape in old males.
The center of greatest growth is in the palm.

Ovigerous females have been found from Jan-
uary to May and from September to November
in Florida, the West Indies, and South America.

Holthuis (1951a) listed P. americcmus as com-
mon in North Carolina, but it has been taken
only once (August 5, 1958) in surface plankton
tows in Bogue Sound that have produced hun-
dreds of P. longicaudatus.

Genus Periclimenaeus Borradaile, 1915

Holthuis, 1951a, p. 76. — Hemming, 1958b, p. 159.
Periclimenaeus schmitti Holthuis

Figure 37
Periclimenaeua schmitti Holthuis, 1951a, p. 90, pi. 27, figs. a-m.

Recognition characters. — Rostrum short,
straight, or somewhat decurved, not reaching to
end of basal article of antennular peduncle; up-
per margin bearing one or two teeth, exclusive
of upturned tip; lower margin convex, unarmed.
Carapace smooth; postorbital ridge paralleling
orbit, extending from strong antennal spine dor-
sally and becoming gradually obsolete; antero-
lateral angle broadly rounded, produced forward.
Eyes well developed, cornea globular, shorter and
narrower than eyestalk. Basal article of antennu-
lar peduncle with short, broad, blunt tipped
stylocerite reaching about to middle of article;
outer margin with blunt angle at level of sty-
locerite tip, concave beyond angle, anterolateral
angle of article with rather large tooth; second
and third articles short ; upper antennular flagel-
lum with three fused joints, free part of short
ramus with one short joint. Antennal scale
broadly ovate; outer margin nearly straight, with
no terminal tooth.

First leg with carpus and chela extending be-
yond antennal scale; chela slender, fingers two-
thirds length of palm, unarmed, carpus about as

long as chela, slightly shorter than merus. Sec-
ond legs unequal, both reaching with chela and
part of carpus beyond antennal scale. Larger
second leg heavy, fingers slightly less than half
as long as palm, inwardly curved; upper margin
of dactyl broadly rounded, cutting edge finely
denticulate distally, with large rectangular-
shaped tooth fitting into pit on immovable finger
when closed; fixed finger with strong, narrow
tooth at inner margin of pit ; palm swollen, cov-
ered with a number of small scalelike tubercles;
carpus conical, about one-fourth length of palm;
merus about one-third length of palm, sometimes
with small tubercles at lower edge. Smaller second
leg with fingers straight, slightly shorter than
one-third length of palm; cutting edge of dactyl
denticulate throughout, that of fixed finger
straight ; tubercles on palm fewer than on opposite
member. Third leg with propodus and part of

Figure 37. — Periclimenaeus schmitti Holthuis. A, an-
terior part of body in lateral view, X 17 ; B, antennule,
X 22.5; C, antenna, X 22.5; D, first leg, X 22.5; B,
chela of first leg, X 33.5 ; F, larger second leg, outside,
X 15 ; G, fingers of larger second leg, inside, X 15 ; H,
smaller second leg, X 15 ; I, third leg, X 15 ; J. dactyl
of third leg, X 56.5 (after Holthuis, 1951a).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

carpus reaching beyond antennal scale, dactyl
short, distinctly bifurcate.

Abdomen smooth; pleura of first five segments
rounded ; sixth segment about as long as fifth and
about two-thirds length of telson. Telson with
two pairs of small dorsal spines somewhat re-
moved from lateral margin, placed at one-third
and two-thirds length; six spines on posterior
margin placed in one row, intermediate spines
longest. Uropods broadly ovate, exopod with
outer margin ending in a tooth flanked medially
by a movable spine.

Measurements. — Length of body: ovigerous fe-
male, 20 mm.

Variations. — Specimens with a single rostral
tooth are young.

Habitat. — Shallow water.

Type locality. — Tortugas, Fla.

Known range. — Bogue Sound, N.C. ; Tortugas,
Fla.

Remarks. — Two specimens from North Caro-
lina were taken August 16, 1957, in a nighttime
surface plankton tow on flood tide near Beaufort
Inlet. Though these have intermediate spines on
the telson longer than the other terminal pairs,
they agree well with specimens of P. schmitti
from Tortugas.

Periclimenaeus wilsoni (Hay)

Figure 38

Coralliocaris wilsoni Hay, 1917, p. 71. — Hay and Shore, 1918,
p. 394, text-fig. 13 ; pi. 27, fig. 8.

Periclimenaeus wilsoni: Holthuls, 1951a, p. 103, pi. 31, figs.
a-m ; pi. 32, figs, b-c (rev.).

.Recognition characters. — Rostrum nearly
straight or somewhat decurved, almost reaching
end of antennular peduncle ; upper margin some-
what convex, bearing 10 to 12 regularly spaced
teeth, first tooth directly over or immediately be-
hind orbital margin; lower margin straight or
concave, unarmed. Carapace smooth with only
an antennal spine placed close to acute lower
orbital angle; postorbital ridge paralleling orbit
indistinct; anterolateral angle somewhat ante-
riorly produced, broadly rounded. Eyes well
developed. Stylocerite of antennular peduncle
broad, short, and pointed, almost reaching middle
of basal article; outer margin of basal article
with a blunt angle near tip of stylocerite, concave
beyond angle, ending in a strong tooth; second

Figure 38. — Periclimenaeus wilsoni (Hay). A, anterior
part of body in lateral view, X 11.5 ; B, antennule, X
9.5 ; C, antenna, X 9.5 ; D, first leg, X 9.5 ; B, smaller
second leg, X 9.5 ; P, larger second leg, X 4.5 ; G, third
leg, X 9.5; H, dactyl of third leg, X 56; I, telson in
dorsal view, X 17 (after Holthuis, 1951a).

and third antennular articles about same size;
upper antennular flagellum with sis to nine fused
joints; free part of short ramus with two joints.
Antennal scale a little longer than antennal pe-
duncle; outer margin straight, ending in a small
spine; lamella broadest proximally.

First legs with carpus and chela extending be-
yond tip of antennal scale ; chela rather thickset ;
fingers shorter than palm, unarmed ; carpus about
as long as merus. Second legs strong, unequal,
with part of carpus and chela extending beyond
tip of antennal scale. Larger second legs with
chela almost equal to bulk of body; fingers in-
wardly curved, somewhat less than half length
of palm; dactyl with upper margin convex, cut-

FISH AND WILDLIFE SERVICE

ting edge with large rectangular tooth fitting
into pit on immovable finger when closed; im-
movable finger with distinct tooth at inner margin
of pit; palm swollen, tuberculate at base and on
base of fingers, tubercles on proximal lower part
of palm arranged in rows or honeycomb pattern;
carpus smooth, short, cup-shaped; merus about
one-third length of palm. Smaller second leg
much as larger one in general shape; palm some-
what swollen, with scattered tubercles anteriorly.
Third leg with greater part of propodus reaching
beyond tip of antennal scale; dactyl short, broad,
bifurcate.

Abdomen smooth ; pleura of first five segments
broadly rounded; sixth segment half length of
telson. Telson with two pairs of dorsal spines
somewhat removed from lateral margin, anterior
pair close to anterior margin, posterior pair
slightly behind midlength; posterior margin with
three pairs of spines, outer pair short and located
in advance of larger intermediate and inner pairs.
Uropods broadly ovate, outer margin of exopod
ending in a tooth flanked medially by a movable
spine.

Measurements. — Length of body : male, 20 mm. ;
ovigerous females, 16 to 20 mm.

Variations. — Juveniles may have a shorter ros-
trum with fewer dorsal teeth, and in some speci-
mens the second chelae may be smooth.

Color. — Clear, milky white; integument so
transparent that color of internal organs is plainly
visible; egg masses light bluish green.

Habitat. — This species is known to live in
sponges in coastal waters in company with
Synalpheus longicarpus and S. toivn-sendi; 10^0
fathoms.

Type locality. — Fishing grounds, 20 miles off
Beaufort Inlet, N.C.

Known range. — Off Beaufort, N.C. ; off Logger-
head Key, near Tortugas, and Franklin County,
Fla.

Remarks. — Ovigerous females have been re-
ported from Florida in July and North Carolina
in August. Gurney and Lebour (1941) described
the last larval stage of a shrimp doubtfully re-
ferred to P. wilsoni.

When disturbed, the animals are able to make
a snapping sound with the large chela quite as
loud as that made by one of the true snapping
shrimps.

Genus Pontonia Latreille, 1829

Holthuie, 1951a. p. 115.— Hemming, 1958b, p. 124.

Pontonia domestica Gibbes

Figure 39

Pontonia domestica Gibbes, 1850, p. 196. — Holthuls, 1951a,
p. 122, pi. 38, figs, a-j (rev.).

Recognition characters. — Rostrum depressed,
rather narrowly triangular, decurved ; reaching to
second article of antennular peduncle; tip acute

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure 39. — Pontonia domestica Gibbes. A, anterior part
of body in dorsal view, X 5.5 ; B, antennule, X 7.5 ; C,
antennal scale, X 7.5; D, first leg. X 5.5; E, larger
second leg, X 2.5 ; F, smaller second leg, X 2.5 ; G, third
leg, X 5.5; H, dactyl of third leg, X 20; I, telson in
dorsal view, X 9.1 (after Holthuis, 1951a).

in dorsal and lateral view, flat dorsally; an in-
conspicuous longitudinal carina ventrally; an
inconspicuous dorsal and ventral tooth near tip
with tuft of long hairs between upper tooth and
apex. Carapace with lower orbital angle bluntly
triangular, a strong antennal spine below angle;
anterolateral angle broadly rounded and anterior-
ly produced. Eyes well developed, not reaching
laterally to antennal spine. Antennular peduncle
with stylocerite broad, bluntly pointed; antero-
lateral angle of basal article produced forward,
rounded ; third article longer than second ; upper
antennular flagellum with 7-10 fused joints; short
ramus with 2 or 3 joints. Antennal scale broadly
oval, outer margin a little convex, terminal tooth
small, exceeded by lamella; antennal peduncle
reaching beyond middle of scale.

First leg with carpus and chela reaching beyond
antennal scale; fingers of chela somewhat longer
than palm; carpus as long as merus. Second legs
strong, unequal in size and shape; carpus and
chela reaching beyond antennal scale. On one leg,
fingers about half length of palm; immovable
finger somewhat higher than dactyl and bearing
two large teeth on cutting edge, anterior tooth
triangular, at middle of edge, posterior tooth
truncate with crenulate margin; dactyl with one
tooth; palm with upper and lower margin some-
what compressed, surface appearing minutely
roughened under magnification; carpus short,
conical, with a depression above and a knob below ;
merus a little longer than carpus. Other second
leg much as above but with relatively longer
fingers; immovable finger higher in comparison to
dactyl; teeth smaller and carpus more slender.
Remaining legs with bifurcate dactyls.

Abdomen with first five pleura broadly rounded.
Sixth segment with pleura and posterolateral
angle ending in slender, sharp spines; slightly
lunger than fifth segment. Telson half again as
long as fifth segment ; two dorsal pairs of spines
on lateral margin of telson small, almost invisible;
anterior pair about in middle, posterior pair closer
to posterior border than to anterior pair; posterior
border with three pairs of spines in a row; inner
i wo pairs equal in length, outer pair smaller;
uropods broadly ovate, outer margin of exopod
ending in blunt angle with small movable spine
at tip.

Measurements. — Length of body : male 32 mm.

Color.- — Translucent white.

Habitat. — The species lives commensally in
lamellibranch mollusks in coastal waters and has
been recorded from Atrina seminuda, A. serrata,
and Pecten sp. (Holthuis, 1951a) ; shallow water
to 23 fathoms.

Type locality.- — South Carolina.

Knoxon range. — Atlantic Beach near Beaufort
Inlet, N.C., to Chandeleur Islands, La.; Baha-
mas; Madeira.

Remarks. — Brooks and Herrick (1892) illu-
strated a section through the segmenting egg of
Pontonia domestica on plate 28.

Pontonia margarita Smith

Figure 40

Pontonia margarita Smith, 1869c, p. 245. — Holthuis, 1951a, p.
13X, pi. 43, figs, a-1 ; pi. 44, figs, a-h (rev.).

Recognition characters. — Rostrum depressed
and decurved, dorsally flat and triangular; tip
reaching to end of basal article of antennular
peduncle or slightly beyond; an inconspicuous
dorsal and ventral tooth near tip with small tuft
of hairs between upper tooth and apex; a longi-
tudinal median carina ventrally. Carapace
smooth; with strong antennal spine located well
below narrowly rounded lower orbital angle;
anterolateral angle broadly rounded and ante-
riorly produced. Eyes somewhat larger than in
P. domestica. reaching laterally beyond antennal
spine. Basal article of antennular peduncle with
blunt-pointed stylocerite more or less pressed
against outer border; anterolateral angle of article
produced forward, rounded; upper antennular
flagellum short, thick, curved backward; fused
part with six or seven joints; short ramus with
two joints. Antennal scale with convex outer
margin ending in small inwardly curved distal
tooth, lamella far exceeding tooth.

First leg with half or more than half of carpus
reaching beyond antennal scale; fingers longer
than palm, unarmed; carpus longer than merus.
Second legs unequal in size but similar in shape.
Larger leg with fingers a little over half length
of palm; palm twice as long as deep, somewhat
inflated; dactyl narrower than immovable finger
and bearing one large tooth slightly behind mid-
dle; cutting edge of immovable finger with two
large teeth fitting on each side of opposed dactylar

FISH AND WILDLIFE SERVICE

Figure 40. — Pontonia marga/rita Smith. A, anterior part
of carapace in lateral view. X 11.5 ; B, anterior part of
body in dorsal view, X 11.5; C, first leg, X 5.9; D,
larger second leg, X 6; E, smaller second leg, X 6 ; F,
third leg, x 9-5 ; G, dactyl of third leg, X 35 ; H, telson
in dorsal view, X 11.5 (after Holthuis, 1951a).

tooth and separated by a hole on inner side of edge,
posterior tootli with denticles at apex; carpus
shorter than merus, conical. Smaller second leg
resembling larger except for relatively longer
fingers. Dactyls of last three walking legs
bifurcate.

Abdomen with pleura of first five segments
broadly rounded, of sixth ending in a strong spine
overlapping base of uropods. Sixth segment a
little more than half length of telson. Telson with
two pairs of large dorsal spines placed laterally,
and at one-third and two-thirds of length; pos-
terior border with three pairs of spines in a row,
inner two pairs equal, outer pair smaller. Uropods
broadly ovate, exopods ending in a minute mov-
able spine on outer margin.

Measurements. — Length of body : male, 19 mm. ;
ovigerous females, 17 to 27 mm.

Color. — Glassy, translucent ; internal organs
clearly visible; ovigerous females with two colors
of eggs, one with light, muddy green eggs and
ovarian ova of same color, another with pale
orange eggs (from specimens taken in Aequipec-
ten gibbiis off Drum Inlet, N.C., in 20-fathom
water, April 14, 1960).

Habitat. — The species lives commensally in
lamellibranch mollusks in coastal waters. It has
been found in Aequipecten gibbus and Pteria
colymbus in North Carolina, and in the pearl
oyster Pinctada fitnbriata on the west American
coast; tidal flats to 33 fathoms.

Type locality. — Bay of Panama.

Known range. — Atlantic coast: Drum Inlet to
Beaufort Inlet, N.C.; east and west Florida.
Pacific coast : Gulf of California to Colombia ;
Galapagos Islands.

Remarks. — Ovigerous females have been taken
in North Carolina in January and April.

Genus Neopontonides Holthuis, 1951

Holthuis. 1951a, p. 189.

Neopontonides beaufortensis (Borradaile)

Figure 41

Periclimenes beaufortensis Borradaile, 1920, p. 132.
Neopontonides beaufortensis: Holthuis, 1951a, p. 190, pi. 59,
figs, g-k ; pi. 60, figs, a-k (rev.).

Recognition characters. — Rostrum slender,
straight; a little shorter than antennular pe-
duncle; laterally compressed but broadened at
base, covering eyestalks, lateral margin of widened
base not merging with obital margin; upper
margin with none to five teeth, most proximal
teeth, when present, in front of posterior margin
of orbit on a crest, crest remaining visible in
absence of teeth; lower margin unarmed. Cara-
pace smooth or somewhat areolated; anterior
margin of carapace with lower angle of orbit
produced in a rounded lobe ; antennal spine strong,
located considerably below oi'bit; a rounded lobe
slightly below antennal spine followed by an
emargination ending in a produced anterolateral
angle; hepatic and supraorbital spines absent.
Eyes large, reaching almost to end of rostrum.
Basal article of antennular peduncle with sty-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure 41. — Neopontonides beaufortensis (Borradaile).
A, anterior part of body in dorsal view, X 19.5; B, an-
terior part of body in lateral view, X 13 ; O, antennule,
X 26 ; D, antennal scale, X 26 ; E, first leg, X 39 ; F,
smaller second leg, X 26; G, larger second leg, X 26;
H, fingers of larger second leg, X 65; I, third leg, X 26
(after Holthuis, 1951a).

locerite rather broad, ending in slender point
reaching almost to middle of article; outer margin
of article slightly concave ending in strong an-
terolateral spine reaching end of second article;
upper antennular flagellum with rami fused for
two to four joints; short ramus with two to four
free joints. Antennal scale reaching beyond an-
tennular peduncle; concave outer margin ending
in strong tooth; lamella exceeding tooth; a small
lateral tooth at base; antennal peduncle reaching
about to middle of scale.

First leg reaching beyond end of antennal
scale ; fingers slightly shorter than palm, unarmed,
slightly agape; carpus about as long as merus.
Second legs unequal. Part of palm of larger leg
exceeding antennal scale; fingers half or less
length of palm, dactyl with two, immovable finger
with one tooth on cutting edge; palm slightly
swollen ; carpus short, conical ; merus about twice
length of carpus. Smaller second leg with fingers
as long as palm, slender, unarmed ; carpus nearly
as long as palm. Third leg with heavy, simple
dactyl.

Abdomen smooth, all pleura broadly rounded.
Sixth segment as long as telson. Telson with two
pairs of dorsolateral spines; posterior pair mid-
way between anterior pair and tip; three pairs
of spines on posterior border, intermediate pair
less than twice length of inner pair. Uropods
elongate; outer margin of exopod ending in a
tooth flanked medially by a movable spine.

Measurements. — Length of body: male, 9 mm.;
ovigerous females, 7 to 9 mm.

Variations. — In young specimens, the legs are
relatively shorter than in adults, and the larger
second leg resembles the smaller second leg of
adults.

Color. — Nearly transparent, but with faint col-
oration of Leptogorgia from which individuals
are taken (yellow or orange).

Habitat. — This species is found in coastal
waters where it lives in association with
Leptogorgia; surface to a few fathoms.

Type locality. — Beaufort, N.C.

Knoxon range. — Beaufort, N.C, to Grand Isle,
La. (Dawson, 1963); Caledonia Bay, Panama;
Antigua.

Remarks. — Ovigerous females have been taken
in Bogue Sound near Beaufort Inlet, N.C, in
August and November, in Panama in April, and
in Antigua in May.

Subfamily Palaemoninae

Upper antennular flagellum with both rami
fused in basal part. Appendix masculina gen-
erally present on second pleopod of male, appen-
dix interna on second pleopod of female. Pleuro-
branch present on third maxilliped. Posterior
margin of telson with two pairs of spines and one
or more pairs of setae ( I Iolthuis, 1952).

FISH AND WILDLIFE SERVICE

KEY TO GENERA AND SPECIES IN THE CAROLINAS

(Holthuis, 1952, modified)
a. Hepatic spine present, branchiostegal spine absent ;
chelate second legs enlarged and greatly elongated,
b. Dactyls of last three legs bifurcate ; marine

Braehycarpus biitngiiiciilatus (p. 51).
bb. Dactyls of last three legs simple ; fresh or brackish

water Macrobrachium (p. 52).

c. Fingers of chelae on second legs thickly pubescent
throughout length ; rostrum with teeth extending

up to tip M. acanthurus (p. 52).

cc. Fingers of chelae on second legs with scattered
hairs, except thicker on ringers along cutting edges ;
rostrum with toothless daggerlike tip

M. ohione (p. 54).
aa. Hepatic spine absent, branchiostegal spine present;
chelate second legs not greatly enlarged.

b. Mandible with a palp Leander tcnuieornis (p. 55).

bb. Mandible without a palp Palaemonctcs (p. 56).

c. Carpus of second leg in adult female shorter than
palm, in males slightly longer or shorter (1.1
times) than palm; dactyl of second leg with two,
immovable finger with one tooth on cutting edge ;
rostrum with first two teeth of dorsal margin
behind orbit, dorsal rostral teeth reaching to apex,

lower margin with three to five teeth

P. vulgaris (p. 56).

cc. Carpus of second leg in adult female much longer

than palm (1.3 to 1.5 times), in males almost as

long as whole chela ; dactyl of second leg with a

single tooth or without teeth, immovable finger

without teeth on cutting edge ; rostrum with only

one dorsal tooth behind orbit.

d. Dorsal teeth of rostrum reaching up to apex,

apex often bifurcate ; lower margin of rostrum

with four or five, seldom three teeth ; dactyl of

second leg with one distinct tooth on cutting

edge P. intermedins (p. 58).

dd. Dorsal and ventral margins of rostrum with an
unarmed stretch before dagger-shaped tip ; lower
margin of rostrum with two to four, generally
three, teeth ; fingers of second leg without teeth
on cutting edges P. pugio (p. 59).

Genus Braehycarpus Bate, 1888

Holthuis, 1952, p. 2.— Hemming, 1958b, p. 154.

Figure 42. — Braehycarpus biunguiculatus (Lucas). A,
carapace in lateral view, X 6 ; B, antennule, X 7 ; C,
antenna, X 7 ; D, first leg, X 6 ; E, left second leg, X 6 ;
F, right second leg, X 6 ; G, third leg, X 6 ; H, dactyl
of third leg, X 16; I, telson, X 15 (after Schmitt, 1939).

Braehycarpus biungiuculatus (Lucas)

Figure 42

Palaemon biunguiculatus Lucas. 1849, p. 45, pi. 4, fig. 4.
Braehycarpus biunguiculatus: Holthuis, 1952, p. 3, pi. 1, figs.
a-q (rev.).

Recognition characters. — Rostrum well de-
veloped, rather high, directed straight forward,
reaching about to end of antennal scale; upper
margin with seven (seldom eight) teeth, first two
teeth placed behind orbit with first tooth at about

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

midlength of carapace; lower margin with three
(seldom two or four) teeth. Carapace smooth;
antennal and hepatic spines present; a strong
postorbital ridge paralleling orbit. Eyes well de-
veloped. Basal article of antennular peduncle
with anterolateral spine strong, reaching beyond
second article of peduncle ; stylocerite small, acute,
closely appressed to article; rami of inner anten-
nular flagellum fused for 8 to 23 joints; free part

of shorter ramus about as long as fused portion.
Antennal scale about three times longer than
broad, outer margin concave, terminal spine over-
reaching lamella.

First legs slender ; fingers of chelae longer than
palm ; carpus longer than chela. Second legs much
stronger than first; smooth; part of carpus ex-
tending beyond antennal scale; fingers slightly
shorter than palm, but in adult males sometimes
only half length of palm, cutting edge of dactyl
with two to four, immovable finger with two
small teeth in proximal part, adult males with
fingers widely agape, opening hairy; carpus short,
cup-shaped, half length of merus. Last three legs
slender, dactyls bifurcate, propodi with spines
present on posterior margin.

Abdomen smooth, pleura of fourth and fifth
segments pointed. Telson with two pairs of dorsal
and two pairs of posterior spines; numerous setae
between inner posterior spines. Appendix interna
present on first pleopods in males, missing in
females.

Measurements. — Length of body : 65 mm.
(Holthuis, 1952).

Variations.- — Dorsal spines on the telson are
sometimes not placed in symmetrical pairs and
may be asymmetrically doubled.

Color. — Living individuals : body dark blue
green mottled with white: palm of chela uniform
blue green, fingers barred; fringes of antennules,
antennae, antennal scale and tail fan orange;
some individuals colorless, with tawny-tinged
spots. Preserved specimens: pale brownish yel-
low, tips of fingers brownish red preceded by
colorless band, then a fainter band of brownish
red; antennular flagella red with white rings at
articulations between joints (Holthuis, 1952).

Habitat. — Found near shore among corals or
rocks, and on sea buoys; surface to 4 fathoms.

Type locality. — Oran and Bone, Algeria.

Known range. — Virtually pantropical; East
and West American coasts, Mediterranean; West
Africa; and Indo-Pacific region. Western Atlan-
tic distribution: Cape Fear, NX1., through AVest
Indies to Curacao and Old Providence. Island;
Bermuda.

Remarks. — Gurney and Lebour (1941) de-
scribed a complete series of 11 larval stages and

a postlarval stage of this species from Bermuda.
They pointed out that the larval life of this form
may be indefinite in length and number of de-
velopmental stages, and that this feature of
development may account for the wide distribu-
tion of the species. Gurney (1943a) noted pro-
portional changes in growth of the segments of
the second legs in the last larval stage, first post-
larval stage, and adult female.

Genus Macrobrachium Bate, 1888

Holthuis, 1952, p. 10.

Macrobrachium acanthurus (Wiegmann)

Figures 43-44

Palaemon acanthrus Wiegmann, 1836, p. 150.
Macrobrachium acanthurus: Holthuis, 1952, p. 45, pi. 9, figs.
a-b (rev.),

Recognition characters. — Rostrum almost
straight, reaching slightly beyond antennal scale ;
upper margin slightly arched basally, with 9-11
teeth, proximals closer together than distals, first 2
teeth on carapace behind orbit, second tooth some-
times partly over posterior margin of orbit and
separated from first tooth by distance greater
than that between other proximal teeth: lower
margin with 4 to 7 (generally 6) teeth, proximals
closer together than distals. Carapace smooth,
with short hairs especially on anterolateral region ;
antennal spine a little below orbit and slightly
removed from margin; hepatic spine behind and
a little below antennal spine. Antennal scale about
three times longer than broad; outer margin
straight or convex.

First legs with chela and sometimes part of
carpus reaching beyond scale; fingers as long as
palm; carpus one-third longer than merus. Sec-
ond legs equal, with carpus and sometimes part
of merus reaching beyond scale; fingers slender,
thickly pubescent throughout length, slightly
shorter than palm, cutting edges with a tooth on
each finger in proximal quarter (that of dactyl
more advanced) preceded by row of about four
denticles; palm elongate, cylindrical, with several
longitudinal rows of spinules largest and widest
apart on inner and lower regions; carpus and
merus spinulose like palm. Articles of last three
walking legs with numerous densely placed small
spinules.

FISH AND WILDLIFE SERVICE

Figure 43. — Maorohraohium acanthurus (Wiegmann). Animal in lateral view (after Hedgpeth, 1949).

Abdomen smooth; pleura of fifth segment end-
ing in an acute point. Telson 1.5 times length
of sixth segment, with pairs of dorsal spines at
middle and three-fourths of length; posterior
margin ending in sharp median point flanked by
two pairs of spinules, inner pair overreaching
median point.

Measurements. — Length of body : male, 166
mm.: ovigerous females, 36 to 110 mm.

Figure 44. — Macrobrachium acanthurus (Wiegmann).
A, second leg of adult male; B, fingers of second leg
of adult male (part of hairs removed) : A, B, X 0.75
(after Holthuis, 1952).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
T63M)49 O — 65 — —5

Variations. — The rostrum may vary in length
and shape. Adult females and young males have
second legs shorter, more slender, less spinulose
and pubescent than adult males.

Color. — Green or pale yellow with red speckles;
carapace with middorsal stripe of red or brownish
orange and occasionally with irregular red bands
laterally; chelipeds greenish becoming blue dis-
tally, articulations orange; abdomen with mid-
dorsal stripe similar to carapace, pleura green
with blue edges and striped with red ; eggs green
(Hedgpeth, 1949; Schmitt in Holthuis, 1952).

Habitat. — The species lives in coastal rivers
and bays, usually near brackish water, but some-
times quite far upstream; 97 miles from mouth
of Rio Grande River in Texas (Hedgpeth, 1949).

Type locality. — Brazilian coast.

Known, range. — Neuse River estuary, N.C., to
Rio Grande do Sul, Brazil; West Indies.

Remarks.— This species probably has a later
breeding season than Macrobrachivm ohione
(Hedgpeth, 1949). The recent discovery of M.
acanthurus in the Neuse River estuary of North
Carolina may indicate an active northward ex-
tension of range similar to the case of M. ohione.

Macrobrachium ohione (Smith)

Figure 45

Palaemon Ohionis Smith, 1874, p. 640.

Macrobrachium ohione: Holthuis, 1952, p. 62, pi. 14, fig.
b (rev.).

Recognition characters. — Rostrum high and
straight, tip curving somewhat upward and reach-
ing to between end of antennular peduncle and
end of antennal scale; upper margin with 9 to 13
teeth, 3 or 4 teeth behind orbit, first 3 more widely
separated than remainder; lower margin with 1
to 3 teeth; distal two-fifths of rostrum unarmed.
Carapace smooth; antennal spine slightly remote
from anterior margin; hepatic spine below an-
tennal spine. Antennal scale about 2.5 times
longer than broad; outer margin straight or
slightly concave.

First legs with chelae reaching beyond scale;
chelae slender; fingers about as long as palm;
carpus twice length of chela. Second legs in adult
female stronger than in male, with carpus and
chela reaching beyond scale; fingers somewhat
shorter than palm, cutting edges pubescent and

with four to eight small denticles of equal size
on proximal half, remainder of surface with scat-
tered hairs; palm elongate, cylindrical, entirely
pubescent, most conspicuous pubescence along
lower surface; carpus, merus, and palm of equal
length, these articles and fingers with longitudinal
rows of small spinules; carpus most pubescent
anteroventrally; merus somewhat pubescent an-
teroventrally.

Abdomen smooth ; pleura of fifth segment end-
ing in acute point. Telson about 1.5 times length
of sixth segment; pairs of dorsal spines at mid-
dle and three- fourths of length; posterior margin
ending in an acute tip overreached by inner pair
of posterior spines.

Measurements. — Length of body : male, 68 mm. ;
female, 102 mm.

Variations. — Juveniles (10 mm. and larger)
have the same number of rostral spines as adults
but fewer spines behind the orbit. In such
juveniles, the hepatic spine is very close to the
anterior margin of the carapace, similar in posi-
tion to a branchiostegal spine.

Figure 45. Macrobrachium ohione (Smith). A, animal in lateral view (after Hedgpeth, 1!M9) ; B. second leg

of adult male (after Holthuis, 1!>T>2).

FISH AND WILDLIFE SERVICE

Color. — Pale gray flecked with small blue spots ;
uropods pale blue (Hedgpeth, 1949).

Habitat. — This species lives in rivers and
estuaries.

Type locality. — Ohio Kiver at Cannelton, Ind.

Known range. — A narrow zone along Atlantic
seaboard from James River, Hopewell, Va.
(Hobbs and Massmann, 1952), to southern
Georgia; widespread from coastal Alabama to
Aransas Bay, Tex.; Mississippi River and tribu-
taries upstream to McCurtain County, Okla. ;
Fort Smith, Ark.; St. Louis, Mo.; Washington
County, Ohio.

Remarks. — This species is distributed chiefly in
brackish and fresh water, ranging far inland in
the Mississippi River drainage. It is abundant
enough, especially in Louisiana, to provide a
fishery of some importance though the exact mag-
nitude is not known. Gunter (1937) described
the Louisiana fishery and gave information on
ecology of the species. Commercially, the shrimp
are taken in traps made of. wooden slats, similar
to lobster traps, baited with meat scraps or cotton-
seed cake. The shrimp are sometimes captured
by lifting submerged willow branches from the
water and catching the animals as they drop off.
Such catches are best made at night. Commer-
cial shrimping is done in the warmer months, as
the animals are scarce in winter. The shrimp
will attack fish kept in live boxes in the river, and,
though the feeding habits of the species are not
known completely, the animals are thought to
be primarily carnivorous.

During a period of study from November to
early July, Gunter found that ovigerous females
first appeared in mid- April, and egg-bearing fe-
males were still present when the work was ter-
minated in July. Ovigerous females have been
found in April and May in North Carolina.
McCormick (1934) stated that eggs in various
stages of development were found in females at
the same time that thqy were in berry, which
indicates a long egg-laying season. Gunter found
females to outnumber males by more than 3 to
1. However, this ratio varied. When females were
carrying eggs, males made up only 9 percent of
the captured individuals, but prior to the egg-
laying season males made up 31.8 percent of the
total. He concluded that this indicated a change
in sex ratio at the egg-bearing period.

Thirteen percent of the females caught were
ovigerous, and these ranged in length from 38 to
76 mm. Eggless females ranged from 23 to 93
mm. in length. From November to December, the
population was made up of individuals 60-80 mm.
long. In January, shrimp below 30 mm. average
length predominated, but from then until April
the average length increased to about 50 mm., and
thereafter the range of variation widened as
smaller animals came into the catch.

Gunter found ovigerous females in bay water
with salinities ranging from 1.38 to 14.24 °/00.
He noted that when the river was on a rise, with
turbidity high, few shrimp were taken in water
over 20 feet deep, and these were sometimes dead.
He conjectured that because these shrimp were
not buried in mud, high turbidity in deep water
during flood may have an adverse effect on respira-
tion. Hedgpeth (1949) suggested that silt causing
interference with respiration may drive the
shrimp from rivers to estuaries during such
seasons, but he also suggested that in regions
such as the Atlantic seaboard, where the species
is apparently a comparatively recent immigrant,
it may still depend on bay waters to complete its
breeding cycle. In any case, it is thought that
these shrimp and other species of the genus move
from river to river through the salty estuaries
at the river mouths (Gunter, 1937).

Especially interesting is the fact that this
species and M. acanthurus are forms which may
be advanced in the process of moving from the
sea to fresh water. Few such examples exist.

Genus Leander Desmarest, 1849

Holthuis, 1952, p. 167.

Leander tenuicornis (Say)

Figure 46

Palaemon tenuicornis Say, 1818, p. 249. — Hay and Shore, 1918,
p. 392, pi. 27, fig. 6.

Leander tenuicornis: Holthuis, 1952, p. 155, pi. 41, figs, a-g ;
pi. 42, figs, a-f (rev.).

Recognition characters. — Rostrum well devel-
oped ; high in female, more slender in male ; reach-
ing about to end of antennal scale; upper margin
with 8 to 14 regularly spaced teeth, first two
behind orbit; lower margin with 5 to 7 teeth
partially concealed by double row of setae.
Carapace smooth; antennal spine present, and a
branchiostegal spine placed some distance behind
anterior margin; branchiostegal groove absent.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure 46. — Leander tenuicoi-nis (Say). A, anterior part
of body of female in lateral view ; B, anterior part of
carapace of male in lateral view; C, antennule: D,
antennal scale: E, first leg: F, second leg: G. third leg:
II. fifth leg (after Holthuis, 1952).

Eyes well developed, rounded; two dark-colored
bands visible on cornea, especially in fresh mate-
rial. Basal article of antennule with stylocerite
large and pointed, reaching beyond middle of
article, and with anterolateral spine reaching al-
most to end of second article of peduncle, anterior
margin of basal article between spine and second
article straight or only slightly convex; second
and third antennular articles shorter and narrower
than first; upper flagellum with fused portion of
rami shorter than free portion of shorter ramus.
Antennal scale 3 to 5 times longer than broad;
outer margin about straight; terminal tooth
strong, as long as lamella: antennal peduncle not
reaching middle of scale; a strong external spine
near base of scale- Mandible with :i two-jointed
palp.

First pair of legs slender; reaching about to
end of scale; lingers longer than palm. Second
legs more robust than first, equal in size and
shape; chelae reaching beyond scale; linjrers
longer than slightly swollen palm, cutting edges
of fingers entire excepl Eoi small basal tooth in
males; carpus shorter than chela and about as

long as merus. Last three legs slender, dactyls
simple, slender: propodi armed with posterior
spinules ; fifth leg more slender than third.

Abdomen smooth; first three pleura broadly
rounded; pleura of fourth and fifth segments
narrower, ending in a minute, acute tooth. Sixth
segment slightly longer than fifth and about two-
thirds length of telson. Telson with two pairs of
dorsal spines, first pair at midlength, second at
three-fourths length; inner of two pairs of pos-
terior spines overreaching acute tip of telson, a
pair of strong feathered setae between inner pair
of spines.

Measurements. — Length of body : 47 mm. ;
males generally smaller than females; ovigerous
females 26 mm. long have been reported
(Holthuis, 1952).

Variations. — Length of the second legs is
variable, and the palm of the chela is more swollen
in some specimens than in others. Length of the
terminal tooth of the antennal scale is variable.

Color. — Green or olive, with opaque spots
(Schmitt in Holthuis, 1052, for specimens from
Tortugas).

Habitat. — Found in floating sargassum, on
wharf pilings, and among submerged vegetation.

Type locality. — Newfoundland Banks.

Known range. — Tropical and subtropical waters
all over world except for west coast of Americas;
Newfoundland Banks to Falkland Islands in
western Atlantic (Holthuis, 1952).

Remarks. — Ovigerous females have been ob-
served from July to October in the Carolinas, in
June in the middle and western Atlantic (Sivert-
sen and Holthuis, 1956), and in August at Old
Providence Island (Schmitt, 1939). Gurney
(1939) described the fifth(?) larval and first
postlarval stages and compared them to related
forms, with remarks on the statocyst in adults.

Genus Palaemonetes Heller, 1869

Holthuis, 1952, p. 199. Hemming. 1958b, |> 158

Subgenus Palaemonetes Heller

Holthuis. 1952. p. 207.

Palaemonetes (Palaemonetes) vulgaris (Say)

Figure 47

Palaemon oulgarit Say. 1S18, p. 248.

Palaemonetes carolinut: Hay and Shore, 1918. p. 393. pi. 27,

tig. 4.

Palaemonete* (Palaemonetee) vulgaris: Holthuis. 19ri2. p. 231.
pi. 54, figs, f-1 (rev.).

:,«»

FISH AND WILDLIFE SERVICE

Recognition characters. — Rostrum reaching to
or slightly beyond end of antennal scale; tip di-
rected upward making upper margin more or less
concave; upper margin with 8 to 11 teeth, first
2 teeth behind orbital margin and separated more
widely than other proximal teeth, all teeth rather
regularly distributed along rostrum but proximals
generally closer together than distals, no unarmed
space behind tip, tip often bifurcate; lower mar-
gin with 3 to 5 (usually -1) teeth. Carapace
smooth; antennal spine present; branchiostegal
spine on anterior margin just below branchiostegal
groove. Eyes well developed. Basal article of
antennular peduncle with slender stylocerite
reaching slightly beyond middle of article,
anterolateral spine of article strong, overreaching
rounded anterior margin; upper antennular
flagellum with both rami fused for 7 to 9 joints;
free part of shorter ramus with 10 to 17 joints, at
least 1.5 times as long as fused portion. Antennal
scale 3 times longer than broad; terminal tooth
strong, reaching almost to end of lamella.

Figure 47. — Palaemonetes (Palaemonetes) vulgaris
(Say). A. anterior part of body in lateral yiew : B.
antennnle ; C, antennal scale : D, second leg of female :
E, fingers of second leg of female : F. second leg of
male; G, third leg: A-G X 5 (after Holthuis, 1952).

First leg usually not reaching to end of anten-
nal scale; fingers about as long as palm; carpus
1.3 to 1.7 times as long as chela and a little longer
than merits. Second legs longer and stronger
than first, stronger in adult females than in males
with fingers and sometimes entire palm reaching
beyond scale; fingers a little over half length of
palm, cutting edge of dactyl with two small teeth
proximally, immovable finger with one similar
tooth fitting between those of dactyl; carpus
shorter than palm and about three-fourths length
of merus. Second legs of male not so large as in
female; teeth on fingers indistinct. Third leg
with propodus less than twice length of carpus.
Fifth leg with propodus about three times length
of dactyl, twice as long as carpus.

Abdomen smooth; fifth segment with tip of
pleura rectangular or slightly acute. Sixth seg-
ment 1.5 times length of fifth, shorter than telson.
Telson with two pairs of dorsal spines; anterior
pair somewhat behind middle; second pair half-
way between these and tip ; posterior margin with
strong median point flanked by two pairs of
spines, inner pair longest and between them two
feathered setae. Outer margin of uropodal exopod
with a strong terminal tooth flanked by a slender
movable spine medially.

Measurements. — Length of body : male, 30 mm. ;
ovigerous females, 22 to 42 mm.

Color. — Transparent in life.

Habitat. — Estuarine waters, especially in beds
of submerged vegetation; water's edge to (rarely)
S fathoms. Salinity of 3°/00 is apparently lethal
(Nagabhushanam, 1961).

Type locality. — Atlantic coast of United States.

Known range. — Barnstable County, Mass., to
Cameron County, Tex. (from specimens exam-
ined by Holthuis, 1952). Literature records:
Gaspe, Quebec, Canada, to Rio Champoton and
near Progreso. Yucatan, Mexico (Holthuis, 1952).

Remarks. — Correct identification of the species
of Palaemonetes occurring on the east coast of
the United States was not possible until Holthuis
(1949) introduced his key. As Holthuis (1952)
pointed out, two names, vulgaris and carolinus,
were applied indiscriminately to three species but
the description of carolinus was actually based on
a specimen of vulgans ; hence, this name is a syno-
nym of vulgaris. With the status of vulgaris
stabilized, Holthuis went on to show that two

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

other closely related and newly described species,
intermedins and pugio, occupy much the same
habitat and geographic range as vulgaris. An
unfortunate but natural result of such confusion
is that the voluminous literature on "vulgaris"
undoubtedly concerns all three species in unknown
ways, and all such literature must now be viewed
with reserve.

Jenner (1955) showed that in the Woods Hole,
Mass., region, where much of the experimental
work on Palaemonetes has been done, both P.
vulgaris and P. pugio occur. He showed that a
useful field character for differentiating these two
species is color of the eyestalks, the eyestalks of
P. pugio being generally much more yellow than
those of P. vulgaris, the latter being more red
brown. The source of Palaemonetes for the
Marine Biological Laboratory is thought to have
been principally from the dock where only P.
vulgaris has been found ; hence, Jenner suggested
that most of the experimental work at Woods
Hole has been correctly referred to P. vulgaris.
In North Carolina, these eye-color differences are
less apparent.

The breeding season for the species in Virginia
and the Carolinas extends from April to mid-
October. Larval stages of P. vulgaris have been
described by Broad (1957a) and are summarized
below under the account for P. pugio.

Burkenroad (1947a) showed that male P. vul-
garis respond only to females which have molted
to breeding form recently. After mating, the
female resists further courtship. Males recognize
such females only upon contact of the antennae
with any surface of the female. The sperma-
tophore will adhere to any part of the integument
of either sex, but becomes nonadhesive almost
immediately after exposure. Burkenroad stated
that the sperm-bearing matrix of the spermato-
phore dissolves about a half hour or less before
spawning, and he thought that some substance
liccing the sperm cells must be released by the
female at the approach of spawning.

Eggs are released simultaneously from both
oviducts in a continuous stream. Fertilization is
external and, because sperm cells of decapod
crustaceans in general are nonmotile, it was sug-
gested that entry of the sperm cell precedes de-
velopment of the egg membranes in all decapods.

All parts of the eggshell are produced by the ovum
or the embryo. The first membrane is developed
upon contact with water. The second is developed
about half an hour after spawning, and the third
about 12 hours after spawning in fertile eggs
only. The fourth and last membrane is an
embryonic molt skin.

In Palaemonetes, the eggs are not adhesive when
laid and first adhere to each other about half an
hour after spawning. No attachment surface other
than the first membrane of the egg develops. The
eggs become fused, apparently by their own mem-
branes, to the special setae in the brood pouch of
the female. Egg stalks are drawn out by stretch-
ing movements of the pleopods. It is possible
that the membrane is activated to become ad-
hesive by the secretion of an enzymelike material
released among the eggs by the mother from the
pleopodal glands during attachment. Only near
sources of this secretion would such attachment
occur; therefore, the eggs usually do not stick
to each other but rather to the setae.

Since the early 1930's much experimental work
has been done on the endocrine system in relation
to color control in Palaemonetes assumed to be
vulgaris. The shrimp has been found to have four
kinds of pigment under independent hormonal
control — red, yellow, white, and blue. These pig-
ments are mediated through the eyes by the back-
ground on which the animal is found. The source
of the hormones is principally the sinus gland in
the eyestalk and the central nervous organs
(Brown, 1933, 1935a, 1935b, 1948; Brown, Finger-
man, and Hines, 1952 ; Brown, Hines, and Finger-
man, 1952; Brown, Webb, and Sandeen, 1952).
Persons interested are referred to the source
material, for the conclusions are too detailed for
adequate summary here.

Palaemonetes (Palaemonetes) intermedins Holthuis

Figure 48

Palaemonetes (Palaemonetes) intermedins Holthuis, 1949, p.
94. tig. 2, J-l. — Holthuis, 1952, p. 241, pi, 55, figs, a-f (rev.).

Recognition characters. — Rostrum reaching to
or somewhat beyond end of antennal scale, tip
directed upward making upper margin more or
less concave; upper margin with 7 to 10 (usually
8 or 9) teeth, first tooth placed behind orbital
margin, second tooth before or just over posterior
orbital margin; teeth rather evenly divided over

FISH AND WILDLIFE SERVICE

Figure 48. — Palaemonetes {Palaemonetes) intermedins
Holthuis. A, anterior part of body in lateral view; B,
antennule ; C, antennal scale ; D, second leg of female ;
E, fingers of second leg of female; F, third leg; A-F
X 4.75 (after Holthuis, 1952).

dorsal margin up to often bifurcate tip, distal
teeth more widely spaced than proximals; lower
margin with 4 or 5 (occasionally 3) teeth. Cara-
pace smooth; antennal spine present; branchioste-
gal spine on anterior margin just below bran-
chiostegal groove. Eyes well developed. Anten-
nular peduncle as in vulgaris, basal article with
slender stylocerite reaching about to middle of
article, anterolateral spine of article strong, over-
reaching rounded anterior margin; upper anten-
nular flagellum with both rami fused for 7 to
10 joints; free part of shorter ramus with 7 to
12 joints, longer than fused portion. Antennal
scale slender, 3 to nearly 4 times as long as broad
in females, even more slender in males; outer
margin straight or slightly concave; terminal
tooth reaching about to end of lamella.

First legs almost reaching tip of antennal scale ;
fingers as long as palm; carpus twice length of
chela and slightly longer than merus. Second legs
in adult female usually with almost entire chela
reaching beyond antennal scale; fingers a little
over half length of palm, cutting edge of dactyl
with one proximal tooth, remainder of cutting
edges of both fingers entire; carpus 1.2 to 1.5
times length of palm and as long as merus. Sec-
ond leg of male somewhat more slender than in
female ; only fingers reaching beyond scale ; carpus

as long as merus. Third leg with propodus less
than twice as long as carpus. Fifth leg with
propodus about three times as long as dactyl,
twice as long as carpus.

Abdomen smooth; pleura of fifth segment with
tip rectangular or slightly acute; sixth segment
1.5 times length of fifth, somewhat shorter than
telson. Telson with two pairs of dorsal spines;
anterior pair somewhat behind middle; second
pair halfway between these and tip; posterior
margin with strong median point flanked by two
pairs of spines, inner pair longest and between
these, two feathered setae. Outer margin of
uropodal exopod with a strong terminal tooth
flanked by a slender movable spine medially.

Measurements. — Length of body : male, 30 mm. ;
ovigerous females, 20 to 42 mm.

Variations. — In males and juveniles, the legs
reach less far forward than in ovigerous females
(Holthuis, 1952). The second chelae of some fe-
males have one tooth on the cutting edge of each
finger.

Color. — Transparent in life.

Habitat. — Estuarine waters, especially in beds
of submerged vegetation.

Type locality. — Iron Box Bay, Chincoteague
Bay, Va.

Known range. — Long Island, N.Y., to Port
Aransas, Tex. (from specimens examined by
Holthuis, 1952). Literature records: Vineyard
Sound to Aransas National Wildlife Refuge, Tex.
(Holthuis, 1952).

Remarks. — The confused taxonomic status of
this species in literature is discussed in the account
for P. vulgaris and dealt with in more detail by
Holthuis (1952). Ovigerous females have been
found from February to April in Texas (Hedg-
peth, 1950), and from May to September in
Virginia and the Carolinas.

Palaemonetes (Palaemonetes) pugio Holthuis

Figure 49

Palaemonetes vulgaris: Hay and Shore, 1918, p. 393, pi. 27,
fig. 5.

Palaemonetes {Palaemonetes) pugio Holthuis, 1949, p. 95, figs.
2, m-o.^Holthuls, 1952, p. 244, pi. 55, figs, g-1 (rev.).

Recognition characters.- — Rostrum reaching to
or slightly beyond end of antennal scale ; straight,
sometimes slightly upturned at tip; dorsal mar-
gin with 7 to 10 (usually 8 or 9) teeth, distal teeth
more widely spaced than proximal teeth, first

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figure V.K — Palaenwnctes i Palaemonetes i pugio Holthuis.
A, anterior part of body in lateral view; B, antennule;
C, antennal scale; 1), second leg of female; E, fingers
of second leg of female: F, third leg; A-F X 4.75 (after
Holthuis, 1952).

tooth placed behind orbital margin, distal tooth
placed at a distance from tip leaving space be-
fore tip unarmed; lower margin with 2 to 4
(usually 3) teeth, distal tooth also placed at
distance from tip, tip dagger shaped. Carapace
smooth; antennal spine present; branchiostegal
spine on anterior margin just below branchiostegal
groove. Eyes well developed. Antennular pe-
duncle as in vulgaris; basal article with slender
stj'locerite reaching slightly beyond middle of
article, anterolateral spine of article strong, over-
reaching rounded anterior margin; upper anten-
nular flagellum with both rami fused for 10 to
14 joints; free part of shorter ramus with 12
to 18 joints, longer than fused portion. Anten-
nal scale 2.5 to 3 times longer than broad (length
.'5 times breadth in males) ; outer margin convex;
terminal tooth strong, almost reaching end of
lamella.

First legs not quite reaching tip of antennal
scale ; fingers as long as palm ; carpus nearly t wice
length of chela and slightly longer than merus.
Second legs stronger than first; in adult female.
fingers reaching beyond scale, lingers more than
half length of palm, cutting edges of both lingers

with no teeth, often gaping proximally; carpus
1.3-1.5 times length of palm but shorter than
entire chela; merus as long as carpus. Male with
second legs more slender and shorter than in fe-
male ; fingers shorter than palm ; carpus nearly as
long as whole chela and as long as merus. Third
legs with propodus twice length of carpus. Fifth
leg with propodus about 2 times length of dactyl,
2.5 times as long as carpus.

Abdomen smooth; fifth abdominal segment
with pleura ending in an acute tooth, sometimes
extremely small; sixth segment half again as
long as fifth, somewhat shorter than telson. Tel-
son with two pairs of dorsal spines; anterior
pair somewhat behind middle; second pair half-
way between these and tip ; posterior margin with
strong median point flanked by two pairs of
spines, inner pair longest, and between them two
feathered setae. Outer margin of uropodal exopod
with a strong terminal tooth flanked by a slender
movable spine medially.

Measurements. — Length of body : male, 33 mm. ;
ovigerous females, 30 to 50 mm.

Variations. — Males differ from females as fol-
lows : smaller size, more slender rostrum, free part
of shorter ramus of upper antennular flagellum
longer in relation to fused part, somewhat shorter
legs, and carpus of second leg longer in relation
to chela. Young individuals resemble males
(Holthuis, 1952). The second chelae of a few
females have one small tooth on the cutting edge
of the dactyl.

Color. — Transparent in life.

Habitat. — Estuarine waters, especially in beds
of submerged vegetation.

Type locality. — Lagoon near Cove Point Light,
Chesapeake Bay.

Knoion range. — Essex County, Mass., to Port
Aransas, Tex. (from specimens examined by
Holthuis, 1952). Literature records: Cold Spring
Harbor, Long Island, N.Y., to Corpus Christi,
Tex.

Remarks. — The confused taxonomic status of
this species in literature is discussed in the ac-
count for P. vulgaris and dealt with in more de-
tail by Holthuis (1952).

Broad (1957a) worked out the larval develop-
ment of P. pugio and P. ruh/aiis. He found ma-
ture individuals of both species were abundant in
the Beaufort. X.C., area from April until mid-

FISH AND WILDLIFE SERVICE

October. Larval development of the 2 species is
similar, and 10 zoeal stages and a postlarval
stage were described for both. The chief differ-
ence between larvae of the two species is in the
presence of a pair of chromatophores found on
the second abdominal sternite of P. pugio but
lacking in P. vulgaris. The number of larval
stages and length of the developmental period
may vary, and such variation is apparently due to
availability of suitable food. In rearing Palae-
m<metes with artificial diets, Broad (1957b)
found that algae alone were not sufficient to pro-
mote survival ; mixtures of plant and animal food
were better, but best survival was obtained by
feeding living Artemia nauplii. Frequency of
molting and rate of development were directly
correlated with amount of suitable food available.

Responses of the white chromatophores of
P. pugio to light and temperature have been in-
vestigated by Fingerman and Tinkle (1956). The
tendency of white pigment to disperse in bright
light, especially on a white background, is nor-
mally antagonized by a tendency of the pigment
to concentrate with increased temperature. This
mechanism is interpreted as maintaining a steady
state of white chromatophores in nature.

Pearse (1952b) reported Probopyrus pandicola
(Parkard) from the gill chamber of this species
in Texas.

Family Gnathophyllidae

Caridea with first two pairs of legs chelate,
first pair smaller than second; carpus of second
pair not subdivided. Rostrum short and toothed.
Third article of third maxillipeds very broad.
Mandibles simple. Second maxillipeds with short
seventh article. The family contains but a
single genus (Hay and Shore, 1918).

Genus Gnat hophy Hum Latreille, 1819

Armstrong, 1940, p. 6 (rev.).— Hemming, 1958b, p. 156.

Gnathophyllum modestum Hay

Figure 50

Gnathophyllum modestum Hay, 1917, p. "2. — Hay anil Shore.
1918, p. 395, pi. 28, fig. 1— Manning, 1963; p. 48, figs. 1-2.

Recognition characters. — Body short and thick ;
carapace with a moderate carina continuous in
front with rostrum and extending about two-
thirds of distance to posterior margin. Rostrum

r^T"7-- tiS-'J.'MT

'.."P

5*- ''' .

Figure 50. — Gnathophyllum modestum Hay. A, anterior
portion of carapace, lateral view ; B, antennular pe-
duncle, ventral view ; C, telson and left uropod ; D, an-
tennal scale; 1 mm. indicated, B and D to same scale
( after Manning, 1963 ) .

obliquely truncate dorsally and armed with five
or six dorsal teeth ; one or two small ventral teeth
near tip; tip reaching to distal end of basal article
of antennule. Suborbital angle prominent; anten-
nal spine present; anterolateral angle strongly
produced. Eyes rather large and with a promi-
nent, conical, black protuberance on cornea.
Antennular peduncles with basal article large,
stylocerite reaching beyond middle of article, a
spine at anterolateral corner of article; second
article with a similar but smaller and blunter
anterolateral spine; second and third articles of
about equal length; outer antennular flagellum
bifurcate, upper ramus longer and thinner than
lower ramus. Antennal scale reaching beyond
antennular peduncles, lateral margin almost

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

straight, terminating in a spine, lamella of scale
rounded distally, slightly exceeding spine.

Third maxillipeds with merus and carpus broad,
closing whole front of buccal region ; two terminal
articles flattened, much more slender, and ex-
tended straight forward. Second pair of legs
much stronger than first, exceeding rostrum by
length of chela ; fingers more than half length of
palm. Last three pairs of legs with dactyls
bifurcate.

Abdomen with last three segments abruptly
smaller than preceding segments and strongly
flexed. Telson with a pair of marginal spines at
about distal third and a minute pair near tip, tip
with median point and with three pairs of spines,
intermediate pair longest.

Measurements. — Length of ovigerous holotypic
female, 21 mm.

Color. — Body deep brown with many scattered
small yellow and a few larger orange spots; anten-
na! scale, distal portions of rostrum and tail fan
clear; orbital margins and eyestalks white; legs
grading from brown proximally through purple
to white distally but barred with purple un distal
portion of some elements; markings of yellow
below and on some articles of appendages
(Manning, 1963).

Habitat. — Found around clumps of coral and
sponges in shallow water; to 15 fathoms.

Type locality. — Beaufort, N.C.

Known range. — Beaufort, N.C. ; Biscayne Bay,
Fla.

Remarks. — This species, long known only from
Hay's type specimen, has recently been reported
from Florida (Manning, 1963). Manning re-
viewed the east American species of Gnatho-
phylhim, pointing out the close similarity of G.
modestum to the eastern Atlantic species G.
elegans, and giving detail on the importance of
color patterns in living material as diagnostic
characters in the genus. Excellent figures accom-
pany Manning's discussion.

Ovigerous females are known from Florida in
June. The date of collection for Hay's specimen
is unknown.

Family Alpheidae

Carapace smooth, with cardiac grooves; rostrum
reduced; antennal and branchiostegal spines al-
ways absent; carapace almost always projecting

over eyes {Automate excepted). Antennular base
cylindrical, basal article not longer than sum of
other two articles. Antennal scale rarely longer
than antennal peduncle. Mandible bipartite with
palp of two points. Chela of first leg predomi-
nant, always large (usually asymmetrical) ;
carpus short. Second legs weakly developed;
carpus multiarticulate. Third to fifth legs with
spinous propodi and simple or bifurcate dactyls;
propodus of fifth leg with more or less well-
developed brush of bristles in transverse to ob-
lique rows. Abdomen usually with gradual curve,
no pronounced bend at third segment; sixth seg-
ment short, broad, sexually dimorphic. (Adapted
from Banner, 1953).

The biology of snapping shrimp occurring on
the east coast of the United States has been re-
viewed by Knowlton (1960) and the reader is
referred to this unpublished but useful work for
more complete information than is included here.

KEY TO GENERA IN THE CAROLINAS

a. Eyestalks completely exposed

Aut&mate kingsleyi (p. 62).
aa. Eyestalks covered by carapace.

b. Epipods present on at least first two pairs of legs

Alpheus (p. 63).
lib. Legs without epipods Synalpheiis (p. 69).

Genus Automate de Man, 1887

Man, J. G. de, 1887, p. 529.

-Hay and Shore, 1918,

Automate kingsleyi Hay

Figure 51

Automate kingsleyi Hay, 1917, p. 72.
p. 387, text-flg. 10 ; pi. 26, fig. 7.

Recognition characters. — Carapace about half
length of abdomen; subcylindrical ; deeply emar-
ginate dorsally behind eyestalks with rostrum a
small median projection; anterior margin entire,
produced farthest forward at base of antennular
and antennal peduncles. Eyestalks contiguous,
broad at base; cornea well developed with a min-
ute point on anterior surface in lateral view.
Antennular and antennal peduncles long; stylo-
cerite scalelike, reaching to end of basal anten-
nular article; second antennular article nearly
equal in length to first ; third very short. Antennal
scale extending to middle of terminal article of
antennal peduncle; lateral border ending in a
small spine; lamella broadly rounded distally,
equaling spine. Third maxilliped exceeding an-

FISH AND WILDLIFE SERVICE

Figure 51. — Automate kingsleyi Hay. A, anterior part
of ovigerous female in lateral view ; B, anterior part of
body in dorsal view ; C, large chela ; D, uropods and
telson in dorsal view ; 1 mm. indicated ( C after Hay and
Shore, 1918).

tennal peduncle by less than length of terminal
article.

First pair of legs chelate, prismatic, unequal;
larger one appearing somewhat rougher and
stouter than smaller one ; fingers slightly gaping,
immovable finger in line with hand and broad at
base; dactyl narrower and moderately curved;
carpus short; merus nearly as long as dactyl.
Second pair of legs nearly as long as first but
slender, weakly chelate, and with carpus divided
into five joints with proportions of 1 : 1.25 : 0.80 :
0.66 : 0.80. Third to fifth legs with dactyls
simple.

Abdomen well developed; compressed; with
strong pleopods. Telson tapering; truncate ter-
minally, ending in two short lateral spines flanked
medially by two longer spines and a median pair
of feathered setae; dorsally armed with two pairs
of spines, first pair at midlength, second at
three-fourths length. Uropods with oval blades;
lateral border of exopod deeply notched distally,
border ending in a small tooth flanked medially
by a strong movable spine.

Measurements. — Length of body : ovigerous fe-
males, 7 to 16 mm.

Color. — Almost transparent except for a small
amount of red pigment on appendages and telson.

Habitat. — Unknown.

Type locality. — Shark Shoal breakwater, near
Beaufort Inlet, N.C.

Known range. — Known only from and near
type locality, and from Pelican Island, English
Harbor, Barbados (Schmitt, 1924a).

Remarks. — Aside from the Barbados specimen,
only three specimens from the Beaufort, N.C,
area are known. The ovigerous type was taken
July 9, 1916, and another ovigerous female on
September 7, 1960. The third specimen is imma-
ture. Hay and Shore (1918) reported that the
type remained alive in the laboratory for over
a month, during which time the eggs dropped off
and the specimen molted twice without appre-
ciably increasing in size.

Genus Alpheus Fabricius, 1798

Banner, 1953, p. 46. — Hemming, 195Sb, p. 108.

The status of the name Alpheus (and its confu-
sion in usage with the name Crangon, at least
among American workers during the first half
of this century) was in doubt until nomenclatural
stability was effected by the International Com-
mission on Zoological Nomenclature (Opinion
334). The Official List of Generic Names in
Zoology (Hemming, 1958b) now lists Alpheus
Fabricius, 1798, as the correct generic name for
the species here considered, and the Official Index
of Rejected and Invalid Generic Names in Zoology
(Hemming, 1958a) lists the suppressed generic
names Alpheus Weber, 1795, and Crangon Weber,
1795, formerly applied to the species here con-
sidered.

KEY TO SPECIES IN THE CAROLINAS

a. Orbital hoods of carapace with a small spine in front

forniosus (p. 64).
aa. Orbital hoods of carapace without a distinct spine,
b. Orbital hoods forming an anterior toothlike projec-
tion ; large hand with a groove above and below along
outer margin and between these grooves a thick tooth

normanni (p. 65).
bb. Orbital hoods rounded anteriorly ; large hand broad
and notched on both margins,
c. Base of rostrum passing gradually into lateral

dorsal surface heteroehaelis (p. 66).

cc. Base of rostrum with borders sharply defined

armxllatus (p. 67).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Alpheus formosus Gibbes. Striped snapping shrimp
Figure 52

Alpheus formosus Gibbes, 1850, p. 196. — Verrill, 1922, p. 84.
text-figs. 5d, 6a ; pi. 20. fig. 3 ; pi. 23, figs. 5 a, b ; pi. 29, figs. 4.
a-u ; pi. 25, figs. 6-6a.

Crangon formosus: Hay and Shore, 191S, p. 384, pi. 26. fig.
5— Schmitt. 1935a, p. 144.

Recognition characters. — Rostrum beginning at
posterior line of eyes and reaching about to second
article of antennular peduncle; flat above; mar-
gins concave at base but regularly convergent
anteriorly and with scattered stiff hairs; tip
rounded, often bearing two or three minute spines.
Carapace half length of abdomen, compressed,
not grooved; orbital hoods each with an acute,
anteriorly directed spine much shorter than ros-
trum; anterior margin emarginate below orbital
hoods. Eyes completely covered by carapace.
Antennular peduncles with scalelike stylocerite,
slender tip reaching slightly beyond basal article;
second article twice length of third; inner flagel-
lum filiform, outer flagellum thick proximally,
filiform distally. Antenna longer than body;

Figure 52. -Alpheus formosus Gibbes. A. anterior pari
■ if bod; in dorsal view ; B, outer surface of large chela :
5 nun. indicated.

antennal scale with strong apical spine reaching
to or beyond tip of antennular peduncle, spine
separated from and exceeding lamella; a weak
spine (basicerite) below near base of scale. Third
maxillipeds with terminal joint hairy; slightly
exceeding antennal peduncle.

First legs strongly chelate, very unequal.
Larger leg compressed, smooth above and un-
notched along margins; immovable finger acute,
incurved at tip, shorter than stout and gradually
arched, blunt dactyl; carpus short, convex above,
with a distal tooth; merus with an acute distal
spine. Smaller chela much more slender, long,
and smooth, inner surface with a stout spine over-
hanging base of dactyl; immovable finger nearly
straight, slender, somewhat turned up near tip;
dactyl about half length of hand, nearly straight
to about middle, then gently arched to tip, hairs
arising from a nearly straight groove below ridge
on both sides; inner surfaces of fingers with a
slender groove and carina ; fingers shutting closely.
Second pair of legs slender; weakly chelate;
carpus subdivided, with joints diminishing in
length as follows (numbered from proximal end) :
1, 5, 2, 3—1. Third to fifth legs with simple
dactyls.

Telson with two pairs of dorsal spines at about
one-third and two-thirds length; posterolateral
corners with a pair of spines, medial spine much
longer than lateral, distal margin with long hairs.
Uropodal exopods with lateral margin ending in
a black movable spine between two fixed spines;
black spine remaining amber colored after long
preservation.

Measurements. — Length of body: ovigerous fe-
males, 17 to 35 mm.

Color. — Color pattern conspicuous and charac-
teristic; ground color yellowish or greenish brown
finely speckled with orange; a narrow light stripe
along middorsal line extending from distal end
of antennular peduncle to base of telson, line
light orange anteriorly merging into yellowish
green and finally gray posteriorly, a brown stripe
on each side dorsolaterally and below this another
stripe of white, or colors similar to dorsal stripe,
along each side followed by a stripe of light red-
dish brown and still another stripe of blue border-
ing abdomen; chelae greenish brown with orange
icd fingers; antennules, antennae, and walking

til

FISH AND WILDLIFE SERVICE

legs blue; telson and uropods white at base
blotched and bordered with yellow.

Habitat. — Lives in holes and crevices in shell
bars, stones, and dead corals; water's edge to
23 fathoms.

Type locality. — Key West, Fla.

Known range. — Near Beaufort, N.C., through
West Indies to Santos, Sao Paulo, Brazil; Ber-
muda.

Remarks. — Ovigerous females have been taken
off Venezuela in April, Beaufort, N.C., in July,
Bimini in October, and Santos, Brazil, in June.
Manter (1934) found metacercariae of Heli-
cometrina nimia encysted in muscles of A. for-
mosus at Tortugas.

Alpheus normanni Kingsley. Green snapping shrimp
Figure 53

Alpheus a/finis Kingsley, 187Sa, p. 195.

Alpheus normanni Kingsley, 1878b, p. 93.

Alpheus packardii Kingsley, 1880, p. 417. — Verrill, 1922, p.
80, pi. 20, figs. 2-5 ; pi. 21, fig. 5 ; pi. 22, fig. 7 ; pi. 23. figs. 6,
c-d ; pi. 25, figs. 4, a, b ; pi. 31, figs. 1, b-1, 2, b-u, 3, u, t (rev.).

Crangon packardii: Hay and Shore, 1918, p. 385. pi. 26, fig.
4. — Sehmitt, 1035a, p. 144.

Recognition characters. — Rostrum with carina
extending as far back as base of eyestalks, spini-
form tip not reaching to base of second article
of antennule. Carapace about two-thirds length of
abdomen, somewhat compressed; cervical groove
hardly evident; front with ocular hoods pro-
duced into an obtuse angle above each eye; an-
terior margin emarginate below ocular hoods.
Eyes well developed but completely covered by
carapace. Stylocerite scalelike with spiniform tip
reaching about to end of basal article of anten-
ule; third article much shorter than second; inner
antennular flagellum slender, outer one shorter
with proximal four-fifths enlarged. Antennae a
little longer than body, slender; antennal scale
reaching a little beyond end of antennular pedun-
cle, lateral margin slightly sinuous with strong
terminal spine separated from and exceeding
lamella; a strong ventral spine (basicerite) near
base of scale. Third maxillipeds slender, not
reaching tip of antennal scale; terminal article
with long hairs.

First legs strongly developed with chelae un-
equal. Larger leg broad and flattened; slightly
sinuate along inner margin; outer margin with a
longitudinal groove above and below, a ridge

Figure 53. — Alpheus normanni Kingsley. A. anterior por-
tion of body in dorsal view; B, large chela in ventro-
lateral view ; 5 mm. indicated.

between grooves ending in a strong tooth behind
base of dactyl ; dactyl heavy, curved, toothed at
base. Smaller chela about half as wide and three-
fourths as long as larger one; similarly formed
but with a sharp spine above (and a small one
below in males) at base of dactyl; no basal tooth
on dactyl; sexually dimorphic ringers in males
broad externally but with keeled, closely fitting
opposed edges fringed by dense hairs; females
with hand a bit hairy but fingers unornamented ;
carpus of both legs short, broad, irregularly cup
shaped, merus with a spiniform tooth near distal
end and one or two spines below, distal end cupped
to receive carpus with leg extended. Second legs
very slender, weakly chelate; with carpus sub-
divided, joints diminishing in length as follows
(numbered from proximal end) : 2, 1, 5, 3-4.
Third to fifth legs with dactyls simple.

Abdomen somewhat compressed. Telson with
sides slightly convergent distally; two pairs of
dorsal spines, first pair at one-third, second at

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

two-thirds length; tip broadly rounded, a pair
of spines at each posterolateral corner, distal mar-
gin heavily setose ; a pair of anal tubercles beneath
with accompanying cups on uropods forming
locking devices. Uropods oval; exopod with
lateral margin ending in a small spine flanked
medially by a strong movable tooth.

Measurements. — Length of body : male, 26 mm. ;
ovigerous female, 16 mm.

Color. — Gray or dull green, sometimes with a
median and lateral stripe of whitish often clouded
or mottled with dark green or brown, a paler spot
behind each eye; large chela dark green usually
banded with yellowish brown or yellow on inner
surface; smaller chela and other legs paler, often
banded with dull gray or reddish; occasionally
body banded with red and pale yellow, large chela
with two pale bands, immovable finger blackish,
dactyl reddish (various authors).

Habitat. — Shelly or rocky bottoms, in burrows
in sand or on pilings in shallow water; common
in saltier portions of estuaries; water's edge to
40 fathoms.

Type locality. — Key West, Fla.

Known range. — North Carolina through West
Indies to Barbados, Curasao, and Aruba ; Alliga-
tor Harbor, Fla., to Sabine, Tex.; Bermuda;
Sonora, Mexico ( ? ) .

Remarks. — This is one of the commonest snap-
ping shrimps in the Beaufort, N.C., region. As
Hay and Shore (1918) pointed out, this was
probably the species called Alpheus minor in
early lists for the area. The latter species is cor-
rectly referred to Synalpheus minus (Say) and
is found only in offshore waters, a different
habitat from that frequented by Alpheus nor-
manni. Brooks and Herrick (1892) followed the
older lists in calling this species Alpheus minor
(minus) and illustrated the adult in color on
plate 1 and larval stages on plates 16 and 17.
They illustrated the first three larval stages, as
well as stages in segmentation of the embryo, but
their specific identifications are somewhat unre-
liable.

Ovigerous females have been taken through
much of the annual cycle in various localities:
January and March, Cuba; June, Louisiana; Au-
gust, Bermuda, Louisiana, Mississippi: April to
September in the Carolinas; November and De-
cember, Puerto Rico.

Alpheus heterochaelis Say. Big-clawed snapping shrimp
Figure 54

Alpheus heterochaelis Say, 1818, p. 243. — Verrill, 1922, p. 76,
pi. 22, figs. 1, 2, 4, a-c; pi. 24, figs. 7, 7a ; pi. 30, figs. 1-la, It
2a-2e ; pi. 33, figs. 1 ,2 (rev.).

Crangon heterochaelis: Hay and Shore, 1918, p. 386, text-fig.
8, pi. 26, fig. 6.— Schmitt, 1935a, p. 144.

Recognition characters. — Rostrum carinate, ex-
tending back about as far as base of eyestalks; tip
not reaching to base of second article of ant en -
nular peduncle. Carapace more than half length
of abdomen, somewhat compressed; without
grooves; front produced into a rounded ocular
hood over each eye; rostro-orbital depressions
passing gradually into dorsal surface; emargi-
nate below eye on anterior border. Eyes relatively
small, covered by carapace. Antennular peduncles
with scalelike stylocerite, minute spine at tip not
reaching end of basal article; second article twice
length of third; inner flagellum filiform, about
half length of antenna; outer flagellum with
proximal two-thirds thickened. Antennae a little
longer than body; antennal scale with strong
apical spine reaching slightly beyond antennular

Figure 54. — Alpheus heterochaelis Say. A, anterior por-
tion of body in dorsal view, 5 nun. indicated; B, large
chela in dorsal view, 5 mm. indicated ; C, small chela
of male (after Verrill. 1922).

FISH AND WILDLIFE SERVICE

peduncle, spine separated from and slightly ex-
ceeding lamella; a weak spine (basicerite) below
near base of scale. Third maxillipeds with ter-
minal article hairy; slightly exceeding antennal
peduncle.

First legs strongly chelate, very unequal. Larger
chela thick; outer and inner margins deeply
notched near base of fingers; upper and lower
surfaces with irregular shallow grooves; dactyl
broad, heavy, strongly curved, with large basal
tooth. Small chela sexually dimorphic; in male
broad, elongate; proximal dorsal area of palm
bounded by an impressed line, upper margin
notched distally; dactyl flattened and expanded
on outer surface; opposed edges of fingers keeled,
closely fitting, fringed by dense hairs. Fingers
of small chela in both sexes weaker, less curved,
and more hairy than in large chela ; carpus short ;
merus smooth. Second legs slender, weakly che-
late; carpus subdivided with joints diminishing
in length as follows (numbered from proximal
end) : 1, 2, 5, 4, 3. Third to fifth legs with simple
dactyls.

Abdomen compressed, smooth, tapering. Telson
with subparallel sides and rounded tip; dorsal
surface with two pairs of movable spines, first
pair at about midlength, second at a little less
than three-fourths length; a pair of spines at
each posterolateral corner, medial spine longest;
distal margin heavily setose, a pair of anal tuber-
cles beneath with accompanying cups on uropods
forming locking devices. Uropodal exopods with
lateral border ending in a fixed spine flanked
medially by a longer movable spine.

Measurements. — Length of body : male, 40 mm. ;
female, 50 mm.

Color. — Dark translucent green, slightly flushed
with purple on sides of carapace ; white markings
on chelipeds; walking legs pale red; tips of
uropods blue with narrow border of orange on
distal margin, outer blade with patch of red just
above blue, and a narrow white border; articular
surfaces and joints of abdominal segments, and a
small streak along cervical groove, white.

Habitat. — Lives among broken shells and stones
or in burrows in mud among shells; water's edge
to 16. fathoms.

Type locality. — Amelia Island, Nassau County,
Fla. (Holthuis, 1959, restr.).

Known range. — Near Hatteras, N.C., to Aransas
County, Tex.; Colon, Panama; through West
Indies to Iguape, Sao Paulo, Brazil; Bermuda
(Holthuis, 1956).

Remarks. — Brooks and Herrick (1892) gave a
good colored figure of this species (plate 2), as
well as a series of figures of segmenting eggs and
developing larval stages. Because the material
they studied originated from both North Carolina
and the Bahamas, there is some doubt as to its
identity, but a total of four larval stages were
illustrated.

This is the largest snapping shrimp found in
the Carolinas. It is nearly as abundant as A.
normanni.

Ovigerous females have been taken through
much of the annual cycle in various localities:
February and April in Surinam (Holthuis, 1959) ;
March in Panama and Texas; April and May in
Louisiana and Florida; July in North Carolina;
August and September on the Gulf Coast; Octo-
ber to January in Cuba, Puerto Rico, and
Bonaire.

Alpheus armillatus Milne Edwards. Banded snapping
shrimp

Figure 55

Alpheus armillatus H. Milne Edwards, 1837, p. 364. — Verrill,
1922, p. 73, text-figs. 5a, 6b ; pi. 20, fig. 4b ; pi. 21, figs. 4, 4a ;
pi. 26, figs. 1-ld; pi. 23, fig. 4; pi. 27, figs. 1-ls (rev.).

Crangon armillatua: Hay and Shore, 1918, p. 386, text-fig. 9;
pi. 27, fig. 1. Schmitt 1935a, p. 142.

Recognition characters. — Rostrum in form of a
narrow raised crest from base to tip, projecting
beyond orbital hoods, widening abruptly just be-
hind eyes into a triangular area with borders
slightly concave and distinctly limiting rostro-
orbital depressions, slightly overhanging depres-
sions in adult specimens. Carapace compressed;
orbital hoods prominent in front with a slight
obtuse anterior lobe, but without spine or denticle,
and with a strong emargination below eyes. Eyes
entirely covered by carapace. Antennules with
stylocerite large, scalelike, not very acute, and not
reaching to end of basal antennular article ; second
article longer than third ; inner flagellum filiform ;
outer flagellum thickened in about proximal half.
Antennal scale with a strong terminal spine equal
to or extending beyond antennal peduncle, scale
distinctly curved outward in distal two-thirds;
a small spine ( basicerite ) near base of scale. Third

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Figuse 55. — Alpheus armiUatus Milne Edwards. A, an-
terior portion of body in dorsal view ; B, rostral region
in dorsal view with light showing from posterior ; C.
large chela in dorsal view ; A-C, 5 mm. indicated.

maxilliped covered with long hairs distally, reach-
ing about to end of antennal peduncle.
* First legs strongly chelate, hairy, unequal.
Larger chela thick ; outer and inner margin deeply
notched near base of fingers; upper and lower
surfaces with irregular shallow grooves; dactyl
broad, heavy, curved, with large basal tooth.
Small chela slender; cutting edges of fingers
closely fitting, dactyl with a small tooth at base,
dactyl in males lacking setose crests and expanded
external surface characteristic of A. heterochaelis.
Second legs long, slender, weakly chelate, with
part of merus reaching beyond rostrum; carpus
subdivided with joints diminishing in length as
follows (numbered from proximal end) : 1, 2, 5,
3-4. Third to fifth legs with simple dactyls.

Abdomen smooth, compressed. Telson with two
pairs of dorsal spines, iirst pair al one-third,
second al two-thirds Length; sides somewhat

convergent distally, tip rounded, with a pair of
spines at each posterolateral corner, medial spine
twice length of outer spine. Uropodal exopod
with outer margin ending in a small spine flanked
medially by a larger spine.

Measurements. — Length of body: ovigerous fe-
males, 31 to 38 mm.

Color. — Body with dark gray or brown ground
color, crossed by nine conspicuous lunate or
elliptical spots or bands of translucent white equal
in width to intervening dark bands; carapace with
three white bands, third one at posterior margin;
abdomen with six bands, first blending with last
on carapace; abdominal bands usually whiter or
more clearly defined than bands on carapace;
abdomen often dark green with spots bordered by
line of orange; uropods and telson usually with
a broad crossband and sometimes tipped with
orange; chelae thickly speckled with dark gray,
whitish bands above, tipped with pale pink or
white; antennal peduncles grayish, flagella and
walking legs orange yellow banded with white
(Verrill, 1922).

Habitat. — Under rocks and shells or in holes
in rocks; shallow water.

Type locality. — "West Indies.

Known range. — North Carolina, through West
Indies to Cananeia, Sao Paulo, Brazil; Bermuda
(Holthuis, 1956).

Remarks. — This species closely resembles A.
heterochaelis, its similar sized and (in the Caro-
linas) much more abundant congener. Alpheus
armiUatus is named for its conspicuously banded
body, but in preserved material it can be dis-
tinguished from similar species by the distinctive
form of the rostrum and from ^4. heterochmlis
males by the lack of the specialized dactyl on the
small first chela.

The species is rarely taken in the Beaufort
region of North Carolina. Hay and Shore ( 1918 )
found males and females living in pairs under
rocks at Fort Macon. Ovigerous females are
known from only the first half of the annual
cycle: March, Panama : April, Venezuela: May,
Barbados; June, Florida and Brazil: August,
Bermuda.

Pearse (1932b) reported encysted larvae of
Rhyncobothrius in viscera of .1. armiZlatus.

Coonfield (1910) observed the chromatophore
system of this shrimp in one of the early studies

FISH AND WILDLIFE SERVICE

of this kind, showing that it reacts to different
backgrounds under varying light conditions.

Hess (1940, 1941) demonstrated that A. arrnilla-
tux is sensitive to light in many regions of the
body, regardless of the amount of time elapsed
since the preceding molt. At Tortugas, he found
that diurnal molting in this shrimp is apparently
controlled by daily temperature changes, molting
occurring when the temperature rises to or above
29° C. Animals in constant temperature failed to
exhibit diurnal molting as did ovigerous females.

Darby (1934) studied regeneration of chelae
in A. armillatus and Synalpheus longicarpus to-
gether with determination of right or left handed-
ness. He found that in development of chelae a
stage was reached that permitted determination
of which side would have a large chela. Equal
chelae were produced experimentally and were
of three varieties: (1) both small (pinch claws) ;
(2) both large (snap claws) ; and (3) both
intermediate.

Darby offered an hypothesis, involving two
substances and a metabolic condition, which could
explain the regenerative phenomena in these and
allied crustaceans. In such animals, a substance A
is produced which controls production of pinch
claws ; but at certain stages in the intermolt cycle
a substance B is produced, for a limited time, and
is concentrated in whichever claw is regenerating
or already modified as a snap claw. This circum-
stance will produce or reinforce production of a
snap claw. Chance alone is responsible for whether
a snap claw will be on one side or the other, or
whether the animal will be symmetrical. Also,
time at which regeneration occurs depends on
chance.

Genus Synalpheus Bate, 1888

Banner, 1953, p. 26.— Hemming, 195Sb, p. 161.

KEY TO SPECIES IN THE CAROLINAS

a. Dactyls of third, fourth, and fifth legs with two very
unequal hooks, ventral strongest (broadest) ; an incon-
spicuous, obtuse supernumerary process proximal to

ventral hook fritzmuelleri subsp. (p. 69).

aa. Dactyls of third to fifth legs with two hooks approxi-
mately equal in width at base.

b. Dactyls long and slender, hooks continuing general
direction of axis of dactyl : stylocerite longer than
basal article of antennular peduncle : lamella of an-
tennal scale present.

c. Frontal teelth more or less equilaterally tri-
angular, at times with concave margins, but
never with an inferior vertical prolongation to
rostrum ; basicerite strongly spinous above

minus ( p. 70).

cc. Frontal teeth always longer than wide, spinous ;

rostrum armed with a ventral prolongation which

embraces ocellary beak ; basicerite unarmed

above townsendi (p. 72).

bb. Dactyls short, hooks strongly curved, ventral one
usually bent at considerable angle to axis of dactyl ;
stylocerite not exceeding first article of antennular
peduncle ; antennal scale lacking lamella in male,
small in female longicarpus (p. 73).

Synalpheus fritzmuelleri Coutiere

Figure 56

Synalpheus fritzmuelleri Coutiere, 1909, p. 35, fig. 18. — Ver-
rill, 1922, p. 97. Schmitt, 1935a, p. 14S.

Recognition characters. — Rostrum slender,
compressed, acute from dorsal view, a little longer
than orbital spines, reaching to midlength of
visible portion of basal antennular article. Orbital
spines wide at base, acuminate; margins incurved.
Eyes completely covered by carapace. Antennular
peduncle with stylocerite of basal article reaching

Figure 56. — A, Synalpheus fritznwelleri Coutiere, anterior
portion of animal in dorsal view ; B, Synalpheus fritz-
muelleri elongatus Coutiere, anterior portion of animal
in dorsal view ; 1 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 O — 65 6

to middle of second article; third article slightly
shorter than second; inner flagellum filiform
outer bifurcate beyond about eighth joint, thick-
ened proximally. Spine of antennal scale equaling
terminal article of antennal peduncle, both reach-
ing a little beyond antennular peduncle, spine
separated from and exceeding narrow lamella
distally; basicerite with a short, sharp lateral
spine nearly as long as stylocerite; above it a
smaller, acute, secondary spine.

First pair of legs chelate, unequal. Large chela
ellipsoidal, only a little swollen in middle ; a small
obtuse tubercle on distal dorsal margin ; width of
palm about one-third total length of chela; dactyl
heavy, strongly arched above; immovable finger
narrow at tip; carpus short and wide, prolonged
downward and inward; merus stout, superior
margin ending distally in a sharp angular point.
Smaller chela similar in form; fingers pointed;
carpus short, cup shaped; merus like that of
larger chela. Second legs slender, weakly chelate ;
carpus subdivided, first joint about equal to re-
maining four. Third to fifth legs with bifurcate
dactyls, hooks unequal; outer one thinner and a
little longer, regularly curved, sharp; inner one
wider at base, strongly divergent, curved inward ;
proximal to inner hook a slight obtuse protuber-
ance or rudimentary spur.

Telson broad, tapering, obtusely rounded dis-
tally ; each posterior angle with a pair of unequal
spines; two pairs of small dorsal spines, first pair
at midlength, second at three-fourths length.
Uropodal exopods with lateral margin ending in
a~ notch with a fixed spine on each side, a longer
movable spine between them.

Measurements. — Length of body: ovigerous fe-
male, 22 mm.

Variations. — In the subspecies S. f. elongatus
Coutiere (1909, p. 37, fig. 19) the lateral spine
of the antennal scale greatly exceeds the terminal
article of the antennal peduncle, and the rostrum
is decidedly longer than the ocular spines. In
the subspecies S. f. carolinensis Verrill (1922, p.
99, pi. 22, fig. 6; pi. 39, figs. 1-ld) and S. f.
caribaea Verrill (1922, p. 98, text-fig. 8; pi. 39,
figs. 3a-3c) the basicerite is shorter than in typical
specimens.

Color. — Synalpheus fritzmuelleri: chela vary-
ing shades of green, darker toward extremities of
fingers; body more or less colorless, specked with

quite numerous tiny red chromatophores. Syn-
alpheus fritzmuelleri elongatus: similar to pre-
ceding; chelipeds and second legs blue, except
anterior part of chela light green (Schmitt, 1930) .

Habitat. — Often found living in sponges; low
tide mark to 28 fathoms.

Type locality. — Synalpheus fritzmuelleri, Mar-
co, Fla. ; S. f. elongatus, Mouth of Bull Creek, S.C.

Known range. — Typical fritzmuelleri: Nege,
Greenland (Stephensen, 1950) ; off Beaufort, N.C.,
to Port Aransas, Tex.; West Indies to Curasao;
Old Providence Island ; Tres Marias Archipelago,
Mexico; Bermuda. Subspecies elongatus: off
Beaufort, N.C., to Florianopolis, Santa Catarina,
Brazil, including Jamaica and Barbados; Tres
Marias Archipelago, Mexico. Subspecies caro-
linensis: Fort Macon, N.C. Subspecies caribaea:
Dominica.

Remarks. — Distribution of the named sub-
species and varieties of Synalpheus fritzmuelleri
shows that modern revisionary work in the West-
ern Atlantic is needed. Until thorough study is
made, the various names must be retained, but
it is likely that the present designations do not
adequately explain local populations which par-
allel each other at widely separated locations.
As Banner (1953) pointed out, earlier workers,
with only a few specimens from these widely
separated localities, naturally tended to name the
variants, the range of variation being then un-
known. Varietal names, therefore, must be re-
garded as conditional. Verrill (1922, p. 89) may
have concurred for he quoted Stebbing's dim
view of naming infinite variations but proceeded
to name varieties anyway.

In the Carolinas, this species lives on offshore
reefs (Pearse and Williams, 1951) in large
sponges. Specimens may be found in beach drift,
after severe storms. Ovigerous females of typical
fritzmuelleri are known from the Carolinas in
February, and June to October, indicating a long
breeding season. Ovigerous females of S. f.
elongatus are known from Barbados in May, and
North Carolina in June and July.

Synalpheus minus (Say)

Figure 57

Alpheu8 minus Say, 1818. p. 245.

Synalpheus minus: Hay and Shore, 1918, p. 382, text-fig. 5 ;
pi. 20. fig. 3 (rev.).— Verrill, 1922, p. 102, pi. 21, fig. 1; pi. 23,
fig. 3 ; pi. 25, fig. 3 ; pi. 31, fig. 4 ; pi. 33, figs. 4. 4a ; pi. 36, figs.
1-ld, 2; pi. 47, figs. 1-lc, 2; pi. 48, figs. 3-3c (rev.). — Schmitt,
l!»35a. p. 149.

FISH AND WILDLIFE SERVICE

Recognition characters. — Front of carapace
with three teeth each in form of equilateral tri-
angle; rostrum usually a little wider at base,
compressed and sometimes slightly longer than
orbital teeth. Eyes completely covered by large
orbital hoods. Basal article of antennular pe-
duncle with stylocerite reaching to distal third
of second article; third article half length of
second; second of intermediate length; inner
flagellum filiform, outer flagellum thickened
proximally. Antennal scale narrow, inner edge
regularly curved; lateral spine a little longer than
antennular peduncle, separated from and exceed-

Figure 57. — Synalpheus minus (Say). A, anterior part
of body in dorsal view, with appendages of right side;
B, large chela ; C, small first cheliped ; D, second leg
showing subdivided carpus ; E, dactyl of third leg ; F,
telson in dorsal view (after Coutiere, 1909).

ing lamella; basicerite reaching to distal end of
basal antennular article, above it a prominent
secondary spine.

First legs chelate, unequal, thicker in male
than in female. Large chela ovoid; palm about
2.5 times length of fingers, anterior dorsal margin
with a strong, sharp tooth at inner side and a
blunter tooth on lateral and ventral side near
base of dactyl ; dactyl broad, larger than immov-
able finger, tip obtuse, cutting edge a little
sinuous, a large tooth at base, dorsal edge curved
distally; immovable finger with tip nearly
straight, inner edge a little sinuous. Smaller chela
elongate, slender, about one-third length of larger;
fingers a little shorter than palm, with tufts of
hair, acute at tips and curved a little downward ;
palm narrowly elliptical, surface plain. Second
legs slender, weakly chelate; carpus subdivided
with joints diminishing as follows (numbered
from proximal end) : 1, 5, 2-3^1.

Telson with sides slightly sinuous, tip broadly
rounded ; two pairs of dorsal spines, first pair at
about midlength, second pair at about three-
fourths length; distal margin with a pair of
spines at each posterolateral corner. Uropodal
exopods with lateral margin ending in notch
armed with two spines separated by a longer
movable spine.

Measurements. — Length of body: female, 35
mm.

Color. — Body translucent, yellowish white;
large chela white or translucent gray, fingers
orange, tips red ; banded near base of fingers with
white in female, white tipped with green in male.

Habitat. — Lives in dead corals and commensally
in sponges; shallow water to 37 fathoms.

Type locality. — Southern [United] States.

Known range. — Near Cape Hatteras, ' N.C.,
through West Indies to Alagoas, Brazil ; Bermuda.

Remarks. — A number of authors, among them
Hay and Shore (1918) and Verrill (1922), have
pointed out that Brooks and Herrick (1892) er-
roneously called Alphews norrrwrwd (=pacJoardii)
by the name A. minus in their profusely illus-
trated monograph. The true Synalpheus minus
was not treated by them, however, and, at least in
the Beaufort, N.C., area, was not available to them
in the harbor area studied.

A long breeding season is indicated for this
species. Ovigerous females have been taken from

MARINE DECAPOD CRUSTACEANS OF THE CAROLTNAS

February to November in various localities from
North Carolina to the Gulf coast; in April in
Bermuda; and September in Venezuela. Adults
usually occur in pairs (Wass, 1955).

Synalpheus townsendi Coutiere. Small snapping shrimp

Figure 58

Synalpheus townsendi Coutiere, 1909, p. 32, figs. 14-17 ; Hay
and Shore. 1918, p. 384, pi. 26. fig. 1 (rev.). — Verill, 1922, p.
100 (rev.).

Recognition characters. — Rostrum slender, 1.5
times as long as lateral teeth and reaching usually
to end of proximal third of second article of
antennular peduncle, armed with a ventral pro-
longation embracing ocellary beak. Teeth on
orbital hoods slender; eyes completely covered by
hoods. Basal antennular article with stylocerite
reaching about as far as rostrum; third article
about half length of second ; inner flagellum fili-
form, outer flagellum thickened proximally,
bifurcate beyond fourth joint. Antennal scale
with strong, slender lateral spine separated from
and exceeding lamella distally, spine reaching
about to or beyond end of antennal peduncle;
basicerite well developed, angled above but lack-
ing dorsal spine, extremity reaching to distal third
of basal antennular article.

First pair of legs chelate, very unequal. Large
chela with a small, acute dorsal spine at distal
margin of palm ; upper margin of dactyl elevated
into a thick crest; carpus small, irregularly short-
ened; merus with dorsolateral margin convex,
ending in a hooked spine. Small chela one-third
length of large one; no brush of hairs on dactyl.
Second pair of legs slender, weakly chelate;
carpus subdivided, first joint longer than others
combined. Third to fifth legs with bifurcate
dactyls, both hooks nearly parallel, ventral one
narrower and much shorter than dorsal.

Abdomen compressed. Telson with sides some-
what convergent; posterior angles sharp and each
provided with a pair of spines, inner spine longer
than outer; two pairs of strong dorsal spines, firsl
pair at one-third, second at two-thirds length.
Uropods ovate, exopod with lateral margin ending
in a notch with a strong fixed spine at its outer
and inner angles, between these spines a longer
movable spine.

Measurements. -Length of body: ovigerous fe-
males, 13 mm.

Figure 58. — Synalpheus townsendi Coutiere. A, anterior
part of body in dorsal view, with appendages of left
side; B, tip of large chela; C, large, cheliped, merus.
carpus and proximal end of propodus; D, small first
cheliped; E, second leg showing subdivided carpus; F,
dactyl of third leg; (J, telson in dorsal view (after
Coutiere, 100!)).

Variations. — The rostrum is variable in length,
often shorter than as described above.

Color. — Body and legs translucent pinkish red;
large chela pink, changing to green on lingers.

Habitat. — Often found in large sponges; low
! ide mark to 56 fathoms.

Type locality. — Gulf of Mexico, Albatross sta-
tion 2373.

FISH AND WILDLIFE SERVICE

Known range— -Off Beaufort, N.C., to Yucatan;
through West Indies to Bahia, Brazil ; Bermuda.

Remarks. — This species has been taken from
offshore reefs in North Carolina at depths of 7
to 8 fathoms (Pearse and Williams, 1951), and
from sponges at depths of 16 to 20 fathoms. Wass
(1955) remarked that the species seems less de-
pendent on sponges than other members of the
genus taken in the Alligator Harbor area of
Florida.

Ovigerous females have been taken from the
Carolinas in February and August; Obregon,
Mexico, in July and August; and Venezuela in
September.

Synalpheus longicarpus (Herrick)
Figure 59

Alpheua saulcyi var. longicarpus Herrick [in part], 1892, p.
383.

Synalpheus longicarpus: Hay and Shore, 1918, p. 383. text-fig.
6 ; pi. 26, fig. 2 (rev.). — Verrill, 1922, p. 113, pi. 25, figs, la-lh ;
pi. 34, figs. 3, 3c ; pi. 36, figs. 5, 5a (rev.).

Recognition characters. — Rostrum carinate,
slender, and slightly longer than triangular, ob-
tuse orbital hoods, reaching about to middle of
basal antennular article; space between rostrum
and hoods U-shaped, broadest in females. Eyes
small, completely covered. Basal article of an-
tennular peduncle with short stylocerite reaching
to distal third of article; second article one-third
longer than third article; inner flagellum filiform,
outer branching at seventh joint, thickened prox-
imally. Terminal article of antennal peduncle
exceeding antennular peduncle; antennal scale
with strong terminal spine separated from and
exceeding rudimentary lamella distally; spine
variable in length, often exceeding antennular
peduncle by half length of distal article; lamella
of scale rudimentary in males, small and variable
in females ; basicerite slender, acute, with an angle
but no accessory spine above, tip reaching to end
of second article of antennular peduncle.

First legs chelate, very unequal. Large chela
elongate, somewhat ovate, about 2.75 times longer
than broad; margins somewhat convex; posterior
end swelled and produced backward beyond ar-
ticulation with small, short carpus inserted below
central axis of palm; anterior dorsal margin of
palm with small, acute spine near base of dactyl;
dactyl somewhat oblique at end, toothed at base,

about one-fourth to one-fifth length of chela.
Small chela elongate, about one-third length of
larger; dactyl elongate, gently arched dorsally, a
dense tuft of erect hairs on dorsal surface along
most of length, cutting edge nearly straight with
two apical teeth; immovable finger with three
teeth, apical one stronger. Second pair of legs
slender, weakly chelate; stronger in male than in
female; carpus subdivided, first joint shorter than

Figure 59. — Synalpheus longicarpus (Herrick). Anterior
part of body in dorsal view, A, male, B, female ; C, large
chela ; D, small first cheliped, male ; E, same, female ;
F, fingers of small first cheliped ; G, second leg of male
showing subdivided carpus ; H, same, female ; I, dactyl
of third leg; J, same in large adult; K, telson and left
uropods in dorsal view, female; L, tip of telson (after
Coutiere, 1909).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

sum of remaining four. Third to fifth legs with
dactyls bifurcate.

Sixth abdominal segment with a strong tri-
angular tooth on each posterior angle. Telson with
sinuous sides tapering to subtruncate tip; dorsal
spines strong, first pair at one-third, second at
two-thirds length; tip with two pairs of strong
spines, inner pair slightly longer. Uropodal
exopod broadly oval; lateral border spined with
seven or eight denticles, a movable spine at distal
end of series.

Measurements. — Length of body : ovigerous fe-
males, 16 to 22 mm.

Variations. — Length of the carpus of the small
claw varies with age. The rostrum and projections
on the orbital hoods may be entirely lacking or
their relative lengths may vary (Wass, 1955).

Color. — Translucent white; ringers brown.

Habitat. — Lives at depths of 15 to 28 fathoms
in interior of sponges; especially abundant in
Spheciospongia {= Spirastrella) (Wells, Wells,
and Gray, 1960) . Sometimes found in sponges cast
on beach during storms at Beaufort, N.C.

Type locality. — Specimens upon which Her-
rick's description is based were taken in the
Bahamas, probably at Nassau, New Providence
Island.

Known range. — Beaufort, N.C, to Yucatan,
Mexico; through West Indies to Curasao.

Remarks. — This species is common in the Caro-
linas and often occurs in enormous numbers in the
canals of large sponges. Infestation by parasitic
is.opods is common, Phryxus subcaudalis Hay oc-
curring on the surface of the abdomen and Syn-
synella deformans Hay in the branchial chambers.

Ovigerous females have been taken off North
Carolina in August and December. The species
hatches in essentially the adult form (Herrick,
1892). Coutiere (1909) and Wass (1955) re-
marked on the fact that few ovigerous females
occur among crowded populations in sponges.

Family Ogyrididae

Caridea with first two pairs of legs chelate,
nearly equal in size and not much if any larger
than other legs. Carpus of second legs subdivided.
Rostrum small or wanting. Eyestalks long,
slender, fully exposed but with corneal surface
reduced. Telson thick, obtusely pointed. Blades

of uropods curved outward. Thelycum present
in females (Hay and Shore, 1918).

Genus Ogyrides Stebbing, 1914

Stebbing, 1914, p. 31 ; Hemming, 1958b, p. 158.

KEY TO SPECIES IN THE CAROLINAS

a. Postrostral crest with 8 to 14 small, fixed spines

limicola (p. 74).

aa. A single movable spine behind rostrum on middorsal

line alphaerostris (p. 75).

Ogyrides limicola Williams

Figure 60
Ogyrides limicola Williams, 1955c, p. 57, fig. 1.

Recognition characters. — Rostrum short, de-
pressed, equilaterally triangular. Postrostral
carina with 8 to 14 teeth, flanked on each side by
row of setae extending to tip of rostrum.
Pterygostomian area broadly obtuse. Eyestalks
long, lightly setiferous dorsally and dorso-
medially, narrowest in middle, exceeding anten-
nular peduncles by approximately 2.5 times
corneal length. Antennal and antennular pedun-
cles nearly equal in length; second antennular
article 3 times as long as third article ; stylocerite
of basal article terminating in two strong acumi-
nate spines of nearly equal length. Antennal scale
and second article of antennular peduncle reach-
ing nearly same level distally; scale evenly

Figube 60. — Ogyrides Umicola Williams. A, carapace and
anterior appendages in lateral view ; B, anterior ap-
|)endages and i>orti<>n of carapace in dorsal view; C.
telson and uroj>ods of right side in dorsal view ; A-C
approximately X 10 (after Williams, 1955c).

FISH AND WILDLIFE SERVICE

rounded medially, 3 times longer than greatest
width, greatest width in basal half. Third
maxilliped, when extended, exceeding eyestalks.

First legs exceeding midlength of antennal
peduncle by full length of chelae; fingers of chelae
pointed, agape when closed.

Telson with anterior pair of spines placed
well behind lateral prominences. Uropods with
exopods slightly falciform, lateral borders nearly
straight. Telson with three horny ridges at
proximolateral corners ventrally, and uropods
with an interlocking horny eminence on basal
article dorsally.

Measurements.- — Length of body: ovigerous
holotypic female, 16 mm.

Variations. — Individual variations are shown
in the number of spines on the postrostral crest
and in the lengths of the spines of the stylocerite.

Color. — Female with general body structure
colorless, clear; internal organs visible; gut dark;
hepatopancreas light brown; eyestalks, antennal
and antennular peduncles, and distal portions of
anterior appendages with red and yellow spots;
uropods and sixth segment of abdomen with scat-
tered red spots. Ovigerous females with yellow
green (chartreuse) colored eggs on swimmerets
(Williams, 1955c).

Habitat. — On (or in) the bottom of muddy
estuaries, or in plankton; surface to 2.5 fathoms.
Collections have been made in an observed bot-
tom salinity range of 9 to 31°/00., but salinities
in sounds near inlets often range higher than this.

Type locality. — Mouth of Far Creek at Engel-
hard, Hyde County, N.C.

Known range. — Eastern shore of Accomac
County, and lower James Kiver, Va., to Lake
Pontchartrain, La.

Remarks. — The systematic confusion surround-
ing the two species 0. alphaerostris and 0. limicola
was discussed by Williams (1955c). The two
species are quite distinct morphologically and
differ in total size, 0. limicola being the smaller.
The latter occurs most frequently in collections
from estuaries. Young specimens have frequently
been taken in plankton tows made at night in
Bogue Sound, N.C, but adults are seldom taken
by this method of collection. Occurrence of adults
in samples taken with a beam trawl suggests
burrowing habits similar to those described for
0. alphaerostris, but in muddier situations and

often in low salinities. The type locality and a
number of other productive collecting spots in
North Carolina are shallow, mud-bottomed, non-
tidal estuarine streams.

In North Carolina, collections of 0. limicola
have been made in all seasons of the year, and
ovigerous females have been taken from May to
September.

Ogyrides alphaerostris (Kingsley)

Figure 61

Ogyris alphaerostris Kingsley, 1880, p. 420, pi. 14, fig. 7.
Ogyrides alphaerostris: Stebbing, 1914, p. 31. — Hay and Shore,
1918, p. 388, fig. 11, pi. 26, fig. 9.

Recognition characters. — Rostrum depressed,
equilaterally triangular, tipped with setae. A
single, postrostral, movable spine. Pterygostomian
area obtuse. Eyestalks long, setiferous medially,
narrowest in middle, exceeding antennular pedun-
cle by approximately twice corneal length. An-
tennal and antennular peduncle nearly equal in
length; second article of antennular peduncle
slightly over twice as long as third article;

Figure 61. — Ogyrides alphaeroBtris (Kingsley). A
carapace in lateral view ; B, carapace and anterior
appendages in dorsal view ; C, uropods and telson
in dorsal view ; D, sterna of last three thoracic
segments showing thelycum of female : A-C fe-
male X 5, D X 7.8 (after Hay and Shore. 1918).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

stylocerite terminating in two acuminate spines;
lateral spine longer. Antennal scale and second
article of antennular peduncle reaching same level
distally; scale evenly rounded medially, approxi-
mately three times longer than greatest width,
greatest width near base. Third maxilliped, when
extended, exceeding eyestalks.

First legs scarcely extending to tip of antennal
scale. Second legs exceeding antennal scale by
full length of chelae; fingers of chelae pointed,
agape when closed.

Telson with anterior pair of spines placed ap-
proximately at level of lateral prominences.
Uropods with exopods somewhat falciform,
curvature greatest distally. Telson with three
horny ridges at proximolateral corners ventrally,
and uropods with an interlocking horny eminence
on basal article dorsally.

Measurements. — Length of body: ovigerous fe-
male, 27 mm.

Color. — Body nearly transparent ; red and green
spots or flecks on eyestalks, antennules, and an-
tennae; green only on distal joints of third
maxillipeds; red only on basal articles of legs,
on first pleopods, at bases of all pleopods, and on
abdominal pleura and sterna; a conspicuous red
area on sixth abdominal segment distoventrally
and another around mouth.

Habitat. — Often found on firm bars of sand
just offshore along open ocean in water 1 m. deep
(Pearse, Humm, and Wharton, 1942) ; surface to
5 fathoms.

Type locality. — Eastern shore of Northampton
County, Va.

Known range. — Northampton County, Va., to
St. Simons Island, Ga. ; Alligator Harbor, Fla.,
to Horn Island, Miss.

Remarks. — Ogyrides alphaerostris apparently
is more restricted to high-salinity waters than
O. limicola, for it has seldom been collected in
the sounds of North Carolina and then only near
inlets. Pearse, Humm, and Wharton (1942) de-
scribed burrowing habits of the species on sandy
bars and commented that members of the genus
are unusual in that they have long eyestalks like
Uca, yet are burrowers. Ogyrides alphaerostris
burrows forward (head first), using the third
maxillipeds and legs for digging and propulsion.
Sand is pushed upward and over the head, the
abdomen often being left ahove sand for a time,

especially in ovigerous females. The fifth leg is
held high on the sides and stroked dorsally and
posteriorly, legs one to four are stroked laterally
and posteriorly, and the third maxillipeds moved
anteriorly and dorsally. The animals scrape food
from the antennae with setose mouth parts.

Ovigerous females have been taken in July in
North Carolina, and in July and August in Florida
and Mississippi. The above authors imply that the
breeding season is extended through the summer
months.

Family Hippolytidae

Caridea with first two pairs of legs chelate,
first pair not much stronger than rest; carpus of
second pair of legs subdivided. Eyes well de-
veloped and not covered by carapace. Mandibles
usually deeply cleft. Second maxillipeds with a
very short dactyl.

KEY TO GENERA AND SOME SPECIES IN THE
CAROLINAS

a. Carpus of second legs with three to five joints,
b. Carpus of second legs with five joints

Thor floridanus (p.76).
bb. Carpus of second legs with three joints.

e. Series of small spines (five to nine) along an-
terior margin of carapace below eye

Lat rentes (p. 78).
cc. Without series of small spines on anterior margin
below eye.
(1. Rostrum shorter than carapace proper, with

spines above and below Hippolyte (p. 80).

dd. Rostrum nearly twice length of carapace proper,
smooth above, serrate below

Tozcuma cnrolinennc (p. 83).

aa. Carpus of second legs with more than six joints

(multiarticulate) Hippolysmata (p. 84).

Genus Thor Kingsley, 1878

Kingsley, 1878b, p. 94.^Hemming, 1958b. p. 161.

Thor floridanus Kingsley

Figure 62

Thor floridanus Kingsley. 1878b, p. 95.— Verrill. 1922. p. 136,
pi. 35, figs. 2-2f ; pi. 41, fig. 1 ; pi. 46, figs. 2-2e ; pi. 47, figs. 4.
4a.— Holthuis, 1947, p. 47, 49 (rev.).

Recognition characters. — Rostrum shorter than
eyes; dorsal margin with four or five teeth, first
tooth a little behind margin of orbit, distal tooth
near tip making tip appear bifid; ventral margin
unarmed. Carapace smooth, with prominent an-
tennal spine below orbit. Eyes well developed.
Antennules with basal article large; stylocerite
long, acute, reaching beyond tip of basal article

FISH AND WILDLIFE SERVICE

Figure 62. — Thor floridanus Kingsley. A, carapace and
anterior appendages in lateral view, 1 mm. indicated ;
B, antennule ; C. antennal scale; D, uropods and telson ;
B-D, 1 mm. indicated.

to level of tip of spine on second article; a tiny,
erect spinule at base of stylocerite; second and
third articles short; second with slender, acute
spine on lateral surface; third with a thin, flat,
blunt projection on upper side; inner flagellum
slender, slightly longer than peduncle; outer
flagellum stout basally, tapering abruptly to thin
terminal portion, densely hairy on outer margin,
about as long as peduncle. Antennal scale with
outer margin nearly straight, terminating in a
stout spine, lamella exceeding spine, an outer
spine near base of scale. Third maxilliped reach-
ing a little beyond tip of antennal scale; last
article terminating in slender spines.

First legs with merus and carpus subequal;
carpus with minute spinules on inner margin;
chelae subcylindrical, dactyl two-fifths total
length of hand. Second legs with carpus sub-
divided into six joints of varying lengths; chela
as long as fifth and sixth carpal joints. Dactyls
and propodi of third to fifth legs spinulose be-
neath ; dactyls bifurcate but with accessory spines
proximally.

Abdomen smooth; pleura of fourth, fifth, and
sixth segments with posterolateral angles acute.
Telson elongate, triangular, with five prominent
pairs of dorsal spines a little remote from edges
and spaced equidistantly in posterior three-
fourths of length; tip somewhat rounded and
armed with three pairs of subequal spines, outer
pair shortest. Uropodal exopods with outer edge
ending in a small spine flanked medially by a
strong movable spine.

Measurements. — Length of body : ovigerous fe-
males, 11 to 13 mm. (Wass, 1955).

Habitat. — Among sponges, ascidians, algae, and
soft corals ; shallow water to 32 fathoms.

Type locality. — Key West, Fla.

Known range. — Beaufort, N.C., to Alabama;
through West Indies to Curasao and Yucatan;
Bermuda.

Remarks. — This species has often been referred
to Thor paschalis (Heller), an Indo-west Pacific
form. Holthuis (1947) considered the West In-
dian species distinctive, and, in fact, it is the type
species of the genus. As far as known, T. -flori-
danus is not common in the Carolinas.

Ovigerous females have been reported (Broad,
1957c; Lunz, 1939; Verrill, 1922; Wass, 1955) or
are known from collections from April to August
in southeastern United States, Bermuda, and the
West Indies. In addition, they are known from
Cuba in November and January.

Broad (1957c) worked out the larval stages of
this form, using various species of algae as food
for the developing larvae. Though survival varied
with species of algae fed, he considered at least
certain species of algae to be an adequate diet for
survival, molting, and metamorphosis. Broad de-
scribed eight zoeal stages and a postlarval stage.
Comparison of these stages with earlier descrip-
tions by Lebour (1910) led Broad to question the
conspecificity of Thor from Bermuda and the
Carolinas.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Genus Latreutes Stimpson, 1860

Stimpson, 1860, p. 27.— Hemming, 1958b, p. 157.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace and rostrum unarmed dorsally except for a
single, small, median spine on gastric region ; rostrum
an elongate blade nearly as long as carapace

fucorum (p. 78).

aa. Carapace strongly humped and armed dorsally with
five or six spiniform teeth ; rostrum a deep ovoid blade,
shorter than carapace parvulus (p. 79).

Latreutes fucorum (Fabricius)

Figure 63

Palaemon fucorum Fabricius, 1798, p. 404.

Latreutes ensiferus: Hay and Shore, 1918, p. 390, pi. 26, fig. 13.
Latreutes fucorum: Verrill, 1922, p. 131, pi. 16, figs. 5-5b ;
pi. 42, figs. 2-2t ; pi. 44, figs. 1-lm, 2a-2n, 3 (rev.).

Recognition characters. — Rostrum thin, nearly
as long as carapace, smooth edged, broadest at
base and deepest near base, slightly concave
dorsally and upturned at tip, convex ventrally;
tip subtruncate and armed with about five to
seven small, acute spinules. Carapace smooth; a
small middorsal spine on gastric region; anterior
margin produced into an acute lobe below eye
followed ventrally by a wide, nearly rectangular
emargination and a series of four to nine small
denticles at anterolateral angle; a spine removed
from margin near suborbital lobe. Eyes well de-
veloped, with a tuberculate swelling antero-
medially near cornea. Antennular peduncle with
basal article excavate laterally ; stylocerite broad,
thin, cupped dorsally; distal spine on lateral
border of basal article reaching about to base of
third article; second and third articles short;
distal border of third obscurely denticulate, outer
flagellum thick at base. Antennal peduncle stout;
antennal scale wide at base, tapering to acute ter-
minal spine, scale about as long as rostrum. Third
maxilliped elongated, leglike; distal article long,
with eight or nine acute marginal spines.

First legs incurved, short, relatively stout, un-
equal ; larger chela thick, proximally broad, ovate,
tapering distally ; dactyl wide, longer than immov-
able finger, with broad lateral lobe and about three
denticles at tip; immovable finger bent slightly
inward and arched, tip subacute or slightly biden-
tate; fingers hairy; carpus large, cup-shaped,
broader than long; merus and carpus excavate
beneath. Second legs slender; chelae slender,
somewhat unequal ; fingers about as long as palm,

hairy at tip; carpus with three unequal joints,
middle one longest. Third to fifth legs long,
slender, subequal; propodi and dactyls with row
of spines on lower edge.

Abdomen smooth. Telson long, narrow, taper-
ing to narrow tip with spiniform median process
flanked by two pairs of unequal spines, inner pair
longer than median process; two pairs of dorsal
spines, at half and three-fourths of length.
Uropodal exopods with outer edge terminating in
a small sf>ine flanked medially by a movable spine.

Measurements.— Length of body: adults, 12 to
20 mm.; males smaller than females.

Variations. — The rostrum varies greatly in
length, depth, and number of spines (Wass, 1955).

Figure t>3. — Latreutes fin-mum (Fabricius). A, animal
in lateral view, x 17 (after Bate, 1888) ; B, antennal
scale, X 17; C, distal article of third maxilliped, X 42;
I). right first cheliped. X 17: E, left first cheliped, X
25 : F, second cheliped : X 17 : (i, distal articles of third
leg. x 1"; II, telson and uropods, X 17 (after Verrill.
1922).

FISH AND WILDLIFE SERVICE

Color. — Often nearly colorless and transparent;
sometimes with body pale yellow, yellowish green,
greenish brown, brown, red, black, black with
white spots and bars; bright blue patches on
dorsal and lateral surfaces; often mottled, striped,
or barred, and corresponding in pattern to irregu-
larly colored bits of weed (various authors).

Habitat. — Common in floating masses of Sar-
gassum; surface waters.

Type locality. — Floating gulfweed.

Knoivn range. — Newfoundland to Puerto Rico,
through Gulf of Mexico to Texas; Bermuda; near
the Azores and Cape Verde Islands; Cape of
Good Hope (?) (Holthuis, 1951b; Sivertsen and
Holthuis, 1956).

Remarks. — Ovigerous females have been ob-
served in inshore waters of the Carolinas and ad-
jacent western Atlantic region from July to
October. They have been observed in the Gulf
of Mexico from April to June. In the middle and
western Atlantic they have been observed in June
(Sivertsen and Holthuis, 1956). Gurney (1936a)
described the first stage larva.

Pearse (1952b) reported the parasitic Pro-
bopyrus latreuticola (Gissler) in the gill cavity
of this shrimp near Port Aransas, Texas.

Brown (1939) found four kinds of pigment in
this shrimp (white, red, yellow, and blue) similar
to pigments .found in Hippolyte, Leander, and
Palaemonetes species. The red and yellow pig-
ments respond to white background by concentra-
tion into the chromatophore centers and to black
background by dispersion into the chromatophore
branches. Latreutes has a great abundance of
white pigment which may vary in color from
yellowish white to clear white. Darkness pro-
duces concentration, and darkness or black back-
ground with low intensity of incident light calls
forth concentration of the reflecting white
chromatophores. Direct sunlight of a bright sky
produces dispersion of white pigment in spite
of black background. Blue patches on the animals
apparently consist of blue pigment accumulated in
particular white chromatophores. Brown con-
cluded that the different color patterns in this
species are not solely results of responses to
particular situations, but are at least partly
genetic patterns repressed or encouraged by light
intensity in color of the background. The re-

sponse is similar to responses in crustaceans hav-
ing far less ability to change color.

Latreutes parvulus (Stimpson)

Figure 64

Rhynchocyclus parvulus Stimpson, 1866, p. 48. — 1871b, p. 124.

Concordia gibberosus: Hay and Shore, 1918, p. 391, pi. 26,
fig. 11.

Latreutes parvulus: Holthuis, 1947, p. 59. — 1951b, p. 131, fig.
28 (rev.).

Recognition characters. — Rostrum laterally
compressed, almost circular in outline in female,
more elongate in male; upper margin with six to
eight teeth in female, two to four in male; a few
small teeth on tip; lower margin unarmed or
with up to five shallow teeth; ventral part of
rostrum produced somewhat backward. Carapace

Figure 64. — Latreutes parvulus (Stimpson). A, ovig-
erous female in lateral view, X 6; B, carapace of
ovigerous female in lateral view, X 6; C, carapace
of male in lateral view, X 6; D, antennule, X 13; E,
antennal scale, X 13; P, first leg, X 17; G, second
leg, X 17; H, third leg, X 17; I, telson and right
uropod iu dorsal view, X 17 (after Holthuis, 1951b).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

with middorsal row of five to seven small, erect
teeth, row starting somewhat anterior to middle
of carapace, extending to base of rostrum;
carapace somewhat swollen in female, making
an angle at base of middorsal row of teeth ; upper
margin nearly straight in males; anterior margin
with a narrow, anteriorly directed lobe forming
lower angle of orbit, a slender spine on lobe;
anterolateral angle serrate with two to four teeth ;
between anterolateral angle and lower margin of
orbit a row of three or four slender spines a bit
removed from and parallel to margin. Eyes well
developed ; cornea globular ; eyestalk with a trun-
cated process at upper inner margin overlapping
line separating cornea from stalk. Antennular
peduncle with stylocerite broad and rounded,
hollowed above and together with basal article of
penduncle forming concavity for reception of
eye; second article of peduncle much shorter than
third; upper flagellum shorter than lower, with
seven or eight broad and one or two narrow joints.
Antennal scale about twice as long as broad, over-
reaching antennular and antennal peduncles, but
not reaching end of rostrum; outer margin nearly
straight, ending in a small tooth reaching about
as far as lamella; a small spine on outer surface
of peduncle near base of scale.

First legs equal, short, thickset, slightly over-
reaching base of antennal scale ; fingers somewhat
shorter and narrower than palm, tips of fingers
ending in dark-colored nails; palm broadened
posteriorly; carpus somewhat conical, about as
long as palm. Second legs more slender, reaching
about to end of antennal peduncle; chelae with
fingers shorter than palm; carpus almost twice
length of chela, three-jointed, median joint long-
est; merus two-thirds as long as carpus. Third to
fifth legs with dactyls ending in a sharp tooth,
posterior margin with four comblike teeth pro-
gressively smaller proximally.

Abdomen smooth. Telson triangular; with two
pairs of dorsal spines at half and three-fourths
length; tapering to a narrow tip with spini-
form median process flanked by two pairs of
spines, Lnher pair longest; terminal portion with
feathered setae. Uropodal exopods with outer
margin ending in a small spine flanked medially
by a movable spine.

Measurement*. — Length of body: 7 to 12 mm.;
males smaller than females.

Variations. — Shape of the rostrum, as well as
its spination, is subject to some variation.

Habitat. — Littoral waters from (in?) sponges,
and among shells and hydroids; surface to 24
fathoms.

Type locality. — St. Joseph Island, Tex.

Known range. — Beaufort, N.C., to Texas;
Cuba; Puerto Rico; French Guiana; Rio de
Janeiro, Brazil ; Sierra Leone, "West Africa.

Remarks. — For many years this species has
been known as Concordia gibberosus Kingsley
or Lat rentes gibherosus (Kingsley). Holthuis
(1947) showed that these names fall into the
synonymy of Stimpson's species.

Latreutes parvulus is not known to be common
anywhere in its range. It has been taken through-
out the year in the Carolinas. Ovigerous females
have been taken throughout the year in various
parts of the range north of the equator and in
February in Brazil.

Genus Hippolyte [Leach, 1814]

Verrill. 1922, p. 124.— Holthuis, 1947, p. 53. — Hemming, 195Sb.
p. 157.

KEY TO SPECIES IN THE CAROLINAS

a. Basal article of antennular peduncles without distal
spines dorsally plciiracantlia (p. 80).

aa. Basal article of antennular peduncles with distal
spines dorsally zostericola (p. 82).

Hippolyte pleuracantha (Stimpson)

Figure 65

Virbiua pleuracanthua Stimpson, 1871b, p. 127.
Hippolyte pleuracantha- Hay and Shore, 191 S. p. 390. pi. 26.
fig. 8.— Holthuis, 1947, p. 15 (rev.).

Recognition characters. — Body smooth, with
tufts of plumose hairs on dorsal surface of cara-
pace and abdomen, tips of abdominal pleura, and
distal portion of eyestalks. Rostrum rather stout
at base, thin distally, slightly decurved, armed
dorsally with one to three teeth and ventrally
with one to three teeth near tip; tip reaching
about to end of antennular peduncle; a strong
spine on each side at base of rostrum. Anterior
margin of carapace produced into a lobe below
eye followed ventrally by an antennal spine, an
emargination at base of antenna followed by a
slightly produced, broadly rounded anterolateral
angle; hepatic spine strong. Eyes well developed.
Antennular peduncle with basal article long and
broad, stylocerite slender, lanceolate, reaching

FISH AND WILDLIFE SERVICE

Figure 65. — Hippolyte pleuracantha ( Stimpson ) . A, ani-
mal in lateral view, 3 mm. indicated ; B, anterior por-
tion of body in dorsal view; C, second leg; D, anterior
portion of body in lateral view; B-D, 1 mm. indicated.

about to middle of article and separated from
lateral border of article by about width of stylo-
cerite, article ending in a short, broad, elevated,
bladelike projection, a short spine at antero-
lateral corner under blade; second and third
articles much shorter than first; antennular
flagella of about equal length; outer ramus stout,
broadest in middle, tapering to slender distal
portion, hairy on ventral border. Antennal scale
large, exceeding rostrum and reaching nearly to
end of antennular flagella, length a little over
three times width ; outer margin slightly concave,
terminating in a small spine, spine exceeded by
lamella; a spine near base of scale.

First legs short, nearly equal, reaching a little
beyond base of distal article of antennal pedun-
cle; chelae setose, palm inflated, fingers about
half length of palm, cutting edges finely serrate;
carpus irregularly conical in shape, about three-
fourths length of chela, lower outer border with
spiniform setae. Second legs slender, reaching to

tip of antennular peduncle; carpus longer than
merus, divided into three joints; fingers two-fifths
length of chelae, tips of cutting edges with spines;
chelae hairy. Third to fifth legs long; third
reaching to tip of antennal scale; dactyls with
series of spines in comblike arrangement on inner
border; propodi spined on inner border.

Abdomen strongly bent at third segment;
posterior portion of third segment raised with
hoodlike projection overhanging fourth segment.
Telson with two pairs of dorsal spines on lateral
border, one about at half, another at three-fourths
length ; tip truncate, bearing three pairs of spines,
inner two pairs nearly equal, outer pair much
shorter. Uropodal exopods with lateral border
ending in a small spine flanked medially by a
movable spine.

Measurements. — Length of body: ovigerous fe-
males, 12 to 18 mm.; males somewhat smaller.

Variations. — The rostrum in this species varies
conspicuously in number of teeth, in shape from
lateral view, and in length. Dorsal and ventral
rostral teeth occur in all combinations from 1/1
to 3/3. Males are more slender than females.

Color. — Usually mottled brown or red, often a
bright green.

Habitat. — Extremely abundant in beds of vege-
tation (Zostera and Dipt ant Iter a) in sounds and
bays. Also found among rocks of jetties.

Type locality. — Norfolk Harbor, Va., and
Somers Point, Great Egg Harbor, N.J.

Known range. New Jersey to Galveston, Tex.;
Bermuda.

Remarks. — The two species, Hippolyte pleura-
cantha and H. zostericola, have been much con-
fused over the years, and it is not at all certain
that differences pointed out here adequately dis-
tinguish them. No attempt has been made here
to give complete synonymies. This task must be
approached by a thorough revisionary work in
which all existing collections are studied.

In general, it can be stated that H. pleuracantha
has no prominent distal spines on the basal article
of the antennular peduncle; it has a relatively
shorter rostrum, and appears to be somewhat
larger than H. zostericola. Hippolyte zostericola
has a prominent, distal, dorsal pair of spines on
the basal article of the antennular peduncle. I am
much indebted to L. B. Holthuis for pointing out

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

the latter character to fellow workers on the
American coast.

Because identifications in the literature are
probably confused, the geographic limits of the
species given here must be regarded with re-
serve.

Ovigerous females of H. pleuracantha occur in
North Carolina at least from April to October in
the Beaufort area. Gurney (1936b) pointed out
some differences between adults of H . pleuracantha
and H. zostericola (as well as other species of
Hippolyte) and described four larval and two
postlarval stages of what he considered to be a
Bermudian subspecies, H. pleuracantha bernvw-
densis.

Hippolyte zostericola (Smith)

Figure 66

Virbius zostericola Smith, 1873c, p. 550, pi. 3, fig. 11.
Hippolyte zostericola: Holthuis, 1947, p. 16.

Recognition characters. — Body smooth. Ros-
trum rather stout at base, thin distally, slightly
decurved, armed dorsally with three or four teeth
and ventrally with two to five teeth distally;
tip reaching beyond antennular peduncle and of-
ten nearly to tip of antennal scale; a strong
spine on each side at base of rostrum. Anterior
margin of carapace produced into a prominent
narrow lobe below eye followed ventrally by an
antennal spine; a shallow emargination at base
of antenna and a broadly rounded anterolateral
angle; hepatic spine well developed. Antennular
peduncle with basal article long and broad,
stylocerite slender, divergent at tip and well
separated from article, basal article terminating
in a pair of well-developed spines on anterolateral
corner; second and third articles much shorter
than first; antennular flagella of about equal
length, outer ramus stout basally, tapering to
slender distal portion, hairy on ventral border.
Antennal scale large, slightly exceeding rostrum
and reaching nearly to end of antennular flagella,
length a little over three times width; outer
margin slightly concave, terminating in a small
spine, spine exceeded by lamella; a spine near
base of scale.

First legs short, nearly equal, reaching base
of distal article of antennal peduncle; chelae
lightly setose, palm inflated, fingers about
half length of palm, cutting edges finely serrate;

Figure 66. — Hippolyte zostericola (Smith). A, anterior
portion of body in dorsal view ; B, anterior portion of
body in lateral view ; 1 mm. indicated.

carpus irregularly conical in shape, about three-
fourths length of chela, lower outer border with
spiniform setae. Second legs slender, reaching
to distal end of basal article of antennular pe-
duncle; carpus longer than merus, divided into
three joints; fingers about two-fifths length of
chelae, tips of cutting edges with spines; chelae
hairy. Third to fifth legs long; third reaching
to tip of antennal scale; dactyls with series of
spines in comblike arrangement on inner border;
propodi spined on inner border.

Abdomen strongly bent at third segment;
posterior portion of third segment raised with
hoodlike projection overhanging fourth segment.
Telson with two pairs of dorsal spines on lateral
border, one at half, another at three-fourths
length ; tip truncate, bearing three pairs of spines,
inner two pairs about equal, outer pair much
shorter. Fropodal exopods with lateral border
ending in a small spine flanked medially by a
movable spine.

FISH AND WILDLIFE SERVICE

Measurements. — Length of body: ovigerous fe-
males, 10 to 12 mm. ; males somewhat smaller.

Variations. — The rostrum in this species varies
considerably in number of teeth, shape from lateral
view, and relative lenfeth. Dorsal and ventral teeth
have been observed in the combinations 3/3, 3/4,
3/5, 4/2, 4/4, and the range of variation may be
greater than this because only a few specimens
from the Beaufort, N.C., area have been studied.
Males are more slender than females.

Color. — Bright green, pale or translucent tinged
with green; sometimes specked with reddish
brown and with a broad median band of dark
brown extending whole length of body (Smith,
1873c).

Habitat. — Beds of vegetation such as eelgrass.

Type locality. — Vineyard Sound, Mass.

Known range. — Southern Massachusetts,
through Gulf of Mexico and West Indies to
Curacao (Holthuis, 1947).

Remarks. — Differences between this species and
H. pleuracantha are discussed in the account for
H. pleuracantha. Ovigerous females have been
found in North Carolina in September.

Genus Tozeuma Stimpson, 1860

Stimpson, 1860, p. 26. — Holthuis, 1955, p. 112 (rev.).

Tozeuma carolinense Kingley. Arrow shrimp
Figure 67

Tozeuma carolinensis Kingsley, 1878b, p. 90. — 1880, p. 413. —
Schmltt, 1935a, p. 155.

Tozeuma carolinense: Rathbun, 1901, p. 114. — Hay and Shore,
1918, p. 391, pi. 27, fig. 2.

Angasia carolinensis: Holthuis, 1947, pp. 17, 61.

Recognition characters. — Body elongate, com-
pressed. Rostrum slender, almost twice as long as
remainder of carapace, inclined slightly upward
distally, rounded and unarmed dorsally, base some-
what flattened and horizontal, deepest anterior to
orbit and decreasingly lamellate distally ; ventral
border with many appressed teeth. Carapace
smooth, polished; a strong spine at either side
of base of rostrum; anterior margin produced
into a triangular tooth below eye; anterolateral
angle with a spine. Eyes well developed. Anten-
nular peduncle rather slender; first article longest,
with slender stylocerite slightly exceeding distal
border; second and third articles progressively
shorter; outer flagellum thick and much shorter
than inner, neither quite reaching tip of antennal
scale. Antennae longer than rostrum; antennal

scale lanceolate, less than half length of rostrum ;
basal antennal article with a strong ventrolateral
spine on anterior border.

Legs relatively short; first pair very short,
stout, hand inflated, fingers curved, closing com-
pletely, spines on fingers dark colored; second
pair slender, longer, carpus with three joints,
proximal joint nearly as long as merus; legs three
to five with comblike spines on curved dactyls.

Abdomen smooth; strongly bent between third
and fourth segments; third segment of male
bearing a low dorsal hump ; fifth segment with a
spine at each side of posterior border; sixth with
a spine at posterolateral angle and a broad spine
at base of telson. Elements of tail fan long and
narrow. Telson with one pair of dorsal spines
at midlength, another at three-fourths length;
tip with a strong pair of median spines flanked
by a weak lateral pair. Uropodal exopods with
outer border terminating in a small spine flanked
medially by a movable spine.

Measurements. — Length of body : ovigerous fe-
males, 28 to 50 mm.

Variations. — The humped third abdominal seg-
ment is pronounced in young individuals of both

sexes.

Color. — Apparently varying to some degree
depending on background; shades of green from
light yellowish green to rich deep green, or oc-
casionally brownish or red in beds of Diplanthera
wrightii and Zostera marina (Bryce, 1961) ;
purple on alcyonarian corals Antillogorgia and
Pterogorgia (Voss, 1956) ; nearly colorless (Ver-
rill, 1922).

Figure 67. — Tozeuma carolinense Kingsley. Female in
lateral view, 10 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Habitat. — Common in beds of vegetation or
similar habitats in shallow water, this species
often swims in a vertical position and rests in a
clinging position on blades of grass. It blends
well with the background because of shape and
color and is aptly named "arrow shrimp". Sur-
face to 41 fathoms (Holthuis, 1947).

Type locality. — Fort Macon, N.C.

Known range. — Vineyard Sound, Mass., to
Colon, Panama ; through West Indies to Curasao.

Remarks. — Bryce (1961) gave general ecologi-
cal observations on T. carol ineme along with a
detailed study of larval development. The adults
apparently feed by grazing on faunal and floral
growths on marine grasses.

In Xorth Carolina, ovigerous females are pres-
ent from May to October, with one doubtful record
in February. Elsewhere they have been taken in
February from Bimini, March to November in
Florida and Louisiana, and in December from
Puerto Rico.

Bryce found that larvae hatched from ovigerous
females and reared in culture dishes usually
passed through eight or nine larval stages before
metamorphosing into postlarvae. However, the
larvae did not always transform at these stages,
and, in one group reared in early fall, continued
molting for an indefinite number of stages. One
individual passed through 25 larval stages before
the experiment was terminated. Variations in
larval stages and examples of asymmetry were
discussed, as were the effects of diet and tempera-
ture.

Genus Hippolysmata Stimpson, I860

Stimpson, lsfiO, p. 26. — Holthuis. 1955, p. 115. — Hemming,
1958b, p. 156.

KEY TO SPECIES IN THE CAROLINAS

a. Rostrum not exceeding antennular peduncles

H'ltnh manni I p. 84 i .
aa. Rostrum greatly exceeding antennular peduncles

oploph oroides i p. 85 i .

Hippolysmata (Hippolysmata) wurdemanni (Gibbes)
Figure 68

Hippolytc wurdemanni Gibbes, 1850, p, 197,
Hippolysmata wurdemanni: Hay ami Shore, 1918, p. 392, pi.
26, flg. 12.

Recognition characters. — Rostrum reaching <Jis
tal end of second article of antennular peduncle,

Figure 68. — Hippolysmata (Hippolysmata) wurdemanni
(Gibbes). A, anterior portion of body in lateral view:
B, antennule; C. antenna! scale; D, second leg; E, uro-
pods and telson in dorsal view ; A-E. 5 mm. indicated.

slightly decurved, armed dorsally with four or
five teeth and ventrally with three to five teeth
Carapace smooth; carinate dorsally on anterior
half with a spine near base of rostrum about
midway between rostral tip and posterior border;
anterior margin with a strong antennal spine;
anterolateral corner rounded. Eyes well de-
veloped. Basal article of antennular peduncle
large, stylocerite slender, flattened, pointed,
reaching a little beyond middle of article; second
and third articles progressively shorter; inner
flagellum slender; outer flagellum with about 20
lo. ".(I thickened basal joints. Antenna! scale long.
narrow; outer margin about straight, terminating
in a strong spine; lamella of scale truncate dis-
tallv. about equal lo spine.

Epipods on lirst four pairs of Legs. First legs
stout, about equal, reaching to cud of antennal

FISH AND WILDLIFE SERVICE

scale; fingers about one-third length of palm,
spines at tips of fingers darkened; carpus and
hand of nearly equal length. Second legs much
longer, slender; chela small; carpus divided into
about 30 joints, last joint longest. Third to fifth
legs not so slender as second ; dactyls with a few
coarse spines on inner border.

Abdomen smooth; posterolateral angle of fifth
and sixth segments acute. Telson tapering to
nearly truncate tip with a minute median projec-
tion flanked by two long, slender spines and
outside these a short spine on each side; armed
dorsally with two pairs of dorsal spines, anterior
pair at one-third length, posterior pair at two-
thirds length. Uropodal exopods with outer
margin ending in two distinct teeth, between these
a slender movable spine.

Measurements. — Length of body: males, 28 to
54 mm.; ovigerous females, 38 to 55 mm. (Wass,
1955, in part).

Variations. — Individuals from the northern
extreme of the range differ in some respects from
those in South America (Holthuis, 1959). The
rostrum in South American specimens has four
to seven dorsal teeth, and in specimens from the
United States, four or five. Some southern speci-
mens have stylocerites nearly as long as the basal
antennular articles. In southern specimens, the
tip of the lamella on the antennal scale is more
truncate than in northern specimens. The second
leg in Guiana material is more slender than in
northern material, and the number of articulations
in the carpus is higher, 33-37 as opposed to
27-31.

Color. — Translucent white with beautiful longi-
tudinal and transverse markings of red.

Habitat. — Commonly found on stone jetties or
among hydroids growing on piles or buoys; sur-
face to 16 fathoms.
Type locality. — Key West, Fla.
Known range. — Lower Chesapeake Bay to
Port Aransas, Tex.; Surinam; French Guiana;
Mamanguape, Sao Paido, Brazil.

Remarks. — Ovigerous females have been re-
ported in January from Florida and in May from
the Guianas (Holthuis, 1959; Wass, 1955). They
have been collected in April and August from
North Carolina, and in August from Louisiana.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 0^65 7

Subgenus Exhippolysmata Stebbing, 1915

Stebblng, 1015, p. 94.

Hippolysmata (Exhippolysmata) oplophoroides Holthuis

Figure 69

Hippolysmata (Exhippolysmata) oplophoroities Holthuis 1948
p. 1106.— 1959, p. 112. fig. 17.

Recognition characters.— Rostrum long, slender,
directed somewhat upward, reaching beyond an-
tennal scale by nearly half of length; basal por-
tion elevated into a crest bearing 9 to 10 closely
placed teeth, one tooth some distance behind
crest, remainder of upper margin with 1 to 6
widely separated teeth; ventral margin with 10
to 14 teeth. Carapace, coarsely pitted; anterior
margin produced into a slight lobe below eye
closely followed ventrally by an antennal spine;
a pterygostomian spine at anterolateral angle.
Eyes well developed. Basal article of antennular
peduncle with stylocerite rather broad and
pointed, reaching beyond middle of article; second
article somewhat longer than third; upper fla-
gellum simple with about 20 to 25 basal joints
thickened, hairy below. Antennal scale almost

Figure 69. — Hippolysmata (Exhippolysmata) oplophoro-
ides Holthuis. A. anterior portion of body in lateral
view, x 3.5; B, antennal scale. X 4; C, second leg, X 4;
D, abdomen in lateral view, X 3.5; E. telson and right
uropod in dorsal view, X 3.5 (after Holthuis, 1948).

three times as long as broad ; outer margin slightly
concave, ending in a strong tooth; lamella of
scale exceeding spine; outer spine near base of
scale directed ventrally.

Epipods on first four pairs of legs small but
distinct. First legs equal, reaching somewhat be-
yond end of antennal peduncle; fingers short and
blunt, immovable finger ending in a dark colored,
sharp point fitting between two dark points on
end of dactyl, outer surface of fingers convex,
inner surface concave, fingers about five-eighths
length of palm ; carpus slightly shorter than chela
and three-fourths length of merus. Second legs
slender; slightly unequal in size, reaching almost
to end of third maxilliped; chela small and
slender; carpus five times length of chela and
divided into 13 to 15 joints, first and last joints
longest. Third to fifth legs slender; dactyls
simple.

Abdomen coarsely and shallowly pitted; third
segment with a dorsal carina ending in a strong,
posteriorly directed spine; pleura of second to
fourth segments produced postero vent rally in a
narrowly rounded tip, pleura of fifth and sixth
ending in a distinct sharp tooth; posterolateral
angle of sixth spiniform. Telson tapering grad-
ually to a slender point; dorsal surface with two
pairs of spines, anterior pair at one-third length,
second pair closer to first pair than to tip.
Uropods elongate ; outer margin of exopod ending
in two distinct teeth, between these a slender
movable spine.

Measurements.— Length of body : ovigerous fe-
males, 47 to 79 mm.

Variations. — In the case of a rostrum with one
distal tooth dorsally, there were suggestions of
three other small, malformed teeth.

Color. — General color pink; rostrum and an-
terior part of carapace pink, posterior part of
carapace white and yellowish; abdomen white
with pink most pronounced along posterior mar-
gins of first to fourth segments, spine on third
segment almost red, fifth and sixth segments
entirely pink; tail fan red, pink at base; anten-
nular and antennal flagella pink; legs red, some-
times purplish distally ; pleopods red; eggs yellow
or greenish (Holthuis, 1959).

Habitat. — The species has been taken near shore,
often in estuaries (15.89 °/ot> over mud bottom)
(Holthuis, 1!);.!)) ; 4 to 15 fathoms.

Type locality. — Mouth of Suriname River near
Resolutie, Surinam.

Known range. — Off Cape Fear River, N.C., to
Port Aransas, Tex.; British Guiana to Santos
Harbor, Sao Paulo, Brazil.

Remarks. — Most information on this recently
described species is summarized in Holthuis'
(1959) account. Ovigerous females have been re-
ported from December to July in South America
and from August to October in the Carolinas.
The species is more abundant than Xiphopenew
in British Guiana but apparently less abundant to
the eastward in the other Guianas. Records from
the United States are sporadic.

Family Processidae

Rostrum horizontal with dorsal surface of cara-
pace. First pair of legs asymmetrically chelate;
first leg of one side ending in a simple clawlike
dactyl. Second pair of legs minutely chelate;
slender ; with segmented carpus.

Genus Processa Leach, [1815]

Holthuis, 1955. p. 116 (rev.). — Hemming, 1958b, p. 143.

Processa bermudensis (Rankin)
Figure 70

Nika bermudensis Rankin, 1900, p. 536.

Processa eanalieulata: Verrill, 1922, p. 138. — Schmltt, 1935a,
p. 169 (part).

Proeessa bermudensis: Gurney, 1936c, p. 624, figs. 44—52
(rev.). — Lebour, 1941, p. 410, figs. 28-33. — Holthuis, 1959,
p. 120.

Recognition characters. — Rostrum slender, near-
ly straight, extending about two-thirds length
of eye, bifid at end with upper process shorter
than lower, a few hairs between tips. Carapace
lacking antennal spine; anterior border rounded,
somewhat sinuous. Eyes large, shorter than basal
antennular article. Antennular peduncle with
basal article excavate dorsally, longer than suc-
ceeding two articles combined, stylocerite short,
somewhat truncate; second article about half
again as long as third; inner flagellum filiform;
outer flagellum thick, fusiform at base, slender
distally, hairy, about as long as peduncle. An-
tennal scale about six times as long as wide; sides
nearly parallel, truncate terminally; lateral spine
small, slightly exceeding lamella; antenna a little
longer than body. Third maxilliped with ter-

FISH AND WILDLIFE SERVICE

Figure 70. — Processa bermudensis (Rankin). Animal in
lateral view (after Rankin, 1900).

minal article and a portion of adjacent article
extending beyond antennular peduncle.

First pair of legs strong ; chelate on right side ;
carpus a little over one-third length of merus,
length about 1.5 times width; palm 1.5 times
length of dactyl; left leg not chelate, carpus
three times as long as wide and about two-thirds
length of propodus. Second legs long, slender,
unequal, chelate; carpus and merus subdivided;
right leg with 18 carpal, 12 meral joints; left
leg with 17 carpal, 6 meral joints; merocarpal
bend of right leg reaching to or beyond end of
antennal scale. Remaining legs long, slender;
third shortest; fourth slightly longer than fifth;
dactyls simple ; propodus of fifth leg with groups
of long setae, a single small spine at end and one
to five additional spines along article.

Abdomen with pleura rounded. Telson three
times as long as basal width; two pairs of large
dorsolateral spines, first pair close to anterior
end; tip subacute, armed with two pairs of stout
spines, and a strong median pair of feathered
setae, outer spines short, intermediate spines
long. Uropods elongate; outer border of exopod
ending in an acute spine flanked medially by a
strong movable spine.

Measurements. — Length of body: males 14 to
16 mm. ; females, 50 mm.

Variations. — The first pair of legs is usually
chelate on only the right side but this asymmetry
may be reversed. Relative length of the carpus
of the first legs changes with age.

Color. — Larvae pale brown with glistening
white chromatophores; whole body pale (Lebour,
1941).

Habitat. — Oceanic water; surface to possibly
180 fathoms.

Type locality. — Harrington Sound, Bermuda.

Known range. — Bermuda; North Carolina (re-
stricted to recently identified material).

Remarks.— Gumey (1936c), Lebour (1941), and
Holthuis (1959) have all pointed out the confu-
sion which exists concerning identity of the
species of Processa in the Western Atlantic.
Formerly, the species found in the Western Atlan-
tic were lumped under the name P. canalicvlntn.
a name now restricted to a species in European
waters (Lebour, 1936), but Lebour (1941) showed
that three or perhaps four species occur at
Bermuda. It is likely that more than one species
occurs in the Carolinas as well.

From descriptions given by the above authors,
it appears that one species occurring in the
Carolinas is P. bennudensis. a species lacking
antennal spines, although the stylocerite in North
Carolina material is not shaped exactly as that
shown in Gurney's illustrations. In addition,
there is apparently a second species (represented
by a few immature specimens in the Institute of
Fisheries Research collection, all taken in night
plankton tows in Bogue Sound) which has an an-
tennal spine present, shorter legs than P. bermu-
densis. fewer joints in the carpi of the second
legs than the above, and exhibits considerable
variation in spination of the third and fourth
legs. These specimens appear to be close to
Lebour's P. wheeleri, but because they are so few
in number and immature it is best to reserve
determination until more material is available
for study.

Lebour (1941) showed that P. bermudensis
larvae are common in the plankton almost
throughout the year in Bermuda, and adults were
commonly found in the dredge at night, with
ovigerous females occurring at least from June
to October. Gumey ( 1936c) described eight larval
stages.

Pearse (1934) too P. "canaliculata" from log-
gerhead sponges at Tortugas, Florida.

Family Pandalidae

Rostrum long and slender, laterally compressed,
armed with teeth or spines. Eyes well developed.
Mandibles with incisor process and a two or three-
jointed palp. First pair of legs simple or
microscopically chelate; second pair long, slender,
chelate, carpus subdivided.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Genus Pantomus Milne Edwards, 1883

Rathbun, 1901. p. 117.— Hemming, 1958b, p. 159.

Pantomus parvulus Milne Edwards

Figure 71

Pantomus parvulus Milne Edwards, 1883, pi. 26. fig. 1, la. —
Rathbun, 1901, p. 118. — Scnmitt, 1935a, p. 138.

Recognition characters. — Rostrum longer than
carapace, articulated with anterior margin of
carapace; basal portion with three dorsal spines;
lower margin with numerous slender overlapping
spines; terminal half directed upward; tip bifid,
lower prong longest. Carapace carinated on an-
terior half and armed with three spines, posterior
two near together and movable, anterior spine
adjoining articulation of rostrum; antennal and
pterygostomian spines present. Eyes large. An-
tennular peduncle with basal article excavate
above and longer than nearly equal second and
third articles combined ; stylocerite wide, broadly
pointed, inner margin sinuous, tip reaching to
midlength of cornea ; upper flagellum about twice
diameter of lower flagellum at base. Antennal
scale, slender, reaching two-thirds length of ros-
trum, broadest near base; lateral spine exceeded
by lamella.

Third maxilliped and first pair of legs reaching
to tip of antennal scale. Second pair of legs longer
than first; carpus subdivided; one leg with 15
to 17 carpal joints, other leg shorter, with 10 to
12 carpal joints. Third to fifth legs progressively
longer than second pair.

I'm. i be 71. — Pantomus parvulus Milne Edwards. Animal
in lateral view i after Milne Edwards, 1883).

Abdomen with third segment broadly carinated
on posterior half; sixth segment elongate, 2.5
times length of fifth. Telson nearly as long as
sixth segment, slender; sides concave, tapering to
tip ending in a small, median, bulblike enlarge-
ment; two pairs of spines at tip, outer pair
longest and sinuous at base, inner spines shorter,
arising on terminal bulb ; a row of seven or eight
small dorsolateral spines on each side in distal
two-thirds of length. Uropods long, narrow;
exopod with lateral border ending in a slender
movable spine.

Measurements. — Length of body: ovigerous fe-
male, approximately 30 mm.

Variations. — Among four of the cotypes, the
rostrum varies somewhat in length and the num-
ber of carpal segments in the second legs is
subject to variation.

Habitat. — Seventy-five to 248 fathoms.

Type locality. — Northern part of Yucatan
Bank, lat. 23°13' N. long. 89°16' W., 84 fathoms.

Known range. — Cape Lookout, N.C., to Yuca-
tan, Mexico ; Puerto Rico ; St, Croix, V.I.

Remarks. — The Catalogue of the Books, Manu-
scripts, Maps and Drawings in the British Mu-
seum (Natural History), vol. VI, Supplement,
1922, lists Milne Edwards' 1883 paper as follows:
''The title-page ( wanting to this copy ) , the 'Liste
des Planches,' and many of the plates themselves
are lithographed. Only fifty copies were issued
and sent mostly to fellow workers, but a few were
sold, (See letter by the Author in 'Ann. and Mag.
Nat. Hist,' Vol. vi, 1890, p. 471)."

Family Crangonidae

First pair of legs subchelate,. stouter than
second. Second pair of legs slender, equal ; carpus
not subdivided; minutely chelate or simple.
Rostrum small, usually dorsally flattened, not
toothed.

Genus Crangon Fabricius, 1798

Holthuis, 1955, p. 134. — Hemming. 1958b, p. 108.

The name Crangon confused with the name
Alpheus during the first half of this century, had
doubtful status until nomenclatural stability was
effected by the International Commission on Zoo-
logical Nomenclature (Opinion 334)'. The Official
List of Generic Names in Zoology (Hemming,

FISH AND WILDLIFE SERVICE

1958b) now lists Oromgon Fabricius, 1798, as the
correct generic name for the species here con-
sidered, and the Official Index of Eejected and
Invalid Generic Names in Zoology (Hemming,
1958a) lists the suppressed generic name Crangon
Weber, 1795, and the invalid name Crago La-
marck, 1801, formerly applied to the species here
considered.

Crangon septemspinosa Say

Figure 72

Crangon septemspinosa Say, 181S, p. 246.

Craqo septemspinosa: Hay and Shore, 1918, p. 396, pi. 27,
fig. 9. — Rathbun, 1929, p. 20.

Recognition characters. — Rostrum shorter than
eyestalks, unarmed, tip obtuse. Carapace some-
what depressed, subcylindrical ; dorsal surface
with a small appressed spine back of rostrum;
anterior margin with suborbital spine obtuse;
antennal spine strongly produced, equaling or
slightly exceeding eyes and with a minute spine
below; hepatic spine well developed; anterior
portion of carapace with two impressed lines, one
originating in fissure in superior margin of orbit,
another originating lateral to suborbital spine,
both uniting above hepatic spine and disappearing
posteriorly; a broad groove below and anterior
to hepatic spine. Eyes moderately developed.
Antennular peduncle with basal article hollowed
out above, stylocerite broad, cupped longitudinally
forming portion of socket for reception of eye, tip
reaching nearly to end of article ; second article of
peduncle slightly shorter than third; inner
flagellum hairy below, a little longer than antennal
scale; outer flagellum shorter, smooth. Antennal
scale broadest in posterior half, lamella tapering

to narrow rounded tip; lateral border slightly
convex; well -developed lateral spine exceeding
lamella and as long as distal width of blade.
Third maxilliped reaching nearly to tip of an-
tennule; hairy.

First pair of legs strong, subchelate; hand less
than 3.5 times as long as wide, palm with a strong
spine at distal end of finger; merus with a small
spine on lower margin. Second pair of legs almost
filiform ; minutely chelate, hand hairy. Third legs
stronger; fourth and fifth normal.

Abdomen, viewed dorsally, tapering from broad
first and second segments to narrow sixth seg-
ment. Telson slender, tapering; with four small
spines above on lateral border, first pair at two-
thirds length, second midway between these and
acute tip; tip flanked by three pairs of movable
spines, median pair longest and stoutest. Uropodal
exopods with lateral border ending in a spine
flanked medially by a longer movable spine.

Measurements. — Length of body: ovigerous fe-
males from North Carolina, 25 to 60 mm. Speci-
mens from Delaware : males, to 47 mm. ; females,
to 70 mm. (Price, 1962).

Color. — Ash-gray with numerous irregular,
stellate, blackish-brown spots or speckled with
gray, imitating the color of sand; color subject to
considerable variation in shade, tail often darker
(various authors).

Habitat. — Usually near bottom over sand : low-
water mark to 50 fathoms, rarely to 246 fathoms.

Type locality. — "Bay shores and inlets of the
sea" [east coast of United States] .

Known range. — Baffin Bay to east Florida;
Arctic Alaska southward to Shumagin Islands,
Alaska, and Ranshima, Hokkaido, Japan.

Figure 72. — Crangon septemspinosa Say. Ovigerous female in dorsal view, legs of left side not shown, 10 mm.

indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Remarks. — At the time of Hay and Shore's ac-
count, it was apparent that C. septemspinosa, with
northern rather than southern affinities, fluctuates
in abundance seasonally in estuaries near Beau-
fort, N.C. Ovigerous females have been found in
North Carolina from December through May and
in August and late fall (Hay and Shore, 1918,
in part). Individuals taken in winter are larger
than those found in spring. Juveniles have been
found in this region from December to July, but
from midsummer to late fall juveniles and adults
disappear from estuaries.

Bigelow and Sears (1939) reported much the
same pattern of occurrence in waters of the Con-
tinental Shelf from Cape Cod to Chesapeake
Bay, with greatest occurrence in February dwin-
dling to rare occurrence in July, but never abun-
dant anywhere. They found the species limited,
probably by depth and not by distance from shore,
at about the 27- fathom curve, and remarked on
probable importance of the species in the diet of
predatory fishes. The role of the species in diets
of fishes has long been recognized (Whitley,
1948).

On Georges Bank, where Whitley (1948) made
all collections inside the 100-fathom curve, C.
septemspinosa was most common in September
and January, rarest in June, and usually occurred
near the bottom. He reported maximum numbers
in July at Woods Hole, and in August in the Bay
of Fundy. Ovigerous females were found in
spring and early summer. The species was judged
to produce one brood a year and to have a life
span of 1 year.

Price (1962) , studying the biology of C. septem-
spinosa in Delaware Bay, made collections in a
salinity range of 4.4 to 31.4 °/00 at temperature
extremes of 0.0° to 26.0° C. Growth rate was esti-
mated to be 1.6 mm. per month, with no observed
seasonal variation in rate. The major breeding
season was judged to be March to October, but
ovigerous females were found throughout the
year in salinities of 17.7 to 29.3%0, and tempera-
tures of 0.0° to 25.0° C. First egg bearers of
the year were found to be large females, with
smaller ovigerous females more numerous in July.
Females outnumbered the males, especially during
the most active spawning season. At 21° O, eggs
hatched after 6 or 7 days in the laboratory.

Contrary to the appraisal of other authors, Price
judged that 3 year classes of females and 2 year
classes of males occur in the shoal waters of Dela-
ware Bay in spring. Food studies indicated a diet
of planktonic Crustacea and scavenged material.
Sanders, Goudsmit, Mills, and Hampson (1962)
found a diet of small bottom plants and animals.

Fish (1925) found the larvae appearing from
February to May and as late as December at
Woods Hole. Needier (1941) recorded hatching
times from late spring to early summer (July)
around Prince Edward Island, Canada. She de-
scribed five larval stages and a postlarval stage.
All these stages were obtained in July from
plankton tows made about a meter below the sur-
face along the shores of estuaries. Larvae were
hatched in the laboratory, but the series of stages
was worked out from plankton.

These data indicate an extended breeding sea-
son in high latitudes. Variations in seasonal
abundance in different localities north of Chesa-
peake Bay are possibly the result in part of varied
sampling methods in different years by different
investigators.

Work on color control of Crangon and related
species, too involved for appropriate summary
here, has been reviewed by Kleinholz (1961).

Suborder Reptantia

Usually lobsterlike or crablike in form. Cepha-
lothorax usually depressed. Kostrum usually small
or absent, depressed if present. Antennules with-
out stylocerite. Legs strong, first pair usually, but
others never, stronger than remainder. Abdomen,
whether well developed or greatly reduced, more
or less depressed with first segment distinctly
smaller than rest ; pleopods often reduced or ab-
sent.

Section Macrura

Abdomen straight, symmetrical; usually well
armored, with well-developed pleura and a strong
tail fan (Schmitt, 1921).

Superfamily Scyllaridea

First article of antennule fused with epistome.
Antenna] scale absent. All legs nearly equal in
length and none chelate except subchelate last
pair in females. First abdominal segment without

FISH AND WILDLIFE SERVICE

pleopods; tail fan divided into a soft membranous
and striated hinder part and a harder anterior
portion.

Family Palinuridae

Carapace subcylindrical. Eyes not enclosed in
separate orbits formed by edge of carapace. An-
tennae not flattened but furnished with large,
long, rather rigid, multiarticulate, usually spinose
flagellum.

The fossil record for the family Palinuridae.
extends back to the Cretaceous in North America
(Rathbun, 1926, 1935).

Genus Panulirus White, 1847

White, 1847b, p. 69. — Hemming, 19581), p. 174.

Panulirus argus (Latreille). Spiny lobster, crawfish
Figure 73

Palinurus argus Latreille, 1804, p. 393.

Panulirus argue: White, 1847b, p. 69.— Hay and Shore, 1918,
p. 398, pi. 28, fig. 3 (rev.). — Crawford and deSmidt, 1922, p. 291,
figs. 265-271.— Schmitt, 1935a, p. 172, fig. 36 (rev.).

Recognition characters. — Carapace covered
with strong spines arranged more or less in regular
longitudinal rows ; spines above orbits very large,
compressed, and curved upward and forward.

Eyes large and prominent. Antennules nearly
two-thirds length of body; peduncles slightly
exceeding antennal peduncle; outer flagellum
shorter and thicker than inner, and strongly cili-
ated distally. Antennal segment with a pair of
spines in front, a weaker pair about halfway to
eye, a strong median spine and weaker lateral
spines below insertion of antennules. Antennae
very large, heavy, exceeding body by more than
length of carapace; peduncles with numerous
strong spines; flagellum stout, stiff, a line of cilia
along inner margin and ringed with spines at
intervals.

Legs rather weak, tips acute and bristly ; female
possessing a small subchela on fifth legs with con-
cave opposed surfaces formed between distal por-
tion of propodus and proximal portion of dactyl.

Abdomen smooth, each segment crossed by a
furrow more or less distinctly interrupted at mid-
dle; pleural angles each produced into a strong,
sharp, backwardly directed tooth deeply notched
and serrated on posterior margin. Pleopods ab-
sent from first segment of abdomen; exopod of
pleopods broad, laminate; endopods missing in
males, females with endopods of second pleopods
laminate, last three endopods bifurcated. Proxi-

Fiqube 73. — Panulirus argus (Latreille). Female in lateral view, approximately X 0.5.
MARINE DECAPOD CRUSTACEANS OF THE CAROLLNAS

raal division of telson with rather strong spines;
distal division with weak spines and cilia in longi-
tudinal lines. Uropods hard proximally, mem-
branous distally; basal article bispinose, a row of
denticles along margin of hard part, and lines of
minute spines and setae on upper surface of mem-
branous part.

Measurements. — Length of body from orbit to
tip of telson: to approximately 450 mm. (18
inches), occasionally larger.

Variations. — Aside from individual variations
which will not be discussed here, the species ex-
hibits marked allometric variations with age as
well as sexual dimorphism. These features were
discussed in detail by Crawford and deSmidt
(1922) and are summarized here. Antennae of the
young are longer in proportion to the body than
in adults. Setae present on the young disappear in
the adult and the sharpness of spines on the body
tends to diminish with age, except for those on
anterior portions of the carapace.

As pointed out in the description, only the fe-
males have chelate fifth legs. In adult males, the
second pair of legs is extraordinarily developed.
They are long, rarely used in walking, and the
dactyl is long, curved, and provided with a brush
of setae. The length of the dactyl, its curvature
and set at ion increase with age. Sexual differ-
ences in the pleopods are given in the description.

Males have a relatively more inflated and
longer carapace than females. Conversely, in fe-
males the abdomen represents a greater propor-
tion of total length of the body than in males.
Maximum lengths of the two sexes, however, are
about the same (Creaser, 1952). The posterior
margin of the sternum in males is narrower than
the comparable structure in females and the ster-
num is longer.

Color. — Coloration largely separable into two
groups, (1) lightly colored individuals ranging
from light gray and tan to shades of green and
light brown, and (2) darkly colored individuals
varying from shades of red to deep brown and
blue. Abdomen spotted witli yellowish ocelli;
posterior margin of each segment edged with yel-
low or orange, lower angles of segments marked
with bluish or greenish tints and sometimes addi-
t ional colors. Tail fan crossed by bands of orange,
yellow, and black, fringed with white. Pleopods
usually orange, about half of surface covered by

a black blotch. Legs striped longitudinally with
blue. Ventral surfaces of body light yellow ; tho-
racic sternum marked with irregular radiating
stripes.

Young with coloration of carapace arranged in
transverse bands, usually three, middle one dark;
antennae frequently ringed with alternate light
and dark bands; legs ringed with blue (Crawford
and deSmidt, 1922).

Habitat. — On reefs or among rocks, among
growths of sponges or other objects which afford
protection or places of concealment; low-tide
mark to depths of about 50 fathoms. Experimen-
tally, lobsters at Bermuda have withstood depths
of 250 fathoms (Creaser and Travis, 1950).

Type locality. — Erroneously given as East In-
dies ("des Grandes-Indies").

Known range. — North Carolina through Gulf
of Mexico and West Indies to Rio de Janeiro,
Brazil; Bermuda.

Remarks. — A number of papers have been pub-
lished concerning the general ecology of Panu-
lirus argus. Only a summary of this work can be
given here. The most comprehensive single, gen-
eral treatment is that of Crawford and deSmidt
(1922) for the species in Florida, but substantial
additions to this work have been given by Dawson
(1949, 1954), Dawson and Idyll (1951), Lewis
(1951), Lewis, Moore, and Babis (1952), Mar-
shal] (1948), and Smith (1951). Mattox (1952)
gave biological notes on the species in Puerto
Rico, and Creaser (1950, 1952), Creaser and
Travis (1950), and Sutcliffe (1952, 1953, 1957)
discussed the species in Bermuda.

North Carolina must be regarded as the ex-
treme northern edge of the range o'f this species,
and, indeed, concentrations of the species large
enough to be exploited commercially occur only
in southern Florida, the West Indies southeast to
Puerto Rico, and at Bermuda. A large population
may exist in deep water in the northern Gulf of
Mexico (Moore, 1962). Differences in growth rate
and breeding habits may exist among these areas.

PanuliruA argus grows to a large size. In its
first year of life it reaches a length of about 2
inches (measurements of this species usually
given in inches in U.S.A.) and, though growth in
the young individuals is more rapid than in older
animals, increments in length after that time are

FISH AND WILDLIFE SERVICE

about an inch a year. Adults of 16-inch length
are approximately 16 years of age, the males at-
taining somewhat greater lengths than females.

After juvenile stages are past, molts average
about 2i times per year, occurring most fre-
quently from March to July and from December
to February, at least in the Florida area. Among
captive animals, molts without growth can occur.
About 12 days elapse from the first sign of molt-
ing until the new exoskeleton is hard enough to
resist denting, though hardening of the new shell
is not complete until the 28th day. Travis ( 195-1,
1955a, 1955b, 1957) gave an exhaustive study of
the molting process among spiny lobsters near the
age of sexual maturity. This work is beyond the
scope of the present summary, but her findings
show that molting among captive adolescent ani-
mals is largely confined to the warmer months at
Bermuda and is more frequent than among Flor-
ida specimens. Other evidence shows that growth
of the young is more rapid in Bermuda than in
Florida, and that sexual maturity is reached
sooner.

The mating season in Florida is principally
from Mai'ch through July. Sexual maturity is
reached in females as small as 6 inches long, but
ovigerous females under 8 inches in length are
rare. Mating pairs are judged to be about the
same age, and mating usually occurs in the hard-
shelled stage. At the time of mating the male
places a waxy spermatophore on the thoracic
sternum of the female. Prior to spawning, the
female scratches the surface of this packet with
the chelate fifth legs. The actual egg laying is
accomplished in about one-half hour, during
which the female lies partially on her back form-
ing a trough of the underside of her abdomen
with the aid of the exopods of the pleopods. Eggs
extruded from the oviducts pass backward from
the bases of the third legs over the spermatophore
and become attached to the endopods of the last
three pairs of pleopods. After spawning, the
spermatophore appears eroded as if enzymatic
action had partially destroyed it. The egsrs hatch
in about 1 month. A second mating and egg lay-
ing may ocur about a week after the hatch of the
first batch and at this time the ovary is spent and
the spermatophore almost completely eroded
away. Molting of females during this season oc-
curs only after spawning.

The spawning season in Florida is principally
from March through June, and mostly in April.
However, a few ovigerous females occur as late
as October (December in the Bahamas). In
Puerto Rico, the spawning season may be more
extended than in Florida, for 22 percent of fe-
males in the commercial catch in Puerto Rico are
ovigerous in September and 18 percent in Octo-
ber.

Direct evidence from the studies in Bermuda
shows that females may lay eggs twice in a season.
The number of eggs laid depends on the size of
the individual, and the second brood is smaller
than the first. Estimates show that a 9-inch fe-
male can lay 500,000 eggs, a 12-inch female 1,118,-
656, a 15-inch female 2,566,916. A second laying
by a 13-inch female consisted of 1,008,788 eggs.
Thus, it is estimated that a 15-inch female might
lay 4 million eggs a season.

In Bermuda and elsewhere, there is apparently
a movement of females from shallow to intermedi-
ate depths and from deeper water to these depths
for spawning. Aside from these movements, there
is evidence in Bermuda that the lobsters exhibit
considerable homing tendencies, often moving as
much as 5 miles against strong tides to return to
the place of original capture. Adults tagged in
Florida, on the other hand, have moved as much
as 100 miles in 100 days (Smith, 1954), but such
movement is probably exceptional.

The larva of the spiny lobster is a flattened,
leaf-shaped, planktonic organism which, before its
identity was known, was given the name phyllo-
soma. Development of the phyllosoma larvae of
P. argus has been studied off Florida and at other
points in the Atlantic Ocean from the West In-
dies to the southeastern coast of the United States
and north of Bermuda. Bigelow and Sears (1939)
found phyllosoma larvae (P. argus?) off Chinco-
teague Bay in July, 1929. Eleven stages have been
described from plankton. In Florida, the bulk of
freshly hatched larvae appear between June and
August, the last stages being taken in December
and January. The first postlarval, or puerulus,
stages appear in inshore waters from January to
March. Thus, larval development is judged to
require 6 months, and during that time the larvae
may be swept hundreds of miles from the spawn-
ing place. (Feliciano (1956) described a prenau-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

pliosoma stage which may at times be freed in the
water but this has yet to be confirmed.) The
puerulus is shaped like a miniature adult, but is
about 17 mm. long, colorless, and has a soft exo-
skeleton. It is nonplanktonic and settles in shal-
low water. Ten postlarval stages have been dis-
tinguished. Stages one through three avoid light,
hut later stages show no such reactions. At the
end of the first year, at the eleventh postlarval
stage, the young are approximately 2 inches long.

Aside from reactions of the very young post-
larvae to light, Hess (1940) showed that freshly
molted adults are sensitive to light in many re-
gions of their bodies, but as soon as the body is
again sclerotized no such reactions are apparent,
Sutcliffe (1956) demonstrated that in clear, shal-
low water lobsters sought cover in bright moon-
light. He concluded that movements attributed
to tidal responses were actually responses to light.

Stridulation by spiny lobsters (Palinuridae)
has been described by a number of workers
(Moulton, 1957) and in P. argus it is produced
primarily by a toothed ridge medial to the bases
of the antennae and extending anteriorly from be-
neath each eye. A corrugated membrane at the
base of each antenna is played against this ridge,
producing sound when the membrane is moved
proximally. Two types of sound are produced, a
slow rattle normally produced by animals in small
groups, and a rasp which accompanies defensive
behavior. A squeaking sound is also produced in
an unknown manner, by vibration of the body,
when a specimen is held in the hand of an ob-
server. The effect of these sounds on other lobsters
or marine life is unknown.

Pearse (1932a) determined the freezing point of
P. argus blood at Tortugas (range —1.86° to
-2.39° C).

Family Scyllaridae. Spanish lobsters

Carapace depressed; exoskeleton thick, hard,
sculptured or tuberculate; orbits excavated in
margins of dorsal surface. Antennae short and
broad with flat scalelike, stiff articles. Mandibles
with a one-jointed palp. Leps simple except
minutely chelate fifth pair in female.

The fossil record for (lie family Scyllaridae
extends back to the lower Eocene of the Gulf
Coast in North America (Rathlmn, 19."..')).

KEY TO GENERA AND SPECIES IN THE CAROLINAS

( Adapted in part from manuscript key by
F. A. Chace, Jr.)

a. Exognath of outer maxillipeds without a flagellum ;
terminal article of antennae with edge cut into deep

Idbes distally Scyllarus (p. 94).

b. Prominences on carapace blunt ; second article of
antennular peduncles dorsally flattened ; distal ar-
ticles of antennae meeting, or nearly meeting, in
midline ; first four abdominal tergites obscurely
notched posteriorly in midline ; pleura of fourth
abdominal segment rounded laterally,
c. Pregastric tooth of carapace broadly rounded ; two,
seldom three, distinct parallel grooves between pos-
terior marginal groove and posterior margin of
carapace ; first to fourth abdominal segments with
notch in posterior margin very shallow ; fourth
abdominal segment not elevated in midline

t-hncri (p. 95).
ce. Pregastric tooth almost always bilobed, incised ;
almost always a single distinct groove between
posterior marginal groove and posterior margin of
carapace ; first to fourth abdominal segments
showing a deep, narrow, median notch in posterior
margin ; fourth abdominal segment elevated, more

or less ridgelike in midline amcricanns (p. 96).

Mi. One gastric and all lateral prominences on carapace
sharp : second article of antennular peduncles cylin-
drical ; distal articles of antennae not nearly meeting
in midline : first four abdominal tergites deeply and
acutely notched posteriorly in midline; pleura of
fourth abdominal segment sharply rectangular or

acute laterally nciirctits (p. 97).

aa. Exognath of outer maxillipeds with a flagellum ;
terminal article of antennae with edge nearly smootti
or crenulate distally Scyllarides nodifer (p. 98).

Genus Scyllarus Fabricius, 1775

Fabricius, 1775, p. 413.

Recognition characters. — Carapace flattened,
width at anterolateral corners equal to or slightly
greater than length in midline; middorsal ridge
and an oblique ridge on each side prominent. An-
tennules with first articles broad, flattened, and
immovable, second article much narrower and
elongate; third and fourth articles slender; fla-
<iella short; abdomen, including telson, much
longer (nearly twice) than carapace; pleura of
first segment incised in center of lower edge,
second broad and pointed distally. Anterior pleo-
pods of male witli both rami slender, flattened,
hairy on outer border; remainder with exopods
small and lamellate, endopods rudimentary. An-
terior pleopods of female with both rami broad
and flattened; exopods of remainder lamellate.

FISH AND WILDLIFE SERVICE

endopods slender and with long silky hairs. Legs
stout, extending beyond carapace; first legs stout-
est, remainder progressively more slender; second
pair longest; dactyls of first pair somewhat ser-
rate on lower border, remainder simple ; fifth legs
of females subchelate. Third maxillipeds stout,
basal articles prismatic.

Scyllarus chacei Holthius

Figure 74

Scyllarus americanus: Hay and Shore, 1918, p. 389, pi. 28,
fig. 2.— Bouvier, 1925 (In part), pp. 448-450, pi. .7, fig. 3. —
Boone, 1930, p. 84, pi. 23, fig. A. Schmitt, 1935a (in part), p.
174, fig. 39.— Holthuis, 1959, p. 126.

Scyllarus chacei Holthuis, 1960b, p. 152.

Recognition characters. — Carapace with sur-
face squamose in part dorsally, lightly squamose
below lateral borders, with feathered setae (some
darkened) between squames; middorsal ridge
with anterior (pregastric) eminence large,
rounded, gastric eminence higher, upturned, car-
diac eminence somewhat smaller than pregastric ;
two coalesced spines over each orbit large and
somewhat separated from ridges over branchial
areas. Rostrum short, rounded, sides nearly paral-
lel. Anterior border of carapace emarginate. Or-
bits deeply excavated with a broad anterior notch,
a blunt tooth on proximal (fixed) antennal arti-
cle in center of notch. Anterolateral corners of
carapace spiniform, lateral borders roughened
with squames; a rather deep notch behind orbit
and another one farther back; area between pos-
terior marginal groove and posterior margin of
carapace nearly smooth but traversed by two, sel-
dom three, distinct parallel grooves.

Second antennular article elongate, flattened
above, anterior margin obliquely truncate. Anten-
nae spatulate, somewhat punctate; distal article
with irregularly rounded anterior border cut into
seven elongate, somewhat separated, lobes with
rounded ends, edges ciliated; medial two lobes
shortest and sharpest, lateral lobe obliquely trun-
cate and broadest; penultimate article short, bi-
lobed in dorsal view; proximal movable article
cordate, a prominent ridge throughout length to
spiniform tip, a less conspicuous and irregularly
shaped medial ridge, edges spinose.

Second, third, and fourth abdominal tergites
(and to some extent first) with arborescent fur-
rows running inward and forward toward mid-
line; first to fourth segments with median notch
in posterior margin very shallow, fourth segment

Figure 74. — Scyllarus chacei Holthuis. Male in dorsal
view, approximately X 2. Bob Simpson photo.

not elevated in midline. Third to fifth pleura
rounded distally, sixth with a rounded antero-
lateral lobe. Sternum triangular, broad at base,
smooth with furrows ciliated; male with slight
midventral elevation on fifth plate, elevation less
evident in female.

Measurements. — Length of carapace, 19 mm.;
length of abdomen 35 mm.

Habitat. — Nine to 100 fathoms.

Type locality. — North-northwest mouth of
Marowijne River, about 20 miles off coast of Suri-
nam.

Knoion range. — Off Cape Lookout, N.C.,
through Gulf of Mexico, West Indies, and Carib-
bean Sea to off Cape Sao Roque, Brazil.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Remarks. — Ovigerous females have been taken
off Florida in March, South Carolina in July,
Surinam in August and September, and northeast
Brazil in November.

Scyllarus americanus (Smith)

Figure 75

Arctus americanus Smith, 1869b, p. 119.

Scyllarus americanus: Bouvier, 1925 (in part),, pp. 448-450. —
Holthuis, 1960b, p. 152 (restr.).

Recognition characters. — Carapace with sur-
face squamose in part dorsally, a little squamose
below lateral borders posteriorly, lightly tuber-
culate toward epistome, with feathered setae
(some darkened) between squames; middorsal
ridge with anterior (pregastric) eminence large,
bilobed anteriorly, gastric eminence sharper and
more elevated, cardiac eminence not so sharp, bi-

Figuw 7.",. Scyllarus americanus i Smith). Ovigerous
female in dorsal view, approximately x 1.5. Bob Simp-
son photo.

lobed ; two coalesced blunt spines over each orbit
large and somewhat separated from ridges over
branchial areas. Rostrum short, rounded at tip,
a blunt keellike middorsal tubercle above. Ante-
rior border of carapace emarginate. Orbits deeply
excavated, margins broad, with a broad anterior
notch; a blunt tooth on proximal (fixed) antennal
article in center of notch. Anterolateral corners of
carapace spiniform, lateral borders roughened
with squames; a rather deep notch behind orbit
and another one farther back. Area between pos-
terior marginal groove and posterior margin of
carapace faintly squamose and traversed almost
always by a single distinct groove.

Second antennular article elongate, flattened
above, anterior margin obliquely truncate. An-
tennae spatulate, somewhat punctate, surface
variably covered with feathered setae; distal arti-
cle with irregularly rounded anterior border cut
into six somewhat separated lobes, edges ciliated,
medial lobe short, spiniform, next much larger
and less pointed, following three about equal in
length, tips rounded, lateral lobe about twice
width of intermediate lobes; penultimate article
short, bilobed in dorsal view; proximal movable
article triangular in outline, edges spinose, two
lateral spines larger than four variably sized
medial spines, a prominent ridge running to
apical spine nearly dividing article in half. ,

Second, third, and fourth tergites of abdomen
(and to some extent first) with arborescent fur-
rows running inward and forward toward mid-
line. First to fourth segments with median notch
in posterior margin fairly deep and narrow;
fourth segment elevated, more or less ridgelike
in midline. Third to fifth pleura rounded distally,
sixth with a narrowly rounded anterolateral lobe.
Sternum triangular, broad at base; smooth witli
furrows ciliated; male with a low tubercle in
center of fifth sternite, female similar.

Measurements. — Ovigerous female: length of
carapace, 25 mm., width, 29 mm.; length of
abdomen, 45 mm.

Habitat. — Surface to 19 fathoms, usually 3 to
12 fathoms.
Type locality. — Edgmont Key, Fla.
Known range.— OR Bogue Inlet, N.C., to south-
ern Florida; Campeche Banks off Mexico.

Remarks. — Ovigerous females have been taken
in southern Florida in September.

FISH AND WILDLIFE SERVICE

Scyltarus nearctus Holthuis

Figure 76

Scyllarus nearctus Holthuis, 1960b, p. 151.

Scyllarus arctus paradoxus: Rathbun, 1900b (in part), p. 309.

Recognition characters. — Carapace with sur-
face squamose in part dorsally, but only on or
near ridges and sides, smooth below except a
sinuous submarginal row of tubercles and a
lightly granulate area posteriorly, densely ciliate
above between squames and on smooth areas.
Rostrum short and acute; pregastric tooth above
it about same size, gastric tooth larger, acute, all
three of these directed forward. Cardiac eminence
blunt, bilobed at apex. Gastric tooth and cardiac
eminence with squames at base, rostrum and
pregastric tooth in smooth area. Lateral ridges
ending anteriorly in a forwardly directed spine.
Front emarginate with a small projection about
halfway between rostrum and orbit. Orbits
deeply excavated, upper border composed of two
spines coalesced at base, lower border an inflated
ridge more or less interrupted by two subequal
spines at anterolateral corner; anterior notch
partially occupied in middle by a large serrulate
tooth on first (fused) antennular article and an-
other eminence forming articulation of second
antennal article. Anterolateral corners of cara-
pace drawn out to a strong spine, lateral border
with a notch behind eye and another less definite
notch behind anterior end of branchial ridge.
Posterior margin of carapace with a sharp but
broadly opened notch in midline; area between
posterior marginal groove and posterior margin
of carapace traversed by two rows of squames.

Anterior border of first antennular article with
low teeth or irregularities; second article cylin-
drical with a flattened, rounded distal projection ;
succeeding articles slender, flagella short. Anten-
nae spatulate, fairly smooth, ciliated, edges
densely covered with longer feathered setae ; distal
article semielliptical in outline, edge broken into
six well-separated lobes with narrowly rounded
tips, inner lobe smallest, outer broadest and sub-
truncate, a suggestion of a seventh lobe medially;
penultimate article short, irregularly spined and
lobed; first movable article roughly triangular
with apex formed by a strong spine, two spines
on outer border and three spines on inner border,
apical spine and first two inner spines with small
spurs on medial borders, third spine at medio-

posterior border smaller, a definite ridge running
across article from articulation to apex.

Second to fifth abdominal segments (and to
some extent first) with arborescent furrows run-
ning inward and forward toward midline. First
to fourth segments with median notch in posterior
margin deep and narrow. Third and fourth with
distal edge of pleura rounded anteroventrally,
angled at posteroventral corner; fifth broadly
rounded distally; sixth with anteroventral lobe
broad and rounded. Telson with four flattened
spines at distal edge of hard portion. Each ramus
of uropods with a spine at same level on outer
margin.

Figure 76. — ScijHarm nearctus Holthuis. Male paratype
in dorsal view, approximately X 1.5. Bob Simpson
photo.

MARINE DECAPOD CRUSTACEANS OF THE CAROLJNAS

Sternum triangular, narrower in males than in
females, smooth, a little pubescent in grooves.
Male with a strong, shelf like protuberance on
sternite between last pair of legs, and with a
strong sharply ridged shoulder extending over
genital pore. Female with a low eminence on
sternite between last pair of legs.

Measurements. — Ovigerous female: length of
carapace, 24 mm., width, 26 mm.; abdomen,
length, approximately 50 mm.

Habitat.— Thirty to 100 fathoms.

Type locality. — South of Dry Tortugas, Fla.

Known range. — Off Cape Hatteras, N.C.,
through Gulf of Mexico and West Indies to State
of Sao Paulo, Brazil.

Remarks. — Ovigerous females have been taken
off North Carolina in June.

Genus Scyllarides Gill, 1898

Gill, 1898, p. 99. — Verill, 1922, p. 18. (rev.). — Hemming,
1958b, p. 94.

Scyllarides nodifer (Stimpson)

Figure 77

Scyllarus nodifer Stimpson, 1866, p. 48. — Stimpson, 1871b,
p. 123.

Scyllarides americanus Verrill. 1922, p. 24, pis. 5-6.
Scyllarides nodifer: Holthuis, 1960b, p. 153.

Recognition characters. — Carapace longer than
wide, subtruncate in front, coarsely and unevenly
granulate, granules elevated, not crowded, each
surrounded by more or less complete circle of
stiff hail's; anterolateral corners forming nearly a
right angle terminating in an obtuse tooth; cervi-
cal notch and groove well marked with numerous
denticles on margin in front of and behind notch ;
posterior transverse groove deep and conspicuous ;
gastric area with a large, broad-based, prominent
median ridge divided into a smaller anterior and
larger posterior part, each portion ending in an
anterior, large, conical, obtuse or bilobed tubercle
with other similar but smaller tubercles and coarse
granules around and behind apex; cardiac region
with a prominent hut less elevated area with
larger tubercles than on adjacent surface; a
similar ridge on each branchial area. Orbits
large, with prominent, thick borders, anterior
notch wide and deep.

Antennae with distal article broader than long,
edges broadly and evenly rounded, minutcU
lobulate and crenulate, fringed with short, close
haii-s; exposed portion forming a half oval, upper

side covered with small, rough granules and small
pits bearing tufts of short hairs in large adults,
smoother in small individuals. Penultimate mov-
able article showing two lobes beneath. Second
movable article distinctly wider than long,
broader than distal article; distal lobe terminat-
ing in nearly right angled point in large adults,
armed with a spine in smaller specimens; edges
dentate with many small teeth and some larger
ones, a larger stout tooth near inner curve of
inner margin; inner lateral lobe stout, thick, en-
larged toward end; inner edges of these lobes of
both antennae separated by a space about equal
to orbit of eye. First movable article irregularly
four-lobed above; small outer lateral lobe with
about three denticles; median or distal lobe
swollen and coarsely granular; inner lobe ob-
liquely oblong with inner edge truncate and
denticulate; prefrontal or rostral lobe a little
broader than long, widest distally, swollen
laterally, with concave sides and a median groove.

Outer maxillipeds large, basal articles stout.
Legs projecting beyond carapace; first pair
stouter than others, propodus considerably swol-
len, dactyl stout ; fifth pair with propodus most
slender; merus and carpus of all pairs, except
carpus of first, with a finely serrulate carina end-
ing in a sharp distal tooth; carpi, except first,
with a lateral carina ending in a distal tooth; meri
of last four legs with a ventrolateral carina end-
ing in a sharp spine distally (carina sharpest on
legs three and four) and each with a blunter
medial spine distally.

Underside of bases of legs and sternum roughly
sculptured, one larger acute or pyramidal eleva-
tion on sternum opposite base of each leg.

Abdomen strongly sculptured, elevated areas
coarsely granulated and hairy, much like cara-
pace. Second to fourth segments with a median,
elevated, obtuse ridge, covered with large gran-
ules; fifth segment with slight ridge. Pleura
large, angular; that of second segment largest,
subacute, both edges with dentations about as
large as adjacent granules; those of third to
sixth segments more minutely dentate on posterior
border, nearly smooth or minutely crenulate on
anterior border. Telson broader than long, sub-
t ruinate distally; posterolateral angles broadly
rounded: granulated and hairy proximally,
covered with numerous forked ridjjes and grooves

FISH AND WILDLIFE SERVICE

Figure 77. — Scyllarides nodifer (Stimpson). Female in dorsal view, approximately X 0.5. Bob Simpson photo.

distally becoming fine near edge. Uropods broad,
sculptured as telson. Sternum of second segment
in males bearing a sharply raised, serrate, heavily
sclerotized ridge.

Measurements. -^Length of carapace: female,
127 mm. Larger specimens have been observed
but not measured.

Variations. — Smaller specimens are smoother
than adults.

Color. — Body covered with irregular small
brown spots on a grayish brown to yellowish
background ; many orange-red tubercles on edges,
across ridge near rear edge of carapace, base and
edges of antennal lobes; darker red spots at sides
of gastric region, on anterior lobes of carapace
and at middle of first abdominal segment ; under-
pays yellow with darker yellow and brown spots;
legs banded with red and purple; flagella of
antennules purple.

Habitat. — Mud, shell, coral, and sandy bottoms;
16 to 40 fathoms.

Type locality. — Florida Keys.

Known range. — Bermuda ; Cape Lookout, N.C.,
to Cuba; off Pensacola, Fla.

Remarks. — Little is known of these lobsters.
They are sometimes used for food or bait.

Superfamily Thalassinidea

Exoskeleton often more or less membranous.
Carapace compressed. Last articles of second to
fourth legs not curved and flattened. Abdomen
large, symmetrical, extended, sometimes with
well-developed pleura; appendages of sixth seg-
ment usually adapted for swimming.

Family Callianassidae

Body shrimplike. Carapace with a "linea
thalassinicay Antennal peduncle five-jointed;

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

antennal scale vestigial, no antennal acicle. First
pair of legs unequal or subequal, perfectly or
imperfectly chelate; third and fourth pairs sim-
ple; others variable. Abdomen extended; pleura
small or absent; sixth abdominal appendages with
no sutures; tail fan well developed; broad ap-
pendages on third to sixth abdominal segments
(after Hay and Shore, 1918; Schmitt, 1921).

KEY TO GENERA AND SPECIES IN THE CAROLINAS

a. Rostruni small ; first two pairs of pleopods different
from following three pairs ; chelipeds dissimilar and

unequal Callianassa (p. 100).

b. Uropodal endopods narrow, about 4 times longer

than broad C. major (p. 100).

bb. Uropodal endopods not much longer than broad

C. atlantica (p. 102).
aa. Rostrum large; second pair of pleopods like follow-
ing three pairs ; chelipeds alike and subsequal

Upoycbia afflnis (p. 103).

Genus Callianassa [Leach, 1814]

Leach, [1814], p. 400.— Hemming, 1958b, p. 142u

The genus Callianassa has a fossil record ex-
tending back to the Jurassic (Rathbun, 1926).

Subgenus Callichirus Stimpson, 1866

Stlmpeon, 18(66, p. 47.

Callianassa (Callichirus) major Say

Figure 78

Callianassa major Say, 1818, p. 238. — Schmitt, 1935b (rev.).
Callichirus major: Hay and Shore, 1918, p. 407, pi. 29, fig. 10. —
de Man, 1928, p. 30 (rev.).

Recognition characters. — Integument more or
less thin and membranous; chelipeds and an oval
plate covering anterior three-fourths of carapace,
being most hardened portions. Rostrum minute,
somewhat obtuse; a similar projecting lobe at
each side on margin of front. Cornea of eyes
minute, situated at about middle of outer margin
of flattened and pointed ocular peduncles. Anten-
nular peduncles about two-thirds as long as cara-
pace, si out, densely hairy below: each with two
flagella about as long as distal article of peduncle.
Antenna slender, longer than carapace, peduncle
bent between second and third article.

( ihelipeds unequal, showing sexual dimorphism.
Males with major cheliped rather large; granular
along proximal lower edge of carpus, lower edge
of merus and over entire ischium; propodus and
carpus about equal in length, twice as broad as
merus and more than three times as broad as

Figuke 78. — Callianassa (Callichirus) major Say. A,
major cheliped of female, approximately X 2; B,
minor cheliped of male, approximately X 2 ; C, major
cheliped of male, approximately life size ; D, right
uropod and portion of telson in dorsal view, ap-
proximately X 3 (after Lunz, 1937b).

ischium; merus with a strong tooth on lower
proximal border; fingers strong, dactyl hooking
over outside fixed finger, a strong tooth near
base. Major cheliped of female weaker, not
granular; propodus and carpus proportionately
shorter than in male; merus without tooth on
lower proximal border; dactyl hooking over in-
side fixed finger. Minor cheliped of male and
female similar, small; fingers weak, meeting only
at tips; carpus as long as hand and somewhat
wider. Chelipeds and first three pairs of walking
legs much compressed ; margins of distal articles
on first two pairs especially sharp; first walking
legs chelate, with long cilia on lower margin ;
second legs with propodus transverse, it and small
triangular dactyl densely ciliate; third and
fourth walking legs with last two articles hairy,
last legs subcylindrical.

Abdomen long, gradually widening from an-
terior end to third segment, then narrowing

ion

FISH AND WILDLIFE SERVICE

slightly to sixth; sixth segment deeply grooved
above. First two pleopods small and slender in
male, larger and definitely biramous in female;
remaining pleopods broad and overlapping. Uro-
pods with exopod broad, rounded distally; distal
half covered with mat of dense short hair becom-
ing longer on border; endopod narrow, obliquely
truncate, hairy at tip only. Telson with an in-
flated area on each side giving notched or fissured
appearance.

Measurements. — Length of body: males, 95
mm. ; females, 92 mm. ; ovigerous females, 80 mm.
(Lunz, 1937b).

Color. — Transparent gray except for porcelain
white chelipeds and hardened portion of carapace
(Lunz, 1937b).

Habitat. — Burrows in sandy shores on or near
open ocean; intertidal zone to 1 fathom.

Type locality. — Coasts of Southern States and
east Florida [St. Johns River].

Known range. — Beaufort Inlet, N.C., to eastern
Florida; Grand Terre Island to Timbalier Island,
La.

Remarks. — For many years this species was
known only from a single specimen from Beau-
fort, N.C., and early descriptions of specimens
from South Carolina and Florida. The rarity of
occurrence in collections is due to the secretive
burrowing habits of the form, for it easily escapes
detection of the casual observer using conven-
tional methods of collection. (Collections can be
made by removing the mouth of the burrow,
dropping pebbles or debris down the hole, wait-
ing for the animal to appear at the exposed sur-
face, then jabbing a shovel into the sand below
the animal, thus cutting off escape into the bur-
row.) Such habits no doubt also enhance chances
for fossilization, for the genus is abundant in the
Cretaceous and Eocene of the Gulf coastal plain,
and somewhat less abundant in later deposits
down to the present time (Rathbun, 1935).

Lunz (1937b) was the first recent student to
determine the habitat and abundance of the
species in South Carolina and his studies were
closely followed by those, of Willis (1942) in
Louisiana, and Pearse, Huram, and Wharton
(1942), and Pold (1946) in North Carolina.

The animal lives in deep burrows on sandy
beaches that either face the open ocean or are
close to it. In Louisiana, the burrows occupy a

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
7'63-04'9 O— 65 8

band from the intertidal zone to a distance of over
100 feet from shore in 5 to 6 feet of water. The
tubular burrows, usually vertical to the surface,
are divided into three portions. The mouth, about
5 mm. in diameter, opens into the upper portion,
5 to 20 cm. long and 5 to 8 mm. in diameter. From
this the middle portion, 10 to 15 cm. long and
often angled, widens gradually to approximately
20 mm. The third portion, 20 mm. wide, is the
longest. An approximate average depth of the
whole burrow is 146 cm. with variations from 60
to over 210 cm. Branches are common and arise
most often from the middle portion. Character-
istically, the burrows are lined with a brown
material, thinnest in the upper portion and
thickest (3 to 7 mm.) in the lower portion. The
burrows often end in an enlarged pocket lined
witli crushed shell, and in some the lined tube
extends below the pocket.

Burrow mouths are often surrounded by fecal
pellets of C. major, which resist rapid disintegra-
tion in water. On some South Carolina beaches,
such pellets were washed together in patches
measuring up to 10 by 50 feet and piled to a
depth of 0.25 inch. Mouths of burrows are not
uniformly scattered but tend to be clumped in
patches or tracts, often as dense as three or four
openings per square foot. Chimneylike structures
at the mouths of burrows noted by Say have not
been confirmed, but a small raised ridge of sand
often surrounds burrow mouths. Other mouths
are not marked or may be located in a depression.

In captivity, the animals burrow in sand head-
first with the anterior appendages until a shallow
pit is constructed, then the animals reverse them-
selves and continue to burrow tailfirst. Though
the shrimp do at times emerge voluntarily from
their burrows, such behavior is probably infre-
quent and may be confined to the breeding season
(Lunz, 1937b). The species is well fitted for a
fossorial life by virtue of the slender, elongate
body, thin exoskeleton, and flattened hairy ap-
pendages adapted for burrowing, carrying sand,
sifting food, and pumping water for feeding and
respiratory currents. Examination of gut con-
tents has shown an amorphous mass containing
sand grains, diatoms and other algae, and many
bacteria.

Ovigerous females have been reported from
South Carolina in July and August, and they are

101

known from North Carolina in June and July.
Pohl (1946) counted 8,170 attached eggs on one
female. Pinnixa cristata has been found as a
commensal in the burrows.

Callianassa (Callichirus) atlantica Rathbun
Figure 79

Callianassa stimpsoni Smith, 1873c, p. 549, pi. 2, fig. 8. — Hay
and Shore, 1918, p. 406, pi. 29, fig. 5.

Callianassa atlantica Rathbun, 1926, p. 107. — de Man, 1928,
p. 37 (rev.). — Rathbun, 1935, p. 104. — Schmitt, 1935b, p. 4.

Recognition characters. — Integument smooth,
shining, thin, almost membranous. Carapace
about one-third length of abdomen, thin but with
oval thickened plate on gastric region. Rostrum
small, acute, flanked by a small triangular promi-
nence at each side on frontal margin. Eyestalks
small, flat, contiguous medially; pointed tips
slender, curved outward and upward; cornea
small, situated on outer border. Antemiular
peduncles about one-half length of carapace;
flagella about as long as distal article of peduncle,
densely hairy below. Antenna slender, longer than
carapace; peduncle much shorter than that of
antennules, bent between second and third articles.
Third maxilliped operculiform; dactyl slender.

Chelipeds unequal, showing sexual dimorphism.
Larger cheliped of male with fingers about equal
in length, hairy, tips incurved; cutting edge of
dactyl with a long, low, truncate tooth at base,
smaller teeth distally; immovable finger with
small teeth; palm hairy below, upper border
ridged along proximal two-thirds ; carpus as wide
as but shorter than palm, upper and lower border
ridged; merus articulating with carpus by ex-
treme upper angle, a prominent, denticulate tooth
on lower border proximally; ischium with six or
seven subacute teeth on lower border. Smaller
cheliped of male with fingers a little longer than
palm ; carpus four times as long as broad distally,
a little longer than palm, half again as long as
merus; merus twice as broad as long. Larger
cheliped of female, less toothed than in male;
smaller cheliped as in male.

Abdomen with third to fifth segments of about
equal width, each with a small patch of fine hairs
on posterolateral angle; sixth segment broader
than long. Male with no pleopods on first and
second segments. Female with uniramous pleo
pods <>ii first segment : slender, biramous pleopods
on second segment ; remainder well developed in

Figure 79. — Callianassa {Callichirus) atlantica Rath-
bun. A, frontal region in dorsal view ; B, frontal
region, eyestalks and antennules in dorsal view ; C,
sixth abdominal segment, right uropod and telson in
dorsal view (after de Man. 1928).

both sexes. Telson nearly as long as broad; sub-
truncate distally, corners rounded. Exopods of
uropods broader than endopods, both rami
densely fringed with hairs distally.

Measurements. — Length of l>ody: male, 59
mm. ; female, 68 mm.

Habitat. — Muddy shores and bottoms in shal-
low water (Sumner, Osburn, and Cole, 1913a, b) :
shoreline to approximately 21 fathoms.

Type locality. — "Qui- species ranges from the
(•(last of the Southern [United] States north to
Long Island Sound" (Smith, 1S7:'.c).

102

FISH AND WILDLIFE SERVICE

Known range. — Bass River, Nova Scotia, to
South Carolina; Franklin County, Fla.

Remarks.— Both de Man (1928) and Schmitt
(1935b) pointed out that Rathbun renamed this
species because the name stimpsoni was preoccu-
pied by a fossil species of Gallianassa named by
Gabb in 1864. Gallianassa atlantica itself has a fos-
sil record extending from a first appearance in the
upper Miocene of North Carolina and Virginia,
and a later occurrence in the Pleistocene of Mary-
land to the present (Rathbun, 1935).

Ovigerous females have been taken in Massa-
chusetts and South Carolina in July. Juveniles
4 mm. long have been collected on the surface in
September in Massachusetts (de Man, 1928). This
form is rarely taken in the Carolinas but has been
collected in areas ranging from salty estuaries to
offshore fishing banks.

Genus Upogebia [Leach, 1814]

Leach, [1814J, p. 400.— Hemming, 1958b, p. 143.

Upogebia affinis (Say)

Figure 80

Gebia affinis Say, 1818, p. 241.

Upogebia affinis: Hay and Shore, 1918, p. 408, pi. 29, fig. 9. —
Schmitt, 1935a, p. 196 (rev.).

Recognition characters. — Integument, except
dorsal part of carapace and of legs, more or less
membranous. Carapace about half as long as ab-
domen; cephalic portion about twice as long as
thoracic, nearly flat above, anteriorly rugose and
covered with short, rigid hairs. Rostrum large,
flanked on each side at base by a large spine,
spiny beneath in midline. A small upcurved spine
behind eye on anterior margin, and a minute
lateral spine behind cervical groove. Eyestalks
concealed, pubescent above; corneal surface small.
Antenna a little less than twice as long as cara-
pace.

Chelipeds stout, a fringe of long hairs below;
hands with an external, dentate ridge above, a
median row of acute spines and an internal line of
stiff hairs; immovable finger curved, movable
finger much longer, denticulate above at base, cut-
ting edges of both toothed near base; carpus
grooved on outer face with a row of small spines
and a strong marginal spine below, a row of small
teeth on inner margin, and six acute spines along
distal margin above; merus with a small spine
above and a row of spines beneath. First pair of

walking legs hairy at tips and along lower mar-
gin; merus with a strong spine at base. Remain-
ing legs hairy at tips.

Abdomen gradually increasing in width from
first to fourth segment, fifth narrower posteriorly,
sixth subquadrate; lateral portions of third and
fourth segments densely pubescent and all with
pleura marked off by an impressed line. Tail fan
densely hairy distally. Uropodal endopods trun-
cate and with a median rib and costate outer
border; exopods rounded distally and with two
ridges. Telson broad, subquadrate, with an im-
pressed median line.

Measurements. — Length of body: males, 61
mm. ; females, 63 mm.

Variations. — Schmitt (1935b) mentioned the
variability in spination of the lower border of the
rostrum and multiple spination or lack of spines
behind the cervical groove. Young specimens
often lack these spines.

Color. — Gray, blue, or yellowish gray dorsally,
tinged with light blue medially on tail fan and
on fifth segment of abdomen, interlaced with uni-
form light lines; an oblique blue spot on side of

Figure 80. — Upogebia affinis (Say). A, rostral re-
gion and eyes of semiadult female in dorsal view ;
B, rostral region of semiadult female in lateral
view; C, major chela (after de Man, 1927).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

103

carapace at base of antenna extending postero-
dorsally; underparts light (various authors).

Habitat. — Burrows on estuarine mud flats and
in shallow estuaries; intertidal to 15 fathoms.

Type locality. — Georgia.

Known range. — Wellfleet, Mass., to Rockport,
Tex. (Hedgpeth, 1950) ; through West Indies to
Maceio, Alagoas, Brazil (deMan, 1927).

Remarks. — A species of Upogebia is known
from the Eocene of Alabama (Rathbun, 1935).

Ecological notes on U. affinis in North Carolina
were reported by Pearse (1945). The species in-
habits muddy situations in estuaries where salini-
ties are fairly high. Its burrowing habits are
similar to those of Callianassa. Wass (1955)
found burrows prevalent in Florida where the
marine grass Halodule wnghtii stabilizes muddy
substrates. Burrows examined by Pearse were 30
to 50 cm. deep with openings about 30 cm. above
low-tide mark. They were often branched, con-
taining several individuals each in its own branch,
and showed one to eight small openings at the
surface. In communal burrows he often found
two or three ovigerous females and one or two
juveniles. Like the burrows of Callianassa, those
of U. affinis are narrowest in the upper portion.
Pearse concluded that the animals seldom leave
their confines.

In captivity, U. affinis made only feeble at-
tempts to burrow. In nature, however, the animals
are active and pump water vigorously from the
anterior to posterior end of the body by flapping
movements of the pleopods. Food is apparently
strained from the water by the hairy mouth parts
and walking legs, and probably consists largely of
organic materials swept in the water current.

Ovigerous females were studied in detail in
August, though Hay and Shore (1918) pointed
out that the breeding season lasts throughout the
summer, and juveniles have been collected in
Bogue Sound, N.C., in plankton tows from early
April to late October. Fish (1925) reported
larvae at Woods Hole from mid-July to the latter
part of October, but they were mosl abundant in
early August. A single female may produce about
1.0,000 eggs at a time. They are borne on the first
four pairs of pleopods. In captivity, more zoeae
wen- hatched at nighl than in daytime. Pearse
cited MacGinitie (1934) for evidence that /'. affi-
nis, like members of the related genus Callianassa,

may live several years, though there is no evidence
supporting this idea for the former.

Upogebia affinis is commonly parasitized in
North Carolina by the lx>pyrid, Pseudodione upo-
gebiae Hay. Pearse (1952a) described a parasitic
isopod, Phyllodurus robvstus, from a Florida
specimen.

Section Anomura

Abdomen well developed, either symmetrical
and flexed beneath thorax, exceptionally extended
in a straight line usually flexed on itself, or asym-
metrical, coiled and imperfectly armored, almost
always with biramous appendages on sixth seg-
ment. Carapace usually depressed, free from epi-
stome, traversed on either side in longitudinal or
obliquely longitudinal direction by distinct suture
(linea anomurica) more or less marking off side-
wall of carapace from dorsal and dorsolateral por-
tion. Last thoracic sternum free (or atrophied).
First pair of legs well developed and chelate;
second and third pairs well developed, not che-
late: fifth pair markedly different from third.

Superfamily Galatheidea

Carapace more or less depressed. Abdomen rela-
tively well developed, not closely folded beneath
cephalothorax, symmetrical, and with well-de-
veloped pleura, but to some extent not capable of
complete extension. Eye scales absent. Antennal
peduncle with third article indistinct. Last tho-
racic sternum distinct. Second to fourth legs with
dactyl not curved and flattened. Males with at
least a pair of sexual appendages.

Family Galatheidae

Carapace longer than wide, often ornamented
with transverse, ciliated lines. Rostrum distinct
and strongly pointed, projecting beyond eyes.
Antennular peduncle elongate. Antennae with
four- jointed peduncle. Chelipeds greatly elon-
gated, slender. First, second, and third walking
legs well developed; fourth leg feeble, reduced in
size. Abdomen bent upon itself but not folded
under thorax; males with a pair of sexually modi-
fied pleopods on segment two. a pair of uniramous
pleopods on segments three, four, and five; fe-
males with rudimentary pleopods on second ab-
dominal segment, fully developed pleopods on
three, four, and live.

104

FISH AND WILDLIFE SERVICE

KEY TO GENERA AND SPECIES IN THE CAROLINAS

a. Rostrum rather broad, margins toothed

Galathea rostrata (p. 105).

aa. Rostrum slender, toothless except for supraocular

teeth at extreme base Munida irrasa (p. 105).

Genus Galathea Fabricius, 1793

Fabrlcius, 17,93, p. 471.— Milne Edwards and Bouvier, 1897,
p. 13.— Hemming, 1958b, p. 143.

Galathea rostrata Milne Edwards

Figure 81

Galathea rostrata Milne Edwards, 1S80, p. 47. — Hay and Shore,
1918, p. 402. pi. 29, fig. 4 (rev.).— Chace, 1942, p. 30.

Recognition characters. — Carapace somewhat
flattened; transverse ciliated ridges prominent, at
least four continuous for entire width of cara-
pace; lateral margins with a number of acute
spines. Front prolonged into a broad, acute ros-
trum armed with four strong, anteriorly pointing
spines on each side. Third maxilliped with inner
margin of merus armed with three or four spines.

Chelipeds nearly twice as long as body, com-
paratively heavy; with rows of spines or spini-
form granules along margins and appressed,

Figure 81. — Galathea rostrata Milne Edwards. Animal
in dorsal view, walking legs of right side not shown, 3
mm. indicated.

squamiform, ciliated granules on surfaces; a few
larger spines on carpus and distal end of merus;
hand a little shorter than body; fingers gaping at
base.

Abdomen with transverse striae like those on
carapace but without spines.

Measurements. — Length of body : male, 18 mm.

Color. — Ground color off white, cream, and
light yellow; mottled with orange and reddish
orange especially on legs, less evident on body;
spines red or tipped with red ; a single small cir-
cular reddish spot in center of each branchial
region; a white band on propodi of walking legs;
distal half of lingers white (from specimen re-
cently preserved in formalin).

Habitat. — Ten to 50 fathoms; (rarely to 1,178
fathoms south of Block Island, R.I. ? ) .

Type locality. — Sixteen miles north of Jolbos
Islands [Yucatan Peninsula] at 14 fathoms.

Known range. — Off Cape Hatteras, N.C., to off
Mississippi River Delta, and Yucatan, Mexico;
(Rhode Island?).

Remarks. — Reports of this species are rare in
the literature and only a few specimens have been
taken off Beaufort, N.C.

Ovigerous females have been reported off west-
ern Florida in March and April (Milne EdwTards
and Bouvier, 1897, and U.S. National Museum
records).

Genus Munida Leach, 1820

Leach, 1820, p. 52. — Milne Edwards and Bouvier, 1897, p. 20
(rev.).

Munida irrasa Milne Edwards

Figure 82

Munida irrasa Milne Edwards, 1880, p. 49. — Hay and Shore,
1918, p. 402, pi. 28, fig. 8.— Chace, 1942, p. 46 (rev.).

Recognition characters. — Carapace narrowed
anteriorly, adorned with iridescent pubescence,
spiny. Rostral spine much longer than supraocu-
lar spines, latter not extending so far as cornea.
A row of 10 spines across gastric region in addi-
tion to 1 or 2 on each hepatic region, 2 to 4 on each
triangular area, and 1 to 4 on either side behind
cervical groove on inner portion of each branchial
region; anterolateral spine long, followed by 6
distinct lateral spines. Merus of third maxillipeds
with three spines on lower margin.

Chelipeds three or four times as long as cara-
pace, covered with squamiform, ciliated tubercles;

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

105

Figube 82.- — Munida irrasa Milne Ed-
wards. Animal in dorsal view (after
Milne Edwards and Bouvier, 1897).

fingers agape at base; merus with rows of spines
continued on carpus and hand. First pair of
walking legs reaching proximal end of hand.

Abdomen without spines.

Measurement*. — Length of carapace: males, 11
mm. ; females, 14 mm. ; smallest ovigerous female,
4 mm. (Chace, 1942).

Habitat.— Thirty to 260 fathoms.

Type locality. — Not designated with certainty.

Known ranf/e. — Off Cape Lookout, N.C. ;
Florida through AVest Indies to Grenada; Gulf
of Mexico to Colombia and Venezuela; "600 mi.
off St. I >avids, Bermuda."

Remarks. — Ovigerous females have been taken
off southeast Florida in July, and off North Caro-
lina in September. The rhizocephalans Cyphosac-
cus chacei and Boschmaia iminidicola were re-
ported from M. irrasa by Reinhard (1958).

Family Porcellanidae

General form crablike. Carapace well calcified,
depressed, regions usually not well defined; front
often prominent but never with rostrum greatly
projecting beyond eyes. Antennae inserted ex-
ternal to eyes, with three movable articles and a
flagellum. Basal articles of antennules broad.
Outer maxillipeds too large to be contained in
buccal cavity. Chelipeds moderately elongate,
usually broad and depressed. First, second, and
third walking legs well developed; last leg feeble,
reduced in size, inflexed and resting on carapace.
Abdomen broad, symmetrical, composed of seven
segments, bent under and held closely against
thorax ; males with a pair of pleopods on segment
two, sometimes rudimentary or absent, females
with a pair of pleopods on segments three, four,
and five, those on three sometimes reduced or ab-
sent. Telson composed of five or seven well-calci-
fied pieces (Haig, 1960).

KEY TO GENERA AND SPECIES IN THE CAROLINA

(Modified after Chace. 1942)
a. Form elongate, "hippalike" ; telson much longer than

broad Euoeramus praelongus (p. 109).

aa. Form less elongate ; telson usually broader than long,
never much longer than broad.

b. Lateral wall of carapace broken up into two or more
pieces, separated by membranous interspaces; front
triangular or transverse in dorsal view, never with
projecting teeth ; carapace subquadrate.
c. Carapace with numerous transverse tufts of setae;
chelipeds and legs hairy

Paohyoheles pilosus (p. 10S).
cc. Carapace relatively smooth, not hairy ; chelipeds
deeply ridged and eroded, not hairy

Pachychrh x rinniiiiuuia (p. 10s I .
bb. Lateral wall of carapace nearly always entire; if
not, front distinctly tridentate in dorsal view; cara-
pace not subquadrate.

c. Basal antennal article small, not joining margin
of carapace, so thai movable articles have free ac-
cess to orbit Petroliathes golathinus i p. 107).

CC. Basal antennal article strongly produced for-
ward and broadly in contact with margin of cara-
pace, movable portion far removed from orbit,
d. Dactyls of walking legs armed with from two
to four strong, fixed spines; carapace distinctly
broader than long Polyonyx gibbesi (p. 113).

106

FISH AND WILDLIFE SERVICE

dd. Dactyls of walking legs ending in a simple
spine usually with small, movable accessory spin-
ules on lower margin ; carapace longer than
broad.

e. Front strongly tridentate in dorsal view ; cara-
pace slightly longer than broad ; chelipeds not
grossly sculptured.

f. Cervical groove terminating anterolateral^
in shallow marginal indentation at edge of

carapace Porcellana sayana (p. 110).

ff. Cervical groove terminating anterolateral^
in a distinct longitudinal cleft at edge of

carapace Porcellana sigsbciana (p. 111).

ee. Front strongly trilobate in frontal view ;
carapace usually broader than long ; chelipeds
thick and grossly sculptured

Megalobrachium soriatum (p. 112).

Genus Petrolisthes Stimpson, 1858

Sttmpson, 1858, p. 240.— Halg, 1960, p. 21.

Petrolisthes galathinus (Bosc)

Figure 83

Porcellana galathina Bosc, 1801 (or 18021, p. 233, pi. 6, fig. 2.
Petrolisthes galathinus: Hay and Shore, 1918, p. 404, pi. 29,
fig. 1.— Haig, 1956, p. 22 (rev.).— 1960, p. 36.

Figure 83. — Petrolisthes galathinus (Bosc). Animal in
dorsal view, fifth leg only of left side shown, 5 mm.
indicated.

Recognition characters. — Carapace a little
longer than wide, covered with strong, transverse,
ciliated rugae, scarcely interrupted at grooves
separating well-marked regions; frontal region
granulate, metabranchial regions plicate. Front
produced into a broad, triangular, sinuous-sided
rostrum with a broad median groove usually
covered with short pubescence. Supraorbital
spine present, not distinct in large specimens;
postorbital angle produced into a small spine-
tipped tooth; epibranchial spine strong. Eyes
well developed. Antenna with first movable article
bearing an anteromedian, spine-tipped, lamellar
lobe; second and third articles lightly rugose.

Chelipeds large, covered with strong, ciliated
rugae continuing obliquely and almost unbroken
across carpus and hand, broken into series of
shorter rugae on fingers; merus with a strong
rugose lobe at inner distal angle; carpus about
twice as long as wide, anterior margin with four
to six strong serrate spines, a row of spines on
posterior margin ; hand broad, flattened, rugae on
outer margin spiniform in smaller specimens,
outer margin often fringed with plumose hairs;
dactyl sinuous, fingers closing closely, a thick tuft
of pubescence below. Walking legs rugose; an-
terior margin of meri with fringe of plumose
hairs; all articles covered with long, nonplumose
setae; anterior margin of first and second legs
with six to nine spines, third with five to seven;
merus of first and second with a posterodistal
spine.

Sternum, sternal plastron, abdomen, ventral
surface of outer maxillipeds, chelipeds, and walk-
ing legs covered with strong striations.

Measurements. — Length of carapace: males, 7
to 17 mm.; non-ovigerous females, 6 to 11 (15?)
nun. ; ovigerous females, 7 to 14 mm. (Haig, 1960 ;
Holthuis, 1959).

Color. — Grayish brown without markings in
life; in alcohol, light brown with purple or dark-
red lines and dots on rugae (Hay and Shore,
1918). Spaces between rugae yellow; lower sur-
face, including abdomen, deep red (Faxon in
Haig, 1960).

Habitat. — Under stones and associated with
sponges, corals, and anemones in littoral ; in some-
what deeper water, from sand and sand-shell bot-
tom (Haig, 1960) ; low- water mark to 27 fathoms.

Type locality. — Unknown.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

107

Known range. — Cape Hatteras, N.C., through
Gulf of Mexico and Caribbean area to Rio de
Janeiro, Brazil; Uha Trinidade off Brazil; Pa-
cific Ocean from region around Panama City;
Isla San Lucas, Costa Rica; off La Libertad,
Ecuador.

Remarks. — A full review of this species has
been given by Haig (1956, 1960). Ovigenous fe-
males are known from the Caribbean area from
January to May, and from North Carolina and
the Gulf of Mexico from June to September
(Haig, 1956, 1960; Holthuis, 1959, in part).

Rathbun (1926) described a fossil species, P.
avitus, from the Pliocene of Central America
which is similar to the recent P. galathinus.

Genus Pachycheles Stimpson, 1858

Stimpson, 1858, p. 228.— Haig, 1960, p. 131 (rev.).

Pachycheles pilosus (H. Milne Edwards)

Figure 84

Porcellana pilosa H. Milne Edwards, 1837, p. 255.
Pachycheles pilosus: Haig, 1956. p. 11 (rev.).

Recognition characters. — Carapace slightly
broader than long, flattened but somewhat more
convex from front to back than side to side,
lightly rugose along sides, with numerous short,
transverse tufts of setae except scattered setae on
frontal region. Frontal margin sinuous, slightly
produced in middle, with a submarginal row of
stout setae. Anterolateral margins emarginate.
Epimeral pieces of metabranchial regions sepa-
rated by membranous interspaces, posterior por-

Figi re 84. Pachycheles pilosus (Milne Edwards). Ani-
mal in dorsal view, second, third, ami fourth leg of lefl
side not shown, 5 mm. Indicated.

tion consisting of one or more pieces. Orbits
deeply excavated, postorbital angle spiniform;
eyes short, stout. Antenna with first movable
article bearing a buttressed spine on anterior mar-
gin; second article with a spine near middle of
anterior border; third article short, smooth.

Chelipeds unequal, stout, ornamented with
numerous, long, dark setae with shorter ones be-
tween; merus outlined dorsally with long setae, a
stout spine and large white tubercle at inner distal
angle; carpus with a number of prominent white
tubercles on proximal portion, anterior border
with about three spines; hand inflated, outer mar-
gin spined and tuberculate below and at base of
immovable finger, fingers short, immovable finger
with a single blunt tooth on cutting edge, inner
edge of hand and dactyl with obsolescent spines.
Walking legs with hairy covering similar to che-
lipeds, a few spines below on dactyls and propodi.

Telson of males and females with five elements.

Measurements. — Length of carapace: males, 7
mm.; ovigerous females, 5 to 7 mm. (Haig, 1956).

Habitat. — In corals; to 4 fathoms (Schmitt,
1935a).

Type locality. — Vicinity of Charleston, S.C.

Known range. — Charleston, S.C. ; Key West to
Sarasota Bay, Fla. ; through West Indies to To-
bago and Aruba.

Remarks. — Ovigerous females have been taken
in the West Indies from February to May (Haig.
1956, in part). Rathbun (1926) reported a Plio-
cene species of Pachycheles from Central
America.

Pachycheles rugimanus Milne Edwards

Figure 85

Pachycheles rugimanus Milne Edwards, 1880, p. 36. — Hay and
Shore, 1918, p. 404, pi. 29, fig. 2.— Haig, 1959, p. 12 (rev.).

Recognition characters. — Carapace slightly
longer than wide except in mature females, flat
from side to side, convex from front to back, ru-
gose along sides; anterolateral margins emargi-
nate; epimeral pieces of metabranchial regions
separated by membranous interspaces, posterior
portion consisting of one or more pieces. Front
broad, frontal margin projecting downward,
slightly produced in middle, hardly visible from
above. Orbits deeply excavated, margins slightly
raised, postorbital angle spini form : eyes short,
stout, retract ile. Antenna with first movable
art icle bearing a serrate spine on anterior margin :

108

FISH AND WILDLIFE SERVICE

Figure 85. — Pachycheles rugimanus Milne Edwards. Ani-
mal in dorsal view, second, third, and fourth legs of left
side not shown, 5 mm. indicated.

second article with a row of unequal spines on
anterior border ; third article short, smooth.

Chelipeds subequal, stout; merus crossed by a
rew rugae distally, a rugose and serrate spine at
inner distal angle; carpus with four anterior
spines, graded in size, proximal one largest, and
upper surface with four prominent longitudinal,
tuberculate ridges, with deep channels between,
channels crossed by irregular septae forming rows
of oblong pits between ridges; ridges and pitted
channels continued on hand but with less regu-
larity in arrangement; fingers tuberculate almost
to tips. First three pairs of walking legs stout and
with distal articles hairy ; last legs weak and re-
flexed dorsally.

Telson of male and female with five elements;
male pleopods present.

Measurements. — Carapace: male, length, 8
mm.; width, 7 mm.; ovigerous female, length, 8
mm., width, 9 mm.

Color. — Brownish red, fingers vermilion.

Habitat.— To depth of 79 fathoms (Schmitt,
1935a).

Type locality. — Contoy, and west of Florida.

Known range. — Off Cape Lookout, N.C.,
through Florida to St. Thomas, V.I., and Contoy
Island, Mexico.

Remarks. — Only a few collections of this spe-
cies have been recorded, from widely scattered
localities. Ovigerous females have been taken in

February and March from the Carolinas and west
Florida, and in September in North Carolina and
east Florida.

Genus Euceramus Stimpson, 1860

Stimpson, 1860b, p. 445. — Haig, 1960b. p. 187.

Euceramus praelongus Stimpson

Figure 86

Euceramus praelongus Stimpson, 1860b, p. 444. — Hay and
Shore, 1918, p. 405, pi. 29, fig. 3.— Haig, 1956, p. 7 (rev.).

Recognition characters. — Carapace subcylin-
drical, elongate; sides slightly arcuate, with mi-
nute, irregular, transverse rugae; anterolateral
margins with two more or less obtuse spines on
each side behind antennae. Front tridentate,
median spine about twice length of lateral spines,
a broad V-shaped depression at rear edge of cara-
pace. Eyes well developed. Antennule short.
Antenna about three- fourths length of body, fla-
gella sparsely covered with fine hairs; basal
article short, not produced forward; movable
articles not far removed from orbit. Third maxil-
liped large, forming subquadrate shield extending
laterally almost to edge of carapace.

Figube 86. — Euceramus
praelongus Stimpson.
Animal in dorsal view,
fifth leg only of left side
shown, 5 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

109

Chelipeds stout, subequal; hand slightly
roughened and hairy, somewhat stouter in males
than in females; fingers about as long as palm,
more gaping in males than in females. First pair
of walking legs shorter than second and third
pairs; last pair reduced and turned dorsally.

Abdomen small, distal segments narrow. Uro-
pods reduced. Telson longer than broad, com-
posed of seven elements.

Measurements. — Length of carapace from tip
of rostrum to center of rear notch: males, 14
mm. ; females, 14 mm.

Color. — Background of carapace greenish gray
to greenish tan with lighter and darker lines of
color delineating striae and marginal furrow; a
light longitudinal stripe, broadest anteriorly,
along middorsal line; purplish markings along
lines separating major regions of carapace; legs
mottled with greenish gray or tan as on carapace;
a suggestion of iridescence on body and legs
(from specimen collected by L. McCloskey, More-
head City Harbor, N.C., August 7, 1962).

Habitat. — Sandy beaches below waterline, and
on broken-shell bottoms; low-water mark to 21
fathoms.

Type locality.- — Beaufort, N.C.

Known range. — Chesapeake Bay, off South
Marsh Island, to Aransas area of Texas coast.

Remarks. — Hay and Shore (1918) and Haig
(1956) remarked that this is a rare species and it
is true that it has seldom been collected, but the
habits described by Pearse, Humm, and Wharton
(1942) suggest that it is like a number of similar
decapod crustaceans which are rare in collections
chiefly because they live where they escape the at-
tention of most collectors. Pearse, Humm, and
Wharton described E. praelongus as a dweller of
sandy beaches, similar in habit to Emerita, Lepi-
dopa, and Ogyrides. It is also found on rubble-
covered bottom. The animal is a highly adapted
burro wer which burrows backward. It scrapes
food caught in the hairy antennae with setose
mouth parts. Juvenile specimens are occasionally
taken at night in plankton tows near inlets in
North Carolina, and ovigerous females have been
taken in May.

Haig (1960) placed Euceramus between the
group of ]X>rcellanid "genera in which the basal
antennal segment is short and not broadly in con-
tact with the anterior margin of the carapace, and

the group of genera in which the basal segment is
strongly produced forward so that the movable
segments are far removed from the orbit."

Genus Porcellana Lamarck, 1801

Lamarck, 1801, p. 153.— Haig, 1960, p. 196 (rev.).

Porcellana sayana (Leach)

Figure 87

Pisidia sayana Leach, 1820, p. 54.

Porcellana sayana: Hay and Shore, 1918, p. 403, pi. 29, flg. 7. —
Haig, 1956, p. 31 (rev.).

Recognition characters. — Carapace usually a
little longer than wide, depressed; dorsal surface
slightly convex, meeting lateral parts in a slight
shoulder a little behind base of antenna; surface
minutely granulate and with fine oblique dorsal
plications along sides, especially on posterolateral
portions; a few scattered small clumps of hairs.
Rostrum triangular, concave above, tip abruptly
decurved, margins spinulate or tuberculate. Orbit
with a strong tooth near inner angle, separated
from orbit by a wide and rather deep notch ; outer
angle produced into a broad, low tooth. Eyes well
developed. Cervical groove lightly impressed.
Antennae slender, smooth, longer than carapace;
basal article strongly produced forward into a
spinelike projection ; movable articles far removed
from orbit.

Figure 87. — Porcellana sayana (Leach). Auimal in dor-
sal view, legs of left side not shown, 5 mm. indicated.

110

FISH AND WILDLIFE SERVICE

Chelipeds strong, heavy, finely plicate, nearly
smooth in old individuals; hand as long as or
longer than carapace, outer margin fringed with
long hairs except in old individuals; fingers short,
curved, and bent ; proximal inner angle of carpus
and distal inner angle of merus produced, form-
ing lobes, both articles with scattered hairs near
dorsolateral border, posterodistal angle of carpus
ending in a spine. First three pairs of walking
legs normal, with scattered hairs; last pair re-
duced and carried above others.

Telson composed of seven elements.

Measurements. — Carapace : males, length, 4 mm.
(Wass, 1955), width, 12 mm.; nonovigerous fe-
males, length, 8 mm., width, 8 mm. ; ovigerous fe-
males, length, 5 mm. (Haig, 1956) to 10 mm.,
width, 10 mm. Specimens with length and width
equal are unusual.

Color. — Ground color reddish or rusty brown;
covered on all dorsal surfaces and abdomen with
complicated irregular pattern of yellowish white,
yellow, and some bluish-white spots or longi-
tudinal stripes; stripes more prominent on rear
center part of carapace and on abdomen. Pattern
quite variable in shape and shade, some specimens
being predominantly light.

Habitat. — This species is often taken in the
dredge in various parts of Beaufort Harbor, N.C.,
and along the neighboring coast. It has also been
taken from among rocks of the jetties near Fort
Macon. It is often found in crevices in clusters of
oyster shells or as a commensal of the hermit crabs
Pagurus pollicaris or Petrochirus diogenes in the
shell of some gastropod. Hildebrand (1954)
found specimens attached to the decorator crab,
Stenocionops furcata. Shallow water to 48
fathoms; (390 fathoms(?), Schmitt, 1935a).

Type localities. — Coast of Georgia and Florida.

Known range. — Cape Hatteras, N.C., around
Gulf of Mexico and Caribbean Sea to Bahia Cale-
donia, Panama; through West Indies to Vene-
zuela and Surinam (Haig, 1956; Holthuis, 1959).

Remarks. — This species is rather abundant off
the Carolinas and in the western Gulf of Mexico
( Hildebrand, 1954, 1955). Ovigerous females are
known to occur from January to November in
various localities throughout the range. In North
Carolina, they are known in January and from
June to November. Brooks and Wilson (1883)
described the first zoeal stage of P. sayana. A long

breeding season is indicated, as is true of a close
relative in the Pacific, Porcellana cancrisocialis.
Haig (1960) suggested that these forms may be
conspecific.

Porcellana sigsbeiana Milne Edwards

Figure 88

Porcellana eigsbeiana Milne Edwards, 1880, p. 35. — Benedict,
1901, p. 137. — Milne Edwards and Bouvier, 1923, p. 292, pi. 1, fig.
6. — Haig, 1956, p. 3i3 (rey.).

Figure 88. — Porcellana sigsbeiana Milne Edwards. Ani-
mal in dorsal view, fifth leg only of left side shown, 5
mm. indicated.

Recognition characters. — Carapace longer than
wide, evenly convex in posterior half, broadly
ridged in gastric region; lateral margins thin,
produced, and slightly upturned; surface faintly
rugose. Front strongly tridentate; rostrum ex-
ceeding narrower lateral teeth, irregularly pen-
tagonal with sides adjacent to base subparallel.
Orbit with outer angle produced into a broad,
oblique tooth ; eyes well developed. Anterolateral

MARINE DECAPOD CRUSTACEANS OF THE CAROLESTAS

111

borders concave, ending in a shoulder separated
from acute marginal tooth by an elongate notch
at terminus of cervical groove. Antennae slender,
smooth, about as long as carapace; basal article
strongly produced forward in a spinelike projec-
tion; movable articles far removed from orbit.

Chelipeds strong, heavy, smooth; hand longer
than carapace, outer margin fringed with hairs;
fingers less than half as long as palm, nearly
straight, hooked at tips; length of carpus more
than 1.5 times width, a single small spiniform
tooth on anterior border; merus with a single
broad tooth on lobe at internal angle. First three
pairs of walking legs with scattered tufts of
hairs ; last pair reduced and carried above others.

Telson composed of seven elements.

Measurements. — Male carapace : length, 24 mm.,
width, 22 mm.

Color. — Colored with an irregular pattern of
reddish longitudinal mottlings on a white back-
ground (specimens preserved in alcohol).

Habitat. — The species occurs near the edge of
the Continental Shelf in North Carolina, and is
usually found in deeper water than the related
and similar species, Porcellana sayana; 27 to 215
fathoms.

Type localities. — Blake Stations: 49, off delta
of Mississippi River, 118 fathoms; 36, north of
Yucatan, 84 fathoms; 142, Flannegan Passage
[V.I.],27 fathoms.

Known range. — Off Marthas Vineyard, Mass.,
to northern Gulf of Mexico and southern Gulf of
Mexico off Yucatan; West Indies to Virgin Is-
lands.

Remarks. — Ovigerous females have been taken
in April, May, June, and November off northwest
Florida, Alabama, Mississippi, and Louisiana,
and in midwinter off Yucatan. Benedict (1901)
was correct in stating that this is the largest
porcellanid species in the region.

Genus Megalobrachium Stimpson, 1858

Stlmpson, 1858, p. 228.— Haig, 1960, p. 212.

Megatobrachium soriatum (Say)
Figure 89

Porcellana soriata Say, 1818, p. 456. — Hay and Shore, 1918,
p. 404, pi. 29, flg. 6.

Porcellanopsia soriata: Halg, 1956, p. 35.

Megalobrachium eoriatum: Haig, 1960, p. 227 (rev.).

Recognition characters. — Carapace somewhat
hexagonal, slightly wider than long; margins

more or less hairy; areolations well marked, some
tuberculate. Front rounded in dorsal view, tri-
lobate in frontal view; rostrum little, if any,
longer than lateral teeth. Orbits well defined;
eyes well developed. Antennae about as long as
carapace; basal article strongly produced forward
and broadly in contact with margin of carapace;
movable articles slender and removed from orbit.

Chelipeds long and heavy, roughly tuberculate ;
hand fringed with long hair along lower margin
and with tubercles in rather well-defined rows;
fingers with white, strongly hooked tips; carpus
with one strong spine and some smaller spines
on anterior border, dorsal aspect with tubercles
irregularly arranged and appearing granulate
under slight magnification; merus ornamented
like carpus distally. First three walking legs
stout, hairy, and with sharp, curved dactyls; last
legs weak and placed above others.

Telson divided into five elements.

Measurements. — Carapace: length of male, 5
mm., width, 5.5 mm.; ovigerous females, length,
4 to 5 mm., width, 4 to 5.5 mm.

Color. — In life a dirty gray ; in alcohol a rusty
or grayish red.

Habitat. — Free living among corals, rocks, and
sponges; in North Carolina found especially in
canals of sponges taken from fishing banks off-
shore near Beaufort Inlet (Hay and Shore, 1918;

Figure 89. — Megalobrachium soriatum (Say). Animal in
dorsal view, second, third, and fourth legs of left side
not shown, 1 mm. indicated.

112

FISH AND WILDLIFE SERVICE

Pearse and Williams, 1951). Wass (1955) found
the species in sponges of the genus Ircinia in
Florida. Near low-water mark to 37 fathoms.

Type locality. — St. Catherines Island, Ga.

Known range. — Off Cape Hatteras, N.C., to
Port Aransas, Tex.; West Indies to Barbados;
Contoy, Mexico; Bahia Caledonia, Panama.

Remarks. — This small porcellanid crab has had
a varied taxonomic history. First, Say's trivial
name was misspelled by subsequent authors (so-
ciata for soriata), as pointed out by Benedict
(1901), and second, the generic designation has
been changed four times as understanding of
relationships has been variously interpreted.
Chace '(1942) shifted soriata from Porcellana to
Porccllanopsis. The most recent reviser (Haig,
1960), after reviewing all species referred to
Megalobrachium and Porcellanopsis, deemed it
best to combine all forms in a single genus.

A close congener of the eastern Pacific is M.
tuberculvpes (Lockington), and Haig suggested
that they may not be distinct.

Ovigerous females have been taken off the
Carolinas in June, July, and August, and in July
in Florida (Wass, 1955).

Genus Polyonyx Stimpson, 1858

Stimpson, 1858, p. 233.— Haig, 1960, p. 232.

Polyonyx gibbesi Haig

Figure 90
Porcellana macrocheles Gibbes, 1850, p. 191.
Polyonyx macrocheles: Hay and Shore, 1918, p. 405, pi. 29,
fig. 8.

Polyonyx gibbesi: Haig, 1956, p. 28 (rev.).

Figure 90. — Polyonyx gibbesi Haig. Female in dorsal
view, second, third, fourth, and fifth legs of left side not
shown, 5 mm. indicated.

Recognition characters. — Carapace smooth,
finely plicate, transversely oval, about one-fourth
to one-third wider than long; front hardly pro-
duced, margin slightly sinuous; posterolateral
portions with scattered, feathered hairs; infolded
lateral portions separated from rest of carapace
by a deep fissure. Orbits small, eyes small, cornea
reduced. Antenna slender, about 1.5 times as long
as body ; basal article strongly produced forward ;
movable articles far removed from orbit.

Chelipeds unequal, long and distorted; larger
hand nearly twice as long as carapace; superior
margin of hands convex, with thin fringe of
plumose hairs, inferior margin nearly straight,
with fringe of long plumose hairs; distal two-
thirds of propodus with single row of fine, close-
set, subtruncate teeth, larger and less closely set
distally (row longer on small hand) ; fingers
short, hooked at tip, toothed on cutting edges,
dactyl falciform, sparsely hairy (straighter on
small hand) ; carpus as long as palm, thick, an-
terior margin produced into a thin crest, proximal
end markedly subrectangular, entire margin with
fringe of fine plumose hairs, a thinner fringe of
shorter hairs on outer margin ; merus subcubical,
finely rugose above, upper margin produced in
front, plumose-hairy dorsolaterally. First three
pairs of walking legs sparsely hairy, last pair
with long tuft on chela and distal end of carpus;
merus of second and third legs spinulose below,
dactyls of first to third legs with four corneous
spines on internal margin closing against weaker
spines on distal portion of propodus.

Measurements. — Carapace: male, width, 11
mm. ; nonovigerous female, length, 9 mm., width,
13 mm.; ovigerous female, width, 16 mm.

Color. — Grayish white, sometimes stained with
brown.

Habitat. — A common commensal of the an-
nelid Chaetopterus variopvdatus [ = pergament-
aceus], seldom found outside tubes of this worm;
intertidal to 8 fathoms.

Type locality. — Coast of South Carolina.

Known range. — Woods Hole, Mass. ; Rhode Is-
land; Beaufort, N.C., to Alligator Harbor, Fla.;
Puerto Rico ; Bahia Caledonia, Panama. Notes in
Haig's (1956) account for P. gibbesi indicate that
the species may range to Brazil.

Remarks. — It is unfortunate that this distinc-
tive species, known so long under the name Poly-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

113

onyx macrocheles (Gibbes) , should have to under-
go a name change, but Haig (1956) has shown
that Porcellana macrocheles Gibbes, 1850, is a
homonym of Porcellana macrocheles Poeppig,
1836, hence unavailable. The substitute name is
quite appropriate, however, for it not only honors
the original describer but is applied to a species
common in the area where he worked.

Unlike other porcellanids occurring in the
Carolinas, Polyonyx gibbesi has been the subject
of some ecological observations. Enders (1905),
at Beaufort, N.C., and Pearse (1913), at Woods
Hole, Mass., studied commensal inhabitants of the
tubes of Chaetopterus variopedatus, finding P.
gibbesi to be common commensals in both areas.
Both authors found usually a male and a female
crab in the same tube, but Enders found six
isolated ovigerous females in the course of a
summer. Pearse found the species to be strongly
thigmotactic, and crabs, seemingly too large to
enter Chaetopterus tubes, entered and left an
artificial tube at will in the laboratory.

Individuals usually moved backward or side-
ways on open sand, using the chelipeds as an aid
in walking, or at times swam clumsily upside
down by flapping the abdomen. Individuals
showed little ability to burrow. The respiratory
mechanism seemed well adapted to life in confine-
ment, for the respiratory currents were strong and
capable of being directed, changing with the
change in direction of waterflow in the worm tube.
Crabs in an experimental tube tolerated consider-
able fouling of the water.

Pearse gave an excellent figure of the detailed
structure of the chelate and tufted fourth walking
legs which are used extensively in the meticulous
preening characteristic of this species. The plumes
of hairs on the appendages, especially those on the
third maxillipeds, are used as nets for capturing
food from water currents.

Gray (1961) reviewed the life history and ecol-
ogy of the species. He found that the breeding
season at Beaufort, N.C., extends at least from
April to December, and ovigerous females are
otherwise known in February and March from
Florida. Usually when a pair of P. gibbesi is
found in a tube, adult crabs of no other species
are present at the same time. The smallest female
with eggs was 8.4 mm. in width. Gray concluded

that the crabs enter worm tubes by chance, not in
response to attractants.

In the years since Enders' and Pearse's studies,
the proportion of Pinnixa chaetopterana to Poly-
onyx gibbesi at Woods Hole and Beaufort has
changed. Woods Hole; Polyonyx-Pinnixa; 1913,
22:78; 1959, 66:34. Beaufort; 1905, 83:17;
1958-59, 39: 61. Gray (1961) postulated that the
more southerly species, P. gibbesi, has increased in
the Woods Hole area due to amelioration of cli-
mate. In the Beaufort area, decline may be due to
recent hurricane damage which destroyed many
Chaetopterus tubes. Gray also found that P. gib-
besi prefers less muddy bottoms than P. chaetop-
terana. He considered P. gibbesi an obligate com-
mensal of Chaetopterus.

Faxon (1879) discussed the last stage zoea of P.
gibbesi and determined that it molts directly into
the first crab stage with no intervening megalops
as in brachyurans. Smith (1880b) reported
swarms of zoeae of P. gibbesi at the edge of tidal
currents near the mouth of Narragansett Bay in
summer.

Superfamily Paguridea

Carapace elongate and subcylindrical, or broad
and crablike ; front not fused with epistome. Ab-
domen soft, asymmetrical, and spirally coiled,
merely bent or flexed against thoracic sterna as in
Brachyura, or rarely symmetrical, straight and
well calcified dorsally. Tail fan usually present
and asymmetrical, occasionally symmetrical. Eyes
never in orbits. Antennal peduncle five jointed;
second article almost always with a movable
acicle. First pair of legs chelate and usually
large; fifth pair always, and fourth pair com-
monly, much less developed than preceding pairs.
Abdominal appendages usually unpaired on sec-
ond to fourth, or second to fifth segments, and
usually present only on left side (Alcock, 1905).

Family Paguridae. Hermit crabs

Carapace usually somewhat elongate and
broadened posteriorly, sides membranous, and
covered with a network of very thin lines ordi-
narily limited above by linea anomurica. Abdo-
men generally soft and spirally coiled in adapta-
tion to gastropod shells (abdomen secondarily
symmetrical in a few forms using other kinds of

114

FISH AND WILDLIFE SERVICE

housing). Eye scales triangular. Thoracic
sternites, corresponding to third, fourth, and fifth
legs, free and mobile. Legs four and five reduced
and modified. Middle terga of abdomen separated
more or less by membrane (adapted from Alcock,
1905 ;Bouvier, 1940).

Remarks. — A most useful bibliography of this
group was published by (Jordan (1956). The
family Paguridae has a long fossil record in
North America. Species of Paguristes, Petro-
chirus, and Pagurus are known from the Creta-
ceous, and Dardanus from the Eocene (Rathbun,
1935).

KEY TO SUBFAMILIES IN THE CAROLINAS

a. Third maxillipeds approximated at base ; ehelipeds
subequal, or left much larger than right, rarely with
right slightly larger than left Diogeninae (p. 115).

aa. Third maxillipeds widely separated at base by a
sternum ; right eheliped usually much larger than left,
left never larger than right, occasionally subequal

Pagurinae (p. 125).

Subfamily Diogeninae

The chief distinguishing characters are given in
the above key.

KEY TO GENERA AND SOME SPECIES OF
DIOGENINAE IN THE CAROLINAS

a. Paired appendages present on first two abdominal seg-
ments of male, and first abdominal segment of female ;
fingers of ehelipeds opening and closing horizontally

Pagnristes (p. 115).
aa. No paired appendages on anterior abdominal seg-
ments in either sex.

b. Fingers of ehelipeds opening and closing horizon-
tally Clibanarius rittatus (p. 120).

bb. Fingers of ehelipeds opening and closing obliquely
or nearly vertically.

c. Chelipeds not markedly unequal, right usually
slightly larger than left

Petrochirus diogenes (p. 122).

cc. Chelipeds markedly unequal, left much larger

than right Dardanus (p. 123).

Genus Paguristes Dana, 1852

Provenzano, 1959, p. 381 (rev.).

KEY TO SPECIES IN THE CAROLINAS

a. Rostrum broadly rounded, or pointed, but not advanced
beyond level of lateral projections on front,
b. Anterolateral sides of anterior shield of carapace

not spiny moorei (p. 115).

bb. Anterolateral sides of anterior shield of carapace

definitely spiny lymani (p. 116).

aa. Rostrum slender, and definitely advanced beyond
level of lateral projections on front,
b. Anterior shield of carapace not noticeably longer
than broad,
c. Frontal and lateral margins meeting at almost a

right angle sericeus (p. 117).

cc. Frontal and lateral margins meeting at broadly

obtuse or rounded angle triangiilatus (p. 118).

bb. Anterior shield of carapace noticeably longer than
broad.

c. Eye scales acuminate spinipes (p. 118).

cc. Eye scales with three or four (occasionally two)
terminal spines tortugae (p. 119).

Paguristes moorei Benedict

Figure 91

Paguriatea moorei Benedict, 1901, p. 144, pi. 4, fig. 3. — Hay
and Shore, 1918, p. 409, pi. 30, fig. 3.

Recognition characters. — (Taken from holo-
typic female.) Anterior shield of carapace
slightly longer than broad ; upper surface of cara-
pace with a few scattered hairs and irregular
punctations, more or less iridescent. Rostrum
short, obtusely pointed, slightly less advanced
than more acute lateral projections. Eyestalks
slender, slightly dilated distally, slightly longer

Figure 91. — Paguristes moorei Benedict. Type
female, anterior part of body in dorsal view,
approximately X 5 (after Benedict, 1901).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

115

than width of anterior shield (8.6 mm.) ; eye
scales not adjacent, anterior process acute. Anten-
nular peduncle slightly exceeding eyestalk when
extended. Antennal peduncle extending slightly
beyond middle of eyestalk ; flagellum not exceed-
ing tips of legs, with scattered setae; acicles
bispinose at tip (right spine on right acicle
broken), a row of four strong spines on proximal
two-thirds of inner side (right acicle with a
single external spine) .

Chelipeds subequal but of similar form, medial
margins nearly straight; hands short and thick,
covered dorsally with many tubercles and hairs,
but nearly smooth ventrally, a row of strong
spines on upper medial border of palm, edges of
fingers fitting closely ; carpus similar to hands but
with fewer tubercles in two rows, largest tubercles
on medial upper border; merus prismatic with
tubercles on angles. First pair of walking legs
with a row of spines along upper margin of
carpus and propodus.

Measurements. — Carapace (holotypic female) :
length in midline, 13.2 mm., width, 11.8 mm.;
anterior shield, length, 8.5 mm., width, 8.3 mm.

Color. — Yellowish, eyestalks deep orange or
crimson below, and white above (Hay and Shore,
1918).

Habitat. — From near edge of continental shelf
in North Carolina.

Type locality. — Puerto Rico.

Known range. — Gulf Stream about 30 miles
south of Cape Lookout, N.C. ; Puerto Rico.

Remarks. — The species is known from only two
specimens. The type only is extant.

Paguristes lymani Milne Edwards and Bouvier

Figure 92

Paguristes lymani Milne Edwards and Bouvier, 1893, p. 49,
pi. 4. tigs. 13-22. — Benedict, 1901, p. 145, pi. 4, fig. 8.— Alcock,
1905, p. 157.

Recognition characters. — Anterior shield of
carapace slightly broader than long, sides a little
hairy and roughened by spiny granules; postero-
lateral corners notched. Rostrum often a rounded
lobe falling far short of pointed lateral projec-
tions; front rounding gradually to lateral mar-
gins from lateral projections. Eyestalks some-
what dilated at base and longer than distance be-
tween apices of lateral projections of front; eye
scales singly acuminate or with up to three un-
equal spines on anterior border, long hairs some-

Figdbe 92. — Paguristes lymani Milne Edwards and Bou-
vier. A, anterior part of body in dorsal view ; B, right
chela, outer surface ; 5 mm. indicated.

what obscuring tip. Antennular peduncles highly
variable, exceeding eyestalks from less than half
to entire length of terminal article. Tips of anten-
nal peduncles extending to base of cornea, or
slightly beyond eyes; acicles extending to three-
fourths length of eyestalks, terminated by a spiny
fork and often with three to five spinules on in-
ternal or external borders, external spine at base
of acicle also spinulose on outer margin.

Chelipeds small, subequal, and similar; hands
about twice as long as broad, upper surface
covered with rather large tubercular granules,
many with corneous tips, and four spines on in-
ternal margin of palm; lower margin of palm con-
cave at base of immovable finger; fingers slightly
agape, terminated by corneous tips preceded by
finely denticulate cutting edges, dactyl with four
or five small teeth behind corneous portion;
carpus witli three rows of spines on upper surface,
four or five large ones on inner margin, about six
on outer margin (with distalmost largest), and

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FISH AND WILDLIFE SERVICE

about six more on upper surface near inner mar-
gin ; superior border of merus armed with more or
less pointed projections, feebly rugose externally;
spines of palm, carpus, and merus obscured by
feathered hairs. Walking legs with long hairs,
particularly on upper and lower borders of
dactyls; spines on crest of carpus, propodus, and
base of dactyl, and somewhat reduced ones on
inner and outer sides of propodus and carpus
where rows appear mixed with hairs; dactyls
arched, somewhat shorter than combined length of
two preceding articles, and terminated by a coni-
cal claw.

Measurements. — Length of carapace : males, 13
mm. ; ovigerous females, 11 mm.

Variations.— The spination of the chelipeds
may vary in strength and density. The length of
the antennular peduncles, in relation to the eye-
stalks, is highly variable. The eye scales become
more dentate with age [implied]. The rostrum
may reach the level of the lateral projections of
the front, and small individuals tend to be hairier
than large ones (Milne Edwards and Bouvier,
1893).

Habitat. — Literature and museum records show
that this species has been found housed in small to
medium-sized shells belonging to the families Cas-
sididae, Dentaliidae, Nassariidae, Ovulidae, Muri-
cidae, Trochidae, Turridae, and Volutidae; 15 to
878 fathoms.

Type locality. — Sand-Key, [Fla.], 15 fathoms.

Known range. — Southeast of Cape Lookout,
N.C. (82-100 fathoms) ; Florida Keys to Swan
Island off Honduras; through West Indies to
British Guiana.

Remarks. — Ovigerous females have been taken
in February from North Carolina and Florida, in
May and June from Florida, and in November
from British Guiana.

Paguristes sericeus Milne Edwards
Figure 93

Paguristes sericeus Milne Edwards, 1880. p. 44. — Milne Ed-
wards and Bouvier, 1893, p. 46, pi. 3, figs. 14-22. — Provenzano,
1961, p. 155.

Paguristes rectijrons Benedict, 1901, p. 145, pi. 4, flg. 7.

Recognition characters. — Anterior shield of
carapace nearly as broad as long, flattened, with
several spines on each side; frontal margin as
long as ocular peduncles, making nearly a right
angle with lateral margins; lateral projections

Figure 93. — Paguristes sericeus Milne Edwards. A,
anterior part of body in dorsal view; B, right chela,
outer surface ; 3 mm. indicated.

low but terminating in a small spine. Rostrum
with acute tip reaching along approximately half
length of eye scales. Ocular peduncles slightly
narrowed in middle; eye scales small, acuminate
at tip. Antennular peduncles extending almost
to tips of eyestalks. Antennal peduncles slightly
exceeding acicles, terminal article armed with two
spines; acicles straight, terminated by a spiny
fork and with two or three spines on internal and
external borders.

Chelipeds subequal, and rather short and
broad; upper surface of hands and carpi with
soft, silky, yellow hairs nearly obscuring surface,
many strong granulations becoming corneous at
tips scattered over upper surface. Walking legs
not reaching much beyond extended chelipeds;
dactyls regularly curved, dactyl of first walking
leg 1.5 times length of propodus, of second as
long as propodus and carpus combined.

Measurements. — Length of carapace: approxi-
mately 20 mm. (Milne -Edwards and Bouvier,
1893).

Variations. — There is apparently some varia-
tion in straightness of the front and length of the
eyestalks, as judged by the accounts of Milne

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 0-^65-^9

117

Edwards and Bouvier (1893) and Benedict
(1901).

Color. — Body reddish with white spotting; eye-
stalks not spotted but solid orange red (from re-
cently preserved specimen and from Provenzano,
1959, 1961).

Habitat. — Coral rubble and sand; found in
Strombus, Murex, and Oliva (Provenzano, 1961,
and various authors) ; 5 to 36 fathoms.

Type locality— -Lat. 24°34' N. long. 83°16' W.
[near Dry Tortugas, Fla.], 36 fathoms.

Known range. — Off Cape Lookout, N.C. ; Flor-
ida Keys to Virgin Islands.

Remarks. — Ovigerous females are known from
the Virgin Islands in April (Provenzano, 1961).

Paguristes triangulatus Milne Edwards and Bouvier

Figure 94

Paguristes triangulatus Milne Edwards and Bouvier, 1893, p.
40, pi. 4, figs. 6-12.— Benedict, 1901, p. 146, pi. 4, fig. 9. — Aleock
1905, p. 157.

Recognition characters. — Carapace somewhat
hairy toward sides, and with scattered hairs on
anterior shield ; shield a little longer than broad ;
front with a thickened margin and a pointed
rostrum reaching well beyond broadly angular
lateral projections. Eyestalks long, slightly
dilated, but obliquely compressed at tips, a line
of hairs along dorsal side; eye scales acuminate,
a little rugose on internal border. Antennular
peduncles with about half of terminal article ex-
tending beyond eyestalks. Antennal peduncles ex-
tending to base of cornea or as little as three-
fourths length of eyestalks; acicles reaching
about to middle of eyestalks, spinose on internal
and external borders, tip often bifurcate.

Chelipeds subequal, similar, upper surfaces
tuberculate and hairy; inner margin of hands,
carpi, and bases of dactyls with strong spines
corneous at tips; upper surfaces of carpi and meri
with a few spines and spiniform tubercles corne-
ous at tips. First walking legs with spiny crest
on carpi, propodi, and base of dactyls, crest ob-
solescent on second pair, both pairs hairy dor-
sally; dactyls curved, about as long as two pre
ceding articles together; dactyls of right side a
little weaker than left and laterally compressed;
proximal end of first left dactyl with cross section
in form of curvilinear triangle, broadly rounded
internal face serving as base and obtusely pointed

Figure 91. — Paguristes triangulatus Milne Edwards and
Bouvier. A, anterior part of body in dorsal view, ap-
proximately X 3 (after Benedict, 1901) ; B, right chela,
outer surface, 3 mm. indicated.

external face serving as apex; second left dactyl
a little stronger.

Measurements. — Length of carapace: male, 11
mm. ; ovigerous female, 12 mm.

Color. — Legs and anterior part of cephalo-
thorax tinted pink (Milne Edwards and Bouvier,
1893); eyestalks pink (Benedict, 1901).

Habitat. — One specimen has been reported from
a shell of Murex (Milne Edwards and Bouvier,
1893) ; 6.5 to 82 fathoms.

Type locality. — Barbados, 73 fathoms.

Known range. — Off Oregon Inlet, N.C. (6.5
fathoms) ; Tortugas, Fla.; Barbados-; Trindad.

Remarks.- — Ovigerous females have been taken
from Florida in August and October.

Paguristes spinipes Milne Edwards
Figure 95

Paguristes spinipes Milne Edwards, 1880, p. 44. — Milne Ed-
wards and Bouvier, 1893, p. 33. pi. 3, figs. 1-13. — Benedict, 1901,
p. 145, pi. 4, fig. 6.— Alcoek, 1905, p. 157.— Boone, 1927, p. 76.

Paguristes visor Henderson. 1888, p. 78, pi. 8, fig. 3.

Paguristes armatus Hay, 1917, p. 73.— Hay and Shore, 1918, p.
409, pi. 30, fig. 7.

Recognition characters. — Anterior shield of
carapace convex, considerably longer than broad ;
frontal margin thickened and drawn out into an
almost straight-sided, acute rostrum, with tip con-

118

FISH AND WILDLIFE SERVICE

Figure 95. — Paguristes spinipes Milne Edwards. A, an-
terior part of body in dorsal view, approximately X 4
(after Benedict, 1901) ; B, right chela, outer surface,
5 mm. indicated.

siderably exceeding rather obtuse lateral projec-
tions. Eyestalks considerably longer than greatest
width of front but not quite so long as length of
anterior shield, somewhat contracted in middle
and slightly bent laterally, not much dilated
distally; eye scales acuminate. Antennular pe-
duncles extending to tips of, or a little beyond,
eyestalks. Antennal peduncles extending about
two-thirds length of eyestalks; acicles straight,
terminated by a spiny fork, and with two or
three spines on internal and external borders.

Chelipeds subequal and similar in form, narrow
but massive; hands less than half as broad as
long; upper surface of hands and carpi covered
with conical spines, many with corneous tips,
strongest on superointernal border; fingers more
than half as long as whole of propodus and ter-
minating in corneous tips, opposed edges with
numerous teeth. Walking legs extending a little
beyond chelipeds, ornamented with tufts of hair
most numerous and rigid on dactyls; dactyls
regularly curved and half again as long as pro-

podus; crest of spines on carpus and propodus
extending along a portion of dactyl of first walk-
ing legs, but reduced, and present on carpus only
of second walking legs.

Measurements. — Length of carapace : adults, 17
mm.; immatures, approximately 5 mm. (Milne
Edwards and Bouvier, 1893, in part).

Variations. — The eyestalks are somewhat
shorter than the front in young individuals but
much longer in adults'; they are frequently un-
equal in length. The cardiac region is calcified
but the areas lateral to it are variably calcified
(Milne Edwards and Bouvier, 1893).

Color. — A spot of orange red on external and
internal faces of first walking legs, less definite
on two following pairs; occasionally, traces of
red coloration on anterior part of cephalothorax
(Milne Edwards and Bouvier, 1893). In alcohol,
nearly white, each cheliped with a conspicuous
orange-yellow band across merus and a faint trace
of a similar band on each walking leg (Hay and
Shore, 1918).

Habitat. — This essentially deep-water hermit
has been taken from shells of Cassis and Xeno-
phora; 73 to 350 fathoms.

Type locality. — Grenada, 92 fathoms.

Known range. — Gulf Stream south of Cape
Lookout, N.C., off Cape Canaveral and Sarasota,
Fla. ; Barbados to Pernambuco, Brazil.

Remarks. — This species has rarely been col-
lected north of Barbados.

Paguristes tortugae Schmitt

Figure 96
Paguristes tortugae Schmitt, 1933, p. 7, fig. 4. — Provenzano,
1959, p. 388, fig. 11 (rev.).

Recognition characters. — Anterior shield of
carapace longer than broad; rostrum triangular,
in advance of lateral projections of front. Eye-
stalks slender, straight, as long as greatest width
of anterior shield; eye scales separated by ros-
trum, anterior process armed with three or four
spines (occasionally two) decreasing in size from
median spine outward. Antennular peduncles
reaching to base of cornea or slightly beyond.
Antennal peduncles reaching to three-fourths
length of eyestalks; flagella not reaching to tips
of chelipeds, sparsely setose; acicles obscured by
hairs, armed with two spines on inner edge and
at least three on outer edge.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

119

Figure 96. — Paguristes tortugae Schniitt.
Anterior part of body in dorsal view,
X 10 (after Holthuis, 1959).

Chelipeds equal, thickly covered with hairs,
medial margins of chelae and carpi straight,
fitting closely together when retracted; hands
with forwardly directed, hooked spines on median
upper surface, inner margin, outer half, and outer
margin of immovable finger, hairs arising along
anterior part of base of tubercles giving a squa-
mose appearance; dactyl with seven more or less
distinct, transverse rows of small, horny-tipped
tubercles, largest on upper margin; fingers with
tips corneous, more or less spooned; lower surface
of chela smooth except for some tufts of hairs.
First and second walking legs with heavy fringes
of hairs along upper and lower margins and some
tufts on lateral surfaces, outer surface smooth;

dactyls somewhat longer than propodi, tips dark,
corneous, a row of similar colored spinules on
ventral border; inner surface of dactyls and
propodi with squamiform tubercles near upper
and lower margins, more pronounced where bases
of hairs coincide with squamous tubercles. First
walking legs with upper surface of propodus
serrate, and a few denticles at base of dactyl. Sec-
ond legs with two rows of spines on carpus, one
on upper margin and one on upper portion of
inner surface, a shallow groove on upper part of
inner surface extending distad from carpus. Third
legs with a single row of spines on carpus ; merus
of second and third legs with an anteroventral
spine.

Measurements. — Length of carapace: male, 10
mm.; ovigerous female, 7 mm. (Provenzano,
1959).

Variations. — Holthuis (1959) described a some-
what longer rostrum, a longer antennular pe-
duncle, a somewhat spinier acicle, and a less
spiny merus on the cheliped for Surinam speci-
mens.

Color. — Whitish, with large spines on inner
margin of hand and carpus red; occasionally,
hard parts lightly tinted with green or purple;
eyestalks with a single band of black on white,
and antennules with similar rings on ends of ar-
ticles (Provenzano, 1959). In preserved material,
these dark bands appear red (Holthuis, 1959).

Habitat. — Usually taken on hard or shelly
bottom; shallow water to 20 fathoms.

Type locality. — Off Fort Jefferson Dock, Gar-
den Key, Dry Tortugas, Fla.

Known range. — Reefs off Beaufort, N.C., to
southern Florida; through West Indies to
Surinam.

Remarks. — Ovigerous females have been re-
ported from February to October in Florida
(Provenzano, 1959, in part), in June in North
Carolina, August in South Carolina, October in
Puerto Rico, and in May from Surinam
(Holthius, 1959).

Genus Clibanarius Dana, 1852

Dana. 1852, p. 6.

Clibanarius vittatus (Bosc). Striped hermit crab

Figure 97

Pagurus vittatus Bosc, [1801 or 1802], p. 78, pi. 12, flg. 1.
Clibanarius vittatus: Hay and Shore, 1918, p. 410, pi. 30,
flg. 9.— Provenzano, 1959, p. 371, flg. 5 D.

120

FISH AND WILDLIFE SERVICE

Figitbe 97. — Clibarvarins vittatus (Bosc). A, anterior part of body in dorsal
view, X 1.6; B, third leg, X 3.2 (after Holthuis, 1959).

Recognition characters. — Anterior shield of
carapace subquadrate, a few fine hairs along
lateral margin. Front with rostrum acute, tri-
angular, slightly more prominent than lateral
projections. Eyestalks almost as long as width of
anterior shield, nearly cylindrical, cornea not
dilated, right eyestalk occasionally slightly
shorter than left; eye scales narrow, approxi-
mated at tips, but well separated at bases, margin
with one to four spines, terminal largest. Anten-
nular peduncles as long as eyestalks. Antennal
peduncles reaching to at least three-fourths length
of eyestalks; acicles acute, with three to five ter-
minal spines, flagella reaching tips of walking
legs.

Chelipeds equal, sparsely hairy; hands thick,
inflated, twice as long as broad, covered thickly
above, sparingly below, with somewhat blunted
spines darker than color of hands and with
bundles of stiff hairs springing from bases; fin-
gers opening horizontally, heavy, toothed and
somewhat gaping at base, cutting edges corneous,
extending along upper side; carpus as long as

palm. First and second walking legs exceeding
chelipeds by over half length of dactyls, tips
corneous; two distal articles with numerous
bundles of hairs. Third and fourth walking legs
reduced; third subchelate; fourth very small,
chelate, and turned on back.

Measurements. — Length of carapace: male, 32
mm. ; female, 29 mm.

Color. — Greenish to dark brown with longi-
tudinal stripes of gray to white; antennular pe-
duncles light above, dark laterally, with orange
flagella ; propodus of walking legs with four pairs
of light, longitudinal stripes continuous with
similar stripes on dactyl and carpus, one of ven-
tral stripes usually somewhat diffuse (Proven-
zano, 1959).

Habitat. — Common on harbor beaches, espe-
cially on borders of mud flats (Pearse, Humm,
and Wharton, 1942) ; often on rock jetties or high
on bay shores (Whitten, Rosene, and Hedgpeth,
1950) ; waterline to a few feet.

Type locality. — Coasts of Carolina.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

121

Known range. — Potomac River, Gunston, Va.,
to Rio de Janeiro, Brazil.

Remarks. — This large species is one of the com-
monest conspicuous hermit crabs of the shore
region of the Carolina bays. It has a broad range
along the western Atlantic, and Holthuis (1959)
has given new distribution records, as well as a
history of its early recognition in this hemisphere.

Ovigerous females have been reported from
Surinam in July and August (Holthuis, 1959)
and from Florida in October (Provenzano, 1959).

Genus Petrochirus Stimpson, 1858

Stlmpson, 1858, p. 233 (71).

Petrochirus diogenes (Linnaeus)
Figure 98

Cancer Diogenes Linnaeus. 1758. p. 631.

Petrochirus bahamensis: Hay and Shore, 1918, p. 410, pi. 30,
fig. 6.— Schmitt, 1935a, p. 206, fig. 66.— Provenzano, 1959, p. 378,
fig. 8.— 1961, p. 153 (rev.).

Petrochirus diogenes: .Holthuis, 1959, p. 151 (rev.).

Recognition characters. — Anterior shield of
carapace flattened, as broad as long, rough, un-
even, and with scattered tufts of hairs ; front tri-
lobate, rostrum about as long as lateral projec-
tions. Eyestalks straight, dilated distally, with a
tuft of hair above corneal surfaces and scanty
tufts near base; eye scales broad basally, acute
anteriorly with indistinct serrations. Antennular
peduncles reaching or exceeding eyestalks. Anten-
nal peduncles shorter than eyestalks; acicles
slender, hairy, and minutely spined.

Chelipeds massive, subequal, right slightly
larger; hands and carpi coarsely roughened with
grouped tubercles separated by appressed setae on
upper and, to some extent, lower surfaces, becom-
ing spinose along inner margin; fingers opening
obliquely, major chela with fingers tuberculate on
crushing edges, minor chela with fingers some-
what spooned, cutting edges sharp, tips corneous.
First two pairs of walking legs with carpus
ornamented above like chelae; propodi similar
with clusters of hairs beneath; dactyls with
slightly twisted rows of spines and dense setae;
propodi and carpi, especially of first walking legs,
with dorsal row of dark-tipped spines. Third
legs subchelate; last legs chelate and turned up
against side.

Measurements. — Length of carapace: male, 75
mm.; female, 44 mm.

Figube 98. — Petrochirus diogenes (Linnaeus). Female in
dorsal view showing well-developed triramous pleopods,
X 0.35 (after Provenzano, 1959).

Color. — Generally reddish; chelipeds reddish
except between fingers, and white spots on carpal
articles; antennal and antennular peduncles
longitudinally striped with red and white,
antennal flagella transversely banded with red
and white (Provenzano, 1959).

Habitat. — Mud, mud and shell, and sand
bottoms. Common on shrimping grounds near
Tortugas, Fla. (Provenzano, 1959), in the western
Gulf of Mexico (Hildebrand, 1954, 1955), and on
fishing grounds southeast of Cape Lookout, N.C.,
in about 18 fathoms; to 50 fathoms (Provenzano,
1959; Holthuis, 1959).

Type locality. — Near shores of Bahama Islands
(Catesby, in Holthuis, 1959).

Known range. — Off Cape Lookout, N.C., to
Brazil; West Indies.

Remarks. — The genus Petrochirus has a fossil
record extending from the Cretaceous to the pres-

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FISH AND WILDLIFE SERVICE

ent in North America (Rathbun, 1935). Toula
(1911) considered the Miocene form from Panama
to be conspecific with the living species in the
West Indies region, but Rathbun (1918a) con-
sidered this form as distinct (P. bouvieri) and
possibly ancestral to the modern species.

Petrochirus diogenes is the largest hermit crab
in the Carolinian fauna and this feature, plus its
coarsely tuberculate, ruddy appendages, makes it
conspicuous. A common commensal is the porcel-
lanid crab, Porcellana sayana, and other com-
mensals on the shells carried by the crab, such as
Crepidula plana (Say), bryozoans (Scrupocel-
laria sp.), tubicolous worms (Hydroides sp. and
Spirorbis sp.) and other species, are mentioned by
Pearse (1932b). Ovigerous females have been re-
ported in March from the Virgin Islands (Pro-
venzano, 1961).

Pearse (1932a) determined the freezing point
of P. diogenes blood (range -1.90° to -2.32° C).

Holthuis (1959) reviewed the complex nomen-
clatural history of the species, designated the type,
restricted the type locality, and delimited the
geographic range.

Genus Dardanus Paulson, 1875

Paulson, 1875, t>. 96 (translation). — Hemming,
163. — Provenzano, 1959, p. 372.

1958b, p.

KEY TO SPECIES IN THE CAROLINAS

a. Propodus of second left walking leg conspicuously
hairy, with a lateral longitudinal ridge paralleled by a
groove, ridge crossed by rugae venosus (p. 123).

aa. Propodus of second left walking leg not hairy, with-
out a lateral longitudinal ridge or groove, rugae ar-
ranged in herringbone pattern insignia (p. 124).

Dardanus venosus (H. Milne Edwards)

Figure 99

Pagurus venosus H. Milne Edwards, 1848, p. 61.
Dardanus venosus: Verrill, 1908, p. 441, text-figs. 58-59 ; pi.
26, figs. 4a, 5a. — Provenzano, 1959, p. 374, fig. 6 (rev.).

Recognition characters. — Anterior shield of
carapace slightly longer than width of front,
smooth, with few hairs and some deep lines near
sides; anterior margin with rostrum wanting,
lateral projections between bases of eyestalks and
antennae prominent. Eyestalks stout, slightly
constricted in middle, extending to tips of an-
tennal peduncles or slightly beyond, a tuft of
setae just behind cornea; eye scales widely sepa-
rated, inner margins straight, blunt tips bearing

Fioube 99. — Dardanus venosus (H. Milne Edwards). A.
anterior part of body in dorsal view showing ridge on
second left walking leg ; B, inner surface of major
chela showing "veins" which specific name describes ;
A-B approximately X 1.5 (after Provenzano, 1959).

several spines. Antennular peduncles exceeding
cornea by one-third of terminal peduncular ar-
ticle. Acicles short, reaching midlength of eye-
stalks, armed with small, sharp spines.

Chelipeds unequal, left much larger than right;
fingertips black, corneous, spooned. Major chela
with outer surface covered by scalelike tubercles
separated by fan-shaped fringes of appressed
hairs, inner surface smooth, medial margin bear-
ing row of seven sharp, horny-tipped spines con-
tinued as row of smaller spines on dactyl and as
well-developed spines on carpus; carpus with
smaller sharp spines scattered over surface. Minor
chela narrower, lacking scalelike tubercles on
outer surface, and with long setae rather than
appressed bristles. Walking legs with dactyls

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

12'

longer than propodi, longest in first pair ; second
left leg markedly different from others, with
dactyl and propodus broadened, fringed with
hairs, and with a lateral longitudinal ridge paral-
leled by a groove, ridge crossed with numerous
rugae.

Measurements. — Length of carapace (medium
sized individual) : 31 mm. (Verrill, 1908).

Color. — Walking legs with broad, transverse
bands of red; legs, fingers of hands, and inside
surfaces of chelipeds reticulated with fine red
lines (hence, descriptive specific name) ; scalelike
tubercles of hand and rugae of second left leg
blue to purple; eye scales sometimes white (Pro-
venzano, 1959).

Habitat. — Often found on sand and grass flats,
on mud bottom, and in baited traps (various
authors). Shells inhabited sometimes bear sponges
or coelenterates (Holthuis, 1959). Shallow water
near shore to 50 fathoms ; rarely to 200 fathoms.

Type locality. — Guadeloupe.

Known range. — Off Beaufort Inlet, N.C.
(Cerame- Vivas, Williams, and Gray, 1963) ;
through West Indies to northeastern Brazil;
Bermuda.

Remarks. — Ovigerous females have been re*
ported from northeastern Florida in June, from
the Virgin Islands in March and May (Pro-
venzano, 1961), and from northeastern South
America in April, May, July, and September.

Dardanus insignis (Saussure)

Figure 100

Pvgurus insignia Saussure, 1858, p. 453, pi, 3. figs, 20, 20a.
Dardanus insignis: Verrill, 1908, p. 446, text-fig. 60; pi. 26,
figs. 4 b, c, 5b.

Recognition characters. — Anterior shield of
carapace longer than width of front, with
.scattered clumps of setae, and roughened slightly
near anterior and anterolateral margins. Anterior
margin with rostrum wanting; lateral projections
on front triangular, thickened, prominent, and
hairy on frontal edge. Eyestalks stout, slightly
constricted in middle, extending almost to tips of
antennal peduncles, a pencil of hairs at base of
dilated cornea; eye scales prominent, well sepa-
rated, serrated distally with a strong medial pair
of spines separated from a smaller more lateral
series of four spines by a notch obscured by a
pencil of setae. Antennular peduncles with base
of terminal article exceeded by eyestalks. Acicles

Figure 100. — Dardanus insignis (Saussure). Anterior
part of male in dorsal view; 50 mm. indicated.

long, reaching to base of cornea, with a few spines
and hairs arranged in a spiral line originating on
inner surface at base and curving across dorsal
surface to termination on lateral surface near tip.

Chelipeds heavy, left larger than right, covered
with ciliated, tuberculate rugosities becoming
bolder and more diagonal distally on hands and
immovable fingers; movable finger of major chela
with ciliated rugosities somewhat diagonal, those
on minor dactyl irregularly arranged; opposed
edges of fingers with heavy white teeth, tips
black; spine on crest of meri, outer surface of
carpi, and hands, largest spines on upper medial
border ; a row of spines on lower medial border of
merus and ischium. First two pairs of walking
legs strong, with rugose pattern similar to
chelipeds and forming herringbone pattern on
outer surface of propodus of large second left
walking leg; dactyls of these walking legs with
crest of spines dorsally, that of second left leg
with crest of spines dorsally and vent rally, and
continued below on propodus. Third and fourth
walking legs reduced and specialized.

Measurements. — Male: length of carapace, 38
mm.; anterior shield, length, 17.5 mm., width,
15.5 mm.

Color. — Ground color yellowish; rugosities tan
near body, becoming maroon on chelipeds and

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first two pairs of walking legs distally, proximal
rugae on hands with reticulate maroon pattern on
yellowish background; anterior shield mottled
tan; eyestalks banded alternately with maroon,
yellow, and tan.

Habitat.— Fifteen to 124 fathoms.

Type locality. — Guadeloupe.

Known range. — Off Oregon Inlet, N.C., 17
fathoms (Cerame- Vivas, Williams, and Gray,
1963), to Port Aransas, Tex.; through West
Indies to Guadeloupe.

Remarks. — Until recently this species was
known only from beyond the 100-fathom curve
in the Carolinas, but it has been collected in
shallow water north of Cape Hatteras (Cerame-
Vivas, Williams, and Gray, 1963).

Subfamily Pagurinae

The chief distinguishing characters for this
group are given in the Key to Subfamilies of
Hermit Crabs.

KEY TO GENERA OF PAGURINAE IN THE
CAROLINAS

a. Fingers opening and closing horizontally ; no paired
appendages on abdomen of either sex.
b. Vas deferens of male not protruding in form of a

tube Pagurus (p. 125).

bb. Vas deferens of left side protruding, and coiled in

a spiral Spiropagurus dispar (p. 133).

aa. Fingers opening and closing obliquely ; vas deferens
of male not protruding ; a pair of appendages on first
abdominal segment of female only

Pylopagurus (p. 133).

Genus Pagurus Fabricius, 1775

Provenzano, 1959, p. 393. — Hemming, 1958b, p. 163.

KEY TO SPECIES IN THE CAROLINAS

a. Eye scales unarmed or with single subterminal spine,
b. Length of eyestalk not more than 3.5 times its
greatest width.

c. Width of major chela less than one-half length,
d. Chelipeds subcylindrical, relatively smooth on
outer surface ; eye scales somewhat rounded
distally, dorsal surface shallowly excavated

longicarpus (p. 125).
dd. Chelipeds not subcylindrical, relatively spiny
on outer surface ; eye scales rounded distally
but not excavated on dorsal surface

defensus ( p. 127 ) .

cc. Width of major chela more than one-half length,

one or both chelae broad and flattened.

d. Dactyl of major chela with sharply produced

angle on medial margin ; no depressed spot at

base of immovable finger of either chela

pollicaris (p. 128).

dd. Dactyl of major chela without sharply pro-
duced angle on medial margin ; a depressed spot
(or spots) at base of immovable fingers of chelae

impressus (p. 129).
bb. Length of eyestalk at least 4 times its greatest

width annulipes (p. 130).

aa. Eye scales armed with two or more spines.

b. Rostrum acute pygmaeus (p. 131).

'bb. Rostrum obsolete orcvidactylus (p. 132).

Pagurus longicarpus Say

Figure 101

Pagurus longicarpus Say, 1817, p. 163. — Hay and Shore, 1918,
p. 411, pi. 29, fig. 3. — Provenzano, 1959, p. 394, fig. 13 (rev.).

Fiquke 101. — Pagurus longicarpus Say. A,
anterior part of body and chelipeds in dor-
sal view ; B, second left walking leg in
lateral view ; A-B X 4 ( after Provenzano,
1959).

Recognition characters.— Anterior shield of
carapace subcordate, truncate posteriorly, about
as broad as long. Rostrum obsolete, hardly as ad-
vanced as lateral projections of front. Eyestalks
stout, 2-3 times longer than broad, much shorter
than width of anterior shield, cornea dilated ; eye
scales with concave, oval anterior lobe armed with
a subterminal spine. Antennular peduncles ex-
ceeding eyes by about half length of terminal
article. Antennal peduncles exceeding eyes by

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

125

about one-third length of last article; acicles
slender, curved sinuously outward, reaching to
tip of cornea; flagella exceeding tip of major
cheliped.

Right cheliped much larger and longer than
left, subcylindrical, devoid of hairs except for a
few short setae along inner edges of fingers;
width of hand less than one-half total length,
palm lightly crested and minutely dentate along
outer margin, upper surface minutely granulate
and with two incomplete rows of larger granules
near proximal end; fingers short, hooked at tips;
carpus as long as propodus to middle of finger,
with two rows of subspinous tubercles and
scattered smaller ones. Left cheliped smaller,
hairier, similarly formed but relatively broader;
fingers with cutting edges distally, gaping at base.
First and second walking legs with dactyls longer
than propodi, extending about as far as chelipeds.
Third and fourth pairs of legs reduced in size,
fourth turned upward on back.

Measurements. — Length of carapace: male, 10
mm.; ovigerous female, 11 mm.

Color. — Color varies with locality; specimens
of west Florida are lighter than those of east
coast ; upper surface of chelipeds and all walking
legs iridescent ; posterior carapace light green ;
hand white with median diffused pigment stripe,
carpus with dorsal stripe and one on each side;
walking legs with dactyl unstriped, propodus
with lateral stripe, merus with single lateral
muddy brown stripe and transverse stripe from
lower anterior margin to broad pigmented area on
upper surface; antennae with dark bands alter-
nating with shorter white bands. Young may have
transverse band on each article of walking legs
rather than stripe; lateral stripes of major che-
liped with V-shaped appearance in dorsal view
(Provenzano, 1959, from west Florida specimen).

Habitat. — Common on harbor beaches, in har-
bor channels, and in shallow littoral on a variety
of bottoms; to 27.5 fathoms (possibly beyond).

Type locality. — "Inhabits Bay Shores" [east
coast of United States] .

Known range. — Minas Basin, Nova Scotia
(Rathbun, 1929) to northern Florida; Sanibel Is-
land, Fla., to coast of Texas (Provenzano, 1959;
Whitten, Rosene, and Hedgpeth, 1950).

Remarks. — Pagurus longicarpus is one of the
commonest decapod crustaceans in shallow water

along the coast of the Eastern United States. Like
other similarly available crustaceans, it has been
the subject of a number of ecological and physio-
logical studies, and these have been accomplished
mostly around Woods Hole, Mass. Provenzano
(1959) suggested that the Atlantic coast and Gulf
of Mexico forms, with a hiatus between their
ranges, may be subspecifically distinct.

The general habitat of P. longicarpus, sum-
marized above, has been commented upon by other
authors (Pearse, Humm, and Wharton, 1942;
Allee, 1923). Allee concluded that the ubiquity of
this hermit crab prevents it from being of aid in
distinguishing shallow-water communities. Dia-
toms, detritus, and algae make up the food of this
species (Sanders, Goudsmit, Mills, and Hampson,
1962).

The breeding season of this common form ex-
tends from early May to mid-September (Bumpus
in Sumner, Osburn, and Cole, 1913b) in Massachu-
setts, and ovigerous females have been taken in
January, March, and September in Florida
(Wass, 1955, in part). Thompson (1901, 1903)
described four zoeae, a glaucothoe, and a first
postlarval stage, as well as various adolescent
stages. He compared larval development of P.
longicarpus with that of P. annulipes and gave re-
marks on the derivation and geological age of
pagurids.

Autotomy and regeneration in this species re-
ceived attention from Morgan (1900, 1901) and
Haseman (1907), though investigations on this
subject with other species now supersede the early
studies. The first three pairs of legs have a frac-
ture joint near their bases; hence, can be autot-
omized, but the last two pairs lack these and
cannot be autotomized. Injuries distal to the frac-
ture plane result in autotomy and regeneration;
those proximal to the plane do not result in autot-
omy. Injured abdominal appendages are readily
regenerated. Haseman carried this work farther,
showing that when the chelipeds were removed at
their breaking joints they differentiated from the
tip proximally, but the first two pairs of clawed
(walking?) legs differentiated from the base to-
ward the tip. Direction of differentiation in the
cheliped can be reversed by injuring the develop-
ing bud.

In another vein, conditioned and natural behav-
ior of P. longicarpus has been the subject of a few

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FISH AND WILDLIFE SERVICE

studies. Spaulding (1904) found the crab able to
profit by experience in vision and taste experi-
ments, and able to learn faster than P. poUicaris.
Fink (1941) was able to demonstrate decondition-
ing of fear-reflex activity over a period of 18 days,
the older crabs responding more slowly than
young ones. Allee and Douglis (1945) found that
a shell-less P. longicarpus would not feed, but if
it were given a shell to occupy it would feed nor-
mally. Crabs in shells fight for food, the larger
often fending smaller ones from a food supply.
Movement from small to larger shells is accom-
plished only after several trials and thorough
investigations of new shells, but shell-less crabs
will accept almost any shape of shell in any condi-
tion. Shell-less crabs placed in a finger bowl tend
to fight continuously until one or both are dead,
usually within 24 hours. If an empty shell is
dropped into a container with two shell-less crabs,
one will immediately enter the shell. If the larger
individual does not enter first, it will extract the
smaller forcibly and enter in its place. Shell-less
crabs will attack housed individuals regardless of
size, but attackers were never seen to be successful
when the two combatants were of equal size or
when the housed individual was the larger.

Kropp and Perkins (1933) showed that in P.
longicarpus and other remotely related decapods
the chromatophore activity substance in the eye-
stalk will induce contraction of chromatophores
in other species, and postulated that the substance
is genetically similar throughout the group.

Finally, Keinhard (1944, 1945) and Reinhard
and Buckeridge (1950) discussed parasitism in P.
longicarpus. An examination of 8,000 crabs
showed a 1-percent infestation with a larval
acanthocephalid belonging to the genus Poly-
morphus. The worm was found in the abdominal
cavity(?) usually attached to the hind gut or
sometimes among tubules of the hepato-pancreas.
The usual number of cysts per host was one,
though as many as three occurred. Reinhard also
described an entoniscid isopod, Paguritherium
(datum, from this species. Entering the crab's
body through the dorsal side of the eyestalk, and
remaining in contact with this point of entry, the
parasite elongates with but little damage to tho-
racic organs, but becomes greatly distended in the
abdominal region. There it restricts the hepato-
pancreas and nearly obliterates the gonads as it

grows. Infestation does not externally modify the
male host. In females, the parasite reduces size of
the first three pleopods, especially length of the
endopod, and causes partial or complete loss of
ovigerous hairs on the external surface of the
endopod and protopod. Thus, secondary sexual
characters of the female crab are altered. One
percent of the crabs investigated were infested
with this parasite.

Pagurus defensus (Benedict)

Figure 102
Eupagurus defensus Benedict, 1892, p. 7.

Figure 102. — Pagurus defensus (Benedict). A, anterior
part of female in dorsal view ; B, right chela, outer
surface ; 3 mm. indicated.

Recognition characters. — Anterior portion of
carapace broader than long, subcordate. Rostral
projection broadly rounded, lateral processes tri-
angular, armed at apex with a short spine. Eye-
stalks stout, much dilated and flattened distally;
eye scales broad, rounded, anterior margin forming
a semicircle, armed with a subterminal spine.
Antennular peduncles extending beyond eyestalks
by two-thirds or more length of terminal article.
Antennal peduncle extending beyond eyestalks by
one-half length of terminal article; acicle curving
outward and extending somewhat beyond eye-
stalk.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

127

Chelipeds unequal, right larger than left. Ma-
jor chela a little wider than carpus, fingers agape,
margins set with comb of long, slender spines;
upper surface with more or less diagonal rows of
spines on palm and spines irregularly but closely
set near base of dactyl and on immovable finger ;
dactyl with several rows of irregularly placed
plates, and a small spine arising from center of
each ; carpus with three rows of sharp spines, one
on outer margin, one on upper surface, and one
on inner surface. Minor chela extending to base
of major dactyl; hand armed with spines as in
opposite member but hairier, and no spine-bearing
plates on dactyl; fingers agape; carpus with a
double crest of spines, outer margin convex, inner
margin straight and flat; merus compressed.
Walking legs long and slender, dactyls lightly
setose, longer than preceding two articles to-
gether; propodus and carpus with a crest of
spines.

Measurements. — Length of carapace : female, 7
mm.

Variations.- — Fingers of the chelae do not gape
in small individuals.

Habitat. — Sixteen to 49 fathoms.

Type locality. — Gulf of Mexico between Delta
of Mississippi River and Cedar Keys, Fla., 30
fathoms.

Known range. — Cape Hatteras to Cape Look-
out, N.C. ; Tortugas, Fla., to Alabama.

Pagurus pollicaris Say

Figure 103

Pagurug pollicaris Say, 1817, p. 162. — Hay and Shore, 1918,
p. 411, pi. 30, fig. 1. — Provenzano, 1959, p. 401, fig. 16 (rev.).

Recognition characters. — Anterior shield of
carapace subcordate, nearly as long as broad,
truncate posteriorly. Rostrum slightly less ad-
vanced than lateral projections of front. Eye-
stalks moderately stout, not so long as width of
anterior carapace, nearly straight, cornea dilated;
eye scales with round-tipped, slightly concave an-
terior lobe armed with inferior subterminal spine.
Antennular peduncles exceeding eyestalks by ap-
proximately half length of last article. Antennal
peduncles exceeding eyestalks; acicles slender,
curved outward, reaching to or beyond base of
cornea, hairy medially.

Chelipeds unequal, right much larger than left,
both covered with small, closely spaced granules,
outer margins with enlarged granules or small

Figure 103. — Pagurus pollicaris Say. Anterior part of
animal and chelipeds in dorsal view, approximately
X 3 (after Provenzano, 1959).

spines. Major chela stout, hand flattened; mov-
able finger with prominent, projecting angle on
medial border; tips of fingers acuminate; carpus
with numerous tubercles, larger than on hand,
subspinose and ciliated on upper surface; merus
with a few squamiform tubercles. Minor chela
with inner border dentate, movable finger not pro-
duced, dentation of inner border continued on
inner dorsal border of carpus. First and second
walking legs with dactyls much longer than
propodi ; first pair with small, well-defined spines
along upper margin of propodus and carpus; sec-
ond pair with spines reduced. Third legs re-
duced, fourth pair reduced and carried on back.

Measurements. — Length of carapace: male, 31
mm. ; female, 27 mm.

Color. — Color varies with locality, those of west
Florida being lighter than those of Northeastern
States. Chelipeds basically white with gray mar-
gins on insides, tips of dactyls and dark area in

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FISH AND WILDLIFE SERVICE

center of upper surface of each cheliped; re-
mainder of body light gray-tan; eyestalks brown
below cornea; hairs on antennules rusty brown
(Provenzano, 1959, for west Florida form).

Habitat. — Deep channels of harbors and littoral
waters; also found in shallow estuaries near
ocean; near low-tide mark to 25 fathoms.

Type locality. — [East] coast of United States.

Known range. — Vineyard Sound, Mass., to
northeastern Florida; Key West, Fla., to Texas
(Provenzano, 1959).

Remarks. — Blake (1953) reported P. poUicaris
from the Pleistocene of Maryland.

Ovigerous females have been reported in March
from Florida (Provenzano, 1959). They have
been found in January and November in North
Carolina, and in April in Chesapeake Bay.

Pagurus impressus (Benedict)

Figure 104

Eupagurus impressus Bendtct,,1892, p. 5.

Pagurus impressus: Provenzano, 1959, p. 399, fig. 15 (rev.).

Recognition characters. — Anterior shield of
carapace about as broad as long, flattened. Ros-
trum much rounded, in line with somewhat more
angular lateral projections of front. Eyestalks
slender, about three times longer than greatest
width, cornea dilated and flattened ; eye scales with
moderately slender, acuminate, slightly excavated
anterior lobe, subterminal spine large. Antennular
peduncles exceeding eyestalks by at least half of
last article. Antennal peduncles slightly exceed-
ing cornea ; acicles curving outward, reaching to
base of cornea, hairy on medial edge.

Chelipeds unequal, right much larger than left,
upper surfaces dented, both covered with small,
closely crowded granules, outer margins bearing
enlarged granules or small spines. Dactyl of ma-
jor cheliped with a rounded angle on medial bor-
der near tip followed by marginal spines or gran-
ules, tips of fingers acuminate; carpus with five
longitudinal rows of small spines often obscured
by irregularly arranged additional spines, a row
of well-developed spines along inner edge. Minor
cheliped reaching to angle of major dactyl; a row
of spines along inner margin of hand and carpus;
fingers somewhat spooned at tips, cutting edges
well defined, tips corneous, dactyl with medial
border tuberculate; carpus with several rows of
small spines. First and second walking legs with

Figure 104. — Pagurus impressus (Benedict). Anterior
part of body in dorsal view, approximately X 2.5 (after
Provenzano, 1959).

dactyls much longer than propodi ; first pair with
row of small, well-defined spines along upper mar-
gin of propodus and carpus; second pair with
spines reduced. Third legs reduced, fourth re-
duced and turned on back.

Measurements. — Length of carapace: male, 25
mm.; female, 16 mm. (Provenzano, 1959).

Color. — Hands solid rust to chocolate brown,
other appendages brownish with alternating thin
bands of light color; antennae, antennules, and
peduncles yellow; eyestalks brown above, bright
blue below with bright scarlet at base of eyestalks
(Provenzano, 1959).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

129

Habitat. — On sandy bottom, grassy flats, or
pilings; occasionally found in sponges (Wass,
1955) ; 6 to 18 fathoms.

Type locality. — Florida.

Known range. — Off Diamond Shoals, N.C., to
east coast of Florida ; western Florida from Sani-
bel Island north to vicinity of Alligator Harbor ;
Port Aransas, Tex.

Remarks. — Ovigerous females have been taken
in January and February in the Carolinas.

Pagurus annulipes (Stimpson)

Figure 105

Eupagurua annulipes Stimpson, 1860a, p. 243.

Pagurus annulipes: Hay and Shore, 1918, p. 412, pi. 29, flg. 12

(rev.). — -Provenzano, 1959, p. 407, flg. 18 (rev.).

Recognition characters. — Anterior shield of
carapace subcordate, scarcely longer than wide,
truncate posteriorly. Rostrum obsolete, about as
long as rounded lateral projections of front. Eye-
stalks nearly straight, shorter than front, slightly
constricted in middle, cornea not dilated; eye
scales flat, broad, and rounded but with one or
two spines on anterior border. Antennular pedun-
cles exceeding eyestalks by about one-third of last
article. Antennal peduncles reaching about to, or
beyond, tip of eyestalks; acicles slender, curving
outward, reaching about middle of last article of
antennal peduncle; flagella exceeding major che-
liped.

Chelipeds unequal, right much larger than left.
Major cheliped long, subcylindrical, moderately
and evenly granulate and ciliate above, except
subspinose in large individuals; tips of fingers
hooked, dactyl less than one-half length of hand;
carpus nearly twice as long as broad, spinulose
along inner margin. Minor cheliped much shorter,
compressed, thickly ciliate and spinulose above;
hand slightly shorter than carpus; fingers shorter
than palm, with cutting edges distally, gaping at
base. First and second walking legs with dactyls
longer than propodi, legs slender, compressed;
carpus with a distal spine on upper border. Third
legs much reduced; fourth pair smaller, turned
on back.

Measurements. — Length of carapace: male, 5
mm.; female, 4 mm. (Provenzano, 1959); Wass
(1955) found a specimen with a carapace length
of 7 mm.

Variations. — This is a small species. Males tend
to attain larger sizes than females, and this is

Figure 105. — Pagurus annulipes (Stimpson). A, anterior
part of body and chelipeds in dorsal view; B, second
left walking leg showing characteristic color bands in
lateral view; A-B approximately X 7 (after Proven-
zano, 1959).

accompanied by a proportionately larger cheliped
(Provenzano, 1959).

Color. — White to gray with brown pigment
band around each article of walking legs; an-
tennae with broad purple bands alternating with
narrower white bands, occasionally with poorly
defined longitudinal stripes on legs (Provenzano,
1959).

Habitat. — Fairly common on a variety of bot-
tom types in Massachusetts, but not so common in
the Beaufort Harbor area of North Carolina;
abundant in Thalassia beds in southern Florida,
seemingly preferring soft, sandy bottom to other

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FISH AND WILDLIFE SERVICE

types; tolerates somewhat lowered salinities of
estuaries; near low-tide mark to 23 fathoms
(Schmitt, 1935a).

Type locality. — Beaufort Harbor, N.C.

Known range. — Vineyard Sound, Mass., around
Florida peninsula to Alligator Harbor; Cuba;
Puerto Rico.

Remarks. — Ovigerous females have been re-
ported in September from Massachusetts (Thomp-
son, 1903), and from February to April, and Au-
gust to September in Florida (Provenzano, 1959).
Thompson described four zoeal, a glaucothoe, a
postlarval, and a number of adolescent stages at
Woods Hole. The only difference he found be-
tween P. annulipes and P. longicarpus in larval
development was the slightly smaller size of the
former.

Pagurus annulipes may occur a few miles off-
shore, for it has been found in the stomachs of
flounders {Paralichthys dentatus) taken 15 miles
east-southeast of Oregon Inlet, N.C, in 20-fathom
water along with numerous juvenile Cancer irro-
ratus.

Pagurus pygmaeus (Bouvier)

Figure 106

Eupagurus pygmaeus Bouvier, 1918, p. 11, fig. 4.
Pagurus pygmaeus: Provenzano, 1959, p. 410, fig. 19.

Recognition characters. — Anterior shield of
carapace longer than wide. Rostrum acute, slightly
in advance of lateral projections, each bearing a
terminal spine. Eyestalks shorter than width of
anterior carapace, wide at base, tapering toward
cornea; eye scales armed along medial margin
with four or five spines. Antennular and anten-
nal peduncles extending slightly beyond cornea;
unarmed acicle reaching base of cornea.

Chelipeds unequal, right much larger than left,
both with long but very fine hairs and forward-
projecting spines. Major chela suboval, margin
armed with strong spines, upper surface covered
with smaller, nearly blunt spines; carpus with
six very sharp spines on upper anteromedial sur-
face, two additional spines more laterally placed,
and a short row of spines along lateral margin.
Minor chela much reduced, twice longer than
broad, upper surface with many blunt spines,
some forming two central rows; tips of fingers
corneous, spooned; carpus with double row of
large spines on upper surface. Walking legs with

Figure 106. — Pagurus pygmaeus (Bouvier). A, an-
terior part of body and chelipeds in dorsal view ; B,
second left walking leg in lateral view ; C, telson ;
A-0 X 9 (after Provenzano, 1959).

dactyls shorter than propodi, approximately five
ventrally placed spines in addition to terminal
point, propodus with about seven less conspicuous
spines, all articles with long sparse setae.

Measurements. — Length of carapace: male, 3
mm.

Habitat. — Shallow water to 45 fathoms.

Type locality. — "La baie de la Zocappa," near
Santiago, Cuba.

Known range. — Off Little River, South Caro-
lina; southern Florida to Puerto Rico.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

131

Remarks. — The occurrence of this species in the
Carolinas is open to question because identifica-
tion of the South Carolina material is not certain.
Nevertheless, the species is included here. The
South Carolina specimens were ovigerous females
taken in August.

Pagurus brevidactylus (Stimpson)

Figure 107

Eupagurus brevidactylus Stimpson, 1859, p. 91.

Pagurus brevidactylus: Provenzano, 1959, p. 413, fig. 20 (rev.).

PtoTTRE 107. — Pagurus brevidactylus (Stimpson). A,
anterior part of body and chelipeds, male in dorsal
view; B, chelae of female in dorsal outline; C, second
left walking leg in lateral view ; D, telson ; A-D ap-
proximately X 6 (after Provenzano, 1959).

Recognition characters. — Anterior shield of
carapace slightly longer than broad. Rostrum ob-
solete and about on line with triangular lateral

projections. Eyestalks swollen at base, tapering
toward cornea; eye scales armed along anterior
border with three to six spines. Antennular pe-
duncles reaching at least to tips of eyestalks. An-
tennal peduncles slightly exceeding eyestalks;
acicles reaching to base of cornea or slightly be-
yond.

Chelipeds unequal in males, right larger than
left, equal or subequal in females; finger tips
corneous, spooned. Hands covered with fine hairs,
outer margin edged with spines, upper surface
with smaller spines in several rows; carpi with
strong spines above. Walking legs with long, fine,
inconspicuous hairs ; dactyls shorter than propodi
and with five to eight conspicuous spines along
inferior margin; propodi with only one or two
inconspicuous spinules along inferior margin.

Measurements. — Length of carapace: male, 3
mm. ; female, 4 mm.

Color. — Walking legs each characteristically
colored with six rust-red, or maroon stripes on
propodus, carpus, and merus, fewer on dactyl;
stripes longitudinal and interrupted at. ends of
each article ; ground color of walking legs yellow ;
hands brown with almost white fingers, not
striped ; carapace with scattering of red and white
pigment in fresh specimens (Provenzano, 1959).

Habitat. — The species seems to prefer hard bot-
tom in areas where water circulation is fairly
good (Provenzano, 1959) ; has been taken from the
Black Rocks in North Carolina; 1 to 125 fathoms.

Type locality. — Barbados.

Known range. — Off New River, N.C.; south-
western Florida from Anclote section southward ;
through West Indies to Barbados.

Remarks.- — Provenzano (1959) called attention
to the sexual dimorphism in this species. In fe-
males the hands are nearly the same size and the
right hand is spooned and serrate along the inside
margin of the fingers, whereas in males the right
hand is not only the larger, but the finger tips
appear more acuminate and the opposing mar-
gins of the fingers each bear a tooth. The speci-
mens listed by Pearse and Williams (1951) as
P. bonairensis are P. brevidactylus (U.S. National
Museum notes).

Ovigerous females have been collected from
June to August in North Carolina, March to Au-
gust in Florida, and in April in Cuba.

132

FISH AND WILDLIFE SERVICE

Genus Spiropagurus Stimpson, 1858

Stlmpson, 1858, p. 236. — Milne Edwards and Bouvier, 1893,
p. 110.— Alcock, 1905, p. 117.

Spiropagurus dispar Stimpson

Figure 108

Spiropagurus ditpar Stimpson, 1858, p. 236 [nomen nudum]. —
1859, p. 88. — Provenzano, 1961, p. 165.

Figure 108. — Spiropagurus dispar Stimpson. A, anterior
part of body in dorsal view ; B, right chela, outer sur-
face ; 2 mm. indicated.

Recognition characters. — Carapace smooth but
with hairy tracts on subcordate anterior shield
and especially on anterior portion of membranous
branchial areas; anterior margin with broadly
rounded rostrum and equally advanced, acute
lateral projections. Eyestalks more than twice as
long as basal width, slightly exceeding proximal
end of terminal articles of antennal and antennu-
lar peduncles, much dilated distally, cornea large;
eye scales triangular, with abruptly narrowed
acute tip directed slightly laterad, and slightly ex-
ceeded by strong subterminal spine. Acicles slen-
der, longer than eyestalks.

Chelipeds elongate, setiferous, right chela
larger than left. Major cheliped with fingers one-
third to one-half length of palm, cutting edges of
fingers toothed; palm ornamented with a dorsal,

submarginal row of distinct spines on each side;
carpus shorter than palm with scattered spines
dorsally; merus with a single spine on internal
anterior border, and a short row of spines on
corresponding external border. Minor cheliped
similar but narrower; palm less spiny, and fingers
with a row of fine denticles on opposed edges.
Anterior two pairs of walking legs elongate,
slender distally, somewhat less pubescent than
chelipeds; dactyls not dilated noticeably at base;
carpi with a low crest of spines.

Left vas deferens of male prominent and coiled
in a loose spiral.

Measurements. — Length of carapace: male, 5
mm.

Color. — Anterior carapace with three pairs of
pigment spots, anterolateral vertical flaps light
brown with a large, clear or colorless spot ; cornea
deep brown, eyestalks brown dorsally and ringed
with brown near base; a narrow brown-orange
ring at middle of fingers and at edge of immov-
able finger, hands reticulated with brown on up-
per surface; walking legs with a broad brown
band on dactyls; propodi with a dorsal and ven-
tral brown patch, a faint longitudinal lateral
stripe, and a pair of dorsomedial brown patches;
carpi with three faint stripes laterally (Proven-
zano, 1961, from specimen preserved in formalin).

Habitat. — The species has been found housed in
Natica canrena Linne; 5 to 100 fathoms.

Type locality. — Barbados.

Known range. — Off South Carolina ; Virgin Is-
lands; Barbados.

Remarks. — Ovigerous females have been taken
from the Virgin Islands in April and September
(Provenzano, 1961).

Genus Pylopagurus Milne Edwards and Bou-
vier, 1893

Milne Edwards and Bouvier, 1893, p. 74.

KEY TO SPECIES IN THE CAROLINAS

a. Large chela almost smooth on upper surface, border
finely crenulate; abdomen straight- -discoidalis (p. 134).
aa. Large chela more or less tuberculate on upper sur-
face, border definitely toothed ; abdomen coiled,
b. Outer surface of chelae nearly flat, not conspicu-
ously tuberculate ; rostrum exceeding unarmed lateral

projections of front corallinus (p. 134).

bb. Outer surface of chelae conspicuously convex, con-
spicuously tuberculate ; rostrum about equal to
prominent minutely armed lateral projections of
front rosaceus (p. 135).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
703-049 0—65 10

133

Pylopagurus discoidalis (Milne Edwards)

Figure 109

Eupagurus discoidalis Milne Edwards, 1880, p. 41.
Pylopagurus discoidalis: Milne Edwards and Bouvier, 1893,
p. 76, pi. 6, figs. 7-14,.

Figure 109. — Pylopagurus discoidalis (Milne Edwards).
A, anterior part of ovigerous female in dorsal view,
eyestalks showing color pattern ; B, right (major) chela
of ovigerous female, upper surface showing color pat-
tern ; 2 mm. indicated.

Recognition characters. — Anterior shield of
carapace strongly calcined, subcordate, truncate
posteriorly; anterior margin with large, sharp-
poihted rostrum extending beyond middle of eye
scales; lateral projections low and rounded, bor-
ders lateral to them very oblique. Eyestalks short,
thick, widest distally, much shorter than length of
frontal border, slightly exceeding acicles but not
reaching middle of terminal article of antennular
and antennal peduncles, cornea large; eye scales
narrow, lanceolate. Acicles without spines and
deflected somewhat outward.

Chelipeds unequal, right larger than left. Major
chela in form of operculum adapted to close open-
ings in Dentaliwm shells or similar tubes. Chela
flexing at right angle on carpus and incapable of
complete extension; upper surface smooth, flat-
tened, or slightly excavated, nearly discoidal in
outline, surrounded by a raised, finely crenulate

border; lower surface slightly wrinkled with
lines; fingers compressed, internal border of dac-
tyl with rounded tubercles; carpus short, dilated
in front, external surface ornamented with granu-
lations following feebly squamose, irregular lines
(occurring also on hand, back of edge forming
operculiform portion), and with a few denticles
on anterior border. Minor cheliped shorter than
right one; chela oval, with very fine denticles on
external border; fingers agape at base, and ter-
minating in corneous tips; carpus with some
spines on crest. Walking legs reaching tip of
major chela, dactyls lanceolate with corneous ter-
minal claw well developed.

Measurements. — Length of carapace: male,
11 mm. ; female, 10 mm. ; sexual maturity attained
at cephalothorax length of 4-5 mm.

Variations. — The large chelae become more dis-
coidal with advancing age (Milne Edwards and
Bouvier, 1893).

Color. — Whitish but with large areas of red-
dish on hands, on each article of legs, and a ring
of same color near base of eye ; reddish color may
extend over anterior portion of cephalothorax
(Milne Edwards and Bouvier, 1893).

Habitat. — The species has been taken from Den-
talium shells and from annelid tubes of similar
shape; 30 to 508 fathoms.

Type locality. — Montserrat, 120 fathoms.

Known range. — Off North Carolina capes,
through eastern Gulf of Mexico and West Indies
to mouth of Amazon Kiver, Brazil (Provenzano,
1963).

Remarks. — Ovigerous females have been re-
corded in November from southern Florida and
Brazil.

Pylopagurus corallinus (Benedict)

Figure 110

Eupagurus corallinus Benedict, 1892, p. 23.

Pagurus corallinus: Hay and Shore, 1918, p. 412, pi. 30, fig. 4.

Recognition characters. — Anterior shield of
carapace subcordate, truncate posteriorly. Ros-
trum obtuse, produced beyond rounded, unarmed,
lateral projections of front. Eyestalks stout, fall-
ing far short of tip of antennular peduncle, larg-
est distally, cornea dilated; eye scales sharp
pointed, and witli a prominent subterminal spine.
Antennal peduncle nearly as long as that of an-
tennule; acicle reaching nearly to tip of cornea.

134

FISH AND WILDLIFE SERVICE

Figure 110. — Pylopagurus corallinus (Benedict). A, an-
terior part of body in dorsal view ; B, right chela, outer
surface; (from two specimens) 3 mm. indicated.

Chelipeds unequal, right larger than left. Up-
per surface of major chela flattened or slightly
excavated, covered with small, slender spines be-
coming flattened and mushroom-shaped on im-
movable finger; hand fringed with spines, often
alternately large and small, becoming longer near
tips of fingers, inner surface with spinose tuber-
cles between base of dactyl and recess receiving
carpus, recess bounded by crest; carpus approxi-
mately as long as palm, upper surface thickly set
with sharp, spiny granules, margin with rows of
small spines; merus compressed, quadrilateral
when viewed laterally. Minor chela with hand
broad, compressed ; fingers broad, gaping at base ;
carpus compressed, and surmounted by an inner
row of small and an outer row of larger spines;
merus compressed. Carpus and propodus of first
walking leg, and carpus of second, crested with
acute spines.

Measurements. — Length of carapace: male,
7 mm. ; ovigerous female, 5 mm.

Color. — Large cheliped with merus and carpus
blotched red and white; small cheliped and walk-
ing legs banded with same colors (Benedict,
1892).

Habitat. — In tunicates, stony corals, and bryo-
zoans; 21 to 56 fathoms.

Type locality.— OS Key West, Fla.

Known range. — Off Cape Lookout, N.C., to
Gulf of Mexico between Cedar Keys, Fla., and
Mississippi Delta; off Cape Catoche, Yucatan,
Mexico.

Remarks. — Ovigerous females have been taken
off South Carolina in March, and southern Flor-
ida in June.

Pylopagurus rosaceus Milne Edwards and Bouvier

Figure 111

Pylopagurus rosaceus Milne Edwards and Bouvier, 1893, p.
97, pi. 7, figs. 10-17.— Hay and Shore, 1918, p. 413, pi. 30, fig. 5.

Figure 111. — Pylopagurus rosaceus Milne Edwards and
Bouvier. A, anterior part of body in dorsal view ; B,
right chela, outer surface with detail shown only on
dactyl; (from two specimens) 3 mm. indicated.

Recognition characters. — Anterior shield of
carapace subcordate, somewhat truncate posteri-
orly ; anterior margin with three projections, ros-
trum obtuse and slightly advanced beyond strong
lateral projections, each terminating in a minute
spine; sides of dorsal surface and anterior surface
with a few tufts of setae. Eyestalks stout, con-
siderably shorter than anterior shield, distinctly
dilated distally, and with three or four pencils of
setae in line along upper surface ; eye scales acute
anteriorly, each ending in an acute, subterminal
spine. Antennal peduncle extending beyond eye,
flagellum slender and longer than body; acicle
strongly curved, reaching almost to distal edge of
cornea.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

135

Chelipeds unequal, right much larger than left.
Both chelae capable of being bent down at a right
angle to carpus to form, either singly or together,
an operculum closing orifice of cavity inhabited by
crab. Both margins of major chela, and outer
margin of minor one, armed with a row of close-
set, conical teeth; upper surface of both covered
with closely crowded, rosettelike tubercles, each
consisting of a central larger tubercle surrounded
by a number of smaller ones; inner surface of
major hand nearly smooth between base of dactyl
and recess receiving carpus. Carpus of major
cheliped with scattered sharp spines and hairs
dorsally; merus with cross striae on upper sur-
faces and with anterior edges serrated with teeth
in a single row. Minor cheliped similar but hair-
ier and with a crest of spines on carpus. Walking
legs of medium length, first and second of left-
side, and second of right side, exceeding large
chela.

Measurements. — Length of carapace: male, 9
mm. ; female, 10 mm.

Habitat. — The type was taken from an un-
known species of the molluscan genus AntiUophos
(=Phvs) ; 65 to 92 fathoms.

Type locality. — Grenada, 92 fathoms.

Known range. — South of Cape Lookout, N.C. ;
off Western Dry Rocks, Key West, Fla. ; Grenada,
and Surinam.

Remarks. — An ovigerous female has been taken
from the Surinam locality in September.

Superfamily Hippidea

Abdomen reduced in size, bent under thorax;
appendages of sixth segment not adapted for
swimming. First pair of legs simple or subche-
late, second to fourth legs with last article curved
and flattened. Rostrum small or wanting. Third
maxillipeds without epipodites.

Family Albuneidae

Carapace flattened and without wings covering
legs. First pair of legs subchelate. Third maxilli-
peds narrow. Telson not conspicuously length-
ened, almost oval.

KEY TO GENERA IN THE CAROLINAS

a. Eyestalks narrow, triangular Albunea (p. 136).

aa. Eyestalks broad, oval Lepidopa (p. 138).

Genus Albunea Fabricius, 1798

Gordon, 1938, p. 190.

KEY TO SPECIES IN THE CAROLINAS

a. Dactyl of second and third legs with blunt, rectangular
lobe at base of anterior border gibbesii (p. 136).

aa. Dactyl of second legs with asymmetrically niucronate
spur, and third legs with acute, falciform spur at base
of anterior border paretti (p. 137).

Albunea gibbesii Stimpson

Figure 112

Albunea symnista Gibbes, 1850. p. 187.

Albunea gibbesii Stimpson, 1859. p. 78, pi. 1, fig. 6. — Benedict,
1901, p. 139.— 1904, p. 625. — Hay and Shore. 1918, p. 414, pi. 30,
fig. 11— Sehmitt, 1935a, p. 208.— Gordon, 1938, fig. 3e, p. 192,
fig. 4b, p. 194.

Recognition characters. — Carapace about as
broad as long, convex from side to side, nearly
straight from front to back; front with a minute
rostrum, and at either side a strong spine followed
by 7 to 10 slender spines ; anterolateral angle with
a stout conical spine below linea anomurica project-
ing little if any beyond anterior border; posterior
margin deeply and broadly notched; dorsal sur-
face with numerous, irregular, more or less trans-
verse, impressed lines, a short ciliated one near
front, and one crossing near middle in shape of
spread M being most conspicuous.

Eyestalks narrow, triangular, cornea at tip
minute. Antennules about twice as long as cara-
pace; flagella slender and densely ciliated above
and below along inner surface, forming respira-
tory tube when approximated. Basal article of
antenna with an acute, small, lateral spine ; flagel-
lum about half as long as peduncle. First pair of
legs stout, hairy, all but distal articles inflated;
hand subchelate; inferior distal angle of propodus
produced into a spine; dactyls curved and rather
slender. Second, third, and fourth legs stout,
hairy, and with falcate dactyls; dactyl of third
leg with falciform spur at base of anterior border,
and second with similar broader spur. Fifth legs
weak, borne above others.

Second, third, and fourth abdominal segments
with expanded pleura, fifth and sixth segments
small. Female with long uniramous pleopods on
second to fifth segments. Uropods consisting of a
rather large basal article and two small falcate
blades. Telson of male triangular, of female
rounded.

Measurements. — Length of carapace: male,
16 mm. ; female, 20 mm.

136

FISH AND WILDLIFE SERVICE

Variations. — There is some individual variation
in the pattern of spines on the anterior margin of
the carapace. Spines may vary in number, be sin-
gle, or occasionally be so close together as to ap-
pear doubled.

Color. — Light brown to orange tan above, cross
striae lighter, with irregularly placed iridescent
areas ; antennules with alternating light and dark
bands ; eyestalks with a white ring behind cornea ;
underparts light (from recently preserved speci-
mens) . Light purple with whitish markings, more
or less iridescent (various authors) .

Habitat. — Sandy bottoms; extreme low-tide
mark to 35 fathoms.

Type locality. — St. Augustine, Fla. (Stimp-
son) ; Sullivans Island, S.C. (Gibbes).

Known range. — East of Cape Lookout, N.C.,
to Texas ; through West Indies to Sao Sebastiao,
Sao Paulo, Brazil.

Remarks. — Albunea gibbesii is occasionally
found on sandy shoals, especially at times of ex-
tremely low tides when heat from the sun warms
the exposed sand and drives the animals to the
surface. Occasional specimens are found by dig-
ging, and specimens have been taken in both the
Carolinas by dredging to depths of 35 fathoms.

Ovigerous females have been taken in North
Carolina in June.

Pearse, Humm, and Wharton (1942) showed
that A. gibbesii burrows backward into the sand
as do the similar highly specialized sand dwellers,
Lepidopa websteri and Emerita talpoida. These
authors stated that A. gibbesii scrapes food from
the setose antennules with the mouth parts; how-
ever, the chelate first legs and well-developed man-
dibles suggest feeding habits more like those of
Lepidopa species. The function of the antennules
as a possible feeding device was discussed by
Benedict (1904).

Albunea paretii Guerin.

Figures 112-113
Albunea oxuophthalma Leach (MS) in White, 1847b, p. 57
(nomen nudum).
Albunea paretii Gu6rln, 1853, p. 48, pi. 1, figs. 10-lOa.
Albunea paretoi: Monod, 1956, p. 37, figs. 2-9 (rev.).

Recognition characters. — Similar to A. gibbesii,
differing chiefly in characters given in key ; dactyl
of second legs with asymmetrically mucronate
spur, third legs with acute, falciform spur at base
of anterior border.

Figure 112. — Dactyls of second to fourth legs ( from right
to left); upper row, Albunea paretii Guerin; lower
row, Albunea gibbesii Stimpson (after Gordon, 1938).

Figure 113. — Albunea paretii
Guertn. Animal in dorsal view,
legs of left side not shown, 5
mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

137

Measurements. — Length of carapace : female,
20 mm.

Habitat. — Sandy bottom; low-tide mark to 21
fathoms.

Type locality. — [Uncertain], America.

Known range. — Beaufort Inlet, N.C., to Corpus
Christi, Tex. ; through West Indies to near mouth
of Amazon River, Brazil; Bermuda; Cape Verde
Islands and Senegal to Gold Coast, West Africa.

Remarks. — Monod (1956) reviewed the tangled
history of the names given this species, but
emended the specific name to conform to the name
of the donor of the type specimen, Marquis of
Pareto. Since Guerin used the spelling paretii
twice in the original description, this spelling
must be regarded not as a printer's error but as
intentional (Holthuis, personal communication).

Ovigerous females have been taken in June in
North Carolina.

Genus Lepidopa Stimpson, 1858

Stimpson, 1858. p. 230. — Holthuis, 1960a, p. 27 (rev.).

Lepidopa websteri Benedict

Figure 114

Lepidopa venusta: Kingsley, 1880, p. 410.

Lepidopa websteri Benedict, 1903, p. 892, fig. 3.— Hay and
Shore, 1918, p. 415, pi. 30, fig. 12.

Fioube 114. — Lepidopa websteri Bene-
dict. Animal in dorsal view, first to
fourth letfs of left side no) shown, 5
mm. indicated.

Recognition characters. — Carapace about as
broad as long ; front fringed with setae, produced
into a short, triangular rostrum with acuminate
tip, and to either side of it a broadly triangular
lateral projection with acuminate tip slightly
more advanced; margin between base of rostrum
and each lateral projection almost straight; an-
terolateral angle produced into a flat spine above
linea anomurica; sides sinuous and slightly con-
vergent posteriorly, folded inward ventrally over
bases of legs, more or less membranous posteri-
orly; dorsal surface crossed near front by an
impressed, ciliate band with ends directed poste-
riorly, a narrower interrupted band ending in
obliquely impressed lines crossing at about middle
of carapace ; posterior margin concave at middle.

Eyestalks irregularly oval, lamellate. Anten-
nules with peduncles exceeding eyestalks; flagella
straight, slender, nearly three times as long as
carapace, fringed with hairs, and forming a res-
piratory tube when approximated. Antennae in-
serted at extreme outer angles of front, basal
article stout; antennal scale reduced to a minute
point; flagellum stout, curved, composed of seven
short joints. First legs with broad, flat articles;
dactyl turned back on propodus to form subchela.
Second, third, and fourth legs with terminal joint
bifurcated. Fifth legs much reduced, slender, and
folded.

Abdomen short and partly flexed beneath
thorax; second, third, and fourth segments with
expanded pleura. Uropods small, with slender
basal article, and long, oval blades, their margins
and those of abdominal segments fringed with
long, silky hairs. Telson cordate.

Measurements. — Length of carapace: 12 mm.

Color. — All parts white, iridescent, with pink
being most conspicuous tint on anterior part of
carapace, and blue showing along sides, in depres-
sions of carapace, and on extremities of fifth legs;
dorsal plates of abdomen faintly pink tinged, bor-
dered by a delicate blue green ; on either side of
middorsal line, pink shading into red, and blue
becoming deeper in shade (from note by A.
Shaftsbury, U.S. National Museum records).

Habitat. — Usually found on gradually sloping
sand beaches of open ocean at or immediately be-
low low-tide mark (Pearse, Iluinin, and Wharton,
1942) ; shallow water, limits unknown.

138

FISH AND WILDLIFE SERVICE

Type locality. — Beach near Fort Macon, [Car-
teret County], N.C.

Known range. — Drum Inlet to Beaufort Inlet,
N.C.; Ship Island and Petit Bois Island, Miss.

Remarks. — Knowledge of the ecology of this
species is confined to the brief account given by
Pearse, Humm, and Wharton (1942) which in-
cluded detailed drawings of the specialized legs,
as well as a lateral view of the whole animal. The
species is highly adapted for burrowing in sand,
and is usually found in small numbers. It bur-
rows backward, and at rest lies at an angle to the
surface with the long antennules extended in the
water above. If disturbed, the animals may de-
scend several centimeters into the sand. Benedict
(1904) commented on the possible feeding func-
tion of the antennules in the genus Lepidopa. In
1903, he found setae of annelids, skin of a small
Synapta, and parts of the flagella of some small
crustaceans among stomach contents of Lepidopa
scutellata. Such finding would be in accord with
the fact that Lepidopa, like Albunea, has well-
developed mandibles (Snodgrass, 1952).

Ovigerous females have been taken in July, and
juveniles taken in plankton tows in July and
August in North Carolina.

Family Hippidae

Carapace subcylindrical, and with wings cover-
ing legs. First legs simple. Third maxillipeds
broad. Telson lengthened, lancet-shaped.

Genus Emerita Scopoli, 1777

Heegaard and Holthuis, 1960, p. 181.

KEY TO SPECIES IN THE CAROLINAS

(After Schmitt, 1935a)

a. Dactyls of first legs subacute or sharply pointed dis-
tally ; transverse rugosities more or less continuous
over dorsum and continued posteriorly to inferior mar-
gin of carapace wings benedicti (p. 130).

aa. Dactyls of first legs rounded or obtuse distally ; lat-
eral expansions or wings of carapace for greater part
smooth and punctate talpoida (p. 140).

Emerita benedicti Schmitt

Figure 115

Emerita benedicti Schmitt, 1935a, p. 215, figs. 71 a, b. — Lunz,
1939, p. 336.

Recognition characters. — Body convex, oval;
carapace firm; transverse rugosities more or less
continuous, close set, and crossing whole of dor-

Figure 115. — Dactyl and portion
of propodus of first leg; A,
Emerita benedicti Schmitt ; B,
Emerita talpoida (Say) ; 1 mm.
indicated.

sum, those on posterior part continued on wings
of carapace to inferior margin. Rostrum equi lat-
erally triangular in shape, separated by a rounded
sinus on each side from a prominent and subacute
tooth; an impressed, transverse line behind ros-
trum and a deeper, more strongly curved one far-
ther back. Posterolateral margins extending
downward to cover bases of legs; anterolateral
margins concave and subserrate.

Eyest alks long, slender ; cornea minute. Anten-
nules about three times length of eyestalks ; basal
article with flagella hairy, forming respiratory
tube when approximated. Antennae normally
held beneath third maxillipeds, nearly twice as
long as carapace when extended ; first peduncular
article short, second one largest, with outer mar-
gin produced into a strong superior, and much
longer inferior, spine, both exceeding eyestalks;
flagellum densely beset laterally with eight rows
of fringed setae, outer rows longest.

First pair of legs directed forward, articles
more or less hairy, and with impressed, inter-
rupted, transverse ciliated lines; dactyl subacute
distally; fifth article spinose distally. Second,
third, and fourth legs less strong, hairy, tips
curved and foliaceous. Fifth legs almost filamen-
tous, entirely concealed beneath abdomen.

Abdomen broadest anteriorly, narrow posteri-
orly, flexed so that telson and sixth segment lie
beneath body. Uropods turned forward, resting
along sides of proximal segments. Telson elongate,
lanceolate, margined with reflected setae above
and inflected ones on edge; base with two short,
impressed lines.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

139

Measurements. — Length of carapace: oviger-
ous female, 18 mm.

Habitat. — Shell bottom, and probably other
types (Lunz, 1939) ; to 2 fathoms.

Type locality. — Tampa Bay, Fla.

Known range. — Type locality, and Folly River
to Edisto Island, Charleston County, S.C. ; Gulf
coast of Texas.

Remarks. — Lunz (1939) reported ovigerous
females from South Carolina in June, and they
are also known from there in July.

Emerita talpoida (Say). Mole crab; sand bug

Figures 115-116

Hippa talpoida Say, 1817. p. 160.
Hippa emerita: Ortmann, 1896 (In part), p. 232.
Emerita talpoida: Hay and Shore, 191S, p. 416, pi. 30, fig. 8. —
Sehmitt, 1935a, p. 216, figs. 74 a, b. — Snodgrass, 1952.

Figure 116. — Emerita talpoida (Say).
A, animal in dorsal view, antennae
extended ; B, animal in dorsal view,
abdomen extended ; C, animal in lat-
eral view (after Snodgrass, 1952).

Recognition characters. — Body convex, oval;
carapace firm, with overlapping rugosities anteri-
orly, smoother and polished posteriorly. Anterior
margin with a small, blunt rostrum separated by
a rounded sinus on each side from a more promi-
nent and acute tooth ; an impressed, transverse
line behind rostrum, and a deeper, more strongly
curved one farther back. Posterolateral margins
extending downward to cover bases of legs; anter-
olateral margins concave and subserrate.

Eyestalks long, slender; cornea minute. Anten-
nules approximately twice length of eyestalks;

basal article with a strong, external spine; flagella
hairy, forming respiratory tube when approxi-
mated. Antennae, normally held concealed be-
neath third maxillipeds, nearly twice as long as
carapace when extended; first peduncular article
short, second one largest with outer margin pro-
duced into a strong, anteriorly directed spine
widely bifid at tip with a deep fissure below ; fla-
gellum densely beset laterally with eight rows of
fringed setae, outer rows longest. First pair of
legs directed forward, articles more or less hairy,
and with impressed, interrupted, transverse cili-
ated lines; dactyl rounded distally, fifth article
spinose distally. Second, third, and fourth legs
less strong, hairy, tips curved and foliaceous.
Fifth legs almost filamentous, entirely concealed
beneath abdomen.

Abdomen broadest anteriorly, narrow posteri-
orly; flexed so that telson and sixth segment lie
beneath body. Uropods turned forward, resting
along sides of proximal segments. Telson elon-
gate, lanceolate, margined with reflected setae
above and inflected ones on edge; base with two
short, impressed lines.

Measurements. — Length of carapace: males, 11
mm. ; females, 26 mm.

Color. — Uniform pale yellowish brown (Snod-
grass, 1952) .

Habitat. — Sandy beaches in and below surfline^
to 2 fathoms in winter.

Type locality — [East] coast of United States.

Known range. — Harwich, [Barnstable County],
Mass., to east coast of Florida ; west coast of Flor-
ida to Grand Isle, La. ; Progreso, Yucatan, Mexico
(Sehmitt, 1935a).

Remarks. — The general ecology of Emerita tal-
poida as a representative of the specialized sandy-
beach fauna has been studied by a number of
workers, especially Wharton (1942). The eggs
are bright orange when first laid and gradually
fade to a translucent dirty gray just before hatch-
ing. Wharton gave a figure of the mature sperm
cell, and Herrick (1892, pi. 25) gave figures of de-
velopmental stages in the egg. Wharton found
the breeding season in North Carolina to extend
from early June through September, and Fish
(1925) found larvae at Woods Hole, Mass., from
late July to early September. In Florida, oviger-
ous females have been found in November. The
larval stages were most completely described by

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FISH AND WILDLIFE SERVICE

Rees (1959) from rearing experiments in the labo-
ratory. Larval development lasts 28 days and
normally encompasses at least six zoeal stages.
Rees also described the megalops stage which re-
sembles the adult in shape.

Wharton found megalops in large numbers in
sand washed by waves. This stage swims with
the abdomen extended, whereas young adults
swim with the abdomen flexed. Megalops and
young adults were found to be distributed evenly
in the wave-washed zone rather than in colonies
as are adults. Wharton traced development of the
pleopods of females from the truly swimming
appendages of the megalops to the uniramous non-
swimming pleopods of adults. Adult males lack
pleopods.

The average carapace length of young adidt
females increased from 3 mm. in early summer to
8 mm. the following May, and by August had in-
creased to 18 mm. (maximum, 26 mm.). Whar-
ton thought that females have one reproductive
period in summer at an age of about 1 year, then
live a short time longer and die at an age of about
1 year and 3 months. Williams (1947), studying
size- frequency distributions, thought that they
live to be 2 years of age, and Edwards and Irving
(1943) stated that at Woods Hole females live
27 months, males 25. Since large females (to 21
mm.) can be taken in winter, the latter estimates
are more likely correct, and Wharton's 26-mm.
female was probably 2 years old.

Small males appear about the same time as
females. Sexually mature at very small sizes (car-
apace length, 3 mm.) they seek out and attach
themselves to year-old females. As many as seven
small males were found on a single large female,
and Wharton judged that they remain attached
for long periods :

The attachment of the small males to the large females
is achieved by various methods. These semiparasitic
mates have been found in the gill chambers, clamped be-
tween the coxae of the thoracic appendages, attached to
egg masses, clamped by means of their telson to the
ovigerous hairs of the pleopods, and some seen to roam
about on the ventral surface of the larger females. A few
males seemed to be attached by means of the spermato-
phores which are extruded from the basal segment of the
fifth leg ; however, these may have been merely depositing
the spermatophores.

By winter, the males are free living, and by the
following June attain a size of about 7 mm. (max-

imum, 10 mm.). Wharton thought that these die
in July after a possible second mating period.

It was estimated that growth of large females
from early June to late August may be as much as
0.08 mm. per day. However, both Wharton (1942)
and Williams (1947) noticed that there is con-
siderable annual fluctuation in size at the same
locality, and Williams further stated that there
is considerable variation in size between localities
in the same year.

The beautiful adaptations of this species for
life in the shifting sand of the surf zone were
treated by Wharton, and the anatomical speciali-
zations were exhaustively discussed by Snodgrass
(1952). Adults can swim by means of the uropods,
but they are primarily adapted for burrowing
backward into wet sand. This is accomplished by
rotating the uropods in unison, throwing sand
dorsally, moving the second, third, and fourth
legs laterally and posteriorly in unison, and by
pushing the first legs alternately laterally and
anteriorly. Once the animal is buried, the fringed
antennae are allowed to lie on the sand extended
anterolaterally to strain the receding water of
waves. Stomach contents consist of small par-
ticulate matter, but the exact method of trans-
fer of food from the antennae to the mouth is
unknown.

Emerita talpoida moves up and down the beach
with the tide, following shallow waves toward the
water or moving up the beach with deep waves.
Jones (1936) compared the habits of E. emerita
to those of E. talpoida and devised a clever
method of marking animals with string for the
purpose of tracing their movements on the beach.

Edwards and Irving (1943) studied the influ-
ence of temperature and season on oxygen con-
sumption in E. talpoida at Woods Hole. They
found that oxygen consumption of winter animals
at 12° C. is about the same as that of the smallest
summer animals at 17° C; consumption of winter
animals at 3° C. is about the same as that of sum-
mer animals at 13° C. They concluded that E.
talpoida from the Woods Hole area becomes ad-
justed to seasonal changes in temperature in such
a manner that rate of metabolism in winter is
kept at a level comparable to that in summer. This
explains why growth is imiform throughout the
year, though the animals live in 6 to 12 feet of
water in winter rather than in the surf. The
method of feeding in winter was not discussed.

MARINE DECAPOD CRUSTACEANS OF THE CAROLENTAS

141

Section Brachyura

Crabs with abdomen much reduced in size,
straight, symmetrical, closely bent under thorax,
never used for swimming, and with uropods rarely
present, never biramous. Cephalothorax de-
pressed, fused with epistome at sides and nearly
always in middle. Antennal scales immovable.
Third maxillipeds broad. First pair of legs che-
late and nearly always much stronger than other
legs.

Subsection Gymnopleura

Anterior thoracic sterna broad, posterior tho-
racic sterna narrow and keellike. Posterior tho-
racic epimera largely exposed by reduction of
branchiostegite. Female openings on coxae. Last
pair of legs dorsal in position, normal or reduced
in size. Sternal canal present. Thoracic nerve
ganglion-chain elongate. Antennary sternum tri-
angular, spout-shaped. Branchiae eight on each
side (Bourne, 1922).

Family Raninidae

Crabs with carapace remarkably elongate but
not covering abdominal terga, first four or five
terga lying exposed in dorsal plane of body. Last
pair of legs also raised in dorsal plane of body.
Antennae and antennules large, not folding into
fossettes. Vasa deferentia protruding through
bases of fifth pair of legs; oviducts piercing coxa
of third pair of legs. Sternum broad anteriorly,
narrow or linear posteriorly. A pair of respira-
tory orifices between tergum of first abdominal
segment and coxae of last pair of legs. External
maxillipeds completely covering buccal cavity,
with palp concealed in repose; exopodite but little
longer than ischium. Gills less than nine in num-
ber on either side. Hand flat, immovable finger
extremely bent allowing movable finger to close
against anterior border of hand. (Modified after
Alcock, 1896, and Rathbun, 1937.)

Genus Ranilia H. Milne Edwards, 1837

Rathbun, 1937, p. 17.

Ranilia muricata II. Milne Edwards

Figure 117

Ranilia muricata H. Milne Edwards, 1S37, p. 196.— Hay and
Shore, 1918, p. 420. pi. 31, flg. 1.— Rathbun, 1937, p. 18, pi. 3,
figs. 8-6 ; pi. 4, figs. 1-4 (rev.).

Figure 117. — Ranilia muricata H. Milne Ed-
wards. Ovigerous female in dorsal view,
first to fourth legs of right side shown, only
fifth leg of left side shown, 5 mm. indicated.

Recognition characters. — Carapace oval,
strongly convex from side to side, slightly so
from front to back, smooth posteriorly but with
numerous transverse ciliated wrinkles anteriorly.
Rostrum slender ; anterior border of carapace with
four strong spines on each side, innermost over-
hanging base of orbit, third surmounting exter-
nal angle of orbit, fourth at external angle of
front. Eyestalks strong, about four times as long
as rostrum, and capable of being turned back into
deep, oblique orbits. Antennules small. Antennae
directed forward, slightly longer than eyestalks.

First pair of legs subchelate, stout, flattened
distally, squamous-denticulate above, with a
strong spine on superodistal margin of merus,
carpus, and hand ; distal margin of hand perpen-
dicular, toothed; dactyl strong, curved. Second,
third, and fourth pairs of legs with flattened, tri-
angular dactyls. Fifth pair of legs elevated,
turned forward, fringed with hairs.

Abdomen short and narrow.

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FISH AND WILDLIFE SERVICE

Measurements. — Carapace: length, 39 mm.;
width, 28 mm.

Color. — Porcelain white with red, vermiculate,
transverse lines on cephalothorax, and red dots
and blotches on legs. Gibbes, in Rathbun (1937)
gave the color of dry specimens as purplish mixed
with yellow and orange in places, particularly
about the articulations and spines, with the latter
having white tips, and the chelipeds, walking legs,
and abdominal segments with purplish markings.

Habitat. — This species appears to be confined
to sand bottoms well offshore. Specimens have
been obtained in dredge hauls, and fragments of
others taken from fish stomachs off North Caro-
lina. The species has not been found within Beau-
fort, N.C., harbor, nor along the beaches; 7 to 56
fathoms.

Type locality. — Unknown.

Knoion range. — Off Cape Lookout, N.C., to
northwest Florida; Bahamas; Swan Island in
Caribbean Sea.

Remarks. — Though this modern species has no
fossil record in North America, the Family Ran-
inidae in this region has a fossil record dating
from the Cretaceous (Rathbun, 1935).

Rathbun (1937) reported ovigerous females in
April from Florida, and in September from North
Carolina.

Subsection Dromiacea

Carapace subglobose or subquadrate, frontal
region narrow. Last one or two pairs of legs small,
subdorsal in position. Abdomen folded under
thorax, penultimate segment usually without ap-
pendages ; five pairs of appendages in female, first
pair rudimentary. Lateral thoracic apodemata
united in common center, forming a sternal canal.
External maxillipeds with merus and ischium
subquadrate (Rathbun, 1937).

Family Dromiidae

Carapace subglobular, rarely flattened; no
lineae anomuricae (a pair of longitudinal suture
lines on carapace). Sternum of female traversed
at least in part by two obliquely longitudinal
grooves. External maxillipeds generally operculi-
form. Legs of moderate size; fourth and fifth
pairs short., subdorsal in position, furnished with
small hooklike nail or dactyl. Sixth segment of

abdomen generally with rudimentary uropods
(Schmitt, 1921).

The significance of the obliquely longitudinal
sternal grooves on the females of this family has
recently been treated by Gordon (1950). She
found these to be external evidence of a pair of
involuted tubes (variously developed in different
species) leading from an external opening at the
anterior end of the grooves posteriorly to paired
spermathecae enclosed in the endophragmal sys-
tem.

The North American fossil record for this
family dates from the lower Cretaceous of Texas
(Rathbun, 1935), though no modern species in the
Carolinian fauna possesses a known fossil record.

KEY TO GENERA IN THE CAROLINAS

a. Carapace firm and hard ; body covered with short

pubescence Dromidia (p. 143).

aa. Carapace soft and membranous ; body mostly naked

Hypoconcha (p. 144).

Genus Dromidia Stimpson, 1858

Rathbun, 1937, p. 32.

Dromidia antillensis Stimpson

Figure 118

Dromidia antillensis Stimpson, 1859, p. 71. — Hay and Shore,
1918, p. 417, pi. 31, fig. 5.— Rathbun, 1937, p. 33, text-fig. 12,
pi. 7, figs. 1-3 (rev.).

Recognition characters. — Body and legs cov-
ered with thick coat of short pubescence, leaving
only parts of fingers exposed. Carapace convex
in all directions, longer than broad ; frontal region
longitudinally grooved along middle; front
strongly deflexed, with five small, slender teeth,
median three subequal and approximately as long
as distance between them at bases, teeth over eyes
somewhat shorter but acute. Anterolateral margin
of carapace deflected toward corner of buccal
area, armed with four or five teeth.

Chelipeds rather thick and heavy; carpus den-
tate with small teeth at anterior angles; palm
shorter than dactyl and armed with three blunt
spines on upper margin; fingers curved, with
strongly interlocking teeth. Walking legs rather
slender; last pair turned forward over back, and
much longer than fourth pair; dactyls of fourth
and fifth legs hooked, closing against unequal pair
of distal spines on propodus.

Measurements. — Carapace of male: length, 32
mm. ; width, 31 mm.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

143

Figure 118. — Dromidia antillensis Stimpson. Male in
dorsal view, legs of left side not shown, 10 mm. indi-
cated.

Color. — Quite variable. General ground color
dirty yellowish green, olive buff, white, coral-mud
gray, orange buff or various shades of red with
lighter pubescence; fingers with bases darker than
white tips, shades of orange, pink, or red ; cornea
of eyes gray, hazel, reddish speckled or brown;
some specimens with bluish cast on maxillipeds
and antennular peduncles. Rathbun (1937) gave
great detail on a number of individuals which ap-
peared to vary from light to dark in a harmoni-
ous set of colors.

Habitat. — Shore to 170 fathoms.

Type localities. — St. Thomas, V.I., Key Bis-
cayne and Tortugas, Fla.

Known range. — Off Cape Hatteras, N.C.,
through Gulf of Mexico and West Indies, to State
of Bahia, Brazil ; Bermuda.

Remarks. — This species is usually found carry-
ing a covering of compound ascidians, sponge, or
zoanthoid polyps. The species is primarily south-
ern in distribution, the North Carolina records
representing marginal occurrence in a favorable
northern locality. Hildebrand (1955) found il

common on the Campeche Banks shrimping
grounds.

Rathbun (1937) reported ovigerous females
from Florida and the West Indies in winter,
spring, and summer.

Genus Hypoconcha Guerin, 1854

Rathbun. 1937, p. 44.

KEY TO SPECIES IN THE CAROLINAS

a. Anterior margin of carapace without spines

arouata (p. 144).

aa. Anterior margin of carapace with several strong

spines sabulosa (p. 145).

Hypoconcha arcuata Stimpson

Figure 119

Hypoconcha arcuata Stimpson, 1858, p. 226. — Hay and Shore,
1918, p. 418, pi. 31, fig. 2.— Rathbun, 1937, p. 47, pi. 11, figs. 1-4.

Recognition characters. — Body short, broad,
flattened, with a thin, parchmentlike covering
dorsally, solid and roughly granulate ventrally.
Appendages capable of being folded compactly
against body. Front margin of carapace nearly
semicircular in outline, margin densely ciliated,
deeply fissured in middle and with a shallow
notch on each side near middle. Ventral surface
without ridges, sloping evenly to anterior margin,
and with eyes, antennules, antennae, and mouth
parts deeply seated in depressions; a narrow fis-
sure in front of eye for lodgment of antennal
nagellum; outer posterior margin of orbit fis-
sured. Third maxillipeds completely closing buc-
cal cavity.

Figure 119. — Hypoconcha arcuata Stimpson. Anterior
portion of animal in ventral view, 3 mm. indicated.

144

FISH AND WILDLIFE SERVICE

Legs all stout, hairy, and coarsely granulate.
First pair chelate ; fingers somewhat spatulate and
toothed at tip, immovable finger articulated at
angle with hand. Second and third legs with
sharp, corneous tips; fourth and fifth legs borne
on dorsal surface, with penultimate article quite
short, and terminal article reduced to a small,
curved claw. Abdomen short and flexed so that
last two segments lie on thoracic sterna.

Measurements. — Carapace of male: length, 24
mm. ; width, 24 mm.

Color. — Gray.

Habitat. — This curious crab has been taken
from dredge hauls in Bogue Sound off Morehead
City, N.C. It is always found occupying a valve
of some lamellibranch shell, preferably a clam-
shell, which it carries about upon its back after the
manner of a hermit crab. By means of the claws
on its fourth and fifth pairs of legs, perhaps aided
by pressure of its body against the shell, it clings
so tightly that removing it from the shell without
crushing it is almost impossible. Shallow water
to 22 fathoms.

Type localities. — South Carolina sandy shores,
and St. Thomas, [V.I.].

Known range.— OR Cape Lookout, N.C, to west
Florida; St. Thomas, V.I. ; Surinam to State of
Espirito Santo, Brazil.

Hypoconcha sabulosa (Herbst)

Figure 120

Cancer sabulosa Herbst. 1799, p. 57, pi. 48, figs. 2-3.

Hypoconcha sabulosa: Hay and Shore, 1918, p. 418, pi. 31,
fig. 3. — Rathbun, 1937, p. 44, pi. 8, figs. 3-4, pi. 9, figs. 1-5
(rev.).

Recognition characters.— Body short, broad,
flattened, with front and lateral margin expanded,
with thin parchmentlike covering dorsally, solid
with surface nodulose, granulate, and marked by
several strong ridges ventrally. Carapace in old
individuals pubescent above; margin densely
hairy, and armed anteriorly with four curved
spines with sharp tips pointing obliquely down-
ward followed by a few other smaller spines;
front between median pair of spines subtruncate
or sloping slightly backward toward short, nar-
row, median fissure. Antennal fossae limited in
front by a pair of strong, oblique ridges arising
between two of spines of anterior border, meeting
each other in midline in front of epistome; epi-
stome with posterior border raised into a promi-

Figuke 120. — Hypoconcha sabulosa (Herbst). Anterior
portion of animal in ventral view, detail of right side
shown, 5 mm. indicated.

nent ridge continuing on either side across front
and some distance along sides of buccal area.
Basal articles of antennae tuberculate; proximal
article with a strong inwardly directed tooth,
distal article with a tooth on each side of base of
flagellum. Fissure in outer margin of orbit promi-
nent owing to development of a strong tubercle
on either side.

Carpal article of first pair of legs with several
dentate tubercles ; hand covered with more or less
pointed tubercles. Other legs and abdomen much
as in H. arcuata.

Measurements. — Carapace of female: length,
22 mm. ; width, 22 mm.

Color. — Gray; or, as described by Schmitt in
Kathbun (1937), coral sand above with whitish-
gray hairs, ground color beneath, red; rounded
bosses on legs and subf rontal region reddish
brown ; eyes black or reddish brown ; eggs orange.

Habitat. — A few feet to 49 fathoms.

Type locality. — Listed as "Africa" (probably
an error).

Known range. — Off Cape Hatteras, N.C, to
Sabine, Tex. ; Jamaica.

Remarks. — This species has been found in Beau-
fort, N.C, harbor, and, though it apparently has
habits similar to those of H. arcuata, it is much the
rarer of the two species. Rathbun (1937) listed
ovigerous females in June from Florida and in
October from North Carolina.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

145

Family Homolidae

Crabs with carapace rectangular, ovoid, or urn-
shaped, longer than broad. Eyes incompletely
sheltered by orbits when retracted, terminal joint
of eyestalk either longer or shorter than slender
basal joint. External maxillipeds pediform, sub-
pediform, or suboperculiform. Sternum of female
without longitudinal grooves. Gills 8, 10, 13, or
14 on each side (Rathbun, 1937, modified after
Gordon, 1950 ; Hemming, 1958c) .

Genus Hotnola Leach, 1815

Rathbun, 1937, p. 62. — Hemming, 1958c.

Homola barbata (Fabricius)

Figure 121

Cancer barbatus Fabricius, 1793, p. 460.

Homola barbata: Hay and Shore, 1918, p. 419, pi. 30, flg. 10.
Thelxiope barbata: Rathbun, 1937, p. 63, text-fig. 16, pi. 15,
figs. 1-2 (rev.).

Figure 121. — Homola barbata (Fabricius). Animal in
dorsal view (after Smith, 1887).

Recognition characters. — Carapace about one-
fourth longer than wide with surface granulate,
spinulose, and sparsely setose; Tinea anomurica
distinct and dorsal; sides nearly straight, only
slightly convergent posteriorly, and extending al-
most vertically downward from a spiny ridge run-
ning backward from behind a strong spine situ-
ated at extremities of suture separating gastric
and hepatic regions. Rostrum small, bifurcate at
tip; a spine on each side at base of rostrum, one at

outer orbital angle, a transverse row of two be-
hind rostrum, behind these a transverse row of
eight, and farther back a small median spine. An-
terolateral parts below and behind orbits with
small spines. Eyestalks long, slender at base, and
abruptly enlarged below cornea.

Chelipeds of moderate size, surface granulate
and hairy; merus and carpus with rows of spines.
Walking legs with flattened articles, long, hairy,
and spinulose along margins. Second segment of
abdomen with a large, median, conical tooth.

Measurements. — Carapace including rostrum :
male, length, 30 mm., width at base of lateral
spines, 22 mm., posterior width, 16 mm. ; female,
length, 33 mm., width at spines, 25 mm., posterior
width, 20 mm.

Color. — "Body covered with tawny or yellow-
ish-brown or reddish-brown hair; spines red or
partly red'' (Rathbun, 1937).

Habitat.— Thirty to 373 fathoms.

Type locality. — Bay of Naples.

Known range. — Off southeastern Massachusetts
to Caribbean Sea; eastern Atlantic Ocean from
Portugal and Azores to Madeira Islands; Medi-
terranean Sea ; South Africa.

Remarks. — This essentially deep-water species
has been reported in 63 fathoms off North Caro-
lina. Ovigerous females have been reported in
October off Delaware Bay (Rathbun, 1937), and
are known off North Carolina and Florida in June
and July.

Gordon (1950) discussed the anatomical struc-
ture of the spermathecae of females and copula-
tory apparatus of males in the genus Homola, and
remarked upon the evolutionary sequence shown
by these structures in the Dromiacea. ■

Subsection Oxystomata

Epistome reduced or absent. Efferent branchial
channels terminating at middle of buccal area,
buccal cavern produced forward and generally
elongate-triangular in shape, efferent channels
enclosed by an elongate lamellar process of
exopods of first maxillipeds. Afferent branchial
openings either in front of bases of chelipeds, or
at sides of endostome. Gills six to nine on each
side. Antennules Folding either longitudinally or
obliquely, rarely transversely. Male genital ducts
protruding through bases of fifth legs or through

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FISH AND WILDLIFE SERVICE

fifth thoracic sternum nearby. (Modified after
Alcock, 1896, in Rathbun, 1937.)

Family Leucosiidae

Crabs having carapace circular, oval, or polyg-
onal. Eyes and orbits small, front narrow but
wider than orbit. Antennules folding more or less
obliquely. Antennae small. External maxillipeds
completely enclosing buccal cavity, except often
a small crevice in front. Afferent branchial chan-
nels occupying sides of endostome on either side
of deep, median, endostomal groove serving as an
efferent branchial channel. Afferent channels
covered by exognaths of external (third) maxilli-
peds, efferent channels by a pair of lamellar proc-
esses of first maxillipeds. Chelipeds symmetrical.
Abdomen hidden beneath thorax, commonly with
third to sixth abdominal terga fused, sixth some-
times free. Vasa deferentia opening on fifth
thoracic sternum near bases of last pair of legs.
(Modified after Alcock, 1896, in Rathbun, 1937.)

KEY TO GENERA AND SOME SPECIES IN THE
CAROLINA S

a. Carapace polygonal, uneven, nodular, or eroded

Subfamily Ebaliinae (p. 147).
b. Posterior portion of carapace without deep cavities

Ebalia cariosa (p. 147).
bb. Posterior portion of carapace with a deep rounded

cavity on each side Spetoeophorus (p. 148).

aa. Carapace ovoid or globular, and smooth or granular
Subfamily Philyrinae (p. 150).
b. Fingers opening in horizontal plane

Persephona punctata aguilonaris (p. 150).
bb. Fingers opening in vertical plane

Iliacantha (p. 150).

Subfamily Ebaliinae

Surface of carapace uneven. Chelipeds of mod-
erate length; fingers not very thin and elongate,
dactyl moving in an oblique plane. Anterior mar-
gin of buccal cavity arcuate, middle part in front
of level of anterior pterygostomian region. Epi-
stome and infraorbital lobe well developed. Ptery-
gostomian margin extending either slightly or dis-
tinctly forward, terminating in an indentation.
Merus of external maxillipeds half or more than
half length of ischium measured along inner bor-
der. First abdominal segment in female often
under carapace (Rathbun, 1937).

Genus Ebalia Leach, [1817]

Rathbun, 1937, p. 123. — Hemming, 1958b, p. 15.
Ebalia cariosa (Stimpson)

Figure 122

Lithadia cariosa Stimpson, 1860a, p. 238. — Hay and Shore,
1918, p. 424, pi. 32, fig. 6.

Ebalia cariosa: Rathbun, 1937, p. 125, pi. 35. figs. 6-7 (rev.).

Figure 122. — Ebalia cariosa (Stimpson). Animal in dor-
sal view, legs of left side not shown, 3 mm. indicated.

Recognition characters. — Carapace convex,
roughly pentagonal; anterior angle truncate, lat-
eral angles obtuse; surface uneven and covered
everywhere, including other parts of body and
legs, with beadlike granules, larger posteriorly
and ventrally. Front narrow, upturned, and
broadly notched, connected with middle protuber-
ances by a median ridge traversing gastric region ;
ridge flanked on each side by a sinuous, deep,
broad excavation of darker color than protuberant
parts. Anterolateral margin of hepatic region
sinuous, hepatic region slightly prominent, de-
limited posteriorly by an impressed line. Ptery-
gostomian region with a large downward-point-
ing tooth, hardly visible in dorsal view. Postero-
lateral margin with a broad tooth, separated from
bilobate intestinal region by a deep sinus; cardiac
and inner lobules of branchial region strongly
protuberant, separated from thick intestinal lobes
by a deep narrow sulcus.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

147

Chelipeds stout, a little longer than width of
carapace, joints angular ; merus as broad as hand,
outer margin convex and a little irregular; hands
rather small, tapering to rather slender ringers.
Walking legs cylindrical. Abdomen of male nar-
row, triangular, with a backward projecting spine
at proximal end of penultimate segment. Abdo-
men of female with penultimate segment very
large, nearly circular.

Measurements. — Carapace: length of male, 12
mm., width, 13 mm.; female, length, 13 mm.,
width, 15 mm.

Color. — Light gray or buff, female occasionally
with two or three small red spots on abdomen;
other specimens may be pale red (Rathbun, 1937).

Habitat. — Below low-tide mark to 25 fathoms.

Type locality. — Beaufort, N.C.

Known range. — Bogue Sound near Beaufort,
N.C, to west Florida; Jamaica; northeastern
South America to Rio de Janeiro, Brazil.

Remarks. — This species is occasionally found in
channels in the Beaufort, N.C, harbor. The spe-
cies feigns death when brought on deck in a
dredge haul, and, thus, closely resembles the peb-
bles and pieces of shell among which it appears to
live. Ovigerous females are found at this locality
throughout the summer.

Genus Speloeophorus Milne Edwards, 1865

Rathbun, 1937, p. 141.

KEY TO SPECIES IN THE CAROLINAS

a. Lateral portions of carapace tumid, not expanded into
wings ; deep cavity of carapace with only two openings,
not visible dorsally nodosus (p. 149).

aa. Lateral portions of carapace expanded into broad,
flattened wings ; deep cavity of carapace with four
openings, two visible dorsally pontifer (p. 149).

Speloeophorus nodosus (Bell)

Figures 123-124

Oreophorus nodosus Bell, 1855, p. 307, pi. 33. fig. 8.
Speloeophorus nodosus: Hny and Shore, 1918, p. 425, pi. 32,
fig, 5.— Rathbun, 1937, p. 142, pi. 40, flgs. 15

Recognition characters. — Carapace convex,
roughly pentagonal or hexagonal, broader than
long, posterolateral angles rounded; surface no-
dose, evenly and thickly covered everywhere with
crowded, rounded granules. Front thick, bilobed,
upturned; a prominent broad ridge extending
backward from front to cardiac region. Hepatic
region to each side with a low hump, behind this,

Figure 123. — Speloeophorus nodosus (Bell). Animal in
dorsal view, legs of left side not shown, 3 mm. indi-
cated.

Figure 124. — Speloeophorus nodosus (Bell). Animal in
posterior view, 3 mm. indicated.

at side of gastric region, a much larger hump,
and still farther back, near posterior border, an-
other of nearly equal size; posterior- humps over-
hanging and largely containing a deep cavity with
two openings invisible in dorsal view. Subhepatic
region with a nodose prominence near front, and
farther back two others of smaller size.

Chelipeds short, stout, coarsely granulate,
crested along outer margin ; merus with large
distal and small proximal lobe; fingers thin, flat,
grooved. Walking legs crested, crests dentate or
narrowly lobed.

Measurements. Carapace: length of male, L2
nun., width, 15 nun.; female, length, 17 mm.,
width, 21 mm.

Variations. Carapace of males much more un-
even than that of females.

148

FISH AND WILDLIFE SERVICE

Color. — Pink with a few purplish spots on cara-
pace and rusty-brown marks on legs. Rathbun
(1937) described this species as looking like a
dead piece of coral overgrown with purplish and
greenish algae, with patches of red ones; chelae
with natural greenish cast; reticulations around
whitish areas of green hue; fingers dull white with
articulations pink; legs dirty white with greenish,
reddish, and whitish spots; eyes not distinguish-
able from rest of body; underparts dirty white,
abdomen greenish.

Habitat, — One and one-half to 10 fathoms.

Type locality. — Unknown.

Known range. — Off Morehead City, N.C., to
southern Florida ; West Indies.

Remarks. — This species is rare in the northern
part of its range and was most recently reported
by Pearse and Williams (1951) from reefs off
Beaufort Inlet, N.C. The species readily plays
dead when brought on deck.

Speloeophorus pontifer (Stimpson)

Figures 125-126

Lithadia pontifera Stimpson, 1871b. p. 115.

Speloeophorus pontifera: Hay and Shore, 1918, p. 425, pi. 32,
flg. 5.

Speloeophorus pontifer: Rathbun, 1937, p. 144, pi. 39, figs. 1-3
(rev.).

Recognition characters. — Carapace angular,
roughly trefoil shaped, from one-third to one-
sixth wider than long; surface granulate, uneven.
Lateral margin of each side extended into a broad
wing projecting over bases of legs; anterolateral
margins concave, with notch near middle; pos-
terolateral margins broad, with a deep rounded
cavity to each side of intestinal region, extending
toward and almost to much smaller pit on dorsal
surface at side of cardiac region, a narrow suture
connecting cavity and pit of each side. Front nar-
row, produced, upturned, and with a deep median
sinus. Orbits small. A middorsal ridge extending
from front almost to posterior margin, ridge in-
terrupted in middle of carapace ; branchial region
on each side with a prominent elevation more or
less divided into two parts, one connected by a
ridge to anterior angle of lateral wing, other simi-
larly connected to posterior angle. Hepatic region
small, slightly elevated; pterygostomian region
prominent, with conical downward-pointing
eminence visible from above.

Chelipeds of moderate size, somewhat crested;
merus with two large triangular teeth on outer

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 O— 65 11

Figure 125. — Speloeophorus pontifer ( Stimpson ) . Female
in dorsal view, 3 mm. indicated.

Figure 126. — Speloeophorus pontifer (Stimpson).
in posterior view, 3 mm. indicated.

Female

margin; fingers slender and curved. Walking
legs granulate and tuberculate.

Abdomen tuberculate; segments three to five
only partially fused ; sixth segment with a sharp,
backward pointing, proximal spine.

Measurements. — Carapace: length of male, 6
mm., width, 8 mm. ; female, length, 10 mm., width,
13 mm.

Variations. — This small species apparently at-
tains a width of about 15 mm., and is extremely
variable. The ridges and elevations of the dorsal
surface may be sharp and conspicuous or low and
rounded; the lateral angles of the lateral wings
of the carapace may be produced or rounded off.
The female is not so wide in proportion to length
as the male, and is somewhat tumid on the outer
posterior part of the lateral wings.

Color. — Pale red in middle, remainder white
(von Martens in Rathbun, 1937. )

149

Habitat. — Low tide to 125 fathoms.
Type locality. — Barbados.
Known range. — Off Beaufort, N.C., to
Florida ; West Indies to Barbados.

west

Subfamily Philyrinae

Carapace almost hemispherical, surface only
slightly uneven. So-called frontal teeth often be-
ing well-developed inner-orbital angles. A me-
dian frontal tooth often present. Infraorbital lobe
seldom well developed, roof of efferent branchial
channel usually reaching same level. Epistome
usually reduced. Margins of mouth and ptery-
gostomian region in same transverse plane. Merus
of external maxillipeds half or more than half
length of ischium measured along inner border.
First abdominal segment in female often under
carapace (Rathbun, 1937).

Genus Persephona Leach, 1817

Rathbun, 1937, p. 151.— Hemming, 1958b, p. 18.

Persephona punctata aquilonaris Rathbun. Purse crab

Figure 127

Persephona punctata Stimpson, 1859 (in part), p. 70. — Hay
and Shore, 1918 (ill part), p. 423, pi. 32, fig. 9.

Persephona punctata aquilonaris Rathbun, 1937, p. 154, pi. 42,
figs. 6-7 (rev.).

Recognition characters. — Carapace globular,
thickly strewn dorsally and laterally with gran-
ules of various sizes, and with three sharp, re-
curved spines, one at each end of posterior margin
and one median just above posterior margin.
Front narrow, broadly bidentate, produced and
elevated, and with dentiform angles of branchial
channels projecting slightly beyond it. Anterior
and lateral regions bounded externally by a row
of beadlike granules broken anteriorly by a single
tubercle of larger size, and posteriorly extending
to a point nearly opposite termination of posterior
margin.

Chelipeds subcylindrical in adult male, ap-
proximately 1.5 times as long as carapace; merus
with many large tubercles; carpus and chela
nearly smooth except on margins; chela somewhat
Hat .iiid dilated; fingers weak.

Measurement*. — Male: length of carapace to
tip of posterior spine, 48 mm.: to base of spine,
15 mm. : width, 42 mm.

Color. — Gray to grayish brown, with darker
brownish irregular spots or marniorat ions: gran-
ules white or tinged with red.

Figure 127. — Persephona punctata aquilonaris Rathbun.
Animal in dorsal view, detail of left side shown, 5 mm.
indicated.

Habitat. — This crab is sometimes taken in otter
trawls but usually by dredging in shelly mud in
relatively shallow water in the ocean; 2 to 30
fathoms.

Type locality. — St. Augustine, Fla.

Known range. — Xew Jersey to Campeche, Mex-
ico ( Hildebrand, 1954, in part ) .

Remarks. — The species is fairly abundant in
colonies. The purselike receptacle formed by the
enormously enlarged penultimate segment of the
abdomen in the female may be found filled with
eggs at almost any time during spring and sum-
mer.

Genus Iliacantha Stimpson, 1871

Rathbun. 1937, p. 183.

KEY TO SPECIES IN THE CAROLINAS

a. Fingers longer than palm of hand-subatobosa (p. 150).
aa. Fingers about half as long as palm of hand

intermedia (p. 151).

Iliacantha subglobosa Stimpson
Figure 128
Iliacantha subglohosa Stimpson, 1871a, p. 155. — Hay and
Shore. 1918, p. 424. pi. 32, fig. 2. — Rathbun, 1937. p. 185, pi. 53,
figs. 1-2 (rev.).

150

FISH AND WILDLIFE SERVICE

Figure 128. — Iliacantha subglobosa Stimpson. Female in
dorsal view, 5 mm. indicated.

Recognition characters. — Carapace orbicular,
smoothly and evenly convex, finely granulate, un-
armed except posterior border with three spines ;
lateral spines subtriangular, blunt; median one
higher, longer, conical, and curved upward. Front
deeply grooved above, broadly notched anteriorly
and with spiniform angles of branchial channels
extending beyond it. Margin of carapace distinct,
somewhat acute on hepatic region and anterior
portion of branchial region, indistinct beyond ;
hepatic region swollen; intestinal region slightly
protuberant above base of median spine.

Chelipeds 2.5 times as long as carapace, exclud-
ing spine, finely granulate; merus more sharply
granulate than carpus and hand ; fingers slender,
longer than palm, armed with needlelike teeth.
Walking legs slender, smooth; merus as long as
three terminal articles; dactyls grooved, and with
two fringes of hair on upper and posterior sur-
faces. Male abdomen gradually tapering from
fifth to seventh segment.

Measurements. — Male: carapace length, 21
mm., width, 16 mm.; chela length, 22 mm.; fin-
gers, 13 mm.

Habitat. — Fifteen to 215 fathoms.

Type localities. — Three stations in Florida
reefs, 40-80 fathoms.

Known range. — Off Cape Hatteras, N.C., to
northwest Florida ; through West Indies to Bar-
bados.

Remarks. — Ovigerous females have been taken
in June from the Gulf of Mexico.

Iliacantha intermedia Miers

Figure 129

Iliacantha intermedia Miers, 1886, p. 302, pi. 26, flgs. 3, 3a. —
Hay and Shore, 1918, p. 424, pi. 32, fig. 3.— Rathbun, 1937, p. 186,
pi. 54, figs. 1-2 (rev.).

Figure 129. — Iliacantha intermedia
Miers. Male in dorsal view, 5 mm.
indicated.

Recognition characters. — Similar to /. subglo-
bosa, but carapace more coarsely granulate; pos-
terior spines shorter, flattened, triangular, con-
nected by prominent line of granules. Front
deeply grooved above, broadly notched anteriorly,
and with spiniform angles of branchial channels
extending beyond it. Margin of carapace dis-
tinctly granulate; intestinal region not protuber-
ant above median spine.

Chelipeds slender, nearly as long as carapace;
merus cylindrical and granulate with coarser
granulations proximally; hand smooth, somewhat
inflated proximally but tapering to slender fin-
gers ; fingers about half as long as palm, incurved
at tip, and denticulate on opposed margins. Male
abdomen widened at convex-sided sixth segment.

Measurements. — Male: carapace length, 16
mm., width, 12 mm. ; chela, length, 13 mm. ; fin-
gers, 4 mm. Female: carapace length, 27 mm.,
width, 21 mm.

Color. — Gray without markings of any kind.

Habitat. — Five and one-half to 180 fathoms.

Type locality. — Bahia, Brazil.

Known range. — Off Beaufort, N.C., to north-
west Florida; St. Thomas, V.I.; Venezuela;
Bahia, Brazil.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

151

Remarks. — The young of this species and Per-
sephona punctata aquilonaris have a close resem-
blance.

Family Calappidae

Oxystomata of normal crablike form with ab-
domen hidden beneath thorax. Antennae small.
Afferent openings of gill chambers in front of
chelipeds. Outer maxillipeds not completely clos-
ing buccal cavity. Male openings coxal on fifth
pair of legs.

Calappid species are known from the Cretace-
ous to the present in North America (Rathbun,
1935).

KEY TO GENERA AND ONE SPECIES IN THE
CAROLINAS

a. Posterolateral region of carapace expanded and dentate

Calappa (p. 152).
aa. Posterolateral region of carapace not expanded,
b. Merits bispinous on distal outer surface with lower
spine strong and greatly extended laterally

Acanthocarpus alexaMri (p. 156).
bb. Merus not bispinous or distal outer surface,
c. Carapace considerably broader than long, regu-
larly convex above Hepatus (p. 157).

ce. Carapace nearly as long as broad, dorsal surface
uneven Osachila (p. 159).

Subfamily Calappinae

Merus of external maxillipeds almost never
elongate and acute, never concealing palp in re-
pose. Legs adapted for walking (Alcock in
Rathbun, 1937).

Genus Calappa Weber, 1795

Rathbun, 1937, p. 197.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace widest behind middle; proximal tooth on
lower edge of hand with margin pointed or angled,
b. Carapace smoothly granulate.

c. Carapace often with a horizontal tooth or spine at
either end of posterior margin ; smooth area on
lower half of palm on cheliped narrow proximally,
widening and continued obliquely upward distally

sulcata i v. 155).

cc. Carapace without a horizontal tooth or spine at

either end of posterior margin ; smooth area on

lower half of palm on cheliped concave, not directed

Obliquely upward distally.

d. Male with basal width of fifth abdominal seg-
ment twice median length; female with a few
granulations near lateral border of fourth ab-
dominal segment flammea i p. 152).

dd. Male with basal width of fifth abdominal seg-
ment less than twice median length ; female with
no granulations near lateral border of fourth

abdominal segment ocellata (p. 153).

bb. Carapace covered with rough protuberances, and

granulate angusta (p. 154).

aa. Carapace widest in front of middle ; proximal tooth
on lower edge of hand with margin not pointed or
angled angusta (young) (p. 154).

Calappa flammea (Herbst)

Figures 130-131

Cancer flammeus Herbst, 1794, p. 161, pi. 40, fig. 2.
Calappa flammea: Hay and Shore, 1918, p. 421, pi. 31. fig. 8. —
Holthuis, 1958, p. 148, figs. 28-35 (rev.).

Figure 130. — Calappa flammea (Herbst). Female from
Tortugas, Florida, in dorsal view, approximately X
0.66 (after Holthuis, 1958) .

Figure 131. — Calappa flammea (Herbst). A, male first
pleopod in ventral view, X 3 ; B, male second pleopod
in dorsal (anterior) view, X 3; C, abdomen of male,
approximately X 0.8; D, abdomen of female, approxi-
mately X 0.8; A-C from Tortugas, D from Bahama Is-
lands (after Holthuis, 1958).

152

FISH AND WILDLIFE SERVICE

Recognition characters. — Carapace 1.14 to 1.42
times broader than long, varying from smaller to
larger ratio with increasing size; surface granu-
lar, less conspicuously so in posterior half, tuber-
culate anteriorly, becoming obsolescent in adults;
branchiocardiac grooves distinct. Front deeply
notched anteriorly, projecting somewhat beyond
orbits; anterolateral borders together forming a
semicircle in younger specimens, less strongly
arched in adults. Posterolateral winglike expan-
sions of carapace distinct, consisting of five broad
teeth with beaded edges, second and third witli
sharp but not pointed apices, fifth tooth with
notch on inner basal part.

Chelipeds with outer surface of palm divided
into three horizontal zones: a lower one with
many large granules; a second zone, slightly
sunken, with no large granules but with scattered
small ones, more in males than females; a third
zone occupying whole upper half of outer surface
of palm, separated from second zone by a row of
small granules, bearing many small granules, and
some large low granular tubercles, more densely
granulated than second zone in females, same in
both in males. Upper margin of large hand with
about seven teeth, six on small hand ; proximal
teeth broad, low, and bifurcated. Palm with
strong tooth on outer lower surface near carpus,
apex of tooth approximately rectangular with a
sharp tip. Fingers of crushing hand somewhat
stouter than on cutting hand, and with prominent
projecting lobule near base of each. Merus with
strong four-toothed crest parallel with outer dis-
tal border.

Male with abdomen narrow; third to fifth seg-
ments fused, fifth segment with basal width twice
median length, sixth with width greater than
length, seventh with length about 1.5 times width.
Female with a few granulations near lateral bor-
der of fourth segment; length of seventh segment
equal to or slightly greater than width.

Measurements. — Carapace: male, length, 99
mm., width, 136 mm. ; female, length, 106 mm.,
width, 135 mm.

Color. — Ground color of carapace gray behind,
shading to drab mottled with white over greater
portion; reddish blue on outer surface of cheli-
peds becoming almost white on lower half of palm
and on fingers ; inner surface of cheli peds, ptery-
gostomian regions, anterior surface of first walk-

ing legs, and a small part of second walking legs
reddish hued. Carapace with color pattern varia-
ble, purplish brown in interlacing bands on ante-
rior half, obliquely longitudinal stripes on pos-
terior half becoming lighter posteriorly. Merus,
carpus, and proximal upper portion of palm
striped with purplish brown, two distinct round
spots of same color in middle of palm ; upper half
of palm with spots and patches of sulphur yellow
on teeth and tubercles and same color mixed with
ground color of merus, carpus, and part of cara-
pace; two or three orange spots on hands near
base of dactyls and spots of same near articulation
of palm and carpus. Third to fifth legs, and un-
derparts whitish. (Adapted from R. L. Barney
in Rathbun, 1937.)

Habitat. — This strikingly colored crab does not
often occur within the harbor at Beaufort, N.C.,
but is often brought up from a few fathoms out-
side the inlet. Those obtained inside are usually
small. Hildebrand (1955) listed the species as
common from 6 to 16 fathoms on the Campeche
Banks. The species may spend much time buried
in sand (Pearse, Humm, and Wharton, 1942).

Habitat. — Surface to 40 fathoms, rarely to 125
fathoms.

Type locality. — America.

Known range. — Cape Hatteras, N.C., to Florida
Keys; Gulf coast of United States and Mexico;
Bahamas; Bermuda.

Remarks. — This species has a fossil record in
North America dating from the Oligocene (Rath-
bun, 1930b).

The breeding range of the species extends as
far northward as Cape Hatteras, but in the larval
stages it often drifts as far to the north as south-
ern New England. Some of these larvae are sup-
posed now and then to survive a mild winter and
develop by the next summer into the small speci-
mens which have at rare intervals been taken on
the coast of Massachusetts and Rhode Island.
Some of the larval stages have been figured by
Lebour (1944). Smith (1880b) gave a descrip-
tion of the megalops stage of this species.

Calappa ocellata Holthuis

Figures 132-133
Holthuis, 1958, p. 158, figs. 36-10 (rev.).

Recognition characters. — Carapace slightly
narrower than in C. fl,ammea, having width to

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

153

Sssffiiip

Fioube 132. — Calappa ocellata Holthuis. Male from
Curagao in dorsal view, approximately natural size
(after Holthuis, 1958).

Fioure 133. — Calappa ocellata Holthuis. A, male first
pleopod in ventral view, X 3 ; B, male second pleopod in
dorsal (anterior) view, X 3; C, abdomen of male, ap-
proximately X 0.8 ; D, abdomen of female, approxi-
mately X 0.8; A-D from Dutch West Indies (after
Holthuis, 1958).

length ratio of 1.15 to 1.40, varying from smaller
to larger ratio with increasing size; granulations
much coarser than in C. flammed, granules larger,
fewer, and more widely separated. Posterolateral
winglike projections distinctly set off from an-
terolateral margin, teeth with slender pointed
tips, more slender than in ('. flammea, notch in
basal part of fifth tooth inconspicuous.

Chelipeds similar to C. flammea, though second
and third zones of outer palm nearly alike in both

males and females. Upper margin with teeth nar-
rower proximally than in C. flammea, and with
bifurcation indistinct or absent. Palm with strong
tooth on outer lower surface near carpus, apex
sharply pointed with an acute tip. Teeth on crest
of merus more sharply pointed than in 0. flammea.

Male with abdomen narrower than in C. flam-
mea; third to fifth segments fused, fifth segment
with basal width less than twice median length,
sixth with width equal to or less than length,
seventh more slender than in C. flammea. Females
with no granules near lateral border of fourth
segment; length of seventh segment distinctly
greater than width.

Measurements. — Male holotype : length of cara-
pace, 83 mm. ; width, 114 mm.

Color. — In preserved specimens, anterior half
of carapace red with numerous white, often ocel-
lated, spots and a few white streaks, the whole
forming a reticulate pattern of red. Pattern more
compact and complete than in C. flammea, extend-
ing over full width of anterior half of carapace,
absent in posterior half showing only a few dis-
tinct spots between teeth of posterolateral wings,
and two red spots before posterior margin above
bases of last legs. Chelipeds with one or two red
spots near articulation of dactyls; red between
teeth of upper margin ; inside of chelipeds reddish
(Holthuis, 1958).

Habitat. — Shallow water to 14 fathoms.

Type locality. — Klein Bonaire, Dutch West
Indies.

Known range. — Cape Hatteras, N.C., to State
of Pernambuco, Brazil ; Bermuda.

Remarks. — This species is less common than C.
flammea from Tortugas northward (Holthuis,
1958).

Calappa angusta Milne Edwards

Figure 134

Calappa angusta Milne Edwards, 1880, p. 18. — Hay and Shore,
1918, p. 421, pi. 31, fig. 7. — Rathbun, 1937, p. 210, pi. 64. figs. 1-6
(rev.).

Recognition characters. — Carapace eight-ninths
as long as wide; anterolateral margins finely gran-
ulate with larger granules at intervals; surface
covered with protuberances, granulate between.
Tooth at posterolateral angle of winglike exten-
sion of carapace largest, preceded anteriorly by
four teeth gradually diminishing in size, and fol-
lowed posteriorly by one small and one or two

154

FISH AND WILDLIFE SERVICE

Figure 134. — Calappa angusta Milne Edwards. Animal
from North Carolina in dorsal view, approximately X
1.8.

extremely small teeth. Orbit completely separated
from antennular cavity.

Chelipeds with outer surface of palm divided
into three zones as in preceding species; upper
margin with six to eight teeth. Abdomen with
sixth segment subquadrate ; seventh segment sub-
triangular, slightly longer than wide.

Measurements. — Carapace: male, length, 28
mm., width, 32 mm.; female, length, 23 mm.,
width, 28 mm.

Variations. — Posterior part narrower than
middle of carapace in juveniles, wider than
middle in adults.

Color. — Ground color buff to buff yellow ; high
spots or lumps on carapace and chelipeds red.
Marginal spines of carapace, crest of chela and
lumps on crest drab. Hairs of carapace, espe-
cially those of hind margin, light olive yellow;
those of walking legs light citrous yellow. Merus
of chelipeds practically colorless. Under parts
whitish, pterygostomian region and maxillipeds
suffused with pale purple (Schmitt in Rathbun,
1937).

Habitat. — More abundant in the Gulf Stream
than in adjacent inshore waters; 7.5 to 115 fath-
oms, rarely deeper.

Type locality. — Barbados.

Known range. — Off Cape Lookout, N.C.,
through eastern Gulf of Mexico, to Grenada.

Remarks. — Ovigerous females have been taken
from southern Florida in March.

Calappa sulcata Rathbun

Figures 135-136

Calappa sulcata Rathbun, 1898, p. 289, pi. 0, figs. 3-4.— Hay
and Shore, 1918, p. 422, pi. 31, fig. 6.— Holthuls, 1958, p. 179,
figs. 51-54 (rev.).

Recognition characters. — Carapace somewhat
wider than long, covered with uniform granula-
tions giving appearance of being smooth. Antero-
lateral margins crenulate and granulate, grading
into inconspicuous anterolateral wings; teeth tri-
angular, pointed. Posterior margin with tooth at
each end near base of abdomen, sharper in males
than in females, very low in adults, most slender
and sharp in juveniles; third tooth of postero-
lateral wings extremely sharp and slender,
pointed in juveniles.

Figure 135. — Calappa sulcata Rathbun. A, large chela in
external view ; B, female in dorsal view ; 30 mm. in-
dicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

155

Figube 136. — Calappa sulcata Rathbun. A, male first
pleopod in ventral view, approximately X 3 ; B, male
second pleopod in dorsal (anterior) view, approximately
X 3 ; C, abdomen of male, approximately X 0.8 ; D,
abdomen of female, approximately X 0.6 ; A-C from
near Margarita Island, Venezuela ; D from Surinam
(after Holthuis, 1958).

Chelipeds with outer surface of palm divided
into three zones as in preceding species; large
tubercles of lower zone low and inconspicuous;
zones one, two, and three each separated by a row
of sharply pointed tubercles; middle zone not
extending horizontally, but curving dorsally in
distal part, smooth, with minute granules; zone
three smooth, except for two low, inconspicuous,
granular tubercles near upper margin of palm;
granulations on palm more distinct in females
than in males; tooth on outer, lower, proximal
surface of palm nearly rectangular in large in-
dividuals, slender and acute in smaller ones. Meral
articles of walking legs with granules on lower
surface.

Measurements. — Carapace: male, length, 77
mm., width, 98 mm.; female, length, 92 mm.,
width, 119 mm.

Color. — In alcohol, often light pinkish brown
with small, narrow rings of dark red, median ring
most conspicuous; each carpus with a ring, and
each palm with one near upper margin enclosing
tubercle toward proximal end of margin (Rath-
bun, 1937).

Habitat. — Twelve to 100 fathoms (Cerame-
Vivas, personal communication).

Type locality.— Oft Louisiana, lat. 29°24'30" N.,
long. 88°0r W., depth, 35 fathoms.

Known range. — Cape Hatteras, N.C., to Gulf of
Mexico; through West Indies to French Guiana.

Remarks. — Hildebrand (1954) reported this
species (under the name C. spring en) as con-
spicuous but never abundant in the western and
northwestern Gulf of Mexico at depths of 12 to
35 fathoms. One ovigerous female was found in
May off Padre Island, Tex.

Genus Acanthocarpus Stimpson, 1871

Rathbun, 1937, p. 220.

Acanthocarpus alexandri Stimpson

Figure 137

Acanthocarpus alexandri Stimpson, 1871a, p. 153. — Rathbun,
1937, p. 221, pi. 69, figs. 1-2 (rev.).

Recognition characters. — Carapace ovate, regu-
larly convex, widest in anterior half; surface un-
even, granulate, and punctate, with protuberances
arranged longitudinally in roughly five rows cen-
trally, and two shorter, intercalated rows behind
orbits; all rows formed into ridges, those adjacent
to midline each terminating in a spine on postero-
lateral margin. Posterior margin arcuate bearing
a low eminence at middle; inferior margin of
pterygostomian region with a row of 7 to 11
strong, widely spaced, oblique ridges of varying
length. Orbits large, margins ciliated.

Chelipeds strong; merus bispinose on distal
outer surface, inferior spine strong and a little
longer or shoiter than half width of carapace,
superior spine one-fourth to one-third length of
inferior spine; hand with superior crest of 7
closely placed teeth, and an oblique 6-toothed crest
on outer surface extending from base of dactyl to
posteroinferior angle, scattered tubercles between
crests; inner surface of hand with stridulating
ridge composed of about 45 oblique, closely placed
striae which can be played against oblique ridges
of peterygostomian region. Walking legs smooth.
Sternal plastron with a conical tubercle on either
side of first article.

Measurements. — Male carapace: length, 13
mm. ; width, 32 mm.

Color. — Dorsal surface of carapace and cheli-
peds pale reddish orange, deepest in hue on eleva-
tions of carapace and bases of meral spines of
chelipeds; underparts white, slightly tinged with
red (Rathbun, 1937).

Habitat.— Thirty-seven to 208 fathoms.

156

FISH AND WILDLIFE SERVICE

Figure 137. — Acanthocarpus alexandri Stimpson. Male
in dorsal view, walking legs of left side not shown, 10
mm. indicated.

Type locality. — Off the Quicksands, Florida
Keys, 74 fathoms.

Known range.- — Georges Bank off Massachu-
setts to west coast of Florida; Puerto Rico to
Grenadines; Brazil (Da Costa, 1959).

Remarks. — The species has been recorded off
both Carolinas, usually at depths greater than 100
fathoms. One collection was taken off South
Carolina in 1950 at 60-65 fathoms along with
Sicyonia and Hymenopenaeus sp.

Rathbun (1937) reported ovigerous females in
June and July from Florida.

Subfamily Matutinae

Merus of external maxillipeds elongate and
acute, entirely concealing palp in repose (Alcock
in Rathbun, 1937).

Genus Hepatus Latreille, 1802

Rathbun, 1937, p. 234.— Holthuis, 1959, p. 173.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace covered with small spots ; front bidentate

pudibundus (p. 157).
aa. Carapace covered with large spots ; front truncate

epheliticus (p. 158).

Hepatus pudibundus (Herbst)

Figures 138-139

Cancer pudibundus Herbst, 1785, p. 199.

Hepatus princeps: Rathbun, 1937, p. 235, pi. 70, figs. 1-2
(rev.).

Hepatus pudibundus: Holthuis, 1959, p. 167, figs. 36-38a, b
(rev.).

Recognition characters. — Carapace between
two-thirds and three-fourths as long as broad,
relatively narrower in juveniles than in adults,

covered with transverse lines or small spots,
strongly convex. Surface smooth in adults; juve-
niles with eight distinct rows of tubercles, three in
a transverse line in broadest part of carapace, two
others in front and three behind. Front thick,
obtuse, slightly bidentate. Anterolateral margin
divided into 12 or 13 more or less rectangular
teeth, denticulate on margins and not projecting;
anterior portion of posterolateral margin con-
sisting of 2 rows of tubercles placed side by side
with no space between, a small tooth in middle of
rows and another in posterior portion of this
margin.

Outer face of hands with five rows of tubercles
exclusive of marginal ones. Dactyls of walking
legs with a coating of short, dense pubescence, ex-
cept for tip, and a narrow smooth line on each
side.

Measurements. — Carapace: males, length, 16-
55 mm., width, 21-76 mm.; females, length, 14-
46 mm., width, 18-62 mm. (Holthuis, 1959).

Color. — "Pale yellowish brown, with dark-
brown transverse lines, or transverse series of
spots; legs subochreous [sic], with one or two
large purplish blotches in each joint." (Dana in
Rathbun, 1937.) Holthuis (1959) gave the color
in preserved specimens. Carapace covered with
small reddish dots, scattered or sometimes ar-
ranged into transverse bands or lines, larger pos-
teriorly than anteriorly; similar dots on carpus
and palm; walking legs with two conspicuous
broad bands of reddish color on merus, one on
carpus and one on propodus, meral bands most
distinct on last leg.

Figure 138. — Hepatus pudibundus (Herbst). Female in
dorsal view, approximately natural size (after Hol-
thuis, 1959).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

157

Figure 139. — Hepatus pudibundus (Herbst) . A, male first
pleopod ; B, male second pleopod ; A-B approximately
X 8 ; C, abdomen of male ; D, abdomen of female ; C-D
approximately X 2 (after Holthuis, 1959).

Habitat. — Beach to 6 fathoms.

Type locality. — Martinique.

Known range. — Georgia to State of Sao Paulo,
Brazil.

Remarks. — Holthuis (1959) reported an ovig-
erous female in April from Surinam. Several of
the specimens Holthuis studied carried one or
more sea anemones on the carapace and one bore
barnacles.

Hepatus epheliticus (Linnaeus) Calico crab, Dolly Varden
crab

Figure 140

Cancer epheliticus Linnaeus. 1763, p .414.

Hepatus epheliticus: Hay and Shore, 1918, p. 422, pi. 37,
flg. 1. — Rathbun, 1937, p. 238, pi. 70, figs. 3-4; pi. 71, figs. 1-4
(rev.).

Recognition characters. — Carapace covered
with large spots, about two-thirds as long as wide,
convex above, regularly arcuate in front, strongly
narrowed behind, almost smooth, with indistinct
lines of low granules on gastric region and pos-
terior part of branchial region. Front narrow,
truncate, tuberculate, not dentate, and placed
higher than continuation of anterolateral borders
of carapace; anterolateral borders dentate with
denticles more prominent than in H. pudibundus.
middle denticle of each tooth projecting.

Chelipeds moderately strong; carpus and hand
with lines of coarse tubercles on outer face and a

three- to four-toothed crest on superior margin of
hand. Dactyls of walking legs with a coating of
short, dense pubescence except for tip and a nar-
row smooth line on each side.

Measurements. — Carapace of male: length, 46
mm. ; width, 67 mm.

Variations. — In a series representing various
ages a great deal of variation is shown, the granu-
lations being relatively much coarser and the
spots more numerous and variable in color in
juveniles.

Color. — Dark gray or brownish with numerous,
rather large, round or irregular spots of light red
(muddy lavender to light red in young) with
darker borders scattered over carapace.

Habitat. — This species is often found in depths
of a few fathoms in channels of Beaufort, N.C.,
harbor, though such individuals are not so numer-
ous or large as those taken in the ocean outside.
Gunter (1950) found the species in water ranging
from 28.7 to 35.2 %0 . Two to 25 fathoms.

Type locality. — Carolina.

Known range. — Chesapeake Bay to Gulf of
Campeche, Mexico; Cuba; Jamaica; Dominican
Republic.

Remarks. — Though recorded in depths to 25
fathoms, Hildebrand (1954, 1955) found this spe-
cies most common shoreward of 12 fathoms in

Figure 140. — Hepatus epheliticus (Linnaeus). Male in
dorsal view, legs of left side not shown, 20 mm. indi-
cated.

158

FISH AND WILDLIFE SERVICE

Texas and Mexico. He found ovigerous females
rare, but occurring in July, and noted a common
occurrence of the sea anemone, Calliactis tricolor,
on the carapace, as found also by Carlgren and
Hedgpeth (1952).

Gray (1957) found that H. epheliticus has a
large gill area in relation to its weight. He related
this large respiratory area to its active nature as
compared to other strictly aquatic crabs.

Costlow and Bookhout (1962b) described five
zoeal and one megalops stage from individuals
hatched and reared at 25° C. in an array of salini-
ties ranging from 20 to 40 °/00 . Complete de-
velopment took place only at 30 and 35 °/00
though some growth occurred in the other salini-
ties. The authors pointed out that the adults are
usually found in waters with salinity in the 30-35
%o range.

Genus Osachila Stimpson 1871

Ratbbun, 1937, p. 248. — Hemming, 1958b, p. 17.

KEY TO SPECIES IN THE CAROLINAS

a. Posterolateral margin of carapace thin edged, almost

sharp tuberosa (p. 159).

aa. Posterolateral margin of carapace thick, blunt

semilevis (p. 159).

Osachila tuberosa Stimpson

Figure 141

Osachila tuberosa Stimpson, 1871a, p. 154. — Hay and Shore,
1918, p. 423, pi. 31, fig. 10.— Rathbun, 1937, p. 250, pi. 77,
flg. 3 (rev.).

Figure 141. — Osachila tuberosa Stimpson. Male in dorsal
view, 3 mm. indicated.

Recognition characters. — Carapace octagonal,
with six large protuberances, one mesogastric,
paired metagastric, one cardiac, paired mesobran-
chial; protuberances and lateral margins finely
eroded. Anterolateral margins finely dentate,
continued toward buccal cavity; posterolateral
margins thin edged, with four lobes, first lobe
projecting sideways slightly beyond adjacent
anterolateral tooth. Front usually with a narrow
sinus. Maxillipeds, sternum, abdomen, and bases
of legs eroded.

Chelipeds short, thick, tuberculate on outer
face, and with rough margins; hand stout, upper
margin with three teeth, proximal one bifid; im-
movable finger thick. Walking legs more or less
prismatic with sharp margins and light longi-
tudinal grooves.

Measurements. — Carapace of female: length, 18
mm. ; width, 20 mm.

Color. — "Sand color with reddish cast, white
below, claws and legs white." (Henderson in
Kathbun,1937.)

Habitat. — Forty to 65 fathoms.

Type locality. — Five stations among the
Florida reefs, 36-68 fathoms.

Known range. — Off Cape Hatteras, N.C., to
west Florida.

Remarks. — This southern species has been re-
corded only once from North Carolina.

Osachila semilevis Rathbun

Figure 142

Osachila semilevis Rathbun, 1916, p. 652, pi. 36, flg. 1. — Hay
and Shore, 1918, p. 422, pi. 31, flg. 9.— Rathbun, 1937, p. 251,
pi. 77, fig. 1 (rev.).

Recognition characters. — Much like O. tu-
berosa. Carapace octagonal, with six large pro-
tuberances, one mesogastric, paired metagastric,
one cardiac, paired mesobranchial ; protuberances
eroded, depressions nearly smooth. Anterolateral
margins finely dentate, continued toward buccal
cavity; posterolateral margins thick, with four
lobes; first lobe not projecting laterally so far as
adjacent anterolateral lobe; last lobe quite promi-
nent. Front usually with a narrow buttonholelike
sinus.

Chelipeds short, thick, tuberculate on outer face
and with rough margins; hand stout, upper mar-
gin with three simple teeth; immovable finger
thick, dactyl comparatively slender and straight.
Walking legs of moderate size, more or less

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

159

Figube 142. — Osachila semilevis Rathbun. Animal in dor-
sal view, 3 mm. indicated.

prismatic and lightly grooved. Abdomen narrow,
eroded along margins and on last two sejgments.

Measurements. — Carapace of ovigerous female:
length, 13 mm. ; width, 15 mm.

Habitat. — Thirteen to 50 fathoms.

Type locality. — Gulf of Mexico, 25 fathoms.

Known range. — Off Beaufort, N.C., to north-
west Florida.

Remarks. — This southern species has been re-
corded north of Florida only twice, both times
from the Beaufort, N.C., area. Ovigerous females
have been taken from Florida in July.

Subsection Brachygnatha

Brachyura having buccal frame roughly quad-
rate. Last pair of legs normal in form, rarely re-
duced in size, and almost never dorsal. Gills few.
First abdominal appendages of female absent, fe-
male openings sternal.

Superfamily Brachyrhyncha

Fore part of body broad, rostrum reduced or
absent; body oval, round, or square, usually
broader than long. Orbits nearly always well en-
closed.

Family Portunidae. The swimming crabs

Crabs with body transversely oval, usually five
to nine lateral teeth. Last pair of legs usually dis-

tinctly adapted for swimming, with terminal
article ovate, flattened.

The family has a fossil record in America dat-
ing from the Cretaceous (Rathbun, 1935).

Stephenson and Campbell (1960) discussed the
status of portunid subfamily names in the light of
recent action by the International Commission on
Zoological Nomenclature. This decision altered
the usage of Rathbun (1930a) in that the sub-
families Liocarcininae and Thalamitinae become
respectively Macropipinae and Portuninae.

KEY TO GENERA AND SOME SPECIES IN THE
CAROLINAS

a. Carapace with five teeth of about equal size on antero-
lateral margin; interocular teeth three (Subfamily

Macropipinae) Ovalipes (p. 160).

aa. Carapace with nine anterolateral teeth, lateral tooth
usually much larger than others ; interocular teeth
four, six, or eight ( Subfamily Portuninae).
b. Movable portion of antenna not excluded from orbit,
c. Palate with longitudinal ridge.

d. Abdomen of male more or less triangular

Port units (p. 162).
dd. Abdomen of male with last two segments
much narrower than basal segments

CalUnectes (p. 168).
cc. Palate without logintudinal ridge

Arcmicus cribrarius (p. 173).

bb. Movable portion of antenna excluded from orbit by

prolongation of basal article; anterolateral teeth

alternately large and small Cronius ruber (p. 174).

Subfamily Macropipinae
Genus Ovalipes Rathbun, 1898

Rathbun, 1930a, p. 18.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace yellowish gray, closely set With small annu-
lar spots of reddish purple ; iridescent spots between
each pair of anterolateral spines approximately alike
in size and shape ocellatus (p. 160.)

aa. Carapace yellowish gray, without ocellated spots ;
iridescent spot between fourth and fifth anterolateral
spines large and nearly semicircular in shape

guadulpen-sis (p. 161).

Ovalipes ocellatus (Herbst)

Figure 143

Cancer ocellatus Herbst, 1799, p. 61, pi. 49, flg. 1.
Ovalipes ocellatus ocellatus: Hay and Shore, 1918, p. 426,
pi. 32, flg. 7. — Rathbun, 1930a, p. 19, pis. 2-3 (rev.).
Ovalipes ocellatus: Williams, 1962, pp. 39-41.

Recognition characters. — Carapace about one-
fourth wider than long, convex, finely granulate

160

FISH AND WILDLIFE SERVICE

Figure 143. — Ovalipes ocellatus (Herbst). Male in dor-
sal view, approximately X 0.80 (after Ratnbun, 1884).

overall except for longitudinal band of slightly
enlarged granules in median line and smooth area
on posterior central portion of adults. Front with
three acute teeth, median one about twice as long
as lateral ones. Orbit with a shallow fissure above,
often nearly closed in adults, open in young. Five
anterolateral teeth strong, acute, directed for-
ward; inner suborbital angle projecting at least
as far as median frontal tooth. Pterygostomian
region with a long, curved, stridulating ridge
made up of approximately 50 close-set striae nar-
rowing into tubercles at inner end of ridge, a
short complementary ridge on proximal end of
inner margin of merus ; lobe at distal inner angle
of merus of outer maxilliped longer than broad.

Chelipeds rather large; distal three-fifths of
anterior margin of merus with several small
spines and a dense fringe of hair; carpus with
two spines, inner one very long; hand triangular
in section, external border cost ate, covered with
uniform small tubercles, internal border with an
overhanging densely hairy ridge ending distally
in a sharp spine, ridges and internal line of hairs
continued on dactyl; fingers about as long as
palm, tapering gradually, tips turned abruptly
toward each other.

Abdomen of male narrow, sides nearly parallel;
sixth segment nearly twice as long as seventh in
midline, seventh segment subcircular; first pleo-
pods of male broad and stout in proximal two-
thirds, narrowing abruptly distally and with
terminal portion bent ventrolaterally in a sinuous
curve. Abdomen of adult female suboval and
small compared to sternum.

Measurements. — Carapace: males, length, 64
mm., width, 77 mm.; female, length, 39 mm.,
width, 48 mm.

Variations. — Spines are more acute on young
than on old individuals, and on some old adults
the anterolateral spines are worn away leaving
only rounded humps. The orbital fissure is nearly
closed in adults but often open in young indi-
viduals. The width between the suborbital angles
tends to increase relatively with age.

Color. — "Yellowish gray, closely set with small
annular spots of reddish purple; carapace and
chelipeds with a silvery or brassy iridescence;
ground color of chelipeds and legs light brownish
tending to orange and bluish ; large irregular blu-
ish purple spots on upper surface of chelipeds;
large part of carpus including spine bluish ; simi-
lar but lighter spots on proximal half of other
legs; paddles greenish yellow, with deep yellow
rim" (Eathbun, 1930a, and other authors). An
iridescent spot between each pair of anterolateral
spines.

Habitat. — Common on a variety of bottoms,
especially sand ; surface to 18 fathoms.

Type locality. — Long Island near New York.

Known range. — Prince Edward Island, Canada
(E. L. Bousfield, personal communication), to
Charleston, S.C., and on Texas coast jetties
(Whitten, Rosene, and Hedgpeth, 1950).

Remarks. — The distinctions between this spe-
cies and 0. guadulpensis were discussed by Wil-
liams (1962). There is a distinct color difference,
pointed out in the color descriptions, and an ap-
parent difference in habitat among the adults.
Adults of 0. ocellatus are found near shore in the
Carolinas where the young of both species are also
found, as pointed out by a number of authors.

Pearse, Humm, and Wharton (1942) pointed
out that 0. ocellatus can bury itself completely in
sand and respire by passing water into the gill
cavity from anterior lateral openings, then out
through two posterior openings. Gray (1957) cor-
related great activity of the species with large gill
area and compared this with gill areas of other
strictly aquatic crabs.

Ovalipes guadulpensis (Saussure)

Portunus guadulpensis Saussure, 1858, p. 433, pi. 2, fig. 10.

Ovalipes ocellatus floridanus Hay and Shore, 1918, p. 427,
pi. 32, fig. 8.

Ovalipes ocellatus guadulpensis: Rathbun, 1930a, p. 23, pi. 4
(rev.).

Ovalipes guadulpensis: Williams, 1962, pp. 39-41.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

161

Recognition characters. — Closely resembling 0.
ocellatus, but differing in the following char-
acters : dorsal aspect of carapace not covered with
ocellated spots; body flatter than 0. ocellatus, and
carapace evenly granulate overall except for
smooth area on rear central portion; outer orbital
and frontal teeth more acute than in 0. ocellatus,
median frontal tooth acuminate; iridescent spot
between fourth and fifth anterolateral spines
larger than spots between first to fourth teeth and
nearly semicircular in shape; external ridge on
palm of chelipeds with tubercles not uniform in
size giving a roughened appearance in individuals
larger than 30 mm. in width.

Measurements. — Carapace: male, length, 67
mm., width, 82 mm.; female, length, 56 mm.,
width, 67 mm.

Variations. — The distance between the sub-
orbital angles tends to increase relatively with
age.

Color. — "General color of carapace light lav-
ender gray underlaid with dull yellow, some
specimens darker or lighter, with a regular pat-
tern of lighter spots dull yellow, off white, or
bluish yellow to lavender yellow, rear border of
carapace light blue; spines of carapace purplish
red at base to red or purple subdistally, white at
tips; carpus and merus of chelipeds somewhat
same color as carapace except pink flesh colored
at carpo-meral joint and on hand; fingers white
on inner surface, and with white teeth ; large spine
at internal angle of carpus and a few small but
distinct spots on superoexternal surface of hand
purple, large spine grading to lighter purple on
body of carpus; anterior border of chela and first
three pairs of walking legs with a longitudinal
band of brownish purple, band extending to
lower border of dactyl on chela; dactyls of first
three walking legs and outer border of hand im-
mediately below external ridge, same color, some-
times darker on dactyl with teeth same color,
distal tip of immovable finger similarly colored;
blade of swimming leg yellowish; underparts
light.

"Iridescent spots between anterolateral teeth,
on distal or dorsal surface of external carpal spine
and along upper edge of hand, at superodistal
corner of merus on first three walking legs and
along dorsal edge of first three pairs of walking
legs distally, or dorsal surface of second abdom-

inal segment; spot between fourth and fifth an-
terolateral spines nearly semicircular" ("Williams,
1962).

Habitat. — Taken on sandy bottom in the Caro-
linas and from similar bottoms elsewhere, accord-
ing to literature records; surface to 49 fathoms
( rarely to 925 fathoms ? ) .

Type locality. — Guadeloupe.

Known range. — Cape Hatteras, N.C., to Port
Aransas, Tex. ; Guadeloupe ; Brazil.

Remarks. — The distinctions between this spe-
cies and 0. ocellatus were discussed by Williams
(1962). There is a distinct color difference,
pointed out in the color descriptions, and an ap-
parent difference in habitat among the adults.
Adults of 0. guadulpensis are found farther from
shore than adults of 0. ocellatus in the Carolinas,
but the young of both species are found near
shore, as pointed out by a number of authors.

Ovigerous females are known from North Caro-
lina in January.

Subfamily Portuninae
Genus Portunus Weber, 1795

Rathhun. 1930a, p. 33. — Hemming, 1958b, p. 133. — Stephenson
and Campbell, 1959, p. 85.

Stephenson and Campbell (1959) gave a num-
ber of arguments for and against the utility of
subgeneric limitations within this genus as now
understood. Though subgeneric subdivisions may
be useful in the limited Carolinian fauna, they are
being deleted here.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace wide ; anterolateral margins forming arc of
a circle with center near posterior margin of carapace,
b. Interocnlar teeth six, inner orbital tooth being entire,
c. Carapace convex, mostly smooth and glossy ; palms
swollen, only one spine on upper margin in addi-
tion to spine at base of dactyl sayi (p. 163).

cc. Carapace uneven, not smooth and glossy ; two
spines on upper margin of palm in addition to

spine at base of dactyl anceps (p. 163).

bb. Interocular teeth eight, inner orbital tooth being

bilobed gibbcsii (p. 164).

aa. Carapace narrow ; anterolateral margins forming are
of a circle with center near middle of cardiac region,
b. Interocular teeth eight, inner orbital tooth being

bilobed spininuinns (p. 165).

bb. Interocular teeth six, inner orbital tooth being en-
tire or notched laterally.

c. Superoexternal surface of chela with a conspicu-
ous, smooth, silvery, or iridescent area

(trdirayi (p. 166).

162

FISH AND WILDLIFE SERVICE

cc. Superoexterual surface of chela ridged and not
iridescent.

d. Last pair of legs with posterodistal margin of
merus unarmed ; upper margin of dactyl con-
spicuously fringed with long hairs

deprcssifrons (p. 163).
dd. Last pair of legs with posterodistal margin of
merus armed with spinulous lobe ; carpus of
cheliped with inner spine greatly elongated

sp in ioa rp us (p. 167 ) .

Portunus sayi (Gibbes)

Figure 144

Lupa sayi Gibbes, 1850, p. 178.

Portunus sayi: Hay and Shore, 1918, p. 428, pi. 33, fig. 2. —
Rathbun, 1930a, p. 37, text-figs. 6-7; pi. 14 (rev.).

Recognition characters. — Carapace nearly
twice as wide as long, somewhat tumid, smooth
and polished to naked eye, finely granulate under
magnification. Six frontal teeth including inner
orbitals, two submedian teeth smaller but on a
line with next pair. External orbital tooth larger
than those of anterolateral border except stout,
acute ninth; remaining anterolateral teeth blunt
and increasing slightly in size posteriorly.

Chelipeds of moderate length, somewhat larger
in males than in females ; merus with four, rarely
three, stout, curved spines in front, none behind ;
carpus with two spines ; hand with an acute spine
at articulation and a smaller one near base of
movable finger; external surface with two longi-
tudinal ribs with lowermost extending on finger;
superior surface with three ribs continuing on
finger, innermost one with fringe of hair beneath.

Figure 144. — Portunus sayi (Gibbes). Animal in dorsal
view, legs of left side not shown, 20 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Measurements. — Carapace: male, length, 27
mm. ; width, 53 mm.

Color. — Chocolate brown or purplish with
cloudings of olive green or light brown and ir-
regular white or flesh-colored spots; orange mar-
gins on spines of chelipeds.

Habitat. — Normally this is a pelagic form liv-
ing among floating Sargassum, but it is often
carried into Beaufort Inlet, N.C., by currents.

Known range. — North Atlantic Ocean from
Nova Scotia south through Gulf of Mexico to
Brazil; mid-Atlantic Ocean; Bermuda; Kergue-
len Island, south Indian Ocean.

Remarks. — The species has a fossil record dat-
ing from the lower Miocene of North America
(Rathbun, 1935).

Ovigerous females are known from April to
August in the southeastern United States and in
parts of the West Indies. They are also known
from Culebra in February and near Nantucket in
September (Rathbun, 1930a, in part). Some of
the larval stages were described by Lebour (1944)
at Bermuda. Coventry (1944) gave new records
for the Bahamas in addition to those listed by
Rathbun (1930a).

Portunus anceps (Saussure)

Figure 145

Lupea anceps Saussure, 1858, p. 434, pi. 2, figs. 11-llb.
Portunus anceps: Hay and Shore, 1918, p. 431, pi. 33, fig. 8. —
Rathbun, 1930a, p. 42, pi. 15 (rev.).

Recognition characters. — Carapace twice as
wide as long, pubescent, and with several indis-
tinct, arching, granulate, transverse ridges. Six
frontal teeth including inner orbitals, inner orbi-
tals blunt and considerably shorter than outer
pair of true frontal teeth, submedian teeth short,
smaller than inner orbitals. Anterolateral teeth
small, acute, curved forward, last one sharp,
slender, and about as long as space occupied by
four preceding teeth.

Chelipeds long; merus with four spines in
front, a distal one behind; carpus ridged, with a
strong internal and a smaller external spine;
hand with ridges on outer and superior surfaces,
most of ridges continuing on fingers, superoin-
ternal ridge more elevated than others, ending
distally in two spines, one behind other.

Measurements. — Carapace: male, length, 13
mm., width, 26 mm. ; ovigerous female, length, 15
mm., width, 29 mm.

163

fe LIBRARY )£]

Figure 145. — Portunus anceps (Saussure). Male in dor-
sal view, legs of left side not shown, 5 mm. indicated.

CoZor.— Mottled gray and yellowish white so as
to imitate sand; first pair of legs red or yellow;
chelipeds and other legs same color in part (Ver-
rill, 1908). Hairs on legs colorless (Abramowitz,
1935).

Habitat. — This form lives on or near sandy
shores in tropical waters, but is sometimes carried
northward in the Gulf Stream to the North Caro-
lina capes; surface to 40 fathoms.

Type locality. — Cuba.

Known range. — Cape Hatteras, N.C., to Brazil ;
Bermuda.

Remarks. — Rathbun (1930a) recorded ovige-
rous females from June in Cuba to October in
North Carolina.

Portunus gibbesii (Stirapson)

Figure 146

Lupa gibbesii Stlmpson, 1S59, p. 57.

Portunus gibbesii: Hay and Shore, 1918, p. 428, pi. 33, fig. 1. —
Rathbun, 1930a, p. 49, pis. 16-17 (rev.).

Recognition characters. — Carapace approxi-
mately twice as wide as long, not tumid, thickly
covered with small spherical granules, pubescent,
and with three or four naked, transverse ridges,
two of which arise from lateral spines and run
toward gastric region. Eight frontal teeth includ-
ing two points of each inner orbital, median pair
of frontal teeth narrower and slightly more ad-
vanced than next pair. External orbital tooth not
much larger than teeth of anterolateral border,
these latter stout, acute, directed forward; last
tooth, or lateral spine, slender, sharp, curved for-
ward and about as long as space occupied by three

preceding teeth. One or more small, naked, irides-
cent areas near anterolateral margin at base of
teeth.

Chelipeds long, slender; merus with five to
seven spines in front, and one behind at distal
end; carpus with a large internal and a smaller
external spine; hand slender, ribbed on all sur-
faces ; ribs continued on fingers and roughened by
sharp-pointed, appressed tubercles; hand with
two spines, one at articulation with carpus, an-
other near distal end of superior rib; fingers
nearly straight with incurved tips.

Measurements.— Carapace : male, length, 29
mm.; width, 61 mm.

Color. — Brownish red, transverse ridges on
carapace, spines, and margins of chelipeds car-
mine red ; front side of legs brilliantly iridescent
by lantern light, iridescence evident to some ex-
tent in preserved material.

Habitat. — The species is fairly common about
the Beaufort, N.C., region and is often taken in
deeper channels of the harbor. Along with P.
spinimanus. Hildebrand (1955) reported this spe-
cies as common on the shrimping grounds on
Campeche Bank in the Gulf of Mexico, but rare
on the Texas coast, Surface to 48 fathoms, rarely
deeper.

Type locality—South Carolina and St. Augus-
tine, Fla.

Known range.— Southern Massachusetts to
Texas; Venezuela; Surinam.

Figure 146. — Portunus gibbesii (Stimpson). Male in
dorsal view, legs of left side not shown, 10 mm.
indicated.

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FISH AND WILDLIFE SERVICE

Remarks. — Ovigerous females have been re-
ported and are otherwise known to occur in the
months February to June from North Carolina
to Surinam (Holthuis, 1959; Kathbun, 1930a).

Gray (1957) computed gill area per unit weight
for P. gibbesii as intermediate among a number
of swimming crabs studied.

Portunus spinimanus Latreille

Figure 147

Portunus spinimanus Latreille, 1819, p. 47. — Hay and Shore,
1918, p. 429, pi. 33, fig. 4. — Rathbun, 1930a, p. 62, text-fig. 10,
pis. 26-28 (rev.).

Recognition characters. — Carapace considera-
bly less than twice as wide as long, finely granu-
late and pubescent, with a number of prominent,
curved, coarsely granulate, transverse ridges.
Eight frontal teeth, including inner orbitals, each
notched at summit and presenting two points;
median pair of teeth slightly narrower and more
advanced than next pair, all considerably more
advanced than inner orbitals. Outer orbital teeth
obtuse, not much larger than teeth of anterolat-
eral borders, these latter strong, acute, or acumi-
nate, about equal in size except last; this tooth
about twice as large as others and usually curved
forward.

Chelipeds long, pubescent, serratogranulate all
over; merus with four, occasionally five, strong,
curved spines in front and one at distal end ; car-
pus with two spines, inner one much stronger,
and with four conspicuous ridges on upper sur-
face ; hand slender, all surfaces with ridges which
extend on fingers ; a strong spine at carpal articu-
lation and another near base of dactyl; fingers
nearly straight, tips incurved.

Measurements. — Carapace: female, length, 55
mm.; width, 88 mm.

Variations. — Large males have relatively
longer, thinner chelipeds and longer walking legs
than large females.

Color. — Pubescence yellowish or reddish brown,
ridges of carapace, spines of chelipeds, fingers
and tips of legs reddish brown; anterolateral
teeth reddish at base, white at tips; merus, carpus,
and hand of chelipeds with white blotches.

Habitat. — This species is common in the waters
off Beaufort Inlet, N.C., and is sometimes found
in deeper channels of the harbor. P. gibbesii is

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 O— 65 12

Figure 147. — Portunus spinimanus Latreille. Male in
dorsal view, legs of left side not shown, 20 mm.
indicated.

often found in company with P. spinimanus. A
similar association of these two species was re-
ported by Hildebrand (1955) for the Campeche
Banks in the Gulf of Mexico where they are com-
mon. On beach under Sargassum; surface to 50
fathoms.

Type locality. — American waters, common in
Brazil.

Knoion range. — New Jersey through Gulf of
Mexico and West Indies to southern Brazil ; Ber-
muda.

Remarks. — This species, which somewhat re-
sembles P. gibbesii, can be readily distinguished
from the latter by its narrower, rounder form, and
by the entire lack of iridescent patches on the
carapace mentioned for P. gibbesii.

Ovigerous females are known from January to
July in Florida (Wass, 1955, in part) ; March in
Campeche ; April in Isle of Pines ; May, August,
and September in Surinam (Holthuis, 1959) ; and
July in St. Thomas, V.I. (Rathbun, 1930a). Le-
bour (1950) found an ovigerous female among
Sargassum in Bermuda in May, and from the
eggs reared larvae which she illustrated.

Gray (1957) computed gill area per unit weight
for P. spinimanus as intermediate among a num-
ber of swimming crabs studied.

165

Portunus ordwayi (Stimpson)

Figure 148

Achelous ordwayi Stimpson, 1860a, p. 224.
Portunus ordwayi: Hay and Shore, 1918, p. 431, pi. 33, fig.
Rathbun, 1930a, p. 71, pi. 33 (rev).

FiGintE 148. — Portunus ordwayi (Stimpson). Male in
dorsal view, legs not shown except for right cheliped, 10
mm. indicated.

Recognition characters. — Carapace approxi-
mately 1.5 times as wide as long, uneven, eleva-
tions granulate and depressions pubescent, with
a number of conspicuous, curving, transverse
ridges. Six frontal teeth including acuminate in-
ner orbitals; true frontal teeth about equal in
size, triangular, acute, middle pair advanced be-
yond others. Outer orbital tooth large; antero-
lateral teeth diminishing slightly in size from first
to seventh, inclusive, eighth about as long as space
occupied by two preceding teeth, tips of all acute
and turned forward.

Chelipeds of moderate length ; merus with four
or five strong spines in front, a single distal one
behind; carpus ribbed and with strong internal
and much smaller external spine; hand ribbed on
all surfaces except flat, highly iridescent, superior
surface; superointernal ridge raised into a crest
terminating (list all v in a sharp spine. Margins of
carapace and rhelipeds more or less fringed witli
silky hairs.

Mi -ii.tn n in i -nfs. — Carapace: male, length, 26
mm.; width, 42 mm.

Color. — Carapace and legs reddish brown due
to fine mottling with red, yellowish brown, and

gray; pale orange beneath, deeper orange on
chelipeds and legs; chelae deep red brown above,
fingers with two cross bands of light orange red.
Blue coloration also apparent near red and dark
pigments; hairs on appendages deep red (Abram-
owitz, 1935).

Habitat. — This is another of the tropical swim-
ming crabs which move northward with warm
water currents; surface to 58 fathoms, rarely
deeper.

Type localities. — Key Biscayne and Tortugas,
Fla.; St. Thomas, [V.I.].

Known range. — Vineyard Sound, Mass. ; North
Carolina through Gulf of Mexico, Caribbean Sea,
and West Indies to State of Bahia, Brazil ; Ber-
muda.

Remarks. — Rathbun (1930a) listed an ovige-
rous female in March from Florida.

Portunus depress if rorts (Stimpson)

Figure 149

Amphitrite deprcsifrons Stimpson, 1859, p. 58.
Portunus depressi/rons: Hay and Shore, 1918, p. 430, pi. 33,
fig. 7.— Rathbun, 1930a, p. 84, pi. 41 (rev.).

Recognition characters. — Carapace approxi-
mately 1.6 times as wide as long, uneven, pubes-
cent, and with indistinct transverse ridges. Six
frontal teeth, including inner orbitals much larger
than others, tips of all teeth about on a line. Ex-
ternal orbital tooth strong, tip rounded; antero-
lateral teeth acute, turned forward, lateral tooth
scarcely longer than one in front, teeth and inter-
vals between them fringed with hairs.

Chelipeds trigonal, serratogranulate and pubes-
cent; merus with five spines in front and a distal
one behind; carpus with two spines, outer much
smaller than inner one; hand short and com-
pressed, upper margin raised into a crest termi-
nating distally in a stout spine, a smaller spine at
carpal articulation; fingers flattened, dactyl with
border of hairs on superior margin. Walking legs
unusually long and slender, first pair with articles
fringed with hairs. Swimming legs shorter than
in most species of genus.

Miiixiireincrit-s. Carapace: male, length, 26
mm.; width, 41 mm.

Color. — Carapace in life irregularly mottled
witli light and dark gray, closely imitating colors
of sand; chelipeds and posterior legs similar,
though paler; first pair of walking legs bright

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FISH AND WILDLIFE SERVICK

Figure 149. — Portiinus depressifrons Stimpson. Male
in dorsal view, legs of left side not shown, 10 mm.
indicated.

purple, or deep blue in larger specimens, while
some portion of same color usually apparent on
next two pairs, but color of first pair in striking
contrast with rest of crab. Very young speci-
mens do not show this distinction in color of legs,
so far as observed (Verrill, 1908).

Habitat. — Abundant in shallow water on sandy
bottoms of coves and inlets at Bermuda (Verrill,
1908) ; surface to 16 fathoms.

Type localities. — South Carolina and Florida
Keys.

Known range. — Fort Macon, N.C. (Coues and
Yarrow, 1878; Kingsley, 1880) to Gulf of Cam-
peche and Caribbean Sea; Bermuda.

Remarks. — This crab has not been collected in
the Carolinas for many years, so far as recorded.
Records in the U.S. National Museum show no
specimens from farther north than Key West,
Fla., and the Bahamas near the southeast coast
of the United States. A number of specimens in
the U.S. National Museum collection were taken
from the stomachs of the gray snapper, Lutjanus
(=Neamaenus) griseus, the yellow goat fish, Mul-
loidichthyes (=Upeneus) martinicus, and other
predaceous fish. Rathbun (1930a) reported ovi-
gerous females in June from Florida, and in
August from Florida and the Caribbean. More
recently, egg-bearing females have been taken on
Campeche Banks in late August.

Portunus spinicarpus (Stimpson)

Figure 150

Achelou8 spinicarpus Stimpson, 1871a, p. 148.
Portunus spinicarpus: Hay and Shore, 1918, p. 429, pi. 33,'
fig. 3.— Rathbun, 1930a, p. 92, pi. 46.

Recognition characters. — Carapace slightly
more than twice as wide as long, sculptured, with
a number of naked, rather coarsely granulate,
arching, transverse ridges separated by finely
granulate and pubescent surfaces. Six frontal
teeth, including inner orbitals, with sinuate but
unnotched outer margins; true frontal teeth nar-
row, acute, separated by broad notches, median
pair considerably advanced beyond others. Ex-
ternal orbital tooth acute, larger than neighbor-
ing teeth of anterolateral margin; latter varying
somewhat in size, concave sided, acute; lateral
tooth with form of slender curving spine more
than half as long as anterolateral border; poster-
olateral angle sharp, margin slightly recurved.

Chelipeds long, slender; merus with four or
five stout, curved spines in front, and a single,
similar, distal spine behind. Carpus with two
spines, outer one small and weak, inner one long,
extending along side of hand to near base of dac-
tyl. Hand with serratotuberculate ridges, pro-
longed on fingers, and two spines, one at carpal
articulation, another near base of movable finger.
Fingers nearly straight, incurved at tips.

Measurements. — Carapace: male, length, 18
mm. ; width, 38 mm.

Variations. — Rathbun (1930a) stated that ovi-
genous females are smaller than males, and their
chelipeds are shorter, with the carpal spine not
reaching beyond the superior spine of the hand.
The lateral spine is relatively longer in young
than in old individuals and changes in angle of
projection with age, extending straight laterally
or slightly backward in the young, but curving
slightly forward in mature individuals.

Color. — Carapace buff pink, mottled, highest
ridges touched with cinnamon red; fingers bor-
dered with crimson and maroon; two basal teeth
of dactyl and margin of palm white; rest of chela
maroon purple and purplish red, same color on
fringe of hair on carpal spine ; walking legs pur-
ple. (Schmitt in Rathbun, 1930a, where great,
detail on younger individuals is given.)

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

167

Figure 150. — Portunus spinicarpua (Stimpson). A, male
in dorsal view, legs not shown except for right cheliped :
B. right chela of male in frontal view ; 5 mm. indicated.

Habitat. — This appears to be a species living in
deeper waters of the region. On shrimping
grounds in the western Gulf of Mexico, Hilde-
brand (1954) reported it as found only along the
seaward side in depths of 15 to 37 fathoms. Five
to 300 fathoms.

Typt localities. — Off Tortugas, Carysfort Reef,
Conch Reef, Alligator Reef, Pacific Reef, and
American Shoal, Fla.; lat. 31°31' N. long. 79° 41'
W. off Georgia; in depths ranging from 13 to 150
fathoms.

Known range. — Off Cape Hatteras, N.C., to
State of Sao Paulo, Brazil.

Remarks. — Ovigerous females have been taken
from January to September from Florida to Suri-
nam, and in November in Texas. Pearse (1932b)
found the barnacle, Diehelastis sinvata Aurivil-
lius, on a number of individuals.

Genus Callinectes Stimpson, 1860

Rathbun, 1930a. p. 98.

KEY TO SPECIES IN THE CAROLINAS

a. Frontal teeth, including inner orbitals, four

sapidus i p 168 1

an. Frontal teeth, including inner orbitals, six

ornatus t\>. 172 i.

Callinectes sapidus Rathbun. Blue Crab
Figure 151

Lupa hastata Say, 1817, p. 65.

Callinectes sapidus Rathbun. 1896a, p. 352, pis. 12 ; 24, fig. 1 ;
25, fig. 1; 26, fig. 1; 27, fig. 1 (rev.).— Hay and Shore. 191S.
p. 432, pi. 35. fig. 1. — Rathbun, 1930a, p. 99, pi. 47 (rev.).

Recognition characters. — Carapace, including
lateral spines, 2.5 times as wide as long, moder-
ately convex, nearly smooth, except lightly tuber-
culate on inner branchial and cardiac regions; a
tuberculate transverse line from side to side be-
tween lateral spines, and a shorter transverse line
about halfway between this and frontal margin.
Four frontal teeth, including inner orbitals, tri-
angular, acute, both pairs more or less distinctly
bilobed. Anterior eight anterolateral spines of
subequal length, concave on both margins and
acuminate; lateral spines nearly straight, usually
longer than space occupied by three preceding
teeth ; inner suborbital tooth prominent and acute.

Chelipeds of male large and powerful, smaller
in female; merus with three spines in front and
one. small spine at distal end behind; carpus with
one spine and one spiniform tubercle on external
surface: hand strong, prominently ribbed, and
with a strong proximal spine; fingers nearly
straight and strongly toothed. Abdomen of male
in form of inverted T; basal segments broad, dis-
tal segments narrow; penultimate segment con-
stricted in proximal half, wider at both ends,
terminal segment approximately oblong-lanceo-
late ; first pleopods reaching nearly to, or beyond,
extremity of abdomen, approximated through
basal half, distal portions widely divergent except
at tips. Immature female with abdomen triangu-
lar; mature female with abdomen broad, rounded,
and lying loosely on ventral side of thoracic
sterna.

Measurements. — Width of carapace (including
spines): males, 200 mm.; females, 198 mm.;
smallest mature females (excluding dwarfs), 86
mm. Exceptional males in water of low salinity
may measure 230 mm., or more, in width.

Color. — Grayish, or bluish green of varying
shades and tints, relieved by more or less red on
spines of carapace; males with blue fingers on
hands, mature females with red fingers on hands;
underparts off white with tints of yellow and
pink. Churchill (1919) gave a colored frontis-
piece showing ventral and other views.

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FISH AND WILDLIFE SERVICE

Figure 151. — Callinectes sapidus Rathbun. Animal in dorsal view (after Rathbun, 1884).

Habitat, — Found on a variety of bottom types
in estuaries and shallow oceanic water; water's
edge to 20 fathoms.

Type locality. — [East coast of United States].

Known range. — Native recent range, Nova
Scotia (no longer endemic, Bousfield, personal
communication) to Uruguay ; Bermuda. The spe-
cies has been introduced in Europe, and was re-
ported from southwest France in 1901 ; from Hol-
land in 1932, 1934, and 1951; near Copenhagen,
Denmark, in 1951; in and near Venice, Italy, in
1949 and 1950; and in Israel in 1955. Holthuis
(1961) reviewed these occurrences in addition to
recently found well-established colonies in Tur-
key and Greece and remarked that the species
must now be regarded as indigenous to Europe.

Remarks. — There is a tremendous literature
concerning the blue crab, largely because of its
great economic value. Since it is not possible to
summarize this literature in a brief account such
as this, the interested student is referred to the
comprehensive bibliography compiled by Cronin,
Van Engel, Cargo, and Wojcik (1957) for a list of
the literature to that date, to excellent life history

and ecological summaries by Churchill (1919),
Truitt (1939), and Van Engel (1958) for the crab
in Chesapeake Bay; and to Darnell (1959) for
occurrence in Louisiana. Though these papers are
current and available, for the sake of convenience
certain essentials are reviewed here.

The fossil record for Callinectes sapidus reaches
back to the lower Miocene of Florida, and the
species has been found at later levels in Virginia,
Massachusetts, New Jersey, and the Carolinas
(Kathbun, 1935; Blake, 1953).

The spawning season on the east coast of the
United States is quite long. Females with yellow
egg masses attached have been found in North
Carolina from as early as March 21 to as late as
October 26. In that area, the greatest number of
females with eggs occur in spring, the time of
peak occurrence varying somewhat with season.
In Chesapeake Bay, the spawning season, with
rare exceptions, extends from late April to early
September with the peak occurring in June.
Farther south, on the coast of Texas the spawning
season extends from December to October and
may include November as well, but the peak oc-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

169

curs in June and early July (Daugherty, 1952).
Five stages in the reproductive cycle of mature
females have been described (Hard, 1942), and
a number of authors have shown that the number
of eggs in an egg mass (sponge) may range from
700,000 to more than 2 million.

The eggs hatch into zoeae, undergoing develop-
ment through seven stages. These stages have
been described from laboratory cultures (Cost-
low, Rees, and Bookhout, 1959; Costlow and
Bookhout, 1959). Atypically, an eighth stage may
occur. The last zoeal stage molts into a megalops
stage and this into the first crab stage.

Churchill found that eggs hatch in about 15
days at 26.1° C. and slightly faster at higher
temperatures. Development from hatching to
megalops lasts from 31 to a maximum of 49 days
in various salinities, but development time in the
different stages is quite variable even in a single
salinity-temperature combination. The megalops
stage lasts from 6 to 20 days. It was found that
development progresses at a comparable rate in
salinities between 20.1 and 31.1 °/0o at 25° C.
Salinity above 31.1 °/00 slowed development,
and below 20.1 °/00 larvae rarely completed the
first molt. Larvae never went beyond the first
zoeal stage when reared at 20° C. and did not
progress beyond the third zoeal stage when
reared at 30° C. Once the first crab stage is
reached, the animals continue to molt as they
grow and are estimated to undergo some 18 to 20
or more molts before reaching maturity (Van
Engel, 1958).

In Chesapeake Bay, where the crab is perhaps
more abundant than in other areas, it has been
demonstrated that crabs spawned in June of one
year are mature about 14 months later and at that
time mate. Most mating pairs are found in July,
August, or September, though the mating season
extends from May to October. At this time, fe-
males ready to molt into the mature stage (termi-
nal molt) are carried about, cradled upright,
under the males' bodies. Such pairs are called
doublers. The male frees the female during the
time she is actually casting the old exoskeleton,
but when this is shed he grasps her again, this
time with the ventral surfaces together, and com-
pletes the breeding act by introducing sperm via
the copulatory stylets into t he spermathecae.
Copulation may last for several hours. When

sperm transfer is complete, the female is allowed
to resume an upright posture and is again car-
ried under the male for a time until her shell is
hardened. Males may mate more than once and
at any time during their last three intermolts
(Van Engel, 1958) ; females only do so once, but
the sperm supply may serve to fertilize more than
one mass of eggs. Usually, a female mated in late
summer casts the first batch of eggs the following
spring at an age of approximately 2 years, but
egg laying may be at any time from 2 to 9 months
after mating. A second spawning has been ob-
served to occur later in summer among some indi-
viduals, and it is possible that a third may occur,
possibly as late as the succeeding spring or at an
age of 3 years. Three years is judged to be about
the normal maximum age for this species.

The life history of the blue crab is complicated
by the fact that it leads a migratory existence.
The migratory patterns have been studied in
greatest detail in Chesapeake Bay but the same
pattern appears to be true of other areas as well.
Mating usually takes place in water of reduced
salinity well up in estuaries. After this, the fe-
males migrate downstream to areas of higher
salinity near the mouths of estuaries where the
eggs are laid and hatched, whereas the males tend
to remain in the low-salinity areas for the re-
mainder of their lives. For this reason, samples
of adult crabs (or commercial catches) near the
sea contain greater numbers of females, whereas
those from the middle or upper reaches of bays
contain larger percentages of males except at the
breeding season. Once in the spawning areas, the
females tend to remain there for the remainder of
their lives or move a short way out 'to sea. Once
hatched, the zoeae lead a planktonic existence un-
til they transform to the megalops stage. As soon
as the crabs transform to the first crab stage, they
begin a migration up the estuary toward the mat-
ing grounds. Some early recruits may reach these
areas in their first summer of life, the remainder
early in the second year of life. In areas smaller
than Chesapeake Bay, there may be a certain
amount of overlap in mating and spawning
grounds but the two areas tend to be distinct. In
Chesapeake Bay, the spawning grounds are near
the mouth of the Bay; in North Carolina and
Louisiana, near the inlets and passes. In Texas,

170

FISH AND WILDLIFE SERVICE

most females with eggs are found in the Gulf
proper (Daugherty, 1952).

Aside from size variation associated with the
annual growth cycle, there is an apparent varia-
tion in size correlated with location in which the
animals are found (Van Engel, 1958). Though
never conclusively proved by experiments, it is
thought that there is a negative correlation of size
with the salinity in which a crab matures. Very
large males are probably large because they have
remained in water of low salinity. Fischler (1959)
reviewed the occurrence of "dwarf" ovigerous
females ranging in width from 52.3 to 80 mm.
All these specimens were taken near the sea, and,
as the author pointed out, may be small because
of environmental influences of high salinities
throughout life.

That the blue crab can tolerate fresh water is
well established. The subject is reviewed in some
detail by Odum (1953). On the basis of experi-
ment and observation he reached the conclusion
that oligohaline (100-1,000 p.p.m. CI) and nearly
oligohaline waters (25-100 p.p.m. CI) can be in-
vaded to a considerable extent if the crabs are
able to adjust slowly to the reduced chlorinity,
which, of course, is the case in natural invasions.
Many of the Florida streams and lakes are oligo-
haline and contain blue crabs, but in other areas
this is not true and blue crabs in such areas are
seldom found far from salt water.

Because the blue crab supports the largest crab
fishery in the United States, fluctuations in abun-
dance (especially in the Chesapeake area) have
been the subject of many conjectures and a num-
ber of investigations. Pearson (1948) dealt with
this subject at length. The fluctuations appear to
be associated with variable rates of survival in
the first year of life. No correlation was found
between relative abundance of female crabs and
their progeny. On the basis of examination of 13
generations, size of spawning stock did not deter-
mine size of population surviving to commercial
age at the rate of fishing prevailing during the
years studied. Pearson found evidence that exces-
sively cold weather may reduce availability of im-
mature and adult crabs either by direct mortality
or by making crabs less available to the fishery
immediately after the periods of cold weather.
Heavy runoff in some wet years may lower salin-
ity in the spawning areas enough to have an ad-

verse effect on survival of young, but such limits
are poorly understood.

Piers (1923) reported a population of blue
crabs in Nova Scotia, the recorded northern limit
for the species, and considered that it was a
natural rather than an introduced population.
Bousfield (personal communication) reports that
the species is certainly no longer endemic there.
Scattergood (1960) commented that fluctuations
in the population in Maine seemingly were corre-
lated with temperature when a series of warm
years accompanied an increase in number of blue
crabs.

The blue crab is often summarily dismissed as
a scavenger. Though it may be a scavenger, and,
indeed, is lured to crab pots or wire traps by
means of dead fish used for bait, students of the
feeding habits of the species agree that it is an
omnivore and prefers fresh to putrid flesh
(Churchill, 1919; Truitt, 1939; Van Engel, 1958).
Darnell (1961) showed that blue crabs in Lake
Pontchartrain, La., eat a variety of materials in-
cluding fishes, large and small bottom animals,
some vascular plant material, and organic detri-
tus. Of these materials, the category including
small bottom animals (e.g., those that are inti-
mately associated with the bottom) made up
about half of the diet. There are numerous notes
on feeding and predation in the literature record-
ing such habits as feeding on oysters, clams, and
tunicates.

In a study of gill area correlated with degree of
activity and habit of several species of crabs, Gray
(1957) found that the blue crab has a larger gill
area per gram of body weight than the other por-
tunids studied ( Ovalipes, Arenaeus, and Portunus
spp.) and, in fact, exceeded that of any crab
studied among aquatic, intertidal, and land crabs
in the Beaufort, N.C., area. The blue crab is
noted for its vigorous and pugnacious nature, and
this anatomical feature gives one reason for such
temperament.

Callineetes sapidus is fairly long-lived follow-
ing its last molt, and thus affords a lodging place
for barnacles and bryozoans. Its gills and gill
chambers become clogged with clusters of a small
stalked barnacle, Octolasmus lowei (Causey,
1961). The barnacles Balanus amphitrite and
Chelonibia patula attach to the carapace. The
sacculinid parasite, Loxothylacus texanus, lives

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

171

beneath the abdomen (Wass, 1955). Hopkins
(1947) discussed infestations of the parasitic ne-
mertean C arcinonemertes carcinophiJa on female
blue crabs showing that only light -colored worms
are found in the gills of mature females which
have never spawned. Large red worms are found
only on the gills of mature female crabs which
have spawned at least once, or in the gills and egg
masses of ovigerous females. Presence of large
red nemerteans in the gills is a sure sign that the
crab has spawned some time in the past. Pearse
(1932b) reported trematode metacercariae on the
gills.

Pigment in the melanophores of C. sajndus dis-
plays an endogenous rhythm with a frequency of
24 hours in the Gulf of Mexico where there is one
high and one low tide per day (Fingerman, 1955).
The pigment is in a dispersed state during the
day and in a contracted state at night. This cycle
is maintained under constant laboratory condi-
tions. Superimposed on the diurnal rhythm is a
tidal rhythm with a frequency of 12.4 hours. This
rhythm is manifested by a supplementary disper-
sion of melanin which occurs about 50 minutes
later each day and is most evident when the low
or high tide is either in the morning or late after-
noon. Under constant conditions, the phases bear
a definite relationship to times of low and high
tides in the native habitat. Also, there is evidence
for a semilunar rhythm. Only once every 14.8
days are the diurnal and tidal rhythms in the
same phases relative to each other.

Callinectes ornatus Ordway

Figure 152

CalUnectea ornatus Ordway, 1863, p. 571.— Hay and Shore,
1918, p. 433, pi. 34, fig. 2. — Rathbun, 1930a, p. 114, pi. 50
(rev.).

Recognition characters. — Carapace, including
lateral spines, slightly more than twice as wide as
long, somewhat tumid, finely granulate through-
out, transverse lines distinct, metagastric area less
than half as long as its anterior width. Six fron-
tal teeth including inner orbitals, submedial teeth
short, variable in length. Anterolateral teeth shal-
low and broad, tips of first five or six acute, others
acuminate; lateral spines curved forward,
scarcely as long as space occupied by three preced-
ing teeth; inner suborbital angle prominent.

Chelipeds shaped as in C. sa/>i<l>is. hut smaller,
with spines possibly more acute; ridges of hand

Figure 152. — Callinectes ornatus Ordway. Animal in
dorsal view, legs not shown, 10 mm. indicated.

more developed, and teeth on fingers relatively
larger and sharper. Abdomen of male with first
segment produced laterally into an acute, up-
turned spine.

Measurements— Carapace : male, length, 33
mm.; width, 74 mm.

Color. — Adult male: Carapace green dorsally,
irregular areas of iridescence at bases of, and be-
tween, anterolateral teeth, and on posterior and
posterolateral borders. Chelipeds and portions of
legs similar in color or more tannish green dor-
sally, with iridescent areas on outer and upper
edges of carpus and hands; chelae white on outer
face, blue to fuchsia on inner surface, with fuchsia
on tips of fingers and teeth of opposed edges.
Lateral spines and some anterolateral teeth, a,s
well as spines on chelipeds, white tipped. Walk-
ing legs grading from fuchsia distally through
violet blue to light blue mottled with white prox-
imally, pubescence on legs beige. Swimming legs
variably mottled with white; all legs with stellate
fuchsia markings at articulations. Under parts
white and blue.

Ovigerous female : similar to male except with
more violet blue on inner surface of chelae; fin-
gers either with white teeth or fuchsia-colored
teeth. Legs with dactyls reddish orange grading
abruptly to blue on propodi, pubescence brown
to beige. Abdomen with iridescent areas.

Habitat. — This crab, like its near relative, C.
sapidus, is a coastal species often found in estu-
aries, sometimes in fresh water. Brues (1927)
observed a large, active male that had been
trapped at the head of a Cuban tidal river in
fresh water during a dry period of about 3
months' duration. Lunz (1958), writing of a
form from the South Carolina crab fishery,

172

FISH AND WILDLIFE SERVICE

doubtfully referred to C. ornatus. said that it
tends to occupy oceanic waters and high- to
medium-salinity areas of estuaries chiefly in a
temperature range of 15° to 31° C, but has been
found in temperatures as low as 9° C. From over
500 trawl hauls in South Carolina, a depth maxi-
mum of 9 fathoms was found for the species.
However, specimens have been taken under a
light at night swimming at the surface in 925-
fathom water off the Mississippi River Delta
(U.S. National Museum notes).

Reported from surface to 40 fathoms, with
above exception.

Type localities. — Charleston Harbor [S.C.] ;
Tortugas [Fla.] ; Bahama Islands; Gonaives
[Haiti]; Cumana [Venezuela].

Known range. — New Jersey to State of Sao
Paulo, Brazil; Bermuda.

Remarks. — Blake (1953) reported a fossil rec-
ord for this species dating from the Pleistocene
of Maryland. Lunz (1958), in addition to habitat
data, reported ovigerous females from South
Carolina in May, August, and September, and
added that spawning probably takes place off-
shore. He found a sex ratio of approximately two
males to one female. Ovigerous females occur as
late as November in North Carolina.

Genus Arenaeus Dana, 1851

Rathbun, 1930a, p. 134. — Hemming. 1958b. p. 13.

Arenaeus cribrarius (Lamarck). Speckled crab

Figure 153

Portunus cribrarius Lamarck, 1818, p. 259.
Arenaeus cribrariux: Hay and Shore, 1918, p. 434, pi. 34, fig.
3. — Rathbun, 1930a, p. 134, pi. 58, figs. 2-3; pis. 59-60 (rev.).

Recognition characters. — Carapace more than
twice as wide as long, finely granulate, produced
on each side into a strong spine. Front not so far
advanced as outer orbital angles, with six teeth
including inner orbitals ; central tooth of each side
partly coalesced with adjacent submedian tooth.
Anterolateral teeth strong, somewhat acuminate,
heavily ciliate beneath. Superior wall of orbit
with two deep fissures dividing it into three lobes;
inferior wall of orbit with wide external fissure
and inner angle much advanced; lower surface
of carapace hairy.

Chelipeds of moderate size; merus with three
spines on anterior border, and a short tuberculi-
form one near distal end of posterior border;

carpus with two spines; hand short, with five
longitudinal granulose ridges and two spines, one
at articulation with carpus, another above base of
dactyl. Walking legs rather short and broad,
densely ciliate. Swiming legs stout. Basal seg-
ment of abdomen produced on each side into
strong, sharp, slightly upcurved spine.

Measurements. — Carapace: male, length, 48
mm,; width, 116 mm.

Color. — Light vinaceous brown or olive brown
thickly covered over dorsal surface with small,
rounded, white spots; spots on dorsal surface of
chelipeds somewhat larger; tips of walking legs
yellow. Color pattern persisting in alcohol.

Habitat. — As far as known, this crab seldom
enters estuaries and is rarely washed ashore
along the outer beaches. It lives in rather shallow
water close to the shore, and is well adapted to
life in the waves and shifting sand. Hildebrand
(1954) reported it as preferring the relatively
shallow water of the white shrimp grounds in
Texas. Siebenaler (1952) reported it as a "trash"
form on the Florida east coast shrimp grounds.
Waterline along beaches to 37 fathoms.

Type locality. — Brazil.

Known range. — Vineyard Sound, Mass., to
State of Santa Catarina, Brazil.

Remarks. — Ovigerous females are known in
August from Florida, and in September from
Venezuela and Brazil.

Figure 153. — Arenaeus cribrarius (Lamarck). Male in
dorsal view, legs not shown except for right cheliped,
color pattern of right side indicated, 50 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

173

Pearse, Humm, and Wharton (1942) stated
that where waves roll at the low-tide mark A.
cribrarius may scurry across sand and burrow
backward. In doing this, the crab flirts sand for-
ward away from the body with the chelipeds,
waves legs two to four rapidly from the median
line laterally, and moves the fifth legs posteriorly
and dorsally, thus sinking vertically into the sand.
Often the crabs bury themselves completely. The
heavy coat of hairlike setae on each side of the
mouth parts keeps out sand, and with the cheli-
peds held close to the body a clear channel is left
for currents from the branchial chamber. Ability
to maintain strenuous activity in the breaker zone
near shore may be partially explained also by
the relatively large respiratory surface in this
species (Gray, 1957).

Genus Cronius Stimpson, 1860

Rathbun, 1930a, p. 138.

Cronius ruber (Lamarck)

Figure 154
Portunu* ruber Lamarck, 1818, p. 260.
Cronius ruber: Rathbun, 1930a, p. 139, pis. 62-63 (rev.).

Recognition characters. — Carapace hexagonal,
smooth, pubescent ; a sinuous transverse ridge ex-
tending between lateral spines, and another

Figure 154. — Cronius ruber (Lamarck). Animal in dor-
sal view, legs of left side not shown ; ( redrawn from
Monod, 1956).

shorter, transverse, biarcuate ridge about halfway
between this ridge and front. Front proper with
four teeth, not including inner orbitals; sub-
median pair of teeth most advanced; second pair
more pointed, and directed slightly laterad, sepa-
rated from notched inner orbitals by a deep cut.
Orbit nearly circular. Basal article of antenna
with spine below insertion of movable portion.
Anterolateral teeth unequal, alternating large and
small; lateral spine not strikingly enlarged.

Chelipeds heavy; merus with four to six spines
in front, and with small distal spine behind; car-
pus with granulate ridges, one large internal
spine, and three small spines on outer surface;
hand with granulate ridges on all surfaces, armed
with four spines on superior surface, two on in-
ner and two on outer border.

Measurements. — Carapace: male, length, 50
mm. ; width, 75 mm.

Color.- — "Violet red or deep purple red more or
less marbled with a lighter shade or white. Ex-
tremity of all spines black." (Rathbun, 1930a.)

Habitat. — Siebenaler (1952) reported C. ruber
as a "trash" form on the Tortugas shrimping
grounds; below low tide mark to 40 fathoms.

Type locality. — Brazil.

Known range. — South Carolina to State of
Santa Catarina, Brazil ; Lower California, Mexi-
co, to Peru and Galapagos Islands; west Africa-
from Senegal to Angola.

Remarks. — Rathbun (1930a) reported ovige-
rous females from May through September in
Curasao, in June from Cuba, and in July from
Jamaica.

Family Cancridae

Carapace broadly oval or hexagonal. Last pair
of legs not adapted for swimming. Antennules
folding lengthwise. Antennae with flagella more
or less hairy.

Genus Cancer Linnaeus, 1758

Rathbun, 1930a, p. 176.— Hemming, 1958b, p. 51.

MacKay (1943) gave a review of the modern
world distribution of members of the genus Can-
cer, as well as the geologic record which dates
from the Eocene Period. The modern distribu-
tion of the genus is limited, apparently by tem-
perature, to the temperate zones except along the
northwestern coast of South America in the cold
Humboldt Current.

174

FISH AND WILDLIFE SERVICE

KEY TO SPECIES IN THE CAROLINAS

a. Anterolateral teeth of carapace with margins granu-
late ; chelipeds granulate, not denticulate

irroratua (p. 175).
aa. Anterolateral teeth of carapace with denticulate mar-
gins ; upper margin of palm denticulate

borealis (p. 175).

Cancer irroratus Say. Rock crab

Figure 155

Cancer irroratua Say (in part), 1817, p. 59, pi. 4, fig. 2.—
Hay and Shore. 1918, p. 435, pi. 35, fig. 1.— Rathbun, 1930a,
p. 180, test-fig. 29, pi. 85, fig. 1 (rev.).

Recognition characters.— Carapace approxi-
mately two-thirds as long as wide, convex, granu-
lated. Anterolateral border divided into nine
teeth with margins granulate, not denticulate as
in C. borealis, and with notches between teeth
continued on carapace as short, closed fissures
giving teeth a pentagonal character. Postero-
lateral border a granulated ridge with one tooth
at outer end similar to those of anterolateral
border but smaller. Front with three teeth, middle
one exceeding others and depressed.

Chelipeds of moderate size, not so long as sec-
ond pair of legs; carpus with granulated ridges
and a sharp spine at inner distal angle; hand
nearly smooth on inner face, outer face with four
or five granulated lines, two lower ones continued
on slightly deflexed immovable ringer, superior
one cristate. Walking legs rather long and slen-
der; merus of first and second pairs extending
far beyond carapace. Abdomen of male broad,
first, second, and third segments with transverse
granulated ridge.

Figure 155.— Cancer irroratus Say. Male in dorsal view,
reduced (after Rathbun, 1884).

Measurements. — Carapace: length, 65 mm.;
width, 95 mm.

Color.— Yellowish closely dotted with dark
purplish brown, becoming reddish brown after
death.

Habitat. — Most individuals taken near Beau-
fort, N.C., are immature, but larger specimens
have been taken farther from the coast. This spe-
cies, and the following one, are members of a
northern fauna with ranges extending south of
the Carolinas only in deep water. Low water mark
to 314 fathoms.

Type locality. — "Inhabits the ocean." [Atlan-
tic coast of United States.]

Known range.— Labrador to South Carolina;
shallow water in the North, deeper water in the
South.

Remarks.— This species has a fossil record ex-
tending from the Miocene to the present in North
America (MacKay, 1943). Ovigerous females are
known to occur in March in Florida, and have
been reported in August from Massachusetts
(Kathbun, 1930a).

Cancer borealis Stimpson. Jonah crab; northern crab

Figure 156

Cancer borealis Stimpson, 1859, p. 50.— Hay and Shore, 1918,
p. 434, pi. 35, fig. 2.— Rathbun, 1930a, p. 182, text-fig. 30 (rev.).

Recognition characters.— Carapace transversely
oblong, approximately two-thirds as long as wide,
angular at sides, surface granulate. Anterolateral
margins divided into nine quadrangular, crenate
lobes or teeth, with margins minutely denticulate
and with notches between teeth continued on cara-
pace as short closed fissures. Front produced
beyond internal orbital teeth and provided with
three teeth, center one longest and depressed.
Orbits circular, with two narrow fissures above
and two below ; suborbital lobe strongly produced.

Chelipeds nearly as long as second pair of legs,
stout; carpus and hand with strong, granulose
rugae; carpus with sharp spine at inner angle;
hand smooth on inner face, heavily rugose on
outer face, two rugae continued from hand on
slightly deflexed immovable finger; dactyl with
rough upper surface, both fingers slaty black at
tip. Walking legs short, fringed beneath, dactyls
dark tipped.

Measurements. — Carapace: length, 62 mm.;
width, 91 mm.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

175

Figure 156. — Cancer borealis Stimpson. Male in dorsal
view, reduced (after Smith, 1879).

Color. — Yellowish beneath, red above; back
with two curved lines of yellowish spots and,
behind middle, a figure somewhat resembling
letter H; legs mottled and reticulated with yellow
and red, more or less purplish.

Habitat. — Small and immature individuals are
found in the Beaufort, N.C., harbor region ; larger
individuals occur in deep water off the coast; be-
tween tides among rocks to 435 fathoms.

Type localities. — Nova Scotia to Cape Cod.

Known range. — Nova Scotia to south of Tor-
tugas, Fla. ; Bermuda.

Remarks. — This species has a fossil record dat-
ing from the Miocene of North America (Mac-

Kay, 1943). Ovigerous females are recorded in
June from southern Florida.

Family Xanthidae

Crabs with body transversely oval or trans-
versely hexagonal. Front broad, never produced
in form of a rostrum. Last pair of legs normal.
Antennules folding obliquely or transversely.
Male openings rarely sternal (Rathbun, 1930a).

In the key to the genera of Xanthidae in the
Carolinas it has been impossible to use char-
acters which show the general relationships unless
pleopods of the males are employed . Differences
between genera are often subtle and the general
worker is, therefore, compelled to use a combina-
tion of trivial characters for identification. Be-
cause most of the genera occurring in the Caro-
linas contain a single species, the generic key is
in large part also a key to species. Parts of the
key have been adapted from Rathbun (1930a)
and Ryan (1956).

Arrangement of the genera differs in some
respects from that of Rathbun and is based on
similarities and differences in the first pair of
male pleopods. In such arrangement I follow
broadly the arrangements of Stephensen (1945)
and Monod (1956). As in Rathbun (1930a) and
Monod (1956), no attempt is made to divide the
family Xanthidae into subfamilies, though at'
least three well-marked groups appear in the
Carolinas, and perhaps the third of these groups
(fig. 183) could be split into additional groups.

KEY TO GENERA IN THE CAROLINAS

a. Entire body and legs with surface deeply and intricately eroded, resembling piece of stony coral .Glyploxanthus (p. 185).
aa. Entire body and legs with surface not deeply and intricately eroded.

b. Antennae widely separated from orbits Eriphia (p. 182).

bb. Antennae not separated from orbits.

c. Chelipeds with a large notch clearly forming an open hole between carpus and hand when viewed fronts lly with

chelipeds fully pressed against body Carpoporus (p. 186).

cc. Chelipeds without a large notch clearly forming an open hole between carpus and hand when viewed frontally
with chelipeds fully pressed against body.

d. Extreme edge of frontal margin with shallow transverse groove, each half appearing double (under magnification),
e. Carapace more or less nodose in front, upper edge of frontal groove formed by line of nodules .Leptodius (p. 192) .

ee. Carapace not nodose in front but with transverse ridges on dorsum Rhithropanopeus (p. 187).

dd. Extreme edge of frontal margin not transversely grooved, each half presenting but a single edge (under magni-
fication).

e. Teeth of anterolateral border subtriangular or with edges flattened and rounded; carapace never nodose,
f. Carapace with regions on dorsum defined; carapace not smooth to unaided eye.

g. Major cheliped with a more or less conspicuous tooth at base of dactyl, tooth larger than adjacent
teeth and often of contrasting color.

176 FISH AND WILDLIFE SERVICE

h. Third and fourth teeth of anterolateral border definitely pointed forward with outer borders curved,
i. Tooth at base of major dactyl large and conspicuous; body definitely arched above. Panopeus (p. 196).
ii. Tooth at base of major dactyl present but often not large and conspicuous; posterior two-thirds

of carapace flattened above Eurypanopeus (p. 194).

hh. Third and fourth teeth of anterolateral border triangular and pointing outward or slightly for-
ward, outer borders not conspicuously curved Hexapanopeus (p. 188).

gg. Major cheliped with no tooth at base of dactyl, or with obsolescent tooth little if any larger than adjacent
teeth.

h. A red spot on internal face of ischium of third maxillipeds Eurypanopeus (p. 194).

hh. No red spot on internal face of ischium of third maxillipeds Neopanope (p. 190).

ff. Carapace with regions on dorsum obsolete; carapace smooth to unaided eye.

g. Fingers white; anterolateral teeth pointed or rounded Eurytium (p. 199).

gg. Fingers black; anterolateral teeth broad, not pointed, with occasional exception of most lateral tooth;

often attains large size Menippe (p. 183).

ee. Teeth of anterolateral border usually distinctly spiny or spiniform; sometimes subtriangular, serrated or
with spiny tips, and with carapace more or less nodose (nodes occasionally small),
f. Carapace nearly devoid of hairs and with nodose areas on front and anterolateral portions usually clearly

evident, though sometimes poorly developed; adult size small Micropanope (p. 192).

ff. Carapace with either long, plumose hairs, numerous short hairs, or both.

g. Carapace and chelipeds variably spiny; not nodose; with long plumose (clubbed) hairs, short hairs, or

both Pilumnus (p. 177).

gg. Carapace with patches of nodules on anterolateral margins extending back from front; with close pile
of short hair only; body massive, thick Lobopilumnus (p. 181).

Genus Pilumnus Leach, 1815

Rathbun, 1930a, p. 481. — Hemming, 1958b. p. 35.

KEY TO SPECIES IN THE CAROLINAS

a. Hair not covering whole carapace or not forming so
thick a coat as to conceal surface beneath.

1>. Two or more superhero tic spines sayi (p. 177).

bb. No superhepatic spines dasypodus (p. 178).

aa. Hair covering whole carapace and forming a thick
coat concealing surface beneath (hair sometimes worn
off),
b. Chelipeds spinose above ; a transverse row of long

hairs across front floridanus (p. 179).

bb. Chelipeds not spinose above ; carapace tuberculate,
but tubercles often sparse and low.
c. Tubercles of carapace not numerous nor promi-
nent, upper margin of orbit not spinose

lactew (p. 180).

cc. Tubercles on anterior half of carapace and upper

surface of chelipeds numerous, upper margin of

orbit with truncate spines (but occasionally these

poorly developed ) pantwsus (p. 181).

Pilumnus sayi Rathbun. Hairy crab

Figures 157 A, B ; 158

Cancer aculeatus Say, 1818, p. 449.

Pilumnus sayi Rathbun : 1897b, p. 15. — Hay and Shore, 1918.
p. 440, pi. 35. fig. 4.— Rathbun, 1930a. p. 484, pi. 200, figs. 1-2;
pi. 201, figs. 4-7 (rev.).

Recognition characters. — Carapace about three-
fourths as long as wide, anterior half semicir-
cular, strongly deflexed, sparsely covered with
long filiform and plumose hairs. Anterolateral
border with four marginal spines including outer

orbital ; two curved spines on hepatic region with
sometimes one, two, or three supplementary
spines; one long spine and sometimes spiniform
tubercles between first and second marginal spines
below margin. Orbit armed with three long spines
above, and four long and two to four short spines
below. Front advanced, deeply notched in center,
less so on each side, armed with about four spines
on each side.

Superior surfaces of chelipeds and walking legs
with many filiform and plumose hairs; carpal and
propodal articles most thickly covered and with
several strong spines as well. Chelipeds large,
unequal ; carpus with 15 or 20 erect dark spines ;
spines of hand strong and acute above but be-
coming smaller on external surface, spines tending
to arrangement in rows on large hand; fingers
ribbed, dark, and with obtuse teeth ; dactyl spiny
above at base.

Measurements. — Carapace: male, length, 23
mm.; width, 32 mm.

Variations. — The specimen taken on Frying
Pan Shoal off North Carolina (Charleston Mu-
seum No. 38.228) reported by Lunz (1939) ap-
pears to be an aberrant specimen of Pilumnus
sayi rather than P. marshi. The specimen lacks
superhepatic spines on the carapace but other-
wise more nearly resembles P. sayi than any other
Western Atlantic species of Pilumnus.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

177

Color. — Grayish brown irregularly suffused
with red or purple on body and legs; spines
black, horn color, or purple; fingers of chelae
black or brownish purple.

Habitat. — This species is fairly common in the
Carolinas, and is often taken on shelly bottom. It
has been taken from wharf piles, buoys (Lunz,
1937a), the sponge Ste?natumenia strobilina
(Lamarck) (Pearse, 1934), and from offshore
reefs (Pearse and Williams, 1951). From low-
water mark to 49 fathoms.

Type locality. — Georgia and east Florida.

Known range. — North Carolina through Gulf
of Mexico and West Indies to Curacao.

Remarks. — Ovigerous females occur in the
Carolinas from May to August, and as early as
March in Florida (Wass, 1955). Chamberlain
(1961) reported four zoeal stages and one mega-
lops stage in the larval development of the species,

Figure 157. — Male first pleopods in medial view ; A, Pilum-
nus sayi Kathbun, entire pleopod ; B, Pilumnus sayi
Hathbun. tip iu detail; C, Pilumnus dasypodus Kings-
li'.v, tip ; I>, Pilumnus floridanus Stimpson, tip; B, Pilum-
nus lacteus Stimpson, tip; F. Pilumnus pannosus Rath-
bun, tip; G, Lobopilumnus ugaxsizii (Stimpson), tip;
0.125 mm. indicated.

Figure 158. — Pilumnus sayi Rathbun. A, male in dorsal
view, walking legs of left side not shown, 10 mm. indi-
cated ; B, large chela in frontal view, 10 mm indicated.

but did not describe the stages in detail. He found
that larval development time varied with tem-
perature (18 days at 30° C, 28 at 21° C.) and
with food. Larvae matured most rapidly when
fed Artemia salina nauplii, did moderately well
on Artemia and algae, but did not transform at
all when fed algae alone.

Pilumnus dasypodus Kingsley

Figures 157C, 159

Pilumnus dasypodus Kingsley, 1879, p. 155. — Rathbun, 1930a,
p. 493, pi. 200, figs. 5-6 (rev.).

Recognition characters. — Carapace thinly cov-
ered on anterior two-thirds with long, fine hair
and occasional stouter setae; upper surface of
chelipeds and walking legs similarly clothed;
small sharp granules on anterolateral region.
Anterolateral border with four spines including
small outer orbital; spines with bases conical,
extremities long, slender, incurved. Orbital
border with three or four spines above and about
seven below. Frontal lobes separated by a

178

FISH AND WILDLIFE SERVICE

median V- or U-shaped notch; margins furnished
with short spines or sharp granules, with an outer
tooth separated from remainder of margin by a
U-shaped notch.

Chelipeds unequal, spinose, and granulate ex-
cept for smooth and naked lower distal two-thirds
of outer surface of major palm, spines and gran-
ules not arranged in rows on upper part of major
palm; fingers of minor chela grooved on outside,
dactyls with rows of sharp granules and hairs at
base. Walking legs spinose above.

Measurements. — Carapace: male, length, 11
mm.; width, 15 mm.

Color. — Body and claws brownish-red color,
legs much lighter; fingers and extremities of
spines brown (Milne Edwards in Rathbun,
1930a).

Habitat. — This species has been taken from
pilings, jetties, and buoys (Lunz, 1937a), and
from offshore reefs (Pearse and Williams, 1951)
in the Carolinas; and from similar situations
elsewhere (Rathbun, 1930a) including loggerhead
sponge Speciospongia vespara (Lamarck)
(Pearse, 1934). One-half to 16 fathoms.

Type locality. — Key West, Fla.

Known range. — Off Cape Hatteras, N.C.,
through Gulf of Mexico and West Indies to State
of Santa Catarina, Brazil.

Remarks. — This species is not so common in the
Carolinas as P. sayi, and small specimens of
dasypodus are not always easily distinguished
from sayi. Rathbun (1930a) stated that, "dasy-
podus is less heavily clothed with hair than sayi
and less ragged looking. The front is more de-
flexed and less advanced, therefore appears wider.
The spines and tubercles of the major palm in
sayi are arranged more or less in rows and these
rows have a tendency to encroach on the lower
distal half; in dasypodus there are seldom any
definite rows and the lower distal two-thirds or
one-half in both sexes is smooth and bare. The
immovable finger of the major chela in dasypodus
is a little longer than in sayi."

Lunz (1937a) reported ovigerous females from
April through August in the Carolinas, and they
have been found in North Carolina in September.
In the West Indies they occur at all seasons of
the year (U.S. National Museum records).

Pilumnus floridanus Stimpson

Figures 157D, 160

Pilumnus floridanus Stimpson, 1871a, p.
p. 507, pi. 205, figs. 3-4 (rev.).

141. — Eathbun, 1930a,

Figure 159. — Pilumnus dasypodus Kingsley. A, male in
dorsal view ; B, large chela in frontal view ; 5 mm. in-
dicated.

Recognition characters. — Carapace covered
with dense, short pubescence thinning behind,
and with a few longer clavate hairs, a conspicuous
transverse series of these crossing frontal region.
Anterolateral margin with four somewhat conical
spines; a small subhepatic spine between outer
orbital and second spine; hepatic region slightly
roughened but with no spines. Frontal lobes al-
most bare, edge slightly oblique, entire, with
median triangular notch and rounded lateral
notches; tooth at outer angle minute, deflexed.
Orbital margin unarmed above, with 8 to 10
spinules below.

Chelipeds spinose above ; merus with two spines
near distal end on upper surface; carpus armed
over entire exposed surface; spines on hand be-
coming pointed tubercles on outer surface. Male
with large hand smooth and bare on outer lower
half or less of surface, smooth portion more
restricted in female. Walking legs spined above.

Measurements. — A small species. Carapace:
male, length, 7 mm.; width, 10 mm.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

179

Figure 160. — PUumnus floridanus Stimpson. A, animal in
dorsal view, walking legs of left side not shown ; B,
large chela in frontal view ; 5 mm. indicated.

Habitat. — In North Carolina this species has
been taken from an offshore reef (Pearse and
Williams, 1951) and has been found in sponges.
Rathbun (1930a) listed it as taken from rocks,
grass, and a variety of bottoms. Low-tide mark
to about 80 fathoms.

Type locality. — Tortugas, [Fla.].

Known range. — Off Cape Lookout, N.C.,
through eastern Gulf of Mexico, and Yucatan
Channel, to Honduras; through West Indies to
Venezuela.

Remarks. — This species is not common north of
Florida. Ovigerous females are known from
March to August in Florida (Rathbun, 1930a, in
part) and they have been taken in February in
North Carolina.

PUumnus lacteus Stimpson. Small hairy crab

Figures 157E, 161

PUumnus lacteus Stimpson, 1871a, p. 142 Hay and Shore,

1918, p. 440, pi. 35, flg. 3.— Rathbun, 1930a, p. 511, pi. 205, flgs.
1-2 (rev.).

Recognition characters. — Carapace about three-
fourths as long as wide, covered with short velvet-
like pubescence easily rubbed off (and often is),
nearly smooth, sparse tubercles almost invisible

through hairy coating; a row of five tubercles
paralleling anterolateral and orbital margins,
others scattered. Anterolateral margins with four
anteriorly directed teeth, first or outer orbital
small. Front depressed, deeply notched in middle,
and with a smaller notch near eye. Orbital mar-
gin occasionally a bit uneven but not tuberculate.

Chelipeds dissimilar in size but otherwise
nearly alike, stout, setose, and plumose-hairy,
somewhat tuberculate above, but naked and
polished below and on ventral half or two-thirds
of both inner and outer surfaces of chelae ; merus
with two similar curved spines on upper margin
distally; carpus with a stout spine on inner angle.

Measurements. — Carapace: male, length, 12
mm.; width, 15 mm.

Color. — Gray or pinkish, with plumose hairs
whitish or cream colored; hands and tips of legs
light red.

Habitat. — This crab may be found by a careful
search of wharf pilings about the Beaufort, N.C.,
harbor area, but is rarely taken in dredge hauls.
It has been taken from buoys both in sounds and
at sea in South Carolina (Lunz, 1937a). Rathbun
(1930a) reported it from a variety of situations
farther south. Near low-tide mark to about 8
fathoms.

Figure 161. — PUumnus lacteus Stimpson. A, animal in
dorsal view ; B, large chela in frontal view ; 5 mm. in-
dicated.

180

FISH AND WILDLIFE SERVICE

Type locality. — Cruz del Padre, Cuba, and Key
West, Fla.

Knoxon range. — Near Beaufort, N.C., to Flor-
ida; Cuba.

Remarks. — Ovigerous females have been re-
ported in December from Florida, and in May
from Cuba (Rathbun, 1930a) and South Carolina
(Lunz, 1937a).

Pilutnnus pannosus Rathbun

Figures 157F, 162

Pilutnnus pannosus Rathbun, lS96b, p. 142. — Rathbun, 1930a,
p. 514, figs. 4-5 (rev.).

Recognition characters. — Carapace about three-
fourths as long as wide, almost entirely covered
with unevenly distributed, soft, thick, velvety
pubescence, with scattered longer club-shaped
setae giving ragged appearance; lobulations of
anterior portion of carapace and tubercles of
chelipeds showing through pubescence. Anterior
half of carapace and upper surface of chelipeds
and legs dotted with beadlike tubercles. Ante-
rolateral margin with four triangular spines
(outer orbital small) having slender forward-
projecting tips; subhepatic spine between first
and second tooth well developed. Frontal lobes
(when well formed) broadly subtriangular,
granulate on margin, separated by a V-shaped
notch; outer tooth of front almost triangular,
acute (blunt at tip in some specimens). Upper
margin of orbit with three truncate teeth covered
by pubescence, lower margin with a row of short,
stout, truncate teeth or tubercles.

Chelipeds with upper surface tuberculate but
usually with large part of outer surface smooth
and naked; small hand with outer surface often
rough with rows of spines; dactyls with a few
tubercles near articulation. Male with shallow
grooves on fingers, female with well-defined
grooves on minor fingers and fixed major finger.
"Walking legs pubescent, fringed with club-shaped
setae mixed with long fine hair.

Measurements. — Carapace : male, length, 9 mm. ;
width, 12 mm.

Color. — Carapace under pubescence and bare
part of palms bright red (Milne Edwards in
Rathbun, 1930a).

Habitat. — Pearse and Williams (1951) listed
this species as taken from a submerged rocky reef,
and Rathbun (1930a) listed it from similar situa-

MARENE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 O— 65 13

Figure 162. — Pilutnnus pannosus Rathbun. Male in dor-
sal view, walking legs of left side not shown, 2 mm.
indicated.

tions, as well as from sponges and corals. A few
feet to 9 fathoms.

Type locality. — Key West, Fla.

Known range. — Bogue Sound off Beaufort,
N.C., to Port Aransas, Tex.; West Indies to
Virgin Islands.

Remarks. — The species has rarely been taken
north of Florida. Rathbun (1930a) listed oviger-
ous females in December and January from
Florida, and they are known from April to
August between South Carolina and Cuba.

Genus Lobopilumnus Milne Edwards, 1880

Rathbun, 1930a, p. 525.

Lobopilumnus agassizii (Stimpson)

Figures 157G, 163

Pilumnus agassisii Stimpson, 1871a, p. 142.

Lobopilumnus agassisii: Hay and Shore, 1918, p. 441, pi. 34,
fig. 5. — Rathbun, 1930a, p. 526, pi. 211 (rey.).

Recognition characters. — Regions of carapace
protuberant, surface pubescent, except naked and
thickly granulated on anterior and anterolateral
regions; depressions between regions broad, oc-
cupying as much area as regions themselves.
Front consisting of two large lobate masses
deeply separated from each other and from orbits.
Orbital region protuberant and granulate, margin
crenulated with granules, with two fissures above
and two very narrow ones below. Anterolateral
margin with three triangular, spine-tipped teeth
of moderate, equal size ; subhepatic tooth distinct.

181

Figure 163. — Lobopilumnus agassizii (Stimpson). A,
male in dorsal view, walking legs of left side not shown ;
B, large chela in frontal view, 10 mm. indicated.

Chelipeds short, stout; carpus with forwardly
directed granules, confluent exteriorly; hands
with superior and outer surfaces covered with
small prominent mammillary tubercles, arranged
largely in rows on outer surfaces and having
apices directed forward. Walking legs pubescent
and hairy, carpal and propodal articles with
minute spines above.

Measurements. — Carapace: female from North
Carolina, length, 16 mm. ; width, 21 mm.

Variations. — Rathbun (1930a) stated that this
species is variable as to the number and promi-
nence of regions on the carapace, and she rec-
ognized four environmental forms within the
species. Because only one specimen has ever been
reported from North Carolina, and this is no
longer extant, it is not possible to assign a form
or forms to this area.

Color. — Gray above with granules and knobs
yellowish red and reddish brown; legs white or
witli whitish spots (Sohmitl in Rathbun, 1930a).

Habitat.— In Bermuda, Verrill (1908) found
the carapace and legs of this species often thickly
covered, sometimes almost concealed, by a coating
of calcareous mud and sand adhering to hairs on

the back. He found it most frequently under
stones and dead corals at low tide. Pearse ( 1934)
reported this crab from loggerhead sponge
Speciospongia vespara (Lamarck). Low-tide
mark to 28 fathoms.

Type locality. — Typical form : East and Middle
Keys, Tortugas, Fla.

Known range. — North Carolina; southern and
west Florida; Yucatan; Cuba; Trinidad; Ber-
muda.

Remarks. — Ovigerous females are known from
February to July in Florida and Cuba ( Rathbun,
1930a, in part).

Genus Eriphia Latreille, 1817

Rathbun, 1930a, p. 545.

Eriphia gonagra (Fabricius)

Figures 164 A, B, C ; 165
Cancer gonagra Fabricius, 1781, p. 505.

Eriphia gonagra: Hay and Shore, 1918, p. 439, pi. 35, fig. 6.-
Rathbun, 1930a, p, 545, text-fig. 83, pi. 222 (rev.).

Recognition characters. — Carapace approxi-
mately quadrate, about one-fourth wider than
long, flattened, with regions clearly marked off
on anterior two-thirds; surface nearly smooth
posteriorly but granulate anteriorly, and with
two transverse lines of subspinous granules, one
in front of epigastric lobes and another across
protogastric and hepatic lobes. Front wide,
strongly deflexed, and divided into four lobes,
both median lobes broader and more advanced
than lateral ones, and with a finely granulate
border. Lateral lobes forming front of raised
margin of orbits and in contact beneath with a
prolongation of infraorbital plate, thus com-
pletely excluding antenna from orbit. Antero-
lateral margins each with a row of five spines
including outer orbital, behind and inside these a
few squamiform tubercles.

Chelipeds unequal, strong, swollen; hands
covered with large, round, flattened, squamiform
tubercles, more elevated on small than on large
hand; carpus with less prominent tubercles;
dactyls with squamiform tubercles above at base;
major dactyl with large rounded tooth at base.
Walking legs rather slender, their distal three
articles with fine stiff hairs.

Measurements. — Carapace: male, length, 31
mm.; width, 44 mm.

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FISH AND WILDLIFE SERVICE

Color. — Gaily colored. Anterior half of cara-
pace and a broad median stripe extending to
posterior margin, dark purplish brown, legs a
lighter tint of same color; front margined with
brownish orange. Sides of carapace, upper sur-
face of chelipeds, dactyls, bases of legs, and a
narrow band on distal margin of other articles,
light yellow. Tubercles on upper half of cheli-
peds, dark blue; on lower half, yellow. Under-
parts of body and chelipeds, white, fingers brown.
Rathbun (1930a) gives another detailed color
description.

Habitat.— The species has been found in a
variety of situations: under flat rocks above the
watermark, in seaweed, sponges, brackish ponds,

Figure 164. — Eriphia gonagra (Fabricius) ; A, entire first
pleopod, 0.75 mm. indicated ; B, tip of first pleopod, 0.25
mm. indicated ; C, tip of second pleopod, 0.75 mm.
indicated; Menippe mercenaria (Say); D, tip of first
pleopod ; E, tip of second pleopod ; 5 mm. indicated.

Figure 165. — Eriphia gonagra (Fabricius). Male in dor-
sal view, walking legs of left side not shown, 10 mm.
indicated.

tide pools, and on coral reefs. Shoreline to shal-
low water of uncertain limits.

Type locality. — Jamaica.

Known range. — North Carolina to Argentine
Patagonia.

Remarks. — Ovigerous females are known from
March to September in various parts of the West
Indies and southern Florida; in October from
Santa Catarina, and February from Bahia, Brazil
(Rathbun, 1930a, in part).

Genus Menippe de Haan, 1833

Rathbun, 1930a, p. 472.

Menippe mercenaria (Say). Stone crab

Figures 164 D, E ; 166
Cancer mercenaria Say, 1818, p. 448.

Menippe mercenaria: Hay and Shore, 1918, p. 439. pi. 35, fig.
8.— Rathbun, 1930a, p. 472, text-fig. 78, pis. 191-193 (rev.).

Recognition characters. — Carapace transversely
oval, approximately two-thirds as long as wide,
convex, nearly smooth to unaided eye, minutely
granulate and punctate. Anterolateral border
divided into four lobes : first two wide, third wide
but dentiform, fourth much narrower and denti-
form. Front with a median notch and a broad
trilobulate lobe on each side. Orbital border
thick, fissures indistinct.

Chelipeds large and heavy, unequal, nearly
smooth; inside surface of hands with a patch of
fine, oblique, parallel striae serving as a stridulat-
ing organ and adapted for playing against thick
edee of second and third anterolateral teeth and

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

183

Figure 166. — Menippe merecnaria (Say). Male in dorsal view, approximately X 0.6 (after Rathbun, 1884).

outer suborbital tootli ; dactyl of major chela with
a large basal tooth, and immovable finger with a
large subbasal tooth; fingers of minor chela with
numerous small teeth. Walking legs stout, hairy
distally.

Mi asurement8. — Female: length of carapace, 79
mm., width, 116 mm.; length of cheliped, 155 mm.
This is the largesl xanthid species in the area.

Color. — Young individuals dark purplish blue,
very young always with a white spot on carpus.
Older individuals become a dark brownish red
more or less mottled and spotted with dusky
gray ; lingers dark.

Habitat. — The young resort to deeper channels
of saltier estuaries where they live under shell

fragments. Young have also been taken from
buoys in South Carolina (Lunz, 1937a). On at-
taining a width of about one-half inch, they ap-
parently move to shallower water and ma}' be
found among oyster shells, on rocks, pilings, and
about jetties. (In northwest Florida, M. mer-
cenaria apparently prefers turtle grass (Th-a7assm
testudinum) flats (Wass, 1955).) Here they live
until they have attained nearly full size when they
may move to some shoal and make burrows just
below low-tide mark. Such burrows are about f>
inches in diameter and extend for \'2 to 20 inches.
The crabs can be taken from burrows by hand
if the collector keeps his hand against the upper
wall of the hole, and a number of specimens for

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FISH AND WILDLIFE SERVICE

the Institute of Fisheries Research Laboratory
have been taken in this manner. Specimens have
also been taken from baited plots set for capture
of blue crabs, and in trawls from the oceanic
littoral. Surface to 28 fathoms.

Type locality.— "The Southern States."

Known range. — Cape Lookout, N.C., to Yuca-
tan, Mexico; Bahamas; Cuba; Jamaica.

Remarks. — The genus Menippe has a fossil
record in North America dating from the Cretace-
ous, the thick, hard exoskeleton no doubt enhanc-
ing its chances of fossilization. The record for
M. mercenaria dates from the Pleistocene (Rath-
bun, 1035).

Ovigerous females have been taken from May
to July (perhaps August) in North Carolina.
Binford (1912) discussed spermatogenesis and
fertilization in the species and gave notes on
spawning habits. Porter (1960) reviewed litera-
ture on fecundity and larval development of M.
mercenaria and described zoeal stages reared in
the laboratory. Females have been observed to
molt, then mate immediately after spawning in
the laboratory, and produce a new sponge a week
after the previous egg mass has hatched. Sub-
sequent to such mating, more than one mass of
eggs may be produced before another molt or mat-
ing occurs. Females have been known to produce
six egg masses in 69 days, each mass containing
between 500,000 and 1 million viable eggs.

Porter described one prezoeal and six zoeal
stages for larvae reared in culture on Artemia
nauplii, but the prezoeal and sixth stages were
considered as probably atypical. Length of larval
life was approximately 27 days under the condi-
tions imposed, and from experimental data it was
concluded that warm water of high salinity is
needed for optimum survival.

Manning (1961) gave data on relative growth,
showing that the juveniles have a relatively
broader front than adults. Both he and Wass
(1955) pointed out the superficial resemblance
of young M. mercenaria to Panopeus herbstii and
Eurytium limosum. and Manning gave distin-
guishing characters for each species at compara-
ble sizes. Further, the stridulating mechanism
was shown not to be visible in small specimens
and, indeed, stridulation itself has not been ob-

served in the adults (Guinot-Dumortier and
Dumortier, 1960).

In studies on the relationship of number and
volume of gills to oxygen consumption, Pearse
(1929) and Ayers (lOi'.S) found this form, along
with other mud crabs, intermediate between the
sluggish common spider crab and the more active,
partially terrestrial, fiddler and ghost crabs.
Pearse also found that M. mercenaria could with-
stand considerable dilution of the environment
with fresh water. Gray (1957) found gill area
per gram of weight to be intermediate in an array
of species ranging from land to shallow-water
habitats.

Menzel and Hopkins (1956) found the stone
crab in Louisiana to be an active predator on
oysters. The powerful crabs killed small and
large oysters alike. Though predation was
found to be lowest in winter and highest in fall,
the average rate of consumption in the area
studied was 219 oysters per crab per year
( = 1,000 bushels of oysters per acre if this num-
ber were available) .

Genus Glyptoxanthus Milne Edwards, 1879

Rathbun. 1930a. p. 263.

Glyptoxanthus erosus (Stimpson)

Figures 167. 183A

Actaea erosa Stimpson. 1859. p. 51.

Glyptoxanthus erosus: Rathbun. 1930a, p. 263. pi. 107 (rev.).

Figure 167.— Glyptoxanthus erosus (Stimpson). Animal
in dorsal view, detail shown on right side, 5 mm. indi-
cated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

185

Recognition characters. — Surface of body and
legs covered with rough vermiculations, with
furrows or cavities between them narrow, making
a regular pattern and giving body an eroded ap-
pearance; elevated portions between furrows or
cavities formed by masses of small granules
crowded together producing rough surface in
young and half-grown individuals, but variably
worn smooth in old ones; margins of cavities
with short pubescence. Carapace areolated, but
divisions obscured to large extent by character of
surface; lateral boundaries of gastric region and
median suture from front to middle of gastric
region deep. Front steeply inclined, median lobes
evenly rounded, margins granulate. Ischium of
third maxilliped with deep, longitudinal, central
groove.

Chelae short and broad, upper surface divided
by furrows into transverse tuberculate ridges,
outer surface divided into longitudinal tuber-
culate ridges; fingers short, deeply grooved, even
toothed; dactyls tuberculate at base on upper
side. Walking legs with hairy edges, dactyls
pubescent.

Measurements. — Carapace: male, length, 39
mm. ; width, 54 mm.

Color. — Eathbun (1930a) described a specimen
in formalin as cream white with blotches and
small spots of bright red, color especially per-
sistent on walking legs, with dactyls red at base
and yellowish distally.

Habitat. — The species has been taken from
rocks and the alga Halimeda in shallow water,
from coarse sand, and from sponges and coral
reefs in deeper water. Low-tide mark to 37
fathoms.

Type locality. — Florida.

Known range. — Cape Lookout, N.C., to
Yucatan; through West Indies to Guadeloupe.

Remarks. — Ovigerous females have been taken
off northeast Florida in January.

Genus Carpoporus Stimpson, 1871

Rathbun, 1930a, p. 269.— Hemming, 1958b, p. 14.

Carpoporus papulosus Stimpson

Figure 168, 183B

Carpoporus papulosus Stimpson. 1871a, p. 139.— Rathbun.
1930a, p. 269, pi. 110, figs. 3-6, pi. Ill (rev.).

h'( cognition characters. — Carapace subhexago-
nal, ncn rly as long as broad, naked above ; regions

Figure 168. — Carpoporus papulosus Stimpson. A, animal
in dorsal view, legs of left side not shown ; B, oheliped
in frontal view partially extended ; 3 mm. indicated.

protuberant, somewhat wartlike and granulated,
gastric and epibranchial regions prominent. Two
or three small, spiniform lateral teeth, interspaces
armed with denticles. Front strongly projecting
at middle, bilobed, margin concave, inner end
rectangular, outer end spiniform. Peduncle of
eye granulated; orbit with margin granulate
above. Exposed surface of third maxilliped with
beadlike granules.

Chelipeds when retracted having a large hole
between carpus and hand for passage of water
to afferent branchial apertures; inner surface of
hand witli two unequal peglike spines near middle
forming a kind of filter in front of branchial
opening; carpus and hand sculptured externally
with granulated protuberances, arranged in four
or five serial rows on hand; hand serrate above
with four teeth partially joined; fingers stout,
short. Walking legs hairy below.

Measurements. — Carapace: male, length, 13
mm.; width, 16 mm.

Habitat. — Eighteen to 62 fathoms.

Type localities. — Southwest of Tortugas, and
off Carysfort Reef, [Fla.].

Knovm range. — Between Capes Hatteras and
Lookout, N.C. ; Cape Catoche, Yucatan, Mexico.

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FISH AND WILDLIFE SERVICE

Genus Rhithropanopeus Rathbun, 1S98

Rathbun, 1930a, p. 455.— Hemming, 1958b, p. 37.

Rhithropanopeus harrisii (Gould)

Figures 169, 183C

Piliimnus harrisii Gould, 1841, p. 320.

Rhithropanopeus harrisii: Hay and Shore, 1918, p. 441, pi.
35, fig. 5.— Rathbun, 1930a, p. 456. pi. 183, figs. 7-8 (rev.).

Recognition characters. — Carapace subquad-
rate, approximately three-fourths as long as wide,
much less convex from side to side than from
front to back, sparsely pubescent toward antero-
lateral angles; protogastric regions with two
transverse lines of granules; a similar line from
one posterior lateral tooth to opposite one across
nasogastric region. Front almost straight,
slightly notched, and with margin transversely
grooved, appearing double when viewed from in
front. Postorbital angle and first anterolateral
tooth completely coalesced; first and second de-
veloped anterolateral teeth of about same size and
perhaps larger than last one.

Chelipeds unequal and dissimilar; carpus not
grooved above and with a moderately developed
internal tooth; chelae indistinctly costate above.
Major chela with short immovable finger and
strongly curved dactyl. Minor chela with pro-
portionately longer immovable finger and long
straight dactyl. Walking legs long, slender, com-
pressed, and somewhat hairy.

Measurements. — Carapace: male, length, 15
mm. ; width, 19 mm.

Variations. — The chelipeds are nearly smooth
in old individuals, but in small specimens the
carpus is rough with lines and bunches of gran-
ules, the distal groove deep, the upper margin of
palm with two granulate ridges, and the upper
edge of the fingers granulate.

Color. — Brownish above, paler below; fingers
light.

Habitat.— In Chesapeake Bay, Ryan (1956)
found this species distributed primarily in the up-
per bay and in tributaries of the lower bay in
depths of 0 to 5 fathoms. A similar distribution
has been found for upper Delaware Bay (Mc-
Dermott and Flower, 1953) and the tributaries
of the Neuse River estuary in North Carolina.
Ryan collected specimens in waters ranging from
fresh to 18.6 °/0o . The places from which the
form was taken always afforded some kind
of shelter — oyster bars, living and decaying

Figure 169. — Rhithropanopeus harrisii (Gould). Frontal
aspect of body viewed from above, 3 mm. indicated.

vegetation, old cans, and other debris. Bousfield
(1955) found larvae of the species in water from
4 to no higher than 28.5 %0 salinity. Surface
to 20 fathoms.

Type locality. — Cambridge Marshes and
Charles River, Mass.

Known range. — The original range of this spe-
cies was in fresh to estuarine waters from New
Brunswick, Canada, to Veracruz, Mexico; north-
east Brazil. The species has been introduced on
the west coast of the United States and in parts of
Europe.

Remarks. — Connolly (1925) stated that four
zoeal stages and one megalops stage comprise the
larval and postlarval development of this species.
These conclusions were based on study of plank-
ton taken from the Miramichi River estuary, New
Brunswick, Canada, in August. Chamberlain
(1962) confirmed and supplemented Connolly's
account with eggs taken from Chesapeake Bay
and cultured in the laboratory. Duration of larval
stages was twice as long when zoeae were fed cope-
pod nauplii and algae as when fed nauplii alone.
In an array of salinities and temperatures, devel-
opment was found to proceed best at 6 to 10 %0
salinity. Developmental time increased with de-
creasing temperature, Developmental times of
larvae in nature were found to be in agreement
with results of laboratory culturing at similar
salinities and temperatures. Mortality rates for
larvae in nature were found to be lower than ex-
pected. A relatively high rate was postulated for
the megalops or early crab stages. Presence of
adult crabs in fresh water was deemed a result of
migration after larval stages are complete. Hood

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

187

(1962) also described a series of larval and post-
larval stages from eggs hatched and reared under
laboratory conditions in Mississippi.

Ryan (1956) summarized life history data for
R. harrisii in the Chesapeake Bay area. Ovigerous
females were collected from June to September
(also in April in Louisiana and Brazil). Though
juveniles were found in all months of the year,
they occurred most frequently in samples taken
from July to October. Immature forms of unde-
termined sex ranged from 2.2 to 2.6 mm. in width.
Immature males ranged from 3.2 to 5.0 mm. and
similar females from 3.3 to 5.7 mm. in width.
Ryan considered maturity to be reached the fol-
lowing summer at a carapace width of 4.5 mm.
for males and 4.4 to 5.5 mm. in females.

Adults continue to grow and molt after ma-
turity is reached, and males finally attain a larger
size than females (up to 14.6 and 12.6 mm. wide
respectively). No concrete data on number of in-
stars throughout life are available but it is esti-
mated that there may be four instars between at-
tainment of the 5 and 10 mm. carapace widths.

This species has been transported from its
original range to two widely separated areas of
the earth. One of these is the west coast of the
United States where it was reported in the San
Francisco Bay area by Jones (1940) and Filice
(1958), and at Coos Bay, Oreg., by Ricketts and
Calvin (1952). An older and wider introduction
in Europe was reviewed by Buitendijk and Hol-
thuis (1949) who considered the European form a
separate subspecies (R. h. tridentatus (Mait-
land)). Originally confined to the old Dutch
Zuider Zee, the species gradually diminished in
abundance there with the closing of that inland
sea in 1936. In that same year it was first reported
outside Netherlands waters. In 1939 it was first
reported in large numbers from southern Russia
in the Dnjetr and Bug River estuaries, and ac-
cording to fisherman there was first observed in
1936 but certainly not present before 1932. The
latest extension of range was reported by Wolff
(1!>54) in South Harbor of Copenhagen, Den-
mark.

Because this form is easily collected and can
tolerate a low but broad range of salinities, it has
been the subjeci of study in investigations on the
mechanism of osmoregulation (Jones, L941; Ver-
wey,1957).

Genus Hexapanopeus Rathbun, 1898

Rathbun, 1930a, p. 383.

KEY TO SPECIES IN THE CAROLINAS

a. Carpus slightly tuberculate angustifrons (p. 188).

aa. Carpus tuberculate paulensis (p. 189).

Hexapanopeus angustifrons (Benedict and Rathbun).
Narrow mud crab

Figures 170, 183D

Panopeus angustifrons Benedict and Rathbun, 1891, p. 373, pi.
22, fig. 3 ; pi. 24, fig. 18.

Hexapanopeus angustifrons: Hay and Shore, 1918, p. 43,fi, pi.
34, fig. 7.— Rathbun, 1930a, p. 384, pi. 169, figs. 1-2 (rev.).

Recognition characters. — Carapace hexagonal,
about two-thirds to three-fourths as long as wide,
convex from front to back, regions fairly well
marked, surface finely granulate. Anterolateral
edge thin, upturned, and divided into five teeth,
first two separated by a well-defined sinus, third
and fourth successively broader, fifth shorter, nar-
rower, more distinctly directed outward; each of
last two teeth with a ridge extending obliquely in-
ward and backward for distance twice length of
teeth. Front narrow, produced, divided in half
by a prominent V-shaped notch; each half bilo-
bate, with markedly sinuate anterior border form-
ing a broad inner and small, inconspicuous outer
lobe.

Figure 170. Bewapanopeus angustifrons (Benedict and
Rathbun). A. animal in dorsal view; B, large chela
in frontal view; 5 mm. indicated.

INS

FISH AND WILDLIFE SERVICE

Chelipeds strong, granulate, and finely rugose;
merus with a well-developed tooth on upper mar-
gin ; carpus with a moderately deep groove paral-
lel to distal margin, an obtuse tooth at inner angle,
and with superior surface rough and more or less
tuberculate. Hands unequal and dissimilar; palm
usually with a fairly strong ridge above and indi-
cations of one on outer surface, both ridges con-
tinued on fingers; fingers strong, slightly hooked
at tips; dactyl of larger hand with strong tooth at
base.

Measurements. — Carapace: length, '20 mm.;
width, 28 mm.

Color. — Usually dark reddish brown or dark
gray, sometimes a uniform brownish yellow or
light buff; females usually darker than males and
often more or less spotted; fingers black or dark
brown at base, lighter at tips, color not continued
on palm. Often a light yellow band along anterior
border of carapace (Wass, 1955, in part).

Habitat. — Ryan (1956) found this species in-
frequently in the lower portion of Chespeake Bay
in from 6- to 25-fathom water (Cowles, 1930, in
part) and in salinities ranging from 18 to 32°/00.
McDermott and Flower (1953) found the species
only in the lower portion of Delaware Bay.
Rathbun (1930a) recorded the species from oyster
bars along the New England coast, and it is found
in shelly situations in the Carolinas (Lunz,
1937a). Though it occurs in places such as Beau-
fort Harbor, N.C., the species is apparently not
found primarily in shallow water near shore (see
also Wass, 1955). Near shore to 76 fathoms.

Type locality. — Long Island Sound.

Known range. — Vineyard Sound, Mass., to Port
Aransas, Tex. ; Bahamas ; Jamaica.

Remarks. — Ovigerous females are known from
February to August in Florida, in July from
North Carolina and Virginia, and in October
from Texas. Ryan (1956) gave the range in cara-
pace width of mature males as 9.7 to 28.9 mm. and
of mature females as 8.4 to 20.2 mm. in Chesa-
peake Bay. Rathbun (1930a) considered speci-
mens from Chesapeake Bay southward to average
smaller than those from farther north.

Chamberlain (1961) reported four zoeal stages
and one megalops stage in larval development of
the species but did not describe the stages in de-
tail. He found that larval development time
varied with temperature (17 days at 30° O, 28 at

21° C.) and with food. Larvae matured most
rapidly when fed Artemia salina nauplii, matured
moderately well on Artemia and algae, but did
not transform at all when fed algae alone.

Hexapanopeus paulensis Rathbun

Figures 171, 183E
Hexapanopeus paulensis Rathbun, 1930a, p. 395, pi. 170, figs.
5-6.

Recognition characters. — Carapace hexagonal,
approximately two-thirds to three-fourths as long
as wide, convex, regions fairly well marked, sur-
face with approximately 12 transverse granu-
lated lines on gastric, cardiac, and branchial re-
gions. First tooth of anterolateral border small;
second larger, broad, and shallow, with arcuate
outer margin ; third with nearly straight margin
directed forward and inward; fourth and fifth
acute and prominent; sometimes with small
denticle between first, second, or third pairs of
teeth. Front with edge thin, arcuate, with small,
median, V-shaped notch, and each half with small
lobule at outer end. Inner suborbital angle large;
a raised line of granules on subhepatic region.

Chelipeds with carpus and upper part- of palm
roughened; carpus with approximately 15 tu-
bercles above, an internal tooth, and below it a
small tooth or denticle, distal groove deep. Hand
with a superior groove and another on outer sur-
face below upper edge, ridges bordering groove
with low tubercles; fingers deeply grooved, dark
or horn colored, color continued somewhat on
palm, ending in an oblique line; tips light.

Figure 171. — Hexapanopeus paulensis Rathbun. A, ani-
mal in dorsal view ; B, large chela in frontal view ; 5
mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

189

Measurements. — Carapace: male, length, 7
mm., width, 10 mm. ; female, length, 10 mm.,
width, 14 mm.

Habitat. — Three fathoms (Lunz, 1937a).

Type locality. — Santos, Sao Paulo, Brazil.

Known range. — South Carolina, through Gulf
of Mexico to State of Sao Paulo, Brazil.

Remarks. — This species has been reported from
only a few widely separated areas. Rathbun
(1930a) reported ovigerous females in September
from Brazil.

Genus Neopanope Milne Edwards, 1880

Rathbun, 1930a, p. 366.

KEY TO SUBSPECIES IN THE CAROLINAS

a. Fingers white or light horn colored

texana texana (p. 190).
aa. Fingers dark colored texana sayi (p. I'M)).

Neopanope texana texana (Stimpson)

Figures 172, 183F

Panopeua texanus Stimpson, 1859, p. 55.

Neopanope texana texana: Rathbun, 1930a, p. 3167, text -fig. 57,
pi. 168, figs. 1-2 (rev.).

Recognition characters. — Carapace quite con-
vex in both directions, high in middle, length con-
tained in width about 1.3 times, greatest width at
fifth pair of anterolateral teeth. Carapace mi-
nutely pubescent, especially in female; regions de-
fined. First two anterolateral teeth coalesced,
separated by a shallow sinus; first tooth triangu-
lar, second arcuate ; third and fourth teeth sharp,
with tips pointing forward; fifth tooth short,
sharp, directed outward and upward; each of last
two -teeth with a short ridge extending inward.
Front slightly produced, rounded, with small
median notch.

Chelipeds smooth, unequal, and dissimilar;
carpus with subdistal groove, fingers white or
horn colored in males, somewhat darker in fe-
males, color extending somewhat on palm and
terminating in a distinct line; no large tooth at
base of major dactyl. Walking legs long and
slender.

Measurements. — Carapace: male, length, 21
mm.; width, 27 mm.

Variation's. — In individuals 14 nun. wide and
smaller, the carpus is much rougher than I hat de-
scribed al)ove, has a sharper internal spine, ami a
longitudinal groove on the upper surface of t lie
palm. In individuals with a carapace width less

Figure 172. — Neopanope texana texana (Stimpson).
Male in dorsal view, legs of left side not shown, 5 mm.
indicated.

than 5 mm., the first and second anterolateral
teeth are completely coalesced. Where the ranges
of N. t. texana and N. t. sayi overlap, specimens
are often found which share characters of both
subspecies (Rathbun, 1930a, p. 370, in part).

Color. — Body mottled gray; a roughly W-
shaped grayish configuration on anterior half of
carapace with its anterior points located in mid-
line and behind orbits, and a less definite continua-
tion of this figure extending toward anterolateral
borders; hands of chelipeds mottled gray, fingers
with light tips; walking legs with narrow gray
cross bands alternating with lighter ground color.

Habitat. — Most abundant in shallow water
where bottom is soft and there is vegetation
(Wass, 1955). Low tide to 28 fathoms.

Type locality. — St. Josephs Island, Tex.

Known range. — York River, Va., via Florida
Keys and Gulf coast to Laguna Madre, Tamauli-
pas, Mexico.

Remarks. — Ovigerous females have been re-
ported in March from Florida (Rathbun, 1930a),
and they are known from North Carolina in July
and August.

Neopanope texana sayi (Smith*

Figures 173, 183G

I'anopcUH sayi Smith. 1869a, p. 2S4.

Neopanope texana tayi: Hay and Shore, 1918, p. 43S, p!. .'i4,
fig. 8.— Rathbun, 1930a, p. 369, text-fig. 58, pi. 168, figs. 3-4
l rev. J .

tfeopunope texana niyrodigita Rathbun, 1934, pp. 3-4, lllus,

190

FISH AND WILDLIFE SERVICE

Recognition characters. — Carapace subhexag-
onal, length contained in width about 1.3 to 1.4
times, greatest width at fifth pair of anterolateral
teeth, quite convex ; carapace minutely granulate,
and lightly pubescent especially near anterior and
lateral regions. Five anterolateral teeth, first two
coalesced and separated by a shallow sinus, third
and fourth larger and directed forward, fifth
smaller and directed somewhat outward; each of
last two teeth with an oblique ridge extending
inward and backward. Front with small median
notch, each half only slightly sinuate, with whole
forming a much flattened curve extending from
eye to eye.

Chelae barely unequal, smooth, dissimilar; car-
pus and merus with a shallow groove parallel to
distal margin, and usually a blunt internal spine;
major dactyl without large basal tooth, fingers of
minor chelae not spoon shaped.

Resembles Eurypanopeus depressus.
Measurements. — Carapace: length, 17 mm.;
width, 23 mm.

Variations. — Where the ranges of N. t. texana
and N. t. sayi overlap, specimens are often found
which share characters of both subspecies (Rath-
bun, 1930a, p. 370, in part) .

Color. — Carapace a dark, slaty bluish green,
brown or buff, with dark reddish-brown speckles
on yellowish background, or bluish purple on gray
background, especially on anterior portion of
carapace and upper portion of chelae ; outer face
of chelae yellowish gray; fingers dark or black,
color extending extensively on palm, tips light.
Habitat.— -Most studies indicate greatest
abundance on mud bottoms, though the form oc-
curs in other situations as well, and in the Chesa-
peake area in a salinity range of 14.66 to 31.62
°/00 in a dry year. Low-tide mark to 15 fathoms.
Type localities. — New Haven, Conn., and Cape
Cod, Mass.

Knoion range. — Miramichi Bay, Prince Ed-
ward Island and Cape Breton Island, New Bruns-
wick, Canada (Bousfield, 1956), to eastern
Florida. Introduced, Swansea, Wales (Nay lor,
1960).

Remarks. — Rathbun's subspecies N. t. nigro-
digita is here regarded as conspecific with N. t.
texana on the basis of examination of a series of
specimens in the Charleston Museum. Rathbun
(1930a) reported the largest male on record as
27.2 mm. wide.

Figube 173. — Xcopanope texana sayi (Smith). A, male
in dorsal view, walking legs not shown ; B, large chela
in frontal view ; 10 mm. indicated.

Ovigerous females have been taken from April
in South Carolina (Lunz, 1937a) to October in
Chesapeake Bay. Cowles (1930) found young in-
dividuals during fall, winter, and spring in
Chesapeake Bay, and concluded that juveniles
reach maturity the first summer after hatching.
Ryan (1956) summarized the work of Hyman
(1925) on zoeal and megalops stages, and gave
some data on size at maturity. He concluded that
mature females ranged in width from 6.1 to 18.7
mm.

Chamberlain (1957, 1961) discussed develop-
ment time and stages in detail. He found develop-
ment limited to four zoeal stages (sometimes pre-
ceded by a brief prezoeal stage) and one megalops
stage. Developmental time varied with tempera-
ture (14 days at 30° C, 27 at '21° C.) and with
food. Larvae matured most rapidly when fed
Artemia salina nauplii, did moderately well on
Artemia and algae, but did not transform at all
when fed pure algae.

McDermott and Flower (1953) considered this
form to be the most abundant mud crab in Dela-
ware Bay, but within the area studied it was more
common on oyster beds than in littoral or low-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

191

salinity areas. They found (also McDermott,
1960) that N. t. sayi readily preys on B alarms im-
provisus. Farther north, Landers (1954) reported
the crab abundant in Narragansett Bay where it
is a serious predator on young Mercenaria mer-
cenaria. Eyan (1956) found the form widely dis-
tributed in Chesapeake Bay, but apparently not
so abundant as in the more northern bays. Here it
ranged in depth from 2 to 25 fathoms (Rathbun,
1930a, in part), depths similar to those reported
by Sumner, Osburn, and Cole (1913a, b) for the
Woods Hole region.

Genus Leptodius Milne Edwards, 1863

Rathbun, 1930a. p. 296.— Hemming, 1958b. p. 33.

Leptodius agassizii Milne Edwards

Figures 174, 183H

Leptodius agassizii Milne Edwards, 1880, p. 270, pi. 49, fig. 3. —
Hay and Shore, 1918, p. 441, pi. 34, fig. 6. — Rathbun, 1930a, p.
307, pi. 141, figs. 4-5 (rev.).

Recognition characters. — Carapace broad, sub-
oval, flattened, and finely granulate posteriorly,
conspicuously sculptured anteriorly ; regions lobu-
late, with coarse granules and fine scattered hairs
along front margin of lobules. Frontal margin
transversely grooved, appearing double; upper
margin less pronounced than lower, with groove
extending across from orbit to orbit, both edges of
groove and orbital margin granulate. Of five
anterolateral teeth only last two or three well de-
veloped, sharp, and turned forward; second tooth,
and sometimes third, triangular and obtuse, first
(outer orbital angle) represented by an elevated
mass of granules.

Chelipeds unequal; larger one with strong,
blunt-tipped fingers; smaller one with more
slender, more acute, and more conspicuously
grooved fingers showing tendency to be spoon
shaped at tips; fingers dark, both hands with
upper and outer surfaces granulate and tubercu-
late and with tubercles arranged in rows; carpus
strong, with a sharp internal spine, sometimes a
double spine, and with many irregular, granulate
rugae above. Walking legs granulate and hairy.

Measurements. — Carapace: male, length, 8
mm., width, 12 mm.; ovigerous female, length, 20
mm., width, 31 mm.

Variations. — Small specimens from new Beau-
fort, X.C., have the last three anterolateral teeth
well developed, but a series in the U.S. National

Figure 174. — Leptodius agassizii Milne Edwards. A.
carapace in dorsal view; B. carapace in frontal view;
2 mm. indicated.

Museum from Pensacola, Fla., shows that the
number of these spines may be reduced to two in
larger individuals.

Color. — After a short preservation in alcohol,
light red, fingers black.

Habitat. — This species has been taken from
coral rock, sponges, and on sandy bottom. Ap-
proximately 6 to 45 fathoms.

Type locality. — Florida Reefs, 12 to 18 fath-
oms.

Known range. — Cape Hatteras, N.C., to Pensa-
cola, Fla. ; Virgin Islands.

Remarks. — Ovigerous females are known from
April to November in various parts of the range.

Genus Micropanope Stimpson, 1871

Rathbun, 1930a. p. 426. — Hemming. 195Sb, p. 34.

KEY TO SPECIES IN THE CAROLINAS

a. Last lateral tooth of carapace obsolescent, carapace
rough, legs spinulose seulptipes (p. 193).

aa. Last lateral tooth of carapace small but easily dis-
cernible.

b. Second lateral tooth present, last lateral tooth denti-
form, not spinose: outer surface of hand somewhat
rugose xanthiformis (p. 193).

192

FISH AND WILDLIFE SERVICE

bb. Second lateral tooth absent or fused with first;
outer surface of hand rough with large beadlike
granules nuttitigi (p. 104).

Micropanope sculptipes Stimpson

Figure 175

Micropanope sculptipes Stimpson, 1871a, p. 140. — Rathbun,
1930a, p. 428, pi. 178, figs. 1-3 (rev.).

Recognition characters. — Carapace naked, dis-
tinctly areolated; anterior and anterolateral re-
gions somewhat roughened in front with small,
sharp, toothlike tubercles partially disposed in
lines. Anterolateral teeth sharp, denticulate, fifth
(last) obsolescent, first and second almost entirely
fused. Frontal lobes abruptly deflexed, with con-
vex outline; margin thin, minutely crenulate, with
slight furrow above it. A small tubercle on sub-
hepatic region below second anterolateral tooth.

Chelipeds granulate above; carpus with gran-
ules arranged more or less in raised reticulated
rugae, inner margin denticulate and with a sharp
spine; hand with double denticulate crest above
and with minute granules on outer surface show-
ing tendency to arrangement in rows, becoming
obsolete in distal lower half of major chela, upper
part of inner surface granulate ; fingers grooved,
with a thin superior crest on dactyls. Walking
legs with minute spines above forming two rows
on carpus.

Measurements. — Carapace: male, length, 4
mm. ; width, 6 mm.

Habitat. — Fifteen to 101 fathoms.

Type locality. — Florida Keys.
Known range. — South Carolina to Port
Aransas, Tex. ; West Indies to Barbados.

Micropanope xant hi fortnis (Milne Edwards)
Figures 176, 1831
Panopeus xanthijormis Milne Edwards, 1880, p. 353, pi. 53, figs.
4-4b.— Rathbun, 1930a, p. 442, pi. ISO, figs. 7-8 (rev.).

Figure 175. — Micropanope sculptipes Stimpson. Animal
in dorsal view, legs of left side not shown, 2 mm.
indicated.

Figure 176. — Micropanope xanthiformis (Milne Edwards).
Animal in dorsal view, walking legs of left side not
shown, 5 mm. indicated.

Recognition characters. — Carapace depressed,
regions well defined, with depressed coarse granu-
lations on anterior and anterolateral portions, an
oblique ridge on hepatic region. Five antero-
lateral teeth with granulate margins ; second tooth
small, blunt, obsolescent in young but consider-
ably larger than first in adults; third and fourth
teeth large, acute; fifth tooth small and pointed.
Front slightly deflexed, shallow, lobes separated
by a narrow fissure ; margin sinuous, outer corner
rectangular. A slight subhepatic elevation formed
by a number of granules.

Chelipeds rugose with coarser granules than on
carapace ; merus with a row of spines above ; car-
pus with a deep distal groove and two inner
spines, one above other, upper one largest. Chelae
roughened proximally and on upper portion,
roughness more extensive on minor chela; fingers
deeply grooved, major dactyl with large basal
tooth. Walking legs long, slender; merus with
row of spines above, other articles spinulose.

Measurements. — Carapace: male, length, 7
mm. ; width, 10 mm.

Color. — "Anterior portion of carapace light
yellowish orange. Fingers of major chela brown-
ish black, of minor chela black. Spines and tu-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

193

bercles of both chelipeds light salmon." (Rath-
bun, 1930a.)

Habitat. — Various types of bottom in deeper
water; 7.5 to 182 fathoms.

Type locality. — Off Grenada.

Known range. — Cape Hatteras, N.C; Florida
through Gulf of Mexico and West Indies to Cabo
Fi'io, Rio de Janeiro, Brazil ; Yucatan.

Remarks. — Ovigerous females are known in
June and August from Florida, and in October
from North Carolina (Rathbun, 1930a, in part).

Micropanope nuttingi (Rathbun)

Figures 177, 183J

Xanthiaa nuttingi Rathbun, 1898, p, 271, pi. 4, flg. 1.
Micropanope nuttingi: Rathbun, 1930a, p. 450, flg. 74 (rev.).

Recognition characters. — Carapace suboval,
convex from front to back, nearly flat trans-
versely ; regions distinct, anterior half rough with
squamose tubercles. Second normal anterolateral
tooth completely united with small first tooth;
three remaining teeth sharp pointed, posterior one
smallest. Front convex, bilobulate, with granulate
margins separated by a V-shaped sinus, outer
angle of each lobe subrect angular.

Chelipeds heavy, quite unequal ; merus spinu-
lose on upper edge ; carpus covered with beadlike
tubercles, with a deep distal groove, and an inner
angular eminence tipped with a spinule and a
second spinule below. Females with whole outer
surface of both chelae tuberculate. Major chela
of males with upper and approximately two-
thirds of outer surface beaded, tuberculate; lower
third and distal extremity smooth and shining;
fingers broad, not gaping, brown with light tips,
color of immovable finger not continued on palm
and ending in a line with articulation of dactyl;
dactyl with large basal tooth. Minor chela almost
entirely tuberculate, growing less so toward distal
and lower margins; upper margin with longi-
tudinal groove, lingers deeply grooved. Upper
margin of walking legs tuberculate or granulate.

Measurements. — Carapace: male, length, 4
mm.; width, 6 mm.

Color. — "In alcohol, speckled with blue; larger
patches of blue on anterior gastric and cardiac
region." (Rathbun, 1930a.)

Habitat. — Has been taken from boulder-covered
beach, from Pontes clumps and Halimede (U.S.
National Museum records); shallow water to
100 fathoms.

Figure 177. — Micropanope nuttingi (Rathbun). Animal
in dorsal view, walking legs of left side not shown. 2 nun.
indicated.

Type locality. — Bahama Banks.

Known range. — Cape Hatteras, N.C, through
Gulf of Mexico and West Indies to Cape Sao
Roque, Rio Grande do Norte, Brazil.

Remarks. — Ovigerous females have been taken
in July in Florida.

Genus Eurypanopeus Milne Edwards, 1880

Rathbun, 1930a, p. 403.

KEY TO SPECIES IN THE CAROLINAS

a. Fingers of both chelae with acute tips, not spooned

iilibririatii.i ( p. 194).
aa. Fingers of minor chela spoon-shaped at tip

depressus i p. 195 i .

Eurypanopeus abbreviatus (Stimpson)
Figures 178, 1831K

Panopeus abbreviatus Stimpson, 1860a, p. 211.
Eurypanopeus abbreviatus: Rathbun, 1930a, p. 404. text-fig.
63, pi. 172, figs. 1-2 (rev.).

Recognition characters. — Carapace approxi-
mately two-thirds broader than long, moderately
convex in two directions, naked above, granulate
and uneven on front and along anterolateral bor-
der, smooth and polished elsewhere; areolations
slightly hut distinctly indicated, a number of
well-marked rugae among granules. Front
strongly detlexed, four-lobed, median lobes promi-
nent, separated by a V-shaped notch. Antero-

194

FISH AND WILDLIFE SERVICE

Figure 178. — Ettrypanopeus abbrcviatus (Stimpson). A,
male in dorsal view, walking legs not shown ; B, right
chela in frontal view ; front with anomalous notch to
right of midline; 5 mm. indicated.

lateral margin thin, divided into four lobes, first
and second teeth coalesced, separated by a slight
concavity; third tooth obtuse; fourth with outer
margin longitudinal or nearly so; fifth subtri-
angular, directed outward. A low granulated
swelling below interval between first two teeth.

Chelipeds quite unequal in males; carpus with
blunt internal tooth; fingers slender, pointed,
widely gaping in major chela; fitting closely in
minor, tips crossing in both; major dactyl with a
large basal tooth, color of fingers not extending on
palm.

Measurements. — Carapace: male, length, 14
mm. ; width, 22 mm.

Color. — Yellowish or brownish above, front
margin of carapace and chelipeds roseate or
tinged with bluish purple; fingers black with
paler tips. Brazilian specimens with a number of
large dark spots on upper half of chelipeds.

Habitat. — Specimens have been found near
shore on oysterbeds, under rocks, and among
sponges and bryozoan growth ; shore and shallow
water to unknown depth.

Type locality. — Barbados, British West Indies.

Known range. — South Carolina, through West
Indies and Gulf of Mexico to State of Santa
Catarina, Brazil.

Remarks. — Ovigerous females are known from
April to November in the West Indies, and

August to November in southern Brazil (Rath-
bun, 1930a, in part).

Eurypanopens depressus (Smith). Flat mud crab

Figures 179, 1831,

Panopeus depressus Smith, 1869a, p. 283.

Eurypanopeus depressus: Hay and Shore, 1918, p. 437, pi. 34,
fig. 4. — Rathbun, 1930a, p. 410, text-fig. 65, pi. 173, figs. 3-4
(rev.).

Recognition characters. — Carapace transversely
oval, approximately three-fourths as long as wide,
flattened posteriorly, convex in anterior half;
areolations well defined, finely granulate, with
several pairs of transverse rows of granulations.
Anterolateral teeth four, outer margins granu-
late; first two teeth coalesced to form broad lobe
with slightly sinuate margin; third tooth blunt;
fourth and fifth spines tipped, pointing obliquely
upward and forward. Front nearly straight,
median notch small or absent.

Chelipeds dissimilar and quite unequal. Smaller
one more rugose than larger and with margins of
fingers nearly straight and opposable for a con-
siderable distance, with opposed margins of tips
thin edged and hollowed out — "spoon shaped."
Larger cheliped with nearly smooth articles, hand
heavy and inflated; dactyl strongly curved, ob-
scurely toothed at base, and meeting immovable
finger only at tip; internal tooth of carpus tipped
with small spinule; in unworn condition both
fingers show indication of spoonlike flattening.

Measurements. — Carapace: length, 14 mm.;
width, 20 mm.

Variations. — Ryan (1956) described a persist-
ent, central, oval, blood-red spot or structure on
the inner surface of the ischium of the third
maxillipeds of both sexes. The spot is often two-
thirds the length of the article, with its surface
raised slightly above the surface of the ischium.
When pressure is applied, the hard spot cracks
and is easily dissected out. A similar spot has
been noted on P. herbstii.

The normal male abdomen is narrow with the
third, fourth, and fifth segments fused. A few
variant males have wide abdomens with seven
segments, resembling females.

Color. — Mottled grayish olive or dark olive
brown, especially on upper surfaces of chelipeds
and anterior portions of carapace; fingers dark
brown with dark color of immovable finger ex-
tended on palm; body and legs light colored un-
derneath.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

195

Figure 179. — Eurypannpeun depressus (Smith). A, ani-
mal in dorsal view, walking legs not shown ; B, large
chela in frontal view ; 5 mm. indicated.

Habitat. — In Chesapeake Bay, Ryan (1956)
found this species in greater abundance on oyster
bars than any other species of mud crab, and
evidence was presented showing a positive rela-
tionship between presence of oyster shells and this
species. Others have noted a similar habitat pref-
erence (Lunz, 1937a). In the bay, the depth range
was 1 to 15 fathoms (Cowles, 1930, in part), and
the salinity range occupied was 4.5 to 20.1 °/00.
Elsewhere the species occurs from shore to 26
fathoms.

Type locality. — New Haven, Conn.

Known range. — Massachusetts Bay through
Florida (east and west coasts) to Texas; Ber-
muda ; West Indies.

Remarks. — Ryan (1956) gave much detail on
the life history of this species in Chesapeake Bay.
Ovigerous females were collected from June to
September. Elsewhere, Rathbun (1930a) and
Lunz (1937a) reported such females in April
from Virginia and South Carolina, September

from Mississippi and the Leeward Islands, No-
vember and February from Florida. Zoeal stages
have been studied by Hyman (1925) from plank-
ton tows made in the Beaufort, N.C., area. Cost-
low and Bookhout (1961b) worked out the entire
larval and postlarval history in captivity and
illustrated four zoeal stages and a single megalops
stage. Immature males from Chesapeake Bay
ranged in width from 3.2 to 6 mm. and females
from 3.6 to 6.4 mm.

Maturity was considered to be attained at
widths of 5.1 to 6 mm. in males, and 5.5 to 6.4 mm.
in females. The mature individuals range widely
in size, up to a width of 21 mm. for females, and
ovigerous females show a range of 6 to 17 mm.
Such a broad range of sizes among mature in-
dividuals suggested to Ryan that growth and
molting continue after maturity is reached.
Maturity may be reached in the first summer
after eggs have hatched.

McDermott (1960) found that E. depressus is
a predator on oyster spat in southern New Jersey
but not so serious a pest as P. herbstii.

Genus Panopeus H. Milne Edwards, 1834

Rathbun, 1930a, p. 333.

KEY TO SPECIES IN THE CAROLINAS

a. Dark color of immovable finger continued more or less
on outer surface of palm, especially in males ; no distal
groove on carpus of chelipeds herbstii (p. 190).

aa. Dark color of immovable finger not continued on outer
surface of palm ; carpus of chelipeds with shallow
groove parallel to distal margin occidentalis (p. 198).

Panopeus herbstii H. Milne Edwards. Common mud crab

Figures 180, 183M

Panopeus herbstii H. Milne Edwards. 1834, p: 403.— Hay and
Shore, 191S, p. 437. pi. 34, fig. 9.— Rathbun, 1930a, p. 335. text-
figs. 52-53, pi. 156, figs. 1-3 ; pi. 157, figs. 1-3 (rev.).

Recognition characters. — Carapace approxi-
mately two-thirds as long as wide, regions well
marked, surface sparingly granulate. Antero-
lateral margins wTith five teeth; first two teeth
coalescent; third and fourth larger, prominent,
and with arcuate outer margins and acute tips;
fifth smaller, acute at tip and with outer margin
straight. A transverse ridge extending inward
from fifth tooth, and a shallow groove from
fourth tooth. Front wide, not produced, with
narrow median fissure; anterior margin of each
half sinuous. Male abdomen witli sides of

196

FISH AND WILDLIFE SERVICE

Figure 180. — Panopeus herbstli H. Milne Edwards. A,
animal in dorsal view, walking legs not shown ; B, right
chela in frontal view ; 5 mm. indicated.

penultimate segment nearly parallel; terminal
segment broader than long, rounded at tip.

Chelipeds heavy, finely granulate ; carpus with-
out groove on superior surface and with a blunt
internal spine; hands unequal and dissimilar,
large one with dactyl curved and strongly toothed
at base, dactyl of smaller more nearly straight ;
fingers dark, with color extending somewhat on
palm.

Measurements. — Carapace: male, length, 26
mm.; width, 38 mm.

Variations. — Rathbun (1930a) separated this
species into a number of forms on the basis of
structural characteristics but considered these the
result of response to environment rather than
genetic differences. Intermediates may occur in
any locality; thus, the forms are not always
easily separated.

Ryan (1956) described a persistent, central,
oval, red spot or structure on the inner surface of
the ischium of the third maxillipeds of both sexes.
Mrs. Peggy Keney of the U. S. Fish and Wildlife
Service Bureau of Commercial Fisheries, Bio-
logical Laboratory, Beaufort, N.C., found this

spot to occur on 100 percent of males and 55
percent of females in the Beaufort area. A sam-
ple of 596 specimens was examined.

Habitat. — Depth distribution for the species
ranges from the intertidal zone to 12 fathoms.
Ryan (1956) found the species to be rare in
Chesapeake Bay in a salinity range of 13.95 to
19.04 °/00. Tlie depth distribution there was 2 to
6 fathoms and at each collection spot the bottom
was composed of soft mud with few oyster shells.
McDermott and Flower (1953) found the species
common on oyster beds in Delaware Bay, where it
commonly cracks and eats small oysters and the
barnacle Balanus eburneus. The toadfish was con-
sidered a common predator.

In North Carolina and South Carolina, this is
one of the most common crabs of estuarine re-
gions, found wherever the bottom is muddy or
covered with shells or stones. In some localities
along edges of the higher marshes, it is found in
burrows and is frequently associated with Sesarma
reticulata and Uca minwx.

In the West Indies, collections have been made
from mangrove roots, sponges, and coral reefs.

Type locality. — North America.

Known range. — Boston, Mass., to State of
Santa Catarina, Brazil; Bermuda.

Remarks. — This common xanthid crab has a
fossil record dating from the Miocene in North
America, and the genus Panopeus has a record
extending from the Eocene to the present (Rath-
bun, 1935).

Ovigerous females are known virtually the year
around in Florida. They are known through late
spring and summer in the Carolinas, in July in
Maryland, February to September in various
parts of the West Indies, and August to October
in southern Brazil.

Ryan (1956) gave carapace widths of mature
males as 8.3 to 37.3 mm., and of mature females
as 21.6 to 27.8 mm. A specimen 45 mm. wide was
found at Beaufort, N.C., in 1960 (Mrs. Keney,
personal communication), and Wass (1955) re-
ported a male 55 mm. wide.

Costlow and Bookhout (1961a) reviewed early
descriptions of larvae and described and illus-
trated four zoeal and one megalops stage reared
in the laboratory.

Costlow, Bookhout, and Monroe (1962) reared
the larval stages under 12 different conditions of

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 0—65 14

197

salinity and temperature. Eggs were maintained
in salinities of 12.5, 20.1, 26.5, and 31.1 %„ and
all larvae hatched as first stage zoeae. Succeeding
stages showed higher percentages of survival un-
der different conditions, with shortest develop-
ment time in the highest salinity. The lowest
salinity tested did not permit development to be
completed. In addition, low temperature affected
duration of all larval stages and mortality of
some stages. Larval development was completed
to first crab in 48-52 days at 20° C, in 18-28
days at 30° C. From data, the effects of salinity
and temperature on mortality of larval stages
were projected by statistical methods over a wide
range of combinations. The hypothesis is pre-
sented that the effect of temperature on successive
larval stages limits the productive spawning
period. Low temperatures favor the spring brood
of larvae [in these latitudes], prolonging larval
development until warmer water produces favor-
able conditions for the megalops stage. Larvae
hatched in fall are not so favored and mortality
in late zoeal and megalops stages would be high.

In a study of the relationship of habitat to oxy-
gen consumption by estuarine crabs, Ayers ( 1938 )
found P. herbstii to be intermediate in a scale of
partial adaptation of the respiratory mechanisms
to life in air. Teal (1959) found this species
active on Georgia marshes when the tide was high
or the sky cloudy. When the marsh was exposed,
it was found in burrows, usually near the top, in
air or water. Among various marsh crabs studied
(see remarks, TJca minax) only P. herbstii was
active at temperatures below 12° C. Respiration
in this crab was most affected by reduced oxygen
pressure among species tested, showing a rate re-
duction of 90 percent at 4 mm. Hg.

Menzel and Nichy (1958) found that P. herb-
stii and Miiiijijir iiierceiiiiria are the only xanthids
large enough to kill significant numbers of adult
oysters. McDermott (I960), studying predatory
activities of xanthid crabs on oyster beds in New
Jersey, found thai /'. herbstii destroyed 1- and 2-
year-old oysters at a rate of 0.15 oysters per end)
per day. The crab also preyed actively on oyster
spat as well as barnacles (B alarms improvisus) .
He concluded that P. herbstii is potentially the
most destructive of the five species of mud crabs
occurring on New Jersey oyster beds.

Panopeus occidentalis Saussure

Figures 181, 183N

Panopeus occidentalis Saussure, 1857, p. 502. — Rathbun.
1930a, p. 348, text-fig. 55; pi. 161. figs. 1-3 (rev.).

Recognition characters. — Similar to Panopeus
herbstii, but differing in having more convex cara-
pace, especially in gastric region; front narrow,
advanced; second anterolateral tooth usually nar-
rower and separated by deeper sinus from first
tooth, third to fifth teeth thicker, more prominent
and widely separated, third one blunt, forming
almost a right angle at tip; abdomen of male
wider, sides of penultimate segment not parallel,
narrowed toward proximal end.

Carpus of chelipeds with groove parallel to
distal margin, sometimes rugose; dark color of
immovable finger not continued on palm. Walking
legs somewhat longer and more slender.

Measurements. — Carapace: male, length, 23
mm. ; width, 33 mm. Smaller than P. herbstii.

Variations. — There is considerable variation
even in a single lot of specimens. The carapace
may be smooth and shining, or with light, granu-
late, transverse lines; the second anterolateral
tooth may be small, subacute, and similar to the
first rather than broadly rounded and large; the
female abdomen may have sides of the sixth seg-
ment parallel instead of converging slightly to-
ward the proximal end. Variations in teeth of the
anterolateral border were noted in 12 percent of
females studied by de Oliveira (1940). In these
the first, second, and third teeth of one side were
depressed, giving the impression of but one sinu-
ous tooth while those of the other side were
normal.

This species, like P. herbstii. has 'been divided
into two environmental forms (typical and ser-
rate), and both occur in the Carolinas (Rathbun,
1930a).

Cot or. — Carapace dull yellow spotted with
brown and red; legs yellow with brown macula-
tions and speckles on chelipeds; walking legs with
brown or rose streaks. De Oliveira (1940) gave
color of the species in Brazil as: carapace dark
yellow with red blotches or chocolate varying in
tone; legs same color but spotted with reticulated
points, points of lingers chocolate to almost black ;
body yellow ventrally, legs yellow to grayish:
some rare specimens completely yellow.

198

FISH AND WILDLIFE SERVICE

Figure 181. — Panopeus occidentalis Saussure. Animal
in dorsal view, legs of left side not shown, 10 mm.
indicated.

Habitat. — This species has been found among
rocks, mangrove roots, sponges, ascidians, and sea-
weed, and on pilings of piers along shore; shore
to 10 fathoms.

Type locality. — Guadeloupe.

Knoivn range. — North Carolina to State of
Santa Catarina, Brazil; West Indies and Ber-
muda.

Remarks. — DeOliveira (1940) reported in some
detail on the natural history of this species where
it occurs in the vicinity of the Ilha Pinheiro, neai
Rio de Janeiro, Brazil. The species is primarily
crepuscular or nocturnal and is found living
chiefly in ditches, between and beneath stones, and
among mangrove roots, often burrowing to a
depth of 30 cm. Both sexes were found together
except when the eggs were deposited, and then
females were not so often seen. Molting individ-
uals and copulating pairs were rarely found.

Mating pairs were found from November to
December, and on one occasion in water of 22
°/00 at 22° C. Periods of egg deposition ex-
tended from January to May, and again from
July to August (September, Rathbun, 1930a). (In
the Caribbean area ovigerous females are known
from January to July, U.S. National Museum
records.) The seldom-seen ovigerous females bore
dark, chocolate colored eggs. Such females showed
a range in carapace width from 13.3 mm. to 35.2

mm., and bore 3,000 to 70,000 eggs, depending on
size. Females were observed to aerate and clean
the eggs in water at low tide in the evening. Eggs
in the laboratory hatched in about 15 days. Molt-
ing of females followed hatching of eggs.

Young of the species were found throughout the
year, as others have noted. One large male meas-
ured 48.2 mm. [width], though the average dimen-
sion for the typical form was 27.7 mm. long by
40.5 mm. wide; for the serrate form, 19.9 mm.
long by 27.5 mm. wide.

The species was believed to have few natural
enemies. Material from the gut was found to con-
sist of a variety of plant and animal matter. In
addition to the ecological discussion, de Oliveira
gave a number of observations on autotomy and
its effect on movement and behavior.

Genus Eurytium Stimpson, 1859

Rathbun, 1930a, p. 422.— Hemming, 1958b, p. 32.

Eurytium limosum (Say)

Figures 182, 183 O

Cancer limosa Say, 1818, p. 446.

Eurytium limosum: Hay and Shore, 1918, p. 438, pi. 35, fig.
7.— Rathbun, 1930a, p. 423, pi. 176, figs. 1-2 (rev.).

Figure 182. — Eurytium limosum (Say). A, animal in
dorsal view : B, large chela in frontal view ; 10 mm.
indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

199

Figure 183. — Tips of right first pleopods of male xanthids; A, Glyptoxantliiis erosus (Stirupson), medial view; B.
Carpoporus papnlosus Stimpson, medial view; C, Rhithropanopeus harrisii (Gould), medial view; D, Hexa-
pannpcus angustifrons (Benedict and Rathlmn), medial view; E, Hexapanopeus paulensis Rathlmn, medial view;
P, Neopanopc texana texana (Stimpson), medial view; G, Ncopanope texana sayi (Smith), medial view;'
H, Leptodius agassizii Milne Edwards, medial view; I, Micropanope exwithiformis (Milne Edwards), abdominal
view; J, Micropanope nuttingi (Rathbun), medial view; K, Eiirypanopeus aobreviatus (Stimpson), medial view;
L, Eurypanopeus depressus (Smith), medial view; M, Panopeus herbstii H. Milne Edwards, medial view; N, Pano-
peus occidentalis Saussure, medial view; O, Eurytium limosum (Say), medial view; 0.5 mm. indicated for all
■figures, except I and J twice this magnification, and O one-half this magnification.

Recognition characters. — Carapace broad, ap-
proximately 1.5 times as wide as long, quite convex
from front to back, nearly plane from side to
side ; surface smooth to eye but under a lens finely
granulate, granulations coarser near frontal and
anterolateral margins. Front approximately one-
fourth width of carapace, divided into two lobes
by a median notch giving rise to a shallow groove
disappearing over gastric region. Orbital margins
somewhat elevated; external orbital tootli coa-
lesced with Hist tootli of anterolateral border, di-
vision between these teeth indicated by a shallow
h. Anterolateral teetli witli raised margins,
second and third teeth rounded at tip, fourth more
prominent and subacute.

Chelipeds massive, unequal, and dissimilar,
more so in male than in female .;. merus with
coarsely tuberculate superior border and a distal
spiniform tooth; carpus with a narrow internal
spine, not grooved; fingers pointed, deflexed, with
large basal tooth on major dactyl.

Measurements. — Carapace: length, male, 2\
mm. ; width, 36 mm.

Color. — Carapace brilliant purplish blue, dark
gray, or black; carpus and hand bluish; proximal
upper half of dactyl pink or purple; remainder of
fingers porcelain white; lower portion of che-
lipeds, and also carpal teetli, yellow or orange;
color of fingers not continued on palm.

Habitat. — This primarily tropical species lives
in muddy or marshy banks a bit below t lie high-

200

FISH AND WILDLIFE SERVICE

tide mark in burrows partially filled with water,
among stones at the high-tide mark, in burrows in
sand, under stones between tides, and on coral
reefs (Rathbun, 1930a). High-tide mark to shal-
low depths near shore.

Type locality. — "Inhabits shores of the North-
ern States."

Known range. — Modern records, South Caro-
lina to State of Sao Paulo, Brazil; Bermuda.
Formerly reported from New Jersey (Ryan,
1956).

Remarks. — This species has a fossil record in
North America dating from the Miocene of North
Carolina and Florida (Rathbun, 1935).

Teal (1959) found this species active on Geor-
gia marshes when the tide was high or the sky
cloudy. When the marsh was exposed, it was
found in burrows, usually near the top, either in
air or water. Respiration rates in water were
higher than in air. The species showed internal
regulation of metabolism in that it was independ-
ent of oxygen tension but not of acclimation to
temperature.

Ovigerous females have been reported from
Florida in August (Wass, 1955) .

Family Goneplacidae

Palp of external maxillipeds articulating at or
near anterointernal angle of merus; exognath nor-
mal in size, not concealed. Antennular septum a
thin plate. Division of orbit into two fossae us-
ually not indicated. Genital ducts of male usually
perforating base of last pair of legs, often passing
through a groove in sternum.

This group has a general resemblance to the
Xanthidae in body shape. Members of the group
are all bottom dwellers.

KEY TO GENERA AND SPECIES IN THE
CAROLINAS

a. Base of third segment of male abdomen covering whole
space between last pair of legs ; carapace subquadrate,
widest between postorbital angles ; anterior border en-
tirely occupied by square-cut front, and orbits formed

into long, narrow trenches Goneplax hirsuta (p. 201).

aa. Base of third segment of male abdomen not covering
whole space between last pair of legs,
b. Frontoorbital width almost as great as total width
of carapace : eyestalks long : carapace subquadrate,
posterolateral margins converging

Euryplax nitida (p. 202).
bb. Frontoorbital width from one-half to three-fourths
total width of carapace : eyestalks short ; anterolat-
eral margins arcuate

Speocarcinus carolincnsis (p. 202).

Genus Goneplax [Leach, 1814]

Rathbun, 1918b, p. 25.— Hemming, 1958a, p. 32.

Goneplax hirsuta Borradaile

Figure 184

Ooneplax hirsuta Borradaile, 1916, p. 99, fig. 11. — Rathbun,
1918b, p. 28, text-fig. 7 (rev.).

Recognition characters. — Carapace approxi-
mately two-thirds as long as broad, greatest width
between tips of postorbital spines; regions faintly
marked except for H-shaped depression in middle.
Sides converging backward from prominent,
sharp, postorbital spines ; armed with sharp spine
near postorbital spine. Front almost straight, with
low rostral prominence in broad, shallow median
notch. Orbital margin sinuous, sloping backward,
width of orbit and front nearly equal.

Chelipeds almost equal ; merus about two-thirds
length of carapace, deep, with a spine a little be-
yond middle of upper edge ; carpus broader than
long, with a stout internal spine. Hand longer
than remainder of limb; fingers about equal to
palm, irregularly toothed, not gaping; external
base of hand and distal half of carpus with a
long dense tuft of hair, fringe of similar hairs
along inner side of merus. Walking legs slender,
meri smooth or fringed with light pubescence, dis-
tal articles fringed with hairs.

Measurements. — Carapace: male, length, 19
mm. ; width, 29 mm.

Habitat. — Forty to eighty fathoms.

Figure 184. — Goneplax hirsuta Borradaile. A, animal in
dorsal view : B, right chela and carpus in outer view ;
approximately X 1.75 (after Borradaile, 1916).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

201

Known range. — North Carolina to Rio de
Janeiro, Brazil.

Remarks. — Ovigerous females have been taken
in the Gulf of Mexico off Florida in June (U.S.
National Museum records).

Genus Euryplax Stimpson, 1859

Rathbun, 1918b, p. 34. — Hemming, 1958b, p. 32.

Euryplax nitida Stimpson

Figure 185

Euryplax nitida Stimpson, 1859, p. 60.— Rathbun, 1918b, p. 34,
text-fig. 11, pi. 7 (rev.).

Recognition characters. — Carapace smooth and
shining, convex. Front deeply notched on each
side at insertion of antennae; interantennal mar-
gin nearly straight. Anterolateral margins con-
verging anteriorly, less than half as long as
posterolateral margins and armed with three
strong teeth including outer orbital. Carapace
widest at level of third tooth.

Merus of chelipeds in male with a deep round
pit at anterior distal corner of lower surface, pit
surrounded by a fringe of long hair, and with a
sharp curved spine near distal end of upper sur-
face; carpus with a sharp inner spine and inner
surface pilose. Walking legs slender.

Fioubb is.-,. Euryplax nitida Stimpson. .Male in dorsal
view, legs of left side nol shown, ■". mm. indicated.

Female with narrower carapace; chelipeds more
nearly equal, and merus lacking pit with sur-
rounding hair.

Measurements. — Carapace: male, length, 15
mm. ; width, 25 mm.

Color. — Distal half of fingers white (Rathbun,
1918b).

Habitat. — Shallow water to 49 fathoms.

Type locality. — Florida Keys.

Known range— OR Beaufort, N.C., to Texas;
West Indies to St. Thomas ; Bermuda.

Remarks. — Ovigerous females have been taken
in June from southern Florida.

Genus Speocarcinus Stimpson, 1850

Rathbun. 1918b, p. 38.— Hemming, 1958b, p. 37.
Speocarcinus carolinertsis Stimpson

Figure 186

Speocarcinus carolinensU Stimpson. 1859, p. 59, pi. 1, figs.
1-3. — Rathbun, 1918b. p. 39, pi. 8, pi. 159, fig. 6 (rev.).

Recognition characters. — Carapace subcylindri-
cal, nearly smooth, punctate, obscurely granulate
near margins, pubescent; gastric region and sub-
divisions well denned. Anterolateral margin witli
five teeth including outer orbital; second tooth
rounded and not always separated from first ; last
three teeth sharp, well defined. Posterolateral
margins parallel. Front approximately one-fourth
width of carapace, sinuous, nearly straight, with
median emargination. Eyestalks constricted near
cornea.

Chelipeds strong, nearly smooth, margins
hairy; merus with a strong spine on upper bor-
der; carpus granulate internally and with a blunt
internal tooth ; hand with outer surface smooth,
microscopically granulate; dactyl with stout
tooth at base. Walking legs with hairy margins.

Measurements. — Carapace: male, length, •!'■)
mm., width, 29 mm.: female, length, IT mm.,
width, 27 mm.

Habitat. — "This crab lives in the subterranean
galleries excavated in the mud at low-water mark
by the Sguilla, Callianassa, and other Crustacea,
or by large worms," (Stimpson in Rathbun,
1918b) ; near low-tide mark to 76 fathoms.

Type locality. — Charleston Harbor. S.C.

Known range. — South Carolina through Gulf
nf Mexico and West Indies to Surinam.

202

FISH AND WILDLIFE SERVICK

Figure 186. — Speoearcinus carolinenHs Stimpson. Type
female in dorsal view (after Rathbun, 1933).

Family Pinnotheridae

Carapace often somewhat membranous. An-
terolateral margins entire or very slightly den-
tate. Front, orbits, and eyestalks very small, cor-
nea often rudimentary. Buccal cavity usually
wide, often semicircular in outline. Merus of third
maxilliped never quadrate, and never with palp
distinctly at anterointernal angle; ischium small,
absent, or fused with merus and directed obliquely
inward (Rathbun, 1918b).

Small crabs living as commensals or parasites
in bivalve mollusks, ascidians, worm tubes, and on
or in echinoderms. Free living or migratory stages
are occasionally taken in open water.

KEY TO GENERA IN THE CAROLINAS

a. Dactyls of walking legs simple, acute.

b. Third walking leg little, if any, longer than other
legs.

e. Carapace suborbicular and somewhat membranous
in mature female, flattened and firm in hard stage
male and female buccal mass subquadrate

Pinnotheres (p. 203).
cc. Carapace oval, flattened, and rather firm ; buccal

mass subtriangular Parapinnixa (p. 208).

bb. Third walking leg longer and stronger than others,

often considerably so Pinnixa (p. 210).

aa. Dactyls of first, second, and third walking legs bifur-
cate DissodaetyUis (p. 209).

Subfamily Pinnotherinae

Carapace usually not markedly transverse.
Ischium of external maxillipeds either rudimen-
tary or indistinguishably fused with merus to
form single piece, usually oblique, occasionally
nearly transverse; palp not so large as merus-
ischium (Rathbun, 1918b).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Genus Pinnotheres Bosc [1801 or 1802]

Rathbun, 1918b, p. 62. — Hemming, 1958b, p. 36.

KEY TO SPECIES IN THE CAROLINAS

Hard-stage males and females

a. Carapace with a striking pattern of light spots on dark

background of pubescence maculatus (p. 206).

aa. No striking color pattern ostreum (p. 203).

Posthard females (and male maculatus)

a. Carapace nearly naked ostreum (p. 203).

aa. Carapace covered with a short deciduous pubescence

maculatus (p. 206).

Pinnotheres ostreum Say. Oyster crab
Figures 187, 188, 189

Pinnotheres ostreum Say, 1817, p. 67, pi. 4, fig. 5. — Rathbun,
1918b, p. 66, text-fig. 30 : pi. 15, figs. 3-6 (rev.). — Hay and Shore,
1918, p. 443, pi. 35, fig. 9.

Pinnotheres depressum Say, 1817, p. 68.

Pinnotheres depressus: Rathbun, 191Sb, p. 79, pi. 17, figs. 1-2
(rev.).

Recognition characters. — Mature female : Cara-
pace subcircular in outline; surface glabrous for
most part, smooth, shining, membranous, yielding
to touch, convex from front to back and with a
broad, shallow, longitudinal depression at each
side of cardiac and gastric areas. Lateral margins
thick and bluntly rounded; posterior margin
broad. Front rounded, slightly produced, cover-
ing and concealing eyes. Orbits small, subcircular,
anteriorly placed. Antennule large ; antenna small,
flagellum not so long as diameter of orbit. Buccal
mass roughly quadrangular in outline but bent
into broad crescentic arch, short anteroposteri-

Figuee 1ST .—Pinnotheres ostreum Say. Mature female
in dorsal view, 5 mm. indicated.

203

Figure 188. — Pinnotheres ostreum Say. A, stage I female
in dorsal view ; B, stage I female in ventral view ; ap-
proximately X 9 (after Stauber, 1945).

Figure 189. — Pinnotheres ostreum Say. Male in dorsal
view, walking legs of left side not shown, 1 mm. indi-
cated.

orly. Outer niiixilliped with ischium and merus
fused: carpus, or first article, of palp short, ob-
long; propodus elongate, end rounded; dactyl
inserted behind middle of propodus, minute,
si i> n dei-.

Chelipeds small ; merus and carpus rather slen-
der. Palm somewhat flattened inside, swollen
outside, strongly widened from proximal toward
distal end, then narrowed; width across base of
Angers less than greatest width of palm; fingers,
especially immovable one, stout, not gaping, tips
hooked past each other, minute teeth on opposed
edges, a larger tooth near base of each, immovable
finger horizontal. Walking legs slender, subcylin-
drical; last two articles with thin fringe of hair;
second and third legs about equal in length, first
legs slightly stouter, last pair turned backward
and upward.

Abdomen large, extending beyond carapace in
all directions.

Measurements. — Carapace : width, ranging from
4 to 15 mm. (Christensen and McDermott, 1958).

Color. — Whitish or salmon pink.

Recognition characters. — Mature male and
hard-stage female : Carapace well calcified, flat
dorsally, subcircular in outline, with truncate
front more advanced than in mature female.
Posterior margin straight ; lateral margin thin,
rather sharply bent from dorsal side, margin
marked by a raised band of short dense hair. Eyes
well developed. Buccal mass crescentic, arched,
broad from side to side but short anteroposteri-
orly; cavity completely closed by external maxih
lipeds formed as in mature female.

Chelipeds stout; merus and carpus not slender
as in mature female. Palm slightly flattened in-
side, swollen outside, and shaped as in mature
female, both margins convex. Hand with bands
of pubescence on upper and outer surface of palm,
and outer surface of immovable finger. Fingers
stout, especially immovable finger, with tips
hooked past each other when closed; dactyl with
small tooth proximally, tooth fitting between two
protuberances on immovable finger when closed;
both fingers with stiff hairs on gripping edges.
Walking legs flattened, with posterior margins
thickened, and with plumose swimming hairs on
second and third pairs.

Abdomen narrow, confined to sternal depres-
sion; copulatory stylets of male well developed,
first pair bladelike and hairy, second pair rodlike
and almost hairless (Stauber, 11)45).

204

FISH AND WILDLIFE SERVICK

Measurements. — Carapace: male, width, 1.4 to
4.6 mm.; female, width, 1.3 to 2.7 mm. (Christen-
sen and McDermott, 1958) .

Color. — Dark or medium-dark brown with two
large, distinct, almost circular, pale white spots on
both carapace and sternum; dorsal spots on bran-
chial regions, ventral spots flanking abdomen and
medial to first pair of legs; color and spots per-
sistent in alcohol (various authors) .

Habitat. — Parasitic [or commensal] chiefly in
the oyster, Crassostrea virginica, also in Pecten
spp. and Anomia simplex (Christensen and Mc-
Dermott, 1958), and in Mytilus edulis (McDer-
mott, 1961). Also occasionally found in Chaetop-
terus tubes (Gray, 1961).

Type locality. — Given as — "inhabiting the com-
mon oyster."

Known range. — Salem, Mass., to State of Santa
Catarina, Brazil.

Remarks. — Say's P. depressus appears almost
certainly to be the hard-stage male as described
above and discussed below.

The works of Hyman (1924a), Stauber (1945),
Sandoz and Hopkins (1947), and Christensen and
McDermott (1958) together have made knowledge
of the biology and life history of P. ostreum the
most complete for any species of Pinnotheres in
the world. The serious student should refer to
these thorough works, for they can be summarized
only in barest outline here. The complex life
cycle of this species encompasses many develop
mental stages, as well as a striking sexual dimor-
phism in the mature animals, which, together with
the structural specializations and mode of exist-
ence, demonstrate a beautiful accommodation to
an unusual habitat.

The larval stages include four zoeae followed
by one megalops. The first two zoeal stages were
described by Hyman (1924a), and a description
of all these stages (partial for fourth zoeal stage)
was given by Sandoz and Hopkins (1947). In
general, the zoeae and megalops have no dorsal or
lateral spines on the carapace. Time of develop-
ment from hatching to molting of the megalops to
first crab stage is 25 days.

From the first crab stage on, development is
summarized by Christensen and McDermott
(1958, p. 154). The first crab stage, actually the
stage which invades oysters, is called the invasive
stage by these authors. It was described by Sandoz

and Hopkins (1947) and in many respects is simi-
lar to the later hard stage in its flattened shape,
legs adapted for swimming, and characteristic
color markings (carapace width, 0.59-0.73 mm.).

In Delaware Bay, few invasions take place be-
fore August 1. The peak of oyster setting there is
in July; spat will have grown to size sufficient to
harbor one or more crabs by the peak of the crab
invasions in September. Though invasive stages
in oysters are found all winter, growth and devel-
opment stop about the first of November when
water temperatures begin to drop below 15° C.
Surprisingly small spat may be invaded. Two
crabs were found in an oyster 4.2 mm. long, and
in larger spat up to seven crabs were found in a
single specimen. The crabs prefer to invade spat
or yearling oysters rather than older ones (76.7,
54.6, and 21.5, being respective infestation per-
centages for a given year class of crabs), but
survival rate of crabs is better in yearlings and
older oysters.

Following the invasive stage are two ill-defined
stages designated as prehard. These stages, de-
scribed by Christensen and McDermott (1958),
are soft and resemble later posthard stages of the
females (carapace width: male, 1.4-4.6; female,
0.75-2.7 mm.). The legs are rounded and not
adapted for swimming. These stages are found in
all parts of the water-conducting system of in-
fested oysters. In the region of Delaware Bay,
most young crabs reach the prehard stages before
growth ceases in fall and they overwinter in these
stages. Development resumes when temperatures
rise above 15° C.

The hard stage, formerly regarded as the inva-
sive stage, is characterized above. On the average,
males are larger than females, as they are in the
preceding stages. The form of this stage resem-
bles that of the invasive stage, and males of this
stage swim freely. This is the copulatory stage,
and the males normally die in this stage.

The succeeding female stages, described by
Stauber (1945), resemble the adult female, and
are found only in the host on the gills. Stage II
(the hard stage was designated as stage I by
Stauber) has a thin flexible carapace but a narrow
abdomen contained wholly in the sternal groove
(carapace width, 1.3-3.1 mm.). Stage III has an
abdomen extending beyond the depression in the
sternum (carapace width, 2.6-4.4 mm.). Stage IV

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

205

has a relatively wide abdomen reaching the coxae
of the legs in most cases (carapace width, 3.6-
8.9 mm.). Stage V is the adult female described
above.

The posthard stages are passed through rapidly.
In Delaware Bay by mid-July, 62 percent of
females have developed from the overwintering
stage to maturity. By mid-August, 95 percent are
mature and more than half are ovigerous; thus,
P. ostrevm reaches maturity within its first year.
Males live 1 year or less, but females continue to
grow after they have hatched their first batch of
eggs and may live to an age of 2 or 3 years, though
many probably die after they have hatched their
eggs in the second summer. In the second or third
year, females may become ovigerous as early as
mid-June, and ovigerous yearlings may occur as
late as mid-October. Farther south the breeding
season is more extended, and ovigerous females
have been collected near Ocracoke, N.C., as early
as mid-April.

Ovigerous females measuring 9.4 and 10.8 mm.
in width carried 7,957 and 9,456 eggs respectively.
It is not known how long a female carries eggs,
but it is believed to be 3 to 5 weeks. The females
produce only one batch of eggs the first year but
in a second or third year may produce twice.

Except for the. brief free-swimming periods in
the invasive hard stages, the crabs lead a parasitic
existence. Stauber (1945) and Christensen and
McDermott (1958) both found that the crab feeds
on food filtered from water by the host by picking
food strings from the margins of the gills with its
chelipeds. The crab also will catch newly formed
mucus-food masses with its walking legs and
then reach beneath the abdomen with its chelipeds,
comb the legs, and pass the food on to the mouth.
The method of feeding for young crabs not on the
gills is unknown, but they may filter food with
the mouth parts. Posthard stages are found only
on the gills, indicating that feeding on the food-
laden mucus alone can insure adequate food for
rapid growth and egg production. Growth of
females is positively correlated with size of host
and is probably related to food supply and
amount of water pumping by the host.

The ordinary feeding activities are harmful to
the host ( Stauber, 1945), particularly causing gill
erosion of two types, local erosion of one or more
demibranchs, and an extensive shortening of denii-

branchs from the anterior end of gills to a point
ventral to the adductor muscle. Christensen and
McDermott (1958) noted that this erosion is a
progressive process and nearly all infested oysters
show some gill damage, some few older oysters
having hardly any gill tissue left. Usually, how-
ever, only presence of a mature crab over a long
time will noticeably affect growth of an oyster in
normal environmental circumstances.

Pinnotheres tnaculatus Say. Mussel crab
Figure 190

Pinnotheres maculatum Say, ISIS, p. 450.

Pinnotheres tnaculatus: Rathbun, 191Sb, p. 74, text-figs. 35-36,
pi. 17, figs. 3-6 (rev.).— Hay and Shore, 1918, p. 443, pi. 35,
fig. 10.

Recognition characters. — Mature female: cara-
pace suborbicular, somewhat broader than long,
thick and firm but not hard, convex, smooth; sur-
face uneven, covered with a short, dense, decidu-
ous tomentum. Gastrocardiac area higher than,
and separated by depressions from, branchio-
hepatic area. Front slightly advanced, approxi-
mately one-fifth width of carapace, subtruncate
in dorsal view, slightly bilobed. Orbits small,
subcircular, eyes spherical. Antenna longer than
width of orbit; antennule large, obliquely trans-
verse. Buccal mass roughly quadrangular, cres-
centic, much broader than long; ischium and
merus of external maxilliped united; propodus
larger than carpus; dactyl narrow, curved, spatu-
late, attached near middle of propodus, and
reaching to near extremity of propodus.

Chelipeds moderately stout, articles subcylin-
drical and more or less pubescent; carpus elon-
gate; palm thick, blunt edged, increasing in size
distally ; fingers stout, fitting closely together with
tips hooking past each other; immovable finger
nearly horizontal ; dactyl with tooth near base fit-
ting into sinus with tooth at either side on immov-
able finger. Walking legs slender, hairy above
and below; second pair longest, shorter than che-
lipeds; first three dactyls falcate, shorter than
propodi ; last leg shortest, turned forward and
upward, with long dactyl equaling propodus.

Abdomen large, extending to bases of legs.

Measurements. — Carapace: length, 13.7 mm.:
width, 14.3 mm.

Color. — Obscure brown.

Recognition characters. — Mature male: Cara-
pace flat, subcircular, diameter about half as great

206

FISH AND WILDLIFE SERVICE

Figure 190. — Pinnotlicrc.s- maculatus Say. Upper draw-
ing : male in dorsal view, 2 nun. indicated : Lower draw-
ing : female in dorsal view, 3 mm. indicated.

as female, somewhat longer than wide, harder
than female. Kegions superficially defined more
by color than by structural prominence, light
areas mostly elevated, usually allowing pubescence
to wear; gastric, cardiac, and branchial regions
separated by broad, shallow, confluent indenta-
tions. Front broad, prominent, depressed, slightly
bilobed, approximately one-third width of cara-
pace. Orbits subcircular, eyes large. Antennae
somewhat longer than width of orbit.

Chelipeds shorter than in female, hands
stouter. Walking legs wider, especially propodal
articles of first three legs ; posterior surface over-
laid with thin fringe of hairs attached near upper
margin ; last leg relatively shorter than in female,
not reaching propodus of third, dactyl more
nearly like third than in female.

Abdomen at middle approximately one-third
width of sternum, gradually narrowing from

third to seventh segment, sides of third convex,
of seventh obtusely rounded ; sutures between seg-
ments of abdomen and sternum with narrow lines
of dark pubescence.

Measurements.— Carapace : length, 9.1 mm.;
width, 8.7 mm.

Color. — Striking light dorsal color pattern of
bare spots on a background of dark pubescence
consisting of a median stripe constricted in mid-
dle and behind, a subtriangular spot on each side
in front of middle, and a linear spot on each
side behind. Chelipeds with dark pubescence on
inner and upper surface of carpus, a bit on upper-
surface of merus and inner side of palm proxim-
ally, otherwise scattered flecks on hands and walk-

ing legs.

Variations. — Young females resemble dark-
colored males except in shape of the abdomen and
the character of its appendages. Such females are
free swimming and range upward in length to
5.2 mm. More mature females, light colored and
commensal or parasitic in habit, range from 3.3
mm. in length upward. In such small and medium
sized females the long hair on the legs persists.

Some males resemble mature females in colora-
tion and structure of legs, ranging in length from
about 4 mm. upward. Such males are commensal
or parasitic in habit.

Individuals vary in stoutness of chelae, and in
length and curvature of dactyls on the second
legs. Normally this dactyl is like the dactyls on
the first and third legs, but may be straightened
and longer, and may occur on one or both sides of
an individual and in different individuals in the
same lot.

Habitat. — Mature males and females are com-
mensal or parasitic in Mytilus edulis, Modiolus
modiolus, M. americanus, Mya arenaria, Aequi-
peeten gibbus, A. irradians, Placopecten magel-
lanicus, oyster (?), Atrina serrata, and in tubes
of Chaetopterus variopedatm, from Molgula ro-
busta, the pharynx of Bost richobranchus pilularis,
and on Asterias vulgaris. The free-swimming
stages have been found in bays and sounds. Sur-
face to 25 fathoms.

Type locality. — Given as — "inhabits the muri-
cated Pinna of our coast."

Known range. — Off Marthas Vineyard, Mass.,
to Mar del Plata, Argentina.

Remarks. — Though no detailed life-history
studies have been made on this species comparable

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

207

to those on P. ostreum, more incidental data are
available on mature individuals of both sexes
from casual collecting. Ovigerous females have
been found through most of the range of distribu-
tion. They have been reported in January from
St. Thomas, March from Jamaica, May to Novem-
ber from Florida, June to January from North
Carolina, July to September from Massachusetts
and Rhode Island, and in June in Brazil (Rath-
bun, 1918b, and U.S. National Museum records).
Hyman (1924a) described the first stage zoea
which, unlike the zoeae of P. ostreum, has well-
developed spines on the carapace. These zoeae are
common near Beaufort, N.C., throughout the
summer.

As in P. ostreum, the hard stage is found in
both males and females and, though both swim
actively, the males predominate in open water. An
invasive stage may precede the relatively large-
hard stage as in P. ostreum. Unlike P. ostreum
males, at least some P. maculatus males appar-
ently live beyond the hard stage, for larger, some-
what globose males, resembling females in adap-
tation to parasitic or commensal life, occur in
some hosts (see variations above).

Welsh (1932) found the swimming velocity of
P. maculatus larvae to be greatly influenced by
temperature and light intensity. The larvae are
sensitive to only a small range of light intensity.
At temperatures between 20° and 25° C. the maxi-
mum velocity of swimming is attained at inten-
sities between 10 and 25 meter-candles. When
series of measurements are made to determine the
effective light at different constant temperatures,
it is found that, besides a marked effect on general
activity, there is a change in the relationship of
velocity to intensity ; slopes of curves showing
these relationships change, and the maximum pos-
sible velocity of swimming for each temperature is
readied earlier at the higher temperatures.

Genus Parapinnixa Holmes, 1894

Rathbun, 1918b, p. 107.
Parapinnixa bouvieri Rathbun

Figure 191

Parapinnixa bouvieri ltnthbun. 1918b, p. Ill, tp\t fig. 60, pi.
2.r., flKs. 4 10.

Recognition characters. — Minute. Carapace
smooth, shining, not more than twice as wide as
long, longitudinally very convex, slightly convex

Figure 191. — Parapinnixa bouvieri Rathbun. Ovigerous
female in dorsal view, legs of left side not shown, 1 mm.
indicated.

transversely, sides arcuate; widest part with a
thin pubescent margin on lower edge; anterior
margin nearly straight, a row of four distant pits
behind margin. Frontoorbital width about one-
third carapace width. Front broadly triangular,
deflexed, tip invisible in dorsal view, edge emargi-
nate and pubescent ; a pubescent groove running
parallel to and immediately behind front termi-
nating in orbital margins. Orbits circular, filled
by eyes, cornea black, visible from above. An-
tennular cavities large, not wholly separated from
each other or from orbits, and extending laterally
beyond minute antennae. Outer maxilliped tri-
angular when folded in place, two free corners
rounded, longitudinal side approximately two-
thirds as long as posterior side; ischium and
merus fused, obliquely truncate distally leaving
first joint of palp exposed; propodus elongate,
distally tapering; dactyl small, suboval, both arti-
cles folding under merus.

Chelipeds short, stout, merus especially, partly
hairy inside; palms thick, hairy outside: lower
margin convex; immovable finger subtriangular,
broad at base, a small tooth on gripping edge near
tip; dactyl with small basal tooth, remainder of
edge finely and irregularly denticulate. Walking
legs with edges more or less pubescent, second and
third pairs with line of long hairs applied to
posterior surface of carpus and propodus; first leg
thick, merus not reaching laterally beyond carpus
of cheliped; second and third leg about equal;
fourth small, not exceeding merus of third; dac-
tyls of second and third legs longer and more
slender than of first and fourth.

208

FISH AND WILDLIFE SERVICE

Male abdomen with sides gradually convergent,
seventh segment not more than 1.5 times as long
as wide; female abdomen with sides of triangular
portion straight.

Measurements. — Carapace: female, length, 1.6
mm., width, 3.1 mm.; male, length, 2 mm., width,
3.5 mm.

Habitat. — Approximately 3 or 4 to 40 fathoms.

Type locality. — Off Cape Catoche, Yucatan,
[Mexico] ; Albatross station 2362.

Known range. — Off Charleston, S.C. ; south of
Tortugas, Fla.; Puerto Rico; and type locality.

Remarks. — Ovigerous females have been taken
in Florida in August. The ovigerous specimen
taken in Puerto Rico (no date) was found among
ventral spines of a rose sea urchin (J. A. Rivero,
U.S. National Museum).

Genus Dissodactylus Smith, 1870

Rathbun, 1918b, p. 114. — Hemming, 1958b, p. 31.

Dissodactylus mellitae Rathbun
Figure 192

Echinophilis mellitae Rathbun, 1900a, p. 590.

Dissodactylus mellitae: Rathbun, 1918b, p. 117, text-fig. 66,
pi. 28, figs. 7-8 (rev.).— Hay and Shore, 1918, p. 444, pi. 36,
fig. 1.

Recognition characters. — Minute. Carapace
about one-fourth wider than long, slightly wider
at lateral angles than posteriorly, dorsal surface
convex, smooth, and polished except anterior por-
tions slightly pubescent. Edge of front concave,
fringed with short hairs. Anterolateral borders
arcuate, with a fine raised rim curving inward on
carapace at lateral angles and continuing medio-
posteriorly for some distance; posterior margin
sinuous. Orbits opening medially, eyes small.

Figure 192. — Dissodactylus mellitae Rathbun.
dorsal view, 2 mm. indicated.

Animal in

Outer maxilliped with fused, spatulate merus and
ischium; outer edge of carpus arcuate; propodus
quadrate.

Chelipeds short and stout; hand longer than
other articles combined, cylindrical, upper and
outer faces bearing a few impressed, short, oblique
lines with short appressed hairs extending dis-
tally; fingers considerably shorter than palm,
bent inward and curved, opposable margins with
tufts of short bristles ; carpus with a distal fringe
of short hairs and an impressed line similar to
those on chelae; merus short and stout, lower sur-
face with oblique lines. First, second, and third
walking legs stout, margins fringed with short
hairs, dactyls deeply bifid; fourth walking legs
with sty li form dactyls, fringed with long hairs on
margins.

Abdomen of male with first and second, and
third to fifth segments partially fused, margins
convex; telson subtriangular with convex sides.
Abdomen of female with first segment linear, sec-
ond to fourth fused; telson broadly triangular,
half as wide as sixth segment, sides sinuous.

Measurements. — Carapace: male, length, 2.9
mm., width, 3.5 mm. ; ovigerous female, length,
3.3 mm., width, 4.5 mm.

Color. — Light, with scanty dark mottlings
which persist in alcohol and are then of purplish
color (Rathbun, 1018b).

Habitat. — This species clings to the outside of
the keyhole urchin Mellita quinquesperforata and
the sand dollars E china rachnius parma and En-
cope michelini. The crabs are easily overlooked
because as the sand dollars are lifted from the
water, the small crabs may move about and drop
off. Shallow water to 11.5 fathoms.

Type locality. — Pensacola, Fla., on Mellita
quinquesperfo rata.

Known range. — Western part of Vineyard
Sound, Mass., to Charleston, S.C. ; western Flor-
ida.

Remarks. — Hyman (1924a) described the first
zoeal stage of this crab, comparing it to the zoea
of Pinnotheres maculatus, and reported it as com-
mon in plankton tows in the Beaufort, N.C., area
in summer. Ovigerous females occur there during
the same period, and are reported front Narragan-
sett Bay in August (Rathbun, 1918b), and in
Florida from July to October (Wass, 1955, in
part).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

209

Subfamily Pinnothereliinae

( Jarapace transverse, usually broadly so. Ischium
of external maxilliped usually distinct from
merus, though smaller and sometimes imperfectly
united with it. Merus longitudinal or somewhat
oblique; palp of good size, sometimes as large as
merus-ischium (Rathbun, 1918b).

Genus Pinnixa White, 1846

Rathbun, 1918b, p. 128. — Hemming, 1958b, p. 35.

KEY TO SPECIES IN THE CAROLINAS

a. Posterior part of carapace with conspicuous, sharp,
transverse ridge extending uninterruptedly from side

to side cristata (p. 210).

aa. Posterior part of carapace without ridge, or with
ridge on cardiac region only.
b. Chela with immovable finger bent downward.

c. Propodus of third walking leg less than twice as

long as wide chaetopterana (p. 210).

cc. Propodus of third walking leg slender, twice or

more than twice as long as wide sayana (p. 212).

bb. Chela with immovable finger straight or nearly so,
not bent downward.

c. No cardiac ridge present retincns (p. 212).

cc. With cardiac ridge present.

d. Merus of third walking leg with posterior sur-
face not deeply cupped out cylindrica ( p. 213) .

dd. Merus of third walking leg with posterior sur-
face deeply cupped out lunzi (p. 214).

Pinnixa cristata Rathbun

Figure 193

Pinnixa cristata Rathbun, 1900a, p. 589. — 1918b, p. 134, text-
fig. 78, pi. 29, figs. 8-9 (rev.).— Hay and Shore, 1918, p. 446,
pi. 36, fig. 5.

Recognition characters. — Carapace short, sur-
face punctate, wrinkled, and microscopically
granulate, slightly pubescent at extreme outer
corners; a high, sharp, almost straight ridge
extending without a break entirely across cara-

L93. -Pinnitta cristata Rathbun. Male in dorsal
view, legs of left side not shown, 2 mm. indicated.

pace somewhat in front of posterior border; a
deep furrow behind gastric region. Anterolateral
margin with a raised crest stopping short of hepa-
tic region ; posterior margin wide, concave. Front
deflexed, not advanced. Orbit no wider than half
of front.

Chelipeds rather stout ; palm oblong with upper
and lower margins convex, surface covered with
reticulate pattern of fine granulations; immovable
finger short, deflexed, gripping edge with a trun-
cate subbasal tooth, another small tooth distally
forming a truncate tip ; dactyl long, gaping, with
inner margin bent in a curved right, angle. Walk-
ing legs somewhat longer than in related species,
sparsely hairy along margins only, third walking
leg strongest ; dactyls slender, slightly curved on
first three, straight on last walking leg.

Measurements. — Carapace : female, length, 4
mm.; width, 11 mm.

Type locality. — Beaufort, N.C.

Known range. — Beaufort, N.C, to Edisto Is-
land, S.C. ; Grand Isle, La., to Long Lake, Black-
jack Peninsula, Aransas County, Tex. (Hedg-
peth, 1950, and U.S. National Museum records).

Remarks. — The species has been taken from
sandy beaches by digging or sifting in North
Carolina and South Carolina, and Louisiana, and
from the mouth of Galeichthys felis in Louisiana.

Pinnixa chaetopterana Stimpson

Figure 194

Pinnixa chaetopterana Stimpson, 1860a, p. 235. — Rathbun,
1918b, p. 151, text-figs. 93-94, pi. 33, figs. 3-6 (rev.). — Hay and
Shore, 1918, p. 445, pi. 36, fig. 4.

Recognition characters. — Carapace transversely
oval, somewhat more than twice as wide as long,
more swollen in female than in male, surface un-
even, sides densely pubescent. Regions well de-
fined by pubescent grooves; cardiac region with
an acute transverse crest broadly interrupted in
middle forming two dentiform prominences, more
conspicuous in male than in female; subbranchial
region advanced, forming a prominent shoulder
with granulated edge. Posterior margin concave.
Front narrow, with a deep median groove.

Chelipeds stout, smooth, pubescent. Hand in
male with distal palmar edge perpendicular; im-
movable finger short, deflected, truncate at tip,
with a prominent rounded tooth on cutting edge;
dactyl strongly curved, almost vertical, forming

210

FISH AND WILDLIFE SERVICE

Figure 15>4. — Pinnixa chaetopterana Stinipson. A, male
in dorsal view ; B, chela of male in frontal view ; C,
chela of female in frontal view ; 5 mm. indicated.

oval gape when closed with tips of fingers meet-
ing. Hand of female relatively smaller; immova-
ble finger with tooth somewhat beyond middle
followed by an irregularly dentate, raised, cutting
edge terminating in a blunt tip; dactyl with a
small basal tooth, longer than in male, fingers
agape proximal to cutting portion when closed
with tips crossing each other. First and second
pairs of walking legs slender, propodi with distal
V-shaped row of spinules on lower border ; dactyls
with one or more short rows of spinules. Third
pair longer and much stouter, conspicuously pu-
bescent, and with inferoposterior margins of is-
chium, merus, and propodus dentate; fourth pair
like third but smaller, with minute spinules on
dactyls.

Male abdomen with sixth segment slightly con-
stricted laterally, at middle; telson semicircular.

Measurements. — Carapace : male, length, 6 mm.,
width, 14 mm.; female, length, 6 mm., width,
11 mm.

Variations. — Wass (1955) pointed out, that two
forms of this species occur on the northern Gulf
of Mexico coast, a larger and smaller form.

Color. — Nearly white, but usually much ob-
scured by brown or blackish hairs and by dirt
collected in them; eggs bluish (various authors).

Habitat. — The large form of this crab lives com-
mensally with the worms Chaetopterus varioped-
atus and Amphitrite ornata, and is seldom found
outside their tubes. The small form lives in the
upper portion of Callianassa burrows on the

northern Gulf coast (Wass, 1955). Intertidal to
8.5 fathoms.

Type locality. — Charleston Harbor, S.C., on
muddy or clayey shores in tubes of Chaetopterus
variopedatus [ = perga/nentaceus].

Known range.- — Wellfleet, Mass., to South Caro-
lina; Punta Rassa, Fla., to Galveston, Tex.; Rio
de Janeiro, and Villa Bella, Sao Sebastiao, Brazil.

Remarks. — Ovigerous females have been re-
ported from Beaufort, N.C., between April (Gray,
1961) and late October (Enders, 1905), from
Florida in October (Wass, 1955) and February
(Gray, 1961), and from southern Massachusetts
in July and August (Pearse, 1913; Rathbun,
1918b). Otherwise they are known from South
Carolina in February. Faxon (1879) and Hyman
(1924a) described the first zoeal stage.

Some habits of this crab were observed by
Pearse (1913) at Woods Hole, Mass. The species
is strongly thigmotactic. Crabs placed on sand
in an aquarium usually buried themselves, but
soon explored the surface and entered and re-
mained in glass tubes left lying on the sand. In
experiments, crabs found a buried, artificial "Cha-
etopterus tube" by accident. Adult crabs could
enter or leave this tube. The crabs moved either
forward or sideways on sand. The third walking
leg was the chief locomotor organ, but in tubes the
crabs braced themselves with all the legs.

Crabs placed in standing water in an artificial
worm tube were able to exist for 8 days before
leaving the tube for better aerated water. The
crabs' respiratory currents were feeble and incon-
stant in direction and force. Crabs were usually
fouled with encrusting organisms and they took
no trouble to clean their bodies except for mouth
parts, eyes, and antennae. They fed by extending
the fringed external maxillipeds and sweeping
them toward the mouth, filtering small particles
from the water, then cleaning the fringe with
other mouth parts.

Gray (1961, see also account for Polyonyx gib-
besi) described Pinnixa chaetopterana. as primar-
ily a mud crab and a facultative commensal of
Chaetopterus. He found that the crabs readily
enter and leave the tubes of the host, and if di-
ameter of the parchment chimney of the worm
tube is too small, the crab bites a hole at the base
of the chimney to make an entrance or exit.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

211

Pinnixa sayana Stimpson

Figure 195

Pinnixa sal/ana Stimpson, 1860a, p. 236 ; Rathbun, 1918b, p.
15,6, text-fig. 98, pi. 34, figs. 2-4 (rev.). — Hay and Shore, 1918,
p. 446, pi. 36, fig. 3.

Recognition characters. — Carapace smooth, pol-
ished, lightly pubescent on sides, depressed at
middle, a low, ill-defined, transverse ridge parallel
with and close to posterior margin extending
about one-third width of carapace. Anterolateral
slope with similar ridge, lateral two-thirds of
crest beaded. Front deeply grooved above.

Chelipeds with hands stout, compressed, hardly
twice as long as broad; immovable finger very
short, with truncate basal tooth; dactyl strongly
curved. Walking legs long and slender, smooth;
first walking leg reaching to propodus of second ;
second and third leg same length ; fourth reaching
beyond middle of carpus of third ; merus of third
leg approximately 3.5 times as long as wTide, lower
margin, and that of propodus, minutely denticu-
late; dactyls of first two legs slightly curved, of
third straight, posterior edge, of last dactyl
slightly convex.

Measurements. — Carapace : male, length, 5 mm.,
width, 10 mm.; female, length, 4 mm., width,
7 mm.

Variations. — Females differ from males in that
the cardiac ridge is lower and less sharp, the fin-
gers do not gape, the immovable finger is longer
and less bent, and the dactyl on the chela is more
oblique.

Color. — Almost white, but lightly stained with
brown.

Figure 195. — Pinnixa sayana Stimpson. Male in dorsal
view, legs of left side uot shown, 1 mm. Indicated.

Habitat. — The species has been found free in
the water, has been dug out of mud, and is said
to be found in the tubes of Arenicola cristata;
shore to 26 fathoms.

Type locality. — Mouth of Beaufort Harbor,
N.C., 6 fathoms, sandy mud.

Known range. — Vineyard Sound, Mass., to
Beaufort, N.C. ; Sarasota Bay, Fla., to Grand Isle,
La.

Remarks. — Ovigerous females have been re-
ported in August from Narragansett Bay, R.I.
(Rathbun, 1918b), and are known in September
from Louisiana. The last zoeal stage of a Pinnixa,
commonly found off the New England coast and
described by Faxon (1879), was tentatively re-
ferred to this species by Smith (1880a). Both
Faxon and Smith found the first crab stage to fol-
low immediately the last zoeal stage. These stages
in development of P. sayana were summarized and
illustrated by Hyman (1924a).

Pinnixa retinens Rathbun

Figure 196

Pinnixa retinens Rathbun, 1918b, p. 139. text-figs. 83-84,
pl. 41, figs. 1-2.

Recognition characters. — Carapace nearly twice
as wide as long, almost flat, except sloping down-
ward toward margins; regions indicated. Lateral
margin marked by sharp, granulate ridge reach-
ing to subhepatic sulcus, no cardiac ridge; postef-
rior margin preceded by a subparallel groove.
Outer maxilliped with obliquely spatuliform
dactyl attached to middle of inner margin of
propodus.

Chelipeds small, approximately as long as first
leg; hand with lower margin straight, suboblong,
marginate below; fingers slender, subequal, not
gaping; dactyl with tooth at proximal third of
gripping edge. First and second walking legs
similar; second a little longer, dactyls slightly
curved, long, pointed. Third walking leg stout,
exceeding second by length of dactyl and half of
propodus; lower edge of ischium, merus, and pro-
podus armed with stout spinules; posterodistal
end of ischium prolonged in a stout, curved spine
with point directed upward and backward; dactyl
more curved than in first and second legs, pointed.
Last leg extending to distal end of third merus;
dactyl stout, nearly straight, tip curved slightly
upward.

212

FISH AND WILDLIFE SERVICE

Figure 196. — Pinnixa rctinens Rathbun. A, female in dor-
sal view, legs of left side not shown, 5 mm. indicated ;
B, male abdomen ; C, male third walking leg, lower
side ; D, male left chela ; B-D, holotype approximately
X 9 (after Rathbun, 1918b).

Abdomen constricted at base of second segment,
widest between second and third, and tapering to
base of telson; telson wider than long; anterior
and posterior margins of sternal segments granu-
late.

Measurements. — Carapace : male, length, 4 mm.,
width, 7 mm.; ovigerous female, length, 6 mm.,
width, 12 mm.

Habitat. — An ovigerous female was taken from
the burrow of Upogebia affinis at Alligator Har-
bor, Fla., in June (Wass, 1955). Small specimens
have recently been taken from mud bottom in
Chesapeake Bay (Wass, personal communica-
tion). Near low-tide mark to 20 fathoms.

Type locality. — Chesapeake Bay, off Poplar
Island, Md., 20 fathoms, soft bottom.

Known range. — Chesapeake Bay; Alligator
Harbor, Fla.; Aransas area of Texas coast (U.S.
National Museum records).

Remarks. — Though this species has never been
reported in the Carolinas, its occurrence in the
above localities would indicate that it probably
ranges at least between them.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 O— 65 15

Pinnixa cylindrica (Say)

FMgure 197

Pinnotheres cylindricum Say, 1818, p. 452.

Pinnixa cylindrica: Rathbun, 1918b, p. 159, text-fig. 99, pi. 35,
figs. 5, 8 (rev.).— Hay and Shore, 1918, p. 44)6, pi. 36, fig. 2.

Recognition characters. — Carapace smooth,
polished, punctate, punctations small and scarce
in middle third, large and more numerous else-
where; pubescent at extreme outer corners; de-
pressed in middle; anterior cardiac region sepa-
rated from gastric and branchial regions by a
groove. Anterolateral portions with a sharp
granulate crest not reaching cervical suture ; mid-
dle of cardiac region crossed by a transverse
(sometimes inconspicuous) ridge; posterior bor-
der short, somewhat concave. Front not promi-
nent, bilobed, with submarginal groove.

Chelipeds moderately stout, smooth, punctate;
hands suboval, approximately 1.5 times as long as
wide; fingers horizontal, subequal in length, tips
strongly hooked, overlapping when closed, leav-
ing a gape; immovable finger with tooth near tip;
dactyl with a tooth near middle; a finely milled
crest running from tip of immovable finger back-
ward and upward approximately two-fifths length
of palm on outer surface. First walking leg slen-
der, reaching to propodus of second; second
stouter, reaching to middle of dactyl of third;
third leg stoutest, merus 1.6 times as long as wide,
distally narrowed, upper and lower margins finely
granulate; fourth short; dactyls nearly straight,
that of fourth leg convex posteriorly, slightly con-
cave anteriorly.

Abdomen of male with sixth segment con-
stricted laterally, constriction narrower than tel-
son.

Measurements. — Carapace : male, length, 7 mm.,
width, 14 mm. ; female, length, 10 mm., width, 20
mm. (McDermott, 1962).

Figure 197. — Pinnixa cylindrica (Say). Female in dorsal
view, legs of left side not shown, 5 mm. indicated.

213

Color— Yellowish gray, light to dark brown,
or sometimes grayish, and mottled with dark gray
and/or white. Rhythmic chromatophore changes
as well as genetic differences may control observed
variations (McDermott, 1962).

Habitat. — The species lives in burrows of
Arenicola cristata Stimpson (Wass, 1955; Mc-
Dermott, 1962), and possibly with other large
annelids ; shallow water to 20 fathoms.

Type locality. — Jekyll Island, Ga.

Known range. — North Falmouth, Mass., to Alli-
gator Harbor, Fla.

Remarks. — McDermott (1962) summarized
existing knowledge of the habits of this species
and added numerous ecological observations. He
reported the crab for the first time from New
Jersey, finding it associated with 76 percent of the
lugworms collected during summer. Crabs and
worms were collected by manual digging. With
one exception, single crabs were found on worms.

Of 18 female crabs found in July, 16 were ovig-
erous. One captive female produced eggs on July
7 and liberated zoeae "around" August 5. Crabs
which liberated zoeae when collected produced
new sponges of eggs which were in late stages of
development approximately 30 days later. Mc-
Dermott judged that this species produces at least
two egg masses in a breeding season. Molting be-
tween broods did not occur in the laboratory.

Associates of P. cylindrica were found to be
Zoothammiwm sp., attached Crepidula convexa
Say, and colonies of Triticella elongata (Osburn).

Pinnixa lunzi Glassell

Figures 198-199
Pinnixa lunzi Glassell, 1937, p. 3, figs. 1-8.

Recognition characters. — Carapace slightly
more than twice as wide as long, punctate, regions
indicated, borders flanged, with a shoulder
formed near wide lateral angle. Gastric and car-
diac regions separated by a depression connecting
with a deeper depression on each side of these re-
gions; a prominent cardiac ridge extending trans-
versely almost across carapace with an abrupt
slope from crest of ridge to posterior border.
Front prominent, bilobed, truncate, upturned over
antennules.

Chelipeds stout; hands of male shorter and
stouter than in female, appearing disproportion-
ately small in female; palm with margins sub-
parallel in female, widest at base of dactyl in
n uile; in both sexes fingers gaping; immovable
finger horizontal, armed with row of small teeth,
distal tooth largest ; dactyl stout, curved, armed
with median lobe. Walking legs stout. First two
lightly crested with setae on merus; carpus crested
with a sharp beaded rim; propodus armed with a
row of fine, sharp, brown spinules; dactyls con-
torted, sharp pointed, fluted, with rows of small,

Figure 198. — Pinnixa lunzi GlasseU. Male holotype in
dorsal view, 7 mm. indicated (after Glassell, 1937).

Figure 199. — Pinni.m lunzi Glassell. A, right chela of
male ; B, right chela of female. 3 mm. indicated ; C. left
third walking leg of female, 4 mm. indicated; D, ab-
domen of female, 6 mm. indicated ; E, abdomen of male,
3 mm. indicated (after Glassell, 1937).

214

FISH AND WILDLIFE SERVICE

sharp, forward pointing spinules on crests. Third
leg large; merns with two separated, upper, cren-
ulated margins, lower border tuberculate, poste-
rior surface with a deep, pubescent concavity,
smooth within; ischium at lower distal end ex-
tending well past base of merus and with meral
concavity continued on posterior face, lower bor-
der tuberculate; carpus and propodus together
equal in length to upper length of merus; dactyl
stout, nearly straight, without minute spinules.
Fourth leg similar to third but smaller, merus
with lower border tuberculate, dactyl slightly up-
turned at tip.

Male abdomen with telson semioval, sides not
wider than concave sided sixth segment ; third,
fourth, and fifth segments partially fused.

Measurements. — Carapace : male, length, 9 mm.,
width, 21 mm.; female, length, 9 mm., width,
21 mm.

Color. — In alcohol, a muddy bluish brown ; legs,
abdomen, and chelipeds ivory.

Type locality. — Isle of Palms (about 15 miles
northeast of Charleston, S.C.), washed on beach,
under drift material.

Remarks. — The above account is taken chiefly
from Glassell (1937). The types are the only
known specimens and the host and habitat are un-
known.

Family Palicidae

Carapace broadly transverse, subquadrilateral.
Anterolateral margins dentate. Frontoorbital
width great, front dentate. Orbits and eyes large.
Buccal cavity quadrate, outer maxillipeds not
covering it ; ischium of third maxillipeds strongly
produced forward on inner side; merus small,
subtriangular, with a notch on inner distal side
for articulation of palp. Afferent channels to
branchiae opening at bases of chelipeds; efferent
channels at anteroexternal angles of buccal cavity.

Chelipeds of moderate size, often unequal in
male, usually tuberculate or granulate. Next three
pairs of legs long, slender, and rough; last pair
either very short and slender, subdorsal, smooth,
or similar in position and ornamentation to other
legs, and near size of first walking leg. Abdomen
of male much narrower than sternum (Eathbun,
1918b).

Genus Palicus Phillipi, 1838

Rathbun, 1918b, p. 183; Holthuis and Gottleib, 1958, p. 104.

KEY TO SPECIES IN THE CAROLINAS

a. Merus of second and third walking legs with an obtuse
lobe at superodistal angle ; frontal notch shallow, form-
ing nearly a right angle at base alternatus (p. 215).

aa. Merus of second and third walking legs with a promi-
nent, sharp pointed lobe at superodistal angle ; frontal
notch deeper than wide faxoni (p. 216).

Palicus alternatus Rathbun

Figure 200

Palicus alternatus Rathbun, 1897a, p. 95.

Cymopolia alternata: Rathbun, 1918b. p. 188, text-fig. 117,
pis. 42-43 (rev.).

Recognition characters. ■ — Carapace broader
than long, somewhat depressed, elevations covered
with small tubercles composed of single or a few
granules. Front broadly triangular, notched at
middle, with four lobes or teeth, outer teeth less
advanced than inner and broadly rounded. Eyes
large; orbits deep, with upper border cut into
teeth; middle tooth broad, obliquely truncate,
bounded on each side by a V-shaped fissure ; next
tooth separated from outer tooth by a shallow
sinus; outer tooth directed forward or a little
outward, tip curved inward. First two anterolat-
eral teeth dentiform with rounded tips, separated

Figure 200. — Palicus alternatus Rathbun. Animal in
dorsal view, legs of left side not shown, 5 mm.
indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

215

by small V-shaped sinuses; third tooth rudimen-
tary or in form of a small tubercle. Suborbital
margin oblique, with two clefts; outer lobe nearly
straight ; inner lobe divided into two parts with
inner angle produced in an acute tooth beyond
triangular, pterygostomian lobe. Posterior mar-
gin bordered above by a thin, sinuous, elevated
ridge broken into a variable number of unequal
transverse tubercles with usually some granules
interspersed.

Chelipeds of male occurring in two forms. In
one form, chelipeds very unequal ; on right side
large and heavy, on left, slender and weak, both
tuberculate and pubescent ; carpus with an outer,
laminated, lobed crest; hand surmounted by a
similar double crest. Right hand very thick, width
at distal end often equaling one-half length of
carapace; immovable finger short, wide; dactyl
strongly bent down, overlapping opposed finger
and leaving a narrow gape. Left hand somewhat
over one-third width of right, fingers long and
narrow. In second, weaker form males, right hand
about twice depth of left ; fingers long and slender.
Females with chelipeds more nearly equal.

Second pair of walking legs longer than others.
First walking legs reaching middle of propodus
of second, with posterior margin of propodus and
proximal half of dactyl hairy in male; third walk-
ing leg reaching middle of dactyl of second,
fourth leg slender, much shorter than third. Meri
rough with squamous tubercles ; with a single lon-
gitudinal groove on anterior surface, two on upper
surface; first three meri with a superodistal lobe,
subtriangular on first, subrectangular in second
and third, lobe exceeding article in first, equal to
article in second, not reaching end of article in
third. Carpus with a rounded, anterior proximal
lobe ; anterior subdistal lobe low and rounded on
first leg, triangular on second and third legs. Pro-
podus with anterior margin convex, posterior mar-
gin straight.

Abdominal appendages of first form of male
stout and twisted, tip bilobed, inner lobe thinner
and longer than outer; second form of male with
appendages weaker, not twisted, and tip less
spreading.

Measurements. — Carapace: male, 7 mm., width,
8 mm.; female, length, 8 mm., width, 9 mm.

Variations. — This species shows great varia-
tion in structure. In some individuals the cara-

pace is wider behind in proportion to its length
than in typical individuals, and the sides are less
parallel. There is no consistency in relative size
of the anterolateral teeth, for in some the first
are largest and all teeth point forward, but in
others the second teeth are largest and point
slightly outward. In some individuals the antero-
distal tooth on the merus of the second and third
legs is more produced than in typical specimens,
and there is variation in the length-width propor-
tions of the propodus of the second leg. Details
of lobulation on the front and lower margin of the
eye are also subject to variation.

Habitat. — The species has been taken from a
variety of fine and coarse bottoms (Rathbun,
1918b) ; 4 to 60 fathoms.

Type locality.— Lat. 29°11'30" N., long. 85°29'
00" W., 26 fathoms (south of Cape San Bias,
Fla.).

Known range. — Cape Hatteras, N.C. ; Gulf of
Mexico along west coast of Florida from Cape
San Bias to Key West.

Remarks. — Ovigerous females have been re-
ported in Florida from January to August, and
from North Carolina in October (Rathbun, 1918b,
and U.S. National Museum records).

Palicus faxoni Rathbun

Figure 201

Palicus faxoni Rathbun, 1897a. p. 96.

Cymopolia faxoni: Rathbun, 1918b, p. 194, text-fig. 120, pi. 45,
figs. 2-3 (rev.).

Recognition characters. — Carapace broader
than long, sides converging anteriorly; adult fe-
male quite convex, surface hairy, and with numer-
ous tubercles and granules. Front broadly tri-
angular; four frontal lobes well marked, outer
pair not much wider than inner, median emar-
gination deeper than wide with end often rounded,
lateral emarginations shallow. Eyes large; orbits
deep, with upper border cut into teeth by V-
shaped sinuses, middle and outer teeth triangular,
subacute, middle one equilateral, outer one narrow
and separated from outer orbital tooth by a shal-
lower sinus; outer tooth directed forward, tip
oblique, its lateral margin nearly straight. Lateral
border with two similar, sharp-pointed teeth, sec-
ond one smaller, outer borders convex, inner con-
cave. Lower margin of orbit oblique, bilobed;
inner lobe in advance of outer, divided in two,
outer portion rounded, inner portion a small acute

216

FISH AND WILDLIFE SERVICE

Figure 201. — Palicus faxoni (Rathbun). Male in dorsal
view, legs of left side not shown ; cheliped, second and
third walking legs detached ; first and fourth walking
lags from female in Rathbun (1918b) ; 5 mm. indicated.

tooth somewhat obscured by ventrally bent ptery-
gostomian lobe, sharp pointed at tip; outer lobe
slightly convex. Posterior margin preceded by a
tuberculate ridge.

Chelipeds in both sexes somewhat unequal, right
hand approximately twice as wide as left. Walk-
ing legs short and broad ; first three meral articles
with a large, flat, acute distal spine, posterior dis-
tal tooth of merits sharp; carpal lobes prominent,
distal one of second and third legs acute; pro-
podus of second and third legs widening distally,
dactyls wide, posterior margin sinuous.

Measurements. — Carapace: male, length, 10
mm., width, 10 mm.; female, length, 10 mm.,
width, 11 mm.

Habitat. — Thirty-two to 51 fathoms.

Type locality. — Off Cape Hatteras, N.C., 49
fathoms.

Known range. — Type locality ; off Jacksonville,
Fla. ; off Yucatan, Mexico; off Cabo Frio, Rio de
Janeiro, Brazil ( ?).

Family Grapsidae

Front quite wide; carapace usually quadrilat-
eral, with lateral borders either straight or
slightly arched, and orbits at or near anterolateral
angles. Buccal cavern square; generally a gap,

often large and rhomboidal, between external
maxillipeds. Male openings sternal. Palp of ex-
ternal maxillipeds articulating either at antero-
external angle or at middle of anterior border of
merus, exognath either slender or broad. Inter-
antennular septum broad. Division of orbit into
two fossae accented (Eathbun, 1918b).

KEY TO SUBFAMILIES, GENERA, AND
SOME SPECIES IN THE CAROLINAS

a. Antennules folding beneath front of carapace in usual
way.

b. Third maxillipeds without a pubescent oblique ridge.
c. Lower border of orbit running downward toward
buccal cavern ( Subfamily Grapsinae).
d. Carapace decidedly broader than long.

Pachygrapsus transversus (p. 217).
dd. Carapace about as long as broad ; legs strongly

fringed with hairs Planes minutus (p. 218).

cc. Lower border of orbit not running downward
toward buccal cavern, but supplemented by remote
suborbital crest in line with anterior border of
epistome (Subfamily Varuninae)

Euchirograpsus americanus (p. 220).

bb. Third maxillipeds with an oblique pubescent ridge

crossing ischium and merus (Subfamily Sesarminae)

Sesarma (p. 221).
aa. Antennules visible dorsally in deep clefts in front of
carapace (Subfamily Plagusiinae).
b. Carapace broader than long

Plagusia depressa (p. 223).
bb. Carapace longer than broad

Pcrcnon gibbesi (p. 224).

Subfamily Grapsinae

Front usually strongly deflexed. Lower border
of orbit running downward toward buccal cavern.
Antennal flagellum very short. External maxilli-
peds usually separated by a wide rhomboidal gap,
not traversed by an oblique hairy crest; palp
articulating at or near anteroexternal angle of
merus ; exognath narrow and exposed throughout.
Male abdomen filling all space between last pair
of legs (Eathbun, 1918b).

Genus Pachygrapsus Eandall, 1840

Rathbun, 1918b, p. 240.

Pachygrapsus transversus (Gibbes). Mottled shore crab

Figure 202.

Orapsus transversus Gibbes, 1850, p. 181.

Pachygrapsus transversus: Rathbun, 1918b, p. 244, pi. 61,
figs. 2-3 (rev.).— Hay and Shore, 1918, p. 447. pi. 36, fig. 9.

Recognition characters. — Small species. Cara-
pace rectangular, about one-fourth broader than

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

217

Figure 202. — Pachygrapsus transversus (Gibbes). Ani-
mal in dorsal view, legs of left side not shown, 5 mm.
indicated.

long, depressed, polished, with fine transverse
plications, except oblique ones on branchial re-
gions. Sides slightly arched, strongly converging
posteriorly, and armed with a well-marked tooth
behind orbital angle. Front slightly more than
half as wide as carapace, edge sinuous and gran-
ulate, upper surface with four low elevations.
Orbits oblique, approximately two-fifths width of
front, lower border denticulate.

Chelipeds equal, much stouter than legs, 1.6
times longer than carapace in male, finely granu-
late; inner edge of merus produced in a laminate,
toothed expansion; meri of all legs and carpus of
cheliped transversely striated; carpus with blunt
internal tooth ; upper surface of palm with a mar-
ginal line, oblique striae on inner and lower side,
an oblique line on outer surface near lower edge ;
fingers narrowly gaping except for large triangu-
lar tooth near middle of immovable finger. Merus
of walking legs with posterodistal angle dentate;
first and fourth walking legs subequal, second and
third pairs longer and subequal, last three arti-
cles bristly and thorny. Female with conspicuous
feathery hairs on carpus and propodus of first
walking legs.

Male abdomen with telson broadly triangular.

Measurements. — Carapace: male, length, 11
nun.; width, 14 mm.

Color. — Variable; ground color almost black,
olive green, yellowish, yellowish brown or dull
gray, covered by irregular mottlings of dark
brown, reddish or dark olive; usually darkest an-

teriorly with transverse ridges edged with green-
ish gray, reddish or dark brown; chelae often
plain or reddish brown, tips light ; walking legs
brown or blackish with gray spots (various
authors).

Habitat. — This species is found among rocks,
on pilings, on roots of mangroves, and on sandy
shores.

Type locality. — Key West, [Fla.].

Known range. — Cape Lookout, N.C., to Monte-
video, Uruguay; Bermuda. Beyond this region
the species has a wide distribution in tropical and
subtropical seas and has been carried to higher
latitudes than it normally inhabits by transport
on ships' bottoms.

Remarks. — At Bermuda, where this crab is
abundant, ovigerous females have been observed
from April to July (Verrill, 1908). Ovigerous
females have been reported from February to
August in various parts of the Caribbean area
(Kathbun, 1918b, in part), and are known from
North Carolina in August and September. Le-
bour (1944) illustrated some of the larval stages
of this species from their occurrence at Bermuda.

Pearse (1932b) reported the protozoan Episty-
lis, and Verrill (1908) the isopod Leidya distorta
in the gill cavities of this crab.

In the past, occurrence of this crab in the Beau-
fort, N.C., area has been irregular and these in-
trusions from more southerly waters may reflect
annual variations in temperature or occasional
transport on vessels. As Verrill (1908) suggested,
the range of this species may have been greatly
extended by commerce in modern times.

Genus Planes Bowdich, 1825

Rathbun. 1918b. p. 253.— Chace, 1951.— Hemming. 1958b, p. 36.

Planes minutus (Linnaeus). Gulf weed crab; turtle crab;
Columbus crab

Figure 203

Cancer minutus Linnaeus, 1758. p. 625.

Planes mhiutus: Hay and Shore. 1918, p. 448. pi. 36. fig. 6.—
Chaee, 1951, p. 81. figs. la. 2 a. d, g. j, k, 1, 3 a-h (rev.). —
Hnltliuis, 1959. p. 240.

lit cognition characters. — Carapace approxi-
mately as wide as long, subquadrate in young.
trapezoidal in medium sized, laterally convex in
old individuals, convex dorsally, smooth, but with
faint oblique lines on outer part of branchial re-
gion. Front approximately half as wide as cara-

218

FISH AND WILDLIFE SERVICE

Figure 203. — Planes minutus (Linnaeus). Male in dorsal
view, approximately X 2 (after Chace, 1951).

pace, decurved, usually slightly emarginate in
middle, edges minutely denticulate or smooth.
Eyes large ; orbits large, lower margin granulate,
tooth at inner angle equilateral, subacute, outer
angle spiniform, behind it a small sinus.

Chelipeds large and heavy ; merus and ischium
with a thin serrate crest along inner margin ter-
minating in two or three spines at distal end of
merus; carpus with a strong blunt spine on inner
face; hands inflated and smooth except for small
sharp granules near lower margin; immovable
finger bent downward, especially in males, dactyl
curved, both with blunt teeth throughout length.
Walking legs long, slender, and flattened ; second
and third legs subequal, fourth legs shortest ; meri
occasionally with an inconspicuous anterior sub-
terminal tooth and a few posterior denticles; last
three articles thorny and with a dense fringe of
hair on anterior edge.

Abdomen of male rather broadly triangular;
telson rather narrowly triangular, approximately
as long as basal width.

Measurements. — Carapace: male, length, 19
mm., width, 19 mm. Length of a large series re-
ported by Chace (1951), 3.7 to 19 mm.

Color. — Extremely variable; irregularly mot-
tled or blotched with light greenish yellow or
pale yellow on a darker olive-green ground color;
or reddish-fawn color, more or less blotched with
dark brown, and usually with a small white spot
on each side or one large white spot on front of
carapace (various authors).

Crozier (1918) observed no color change in a
mahogany-colored P. minutus placed for a day

on a lighter background. Hitchcock (1941) found
three types of chromatophores in P. minutus:
white, black, and yellow. The most prominent
chromatophore is white. Color adaptation to dif-
ferent backgrounds is slow and though the chro-
matophores are responsive to change in back-
ground, extracellular pigment in the hypodermis
and exoskeleton prevents the animal from effect-
ing an immediate change in appearance. Hitch-
cock concluded that the pattern of the individual
crab is probably genetic. Chace (1951) remarked
that in view of these findings, the apparent color
of any individual can be changed only at the time
of molting.

Habitat. — These crabs are more abundant on
Sarga.ssum in the Sargasso Sea than elsewhere,
but throughout their range they depend on flot-
sam, or on floating or swimming organisms to
which they cling (Chace, 1951).

Type locality.— On sargasso and other sub-
marine sea plants on the north side of Jamaica
(Sloane in Holthuis, 1959).

Known range. — Atlantic Ocean south of New-
foundland, west of 50° W. latitude, and exclusive
of the Gulf of Mexico (Chace, 1951) ; Netherlands
coast, North Sea (van den Oord and Holthuis,
1959).

Remark*. — The genus Planes has been thor-
oughly reviewed by Chace (1951), and the, seri-
ous student should consult this paper. Chace in-
cluded remarks on relative growth, stating
that . . .

The carapace length-width relationship remains fairly
constant with a slight tendency toward narrowing, from
the smallest immature specimens examined to a carapace
length of about 11 mm. At this stage the carapace seems
to become somewhat narrower rather abruptly and con-
tinues to become narrower at a slightly more rapid rate
than during the younger stages. A similar, but even more
striking, trend is noticed in the relative shortening of the
walking legs.

Chace conjectured that the specimens larger
than about 11 mm. are found on flotsam and tur-
tles rather than on sargassum, and that the shorter
legs may be more adapted to this existence than
to life on floating weed. It is also possible that
these sizes represent different forms of Planes
with somewhat different habits, but Chace de-
ferred such a designation until a time when more
material is available for study.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

219

Both Hyman (1924b) and Lebour (1944) il-
lustrated some larval stages of Planes minutus.
In the region of the Carolinas, ovigerous females
have been taken virtually throughout the year.

Subfamily Varuninae

Front moderately or little deflexed, sometimes
sublaminar. Branchial region with downward
sloping posterolateral portion set off from rest of
region by a more or less distinctly marked line.
Suborbital crest, supplementing defective lower
border of orbit, rather distant from orbit and usu-
ally running in a line with anterior border of
epistome. Antennal flagellum usually of good
length. External maxillipeds moderately or
slightly gaping, without oblique hairy crest; palp
articulating with middle of anterior border or
near anteroexternal angle of merus; exognath in
American genera rather narrow, sometimes partly
concealed. Male abdomen rarely covering all
space between last pair of legs (Eathbun, 1918b).

Genus Euchirograpsus Milne Edwards, 1853

Rnthbun. 1918b, p. 281 — Hemming, 1958b, p. 81.

Euchirograpsus americanus Milne Edwards

Figure 204

Euohirograpsus americanus Milne Edwards, 1S80, p. 18. — 'Rath-
bun, 1918b, p. 282, text-fig. 144, pi. 74.— Hay and Shore. 1918,
p. 448, pi. 36, fig. 7.— Garth, 1946, p. 511, pi. 85, figs. 5-6.

Recognition characters. — Carapace slightly
broader than long; sides nearly straight and par-
allel, flattened posteriorly, sloping gently down
toward sides and front ; surface covered with
granules and short, soft hair. Front somewhat
produced, lamellate, with a narrow median notch.
Eyes large; orbits large, a small tooth at inner
angle; upper margin oblique, sinuous; outer angle
spiniform, behind it three smaller spines on lateral
margin, middle spine largest; lower margin of
orbit denticulate. Third article of antennae hol-
lowed out on inner side.

Chelipeds stout, 1.5 times as long as carapace;
merus with surface crossed by fine granulated
lines, margins spinulose, a superior subdistal
ie; carpus with inner distal margin spinulose;
hand with three spinulose ridges above, a ridge
near lower edge, and another less distinct through
middle; fingers slender, grooved, pointed, grip-

Figure 204. — Buchirograpsus americanus Milne Edwards.
Animal in dorsal view, walking legs of left side not
shown, 5 mm. indicated.

ping edges with low, irregular teeth fitting to-
gether. Walking legs slender, compressed, hairy;
second pair over twice length of carapace; all
meri crossed by fine granulated lines and with
three subdistal spines, one above, one inner, and
one outer below, first merus spinulose below;
dactyls armed with long spines.

Measurements. — Carapace: female, length, 14
mm.; width, 16 mm.

Color. — Yellowish gray, arranged in marblings
on carapace and in alternately light and dark
bands on legs, or light brown with five or six
bands of red on legs ( various authors) . More de-
tail given by Garth ( 1946 ) .

Habitat. — Seventeen to 278 fathoms.

Type locality. — Barbados, 69 fathoms, Blake
station 278.

Known range. — Off Oregon Inlet, N.C., through
West Indies to Barbados, and through Caribbean
Sea to Monosquillo [Morrosquillo], Colombia;
Galapagos Islands.

Remarks. — This species had rarely been taken
off the Carolinas until recently. Offshore collect-
ing has shown it to be not uncommon, and a
northern, as well as upper bathymetric record,
was established when an ovigerous female was
taken off Oregon Inlet. X.C., at 17 fathoms in
February (Cerame- Vivas, Williams, and Gray,
I'm;:',). Ovigerous females are otherwise known in
Florida from March to September.

220

FISH AND WILDLIFE SERVICE

Subfamily Sesarminae

Front strongly deflexed. Lower border of orbit
commonly running: downward toward angle of
buccal cavern. Side walls of carapace finely re-
ticulated with granules and hairs or hairs only.
External maxillipeds separated by a wide rhom-
boidal gap, an oblique hairy crest traversing them
from a point near anteroexternal angle of ischium
to a point near anterointernal angle of merus;
palp articulating either at summit or near antero-
external angle of merus; exognath slender and
either partly or almost entirely concealed. Male
abdomen either filling or not quite filling all space
between last pair of legs (Rathbun, 1918b).

Genus Sesarma Say, 1817

Rathbun, 1918b, p. 284.

KEY TO SPECIES IN THE CAROLINAS

a. Lateral margin of carapace sinuous ; last three articles
of first three walking legs tomentose ; body strongly
convex above reticulatum (p. 221).

aa. Lateral margin of carapace straight ; walking legs not
tomentose; body nearly flat above c'mercum (p. 222).

Sesarma (Sesarma) reticulatum (Say)

Figure 205

Ocypode reticulatus Say, 1817, p. 73, pi. 4, fig. 6.
Sesarma reticulatum: Rathbun, 1918b, p. 290. pi. 77 (rev.).
Sesarma reticulata: Hay and Shore. 191S. p. 448, pi. 36, fig. 12
(rev.).

Recognition characters. — Carapace about four-
fifths as long as broad, convex, regions distinct,
surface punctate and with scattered clumps of
setae above and in front ; sides concave behind
widest point, convergent at orbital angles. Pos-
terolateral regions obliquely striated and setose;
inferolateral and frontal regions with irregular

Figure 205. — Sesarma (Sesarma) reticulatum (Say).
Animal in dorsal view, 10 mm. indicated.

rows of tubercles bearing short, curved hairs. Dor-
sal portion of carapace overhanging sides; be-
neath projecting shelf a line of cilia. Lower sur-
face of carapace covered with fine net of geniculate
hairs. Front broad, slightly sinuate above basal
articles of antennae. Eyestalks short and stout,
set in deep oval orbits; a deep gap below outer
orbital angle leading into system of grooves open-
ing into a notch at anterolateral angle of buccal
cavern. External maxillipeds separated by a wide
rhomboidal gap largely filled by a hairy fringe,
and obliquely traversed by a conspicuous line of
hairs from point behind anteroexternal angle of
ischium to anterointernal angle of merus.

Chelipeds stout, subequal in male; merus and
carpus lightly rugose; merus with an obtuse sub-
terminal tooth above, both lower margins denticu-
late; carpus with inner angle rounded. Palm al-
most smooth, in male a little higher than
midlength, upper edge with a single granulate
line, inner surface with a short irregular ridge of
tubercles near distal end; dactyl with seven to
nine depressed spinules above on basal two-thirds ;
fingers agape, an enlarged tooth near each end.
Palm of female half again as high as midlength,
fingers slightly agape. Third pair of walking legs
approximately twice as long as carapace, last
three articles densely tomentose.

Measurements. — Carapace: male, length, 23
mm. ; width, 28 mm.

Color. — Carapace, dark olive, nearly black or
purple ; dark plum colored or bluish-black speck-
les crowded on grayish background, grayish color
showing little except on posterior part ; upper
part of chelipeds similarly colored but brighter,
greater part of palm yellowish, tips of fingers
white or yellowish; upper part of legs as cara-
pace; under parts grayish (various authors).

Habitat. — Burrows in muddy salt marshes.

Type locality. — Muddy salt marshes [east coast
of United States] .

Known range. — Woods Hole, Mass., to Calhoun
County, Tex.

Remarks. — Ovigerous females have been re-
ported from Massachusetts in July, and in sum-
mer months farther south on the coast. Crichton
(1960) found 8,000 to 10,000 eggs per egg mass.

Hyman (1924b) described the first zoeal stage
and compared it with S. ckiereum. Recently, Cost-
low and Bookhout (1962a) described the complete

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

221

larval development listing three zoeal stages and
one megalops stage, and compared these to simi-
lar stages they had previously described for S.
cinereum. The authors also concluded that photo-
period has no observable effect on development.

Crichton (1960) studied a colony of S. reticula-
tum in Delaware. With the aid of rubber casts, he
found that the species digs burrows which may
have several openings leading at a gentle slope to
a depth of 3 or 4 inches where a series of more or
less level corridors curve, twist, and often inter-
connect. Each corridor usually leads to a vertical
shaft as much as 30 inches deep and usually filled
with water. Burrows are communal, containing
a male or two and several females. Crichton
found that this species will eat fiddler crabs (the
burrows occasionally intersect) when it can cap-
ture them; however, the usual diet is Spartina,
and swaths often are cut through this marsh grass.
Burrowing action of the crab tills the land, in-
creases erosion, and turns over the cord grass more
rapidly than the annual decay cycle could do it
unaided.

Teal (1959) found this species active on Geor-
gia marshes when the tide was high or the sky
cloudy. "When the marsh was exposed, the crabs
were found in burrows, usually near the top, in
air or water. Respiration rates were higher in
water than in air. Gray (1957) found the gill
area of S. reticulatum to be relatively low as com-
pared with other species living in a similar habitat
(Uca pugnax and minax). He found S. reticula-
twm to be more robust but less active than the close
relative, S. cinereum.

Humes (1941) described a harpacticoid cope-
pod (Canerincola plwmipes) from the gill cham-
bers of this crab.

Sesarma (Holometopus) cinereum (Bosc). Wharf crab:
wood crab; friendly crab; square-backed fiddler

Ficure 206

Orapnu.1 einerru* Rose [isol or 1802], p. 204, pi. 5, fie. 1,
Sesarma cinereum: Rathbun, lfUSh. p. .too, text-flg. 149, pi. 83
(rev.).
Sesarma einerca: Hny and Shore, 1 !»1 8. p. 440, pi. 36, fig. 11.

Recognition rim meters. — Carapace rectangular,
nearly uniform in width throughout ; regions well
M'']: surface nearly smooth, punctate, rough
with squamiform tubercles toward front; supra-
frontal lobes well marked, inner pair widest.
Front 4 times us wide as high, widening helow,

Figure 206. — Sesarma (Holometopus) cinereum (Bosc).
Animal in dorsal view, 5 mm. indicated.

somewhat four-lobed in dorsal view, lower edge
sinuous. Outer orbital angle acute. Lower sur-
face of carapace covered with fine net of genicu-
late hairs.

Chelipeds heavy; merus and carpus covered
with short transverse lines of scabrous granules;
merus with upper edge sharp, inner edge irregu-
larly dentate with a triangular laminar expansion
on distal half; carpus with inner angle rounded.
Palm nearly twice as high as upper length; outer
surface covered with scabrous granules arranged
in parallel lines near upper margin; inner face
coarsely granulate, with short prominent ridge
near distal end; fingers gaping narrowly, largest
tooth at middle of immovable finger. Walking
legs rather narrow, meri with a superior subdistal
spine; third pair of legs over twice as long as
carapace.

Abdomen of male broadly triangular; telson
much narrower than sixth segment.

Measuretnents. — Carapace : male, length, 18
mm., width, 20 mm.; female, length, 20 mm.,
width, 23 mm.

Color. — Brown varying toward olive.

Habitat. — Found actively crawling about on
wharves and stone jetties or resting in shallow
burrows above tidemark along the shores. The
crabs have often been found on vessels along the
coast hiding anywhere out of sight or reach and
coming forth at night to feed.

Type locality. — uLa Caroline.''''

Known range. — Magothy River, Chesapeake
Bay, Md., to British Honduras; West Indies to
Venezuela.

Remarks. — This species is abundant where it
occurs in the Carolinas. Oviirerous females occur

222

FISH AND WILDLIFE SERVICE

from May to November in North Carolina, and
have been found along the Potomac River in Jan-
uary (U.S. National Museum records). Hyman
(1924b) briefly described the first zoeal stage.
Costlow and Bookhout (1960) described 4 zoeal
stages and 1 megalops stage from 1,200 zoeae
reared on Artemia nauplii and Arbacia eggs under
constant conditions of temperature, salinity, and
light. Costlow, Bookhout, and Monroe (I960)
found that optimum salinities exist for each larval
stage, but that development proceeds best in
the 20-26.7 °/oo range (among those tested).
Temperature was found to have more effect on
length of larval development than on mortality,
with higher temperature speeding development.
No "extra stages" were observed. The authors
concluded that salinity is the chief physical factor
confining S. cinereum to estuaries.

Pearse (1929) found that this species can sur-
vive for a considerable period of time in dilutions
of sea water and also that it shows considerable
resistance to desiccation. Oler (1941) maintained
captive specimens from a Maryland tidal river in
a house basement for about a year. The animals
burrowed in mud in an aquarium where the only
moisture provided was tap water. Vegetable mat-
ter was fed at irregular intervals. After several
months, the larger animals ate the smaller ones,
presumably at the time of ecdysis. Duncker
(1934), in Germany, secured three live female S.
cinereum which had been transported by chance in
a cargo of logs from the West Indies. The animals
were kept alive in a glass jar with damp peat and
a container for a source of fresh water. One lived
4 years and 72 days from date of captivity. The
crabs were fed shredded beef or fish and commer-
cial fish food plus Collembola that appeared in the
jar. All eating was done on land. Some regen-
eration of lost appendages occurred, and the long-
est lived specimen molted four times, molting al-
ways taking place in water. To the author's
surprise, eggs were released six times, always in
water, the longest lived female producing five of
these batches. Larvae hatched from all but one
of the egg masses, but survived only a short time.
Duncker concluded that one mating was effective
for 3 years or more. The incubation period was
approximately 30 days. The female ate eggs that
protruded over the edge of the abdomen. The
number of eggs ranged from about 4,700 to 13,400

per sponge. Duncker considered that S. cinereum
acted more like a land animal than a water-
inhabiting animal, each individual having its own
burrow.

Teal (1959) implied the same conclusion, for
in experiments under water this species was rel-
atively inactive, thus holding its oxygen con-
sumption down. There was some experimental
evidence for thermal acclimation of metabolism,
but more evidence for acclimation by selection
of microclimate. Gray (1957) also emphasized
the terrestrial habits of the species, but showed
that its relative gill area is nearly double that of
the similar species Ocypode quadrata.

Subfamily Plagusiinae

Front cut into lobes or teeth by antennular
clefts visible in dorsal view. Lower border of orbit
curving down into line with prominent anterior
border of buccal cavity. External maxillipeds
neither completely closing buccal cavity nor leav-
ing wide rhomboidal gap, not crossed by an
oblique hairy crest ; palp articulating near antero-
external angle of merus, often no flagellum on
exposed exognath. Antennal flagella short. Male
abdomen filling all space between last pair of legs
(Rathbun, 1918b.).

Genus Plagusia Latreille, 1804

Rathbun, 1918b, p. 331.— Monod, 195G. p. 455.

Plagusia depressa (Fabricius)

Figure 207

Cancer depressus Fabricius, 1775, p. 406.

Plagusia depressa: Rathbun, 1918b, p. 332, text-fig. 154, pi. 101
(rev.).— Monod, 1956, p. 455, figs. 614-617 (rev.).

Recognition characters. — Carapace subhexag-
onal, wider than long, depressed, covered with
flattened tubercles margined with short setae.
Regions distinct; front of gastric region with a
series of approximately six, prominent, acute tu-
bercles arranged in an arc. Indefinite front broad,
with a deep median furrow and deep notches for
antennules ; a spinif orm tubercle on each side be-
tween median furrow and antennulary notch.
Orbits deep; outer orbital angle produced into a
strong, curved spine followed on anterolateral
margin by three similar spines of diminishing
size. Epistome prominent beyond anterior border
of carapace and usually cut into five lobes.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

223

Figure 207. — Plagusia depressa (Fabricius). Animal in
dorsal view (after Rathbun, 1933).

Chelipeds of adult male massive, approximately
as long as carapace, in female slender, three-
fourths as long as carapace; chelipeds and legs
rugose dorsally; merus with three small spines
above at distal end; carpus with inner angle
densely dentiform; palm and dactyl with tuber-
cles arranged in longitudinal ribs, outer surface
smooth. Walking legs strong, increasing in size
from first to third, fourth shorter than second;
second and third legs with a dentate crest above
on coxae; meri with subterminal spine on anterior
border; distal three articles with a dense strip of
long hair; dactyls with two rows of strong spines
on concave side.

Measurements. — Carapace : large female, length,
45 mm. ; width, 49 mm.

Color. — Light reddish, dotted with blood red,
tubercles bordered with blackish cilia with ex-
tremity gray; blood-red spots on legs; underside
of body yellowish (Latreille in Rathbun, 1918b).

Habitat. — This species is found among rocks,
on jetties, in tide pools, and is thought to be trans-
ported on ships' hulls.

Type locality.- — "In man mediterraneo.''''

Known range. — Beaufort, N.C. through West
Indies to Pernambuco, Brazil; Bermuda; Azores;
Madeira; West Africa, from Senegal to Gold
Coast.

Genus Percnon Gistl, 1848

Rathbun, 1918b, p. 337. — Hemming, 1958b, p. 35.

Percnon gibbesi (Milne Edwards). Spray crab

ocarpus gibtesi Milne Edwards, 1858, pp. HG and ISO.
Percnon gibbesi: Rathbun, 1918b, p, 337.— Schmltt, 1939, p. 24.

tuition characters. — Carapace thin, disc-
like, longer than wide, covered with small short

bristles except for bare raised patches; dorsal sur-
face with a few low tubercles. Front deeply cut
by antennular furrows; portion between anten-
nules narrow and extended in form of a rostrum,
armed with two erect spines on each side distally
and a row of inconspicuous spinules just within
and parallel to each margin proximally. Eyes
large, reniform. Inner margin of orbit bearing
three spines, two distal spines prominent; middle
of upper orbital border more or less serrate. An-
terolateral border of carapace with four acute
spines counting large spine on outer orbital angle ;
second spine in series with its lateral margin
shorter than that of third spine.

Chelipeds varying in size with age and sex,
small in females but large and unequal in adult
males; merus and carpus armed with spines; palm
nearly smooth, oval, and somewhat compressed,
proximal upper surface with an ill-defined groove
extending one-third length of upper margin,
groove filled with pubescence; fingers short, blunt,
with tips concave on opposed surfaces. Meral arti-
cle of each walking leg with large uniform spines
on anterior margin, upper surface covered with
short bristles similar to carapace ; posterior mar-
gin ending in a distal spine; merus of first two
legs with a second row of spinules parallel with
anterior border, row indistinct on third merus
and absent on fourth.

Measurements. — Carapace: male, length, 30
mm., width, 28 mm.; female, length, 33 mm.,
width, 34 mm. (Garth, 1946).

Color. — Carapace and meral articles of walk-
ing legs brown or mottled above ; usually a median
longitudinal stripe of white or pale blue; legs
banded with reddish, brown, and light pink dis-
tally; eyestalks and chelae orange; ventral side
of body pale blue with legs pale pink (Garth,
1946; Verrill, 1908).

Habitat. — The usual habitat for this species is
the underside of rocks at the low-tide level (Ver-
rill, 1908), or in the surf at knee to hip depth,
where it is extremely difficult to capture because
of its propensity for rapidly keeping to the under-
side of turned objects (Garth, 1946).

Type locality. — Antilles.

Known range.— Fort Macon, N.C; southern

224

FISH AND WILDLIFE SERVICE

Florida and Bahamas to Brazil; Bermuda;
Azores to Cape of Good Hope; Cape San Lucas,
Lower California, to Chile ; Galapagos Islands.

Remarks. — Two immature females found on the
Fort Macon, N.C., jetty in August 1963, by R. A.
Heard, are referred to this species on the basis of
characters given by Schmitt (1939) in his key to
species of the genus Percnon. It is impossible to
refer the descriptions of Rathbun (1918b) and
Verrill (1908) to this species or planissimum with
certainty, and the figures given by them also are
not adequate for this purpose ; but on the basis of
a Bermuda specimen collected in 1962, Verrill's
material was probably P. gibbesi.

Failure to record this species from North Caro-
lina prior to this time is probably because there
are few suitable habitats along this coast. There
are few natural rocks on the North Carolina coast.

Family Ocypodidae

Palp of external maxillipeds coarse, articulat-
ing at or near anteroexternal angle of merus;
exognath generally slender and often somewhat
concealed. Front usually of moderate width, and
often a somewhat deflexed narrow lobe. Orbits
occupying entire anterior border of carapace out-
side front, and with their outer wall often defec-
tive. Buccal cavity usually large and somewhat
narrower in front than behind, external maxil-
lipeds often, but not always, completely closing it.
Abdomen of male narrow. Male openings sternal
(Rathbun, 1918b).

Genus Ocypode Weber, 1795

Rathbun, 1918b, p. 366 (described).— Monod, 1956. p. 390
(synonomy).

Ocypode quadrata (Fabricius). Ghost crab; sand crab

Figure 208

Cancer quadratus Fabricius, 1787, p. 315.

Ocypode albicans: Rathbun, 1918b, p. 367, pis. 127-128
(rev.). — Hay and Shore, 1918, p. 450, pi. 37, fig. 1.
Ocypode quadrata: Holthuis, 1959, p. 259.

Recognition characters. — Carapace quadrilat-
eral, convex above from front to back, sides nearly
vertical ; dorsal region finely granulate on middle
and posterior portions, coarsely granulate toward
sides, center of carapace with a well-marked H-
shaped depression. Front and side margins raised,
beaded, or serrulate, lateral margin continued into

%jL

Figure 208.— Ocypode quadrata (Fabricius). A, female
in dorsal view, reduced (after Gmitter and Wotton,
1953) ; major chela of male, B, outer view, C, inner view,
reduced (after Crane, 1941).

a prominent, acute angle at outer corner of orbit;
a similar but lower ridge extending upward and
forward from base of third walking leg. Orbits
large and open, extending all along anterior mar-
gin on either side of narrow front, both upper and
lower margins crested and dentate. Eyestalks
large, club-shaped, cornea covering over half of
distal article. Front deflexed ; antennules and an-
tennae much reduced, flagellum of antennules
hidden beneath front.

Chelipeds in both sexes, and in young, unequal,
well developed, rough; merus serrulate above,
toothed on lower margins; carpus with sharp
spines at inner angle; hands coarsely scabro-
tuberculate, margins of palm and fingers dentate,
fingers pointed. Large hand with a vertical strid-
ulating ridge of tubercles on inner surface near
base of movable finger that plays against smooth,
distal, anteroventral ridge of ischium. Walking
legs almost smooth, fringed with long, stiff, yel-
low hair, third pair longest, fourth shortest; meri
of first three pairs broadened; propodi of these
legs with longitudinal brushes of hair on anterior
surface; dactyls of all legs fluted, depressions
hairy.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

225

A hair-fringed breathing slit on ventral surface
between basal articles of third and fourth walk-
ing legs.

Measurements. — Carapace: male, length, 44
mm. ; width, 50 mm.

Color. — Gray, pepper-and-salt, grayish white,
pale yellow, straw color, or yellowish white im-
itating color of beaches; sometimes light amber
and often iridescent; yellow markings below and
and on legs; young mottled gray and brown
(various authors) .

Habitat. — This species, the most terrestrial of
the decapod crustaceans in the Carolinas, lives in
abundance along the ocean beaches and sometimes
on harbor beaches. The crabs construct burrows
2 to 4 feet in depth from near the high-tide line
to distances up to a quarter of a mile from the
ocean.

Type locality. — Jamaica.

Known range. — Block Island, R.I., to State of
Santa Catarina, Brazil (megalops have been
taken at Woods Hole) .

Remarks. — The ghost crabs are so large, accessi-
ble, and widely distributed that they have been
extensively investigated in various parts of their
range.

Perhaps because of its mode of life, this animal
has left a fragmentary fossil record. Rathbun
(1935) recorded 0. quadrata questionably from
the Pleistocene of Florida. Hayasaka (1935)
compared the "sandstone pipes" commonly found
in certain Tertiary sandstones of Formosa to
plaster casts of burrows made by the Formosan
crab, 0. ceratophthalma, and found them to be
much alike. Burrows of the modern Formosan
and eastern North American species are similar.

The egg-laying season in the Carolinas appears
to extend from April (Coues, 1871) to July. Ap-
parently the egg-bearing period is approximately
the same farther south at Tortugas, Fla. (Cowles,
1908), and farther north in New Jersey (Milne
and Milne, 1946). The latter authors pointed out
that ovigerous females differ in behavior from
other individuals in that they wade in water more
freely, run along on the bottom, and at intervals
when the water is quiet open the abdomen out,
flip upside down, extend the mouthparts, rotate
the legs, and, thus, force water through the egg
mass. Such females will run quickly to water
when disturbed. The free-swimming zoea of this

species has not been described, but the megalops
was first described by Say (1817) as Monolepi-s
inermis. Smith (1873a, 1873b, 1880b) recognized
the true status of the form, and pointed out that
though this megalops is carried as far north as
Vineyard Sound by the Gulf Stream, that area is
apparently too cold to support an adult popula-
tion.

Habits of O. quadrata have been treated in a
number of scholarly and popular works, but the
serious student is referred especially to Cowles
(1908) and Milne and Milne (1946). A popular
account of some value, except for the concluding
conjectures, was given by Phillips (1940). Only a
brief summary from these authors can be given
here.

The young crabs are found close to shore. Bur-
rows of the young are near the water and extend
to water level or are covered by high tides for a
time, whereas older crabs burrow farther from
water; such burrows seldom are deep enough to
reach water level. Burrows are of three general
types : ( 1 ) a short vertical burrow made by young
crabs, (2) a burrow sloped downward at about 45
degrees away from the shoreline, often with a
vertical branch extending upward almost to the
surface, and (3) burrows higher on the beach,
much like the second type but without the vertical
side branch. In fall in New Jersey, the burrows
were found to be farther from water and far
deeper than any studied earlier in the year, and
it is presumed that a variety of sizes of crabs
hibernate in these deep burrows.

Burrow making is primarily an occupation of
daylight hours. The crabs cease feeding on the
wet beach toward dawn. Those feeding on a fish
carcass often burrow within an inch or two of the
carcass. Young crabs near water make new bur-
rows, older ones range inland and build burrows
or occupy old holes. Sand is brought to the mouth
of the burrow and dropped or spread near the
opening in a fan-shaped area. Toward noon,
openings to burrows are plugged with damp sand,
thus concealing the burrow. Toward evening the
crabs begin to emerge again, and by 10 p.m. the
whole population is usually on the beach.

These crabs are scavengers (and cannibals) and
tend to feed most actively along the drift line,
looking for beached fish or refuse and small bits
of food buried in the top layer of sand. The crabs

220

FISH AND WILDLIFE SERVICE

do not enter the water to search for or capture
food.

The crabs have to go into the water at intervals
to moisten the gills, and the young do this more
frequently than adults. When undisturbed, the
individuals do not actually enter water but will
stop a few inches from the waterline with one side
presented to the water, the legs of the other side
anchored in sand, and wait for a wave to wash
over them after which they return to the higher
parts of the beach. If disturbed, the crabs will
run into the water, then leave it as soon as possi-
ble. These crabs do not swim but walk on the bot-
tom or are rolled about by waves. The crabs can
survive for a limited time if forced to remain
submerged.

Locomotion is accomplished by all eight walk-
ing legs. Usually the crabs walk sideways or
obliquely. If hotly pursued, the crabs will run in
another manner, holding the last pair of legs clear
of the ground. Usually the crabs walk or run
toward the side with the small chela. This crab
can also walk forward, or sometimes approach
food by walking slowly backward.

The eyes of 0. quadrat a are so large and promi-
nent that it seems as if the crab can see exception-
ally well. Experiment has shown that the eyes are
primarily sensitive to large changes in intensity of
light. The crabs do not tend to avoid strong light,
but try to hide if lights are suddenly shut off or if
an object on the beach is suddenly moved. The
eyes apparently aid in the search for food, but
actual detection of food is by taste or smell.

There is no evidence that 0. quadrat a can hear,
though a well-developed stridulating ridge is
borne on the large chela. No one has reported
observing this crab in the act of stridulating.

Cowles (1908) noticed that the ghost crab ex-
hibits color changes. The crabs are generally dark
in subdued light and in direct sunlight if tem-
perature is not above 35° C. Above 35° C, the
crabs are light colored regardless of light inten-
sity. In absence of light, the crabs are light col-
ored regardless of temperature.

The general relationship of habitat to oxygen
consumption and general activity among certain
decapods has been a subject of study by Ayers
(1938), Pearse (1929), Vernberg (1956), and
Gray (1957) in the Beaufort, N.C., area. In all
these studies, O. quadrata was of prime interest

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

because of its terrestrial adaptation combined
with great activity. Of all the crabs studied in
this geographic area, the ghost crab possesses the
highest rate of oxygen consumption both for the
whole animal and for gill tissue alone. This is
more striking when it is emphasized that O. qua-
drata has a reduced number of gills (though it
does have accessory respiratory tissues in the gill
cavity) and the gill area per gram of weight in
this species is by far the lowest among 16 species
studied in near-shore, intertidal, and above-tide
zones.

Flemister and Flemister (1951) and Flemister
(1958) have shown that when 0. quadrata is con-
fined in water, oxygen consumption is elevated,
but elevated least when chloride ion concentration
of the water equals that of the blood. Lower or
higher ion concentration of the water raises the
respiration rate. They demonstrated that the ani-
mals normally have blood hypotonic to sea water.
In sea water containing less than 120 or more
than 160 millimoles of chloride per liter, the in-
ternal concentration is not maintained but tends
to rise or fall depending on which end of this
range the animal experiences. The antennal gland,
aided by the gill membranes, functions in regula-
tion of internal chloride ion concentration.

Genus Uca Leach, 1814

Rathbun, 1918b, p. 374. — Monod, 1956, p. 399.

KEY TO SPECIES IN THE CAROLINAS

a. Large cheliped of male with oblique tubereulate ridge
on inner surface of palm extending upward from lower
margin.

b. A prominent transverse depression behind orbit ; leg
joints red on large cheliped ; color dark, usually gray-
ish toward front margin minax (p. 227).

bb. Without prominent transverse depression behind
orbit ; leg joints not red ; color dark, often with blue

on front pugnax (p. 229).

aa. Large cheliped of male without oblique tubereulate
ridge on inner surface of palm extending upward from
lower margin pugilator (p. 232).

Uca minax (Le Conte). Red-jointed fiddler; brackish

water fiddler

Figures 209A, 210B

Gelasimus mitmx Le Conte, 1855, p. 403.
Uca minax: Rathbun. 1918b, p. 389, pi. 137 (rev.). — Hay and
Shore, 1918, p. 451, pi. 37, fig. 3.

Recognition characters. — Carapace subquadri-
lateral, approximately 1.3 times as wide as long,
widest behind outer orbital angles, convex in both

227

Figure 209. — Large chela of male, view of inner side ; A,
Uca minax (Le Conte) ; B, Uca pugnax (Smith) ; C,
Uca pugilator (Bose) ; 20 mm. indicated.

directions, finely granulate, except somewhat
coarsely so near anterolateral angles; a shallow7
H-shaped depression near center of carapace, and
a horizontal depression behind orbit. Lateral
margins nearly vertical ; anterolateral angles
slightly produced, continued backward and in-
ward as a low, well-defined ridge, and above orbits
as a low revolute ridge. Front greater than one-
third frontoorbital width, broadly convex. Orbits
large, open, eyebrow 5 times as wide as deep, lower
margin dentate; eyestalks long, slender. Anten-
nules and antennae small, flagellum of antennules
hardly visible. Merits of second maxilliped with
never more than 10 exceedingly slender spoon-
shaped hairs.

Chelipeds in male very unequal, in female equal
and of small size. Large chela with upper surface
of merus sparingly granulate, inner edge denticu-
late, outer edge granulate; carpus tuberculate.
Upper and outer face of large hand in male with
tubercules diminishing to granules on lower face,
ridged al>ove; inner surface with an oblique row
of granules from lower margin to carpal cavity,
a short curved row leading down from ridge on
upper margin, area between ridges tuberculate

and with a tuberculate ridge running along im-
movable finger from tip to internal distal border
of palm. Fingers strong, with wide gape, cutting
edges tuberculate; immovable finger with a few-
larger teeth at irregular intervals, truncate at tip ;
dactyl longer and curving downward past tip of
opposed finger. Walking legs strong, sparsely
hairy, meri slightly wrinkled.

Measurements. — Carapace : male, length, 25
mm. ; width, 38 mm.

Color. — Chestnut brown, becoming gray in
front; chelipeds with red spots at articulations;
hands ivory white ; legs olive or grayish brown.

Habitat.— This species occurs in marshes at
some distance from water of high salinity. It is
usually found on muddy substrates where flood-
ing with fresh water occurs (Teal, 1958), or on a
mud and sand substrate (Gray, 1942). In North
Carolina, the species is found in Spartina marsh,
often far from banks of ditches, and in the area
immediately preceding the Salicornia-Disticlilis
zone (Vernberg, 1959). It has also been observed
at the edge of low woodlands (Teal, 1959). The
crabs live in burrows which they dig to various
depths, but the maximum is about 2 feet. The
openings are often considerably above high-tide
level, and the bottoms reach to ground-water level.
The burrows are only wide enough to accommo-
date the occupant. Usually only one crab lives in
a burrow, though at times two females may oc-
cupy a single burrow, and burrows of females
sometimes communicate with burrow's of males,
the connection being made by the female (Gray,
1942). Young crabs are sometimes found in the
burrows of females, never in those of males.

Type locality. — Beesleys Point, N.J.

Known range. — Buzzards Bay (Wareham),
Mass., to Matagorda Bay, Tex.; Colombia; Do-
minican Eepublic.

Remarks. — This species has been the subject of
a number of ecological and physiological studies,
undoubtedly because of its wide distribution and
accessibility. It is the largest of the three species
of fiddler crabs occurring on the east coast of the
United States, though it is not so abundant as
the other two species and its habitat is somewhat
more restricted.

Spawning occurs in the Carol inas and as far
north as mid-Chesapeake Bay in summer. In
Chesapeake Bay, ovigerous females are most

228

FISH AND WILDLIFE SERVICE

abundant in July; none are known to occur be-
fore July or after the first week in September,
and about the same length of breeding season is
found in the Beaufort, N.C., area. Gray (1942)
presented evidence for two spawnings per season.
The act of egg laying has not been studied in
minute detail, but Gray (1942) observed egg dep-
osition among captive females held in aquaria.
Completion of spawning was usually accom-
plished in a day but sometimes took as long as 3
days, depending on temperature. (Hyman (1920)
and others have dug ovigerous females from bur-
rows.) Freshly laid eggs were yellow or pale
orange in color, but the color changed with de-
velopment through a purplish-black to an ashy
gray color, at which stage the larvae emerged
(see also Hyman, 1920). Estimated egg counts on
a number of ovigerous females ranged from 10,000
to 300,000, depending on size of the individual.
Newly laid eggs measured about 0.09 mm. in di-
ameter but increased to about 0.27 mm. at the time
of hatching. Both Hyman (1920) and Gray
(1942) observed that the females entered water in
order to let the eggs hatch. Time of hatching ex-
tended from about 7:00 to 10:00 p.m., and the
hatching of an egg mass required slightly less
than an hour.

The first zoeal stage of U. minax is the smallest
among our three species of TJca. The larval stages
are discussed in the remarks on U. pugilator.

Uca minax is an omnivorous feeder but avoids
highly putrified debris (Gray, 1942). Teal (1958)
showed that fiddler crabs can subsist on a mixture
of sand, clay, bacteria, and fermented marsh
grass (natural staples in their diet), and he ob-
served U . minax kill and eat U. pugnax and U.
pugilator on several occasions. Contrary to the
findings of others, he observed (1959) that U.
minax can and does feed underwater. Miller
(1961) compared the mouthparts of U. minax to
those of the more specialized Carolinian Ucas.
He found that it prefers to feed in low areas of
the Spartina marshes well up in estuaries where
mud is fluid.

In a search for factors that might limit U.
minax to its particular habitat, Teal (1958)
found that the temperatures experienced in nature
had no effect on survival but that the species could
live in fresh water for more than 3 weeks and,
when offered fresh and salt water, U. minax chose

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 O — 65 16

to live in fresh water. When offered a choice of
mud or sand substrates, this species chose mud
either above or under water, but when competi-
tive species of Uca were present fewer burrows
were dug. Teal (1959) found that U. minax had
the lowest rate of oxygen consumption among a
number of marsh crabs investigated (U. pugnax
and pugilator, Sesarma cinereum and reticulatum,
Eurytium limosum, and Panopeus herbstii) which
is contrary to the argument of Ayers (1938) that
the more terrestrial species have relatively higher
rates of metabolism than do aquatic forms. Teal
(1959) and Vernberg (1959) further observed
that U. minax in all probability does not accli-
mate respiratory rate to changes in temperature.
Gray (1957) found gill area per gram of body
weight in U. minax lowest among East Coast Ucas,
Below 20° C, this species is inactive (Gray, 1942;
Teal, 1959). Gray found that U. minax overwin-
ters in burrows just below the frost line.

Sexual display of the males among fiddler crabs
has been a subject of much study and is too com-
plex for complete review here. Crane (1943,
1944) dealt with this subject briefly for U. minax.
In display, the males rear back on the last two or
three walking legs so that the carapace is vertical.
The major cheliped is extended diagonally up to
about half of maximum extension. This position
may be held for minutes, then the cheliped may
be fully extended swiftly and smoothly, and fin-
ally brought back to the half-extended position
in a series of jerks. This movement may be re-
peated about four times rather slowly. The small
cheliped is moved asynchronously in similar mo-
tions.

Uca pugnax (Smith). Mud fiddler

Figures 209B, 210A

Oelasimus pugnax Smith, 1870, p. 131, pi. 2. fig. 1, pi. 4,
figg. 2-2d.

Uca pugnax: Rathbun, 1918b, p. 395, pi. 139.— Hay and Shore,
1918, p. 451, pi. 37, fig. 4. — Tashian and Vernberg, 1958, p. 89
( rev. ) .

Recognition characters. — Carapace subquadri-
lateral, approximately 1.5 to 1.75 times as wide
as long, widest behind outer orbital angles, very
convex anteroposteriorly, lower edge of front and
upper margin of orbit invisible in dorsal view,
smooth. A shallow H-shaped depression near cen-
ter of carapace, a pit on branchial region in line
with gastro-cardiac sulcus, and a pit behind mid-

229

Figure 210. — Tips of right abdominal appendages of adult
males, hairs omitted ; A, Uca pugnax, anterior view ; B,
Uca minax, anterior view ; C, Uca pugilator, anterior
view; D, same, lateral view (after Crane, 194.3).

die of orbit. Anterolateral angles slightly pro-
duced, continued backward and inward as a low,
well-defined ridge, and across entire frontoorbital
width. Front about two-sevenths of frontoorbital
width, margin regularly arched. Orbits large,
open, upper margin sinuous and oblique, lower
margin dentate. Eyestalks long, slender. Anten-
nule and antenna small. Merus of second maxil-
liped with between 10 and 20, rarely 25, spoon-
tipped hairs.

Chelipeds in male very unequal, in female equal
and of small size. Large cheliped of male rough;
merus with granulated rugose lines outside, lower
margins granulate. Carpus and palm tuberculate
outside; inner surface of palm with oblique row
of granules leading from lower margin to carpal
cavity; a short row leading down from ridge of
proximal half of upper margin; area between
crests coarsely granulate or tuberculate and with
tuberculate ridge running along finger from tip to
internal distal border of palm. Fingers long, slen-
der, widely gaping; immovable finger usually
with one large tooth near middle, inferior border
nearly straight, tip sometimes depressed, trun-
cate; dactyl evenly denticulate and with irregu-
larly placed large tubercles, strongly curving
downward past tip of opposed finger. Walking
legs with carpal and propodal articles hairy.

Measurements. — Carapace: male, length, 15
mm. ; width, 23 mm.

Variations. — There is a tendency toward de-
crease in size in the southern extremity of the
range (Tashian and Vernberg, 1958).

Color. — Carapace of male dark greenish olive,
middle and anterior portion mottled with grayish
white; front variably light blue between and

above bases of ocular peduncles, margin tinged
with brown ; large cheliped lighter than carapace,
pale brownish yellow at articulations and along
upper edge of dactyl, fingers nearly white along
opposed edges; ocular peduncles and eyes much
like dorsal surface of carapace; smaller cheliped
and legs somewhat translucent and thickly mot-
tled with dark grayish olive; sternum and abdo-
men mottled ashy gray. Females less mottled with
white dorsally, and without blue on front (vari-
ous authors) .

Habitat. — Pearse (191-1) recorded this species
as living primarily on intertidal flats of mud or
clay among the roots of Spartina, but overlapping
to some extent the sandier habitat frequented by
U. pugilator. He found the maximum number of
burrows about 2 feet below high-tide mark, and
often the burrows had mud towers at the mouths
when the beach was littered with debris. Crane
(1943) observed "shelter building" in this species
to be in its most rudimentary form among the
Ucas. She found that in a mixed population of
U. pugnax and U. pugilator. U. pugnax always
chose the side of any surface irregularity for a
hole entrance in preference to flat ground. Pearse
(1914) found burrows extending fo 2 feet in
depth and terminating at the water level. Teal
(1958) reported burrows on Georgia Sea Islands
to be in situations similar to those observed by
Pearse, on low levees bordering tidal creeks dr
farther from creeks in firm, marshy ground some-
times covered only at spring tides. Schwartz and
Safir (1915) found U. pugnax burrows on a
muddy substrate well shaded by marsh vegeta-
tion; hence, continually moist. P. pugnax digs
most actively when the tide is falling, and often
hastens to plug burrows when the tide is rising to
cover the burrow mouths (Pearse, 1914).

Type locality. — New Haven, [Conn.].

Known range. — Cape Cod, Mass., to near St.
Augustine, Fla. (Tashian and Vernberg, 1958) ;
northwest Florida to Texas (Hedgpeth, 1950).

Remarks. — Like the preceding species, U. pug-
nax is an abundant and easily accessible, rela-
tively large decapod which has received the at-
tention of numerous students. Only information
of greatest general interest can be mentioned here.

The fossil record for this species extends only
into the Pleistocene of New Jersey and Delaware
(Rathbun, 1935).

230

FISH AND WILDLIFE SERVICE

Ovigerous females have been observed near
Woods Hole, Mass., from July 4 to July 15
(Pearse, 191-4), wandering about over the ground.
Farther south the spawning season is more ex-
tended, from early July to mid-August in New
Jersey (Crane, 1943), and as early as May 21 at
Long Lake, Tex. (Hedgpeth, 1950), and in April
in northeastern Florida (U.S. National Museum
records). On Long Island, N.Y., the peak of
spawning occurs in August (Schwartz and Safir,
1915). Crane (1943) thought it likely that in the
region near New York two breeding times occur,
one in July and the other in August.

The larval and postlarval stages are discussed
in the remarks on U. pugilator. Hyman (1920)
secured ovigerous females for hatching of eggs by
digging them from burrows. He found the first
zoea of V. pugnax to resemble closely that of U.
pugilator except for smaller size of the former.

Schwartz and Safir (1915) found the food of
Ucas to consist largely of minute algae left on
sand by the outgoing tide. Such algae were picked
up by means of the small cheliped in males; fe-
males, using both small chelae, secured more food
in a given time than males. The small chelipeds
seemed sensitive to such food, for they were
dragged along on the sand while the animals
searched for food. Much sand was taken up with
the food. Rapidity of movement of the small
chelipeds to the mouth was timed and found to be
from 24 to 26 times a minute in males, and from
74 to 92 times per minute in females. Teal (1958)
found that U. pugnax frequently feeds under-
water, and that it often remains outside burrows
and feeds as the tide rises. This species can sub-
sist on bacteria and organic debris. Miller (1961)
in his well-illustrated study considered U. pugnax
to be intermediate in development of spoon-
shaped hairs on the mouth parts and, therefore,
more ubiquitous in choice of feeding substrates
than its congeners in the Carolinas. Great detail
is given in this study.

In experiments on salinity tolerance, Teal
( 1958 ) found that 50 percent of U. pugnax placed
in fresh water died within 1.5 days. In water of

7 %o> 50 percent mortality occurred after 3 days.
Given a choice of fresh or 30 °/00, U. pugnax chose
salt water. Teal concluded that these data are

consistent with the general distribution of the spe-
cies, which is restricted to tidal marsh.

Given a choice of sand or mud substrate above
or under water, U. pugnax burrowed only in mud
without any reference to water level, and com-
petitive species of Uca had no significant effect
on numbers of burrows dug. When restricted to
the relatively high Salicomia-Distichlis marsh, U.
pugnax survived less well than U. pugilator.

Respiration rates for U. pugnax are higher un-
derwater than in air (Teal, 1959), probably be-
cause of increased activity necessary to ventilate
the gills.

At normal habitat temperatures, U. pugnax
(=rapax) from Trinidad showed a higher meta-
bolic rate than from localities in the United States
(Tashian, 1956). Tashian found that there is a
decrease in sensitivity to temperature change from
southern to northern populations, along with an
increase in tolerance to low temperature. Teal

(1958) found that temperatures experienced in
nature are not limiting factors in distribution of
U. pugnax in Georgia, though high temperatures,
near a lethal level occur at times in summer. He

(1959) concluded that among marsh crabs studied
(see "remarks U. minax''), U. pugnax exhibits
the most highly developed thermal acclimation,
and its abundance on the marshes may be ex-
plained in part by its ability to regulate its
metabolism over a wide range of temperature.
Vemberg (1959) and Vernberg and Tashian
(1959) reinforced this conclusion, showing that
U. pugnax exhibits a marked tendency to demon-
strate seasonal thermal acclimation. Brett (1960)
showed that the daily oxygen-consumption cycle
is considerably modified by locomotion of the
crabs. Gray (1957) found gill area per gram of
weight in U. pugnax to be lowest among the East
Coast Ucas.

Crane (1943) observed hibernating U. pugnax
in New Jersey, where the burrows were weathered
open along the muddy banks of small creeks and
could only have been submerged at spring tides.
In March at air temperatures of 1.7° to 5.5° C,
the immobile crabs were found from the burrow
mouths to about 4 inches below the surface. Slight
warming in the hand or in the sun elicited fairly
rapid movement.

In another vein, Passano (1960) found an in-
verse correlation between temperature and pro-

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

231

ecdysis duration in II. pugnax. Surprisingly, at
some temperature between 15° and 22° C. pro-
ecdysis fails to proceed normally, though these
animals experience much lower temperatures
throughout their range. It was suggested that
the northern limits of the species are influenced
by the inability of larvae to molt in cold water;
hence, adults cannot appear there.

Crane (1943) gave a detailed description of the
display and breeding relationships for this spe-
cies. Display of males starts with the body ele-
vated moderately high and both chelae held well
off the ground and flexed in front of the mouth.
Both chelipeds are extended obliquely upward,
then the major claw is returned downward in a
jerk or a series of jerks with no pause between
extension and flexion. The fingers usually remain
nearly closed, and a complete cycle of movement
usually requires about 2 seconds. (Movement of
the small chela is not described.) At times males
will exhibit a series of bobbings or "curtseys,"
especially when displaying to females. Pearse
(1914) and others considered these activities to
be courtship display.

Other activities which have received much at-
tention in experiments are rhythmic cycles.
Brown and his coworkers (Brown and Sandeen,
1948; Brown and Webb, 1948, 1949; Brown,
Webb, Bennett, and Sandeen, 1954) showed that
fiddler crabs (among them U. pugnax) exhibit
temperature-independent, diurnal, rhythmical
color changes. These rhythms may be altered, or
delayed, by lowering temperature for a time, or
by, altering the period or time of illumination.
They further demonstrated that possibly two cen-
ters of rhythmicity exist in these crabs, each capa-
ble of having its rhythm altered independently of
the other, and with one center influencing the
other. Brown, Fingerman, Sandeen, and Webb
(1953) demonstrated that amplitude of diurnal
cycles under constant conditions increased to a
maximum in 2 weeks. Superimposed on diurnal
cycles are tidal rhythms which persist in phase
witli native local conditions under constant labor-
atory conditions. Oxygen consumption reflects
these cycles as well as a lunar cycle (Brown, Ben-
nett, and Webb, 1954; Brown, Fingerman, and
ITines, 1954; Brown, Webb, Bennett, and San-
deen, 1955). Bennett, Shriner, and Brown (1957)
found that degree of spontaneous locomotor ac-

tivity is also related to tidal cycles although the
rhythm persists only about a week under constant
conditions.

Primarily because of the tremendous asym-
metry in chelipeds of male fiddler crabs, Uca be-
came an object of studies on relative growth. (In
some of these papers no clear species designation
was made.) In fiddler crabs [Uca pugnax\ the
percentage weight of the chela alters throughout
life from 2 percent (the value retained by the
female) to 65 percent (Huxley, 1927). In the re-
lated larger species, U . minax, since allometric
growth continues longer, the chela may weigh
over three-fourths of the remainder of the body
(77 percent ) . Increasing relative size of the chela
is associated with an increasing asymmetry of the
central nervous system. Thus, such animais have
no fixed form, for the proportions of parts are
changing throughout postlarval life. On this
basis, Huxley challenged Morgan's (1923) state-
ment that females with intermediate width abdo-
mens (subject also to allometric growth, Huxley,
1924) were actually intersexual female types.
Tazelaar (1933) explored the subtleties of relative
growth in U. pugnax in detail, finding that walk-
ing legs near the great chela and near the wide
abdomen of females also reflect relative growth
influences.

Uca pugilator (Bosc, [1801 or 1802]). Sand fiddler

Figures 209C ; 210 C, D ; 211

Ocypoda pugilator Bose, [1801 or 1802], p. 197.
Uca pugilator: Rathbun, 1918b, p. 400, pi. 141 ; pi. 160, fig. 2
(rer.).— Hay and Shore, 1918, p. 452, pi. 37, fig. 2.

Recognition characters. — Carapace subquadri-
lateral, up to 1.5 times as wide as long, widest be-
hind outer orbital angles, very convex, smooth; a
shallow H -shaped depression near center of cara-
pace and a narrow, flattened shelf behind orbit.
Lateral margin strongly curved outward behind
orbit, continued backward and inward as a low,
well-defined ridge across entire frontoorbital
width. Front more than one-third of frontoorbital
width, broadly rounded below. Orbits large, open,
upper margin slightly sinuous, lower margin den-
tate. Eyestalks long, slender. Antennule and
antenna small. Merus of second maxilliped with
150 to 200 spoon-tipped hairs arranged in about 10
rows on inner side.

Chelipeds in male very unequal, in females
equal and small. Merus of large chela with short,

232

FISH AND WILDLIFE SERVICE

Figure 211. — Vca pugilator (Bosc). Male in dorsal
view, about natural size (after Rathbuu, 18S4).

granulated, rugose lines above and with isolated
dark hairs proximally, nearly smooth outside,
lower margins granulate; merus of small cheli-
peds with scattered hairs. Carpus and outer sur-
face of large hand with tubercles diminishing to
granules on lower face of hand. Inner surface of
palm without oblique tuberculate ridge as in U.
minax and V. pugnax, but with a tuberculate
ridge running along immovable finger from tip
backward on internal distal border; surface gran-
ulate, granules coarser on thickest part of palm.
Fingers strong, gaping; immovable finger with
largest tubercles just behind middle and near
truncate tip, inferior surface convex; dactyl
evenly denticulate and with irregularly placed
large tubercles, strongly curving downward past
tip of opposed finger. Walking legs narrow.

Measurements. — Carapace: male, length, 17
mm. ; width, 26 mm.

Color. — Carapace of male a dull light purplish
or grayish blue of varying shades, or with ir-
regular markings of brown or dark gray, a large
patch of deep purplish blue on anterior half;
large cheliped dull light blue at base with white
tubercles, articulations yellowish; fingers mostly
white; small chelipeds and legs buff with blue or
brown speckles (various authors). Specimens
from Massachusetts, bluish gray; those from Flor-
ida, reddish yellow (Demeusy, 1957).

Habitat. — This species occurs in countless num-
bers on sandy and muddy beaches bordering
marshes, and along banks of tidal creeks. The
crabs also occur farther from water in sandy situ-
ations of the Salicornm-Distichlis marsh and at
times in Juncus marsh where the soil is sandy
(Teal, 1958). The species burrows much as does
V. pugnax, and populations of the two species are

often intermingled (Pearse, 1914), though V.
pugilator prefers sandier situations (Hyman,
1922). Dembowski (1926) found that choice of a
place to burrow depends upon many factors,
among them phototaxis and thigmotaxis. Bur-
rows may have any shape but are unbranched and
usually dug at an angle to the surface of the
ground, the length of the burrow depending in
part on the amount of moisture in the ground.
Digging by males is done with legs on the side
opposite the large claw. The crabs plug the open-
ing as soon as they feel the water level rising in
the burrow with the tide, and do this by pulling
in the edges of the burrow and by ramming sand
up from below. The end chamber, thus, functions
as an air chamber during high tide.

Type locality. — "Caroline."

Known range. — Boston Harbor, Mass., to
Texas; Old Providence Island (Coventry, 1944) ;
Haiti.

Remarks. — Vca pugilator, like its east Ameri-
can congeners, has been the subject of much study,
and one of the most readable accounts of its nat-
ural history is that of Hyman (1922).

In the vicinity of Beaufort, N.C., ovigerous fe-
males are found in spring and early summer. In
Virginia, they are known from March to July
(U.S. National Museum records). Schwartz and
Safir (1915) found ovigerous females at Long Is-
land, New York, from the first week in July until
mid- August; in Massachusetts, Pearse (1914)
found no ovigerous specimens until the first part
of August. In Texas, Hedgpeth (1950) reported
zoeae taken in a plankton net on May 20 at Long
Lake. The breeding season, thus, is similar to
those of the species discussed above in being sea-
sonally related to latitude. Schwartz and Safir
(1915) and Hyman (1920, 1922) stated that ovi-
gerous females were rarely seen at the surface, but
Hyman found that they left their burrows to
aerate the eggs in water for a time at dusk. When
the eggs were ready to hatch, the zoeae were re-
leased at such time in the water.

The larval and postlarval stages of the East
Coast species of Vca were described and illus-
trated by Hyman (1920) based largely on study
of V. pugilator. Hyman could find no consistent
morphological differences among each stage of the
three species. Five zoeal stages and a megalops
stage were described. Gray (1942) described a

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

233

transitory prezoeal stage. Hyman found the first
two zoeal stages most abundant at the surface, the
third probably at intermediate depths, and the
fourth and fifth zoeae usually on the bottom. He
found the zoeal stages to last collectively about a
month.

The megalops, a single stage lasting nearly a
month, is a powerful swimmer. At the end of
this stage the animal retires to cover of some sort,
molts through two relatively weak crab stages and
at last emerges as an active small crab measuring
about 2 mm. across the carapace.

Feeding movements in U. pugilator are essenti-
ally the same as in the other two species of Uca
and are discussed in the account for U. pugnax.
Schwartz and Safir (1915) found the males moved
the small cheliped to the mouth 28 to 46 times per
minute, and females 61 to 92 times, when actively
feeding on small particles in sand. Teal (1958)
found that this species may wander into tide pools
and shallow creeks to feed underwater at low
tide. Miller (1961) considered U. pugilator to be
the most specialized in mouth parts among Caro-
linian TJcas and well adapted to feeding on coarse
substrate such as protected sandy beaches.

In experiments on salinity tolerance, Teal
(1958) found that in fresh water 50 percent of U .
pugilator died after 3.5 days. In water of 7 °/00
more than 50 percent of the animals survived a
10-day test. Given a choice of fresh or 30
700 sea water, U. pugUator chose salt water,
but preferences shown by females were less strong
than those shown by males, as was true also of
U.*pugnax. Teal concluded that this species lies
between U. minax and U. pugnax in its tolerance
of fresh water and can survive soakings of the
Salicornia marsh with rain between spring tides.

Given a choice of sand or mud substrate above
or underwater, U. pugilator burrowed almost ex-
clusively in sand above water level. When either
of the other species of Uca was present as a com-
petitor for space, there was a reduction of 50
percent in the number of burrows that U. pugila-
tor dug in sand above water. In tanks where
there was no favorable substratum of sand above
water, its behavior was not changed by presence
of another species. When restricted to an unfavor-
able, low, muddy marsh, U. pugilator did not sur-
vive. Teal conjectured that this species cannot
feed properly where sand is absent.

Respiration rates for this species are higher
underwater than in air (Teal, 1959), probably
due to increased activity necessary to ventilate the
gills.

Teal (1958) found that temperatures of 45° C.
on open sand flats of the Salicornia-Distichlis
marsh in Georgia prevent U. pugilator from
permanently occupying these areas, though they
do feed there in cooler parts of the year. In gen-
eral, temperatures experienced in nature were not
considered a limiting factor. Orr (1955) found
that U. pugilator died in 81 minutes at 40° C, in
18 minutes at 41° C, in 9 minutes at 43° C. and
in a little less than 9 minutes at 46° C. Demeusy
(1957), investigating respiratory rates in popula-
tions of this species from Florida and Massa-
chusetts, found that the northern population had
a higher rate of metabolism at low temperatures
(1.4° C.) than the Florida population, but that at
15° C. the difference was not significant, Demeusy
found the northern population less sensitive to
temperature change and more resistant to low
temperature than the Florida population. On the
other hand, Edwards (1950) found metabolic dif-
ferences in these populations at 20° C. Teal
(1959) found that above 25° C. specimens from
Georgia showed no adjustment of respiration for
temperature acclimation, but that below 20° C.
there was some evidence of acclimation though
not so well developed as in U. pugnax. Vemberg
(1959) pointed out that metabolic activity in Uca
of the temperate zone exhibits a seasonal cycle
and that this cyclic change must be taken into ac-
count in comparing physiologic activity of rela-
tives at different latitudes. Moreover, he stated
that metabolic response of fiddler crabs has real
significance in their distribution.

Crane (1943) gave a detailed description of the
display and breeding relationships for this spe-
cies. Display of males starts with the body ele-
vated, cheliped tips lowered, and the meral-carpal
joint of the major cheliped elevated. The cheliped
is then extended up and out, the crab at the same
time raising to tiptoe. The cheliped is held out
for an instant, then smoothly returned to the orig-
inal position. The minor chela makes weak cor-
responding gestures and fingers of both chelae
are nearly closed throughout. Waves are made at
a rate of about one per second. At moments of

234

FISH AND WILDLIFE SERVICE

extreme excitement, the major cheliped may be
rapped against the ground in a flexed position.

Burkenroad (1947b) observed a drumming
sound produced by males vibrating their large
cheliped just outside the burrow at night, or in
daytime just after waving and retreating into the
burrow. Pearse (1914) was never able to ob-
serve copulation in the field following display, but
did observe five matings of captive pairs in the
laboratory. Females mated in the "hard shell''
condition.

Color changes in U. pugilator have been in-
vestigated extensively in recent years. Carlson
(1937) contended that the chromatophores re-
spond to humoral control by the sinus gland in
the eyestalks. Brown and Sandeen (1948) and
Brown and Webb (1948) showed that there is a
rhythmic secretion of hormone which operates to
disperse the black and white pigments in the day
and concentrate these at night. Superimposed on
these responses are responses to background color,
to total illumination, and to temperature, such
that both pigments tend to disperse as intensity
of illumination increases; but black pigment tends
to concentrate as temperature increases above or
decreases below about 15° C, and white pigment
tends to disperse as temperature is increased above
or decreased below about 20° C. Such lightening
or darkening has been recorded in the field by a
number of observers. Brown (1950) extended
Carlson's work on red chromatophores, giving evi-
dence for the activating principles and their daily
rhythmicity. Further experiments with black
chromatophores (Webb, Bennett, and Brown,
1954) showed that the diurnal rhythmic darken-
ing and lightening are independent of structures
in the eyestalks and that a substance which con-
centrates black pigment participates in regulation
of the chromatophore system. Guyselman (1953)
described a series of five color changes or stages
which occur during the premolt period of normal
animals. He found (as suggested earlier by
Abramowitz and Abramowitz, 1940) that the
sinus gland-X organ complex plays a role in regu-
lation of metabolism of water and inorganic con-
stituents. Evidence of a diurnal rhythm of water
uptake was presented. Fingerman (1956) showed
that even in the Gulf of Mexico, where tides are
daily, the persistent rhythmic color changes re-

main scheduled as they are in crabs living where
tides are semidiurnal, but (1957) that for a given
local area the phase may be slightly altered ac-
cording to the time that the burrows are uncov-
ered by a receding tide.

Extending their investigations on rhythmicity,
Brown, Webb, Bennett, and Sandeen (1955)
showed that oxygen consumption in both U.
pugilator and U. pugnax shows apparent persist-
ent trends related to solar and lunar cycles.

As a sidelight to work with eyestalkless U.
pugilator, Brown and Jones (1949) found that
removal of eyestalks from adult females resulted
in a period of rapid ovarian growth, with accom-
panying increase in oocyte diameter and a color
change of the ovary from light pink to deep
purple. Eggs produced by such animals failed to
become attached to the pleopods.

The subject of intersexuality and relative
growth was reopened by Darby (1935) as a re-
sult of examination of some 9,000 specimens of
U. pugilator collected at Beaufort, N.C. Among
these, 12 females were obtained with 2 fiddles, but
no female was found in 1 large chela. These 12
specimens had fully widened, typically female
abdomens and were always found feeding with
the males in contrast to the other small-clawed
females which stayed close to their holes. Darby
termed these female-to-male intersexes. A male-
to-female intersex; that is, a crab with a typical
male abdomen and normal reproductive append-
ages, yet with small claws, was found only once,
at Charleston, S.C. Because feeding is accom-
plished with the small claw, even partially sym-
metrical males must be handicapped in obtaining
food, and it is not surprising that perfectly sym-
metrical adults do not, or rarely, occur. Darby,
thus, refuted the arguments of Huxley and Rath-
bun that females with narrow abdomens were
merely extremes in the normal variation curve for
female abdomen growth, and supported the con-
tention of Morgan that these were truly intersexes.

Superfamily Oxyrhyncha

Carapace more or less narrowed in front, and
usually produced to form a rostrum; branchial
regions considerably developed, hepatic regions
small. Epistome usually large; buccal cavity
quadrate, with anterior margin usually straight.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

235

Gills almost always nine in number on each side;
efferent channels opening at sides of endostome or
palate. Antennules longitudinally folded (Rath-
bun, 1925).

Family Majidae

Chelipeds specially mobile, usually about same
size as other legs with fingers straight. Second
article of antenna well developed, generally fused
with epistome and often with front. Orbits gen-
erally more or less incomplete. Hooked hairs al-
most always present. Male openings coxal (Borra-
daile, 1907). Palp of external maxilliped articu-
lated either at summit or at anterointemal angle
of merus (Alcock, 1895). First pleopod greatly
exceeding second pleopod in length (Garth, 1958).

KEY TO SUBFAMILIES OF MAJIDAE IN THE
CAROLINAS

Modified after Garth (1958)

a. Eyes either without orbits, or with commencing orbits,
b. Eyes without orbits ; eyestalks generally long, either
nonretractile, or retractile against sides of carapace,
or against acute postocular spine affording no con-
cealment; basal (fused) antennal article extremely

slender and usually long Inachinae (p. 236).

bb. Eyes with commencing orbits; basal (fused) an-
tennal article not extremely slender,
c. Eyes lacking a postocular cup, but with tubelike
housing.

d. Eyestalks long ; orbit partially protected by a
hornlike supraocular spine or eave, a strong
postocular tooth, or both ; body truncate in front
Ophthalmiinae (p. 246).
dd. Eyestalks short, relatively immobile, and either
concealed by a supraocular spine, or sunk in
sides of rostrum ; basal antennal article truncate-
triangular Acanthonychinae (p. 248).

cc. Eyes with cupped postocular process into which
eye retracts, and with a supraocular eave or spine

Pisinae (p. 250).

aa. Eyes with complete or nearly complete orbits ; basal

antennal article broad, expanded to form floor to orbit

Mithracinae (p. 254).

Subfamily Inachinae

Eyes without orbits; eyestalks generally long,
either nonretractile, or retractile against sides of
carapace, or against an acute postocular spine.
Basal article of antenna extremely slender
throughout its extent, and unusually long (Al-
cock, 1895). First pleopod not very stout, straight
or curved, apically tapering, but apex most vary-
ing (hairy, spinose, naked, etc.; acute, blunt, bifid,
etc.) ; second pleopod short (Stephensen, 1945).

236

KEY TO GENERA OF INACHINAE IN THE
CAROLINAS

Modified after Garth (1958)

a. Seven free abdominal segments in both sexes ; rostrum

double Anomalothir (p. 236).

aa. Six free abdominal segments in male, five in female,
b. Rostrum double.

c. Interantennular spine present and conspicuous,
d. Spine of basal antennal article equally advanced

with front Eupvognatha (p. 237).

dd. Spine of basal antennal article not equally ad-
vanced with front Batrachonotus (p. 238).

cc. Interantennular spine absent or inconspicuous.

Collodes (p. 239).
bb. Rostrum single.

c. Merus of outer maxilliped as broad as ischium;
palp of moderate size,
d. Postorbital tooth large, curving around side of

eye Pyromaia (p. 240).

dd. Postorbital tooth small, or if large not curving

around side of eye Anasimus (p. 240).

cc. Merus of outer maxilliped often narrower than
ischium ; palp large and coarse,
d. Rostrum considerably less than postrostral
length ; basal antennal article often longitudi-
nally sulcate Podochela (p. 241).

dd. Rostrum approaching or surpassing postrostral
length ; basal antennal article not longitudinally
sulcate.

e. Carapace nodulose; a long spine at end of

merus of walking legs ; rostrum sparsely spined

Metoporhaphis (p. 243).

ee. Carapace smooth ; spine at end of merus of

walking legs no longer than others ; rostrum

multispinose Stcnorynchus (p. 244).

Genus Anomalothir Miers, 1879

Rathbun, 1925, p. 23.

Anomalothir furcillatus (Stimpson)

Figures 212, 223A

Anomalopux furcillatus Stimpson, lS71a, p. 125.
Anomalothir furcillatus: Rathbun, 1925, p. 24, text-fig. 6, pi. 8,
fig. 2 ; pi. 9, fig. 2 ; pi. 206 ( rev. ) .

Recognition characters. — Carapace much elon-
gated, almost subcylindrical, pubescent, with
regularly placed tubercles. Rostrum long, from
two-thirds to 1.25 times as long as remainder of
carapace, bifurcate, horns contiguous for half or
more of length, slightly divergent. Eyes without
orbits; pre- and post-orbital spines small, acute.
Antenna visible in dorsal view, basal article nar-
row. Merus of maxilliped without notch at inner
angle where palp inserts.

( 'helipeds in adults longer than carapace; merus
subcylindrical, with row of small spines below

FISH AND WILDLIFE SERVICE

Figure 212. — Anomalothir furcillatus (Stimpson). Fe-
male in dorsal view, legs of right side not shown, 3 mm.
indicated.

and less distinct row above; carpus with three
spines on outer surface; palm unarmed, elongate;
fingers short, stout, less gaping in male than in
female. Walking legs pubescent; first two pairs
long, slender; third and fourth pairs shorter, pre-
hensile, with dactyls spinose on inner border;
third pair shortest, merus with three strong
hooked spines beneath, propodus and curved
dactyl of about equal length; fourth pair inter-
mediate in length, nearly straight, with propodus
longer than dactyl.

Abdomen of both sexes with seven free seg-
ments.

Measurements. — Carapace : male, length includ-
ing rostrum, 17 mm.; width, 6 mm. Length of
rostrum, 7.5 mm. Carapace: female, length in-
cluding rostrum, 20 mm.; width, 5 mm. Length
of rostrum, 6 mm.

Color. — Light orange yellow; palms much
deeper color (Henderson in Rathbun, 1925).

Habitat. — Rathbun (1925) listed this form
from sandy, broken shell, pebbled, and rocky bot-
toms; 30 to 262 fathoms.

Type locality.— OS. "The Samboes" [Southern
Florida], 123 fathoms.

Knoion range. — Off Cape Lookout, N.C.,
through Gulf of Mexico and West Indies to
Grenada.

Remarks. — Though the depth range of this spe-
cies is usually beyond the 100-fathom mark, it
may occur in shallower water in the Carolinas.
Ovigerous females are known from the north-
eastern Gulf of Mexico in March.

Genus Euprognatha Stimpson, 1871

Rathbun, 1925, p. 95.
Euprognatha rastellifera marthae Rathbun

Figures 213, 223B

Euprognatha rastellifera Stimpson, 1871a, p. 123. — Hay and
Shore, 1918, p. 454, pi. 37, fig. 7.

Euprognatha rastellifera marthae Rathbun, 1925, p. 96, text-
fig. 30, pi. 33 ; pi. 34, figs. 1-2 ; pi. 35, figs. 3-4 ; pi. 216 (rev.).

Recognition characters. — Carapace pyriform,
granulate, a tubercle or short truncate spine on
gastric and cardiac regions, each branchial re-
gion, and supraorbital margin. Rostrum short,
with two small teeth on horns. Ocular peduncles
short, with tubercle at emargination of cornea.
Frontal teeth short, spiniform, or triangular.
Postorbital projection dentiform, triangular, ta-
pering to a slender point. Obtuse antennal spines
directed obliquely forward, approximately as ad-
vanced as front; interantennular spine inclined
downward, equaling or surpassing front. Sides
of hepatic and pterygostomian region with a few

Figure 213. — Euprognatha rastellifera marthae Rathbun.
Male in dorsal view, legs of left side not shown, 5 mm.
indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

237

small spines. Sternum granulate except for con-
cave portion between chelipeds.

Chelipeds approximately twice as long as cara-
pace, granulate, margins spinous; hand swollen;
fingers more than half length of palm, slightly
gaping. Walking legs granulate, with tufts of
curled setae and often small spines; first pair
longest, others successively shorter.

Abdomen of males with six, females with five,
free segments.

Measurements. — Carapace: male, length, 14
mm. ; width, 12 mm.

Variations. — Kathbun (1925) divided the spe-
cies E. rastellifera into a northern subspecies,
marthae (ranging from Nantucket to southern
Florida), and a southern or Caribbean subspecies,
acuta, (ranging from Cuba to Grenada and Barba-
dos), with a region of intergradation in the
Florida Keys from which rastellifera was origi-
nally described. The southern subspecies (acuta)
has longer, sharper, and more slender spines than
marthae, and a narrower, higher, and more closely
and finely roughened carapace with regions more
deeply separated than in the more northern forms.
Likewise, the chelipeds have spines on the border
of the merus well developed and legs more spinu-
lose than in the northern forms.

Rathbun pointed out that there is considerable
overlap in distribution of these subspecies, listing
acuta from as far north as Marthas Vineyard.
Such subspecific treatment seems untenable today,
for such overlap of geographic range can hardly
exist. No typical form was designated. I have
retained the subspecific name marthae for the
Carolinian form simply because this region lies
well within the range mentioned by Kathbun, but
I have not studied all of the material compara-
tively.

Habitat. — The species has been reported from
a variety of sandy and muddy bottoms; 44 to 217
fathoms.

Type locality. — Southwest of Marthas Vine-
yard, Mass., laf . 40° N. long. 70°57' W., 85 fathoms.
Known range. — Off Georges Bank (lat. 40°35'
N. long. 67°37' W.) to Carysfort, Fla.

Remarks. — Kathbun (1925) reported an oviger-
ous female off Mart lias Vineyard in July, and
are known off Georges Bank in November
(U.S. National Museum records) .

Genus Batrachonotus Stimpson, 1871

Rathbun, 1925, p. 122.

Batrachonotus fragosus Stimpson

Figures 214, 223C

Batrachonotus fragosus Stimpson, 1871a, p. 122. — Rathbun,
1925, p. 123, text-fig. 48, pi. 39, figs. 1-4 (rev.).

Recognition characters. — Male. Carapace tri-
angular, broadly expanded behind; gastric, car-
diac, and branchial regions strongly protuberant,
each surmounted by a stout spine or large tuber-
cle; intestinal region with two small tubercles
just above posterior margin ; hepatic region angu-
lar, approximating postorbital tooth. Cervical de-
pressions deep and broad giving carapace superior
outline much like frog's back. Rostrum short,
formed of rounded lobes separated by a shallow
notch, scarcely projecting beyond antennulary
fossae, margin and supraorbital margin denticu-
late. Basal articles of antenna with dentate mar-
gins and a small tooth at anterior extremity.
Merus of outer maxilliped broad with prominent
outer and inner anterior angles. Abdomen and
sternum granulate except for smooth area be-

Figube 214. — Batrachonotus fragosus Stimpson. Animal
in dorsal view. letfs of ri^'lit side shown in approximate
position, le^'s of left side not shown. 2 mm. indicated.

238

FISH AND WILDLIFE SERVICE

tween chelipeds ; abdomen with six free segments,
last two fused, proximal fixed segment with a
prominent median spine.

Chelipeds somewhat longer than carapace,
spinulose; ischium with distal spine; hand slightly
compressed ; fingers nearly as long as palm, gap-
ing nearly whole length, a large tooth in middle
of immovable finger. First pair of walking legs
more than twice length of second pair, posterior
pairs short.

Female. Carapace narrower behind and wider
in front than male, tuberculation more uniform,
spines less frequent. First walking leg little
longer than second, approximately 1.5 times
length of carapace. Abdomen tuberculate or
granulate, with five free segments, last three fused.

Measurements. — Carapace: male and female,
length, 7 mm. ; width, 6 mm.

Variations.— Rathbun (1925) stated that this
species exhibits wide variations from the type.
Some specimens have the elevated regions sur-
mounted by a spine, some have an abdominal
spine, others even lack tubercles on the elevated
regions.

Habitat. — The species has been reported from
mud, sand of various grades, and broken-coral
and shell bottoms ; shore to 75 fathoms.

Type locality.— South of Tortugas, [Fla.], lat.
24°36'40" N. long. 80°02'20" W., 16 fathoms.

Known range. — Cape Hatteras, N.C., to south-
ern and western Florida; West Indies to Rio de
Janeiro, Brazil. Ovigerous females are known
from Tortugas in June (U.S. National Museum
records) .

Genus Collodes Stimpson, 1860

Rathbun, 1925, p. 105.
Collodes trispinosus Stimpson

Figures 215, 223D

Collodes trispinosus Stimpson, 1871a, p. 120. — Rathbun, 1925,
p. 107, text-figs. 32a, b; pi. 36, figs. 5-6 (rev.).

Recognition characters. — Carapace ovate-tri-
angular, covered with coarse granules except on
front, anterior portion of gastric region, and
about bases of spines; a single, slender, erect,
capitate spine on gastric and cardiac regions, and
on first abdominal segment. Rostrum short, with
two minute and usually well-separated horns.
Eyes of moderate length, partially retractile;
postorbital tooth slender, a granule on upper

Figure 215. — Collodes trispinosus Stimpson. Male in
dorsal view, legs of left side not shown, 5 mm.
indicated.

orbital border. Antenna with first movable article
approximately as long as rostral horns; basal
article of antenna twisted, with four or five
spinules on outer border and with a laminate
crest on inner margin ending in a large tooth;
interantennular spine short. Merus of outer
maxilliped obcordate, deeply cut on distal margin,
strongly produced at inner and outer angles.

Chelipeds of male moderately stout, palm thick,
smooth outside; surface of carpus and margins of
merus and palm spinulose ; fingers widely gaping,
with a triangular tooth near middle of immovable
finger and a low molariform tooth near base of
dactyl. Walking legs long ; first two pairs varia-
bly subequal ; third and fourth pairs successively
shorter ; dactyls as long as propodi.

Measurements. — Carapace: male, length, 14
mm., width, 12 mm.; female, length, 12 mm.,
width, 10 mm.

Habitat,— Rathbun (1925) reported this species
from gray sands of varying coarseness, broken
shell, and gravel bottoms; 4 to 82 fathoms.

Type localities. — Off the Quicksands, Carysfort
Reef, and French Reef, [Fla.], 34 to 50 fathoms.

Known range. — Near Cape Hatteras, N.C., to
south and west Florida near Apalachicola.

Remarks.— Rathbun (1925) reported ovigerous
females from North Carolina in October, and
they are known from Florida in July (U.S. Na-
tional Museum records).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

239

Genus Pyromaia Stimpson, 1871

Rathbun, 1925, p. 127.

Pyromaia cuspidata Stimpson

Figures 216, 223E

Pyromaia cuspidata Stimpson, 1871a, p. 110. — Hay and Shore,
1918, p. 455, pi. 38, fig. 4. — Rathbun, 1925, p. 129, text-flg. 49 ;
pi. 41 (rev.).

Recognition characters. — Adult male. Carapace
pyriform, approximately two-thirds as wide as
long; regions well marked, tumid, rough, with
scattered granules, sharp tubercles and spines;
often six large median spines (two nasogastric,
one urogastric, two cardiac, one intestinal), else-
where one protogastric, two or three hepatic, re-
mainder branchial. Depressions separating bran-
chial regions from other regions somewhat pitted.
Rostrum tapering to a point, trigonal ; upper and
lateral margins spinulose. Interantennular spine
acute, triangular, pointing downward and for-
ward. Orbits large, open; supraorbital spine al-
most erect, directed slightly outward and for-
ward; postorbital tooth large, curved around end
of eye; anterior margin fringed with hair. Basal
article of antenna long, with terminal spine, a
larger spine at middle of inner margin and a small
one at middle of outer margin followed by row of
tubercles or spinules. A tubercle at angle of buccal
cavity. Outer maxilliped spinulose, a longitudinal
depression on ischium, merus cordate.

Limbs covered with short fur, surface under-
neath roughened with sharp granules or spines;

Figure 216. — Pyromaia cuspidata Stimpson. Male in dor-
sal view, legs of left side not shown, 10 mm. indi-
cated.

merus of cheliped armed on margins, terminal
spine of upper margin longest; upper margin of
carpus spinulose with a few spines on outer sur-
face; hand inflated, fingers bare, grooved, slightly
agape at base. Walking legs spinulose; meri with
distal spine; first legs longest, remainder succes-
sively shorter.

First abdominal segment long, with an acute
backward-pointing spine; six free segments, last
two fused.

Adult female. Limbs almost bare; chelipeds not
much stronger than walking legs, dactyl longer
than palm; legs shorter than in male. Five free,
abdominal segments, last three fused.

Measurements. — Carapace: male, length, 41
mm. ; width, 32 mm.

Variations. — The young have pubescence re-
sembling that in females, the postorbital tooth
smaller than in adults, slender and directed out-
ward in small specimens (7.5 mm. long), directed
outward and forward in somewhat larger forms.

Color. — Immature individuals brown, legs with
lighter crossbands.

Habitat. — This species has been taken on gray
mud, sand, pebble, and broken-coral bottoms; 15
to 300 fathoms.

Type localities. — Off Sand Key, 82 fathoms;
Alligator Reef, 88 fathoms; the Samboes, 93 and
121 fathoms; southwest of Sand Key, 125 fathoms
[Florida].

Known range. — Off Cape Lookout, X.C., to west
Florida ; Yucatan Channel ; Cuba.

Remarks. — U.S. National Museum records show
ovigerous females off Florida in February and
July.

Genus Anasimus Milne Edwards, 1880

Rathbun, 1925, p. 64.

Anasimus latus Rathbun

Figures 217, 223F

Anasimut latus Rathbun, 1894, p. 58. — 1925, p. 65, pi. 214
(rev.).

Recognition characters. — Carapace broadly
ovate, elevated on median line, posterior half
semicircular, anterior half broadly triangular,
surface covered with unequal granules. Carapace
with median row of spines, two gastric (posterior
one larger), one large cardiac, one small back-
ward-pointing intestinal, and a long acuminate
backward-projecting spine at distal end of first

240

FISH AND WILDLIFE SERVICE

Figure 217. — Anasimus latus Rathbun. Male in dorsal
view, legs of left side not shown, 10 mm. indicated.

abdominal segment; anterior gastric spine one of
transverse row of about five; branchial region
with three small spines or tubercles in triangular
arrangement. Three anterolateral spines, one he-
patic and two branchial above base of cheliped.
Rostrum short, medially carinate, broadly tri-
angular at base, ending in short, sharp, upturned
spine. Eyes large; prominent supraorbital spines
separated by depression, postorbital spines long,
exceeding eye in large specimens. Antenna short,
slightly exceeding rostrum, basal article with ter-
minal spine and a stout spine pointing downward
and forward in front of eye. Pterygostomian re-
gion with row of spines and spinules continued
to antennal segment including long spine at
angle of buccal cavity. Sternum of male coarsely
granulate.

Chelipeds of male more than twice length of
carapace, granulate; merus cylindrical; palm
swollen, shorter than fingers; fingers slender,
curved inward, gaping at base only, finely and
evenly toothed except for larger basal tooth on
dactyl. Female with chelipeds a little longer than
carapace but smaller than in male, fingers not
gaping. Walking legs long, slender, cylindrical,
roughened, except on dactyl, with numerous short,
stout, appressed spinules; propodi and dactyls
with double fringe of hair.

MARINE DECAPOD CRUSTACEANS OF THE CAROLENAS

Abdomen of male with six, female with five,
free segments; female with median tubercle on
third and fourth segments.

Measurements. — Carapace: male, length, 26
mm., width, 24 mm. Length of cheliped, 58 mm.,
of first walking leg, 106 mm.

Variations. — The adults are relatively broader
than the young whose rostrum and dorsal spines
are longer. The postorbital spines are very small,
pointing directly outward, and with little more
than a tubercle in specimens 9 mm. long or less.

Color. — Recently preserved specimens show
dark reddish or brown rings on the legs (Hol-
thuis, 1959).

Habitat. — This form has been taken from coarse
sand, coral, coral sand, and mud and shell bottom ;
26 to 88 fathoms.

Type locality. — Gulf of Mexico, east of Delta
of Mississippi River, lat. 29°14'30" N. long 88°
09'30" W.j 68 fathoms.

Known range. — Off Cape Lookout, N.C., to off
Tabasco, Mexico (Hildebrand, 1954) ; west of
Trinidad, and off Surinam (Holthuis, 1959).

Remarks. — Ovigerous females have been re-
ported from southern Florida and the northern
Gulf of Mexico in all seasons of the year, from
North Carolina in June (Rathbun, 1925, and U.S.
National Museum records), and Surinam from
April to August (Holthuis, 1959).

Genus Podochela Stimpson, 1860

Rathbun, 1925, p. 31.

KEY TO SPECIES IN THE CAROLINAS

a. Rostrum broad, rounded in front.

b. Dactyls of last three pairs of legs less than one-half
length of propodus ; pterygostomian region bearing a

broad, spinelike projection riisei (p. 241).

bb. Dactyls of last three pairs of legs one-half or
more length of propodus ; pterygostomian region bear-
ing a long thin lamina Sidney! (p. 242).

aa. Rostrum long, spiniform gracilipes (p. 243).

Podochela riisei Stimpson

Figures 218, 223G
Podochela riisei Stimpson, 1860a, p. 196, pi. 2, fig. 6. — Hay and
Shore, 1918, p. 453, pi. 37, fig. 9.— Rathbun, 1925, p. 33. text-
figs. 9a-b; pi. 11, figs. 1-2; pi. 208, fig. 2 (rev.).

Recognition characters. — Carapace pyriform,
depressed, widest near posterior margin, greatest
width about two-thirds length, dorsal region un-
even and with tufts of hairs. Rostrum broad,

241

Figure 218. — Podochela riisei Stimpson. Animal in dorsal
view, legs of left side not shown, 5 mm. indicated.

rounded in front, deeply excavated below for
antennules, carinate above and with a tuft of
curled hairs. Orbits rounded, margins thickened
and with a row of hairs. Eyestalks short and
stout, cornea oblique, dorsal emargination with
distal tubercle tufted. Basal article of antenna
with a high crest on each margin. Sternum of
male thrown into ridges radiating to bases of legs.

Chelipeds slender in both sexes, fingers in con-
tact throughout their length (stouter and slightly
agape proximally in adult males). First pair of
walking legs stouter than others, about three times
as long as carapace; upper surface of all legs with
regularly spaced tufts of stiff curled hairs.

Abdomen of male with six, female with five,
free segments.

Measurements. — Carapace : male, length, 21
mm., width, 16 mm.; female, length, 23 mm.,
width, 20 mm.

Variations. — The rostrum is variable in shape
and length. Margins of the basal antennal articles
are thick in old individuals but may be thin in
younger ones. Sternal segments of males usually
have rounded surfaces but are sometimes flattened.

Color. — Overall color light brown ; legs lighter,
grading to almost off white or pale yellow; chelae
and chelipeds nearly white to almost transparent;
carapace darker on lateral aspects of urogastric
and cardiac regions, as well as at posterolateral
portions of metabranchial regions. AYass (1955)
reported brick red specimens.

Habitat. — Has been taken from among hydroids
on pilings at Beaufort, NO, and in rocky areas
in northwestern Florida (Wass, 1955) ; shallow
water to 30 fathoms.

Type locality. — Island of St. Thomas, [West
Indies].

Known range. — North Carolina to Campeche,
Mexico; through West Indies to St. Thomas; Rio
de Janeiro and south of Pernambuco, Brazil;
Bermuda.

Remarks. — Ovigerous females have been taken
in North Carolina in September. They have been
taken in Florida from June to August and from
November to February (U.S. National Museum
records).

Podochela sidneyi Rathbun

Figures 219, 223H

Podochela sidneyi Rathbun, 1924, p. 1. — Rathbun, 1925, p. 39,
text-fig. 9c, pis. 12-13 (rev.).

Recognition characters. — Closely resembling
Podochela riisei. Rostrum narrower at base.
Pterygostomian region bearing a long thin lamina
either subtriangular or produced downward in a
lobe. Sternal segments flat with sharp cristate
margins.

Chelipeds of adult male less inflated than in
P. riisei, proximal gape narrower, teeth on cutting
edsres more numerous and uniform in size. Walk-

Fiqube 219.— Podochela sidneyi Rathbun. Animal in dor-
sal view, legs of left side not shown, 5 mm. indicated.

242

FISH AND WILDLIFE SERVICE

ing legs longer than in P. riisei; first pair of
walking legs 3 or more times as long as cara-
pace; dactyls of last three pairs less curved,
longer and relatively more slender than in P.
riisei; dactyl of second leg up to one-half length
of propodus, of third leg to two-thirds, and of
fourth leg to three-fourths length of propodus.

Abdomen of male with six, female with five,
free segments.

Measurements. — Carapace : male holotype,
length, 14 mm., width, 11 mm.

Habitat.— Shallow water to 102 fathoms.

Type locality.— OR Cape Hatteras, N.C., 49
fathoms.

Known range. — Off Cape Hatteras, N".C, to
Port Aransas, Tex. ; northwestern Cuba ; Yucatan
Channel.

Remarks. — Hildebrand (1954) reported the
carapace of this species as decorated with hy-
droids and ascidians.

Podochela gracilipes Stimpson

Figures 220, 2231

Podochela gracilipes Stimpson, 1871a, p. 126. — Hay and Shore,
1918, p. 454, pi. 37, fig. 6.— Rathbun, 1925, p. 47, text-fig. 12.
pi. 17 (rev.K

Recognition characters. — Carapace narrow, py-
rif orm, depressed ; constricted behind orbits ; with
rounded protuberance on cardiac region and two
smaller median protuberances on gastric regions.
Rostrum long, spiniform, hairy, unarmed. Ster-
num of males with thick blunt spine at base of
cheliped. Crests on basal article of antenna less
pronounced than in P. riisei, article long, narrow
posteriorly, with a diagonal ventral ridge merg-
ing with terminal spine distally.

Chelipeds in male stout, inflated, fingers widely
agape to near tip, large tooth near base of dactyl.
Chelipeds slender in female. Walking legs slender,
first pair three times length of carapace; dactyls
long, nearly straight, one-third length of prop-
odus; propodi of last three pairs thickened
distally ; dactyls slightly scythe-shaped, two-fifths
length of propodus on second pair, one-half
length on third, and two-thirds length of prop-
odus on fourth pair.

Abdomen of male with six, female with five,
free segments.

Measurements. — Carapace: male, length, 13
mm., width, 9 mm.; ovigerous females, length, 9
mm., width, 6 mm.

Figure 220. — Podochela gracilipes Stimpson. Animal in
dorsal view, legs of left side not shown, 5 mm. indi-
cated.

Habitat. — Eighteen to 120 fathoms.

Type localities. — West of Tortugas, off Pacific
and Carysfort Reefs, [Fla.], 36 to 60 fathoms.

Known range. — Off Cape Lookout, N.C., to
Gulf of Mexico ; Caribbean Sea to Columbia and
Barbados; Cabo Frio, Brazil.

Remarks. — Ovigerous females are known in
December from North Carolina.

Genus Metoporhaphis Stimpson, 1860

Rathbun, 1925, p. 19.

Metoporhaphis calcarata (Say)

Figures 221, 223J

Leptopcdia calcarata Say, 1818, p. 455.

Metoporhaphis calcaratus: Hay and Shore, 1918, p. 454, pi. 37,

fig. 5.

Metoporhaphis calcarata: Rathbun, 1925, p. 21, text-fig. 5,

pis. 6-7 (rev.).

Recognition characters. — Carapace triangular,
longer than broad, uneven, nodulose with each
nodule surmounted by a tubercle and this in turn
usually with a pencil of soft, hooked hairs.
Rostrum as long as or longer than carapace, sub-
cylindrical, tapering to a point, often armed with
four or five slender spines projecting outward al-
ternately from opposite sides of lower surface,
and with distal pair so close to tip as to give tip
bi- or tri-spinose appearance. Eyes protuberant,
peduncles terminating in superior spinule project-

MARESTE DECAPOD CRUSTACEANS OF THE CAROLENAS

243

Figueb 221. — Metoporhaplus calcarata (Say).- Animal in
dorsal view, legs of left side not shown, 10 mm. indi-
cated.

ing beyond cornea. Basal antennal article with
spine below at midpoint of length, another at
outer distal angle, and a spinule at end of next
two articles.

Chelipeds of moderate length, twisted, stout in
male and less than half as long as first walking
legs, margin of lower (really inner) surface
armed with sharp spines; merus with sharp ter-
minal spine ; carpus with two sharp dorsal spines,
one near each extremity of upper surface; hand
broad, inflated; fingers about as long as palm,
bent medially. Female with chelipeds feebler,
palm shorter, fingers longer and more gaping.
"Walking legs slender, articles cylindrical but
somewhat crooked; meri with one conspicuous
spine and two smaller spines at extremity;
dactyls longer than propodi, fringed with hair.

Male with six, female with five, free abdominal
segments.

Measurements. — Carapace: female, length (in-
cluding rostrum), 21 mm., width, 10 mm. Length
of rostrum, 11 mm.

Color. — Dirty gray to lemon yellow.

Habitat. — Often found among hydroids near
Morehead City, N.C., and also taken in dredges
in Bogue Sound nearby; shallow water to 49
fathoms.

Type locality. — Bay of Charleston, S.C.

Known range. — Off Cape Hatteras, N.C., to
Rio de Janeiro, Brazil.

Remarks. — Ovigerous females have been taken
off South Carolina in August, and in Florida in
March and August (Wass, 1955). Wass also noted

that this species can remain suspended in water
by "rhythmic waving of its long, setae-lined legs."

Genus Stenorynchus Lamarck, 1818

Rathbun, 1925, p. 13.
Stenorynchus seticornis (Herbst) . Arrow crab

Figures 222, 223K

Cancer seticornis Herbst, 1788, p. 229, pi. 16, fig. 91 (see Rath-
bun, 1925).

Stenorynchus Sagittarius: Hay and Shore, 1918, p. 455, pi. 37,
fig. 8.

Stenorynchus seticornis: Rathbun, 1925, p. 13, text-flg. 3,
pis. 2-3 (rev.).— Monod, 1956, p. 567, figs. 838-839.

Recognition characters. — Carapace smooth, tri-
angular, longer than broad, diminishing in width
to level of eyes and thence produced into a
slender, horizontal, flattened, laterally spinulifer-
ous rostrum varying from slightly longer to 2.5
times as long as carapace; rostral tip acuminate.
Orbits not defined; post orbital spine small, oc-
casionally bifid. Eyes short, not retractile. Basal
article of antenna slender, with strong spine at
middle directed downward and forward.

Legs extremely long and slender, composed of
cylindrical articles, finely spinulose and bearing
in addition two rows of spines on merus, two or
three spines on carpus, and several terminal spines
on these articles. Chelipeds slender, cylindrical;
hand weak; palm of male cheliped from 2.5 to

Figure 222. — Stenorynchus seticornis (Herbst). Animal
in dorsal view, legs of left side not shown, 30 mm.
indicated.

244

FISH AND WILDLIFE SERVICE

Figure 223. — Subfamily Inaehinae, tips of right first pleopods of males; A, Anomalothir furcillatus (Stimpson),
abdominal view; B, Euprognatha rastellifera marthac Ratbbun, sternal view; C, Batrachonotus fragosus Stimp-
son, sternal view; D, Collodes trispinosus Stimpson, sternal view; E, Pyromaia cuspidata Stimpson, sternal view;
F, Anasimus latus Rathbun, sternal view; G, Podochela riisei Stimpson, sternal view; H, Podochela sidneyi
Rathbun, sternal view; I, Podochela gracilipes Stimpson, sternal view; J, Metoporhaphis calcarata (Say),
sternal view ; K, Stenorynchus setico'rnis ( Herbst) , sternal view ; 0.33 mm. indicated.

4 times as long as dactyl. First pair of walking
legs from 8 to 9 times as long as postrostral por-
tion of carapace; second, third, and fourth legs
successively shorter; dactyls on each pair longer
than propodi.

Abdomen in male with six, female with five,
free segments.

Measurements. — Carapace : male, length includ-
ing rostrum, 57 mm.; width, 13 mm. Length of
rostrum, 41 mm.

Variations. — There is great variation in length
of rostrum, relative length of palm and fingers,
and length of legs. In old individuals the rostrum,
chelipeds, and legs are pubescent.

Color. — Body ground color gray, banded dor-
sally with stripes of light and dark brown or
black converging anteriorly as a nested series of
inverted V's; one dark pair of stripes continuing
united on dorsal side and another more lateral

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-4)49 O— 65 17

pair of like color on ventral side of rostrum.
Legs reddish brown, joints darker; fingers of
chelipeds bluish purple.

Rathbun (1925) summarized other color ob-
servations. The general pattern is as above, with
ground color creamy white, buff, or light orange
vermilion; stripes white, chestnut, brown, or
black; legs reddish with bright red spots at
joints; chelae purple or mauve; spines on legs
and rostrum orange or red ; eyes maroon.

Habitat. — This form has been dredged or
trawled from a variety of bottoms — rock, coral
rock, pebbles, sand, or sand mixed with broken
shell; also, it has been taken from wharf pilings
and rock jetties. Near surface to 814 fathoms.

Type locality. — Guadeloupe (Holthuis, 1959).

Known range. — North Carolina to Rio de
Janeiro, Brazil ; Bermuda ; eastern Atlantic from
Madeira and Canary Islands to Angola.

245

Remarks. — Though this species has a tremen-
dous recorded range in depth, it is usually found
well inside the 100-fathom mark. On September
6, 1953, an ovigerous female was collected from
wharf pilings in Bogue Sound near Bogue Inlet,
N.C.

Otherwise, ovigerous females are known or have
been reported in the western Atlantic from Febru-
ary in the Gulf of Darien, throughout spring and
summer in North and Middle America, and north-
ern South America, to November off the Amazon
River (U.S. National Museum records; Hilde-
brand, 1954; Holthuis, 1959; Rathbun, 1925).

Subfamily Ophthalmiinae

Orbit consisting, if complete, of a supraocular
eave and a postocular spine; intercalated spine
lacking . . . [but] . . . longer spinous outgrowths
on supraocular eave and on postocular spine for
most part present. Shape of body elongate, some-
what truncate in front, often provided behind
with a median spine or outgrowth (Balss, 1929).

KEY TO GENERA OF OPHTHALMIINAE IN THE
CAROLINAS

Modified after Garth (1958)

a. Eyes furnished with projecting and tubular commenc-
ing orbits puho (p. 246).

aa. Orbit completely unprotected below; eyes protected
above by a lamellate projection consisting of supraocu-
lar eave and an outgrowth of hepatic region

Tyche (p. 247).

Genus Pitho Bell, 1835

Garth, 1958, p. 162.
Pitho Iherminieri (Schramm)

Figures 224, 233A

Othonia Iherminieri Schramm, in Desbonne and Schramm 1867
p. 20.

Pitho Iherminieri: Hay and Shore, 1918, p. 459, pi. 38. fig 8 —
Rathbun. 1925, p. 362. text-flg. 117b, pi. 128, figs 1-2- pi 129
figs. 1-2 ; pi. 252, fig. 2 (rev.).

Recognition characters.— Carapace as broad as
long in adult males, longer than broad in other
individuals, narrow behind in males, broader in
females, roughened with tubercles of different
sizes, and adorned with scattered hooked hairs.
Frontal teeth forming rostrum more advanced
i orbital angles. Anterolateral margins armed
five strong teeth, exclusive of postorbitai
tooth; first tooth largest, second and third sub-

Figure 224. — Pitho Iherminieri (Schramm). Male in
dorsal view, legs of left side not shown, 5 mm.
indicated.

equal, fourth and fifth much smaller, second oc-
casionally bilobed. Orbits small, tubular, deep.
Antenna short, with stiff hairs on borders; basal
article lamellate, forming floor of orbit; second
article flat, short, and broad; third article smaller,
flattened.

Chelipeds of adult male from 1.5 times to
nearly twice length of body; merus subcylindri-
cal; carpus and hand more or less compressed
and distinctly angled along margins; fingers of
adult male hollowed into spoon shape, touching
only at extremity. In female and young male,
fingers short and weak, evenly dentate, with mar-
gins in contact.

Abdomen of both sexes with seven free seg-
ments.

Measurements. — Carapace: male, length, 26
mm., width, 24 mm.; female, length, 18 mm.,
width, 17 mm.

Variations. — In females and young males the
carapace is more tuberculate than in old males,
the lateral teeth are sharper, and the last two
teeth are more prominent than in mature males.

Color. — Dirty brownish yellow (Desbonne in
Rathbun, 1925).

Habitat. — This species has been found on a
variety of bottoms including mud, sand, shell-
sand, shell, rock and coral, and grass (Rathbun,

246

FISH AND WILDLIFE SERVICE

1925). One-half to 28 fathoms, rarely to 120
fathoms.

Type locality. — Guadeloupe, in cavities of the
keys.

Known range. — Off Beaufort Inlet, N.C., to
west Florida; Vera Cruz, Mexico; West Indies
to Islet of Sao Sebastiao, Sao Paulo, Brazil.

Remarks. — Ovigerous females are known from
May to November in the Bahamas and Florida,
and in December from Brazil (Rathbun, 1925,
and U.S. National Museum records) .

Genus Tyche Bell, 1835

Garth, 1958, p. 172.
Tyche emarginata White

Figures 225, 226, 233B

Tyche emarginata White, 1847a, p. 206. — nay and Shore, 1918,
p. 461, pi. 39, fig. 4.— Rathbun, 1925, p. 508, pi. 272; pi. 273,
figs. 7-12 (rev.).— Garth, 1946, pp. 406-408, text-fig. 1.

Recognition characters. — Carapace oblong-oval,
flattened, with lamellate expansions in front
covering ocular peduncles, and another prolonged
and bilobed behind, stout hooked hairs on rostrum
and prominent elevations. Front wide, with four
long horns, lateral horns forming anterior angles
of orbit, divergent, longer and more elevated than
median rostral horns. Ocular peduncles entirely
uncovered below. Gastric region swollen, with

Figure 225. — Tyche emarginata White. Male in dorsal
view, legs of left side not shown, 5 mm. indicated.

Figure 226. — Tyche emarginata White. Left
outer ruaxilliped (after Garth, 1946).

three low tubercles, two anterior, and a third
posterior and median; cardiac region depressed,
with three small tubercles. Lateral borders
straight and nearly parallel at hepatic regions,
rounded at branchial regions. Dorsal surface of
hepatic region concave; branchial region with
large tubercle on anterior lobe, and a prominent
tuberculate crest above lateral margin. Exopodite
of third maxilliped with basal protuberance re-
curving to cover base of ischium, merus inserting
deeply into outer distal portion of ischium by
similar but less developed process, inner margin
of ischium strongly dentate.

Chelipeds of male more than twice length of
post orbital part of carapace; palms somewhat
dilated and compressed; fingers gaping at base,
dentate throughout length. Walking legs orna-
mented with stout hooked hairs; dactyls spinulous
on middle third, spinules increasing in size distally.

Abdomen of both sexes with seven free seg-
ments.

Measurements.— Carapace : female, length, 35
mm. ; width, 21 mm.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

247

Color. — Generally yellowish gray; carapace
greenish above, with two triangular white spots;
blackish above base of legs (various authors).

Habitat. — The species has been reported from
rocky or coarse shell bottoms (Rathbun, 1925) ;
a few feet to 20 fathoms.

Type locality. — West Indies.

Known range. — Off Beaufort Inlet, N.C. ;
through Bahamas to west coast of Florida ; Cape
Sao Roque, Rio Grande do Norte, Brazil.

Remarks. — Garth (1946) gave a detailed com-
parison of this species with its Pacific counter-
part, T. laniellifrons.

Subfamily Acanthonychinae

Eyes without true orbits; eyestalks very short
or sometimes obsolescent, either concealed beneath
an anteriorly produced supraocular spine, or sunk
in sides of a huge beaklike rostrum ; a postocular
spine or process sometimes present, but not
excavated for reception of retracted eye. Basal
antennal article elongate but truncate-triangular.
External maxillipeds with merus as broad as
ischium. Dactyls of walking legs prehensile or
subchelate; last three pairs of legs often dis-
proportionately short compared with [first] pair
(Alcock, 1895). Postocular spine not cupped (ex-
cept in Sphenocarcinus) ; rostrum either simple
or two-spined; palp on third maxilliped arising
from anterointernal angle of merus (Rathbun,
1925). First pleopod medium stout, apex most
varying (hammer-shaped; divided into three or
four lobes; etc.) ; second pleopod short (Stephen-
sen,- 1945).

KEY TO GENERA OF ACANTHONYCHINAE IN THE
CAROLINAS

a. Rostrum double ; seven free abdominal segments In
both sexes Sphenocarcinus (p. 248).

aa. Rostrum single or secondarily bifurcate ; six free
abdominal segments in male, five in female

Epialtus (p. 249).

Genus Sphenocarcinus Milne Edwards, 1878

Garth, 1958, p. 217.
Sphenocarcinus corrosus Milne Edwards

Figures 227, 233C

Sphenocarcinus corrosus Milne Edwards, 1875, pi. 17, figs.
5-5c— Hay and Shore, 1918, p. 460, pi. 39, fig. 1.— iRathbun,
1925, p. 187, text-fig. 73, pi. 62 ; pi. 223, figs. 3-5 (rev.).

Recognition characters. — Carapace subpentago-
nal, broad behind, anterolateral margin concave,

Figure 227. — Sphenocarcinus corrosus Milne Edwards.
Male in dorsal view, legs of left side not shown, 2 mm.
indicated.

posterolateral margin convex. Dorsal surface
deeply channeled, leaving symmetrical, coarsely
punctuate, or eroded elevations in regular pattern
as follows: a longitudinally placed, trefoil-shaped
gastric, a transversely placed cardiac with two
deep posterior indentations, a transversely elon-
gate intestinal, paired laterals extending from
near lateral angles to near eyes, and paired small
postocular and larger supraocular elevations;
margins of all elevations sharply defined with sur-
face finely eroded. Rostrum usually longer than
carapace, formed of two pointed horns contingu-
ous to near tips, slightly divergent in old indi-
viduals. Eye deeply sunk between two low smooth
excrescences. Basal antennal article truncate, an-
tennal flagelluni hidden beneath rostrum. Epi-
stome long, narrow.

248

FISH AND WILDLIFE SERVICE

Chelipeds weak; first pair of walking legs
longer than others and exceeding length of cheli-
peds by more than length of dactyl.

Abdomen in both sexes with seven distinct
segments.

Measurements. — Carapace: male, length, 13
mm., width, 7 mm.; ovigerous female, length, 23
mm., width, 11 mm.

Variations. — Divergence of the rostral horns
varies individually. In some specimens the horns
are contiguous nearly to the tip, in others the
horns may be divergent for half their length, and
in still others there is no evidence at all of
bifurcation.

Color. — Orange- red.

Habitat. — Ninety to 148 fathoms.

Type locality. — Off Barbados, 100 fathoms.

Known range. — Off Cape Lookout, N.C., to
Barbados.

Remarks. — Ovigerous females have been re-
ported from North Carolina in April (Rathbun,
1925).

Genus Epialtus H. Milne Edwards, 1834

Garth, 1958, p. 227.

Epialtus dilatatus Milne Edwards

Figures 228, 233D

Epialtus dilatatus Milne Edwards, 1878, p. 140, pi. 27, figs.
4-4b — Rathbun, 1925, p. 153, text-fig. 53j, pi. 45, fig. 2 (rev.).

Recognition characters. — Small species. Cara-
pace broad, subpentagonal, almost smooth, with
hepatic and branchial projections more or less
laminate. Rostrum broad, somewhat triangular,
short, bilobed at tip, slightly depressed on median
line dorsally with depression continued ventrally
and limited by two crests uniting posteriorly in
an acute angle. Eyes small; preorbital angles
scarcely marked; postorbital teeth minute. Basal
article of antenna triangular, movable part con-
cealed beneath rostrum.

Chelipeds moderate in size; carpus with four
longitudinal crests; hand slightly enlarged dis-
tally, upper margin blunt, defined by depression
on either side; fingers short and stout. Walking
legs with slight tuft of hair on lower margin of
propodi.

Abdomen of male with six, female with five,
free segments.

Figube 228. — Epialtus dilatatus Milne Edwards. Male
in dorsal view, legs of left side not shown, 3 mm.
indicated.

Measurements. — Carapace: male, length, 17
mm., width, 13 mm.; female, length, 10 mm.,
width, 8 mm.

Variations. — Members of the genus Epialtus
are variable in a number of respects. The hepatic
expansion may vary in shape and the rostrum may
vary from triangular to suboblong in shape.

Rathbun (1925) recognized from southwestern
Florida an elongate form which has a longer ros-
trum and slightly different lateral expansions
than the typical form.

Habitat. — The species has been reported from
shell reefs and coarse coral sand, and the elongate
form has been found on sandy-grassy bottoms as
well. Two and one-half to 12 fathoms.

Type locality. — St. Thomas.

Known range. — Off Beaufort Inlet and New
River, N.C. ; southwest Florida; Yucatan; Ba-
hamas to St. Thomas.

Remarks. — Rathbun (1925) reported ovigerous
females from Florida in April. They are known
from North Carolina in June, and in Florida
through the summer. Other records are Brazil in
September, and Puerto Rico in November (U.S.
National Museum records).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

249

Subfamily Pisinae

Eyes with commencing orbits, eye retractile into
sometimes large, blunt, usually isolated, cupped
postocular tooth or lobe, but never to such extent
as to conceal completely cornea from dorsal view ;
usually a prominent supraocular eave with an-
terior angle sometimes produced forward as a
spine; eyestalks short. Basal antennal article
broad, at least at base, anterior angle generally
produced to form a tooth or spine. Merus of ex-
ternal maxilliped broader than ischium owing to
expansion of anteroexternal angle, and carrying
palp at anterointernal angle. Rostrum [except in
Neododea among New World forms] two-spined;
legs often very long (Alcock, 1895). First pleo-
pod medium stout to slender, usually apically
somewhat tapering, but apex extremely varying
(blunt, acute, filiform, straight, geniculate, etc.) ;
second pleopod short (Stephensen, 1945).

KEY TO GENERA OF PISINAE IN THE CAROLINAS

Modified after Garth (1958)

a. Intercalated orbital spine present Nibilfo (p. 251).

aa. Intercalated orbital spine absent.

b. Supraocular eave and postocular process not closely

approximated Pclia (p. 250).

bb. Supraocular eave and postocular process closely
approximated Libinia (p. 251).

Genus Pelia Bell, 1835

Garth, 1958, p. 268.
Pelia mutica (Gibbes)

Figures 229, 233E

Pisa mutica Gibbes, 1850, p. 171.

Pelia mutica: Hay and Shore, 1918, p. 455, pi. 38, fig. 7.—
Rathbun, 1925, p. 278, text -fig. 94, pi. 98, figs. 2-3 (rer.).

Recognition characters. — Small species. Cara-
pace pyriform, greatest width approximately two-
thirds greatest length, swollen, devoid of tuber-
cles, covered with sparse pubescence, gastric and
cardiac regions elevated. Rostrum well developed,
two-fifths as long as remainder of carapace,
formed of two more or less distally divergent
horns with outer margins often parallel, a furrow
on basal portion. Eyes retractile. Basal antennal
article long, slender, forming incomplete floor to
orbit and jutting out beyond orbital margin, usu-
ally with small tootb or spine at anteroexternal
angle: antennal flagellum greatly developed.

250

Figure 229. — Pclia mutica (Gibbes). Animal in dorsal
view, legs of right side not shown, 3 mm. indicated.

Chelipeds of mature male as long as first walk-
ing legs but stouter and almost bare, weaker in
females and young males; upper and inner margin
of merus dentate; carpus with a longitudinal den-
ticulate ridge; upper and lower margins of hand
slightly arcuate; basal half of fingers widely
agape, with denticulate margins on occludent por-
tions and broad basal tooth of dactyl; fingers
weaker and not agape in females and young
males. Walking legs with marginal rows of stiff
setae, meri much compressed, dactyls strongly
curved.

Abdomen of both sexes with seven free seg-
ments.

Measurements. — Carapace : male, length, 13
mm., width, 9 mm.; ovigerous females, length.
5-10 mm. (Wass, 1955).

Color. — Bright red in patches on carapace and
in bands on legs, spots of light red on chelipeds
(Rathbun, 1925).

Habitat. — This species has been found on
gravelly and shelly bottoms of bays and sounds,
among hydroids, ascidians, and sponges on wharf
piles, and also on shelly reefs off Beaufort Inlet.

FISH AND WILDLIFE SERVICE

N.C. (Pearse and Williams, 1951). Individuals
are often so covered with sponge that they are
difficult to recognize. Gray (1961) reported the
species from Chaetopterus tubes. Low water to 28
fathoms.

Type locality. — Charleston Harbor, off White
Point Battery, S.C.

Known range.- — Buzzards Bay and Vineyard
Sound, Mass., to west coast of Florida; Cuba,
Puerto Rico, and St. Thomas, West Indies.

Remarks. — Ovigerous females are known from
February to July in Florida, through the summer
in the Carolinas, and in Massachusetts in July
(Rathbun, 1925; U.S. National Museum records).

Genus Nibilia Milne Edwards, 1878

Rathbun, 1925, p. 289.
Nibilia antilocapra (Stimpson)

Figures 230, 233F

Pisa antilocapra Stimpson, 1871a, p. 110.

Nibilia antilocapra: Rathbun, 1925, p. 290, text-fig. 97, pis. 102,
103, and 239 (rev.).

Recognition characters. — Carapace pyriform,
conspicuously spinose, much swollen, longer than
wide; gastric and cardiac regions with about 18
spines of moderate size and smaller ones inter-
spersed, largest spines surmounting summit of
regions and somewhat surrounded by circle of
smaller spines; other regions also well spined.

Figure 230. — Nibilia antilocapra (Stimpson). Male in
dorsal view, legs of left side not shown, 10 mm.
indicated.

Rostrum horizontal, undivided at base but mod-
erately bifurcate for greater part of length, horns
varying from three-fifths to four-fifths total
length of rostrum. Preorbital spine ascending,
slightly curved, not so advanced as base of horns;
behind this a small spine on supraocular eave and
a triangular (intercalated) spine or tooth on su-
praocular border ; postocular cup terminating in a
spine. Basal antennal article with a short spine
just outside posterior end, behind this a tubercle
in line with prominent spine at angle of buccal
cavity. Maxilliped and sternum smooth.

Chelipeds of adult male longer and stouter than
walking legs ; merus and carpus rough with spines
above and below; chelae almost cylindrical; hand
nearly as long as merus, nearly smooth, a few
spines near articulation with carpus; fingers
agape for half of length in old males, with a well-
developed tooth on dactyl in gaping part. Walk-
ing legs long, slender; merus and carpus with a
few spines longitudinally arranged ; dactyls long,
stout, unarmed.

Measurements. — Carapace: large male, length,
120 mm., width, 82 mm.; female, approximate
length, 60 mm., width, 43 mm.

Variations. — The young and half-grown are
covered with short hair, but the old are nearly
bare except for hairy dactyls on the walking legs.
Habitat. — The species has been reported from
gray and coarse sand, broken-shell, and coral bot-
toms (Rathbun, 1925) ; 39 to 140 fathoms.

Type localities. — Florida, off Carysfort Reef,
52 and 60 fathoms; and off Alligator Reef, 118
fathoms.

Known range. — Off Cape Hatteras, N.C, to
Gulf of Mexico just east of Mississippi River
Delta and Gulf of Campeche; Windward Islands,
West Indies.

Remarks. — Ovigerous females have been re-
ported from St. Vincent in February and from
Barbados in March (Rathbun, 1925).

Genus Libinia Leach, 1815

Garth, 1958, p. 322.

KEY TO SPECIES IN THE CAROLINAS

a. Median line of carapace with about nine spines

cmarginata (p. 252).
aa. Median line of carapace with about six spines

ditbia (p. 252).

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

251

Libinia emarginata Leach. Spider crab

Figures 231, 233H

Libinia emarginata Leach, 1815, p. 130, pi. 108. — Hay and
Shore, 1918, p. 456, pi. 38, fig. 6. — Rathbun, 1925, p. 311, text-
figs. 103-104 ; pis. 110-113 (rev.).

Recognition characters. — Carapace orbicular,
about one-sixth longer than wide, spinose and
tuberculate, with dense covering of short hairs.
Larger spines arranged as follows: median row
of about nine extending from near base of ros-
trum to posterior border consisting of four gas-
tric, one genital, two cardiac, and two intestinal ;
lateral marginal spines five on each side; two
subhepatic spines; two or four spines above pos-
terior margin, aside from median spine, and about
four dorsal branchial spines; spiniform tuber-
cles scattered about among larger spines. Gastric
region marked off by a deep groove. Rostrum
slightly depressed, emarginate or bifid at tip; a
median groove between eyes. Orbits with promi-
nent preorbital spine, two spines beneath on basal
article of antenna; one fissure above and one be-
neath.

Chelipeds equal, larger in male; hands granu-
late ; fingers smooth, evenly denticulate, and about
half as long as hand. Walking legs long, hairy,
unarmed, often unequal and asymmetrical (result,
perhaps, of injury and subsequent regeneration).

Measurements. — Carapace: male, length, 103
mm., width including spine, 94 mm.; female,
length, 62 mm., width, 58 mm.

l'ii. i be 231. — Libinia emarginata Leach. Male in dorsal
view, legs <>f left side not shown, 20 nun. Indicated.

Variations. — The number of median spines in
the gastric region is subject to some variation in
size and number.

Color. — A brownish or dirty yellow.

Habitat. — Found on almost any kind of bot-
tom ; shore to 27, occasionally 68, fathoms.

Type locality. — Unknown.

Known range. — Windsor, Nova Scotia, to west-
ern Gulf of Mexico.

Remarks. — Hildebrand (1954) reported this
species as the most common large spider crab in
the western Gulf of Mexico. It was most common
in July, at which time ovigerous females were ob-
served. Another ovigerous female was taken in
February. (Elsewhere ovigerous females are
known from New Jersey in August (U.S. Na-
tional Museum records).) Hildebrand also ob-
served juveniles riding in the bell of scyphozoan
Stomolophus meleagris, a habit noted by others
for the young of L. dubia.

The young of L. emarginata and L. dubia are
difficult to distinguish. Wass (1955) pointed out
useful distinguishing marks. "The rostrum of
L. dubkt is much longer, forming a V; the cara-
pace is not so wide, and there is but one spine on
the intestinal region . . . whereas L. emarginata
has two.''

Gray (1957) compared gill area in this sluggish
species with that of other common littoral crabs in
the Carolinas and found that it had the smallest
gill area per gram body weight of any studied.

Libinia dubia H. Milne Edwards. Spider crab

Figures 232, 2330

Libinia dubia H. Milne Edwards, 1834, p. 300, pi. 146i«, fig. 2. —
Hay and Shore, 1918, p. 456, pi. 38, fig. 5.— Rathbun, 1925, p. 313,
text-figs. 105-106; pis. 114-115; pi. 122, fig. 1 (rev.).

Recognition characters. — Similar in general
characters to L. emarginata but with more pyri-
f orm carapace and fewer spines ; median row with
but six spines, two gastric, one genital, two car-
diac, and one intestinal; preorbital, subhepatic,
and lateral spines stronger than in L. emarginata,
but spiniform tubercles few or wanting altogether.
Rostrum slightly longer and more definitely bifid
than in L. emarginata. Anterolateral angle of
buccal frame armed with a spine.

Measurements.— Carapace : male, length, 102
mm.; width including spines, 82 mm. Most indi-
viduals smaller.

252

FISH AND WILDLIFE SERVICE

Variations. — Dorsal spines and tubercles varia-
ble in length.

Habitat.— Found on almost all types of bottom
in the ocean and the saltier sounds. Occasionally,
large individuals are found on Bird Shoal near
Beaufort, N.C., in pools left by falling tide; fre-
quently specimens are brought up in otter trawls.
Immature individuals are often completely over-
grown with sponges, hydroids, or ascidians, but
the larger ones are usually almost clean. Near
shore to 25 fathoms.

Type locality. — Cotes des Etats-Unis.

Known range. — Cape Cod, Mass., to southern
Texas ; Bahamas and Cuba.

Remarks. — This species has a geologic record
extending from the upper Miocene of Virginia
(Rathbun, 1935) through the Pleistocene of New

Figure 232. — Libinia dubia H. Milne Edwards. Male
in dorsal view, legs of left side not shown, 10 mm.
indicated.

Figure 233. — Subfamilies Ophthalmiinae, Aeanthonychinae, and Pisinae, tips of right first pleopods of males ;
A, Pitho Iherminicri (Schramm), abdominal view; B, Tyche emarginata White, lateral view; C, Sphenocarcinus
corrosus Milne Edwards, sternal view ; D, Epialtus dilatatus Milne Edwards, sternal view ; E, Pelia mutica
(Gibbes), sternal view; F, Nibilia antilocapra (Stimpson), abdominal view; G, Libinia dubia H. Milne Edwards,
lateral view ; H, Libinia emarginata Leach, lateral view ; 0.33 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

253

Jersey (Rathbun, 1935) and Maryland (Easton,
1940).

Ovigerous females are known to occur in spring
in North Carolina.

Pearse (1929), studying the survival rates of
various estuarine crabs in dilutions of sea water
and in air, found L. dubia least able to survive
desiccation and dilutions of sea water. Ayers
(1938), in a study of the relationship of habitat
to oxygen consumption among certain estuarine
crabs, found that L. dubia lives much of the year
in .relatively deep [estuarine] water where there is
low oxygen content, sometimes very little. The
species is correspondingly sluggish and slow. Gray
(1957) showed that gill area per gram of weight
in this species is small.

A peculiar association of this species with the
jellyfish Stomolophus meleagris has been reported.
The crabs have been found in the subumbrellar
space and on occasion small specimens have been
taken from the genital pits. Corrington (1927)
found medusae with crabs between Sullivans Is-
land and Isle of Palms, S.C., in May, and Outsell
(1928) found the association in the vicinity of
Cape Lookout, N.C., in summer and fall. The
crabs were found in adult jellyfish and varied in
length from 3 to 37 mm.

Pearse (1952b) reported Octolasmis lowei
(=mt/Neri) on the gills and mouth parts, and
Chelonibia patula on the carapace of L. dubia in
Texas.

Subfamily Mithracinae

Carapace broadened anteriorly by outstanding,
often tubular, orbits; orbits formed (1) by an
arched supraocular hood, or semitubular horn, (2)
by a hollowed postocular process, and (3) by a
remarkable broadening, or by a prolongation, of
anterior part of basal antennal article, affording
complete concealment to retracted eye. Rostrum
often more or less deflexed (Alcock, 1895). First
pleopod like that in Pisinae; second pleopod short
( Stephensen, 1915).

KEY TO GENERA OF MITHRACINAE IN THE
CAROUNAS

Modified after Garth (1958)

tercalated orbital spine present (between supraor-
bital and postorbital spine) ; <>rl>its projecting sorne-
>nd general outline of carapace, but not
tubular.

254

b. Rostrum small ; carapace ovate, usually broader
than long Mithrax (p. 254).

bb. Rostrum large, usually with two strong horns ;
carapace broadly pyriform ; basal antennal article
armed with a prominent spine at anteroexternal

angle Microphrys (p. 259).

aa. Intercalated orbital spine absent ; orbits tubular.

b. Lateral margin of carapace armed with series of
strong spines ; basal antennal article very broad

Strnocionops (p. 260).

bb. Lateral margin of carapace not armed with series
of strong spines, but with a spine, usually strong, at
lateral angle of carapace Macrocoeloma (p. 263).

Genus Mithrax Desmarest, 1823

Garth, 1958, p. 352.

KEY TO SPECIES IN THE CAROLINAS

(Modified from Garth, 1958, and Rathbun, 1925)
a. Carapace roughened to greater or lesser extent by
tubercles or spinules, branchial grooves wanting ; inter-
mediate orbital teeth conspicuous, pointed, or sub-
truncate (Subgenus Mithrax).

b. Hand armed above with spines or spinules.

e. Two spines only on basal (fused) article of an-
tenna spinosissimus *(p. 254).

cc. Three spines on basal (fused) article of antenna;
carapace paved with flattened granules, concealed

by short hair verrucosus (young) (p. 255).

bb. Hand not armed above with spines or spinules.
c. Carapace paved with close-set, tessellated gran-
ules verrucosus (p. 255).

cc. Carapace not paved with close-set, tessellated
granules,
d. Gastric region without definite transverse row

of five tubercles hispidus (p. 256).

dd. A transverse row of five tubercles across gas-
tric region plcuracanthus (p. 257).

aa. Carapace smooth and bearing oblique branchial
grooves, either strongly or weakly indicated ; inter-
mediate orbital teeth inconspicuous, tuberculiform

(Subgenus Mithraculus).
Carapace broader than long ; anterolateral margins cut
into spines, or angular lobes, or spines and lobes ; four
anterolateral protuberances behind orbit

forceps (p. 258).

Mithrax (Mithrax) spinosissimus (Lamarck)

Figures 234, 245A

Maia spinosissima Lamarck, 1818, p. 241.

Mithrax spinosissimus: Rathbun, 1925, p. 383, pi. 135 (rev.L

Recognition characters. — Large. Carapace
nearly naked, subcircular, approximately as broad
as long; surface rough with short spines, those in
center blunt, elsewhere sharp; cervical suture
deep; hepatic and cardiac regions distinctly de-
limited. Rostral horns narrow, obliquely truncate
and granulate at extremity, separated by a U-

FISH AND WILDLIFE SERVICE

Figure 234. — Mithrax (Mithrax) spinosissimus (La-
marck). Male in dorsal view, legs of left side not
shown, 30 mm. indicated.

shaped notch of equal length and breadth; two
stout spines at base of horns and two more behind
these but farther apart; preorbital spine stouter,
truncate, and less advanced than rostrum. Orbital
border with three small teeth exclusive of post-
orbital spine; suborbital margin with one acute
spine outside antennal segment and lateral to this
a larger truncate spine. Antennal segment with
an outer small acute spine and an inner spine more
advanced than rostrum bearing a small secondary
lateral spine near end. Lateral margin with six
spines, first two double, last and smallest one on
posterolateral margin. Other spines present on
suborbital, subhepatic, subbranchial, pterygosto-
mian regions, and at angle of buccal cavity.

Chelipeds of adult male massive, longer than
walking legs; merus armed with eight or nine
stout spines on outer margin, others irregularly
placed; carpus armed with unequal spines, about
five on inner margin; hand deep, compressed,
armed above with a more or less double row of
spines and on inner surface with two to four
spines proximally; fingers curved leaving wide
gape, strong tooth near middle of dactyl, tips
spooned with edges crenate preceded by a few
low tubercles. Adult female with chelipeds no
longer and not much stouter than first pair of
walking legs; hand tapering somewhat distally;

fingers narrowly gaping with numerous denticles
on cutting edges. Walking legs of both sexes spi-
nose and coarsely hairy; propodi elongate and
compressed.

Abdomen of male with seven free segments, fe-
male with six.

Measurements. — This is the largest species of
Mithrax. Carapace : male, length, 170 mm., width,
184 mm. ; female, length, 77 mm., width, 80 mm.

Variations. — In old males, spines on the cheli-
peds tend to become blunt and tuberculiform. In
medium-sized individuals, the carapace is rela-
tively longer than in the old, spines are sharper,
rostral horns curve inward at the sharp tips, the
carapace is covered with short hair, chelipeds of
both sexes are small, and the gape extends only
half the length of the fingers. In young indi-
viduals, the spines are even more accentuated,
rostral horns are one-fifth as long as the carapace,
there are two spines on the suborbital margin out-
side the antennal segment, chelipeds are no longer
or stouter than the first walking legs, and gape of
the fingers is less than in older individuals.

Color. — Bright carmine; vinous red with yel-
lowish tints; or thorax dark red; walking legs
brick red and chelipeds rose red with yellow
fingers (various authors including Rathbun,
1925).

Habitat. — The species is often found among
rocks. The carapace is often covered with en-
crusting organisms ; shallow water to 98 fathoms.

Type locality. — Ile-de-France. Locality errone-
ous.

Known range. — Either North Carolina or South
Carolina (?) through Florida Keys and West
Indies to Guadeloupe.

Remarks. — Ovigerous females have been re-
ported in May and June from Cuba (Rathbun,
1925).

Mithrax (Mithrax) verrucosus H\ Milne Edwards

Figures 235, 245B

Mithrax verrucosus H. Milne Edwards, 1832, cl. 7, pi. 4 (col.)
[+ unpaginated description]. — Rathbun, 1925, p. 400, pi. 144

(rev.).

Recognition characters. — Mature males, large-
to medium-sized. Carapace covered with flattened,
closely crowded granules, nearly naked, granules
covered with small pits, cervical suture deep;
branchial region with a few dorsal spines on outer
part, front and orbit with truncate spines. Rostral

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

255

Figtjbe 235. — Mithrax {Mithrax) verrucosus H. Milne
Edwards. Male in dorsal view, legs of left side not
shown, 20 mm. indicated.

horns short, separated by a deep notch. Preorbital
spine directed somewhat outward, four other
spines on orbital margin aside from three occur-
ring on broad basal antennal article. Anterolat-
eral margin with eight spines, first six in pairs,
anterior spines of each pair smaller, spines in first
two pairs more or less united at base; a single
posterolateral spine, and below lateral margin a
row of about nine spines.

Chelipeds stout ; outer margin of merus with six
sharp spines, approximately six spines on upper
surface; inner margin of whole cheliped armed
with blunt spines or lobes, one on ischium, four on
merus, two or three on carpus ; carpus with dorsal
surface smooth or slightly tuberculate proximally ;
palm unarmed, elongate, somewhat swollen, fin-
gers gaping with a large tooth near middle of
dactyl, edges of spoon-shaped tips slightly crenu-
late, two bunches of hair inside spoon. Walking
legs covered with coarse hair, meri and carpi
spiny.

Measurements. — Carapace: male, length, 51
mm. ; width, 65 mm.

Variations. — Females, young, and most imma-
ture males differ from mature males in that the
carapace is covered densely with hair. Rostral
horns of females and immature males are shorter
and farther apart, but horns of the young are
sharper. Spines on the inner margin of the cheli-

peds are sharper, the carpus is more or less spiny
dorsally, and the palm is spinulous and hairy
above proximally. The degree of spination on the
chelipeds also varies individually.

Color. — Dark red; color largely concealed by
hairiness, carapace dark dull red, pincers olive
above and lighter olive below, tips claret, teeth
white, underparts maroon flecked with white and
yellow (various authors and Rathbun, 1925).

Habitat. — This species lives near shore among
rocks, where it hides in holes. It is nocturnal, and
has been caught with the aid of a light while feed-
ing. Shallow water near shore.

Type locality. — Robert Bay, Martinique.

Known range. — Charleston, S.C., through West
Indies to Fernando Noronha Island (225 miles
northeast Cape Sao Roque), Brazil.

Remarks.— Pearse (1932a) determined freezing
point of blood in this species at Tortugas (range
-1.99° to -2.24° C).

Mithrax (Mithrax) hispidus (Herbst). Coral crab

Figures 236, 245C

Cancer hispidus Herbst, 1790, p. 245 (247 by error), pi. 18,
fig. 100.

Mithrax hispidus: Rathbun, 1925, p. 406, text-fig. 124, pis.
145-146 ; pi. 147, fig. 3 (rev.).

Recognition characters. — Carapace swollen,
considerably wider than long, smooth except for
some low, rounded prominences chiefly toward
outer margin of branchial region, gastric tubercles

Figure 236.— Mithrax (Mithrax) huipirfus (Herbst).
Male in dorsal vi<>\v. legs <>f left side not shown, 20 mm.
indicated.

256

FISH AND WILDLIFE SERVICE

faint; front wide. Rostral horns short, obtuse,
separated by a U-shaped notch. Preorbital angle
blunt, slightly produced. Basal article of antenna
with two teeth, inner one nearly as advanced as
rostrum, outer smaller one on orbital border. Or-
bit with four tubercles on margin, two superior
much smaller than external or inferior ones. An-
terolateral margin with four spiniform teeth, first
one obtuse, often bifid at tip ; second longer, sharp,
double, and curving forward; third and fourth
slender. Posterolateral border with a smaller
tooth situated higher on carapace in line with two
obliquely located tubercles, or a low spine and a
tubercle. Subhepatic region with two tubercles; a
few other tubercles on subbranchial and ptery-
gostomian regions.

Chelipeds large, unequal in males, equal in fe-
males; merus with four or five spines and a few
tubercles on upper surface and two spines on inner
margin; carpus smooth; hand smooth; fingers
spooned at tips, gaping, with a broad low crenu-
lated tooth near base of dactyl.

Measurements. — Carapace: large male, length,
102 mm. ; width, 146 mm.

Variations. — Young individuals have tubercles
on the carapace more protuberant than in the old.
Color. — Nearly uniform deep brownish-red or
terra cotta color above, brighter on chelipeds and
darker on legs (due to brown hairs) ; legs often
with brighter red bands at joints; underparts of
body mostly white or bluish white; legs red,
speckled with pale yellow (Verrill, 1908).

Habitat. — Commonly lives on rough bottom;
shallow water to 30 fathoms.
Type locality. — Unknown.

Known range. — Recorded in literature from as
far north as Delaware Bay (Say, 1818), off
Charleston Harbor, S.C., and Georgia (Gibbes,
1850). Bahamas and Florida Keys through West
Indies to Sao Paulo, Brazil ; Bermuda.

Mithrax (Mithrax) pleuracanthus Stimpson

Figures 237, 245D

Mithrax pleuracanthus Stimpson, 1871a, p. 116. — Milne Ed-
wards, 1875. p. 95. pi. 20. figs. 3-3f.— Rathbun, 1901, p. 68.—
Hay and Shore, 1918, p. 458, pi. 38, fig. 3.— Rathbun, 1925, p. 411,
pi. 150 (rev.).

Mithrax depressus Milne Edwards, 1875 (in part), p. 96, pi. 20.
figs. 4-4c— Rathbun, 1901, p. 68. — Verrill, 1908, p. 407, pi. 23,
fig. 1. — Hay and Shore, 1918, p. 458, pi. 38, fig. 2.

Mithrax hispidus Rathbun, 1892 (in part), p. 265.

Recognition characters. — Carapace not much
wider than long, conspicuously tuberculate ; front

Figure 237.— Mithrax (Mithrax) pleuracanthus Stimp-
son. Animal in dorsal view, legs of left side not shown,
10 mm. indicated.

wide. Rostral horns shorter and wider than in
M. hispidus, notch between horns narrower and
nearly triangular, always triangular in young in-
dividuals. Preorbital angle blunt, slightly pro-
duced ; orbit with two superior tubercles ; a small
postorbital angle and a suborbital tubercle. Basal
article of antenna with two teeth, inner one nearly
as advanced as rostrum, outer smaller one on
orbital border. Spines of anterolateral border
well developed, anterior one or two inclined to be
double, posterior two more acute and pointed for-
ward, small tubercles about base of spines. Gas-
tric region with transverse row of five tubercles,
in front of these, two pairs of tubercles, anterior
pair at base of rostral horns. Mesogastric region
with two tubercles on each side in a transverse
line. Cardiac region with three poorly defined
tubercles. Branchial area with four rather strong
tubercles and several smaller ones arranged more
or less in three oblique rows radiating from car-
diac region to anterolateral border.

Chelipeds large; merus with scattered low
spines on upper margin, with a simple spine, spine
and tubercle, or rounded eminence on inner mar-
gin, and five small spines on posterior border;
carpus smooth or with a few low tubercles on
upper surface; hands smooth; fingers slightly
gaping, dentate for nearly entire length, spoon-
shaped at tips. Walking legs dentate and hairy.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

257

Measurements. — Carapace: large male, length,
36 mm., width, 43 mm. ; ovigerous female, length,
16 mm., width, 19 mm.

Variations. — In young individuals the rostral
horns are wider behind and flatter than in adults ;
the notch between the rostral horns in extremely
large individuals may be U-shaped; the large
tubercle above the posterolateral margin may be
spiniform but is located higher on the carapace
than the similarly formed tubercle in M. hispidus.

Color. — Carapace yellowish white, with blotches
of bright red ; two largest red spots over branchial
areas, a median spot on cardiac area, a pair situ-
ated farther back, a small pair behind orbits, and
another beneath orbits; legs yellowish white,
blotched or barred with red ; chelae light red with
pale tips (Verrill, 1908, for M. depressus) .

Habitat. — This species, which is often encrusted
with bryozoans and other organisms, is found
predominantly on coarse or rocky substrates but
occasionally on muddy or sandy bottom. In North
Carolina it is a common species on the offshore
banks and is associated with Mithrax forceps.
Pearse (1934) found the species in canals of the
sponge Stematumenia strobilinia (Lamarck) at
Tortugas, Fla. Shallow water to 28 fathoms.

Type localities. — Key "West, 2-5 fathoms, Tor-
tugas, 5-6 fathoms [Fla.] ; St. Thomas.

Known range. — Beaufort, N.C., to Pensacola,
Fla.: Yucatan Channel off Cape Catoche, Mexico,
and Gulf of Campeche; West Indies to Venezuela;
Bermuda.

Remarks. — Ovigerous females are known in
Florida from December to February, and in
August. They are known from North Carolina
in April, St. Thomas in July, and Venezuela in
September (Rathbun, 1925; U.S. National Mu-
seum records).

Mithrax (Mithraculus) forceps (Milne Edwards)

Figures 238, 245E

Mithraculus forceps Milne Edwards, 1875, p. 109, pi. 23, fig. 1.
Mithrax forceps: Hay and shore, 1918, p. 457, pi. :>s, tig. l. —
Rathbun, 1925. p. 431, pi. 156 (rev.).

Recognition characters. — Carapace about one-
fifth wider than long, deeply sculptured in young
individuals but smoother with age. Anterolateral
margin with four tubercles or teeth exclusive of
postorbital angle, separated by broad rounded
sinuses, first tooth usually shortest, remainder
usually acute and turned forward at tip. Three

Figure 238. — Mithrax (Mithraculus) forceps (Milne
Edwards). Male in dorsal view, legs of left side not
shown, 5 mm. indicated.

grooves running diagonally backward over bran-
chial area from near first, second, and fourth
sinuses of anterolateral margin, between these
grooves two well-defined, unbroken ridges and a
broken ridge behind third groove. Cardiac and
gastric regions crossed by less sharply defined
ridges somewdiat broken up into low rounded
tubercles. Notch between rounded rostral horns
broadly V-shaped, two pairs of tubercles on
frontal region behind lobes of rostrum. Preorbital
angle prominent, not exceeding rostrum. Orbital
margin with a dorsal and ventral tubercle near
postorbital angle. Outer spine of fused antennal
article nearly equaling rostrum.

Chelipeds strong. Merus with two strong spines
or tubercles in front, five much smaller ones on
posterior margin, and usually two on upper sur-
face near posterior margin. Carpus smooth or
with a small spine or tubercle on inner margin
near inner distal angle. Hand smooth, polished,
somewhat tumid. Fingers widely gaping in male,
with expanded hollowed-out tips: dactyl with
single large tooth one-third distance from proxi-
mal end, or with a few minute teeth: immovable
linger with from one to three small teeth or tuber-
cles in middle. Walking legs spiny or denticulate
with many fine hairs.

258

FISH AND WILDLIFE SERVICE

Measurements. — Carapace: male, length, 21
mm. ; width, 25 mm.

Color. — Bed, approaching vermilion, with oc-
casional trace of purple. Terra cotta, or uniform
yellowish brown, varying to greenish brown;
often with a wide, pale yellow, median dorsal
stripe, and legs often banded, especially in young
individuals (various authors).

Habitat. — The species lives on rocky shores and
reefs in crevices, under stones and dead coral ; also
exposed between tides and in shallow water in cer-
tain areas (Verrill, 1908). In North Carolina this
form is found on offshore reefs and has been found
in the sponge Stematumenia strobilinia (La-
marck) at Dry Tortugas, Fla. (Pearse, 1934). In-
tertidal to 30 fathoms.

Type locality. — Guiana.

Known range. — From Cape Hatteras, N.C.,
through Gulf of Mexico to Rio de Janeiro, Brazil ;
Bermuda.

Remarks. — Ovigerous females have been taken
in Florida from November to February and from
June to August ; they are known from the Gulf of
Mexico in February, Curasao in April, Barbados
and Aruba in midsummer, and from Venezuela in
September and November (Bathbun, 1925; U.S.
National Museum records). Some of the larval
stages have been described by Lebour (1944).

Genus Microphrys H. Milne Edwards, 1851

Garth, 1958, p. 385.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace without lateral laminiform processes; one

strong branchial spine bicornutus (p. 259).

aa. Carapace with two lateral laminiform processes ; two
strong branchial spines antillcnsis (p. 260).

Microphrys bicornutus (Latreille)

Figures 239, 245P

Pisa bicornuta Latreille, 1825, p. 141.

Microphys bicornutus: Hay and Shore, 1918, p. 459, pi. 38,
fig. 10.— Rathbun, 1925, p. 489, text -fig. 139, pi. 175 (rev.).

Recognition characters. — Carapace subtriangu-
lar, moderately hairy, all raised parts covered
with rounded tubercles; a line of four tubercles
arching upward on intestinal region, branchial
region with two or three short spines and another
spine at lateral angle. Bostrum composed of two
stout horns, divergent throughout or divergent at
base with extremities curving inward, one-half to
one-third length of remainder of carapace. Basal

Figure 239. — Microphrys bicornutus (Latreille). Male
in dorsal view, legs of left side not shown, 10 mm.
indicated.

article of antenna with a conspicuous, flat, obtuse
spine at anterior angle and behind this a marginal
tubercle or a short stout spine in old individuals.
Orbits small, circular, with closed fissures, eyes
small, preorbital angle rectangular.

Chelipeds spotted, spots persisting for many
years in alcohol ; merus with three or four tuber-
cles or short, blunt spines above; carpus somewhat
nodose; hand smooth; fingers gaping, hollowed
out at tips. Walking legs diminishing noticeably
in length from first to fourth pair, hairy, margins
somewhat rough.

Abdomen of both sexes with seven separate
segments.

Measurements. — Carapace: male, length, 36
mm., width, 26 mm.; female, length, 24 mm.,
width, 20 mm.

Color. — Variable; carapace often dull yellowish
brown or bright purplish rose; chelipeds grayish
white, covered with small, round, purplish spots.

Habitat. — The species is common on coral reefs.
It is often disguised by foreign objects such as
sponges, anemone?, hydroids, algae, etc., which

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

259

became attached to it. Shallow water to 16.5
fathoms.

Type locality. — Nouvelle Hollande.

Known range. — Near Beaufort, N.C., to Cedar
Keys, Fla. ; Bahamas to Florianopolis, Santa
Catarina, Brazil ; Bermuda.

Remarks.- — Ovigerous females have been re-
ported from March to August in the Caribbean
area, and from November to January in the West
Indies, Venezuela, and Brazil (Rathbun, 1925;
U.S. National Museum records).

Pearse (1932b), working at Dry Tortugas,
listed the copepod Anthiacus intermedins from
the gill lamellae (accidental guest) and a tape-
worm plerocercoid, Rhyrtchobothrus, from the
viscera, and (in Wilson, 1935) reported a few
specimens of Cancrincola jamaicensis Wilson
from the branchial cavity of this crab.

Microphrys antillensis Rathbun

Figures 240, 245G

Microphrys antillensis Rathbun, 1920, p. 20. — 1925, p. 498,
text-fig. 141, pi. 176. figs. 3-4 (rev.).

Microphrys platysoma: Hay and Shore, 1918, p. 459, pi. 38,
fig. 9.

Recognition characters. — Carapace depressed,
tuberculate, and granulate, area at inner angle of
branchial region finely granulate; intestinal re-
gion with four large, equal tubercles. Anterolat-
eral wall with two laminiform processes, one on
hepatic, one on branchial region; hepatic process
with anterior end acute, projecting outward and
occasionally forward in large individuals, some-
times with outward-projecting tubercle at middle
of upper edge; a spine between and below level of
hepatic and branchial processes; branchial process
not rimmed nor sharply defined. Branchial re-
gion with three spines, one forming posterolateral
angle occasionally doubled. Posterior margin with
row of tubercles increasing in size medially. Ros-
tral horns slender, directed forward, about one-
sixth length of remainder of carapace. Basal arti-
cle of antenna with spine at outer angle about
half length of rostral spines. Orbits small, circu-
lar, with closed fissures; eyes small; preocular
spines acute, about half as long as antennal spines.

Merus of chelipeds with dentate and laminate
dorsal crest; carpus tuberculate; palm less than
twice as long as broad; fingers widely gaping, im-
movable finger strongly curved downward. Walk-
ing legs sparsely hairy and with a few spines and

Figure 240. — Microphrys antillensis Rathbun. Male in
dorsal view, legs of left side not shown, 5 mm.
indicated.

tubercles; propodi with prominent distal lamini-
form process for articulation of dactyls.

Abdomen of both sexes with seven free seg-
ments.

Measurements. — Carapace: male, length, 18
mm.; width, 16 mm. Length of rostral horns,
3 mm.

Habitat. — Two to 15 fathoms.

Type locality. — Off Montego Bay Point, Ja-
maica.

Known range. — Beaufort Harbor, N.C., to Cape
Fear, N.C. ; Cuba ; Jamaica ; Puerto Rico.

Remarks. — Ovigerous females have been re-
ported in September from North Carolina (Rath-
bun, 1925), in June from Florida, and November
from Bimini (U.S. National Museum records).

Genus Stenocionops Desmarest, 1823

Garth, 1958, p. 401.

KEY TO SPECIES IN THE CAROLINAS

a. Hepatic region not enlarged nor produced beyond gen-
eral outline of carapace, armed with not more than one
large spine.

260

FISH AND WILDLIFE SERVICE

b. Marginal spines behind orbit four, carapace with
about four median spiniform tubercles

■furcata coelata (p. 261).
bb. Marginal spines behind orbit three, carapace with
about eight median spines

spin interna ( young ) ( p. 262) .
aa. Hepatic region enlarged and produced separately
from curve of branchial region, marginal hepatic spines
3 : carapace with 12 or 13 median spines

spiniwana (adult) (p. 262).

Stenocionops furcata coelata (Milne Edwards)

Figures 241, 245H

Pericera coelata Milne Edwards. 1878, p. 224.
Stenocionops furcata. coelata: Hay and Shore, 1918, p. 460,
pi. 39, fig. 3.— Rathbun, 1925, p. 540, pi. 164 (rev.).

Recognition characters. — Carapace oblong-
ovate, approximately three- fourths as wide as
long, uneven, with strong spines and a dense cov-
ering of short setae and many scattered, longer,
hooked hairs. Rostrum consisting of two nearly
straight diverging horns with rows of hooked
setae. Orbital region broad, eyes small, retractile
within tubular orbits; preorbital spine strong,
suborbital and postorbital spines much smaller.

Figure 241. — Stenocionops furcata coelata (Milne Ed-
wards). Male in dorsal view, legs of right side in
part after Rathbun (1925), legs of left side not shown,
20 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLENAS
1763-049 O— -65 18

Basal antenna] article enlarged, armed with one
or two small distal spines or tubercles not visible
dorsally. Middorsal line with four strong spini-
form tubercles, one on gastric region, remainder
on cardiac and intestinal regions, fourth spine
with tip curved forward. Lateral border with
four stout spines, one on hepatic, remainder on
branchial region; in addition, two other stout
spines on branchial region and various smaller
ones toward front. Ventral surface of body, ex-
cept distal articles of chelipeds, closely covered
with bulbous setae hiding carapace.

Chelipeds in adult males fairly large and no-
dose; hand long, cylindrical, and granulate; fin-
gers approximately half as long as palm, gaping
in basal half, a tooth on dactyl near base. In other
individuals chelae weak; fingers less than half as
long as palm; merus with strong spines above near
distal end preceded by several smaller spines.
Walking legs moderately elongate, more or less
rough with clusters of hooked hairs, articles sub-
cylindrical.

Abdomen in male and female with seven dis-
tinct segments.

Measurements. — Carapace: large male, length,
137 mm.; width, 111 mm. Length rostral horn,
26 mm. Carapace : smaller male, length, 91 mm. ;
width, 64 mm. Length rostral horn, 25 mm.

Variations. — Large specimens have relatively
shorter rostral horns than smaller individuals;
young specimens are smoother than old ones.

Color. — Dark red.

Habitat. — This species is found on a variety of
bottoms, including fine white sand, yellow sand,
coarse gray sand, sand with algae, sandy shell,
broken shell, and coral. It has been reported most
often from coarse bottom (Rathbun, 1925), and
occurs on shelly reefs off Beaufort Inlet, N.C.
Shallow water near shore to 60 fathoms, rarely to
278 fathoms.

Type localities. — Ten miles from Jolbos Is-
lands [Yucatan], and near Havana [Cuba], 175
fathoms.

Known range. — Off Beaufort, N.C, to north-
west Florida and Alabama; Yucatan Channel;
West Indies to Barbados.

Remarks. — This species is similar to the typi-
cal subspecies 8. f. furcata which ranges from
Georgia to Bahia, Brazil, in shallow water near
shore to 35 fathoms depth. The typical subspecies
has the carapace more evenly sculptured and is

261

less spinous than S. f. coelata (Rathbun, 1925,
p. 449).

Ovigerous females are known in Florida from
March to August (U.S. National Museum rec-
ords).

Stenocionops spinimana (Rathbun)

Figures 242, 2451

Lioinia spinimana Rathbun, 1*92, p. 240, pi. 30.
Stenocionops spinosissima: Hay and Shore, 1918, p. 460, pi.
39, fig. 2.

Stenocionops spinimana: Rathbun, 1925, p. 457, pi. 267 (rev.).

Recognition characters. — Carapace subpyri-
form, convex, covered with sparse growth of
short, fine, curled hairs; 8 to 13 median dorsal
spines, and numerous other spines on gastric and
branchial regions; anterior marginal hepatic
spines 3, anterior-most spine small and occasion-
ally absent in old individuals. Rostral horns
widely divergent, straight, tapering gradually to
slender tip. Orbits tubular, not strongly project-
ing, eyes small, retractile within orbits; preorbital
spine acute, curving forward slightly at tip; post-
orbital spine similar in size to spine near antero-
lateral angle of basal article of antenna.

Merus and carpus of chelipeds with numerous
spines, hand rough throughout length with two
rows of spines above, one below, spines becoming
progressively smaller distally. "Walking legs with
a few spines. Meral articles with a terminal spine
above, and on first leg a longitudinal inner-upper
row of five or six, and a ring of about four spines
near distal end; on second leg a ring of three or
four; on third and fourth only one or two spines
besides terminal one. Carpus of first leg with
three or four spines, second with three spinules or
tubercles, third and fourth with one.

Abdomen in male and female with seven seg-
ments, six free in females.

Measurements in millimeters

Large
male

Holotype

spinimana

(male)

Half-
grown
male

Young
female

Length of carapace, including horns...
Width of carapace, including spines...
Width of carapace, excluding spines...

130

118

110

89
76
69
10

53
42
36
10

18
13
10
3

Variatwns. — This species exhibits great change
in shape and spination with increasing age, as has

Figure 242. — Stenocionops spinimana (Rathbun). Holotypic male in dorsal view (after Rathbun, 1892).
262 FISH AND WILDLIFE SERVICE

been pointed out by Rathbun (1925), and Garth
(1958) for related forms. Young individuals are
much different in shape from adults, having a
width considerably less than length (width about
70 percent of length including spines and ros-
trum), whereas the mature animals are more
rounded in contour (large adult male, with about
90 percent of length). Old individuals have a
thicker coating of hair than immature ones, espe-
cially on the chelipeds. Chelipeds in old indi-
viduals become quite large and stout with the
palm compressed (length more than twice that
of carapace). The young have fewer spines than
adults, the hepatic region is not expanded and
bears only one marginal spine as opposed to three
spines in adults.

Habitat. — The species has been found on a va-
riety of bottoms, from gray mud, through various
grades of sand, to sand-shell, coral, and rock
(Rathbun, 1925). Twenty to 124 fathoms.

Type locality. — Off Cape Lookout, N.C., 124
fathoms.

Known range. — Off Cape Hatteras, N.C., to
Florida Straits and Gulf of Mexico off Mobile
Bay, Ala.

Remarks. — Ovigerous females have been re-
ported from South Carolina in December (Rath-
bun, 1925).

Genus Macrocoeloma Miers, 1879

Garth, 1958, p. 4,12.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace without dorsal spines in addition to epi-
branchial and posterior spines trispinosum (p. 263).

aa. Carapace with dorsal spines in addition to epibran-
chial and posterior spines camptocerum (p. 264).

Macrocoeloma trispinosum (Latreille) . Grass crab, sponge
crab, decorator crab

Figures 243, 245J

Pisa trispinosa Latreille, 1825, p. 142>

Macrocoeloma trispinosum: Hay and Shore, 1918, p. 457, pi. 38,
fig. 11— Rathbun, 1925, p. 466, text-fig. 132, pi. 166, fig. 1; pi.
167 (rev.).

Recognition characters. — Carapace irregularly
triangular, body and legs with velvety covering
of short brown hairs, thick and swollen, wide at
level of orbits, narrowing distinctly in hepatic
portion, widening again posteriorly. Middorsal
region much elevated and bearing four low,
rounded tubercles or bosses, one on gastric, one on
cardiac, and one on each epibranchial region.

Figure 243. — Maei-ocoeloma trispinosum (Latreille). A,
small male in dorsal view, legs of left side not shown,
10 mm. indicated ; B, right chela of adult male in
frontal view.

Posterolateral angle prolonged into a long flat-
tened spine directed obliquely outward and back-
ward, sometimes curved upward; posterior mar-
gin with broad, median, triangular projection
with tip sometimes slightly recurved. Rostrum
formed of two somewhat flattened horns adjacent
and subparallel at base, divergent distally. Eyes
retractile within roomy, projecting, tubular orbits,
upper margin of orbit deeply emarginate, pre- and
post-ocular teeth prominent, preocular teeth
curved forward. Basal article of antenna with
inner angle produced, exceeding frontal margin,
and forming a broad spine directed obliquely out-
ward at each side of rostrum.

Chelipeds of male narrow, approximately as
long as carapace; merus nodose; palm with sub-
parallel sides; dactyl approximately half as long
as upper margin of palm and lightly furrowed
above. Walking legs rather slender, slightly
nodose.

Abdomen with seven separate segments in both
sexes.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

263

Measurements. — Carapace: male, length, 34
mm. ; width, 29 mm.

Variations. — Eathbun (1925) discussed varia-
tion in this species throughout its known range.
Body shapes falling into three general series are
distinguishable. In the first, the typical form, the
posterolateral prominences are narrow, with reg-
ularly tapering spines, projecting beyond the gen-
eral outline of the carapace and directed more or
less backward, and sometimes strongly curved
from base to tip with the concavity forward. Tiie
carapace is considerably constricted behind the
orbits. The orbits are prominent owing to this
constriction, and the pre- and post-ocular teeth
are strong, the former directed forward and
curved. The upper edge of the orbit is deeply
emarginate. The four large tubercles or bosses are
prominent, some or all with an acute tip, that on
the gastric region sometimes nearly a spine.

In the second series, treated by Rathbun as an
unnamed variety, the posterolateral prominences
are wider than in the first series, less spinelike
and more laminate, their hind margins nearly
transverse. The carapace is less narrowed behind
the orbits, the orbital teeth less marked, though
the preocular tooth is directed forward and a
little curved, and the superior emargination less
deep. The four large dorsal bosses are lower than
in series one, but the gastric boss tends to be
surmounted by a sharp tubercle or granule.

In series three, called M. t. nodipes, the postero-
lateral prominences are broader and more obtuse
than in series two with their margins almost con-
tinuing the margin of the carapace. The carapace
is constricted little or not at all behind the orbits ;
the preocular tooth is acute but not prominent,
and the postocular tooth blunt or subacute with
both teeth somewhat more prominent in young
individuals than in old ones. The orbit has a
slight emargination in the upper border. The
dorsal bosses are lower than in the other series,
smoothly rounded and blunt.

In the three series the posterior median spine
varies in a manner similar to the lateral spines.
Within the three series, the rostrum shows great
variability in length, direction, and curvature of
the horns.

< 'olor. — Hairs yellowish or reddish brown
(various authors).

Habitat. — In North Carolina, this species has
been found in seaweed in Beaufort Harbor, in the
ocean on floating masses of Sarga-ssum, and
dredged from offshore reefs. Elsewhere it has
been found in a variety of situations, from pilings
and mangrove roots to weedy rocks, coarse-coral
sand, sand-shell, and broken-shell bottoms. The
species is often concealed by a covering of sponge.
Shallow water to 45 fathoms.

Type locality. — Nouvelle Holland (?) [error].

Known range. — Beaufort, N.C., to Alligator
Harbor, Fla. ; Yucatan; through West Indies to
off Cape Sao Roque, Brazil.

Remarks. — Ovigerous females have been re-
ported from southern Florida in December, Cuba
in April, and Jamaica and St. Thomas in July
(Rathbun, 1925; U.S. National Museum records).

Macrocoeloma camptocerum (Stimpson)
Figures 244, 245K

Pericera camptocera Stimpson, 1871a, p. 112.
Macrocoeloma campterocerum: Hay and Shore, 1918, p. 457, pi.
Rathbun, 1925, p. 469, pi. 174, fig. 4 ; pi. 270, fig. 2

38, fig. 12
(rev.)

Recognition characters. — Carapace irregularly
triangular; surface covered with short, close

Figure 244. — Macrocncloma ramptnrcrum (Stimpson).
Male in dorsal view, legs of left side not shown, 10 mm.
indicated.

264

FISH AND WILDLIFE SERVICE

Figure 245. — Subfamily Mithracinae, tips of right first pleopods of males; A, Mithrax spinosissimus (Lamarck),
sternal view; B, Mithrax verrucosus H. Milne Edwards, sternal view; C, Mithrax hispid us (Herbst), sternal
view; D, Mithrax pleuracanthus Stimpson, sternal view; E, Mithrax forceps (Milne Edwards), sternal view;
F, Microphriis oicornutus (Latreille). sternal view: G, Microphrys antillcnsis Rathbun, sternal view; H, Steno-
cionops furcata coelata (Milne Edwards), sternal view; I, Stenocionops spinimana (Rathbun), sternal view;
J, Macrocoeloma trispinosum (Latreille), lateral view; K, Macrocoeloma camptocerum (Stimpson), lateral view;
0.33 mm. indicated.

pubescence, and, in addition, long, stiff, curled
hairs on front, gastric region, and lateral portions
of branchial regions; wide at level of orbits, nar-
rowing distinctly in hepatic portion, widening
again posteriorly; with four strong spines on
dorsal region, one on gastric, one on cardiac, and
one on each epibranchial region. Posterolateral
spines subcorneal, regularly tapering, acute, and
directed slightly backward; posterior median
spine shorter, acute, obliquely erect. Rostral horns
acute, rather regularly divergent from base.
Spines on basal article of antennae rather slender,
divergent. Orbital tubes, pre- and post-orbital
spines protuberant laterally, preorbital spine
curving a little forward.

Chelipeds of male strong, longer than carapace;
merus with a few short spinules above; carpus

somewhat nodose with a tubercle at inner angle;
palm widest near articulation; fingers tipped
with black or dark brown. Walking legs nearly
smooth.

Abdomen with seven separate segments. in both
sexes.

Measurements. — Carapace: male, length, 40
mm., width, 36 mm.; female, length, 24 mm.,
width, 20 mm.

Variations. — The rostral horns may be straight
or slightly curved outward at tips, and range in
length from one-sixth to one-third the total length
of the carapace. The interspace between horns
may vary from a narrow V-shape to almost a
right angle. The posterolateral spine may be
straight in frontal section or curved upward and
nearly transverse or directed strongly backward.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

265

Color. — A dirty brown.

Habitat. — The species has been taken on a
variety of bottoms ranging from sand with grass,
or a hard smooth substrate, to rocky or coral
bottoms. Rathbun (1925) reported the form from
predominantly coarse bottoms. About 2 to 13
fathoms.

Type locality. — Near Key West [Fla.], in from
2 to 5 fathoms.

Known range. — Beaufort Harbor, N.C., via
southern Florida to Alligator Harbor, Fla.

Remarks. — Ovigerous females are known in
Florida from January to March (U.S. National
Museum records).

Family Parthenopidae

Eyes usually retractile within small, circular,
well-defined orbits, floor of orbit nearly continued
to front, leaving a hiatus usually filled by second
[article] of antennary peduncle. Basal antennal
[article] small, deeply imbedded, between inner
angle of orbit and antennulary fossae. Antennules
folding somewhat obliquely (Alcock, 1895).

Subfamily Parthenopinae

Carapace commonly equilaterally triangular,
sometimes subpentagonal or ovate-pentagonal,
and sometimes almost semicircular or semiellipti-
cal in outline. Cardiac and gastric regions usually
deeply marked off from branchial regions on
either side, making dorsal surface of carapace
trilobed. Rostrum simple or obscurely trilobed.
Chelipeds vastly longer and more massive than
walking legs (Alcock, 1895). First pleopod vary-
ing, more or less stout, apically tapering or not
tapering; second pleopod usually short and of
usual shape (Stephensen, 1945).

KEY TO GENERA IN THE CAROLINAS

(Modified after Rathbun, 1925)

a. Carapace not laterally expanded over walking legs,
b. Carapace tuberculate or eroded _/'«r?/icji ope (p. 266).
bb. Carapace smooth, except for a few strong spines

Solenolambrus i p. 270).
aa. Carapace more or less expanded forming a vault be-
neath which walking legs are concealed

Heterocrypta (p. 270).

Genus Parthenope Weber, 1795

Garth, 1958, p. 434.

KEY TO SPECIES IN THE CAROLINAS

a. Carapace ovate-pentagonal, surface scarcely carinate

in adult (Subgenus Parthenope) agona (p. 266).

aa. Carapace broadly triangular, carinate or tuberculate,
with more or less rounded sides

(Subgenus Platyl-ambrus).
b. Carapace and chelipeds very flat; spine at end of

main dorsal branchial ridge small scrrata (p. 267).

bli. Carapace convex, chelipeds not flat ; spine at end
of main dorsal branchial ridge large,
e. Carapace much broader than long ; hand with 8-12
teeth on inner, 10-12 on outer margin

pourtalesii (p. 268).
cc. Carapace not much, if any, broader than long ;
hand with few good sized marginal teeth, six to
eight on inner, three to five on outer margin

fraterculus (p. 269).

Parthenope (Parthenope) agona (Stimpson)

Figures 246, 252iA

Lambrus agonus Stimpson, 1871a. p. 131.

Parthenope agona: Hay and Shore, 1918, p. 4i82, pi. 39, fig. 5.
Parthenope agonus: Rathbun, 1925, p. 513, text-fig. 146, pis.
178-179 ; pi. 275, figs. 1-3 (rev.).

Recognition characters. — Carapace ovate-pen-
tagonal or subcircular, somewhat broader than
long, with rounded sides, without angles. Post-
orbital constriction slight, not involving ptery-
gostomian ridge continuing from lower side of
orbit to point above cheliped. Depressions be-

Figitre 246. — Parthenope {Parthenope) agona (Stimp-
son). Male in dorsal view, position of legs recon-
structed, walking legs of left side not shown, 10 mm.
indicated.

266

FISH AND WILDLIFE SERVICE

tween regions of carapace not markedly deep;
surface coarsely punctate or eroded, and with
numerous granules and tubercles, larger tubercles
more or less spiniform and arranged as follows:
five on gastric region, three on cardiac, one on
each side of urocardiac lobe, five on branchial,
and one on each hepatic region. Anterolateral
margin of branchial region with six small teeth,
below and behind last tooth a broad triangular
tooth, and still lower on ventral surface a spine
visible between ischia of cheliped and first leg.
Median rostral tooth narrow, produced, dentic-
ulate at base, an acute forward-pointing tooth
over each antennular cavity. Orbit with several
spines on outer margin, a suture above, open
below; eye with small spine on upper surface. A
conical spine or tubercle on each side of sternum
near base of chelipeds.

Chelipeds long, slender (length of merus ap-
proximately 1.3 times width of carapace), pris-
matic, upper surface finely rugose. Merus and
carpus with an irregular row of dentiform tuber-
cles near middle of upper surface, on inner and
outer margins, and near outer margin of hand.
Upper margin of hand with row of 18-20 ir-
regular teeth, largest near base of fingers but
decreasing in size both proximally and distally;
outer margin with 4 to 6 larger teeth and many
intermediate smaller ones. Walking legs long,
slender, bare, and almost smooth.

Second segment of abdomen with sharp trans-
verse crest.

Measurements. — Carapace: male, length, 20
mm. ; width, 21 mm. Length of merus, 30 mm.

Variations. — The rostrum may be broadly tri-
angular, subentire, instead of tridentate with
denticulate margins. In young individuals the
pterygostomian ridge is less developed anteriorly,
and the post orbital constriction is more evident.

Color. — Light buff, somewhat marbled with
purple, chelipeds and legs with broad bands of
purple.

Habitat. — The species has been reported from
predominantly sandy or broken-shell bottom
(Rathbun, 1925) ; 25 to 115 fathoms.

Type localities. — Off the Marquesas, Carysfort
Reef, and Conch Reef, 40 and 49 fathoms [south-
ern Florida].

Known range. — Off Capes Hatteras and Look-
out, N.C.; Gulf of Mexico near Pensacola, Fla.,

through Florida Straits; Puerto Rico; Trinidad;
between British and Dutch Guiana.

Remarks. — Ovigerous females have been taken
from southwestern Florida in March (Rathbun,
1925), and off the Guianas in September (U.S.
National Museum records).

Parthenope (Platylambrus) serrata (H. Milne Edwards)
Figures 247, 252B

Lambrus serratus H. Milne Edwards, 1834, p. 357.

Platylambrus serratus: Hay and Shore, 1918, p. 463, pi. 39,
fig. 7.

Parthenope serrata: Rathbun, 1925, p. 516, pis. 180-181 ; pi.
275, figs. 7-10 (rev.).

Recognition characters. — Carapace depressed,
width approximately 1.5 times length; convex
anterolateral margin of branchial region with
seven to nine triangular teeth in front of long,
flat, lateral spine. Posterolateral margin concave;
posterior margin convex, wide, both margins to-
gether with seven tubercles noticeably larger than
others, each terminating an indefinite longitudinal
or oblique line of tubercles. Elevations of cara-
pace ornamented with numerous unequal granu-
lated tubercles; depression between gastric and
branchial regions deep. Rostrum short, tridentate,
narrow at tip, and with raised margin continuous
with superior wall of orbits. Pterygostomian and
subhepatic regions with an excavation reaching
margin of orbit and, with chelipeds retracted,
forming covered efferent passages.

Chelipeds, when extended, approximately 2 to
2.5 times as long as carapace, trigonal, smooth
beneath, more or less tuberculate on upper sur-

Figubb 247. — Parthenope (Platylambrus) serrrata (H.
Milne Edwards). Male in dorsal view, 10 mm.
indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

267

face, and with margins cut into lanceolate or tri-
angular teeth fringed with fine hairs, much
stronger on outer than on inner side of articles;
hand with about nine teeth alternately large and
small; fingers stout, oblique. Walking legs of
moderate size, longest not exceeding merus of
cheliped.

Abdomen of male with segments three to five
fused, sixth segment with a median spine.

Measurements. — Carapace: male, length, 19
mm.; width, 28 mm. Length of cheliped, 60 mm.

Color. — Eed somewhat mottled with gray;
fingers carmine, shading to black.

Habitat. — The species has been reported from a
variety of bottoms ranging from coral to fine sand
and mud, but it has been taken most often from
muddy or sandy bottoms (Rathbun, 1925;
Holthuis, 1959). Shallow water to 60 fathoms.

Type locality. — V Ocean indien [erroneous
locality].

Known range. — Off the three North Carolina
capes, Gulf of Mexico from Pensacola to southern
Florida, and off Campeche, Mexico; West Indies
to Bahia, Brazil.

Remarks. — Hildebrand (1955) and Holthuis
(1959) added distributional extensions to Cam-
peche and Surinam. Ovigerous females have been
reported in May and June from Surinam
(Holthuis, 1959). They are known from North
Carolina in June, Florida in summer, and Cuba
in October (U.S. National Museum records).

Parthenope (Platylambrus) pourtalesii (Stimpson)

Figures 248, 252C

Lambrus pourtalesii Stimpson, 1871a, p. 129.
Parthenope pourtalesii: Hay and Shore, 1918, p. 462, pi. 39,
fig. 6.— Rathbun, 1925, p. 521, pis. 182, 183, and 276 (rev.).

Recognition characters. — Carapace broadly
ovate-triangular, convex; branchial regions rather
deeply separated from gastric, cardiac, and
hepatic regions. Posterolateral angle marked by
conspicuous laciniated spine located behind bulg-
ing curve of anterolateral margin; hepatic mar-
gin armed with a small but prominent spine.
Anterolateral margin behind cervical suture
armed with eight or nine teeth and spines, first
three or four shorter than remainder. Postero-
lateral margin with three or four unequal spines
in addition to large one on ridge; posterior mar-
gin with three large and several small spines.
Genera] surface of carapace pitted and eroded,

Figure 248. — Parthenope (Platylambrus) pourtalesii
(Stimpson). Female in dorsal view, approximately
X 0.80 (after Smith, 1887).

with granulated tubercles disposed as follows:
one gastric, one genital, two cardiac, two on
branchial ridge in line with lateral spine, and a
tendency to rows of tubercles on branchial re-
gions. Rostrum with a long, narrow, obtuse tooth
with a denticle on each side, a subacute basal
tooth, and below and outside this a short spine.
Supraorbital spine blunt, postorbital spine smaller
but somewhat sharper; upper side of emargina-
tion on eye spined.

Chelipeds long, rough, armed with laciniated
teeth and spines on both margins; merus witli an
additional median row of spiniform tubercles on
upper surface: carpus with largest spine at inner
angle ; hand with an obsolete median row beneath.
Meri of walking legs spinulose, also carpus and
propodus of last pair; dactyls furred; a tubercle
on sternum at base of cheliped and each of legs
one to three.

Abdomen with a large tubercle .in middle of
second to sixth abdominal segments and a conical
tubercle at extremity of segments two and three;
segments three to five fused in male. Lower sur-
face of body granulate and tuberculate.

Measurements. — Carapace: male, length, 36
mm.; width, 47 mm. Length of cheliped, 122 mm.
Carapace: ovigerous female, length, 11 mm.;
width, 13 mm.

Variations. — The species varies greatly in the
number and prominence of tubercles and teeth,
and in constriction and ornamentation of the
rostrum. The elevations of the carapace may bear
spines or tubercles.

268

FISH AND WILDLIFE SERVICE

Color. — Purplish red with cross bands of buff
on chelipeds and walking legs; palms pinkish
brown (various authors).

Habitat. — The species is found predominantly
on sand or sandy mud bottoms (Rathbun, 1925) ;
10 to 134 fathoms.

Type localities. — Off Conch Reef, French Reef,
and American Shoal [southern Florida].

Known range. — Off Marthas Vineyard, Mass.;
latitude of New Jersey through West Indies to
Grenada.

Remarks
North Carolina in December

Ovigerous females are known from

Parthenope (Platylambrus) fraterculus (Stimpson)

Figures 249, 252D

Lamorus fraterculus Stimpson, 1871a, p. 130.
Parthenope fraterculus: Rathbun, 1925, p. 525, pis. 186-187 ;
pi. 190, fig. 2 (rev.).

Recognition characters. — Carapace subtriangu-
lar, approximately four sided, posterolateral mar-
gins continuous with sides of posterior margin,
and long anterolateral margins in line with
rostral borders. Depressions separating branchial
from cardiac and hepatic regions deep; cardiac

Figure 249. — Parthenope (Platylambrus) fraterculus
(Stimpson). Male in dorsal view, position of legs
reconstructed, legs of left side not shown, 5 mm.
indicated.

and gastric regions connected by a narrow ridge,
hepatic and branchial regions by a wider ridge
bounded below by a deep hollow visible in side
view; hepatic region with a large submarginal
tubercle visible in dorsal view. Margin of
branchial region cut, into 11 to 13 small teeth;
posterior margin with 3 equal teeth. Prominences
of carapace ornamented with a few large tubercles
and spines as follows: three gastric in a triangle,
one genital, two cardiac, and three on branchial
ridge. Front inclined about 45 degrees, ending in
a narrow, blunt tooth, a blunt tooth on each side
above antennules, and outside, below these, a
small slender spine. A tubercle on preorbital lobe ;
orbit with a small blunt tooth on inner lower
angle and a large tubercle between this and angle
of buccal cavity. Endognath with row of five
tubercles near outer margin.

Chelipeds of male approximately 2.5 times as
long as carapace ; inner, outer, and upper margins
of merus with a few unequal stout spines; inner
and outer margin of hand armed with triangular,
denticulate, unequal teeth, six or seven larger ones
on inner, three or four on outer margin; largest
tubercle on upper surface at proximal third coni-
cal. Walking legs with meri denticulate; dactyls
furred except at tip; carpus and propodus of
last pair with two or three lobes above and five
denticles below.

Sternum and abdomen tuberculate, second to
sixth abdominal segment with a large transverse
tubercle.

Measurements. — Carapace: male, length, 16
mm., width, 17 mm.; female, length, 16 mm.,
width, 18 mm.

Variations. — There is great individual varia-
tion in the nature of tubercles and spines. In
some individuals the prominences are low and
blunt, in others high and sharp. The front may
vary in degree of inclination, and margins of the
frontal lobes and orbits may be denticulate, entire
or subentire.

Color. — Uniform red, eggs bright red (various
authors).

Habitat. — The species has been taken predomi-
nantly on rocky or shelly bottoms (Rathbun,
1925; Holthuis, 1959) ; 4 to 110 fathoms.

Type localities. — Off Sand Key, Carysfort and
Conch Reefs, West of Tortugas, 26 to 68 fathoms
[southern Florida].

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

269

Known range. — Off Cape Fear, N.C. ; Gulf of
Mexico, off Cape San Bias, Fla., to Florida
Straits; off Cape Catoche, Yucatan, Mexico;
through West Indies to mouth of Amazon River
(U.S. National Museum records).

Remarks. — Ovigerous females have been re-
ported in May from southern Florida (Rathbun,
1925), and August from northeastern Florida
(U.S. National Museum records).

Genus Solenolambrus Stimpson, 1871

Garth, 1958, p. 458.

Solenolambrus tenellus Stimpson

Figure 250

Solenolambrus tenellus Stimpson, 1871a, p. 134. — Hay and
Shore, 1918, p. 463, pi. 39, fig. 8. — Rathbun, 1925, p. 541, pi.
194, figs. 3-4 ; pi. 279, figs. 5-9 (rev.).

Recognition characters. — Small delicate species.
Carapace but little broader than long and about
equally produced in front of and behind line of
lateral angles; surface punctate; protuberances
of gastric and cardiac regions fairly well marked
near posterolateral margin but almost obsolete
anteriorly. Anterolateral margins of carapace
crenulated, five or six teeth on expanded and
broadly rounded lateral angle being most promi-
nent and defined chiefly by impressed lines on
marginal shelf; hepatic region with two or three
denticulate teeth. Posterolateral margin concave;
posterior margin convex, its lateral angles obtuse.

Solenolam'brus tenellus Stimpson, Female
lew, walking legs of loft side not shown,
3 mm. indicated.

Rostrum rather prominent, faintly tridentate at
extremity, median tooth smallest and most promi-
nent. External angle of orbit not prominent;
eyes large with extremely minute tubercle at
summit. Basal article of antenna approximately
as long as next article. External maxilliped with
ischium somewhat tuberculate near outer margin
and extremity.

Chelipeds long, slender, general surface smooth,
polished; edges denticulate. Merits with about
13 teeth on either edge, third tooth from distal
end larger than others. Hand with 12 sharp for-
ward-curving teeth on superior edge, terminal
tooth above finger spiniform and considerably
longer than others; outer margin with about 11
small teeth, inner with 19 or 20 minute teeth.
Walking legs naked, compressed, without lamini-
form crests; merus of last pair slightly expanded
below near base.

Abdomen and sternum of male coarsely pitted,
otherwise smooth and glabrous.

Measurements. — Carapace : male, length, 6 mm. ;
width, 6 mm. Length of cheliped, 16 mm. Cara-
pace: ovigerous female, length, 5 mm.; width, 6
mm.

Habitat.— Thirty to 115 fathoms.

Type localities. — Off Carysfort, Conch, and
French Reefs, 35 to 49 fathoms [southern Flor-
ida].

Known range. — Off Cape Lookout, N.C. ; Gulf
of Mexico, near Cape St. George, Fla., to Florida
Keys; Bahamas; Barbados.

Remarks. — Ovigerous females have been re-
ported in May from Barbados, May and June
from Florida (Rathbun, 1925), and questionably
in August from North Carolina (an incompletely
labeled specimen from Hay and Shore's material
in Institute of Fisheries Research collection, and
Fish Hawk records for 1902).

Genus Heterocrypta Stimpson, 1871

Garth, 1958, p. 473.
Heterocrypta granulata (Gibbes). Pentagon crab
Figures 251, 252E

Cryptopodia granulata Gibbes, 1850, p. 173.

Heterocrypta granulata: Hay and Shore. 1918, p. 464. pi. 39,
fig. 9.— Rathbun, 1925, p. 555, text-fig. 152, pi. 203, figs. 1-2;
pi. 282, figs. 1-3 (rev.).

Recognition characters. — Carapace subtriangii-
lar, with wide clypeiform vaulted expansions,
length two-thirds width; general surface smooth,

270

FISH AND WILDLIFE SERVICE

Figure 251. — Heterocrypta granulata (Gibbes). Male in
dorsal view, 10 mm. indicated.

punctate; margins crenulate. Anterolateral mar-
gin nearly straight, with dorsal surface sloping
upward from margin to prominent, granulate
branchial ridge running parallel with each side,
these connected by a short transverse ridge on

gastric region and joined behind to posterior
marginal ridge. Rostrum broad, blunt, deflexed,
with rounded margins connected to gastric ridge
by a pair of granulate crests. Orbits small,
nearly circular; eyes small, retractile. Cardiac
region with a large domelike elevation granulated
at summit.

Chelipeds unequal, rather heavy, longer than
width of carapace; outer and inner margins of
upper surface of merus, carpus, and hand ex-
panded into irregular granulate or dentate crests;
fingers short, agape in larger cheliped. Walking
legs short, almost completely hidden beneath
carapace.

Sternum and lower surface of abdomen coarsely
granulate; male abdomen with third, fourth, and
fifth segments fused, sixth segment with a sharp
proximal appressed spine with tip lying between
two tubercles on fifth segment.

Measurements. — Carapace: male, length, 12
mm., width, 18 mm.; female, length, 15 mm.,
width, 21 mm.

Figure 252.— Family Parthenopidae, first and second right pleopods of males; A, Parthenope agona (Stimpson),
medial view; B, Parthenope serrata (H. Milne Edwards), medial view; C, Parthenope pourtalesii (Stimpson),
medial view; D, Parthenope fraterculus (Stimpson), medial view; E, Heterocrypta granulata (Gibbes), medio-
sternal view ; 1 mm. indicated.

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

271

Color. — Varying from light gray to nearly
black, usually commingled so as to produce an
irregular mottling or marbling (various authors).

Habitat. — This species is found on shingly
bottoms, and not infrequently on shelly bottoms
in Morehead City, N.C., harbor. Its angular form
and coloration bear so close a resemblance to
fragments of shells among which it lives that it
is extremely difficult to detect. Two to 75 fathoms.

Type localities. — Near Kiawah Island, Sul-
livans Island, and White Point Shoal, Charleston
Harbor, S.C.

Known range. — Nantucket Sound, Mass., to
Georgia; Florida Straits to Sabine, Tex.; through
West Indies to St. Thomas.

Remarks. — Ovigerous females are found in the
Beaufort, N.C., area throughout the summer.

ACKNOWLEDGMENTS

Considerable aid was provided for completing
this revision. The Society of the Sigma Xi gave
a grant-in-aid to help with curatorial duties in
the Institute of Fisheries Research Collection.
National Science Foundation gave two grants
(G-5638 and G-18545) for study, travel, cura-
torial expenses, and illustration. Without these
grants, the work would not have been possible.

Fenner A. Chace, Jr., Senior Scientist, Depart-
ment of Zoology, U.S. National Museum, gave
encouragement and counsel, and aided greatly by
providing space for study at the USNM, and by
loaning specimens. G. Robert Lunz, Director,
Bears Bluff Laboratories, Wadmalaw Island, S.C,
extended similar help; and E. Milby Burton,
Curator, The Charleston Museum, provided study
space and made loans of specimens. L. B.
Holthuis, Rijksniuseum van Natuurlijke Historie,
Leiden, gave counsel and many kindnesses. My

associates, A. F. Chestnut, E. E. Deubler, W. E.
Fahy, W. A. Lund, H. J. Porter, G. S. Posner,
and W. J. Woods, helped with many details; and
my colleagues in nearby laboratories of the U.S.
Fish and Wildlife Service, Bureau of Commercial
Fisheries and Duke University, Beaufort, N.C.,
provided botli field data and other help.

Special thanks are due my assistant, George W.
Bryce, Jr., .who did much of the curatorial and
photographic work, and the able artist, Doris H.
King, who drew all original figures except the
map.

Figures copied from source material are
credited to authors in the text. Publishers, in-
stitutions, and journals who kindly gave permis-
sion to reproduce these figures are: American
Museum of Natural History; Bingham Oceano-
graphic Laboratory; Biological Bulletin; British
Museum (Natural History) ; Caraibisch Marien-
Biologisch Instituut, Curasao; Charleston Mu-
seum ; Connecticut Academy of Arts and Sciences;
Institut Oeeanographique, Monaco; Koninklijke
Nederlandse Akademie van Wetenschappen,
Amsterdam; John Murray, London; Journal of
the Elisha Mitchell Scientific Society; Marine
Laboratory, University of Miami; Martinus
Nijhoff, The Hague; Museum of Comparative
Zoology, Harvard University; National Museum
(formerly Raffles Museum), Singapore; New
York Academy of Sciences ; New York Zoological
Society; Pennsylvania Academy of Sciences;
Rijksmuseum van Natuurlijke Historie; Smith-
sonian Institution, LT.S. National Museum; Texas
Academy of Science; U.S. Fish and Wildlife
Service, Bureau of Commercial Fisheries; Uni-
versitetets Zoologiske Museum, Copenhagen; Uni-
versity of Southern California, Allan Hancock
Foundation; Washington Academy of Sciences.

272

FISH AND WILDLIFE SERVICE

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1937. Color changes in Brachyura Crustaceans,
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1957. Larval development of Neopanope lexana sayi
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1962. Ecological studies of the larval development
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1959. List of references on the biology of shrimp.
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1958. Life-history and biology of the oyster crab,
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1919. Life history of the blue crab. Bulletin of the
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FISH AND WILDLIFE SERVICE

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1941. On the growth and ecology of brachyuran
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1944. Color changes of fiddler crabs (Genus Uca) in
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1950. Repetition of egg laying and number of eggs
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1952. Sexual dimorphism in weight and length rela-
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1950. Evidence of a homing instinct in the Bermuda
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1960. Marsh crab, intertidal tunnel-maker and grass-
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1957. A partial bibliography of the genus Callinectes.
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1918. Note on the coloration of Planes minutus.
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1961. Maturation and spawning of the pink shrimp
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1959. Crustacea Brachyura. Duas novas ocor-
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1852. Conspectus Crustaceorum, etc. Conspectus
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277

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1934. The mechanism of asymmetry in the Al-
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1935. Intersexuality in the Crustacea. Papers from
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Darnell, Rezneat M.

1959. Studies of the life history oi the blue crab
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1961. Trophic spectrum of an estuarine community,
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1952. The blue crab investigation, 1949-50. Texas
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1949. Florida crawfish research. Gulf and Carib-
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1954. A bibliography of the lobster and the spiny
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1963. Notes on Stenopus scutellatus Rankin and
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1951. Investigations on the Florida spiny lobster,
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1926. Notes on the behavior of the fiddler crab.
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1957. Respiratory metabolism of fhe fiddler crab
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1867. In I. Desbonne and A. Schramm, Crustac6s de
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1961. Early developmental stages of pink shrimp,
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DUNCKER, G.

1934. Gefangenschaftbeobachtungen an Sesarma
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1940. A Pleistocene occurrence of Libinia dubia,
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1950. The influence of eyestalk removal on the
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1943. The influence of temperature and season upon
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1959. A report on the shrimp (Penaeidae) collected
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1962. The attachment of the barnacle, Balanus
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1961. Biological observations on the commercial
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1905. Notes on the commensals found in the tubes
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1775. Systema entomologiae, sistens insectorum
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1781. Species insectorum exhibentes eorum differ-
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1879. On some young stages in the development of
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1956. A prenaupliosoma stage in the larval develop-
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1958. Invertebrates from the estuarine portion of
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1955. Persistent daily and tidal rhythms of color
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1956. Phase difference in the tidal rhythums of
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1957. Relation between position of burrows and tidal
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Fingerman, Milton, and Donald W. Tinkle.

1956. Responses of the white chromatophores of
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1941. Deconditioning the "fright reflex" in the
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1959. Occurrence of extremely small ovigerous crabs
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1925. Seasonal distribution of the plankton of the
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Flemister, Launce J.

1958. Salt and water anatomy, constancy and
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Flemister, Launce J., and Sarah C. Flemister.

1951. Chloride ion regulation and oxygen consump-
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1946. Littoral brachyuran fauna of the Galapagos
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1958. Brachyura of the Pacific Coast of America,
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1850. On the carcinological collections of the United
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1898. The crustacean genus Scyllarides. Science
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1937. Pinnixa lunzi a new commensal crab from
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1953. Crabs from the island of St. Thomas. Pro-
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1956. A bibliography of pagurid crabs, exclusive of
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Gordon, I.

1938. A comparison of the two genera Albunea and
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a new species from Singapore. Bulletin of the
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1950. Crustacea Dromiacea. Part I. Systematic
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Gould, Augustus A.

1841. Report on the invertebrata of Massachusetts,
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Gray, E. H.

1942. Ecological and life history aspects of the red-
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1957. A comparative study of the gill area of crabs.
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1961. Changes in abundance of the commensal crabs

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1853. III. Melanges et Nouvelles. Revue et Maga-

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1960. La stridulation chez les crabes. Crustaceana,
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Gunter, Gordon.

1937. Observations on the river shrimp, Machrobra-
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1950. Seasonal population changes and distributions
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1956. Principles of shrimp fishery management.
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1957. Misuse of generic names of shrimp (Family
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1961. Habitat of juvenile shrimp (Family Penaei-
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1962a. Specific names of the Atlantic American
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1962b. Reply to Dr. L. B. Holthuis on the names of
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1954. The relation of total rainfall of the State and
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Gurney, Robert.

1936a. Notes on some decapod crustaceans of Ber-
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Proceedings of the Zoological Society of London for
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1936b. Notes on some decapod Crustacea of Ber-
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1939. A late larval stage of the sargassum prawn,
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cyst of the adult. Annals and Magazine of Natural
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1943a. Notes on Periclimenes americanus and the
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1943b. The larval development of two penaeid
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Gurnet, Robert, and Marie V. Lebour.

1941. On the larvae of certain Crustacea Macrura,
mainly from Bermuda. Journal of the Linnaean
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GuTSELL, J. S.

1928. The spider crab, Libinia dubia, and the jelly-
fish, Stomolophus meleagris found associated at
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GUYSELMAN, J. B.

1953. An analysis of the molting process in the
fiddler crab, Uca pugilalor. Biological Bulletin,
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Haig, Janet.

1956. The Gahtheidae (Crustacea Anomura) of the
Allan Hancock Expedition with a review of the
Porcellanidae of the western Atlantic. Allan
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1960. The Porcellanidae (Crustacea Anomura) of
the eastern Pacific. Allan Hancock Pacific Ex-
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Hall, D. N. F.

1956. The Malayan Penaeidae (Crustacea, Deca-
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1885. On some genera and species of Penaeidae,
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1887. XXI. — Report on the decapod Crustacea of
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1952. The sand crab Emerita talpoida (Say) and
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1904. An establishment of association in hermit crabs
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MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

289

1954. Exploratory shrimp fishing in the Gulf of
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1945. Pinnotheres ostreum parasitic on the American
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1914. South African Crustacea (Part VII of South
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1945. The Brachyura of the Iranian Gulf. With
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1952. Some observations of the breeding and migra-
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1953. Further observations on the breeding and
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1958. Distribution of fiddler crabs in Georgia salt
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290

FISH AND WILDLIFE SERVICE

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1954. The molting cycle of the spiny lobster,
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Trtjitt, R. V.

1939. Our water resources and their conservation.
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1960. New York City's wholesale fishery trade,
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1958. The blue crab and its fishery in Chesapeake
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1956. Study of the oxygen consumption of excised
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Verwet, J.

1957. A plea for the study of temperature influence
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1947. Observacoes s6bre a maturaca6 de Xypho-
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1920. Report of the biologist. Fourth Biennial

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1955. A key to the commercial and potentially
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State of Florida Board of Conservation, Technical
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1956. Protective coloration and habitat of the
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Wass, Marvin L.

1955. The decapod crustaceans of Alligator Harbor

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The Quarterly Journal of the Florida Academy of

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1954. A persistent diurnal rhythm of chromato-

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2 text-figs.

MARINE DECAPOD CRUSTACEANS OF THE CAROLLNAS

291

Wells, Harry W., Mart Jane Wells, and I. E. Gray.
1960. Marine sponges of North Carolina. Journal

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1932. Temperature and light as factors influencing
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Weymouth, F. W., Milton J. Lindner, and W. W.
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1933. Preliminary report on the life history of the
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Wharton, George W.

1942. A typical sand beach animal, the mole crab,
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1937. Further observations on lunar periodicity.
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1847a. Short descriptions of some new species of
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1948. The distribution of larger planktonic Crustacea
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Wiegmann, A. F. A.

1836. Beschreibung, einiger neuen Crustaceen des
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1953. Identification of juvenile shrimp (Penaeidae)
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1955a. A contribution to the life histories of com-
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Bulletin of Marine Science of the Gulf and Carib-
bean, vol. 5, No. 2, pp. 116-146, 8 text-figs.

1955b. A survey of the North Carolina shrimp
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text-figs.

1955c. The genus Ogyrides in North Carolina.
Journal of the Washington Academy of Sciences,
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1958. Substrates as a factor in shrimp distribution.
Limnology and Oceanography, vol. 3, No. 3, pp.
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1959. Spotted and brown shrimp postlarvae (Penaeus)
in North Carolina. Bulletin of Marine Science of
the Gulf and Caribbean, vol. 9, No. 3, pp. 281-290,
4 text-figs.

1960. The influence of temperature on osmotic
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1962. A re-examination of Ovalipes species in the
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1947. A comparative size study of the mole crab
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Willis, E. R.

1942. Some mud-shrimps of the Louisiana coast.
Occasional Papers of the Marine Laboratory, Baton
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Wilson, Charles Branch.

1935. Parasitic copepods from the Dry Tortugas.
Papers from Tortugas Laboratory, Carnegie Insti-
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1933. Clarence A. Shore and his earlier years in
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1954. Occurrence of two East American species of
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1959. Morphology of the white shrimp Penaeus
setiferus (Linnaeus, 1758). U.S. Fish and Wildlife
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1-168, 89 text-figs.

292

FISH AND WILDLIFE SERVICE

SYSTEMATIC INDEX

Page

Acanthocarpus - 156

alexandri 156

gibbesi 224

Acanthony chinae 248

Acetes 39

americanus 39

americanus earolinae 39

carolinae 39

Achelous ordwayi 166

spinicarpus 167

Aciaea erosa 185

Albunea 136

gibbesii 136

oxyophthalma 137

paretii 137

paretoi 137

synmista 136

Albuneidae 136

Alpheidae 62

Alpheus. 63

affinis 65

armillatus 67

formosus 64

heterochaelis 66

minus 70

normanni 65

packardii 65

saulcyi 73

Amphitrite depressifrons 166

Anasimus 240

latus 240

Anchista americana 43

Anagasia carolinensis 83

Anomalopus furcillatus 236

Anomalothir 236

furcillatus 236

Anomura 104

Arctus americanus 96

Arenaeus 173

cribrarius 173

Automate 62

kingsley i 62

Batrachonotus 238

f ragosus 238

Brachy carpus 51

biunguiculatus 51

Brachygnatha 160

Brachy rhyncha 160

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS
763-049 0—65 20

Brachyura.--
Calappa

angusta.

flammea.

ocellata-

sulcata. -
Calappidae. -

Page
142

- 152

- 154

152

153

155

152

Calap pi nae 152

Callianassa 100

atlantica 102

(Callichirus) atlantica 102

(Callichirus) major 100

maj or 100

stimpsoni. _. 102

Callianassidae 99

Callichirus major 100

Callinectes 168

ornatus 172

sapidus 168

Cancer . 174

aculeatus 177

barbatus - . 146

borealis 175

depressus 223

diogenes 122

epheliticus. _ 158

flammeus 152

gonagra 182

hispidus- 256

irroratus 175

limosa 199

mercenaria 183

minutus 218

ocellatus 160

pudibundus. - 157

quadratus. - 225

sabulosa_ - - 145

seticornis 244

setiferus - _ 18

Cancridae 174

Caridea 41

Carpoporus 186

papulosus 186

Clibanarius 120

vittatus 120

Collodes 239

trispinosus 239

Concordia gibberosus 79

293

Fag*

CoraUiocaris wilsoni - 46

Crago septemspinosa 89

Crangon 88

armillatus 67

formosus - 64

heterochaelis 66

packardii- 65

septemspinosa 89

Crangonidae 88

Cronius 174

ruber.. 174

Cryptopodia granulata 270

Cymopolia alternata 215

faxoni. - 216

Dardanus 123

insignia 124

venosus 123

Decapoda 11

Diogeninae 115

Dissodactylus 209

mellitae — 209

Dromiacea - - 143

Dromidia 143

antillensis 143

Dromiidae. - 143

Ebalia - 147

can osa 147

Ebaliinae 147

Echinophilis mellitae 209

Emerita - - - 139

benedicti 139

talpoida-- - - --- 140

Epialtus 249

dilatatus 249

Eriphia 182

gonagra 182

Euceramus - 109

praelongus 109

Euchirograpsus — 220

americanus 220

Eupagurus annulipes _ 130

brevidactylus 132

corallin us 134

defensus 127

discoidalis 134

impressus 129

pygmaeus 131

Euprognatha 237

rastellifera 237

rastellifera marthae.- 237

Eurypanopeus 194

abbreviatus 194

depres8us 195

Euryplax 202

nitida... 202

Eury tium 199

li mosum 199

Eusicyonia brevirostris 35

dorsalis 37

edwardsii 38

Page

laevigata 33

parri 34

Galatha- 33

Galathea 105

rostrata 105

Gala theidae 104

Galatheidea _. 104

Gebia affinis 103

Gelasimus minax 227

pugnax 229

Glyptoxanthus 1 85

erosus 185

Gnathophyllidae 61

Gnathophyllum 61

modestum 61

Goneplacidae 201

Goneplax 201

hirsuta. 201

Grapsidae 217

Grapsinae. 217

Grapsus cinereus _. 222

trans versus ._ 217

Gymnopleura - 142

Haliporus tropicalis 15

Harpilius 43

Hepatus 157

epheliticus 158

princeps 157

pudibundus. 157

Heterocrypta 270

granulata 270

Hexapanopeus — 188

angustifrons 188

paulensis 189

Hippa emerita 140

talpoida. . - -- 140

Hippidae. -- 139

Hippidea 136

Hippolysmata 84

(Exhippolysmata) oplophoroides 85

(Hippolysmata) wurdemanni 84

wurdemanni 84

Hippolyte -• 80

pleuracan tha 80

wurdemanni 84

zostericola -- 82

Hippolytidae 76

Homola 146

barbata 146

Homolidae 146

Hymenopenaeus 15

tropicalis 15

Hypoconcha 144

arcuata 144

sabulosa - 145

Iliacantha 150

in termedia 151

subglobosa 150

Inachinae 236

294

FISH AND WILDLIFE SERVICE

Page

Lambrus agonus 266

fraterculus 269

pourtalesii 268

serratus 267

Latreutes 78

ensiferus 78

fucorum 78

parvulus 79

Leander 55

tenuicornis 55

Lepidopa 138

websteri 138

Lepidops venusta 138

Leptochela 41

serratorbita 41

Leptodius 192

agassizii 192

Leptopodia calcarata 243

Leucosiidae 147

Libinia 251

dubia 252

emarginata 252

spinimana 262

Lithadia cariosa 147

pontifera 149

Lobopilimnus 181

agassizii 181

Lucifer 40

faxoni 40

Luciferinae 40

Lupa gibbesii 164

haatata 168

sayi 163

Lupea anceps 163

Macrobrachium 52

acanthurus 52

ohione 54

Macrocoeloma 263

camptocerum 264

trispinosum 263

Macropipinae 160

Macrura 90

Maia spinosissima 254

Majidae 236

Matutinae 157

Megalobrachium 112

soriatum 112

Menippe 183

mercenaria 183

Metoporhapis 243

calcarata 243

calcaratus 243

Micropanope 192

nuttingi 194

sculptipes 193

xanthiformis 193

Microphrys 259

antillensis 260

bicornutus 259

platysoma 260

MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS

Page

Mithracinae 254

Mithraculus forceps 258

Mithrax 254

depressus 257

forceps 258

hispidus 256, 257

(Mithraculus) forceps 258

(Mithrax) hispidus 256

(Mithrax) pleuracanthus 257

(Mithrax) spinosissimus 254

(Mithrax) verrucosus 255

pleuracanthus 257

spinosissimus 254

verrucosus 255

Munida 105

irrasa 105

Natantia 14

Neopanope 190

texana nigrodigita 190

texana sayi __ 190

texana texana 190

Neopontonides 49

beaufortensis 49

Nibilia _ 251

antilocapra 251

Nika bermudensis 86

Ocypoda pugilator 232

Ocypode 225

albicans , 225

quadrata 225

reticulatus.. 22 1

Ocypodidae 225

Ogyrides. j .. 74

alphaerostris _. 75

limicola. 74

Ogyrididae .. . . 74

Ogyris alphaerostris 75

Ophthalmiinae. 246

Oreophorus nodosus _. 148

Osachila 159

semilevis 159

tuberosa 159

Othonia lherminieri. - 246

O valipes ._.. 160

guadulpensis 161

ocellatus 160

ocellatus floridanus 161

ocellatus guadulpensis. 161

ocellatus ocellatus.. 160

Oxyrhyncha 235

Oxystomata 146

Pachycheles 108

pilosus.. 108

rugimanus 108

Pachygrapsus 217

trans versus 217

Paguridae 114

Paguridea 114

Pagurinae 125

295

Pag«

Pagurlstes - 115

armatus -- 118

lymani 116

moorei 115

rectif rona 1 1 •

sericeus 117

spinipes 118

tortugae 119

triangulatua 118

visor 118

Pagurus. - 125

annulipes 130

brevidactylus -- 132

defensus . - - 127

impressus. - 129

insignis 124

longicarpus 125

pollicaris 128

pygmaeua 131

venosus 123

vittatus 120

Palaemon acanthurus 52

biunguiculatus 51

f ucorum 78

ohionis 54

tenuicornis 55

vulgaris - . 56

Palaemonetes _- — 56

carolinus 56

(Palaemonetes) intermedius 58

(Palaemonetes) pugio 59

(Palaemonetes) vulgaris 56

vulgaris 56, 59

Palaemonidae 42

Palaemoninae 50

Palicidae 215

Palicus... 215

alternatus 215

f axoni 216

Pallnuridae - - 91

Palinurus argus - 91

Pandalidae -- 87

Panopeus - 196

abbreviatus.- 194

angustifrons 188

depressus 195

herbstii 196

occidentalis 198

sayi 190

texanua — 190

Pantomua 88

parvulua 88

Panulirua -- - 91

argus 91

Parapenaeua. - 27

goodei 29

longirostri8 27

politus 27

Parapinnixa 208

bouvieri 208

Pag€

Parartemesia tropicalis 15

Parthenope 266

agona 266

agonus 266

fraterculus 269

(Parthenope) agona 266

(Platylambrus) fraterculus 269

(Platylambrus) pourtalesii 268

(Platylambrus) serrata 267

pourtalesii 268

serrata 267

Parthenopidae 266

Parthenopinae 266

Pasiphaeidae 41

Pelia 250

mutica 250

Penaeidae 14

Penaeidea 14

Penaeinae 17

Penaeopsis 29

goodei 29

Penaeus 17

aztecua 24

brasiliensis 21, 24

brasiliensis aztecus 24

constrictus 31

duorarum 21

fluviatilis 18

setiferus 18

Peneus kroyeri 30

longirostris 27

Percnon 224

gibbesi 224

Pericera camptocera 264

coelata 261

Periclimenaeus 45

schmitti 45

wilsoni 46

Periclimenes 42

beaufortensis 49

(Harpilius) americanus 43

longicaudatus 42

Persephona 150

punctata 150

punctata aquilonaris 150

Petrochirus 122

diogenes 122

bahamensis 122

Petrolisthes 107

galathinus 107

Philyrinae 150

Pisa antilocapra 251

bicornuta 259

mutica 250

trispinosa 263

Pisidia sayana 110

Pisinae 250

Pilumnus 177

agassizii 181

dasypodus 178

296

FISH AND WILDLIFE SERVICE

Page

floridanus 179

harrisii 187

lacteus 180

pannosus 181

sayi 177

Pinnixa 210

chaetopterana 210

cristata 210

cylindrica 213

lunzi 214

retinens 212

sayana 212

Pinnothereliinae 210

Pinnotheres 203

cylindricum 213

depressum 203

depressus 203

maculatum 206

maculatus 206

ostreum 203

Pinnotheridae 203

Pinnotherinae 203

Pitho 246

lherminieri.. 246

Plagusia.. 223

depressa 223

Plagusiinae 223

Planes 218

minutus 218

Platylambrus serratus 267

Podochela 241

gracilipes 243

riisei 241

sidneyi 242

Pontonia 47

domestica 47

margarita 48

Pontoniinae 42

Polyonyx 113

gibbesi 113

macrocheles 113

Porcellana 110

galathina 107

macrocheles 113

pilosa 108

sayana 110

sigsbeiana 111

soriata 112

Porcellanidae 106

Porcellanopsis soriata 112

Portunidae 160

Portuninae 162

Portunus 162

anceps 163

cribrarius 173

depressifrons. 166

gibbesii 164

guadulpensis 161

ord wayi 166

ruber 174

MARINE DECAPOD CRUSTACEANS OF THE CAROLENAS

Page

sayi 163

spinicarpus 167

spinimanus 165

Processa 86

bermudensis 86

canaliculata 86

Processidae 86

Pylopagurus __ 133

corallinus 134

discoidalis 134

rosaceus 135

Pyromaia 240

cuspidata 240

Ranilia 142

muricata 142

Raninidae 142

Reptantia 90

Rhithropanopeus 187

harrisii 187

Rynchocyclus parvulus 79

Scyllaridae 94

Scyllaridea 90

Scyllarides 98

americanus 98

nodif er 98

Scyllarus 94

americanus 95, 96

arctus paradoxus 97

chacei 95

nearctus 97

nodifer 98

Sergestidae 38

Sergestinae 39

Sesarma 221

cinerea 222

cinereum 222

(Holometopus) cinereum 222

reticulata 22 1

reticulatum 22 1

(Sesarma) reticulatum 221

Sesarminae 221

Sicyonia 33

brevirostris 35

carinata 36

dorsalis 37, 38

edwardsii 36

laevigata 33

parri 34

stimpsoni 38

typica 36

Sicyoninae__ 32

Solenocera 15

atlantidis 15

weymouthi 15

Solenocerinae 14

Solenolambrus 270

tenellus 270

Speloeophorus 148

nodosus 148

pontif er 149

297

Page

pontifera 149

Speocarcinus 202

carolinensis 202

Sphenocarcinus 248

corrosus 248

Spiropagurus 133

dispar 133

Stenocionops 260

furcata coelata 261

spinimana 262

spinosissima 262

Stenorynchus 244

Sagittarius 244

seticornis _ 244

Synalpheus 69

f ritzmuelleri 69

longicarpus 73

minus 70

to wnsendi 72

Synhimantites typica 36

Thalassinidea 99

Thelxiope barbata 146

Page

Thor 7g

floridanus 75

Tozeuma 83

carolinense 83

carolinensis 83

Trachypenaeus 31

constrictus 31

Tyche 247

emarginata 247

Uca 227

minax 227

pugilator 232

pugnax 229

Upogebia 103

affinis 103

Urocaris longicaudata 42

Varuninae 220

Virbius pleuracanthus 80

zostericola 82

Xanthias nuttingi 194

Xanthidae 176

Xiphopeneus 30

kroyeri 30

298

FISH AND WILDLIFE SERVICE

U.S. GOVERNMENT PRINTING OFFICE : 1965 O — 763-049

ANNUAL MARKS ON SHELL AND LIGAMENT OF SEA SCALLOP
(PLACOPECTEN MAGELLANICUS)

By Arthur S. Merrill, Julius A. Posgay, and Fred E. Nichy, Fishery Biologists (Research), Bureau of
Commercial Fisheries Biological Laboratory, Woods Hole, Mass.

ABSTRACT

The annual rings on the shell of the sea scallop are
frequently weak or obscured by other rings caused by
some nonannual stress. Methods are presented by
which it is possible to locate the true annual rings by
reference to marks on the resilium, changes in shell
curvature, changes in color pattern, weight of the shell,
and areas of attack by boring organisms. The results

obtained are validated by comparing a growth rate
derived through location of the annual rings with one
derived from the growth increments of a large sample
which had been tagged and released and recaptured
after a year at large. The objectivity of the criteria
used to identify the annual rings was tested.

ANNUAL MARKS

Many investigators have been able to determine
the growth rate of various species of mollusks by
identifying those rings on the shell that are caused
by some consistent annual phenomenon. Measur-
ing the amount of shell between the rings provides
data from which it is possible to estimate growth
rates for various areas and year classes. Cana-
dian investigators (Stevenson and Dickie, 1954;
Dickie, 1955) succeeded in applying this technique
to the sea scallop, Placopecten magellanicus
(Gmelin), of the Bay of Fundy. Dickie (per-
sonal communication) also succeeded, with some
difficulty, in locating annual rings on the sea
scallops of Georges Bank. His difficulty was
caused by the fact that the annual rings are
usually rather weak and frequently masked by
the presence of strong shock rings. Sea scallops
are rather sensitive creatures, and any serious
disturbance causes them to mark the event with
a shock ring on the shell (Posgay, 1950). The
grounds that interest us most are those on Georges
Bank, which sustain the heaviest fishing pressure
and where concentrated dredging operations

Note.— Approved for publication August 28, 1961.

may cause uncaught scallops to form many
shock rings (fig. 1).

Because of the difficulties of interpreting the
rings on the shell, we have examined some of the
other hard parts of the sea scallop for charac-
teristics that might offer clues to age. The
most useful of these structures proved to be the
calcareous part of the resilium. Areas attacked
by boring organisms, weight of the shell, color
changes, and changes in the curvature of the
shell also provided valuable clues to age.

This paper describes the methods used to
determine the position of the annual rings, gives
the result of applying them to a sample of shells,
compares the derived growth rate with the growth
rate determined from tagged and recaptured
animals, and gives the result of an experiment
testing the objectivity of the criteria. Each
phase of the work was carried out by a different
investigator to avoid subjective bias.

RINGS ON THE SHELL

The surface of the shell of the sea scallop is
covered with a series of fine concentric lines
(circuli) as a result of the addition of new shell
along the margin during growth. At intervals,

FISHERY BULLETIN: VOLUME 65, NO. 2

299

Figure 1. — Upper valve of sea scallop showing strong shock rings and weak annual rings.

the circuli are more closely spaced and give the
appearance of a band or ring (fig. 2). These
bands are laid down annually as the result of a
decrease in the rate of growth much as has been
demonstrated for tree rings and fish scales. Al-
though the cause has not yet been demonstrated,
we believe that it is low winter temperatures.
Specimens from shallow water (fig. 3), where
winters are more severe, have more prominent
rings than those from deeper water where tem-

peratures vary less. Georges Bank, with an
average annual temperature range of 8°-12° C,
has a particularly equable climate for sea scallops.
Posgay (1953) has shown that sea scallops grow
fastest at about 10° C. In his experiments,
the rate dropped to about 95 percent of the
maximum at 8° C. and to about 80 percent at
12° C.

In addition to the annual rings, most sea scallop
shells exhibit other annuli which mark nonannunl

300

U.S. FISH AND WILDLIFE SERVICE

Figure 2. — Closeup view of a portion of the upper valve
of a sea scallop, showing a band of narrowly spaced
circuli between two areas of widely spaced circuli.

phenomena. In shallow water, a severe storm
may cause sufficient disturbance on the bottom
to cause the scallops to form shock rings. Off-
shore, shock rings are usually caused by dredging
activities of the fishing fleet. Lightly fished areas
yield unmarked scallops, while heavily fished
areas yield scallops whose shells are a confusion
of shock rings. These injuries are sometimes so
severe as to distort the shape of the shell (fig. 4).
On Georges Bank, which provides more than 75
percent of the sea scallop catch, both phenomena,
weak annual rings and many shock rings, combine
to make the location of the annual rings difficult
(fig. 1). Not all scallops, however, react in the
same, degree to the stress that causes the annual
ring. Any reasonably large sample will contain
some sensitive individuals bearing clear annual
rings. Likewise, not all scallops are subjected to
disturbances sufficient to cause many shock rings.
It is usually possible, therefore, to sort out at least
a few shells which are fairly easy to interpret.
While such a small sample of selected individuals
cannot give a valid estimate of the growth rate of
the population, it can give an idea of what to
expect from the rest of the sample. The more
deeply curved valve, which is uppermost when the
scallop is at rest, usually bears the clearest annual
rings; but in some individuals, the lower valve will
be more easily interpreted.

MARKS ON THE LIGAMENT

The structure and the function of the ligament
in Pecten have been fully described by Trueman
(1953a, and 1953b). The outer layer (fig. 5) unites
the two valves and acts as a flexible hinge. The
inner layer, the resilium, is composed of a large,
dark-brown, conical, central structure of rubbery,
noncalcareous material and two small lateral
calcareous plates, which cement the resilium into
a shallow socket, the resilifer, on each valve. The
resilium acts as a sort of compressible spring work-
ing in opposition to the adductor muscle. When
the muscle is relaxed, the resilium forces the
margins of the valves apart.

As the scallop grows and adds new shell along
the margins, it also adds new material to the liga-
ment. When shell growth slows or ceases, liga-
ment growth also slows or ceases producing a
mark. The resilium, and the epithelial cells which
produce it are well protected and less exposed to
shock and injury than are the margins of the shell
and the cells which produce it. Therefore, marks
on the resilium caused by an annual period of slow
growth are relatively more prominent compared
with shock marks than are the corresponding
marks on the shell. The spaces between the bands
on the resilium are proportional to the spaces
between the bands on the shell; hence, a specific
area of the resilium can be referred to a corre-
sponding part of the shell. This section of the
shell can then be studied closely in search of the
annual ring.

Figure 6 shows the upper valve of a sea scallop,
selected because of its distinct annual rings and
lack of strong shock rings, which has been sawed
down the midline. The numbers indicate annual
rings. Figure 7 shows the resulting cross section
of the hinge area of the same scallop. The dark
area in the center of the cross section is the resil-
ium ; the lighter areas immediately to the left and
right are the calcareous plates. The numbered,
darker bands on the plates and the constrictions
of the resilium correspond to the five annual rings
on the shell.

It is not necessary to make a cross section in
order to observe the annual marks on the plates
of the resilium. When the valves of a sea scallop
are separated, the resilium usually splits down the
middle. After drying for a few days, the remain-
ing half of the resilium, including the attached

ANNUAL MARKS ON SHELL OF SEA SCALLOP

301

Figure 3. — Upper valve of a sea scallop taken from shallow water showing prominent annual rings.

calcareous plate, can be easily picked out of the
resilifer. The plate can then be examined with a
low-power microscope or hand lens (fig. 8). If
the ligament has been lost, it is still possible to
examine the corresponding impression on the
resilifer.

OTHER SHELL CHARACTERISTICS

In some areas, annual invasions of boring or-
ganisms infect the upper valve of the sea scallop
(figs. 6 and 9). The areas of heaviest infestation
can be easily seen if the shell is held over a strong

302

light. The annual rings can usually be located
between the infected areas. The weight of the
shell is sometimes an index of rate of growth. A
thin shell is usually the sign of a fast growing
individual; a thick, heavy shell usually means
slow growth. Some shells exhibit areas of convex
curvature between the annual rings (fig. 10). The
profile of these shells, held at arm's length, show a
series of hills and valleys. The annual rings can
usually be found in the valleys. An occasional
shell, or sample of shells from particular areas,
will show changes in color pattern of an annual

U.S. FISH AND WILDLIFE SERVICE

Figure 4. — Upper valve of a sea scallop taken from a heavily fished area, showing
malformation as a result of injury to the mantle.

nature which may help to locate the rings (fig. 11).
Figures 9, 10, and 11 represent selected indi-
viduals; obviously, not all shells are so strikingly
marked.

READING A SAMPLE

The shells to be read must first be cleaned of all
foreign matter. It is best to soak them in a strong
solution of a nonbleaching detergent and then
scrub them with a wire brush. The length fre-
quency is determined to see if the sample is
polymodal. We define length for these purposes
as being measured along the greatest diameter of
the shell from umbo to opposite margin. Shells
that do not have a large number of shock rings
and appear to have prominent annual rings are

then sorted out. The shells and resilia of these
individuals are studied first, and a preliminary
table of length at time of annual ring formation
is prepared.

With this table as a guide to the most probable
location of the annual rings the rest of the sample
is read. It is best to work from the smaller to the
larger specimens. All of the clues mentioned pre-
viously are used as occasion demands and oppor-
tunity affords. The more difficult shells are set
aside until the last when the averages and the
deviations are more firmly established. These, as
well as the larger, older shells with the annual
rings near the margin crowded together, can
usually be best interpreted by reference to the
resilia.

ANNUAL MARKS ON SHELL OF SEA SCALLOP

303

Figure 5.— Hinge and ligament of the sea scallop, (a) Outer layer of the ligament at hinge line, (b) resilifei,
(c) calcareous plates of the resilium, (d) compressible part of the resilium, and (e) surface view of calcareous
plate.

VALIDATION OF THE METHOD

In September of 1957, we had tagged and
released 5,375 sea scallops on the northeast peak
of Georges Bank. A fine hole is drilled in the ear
of the upper valve just over the byssal notch in
the lower valve. A stainless steel pin, bearing a
numbered Petersen disc and a 6-inch yellow plastic
streamer, is pushed through the hole and bent
over to hold the tag securely (fig. 12). The animal
is not wounded but the disturbance of dredging,
handling, and tagging is sufficient to put a strong
shock ring on the shell. The margin is nicked
with a triangular file so that this tagging shock
ring can be identified with certainty later. After
recapture it is simple to measure how much new
shell has been added since the date of tagging
and, with a large enough sample, calculate the
growth rule.

This particular tagging experiment had been
very successful and we had a great many shells
from recaptured animals. One group of 411 had
been recaptured only a few weeks after release
and therefore bad added very little new shell.

With the techniques described previously, the
annual rings on this group were located and the
shell lengths at the time of formation of each ring
measured (table 1). The Walford (1946) regres-
sion equation calculated from the average length
at the time of ring formation is: L,+i = 42.4 + 0.706
Lt (equation 1).

We also had 392 shells from animals that had
been captured, tagged, and released at the same

Table 1. — Average length (mm.) at time of ring formation
for 8 year classes in sample of 411 sea scallops and aver-
age for all year classes combined

Ring No.

Year class

Aver-
age

2-.

22.0
54.1
84.4

20.4
52.7
80.8
100.9

21.3
52.1
80.5
100.3
112.4

20.6
50.7
78.6
97.4
110.7
120.4

23.5
55.5
79.6
97.9
110.5
119.9
126.4

21.1
50.6
78.2
97. K
109.4
119.3
126.9
132.2

18.9
52 7
80.3
97.9
110.5
119.6
127.4
132.3
136.1

24.7
56.3
83.3
99.1
110.3
119.2
126.3
131.8
136.2
139.2

20.7

52.6
80.7
98.7

110.6

ll«.l. 7

126.7

132.1

'.1

136. 1

139.2

Number
Hi yeai
class

304

U.S. FISH AND WILDLIFE SERVICE

Figure 6. — Sea scallop shell with five prominent annual
rings. The shell between the rings shows annual
attacks by boring organisms.

Figure 7. — Cross section of hinge of sea scallop showing
annual marks in the calcareous plates of the resilium.

Figure 8. — Calcareous plate of a resilium showing banding
and constriction in response to some annual stress.

time and location but which had been at large
from 48 to 68 weeks before being recaptured.
These shells were grouped by 2-week intervals,
and the length when tagged (Ls) and the length
when recaptured (Z,r) measured on each one (table
2). The Walford (1946) regression of length at
recapture on length when tagged was then cal-
culated for each of the five groups. The tabula-
tion below shows the number in each sample, the
time at large, and the slope and intercept of the
regression equations.

ANNUAL MARKS ON SHELL OF SEA SCALLOP

305

Sample No.

Weeks out

Slope

Intercept

140
89
46
62
55

49.6
58.1
60.7
64.1
66.7

0.6384
.6430
.6601
.5897
.5879

50.30

50.53

48.16

57.20

57.42

These regression equations, each of which repre-
sented growth for a different time interval, were
then transformed to a common, 52-week, time
interval using Lindner's (1953) method.

Sample No.

Weeks out

Slope

Intercept

52
52
52
52
52

0. 6248
.6735
.7005
.6516
.6608

52.21

47.26

Taking an average slope and intercept gives
Z(+1 = 47.3 + 0.662 L, (equation 2) as the estimate
of growth per year by this method.

Figure 9.— Upper valve showing the result of heavy invasion of boring organisms. The annual rings
are located between the areas of heaviest damage.

306

U.S. FISH AND WILDLIFE SERVICE

Figure 10. — Profile of the upper valve of a sea scallop. The annual rings are found in the

areas of concave curvature.

Table 2. — Length (mm.) of 392 sea scallops when tagged
(L„) and released at latitude lil°52' N., longitude 66°23'
W., on Sept. 22, 1957, and when recaptured (Lr) about 1
year later

SAMPLE 1. OUT 49.6 WEEKS

85.0

109.6

102.2

115.0

111.9

120.5

119.2

126.9

125.4

128.7

89.1

110.2

102.5

120.6

112.0

124.9

119.2

127.7

125. 4

130.7

89.9

107.1

102.6

116.1

112.2

120.9

119.2

132.3

125.7

135. 0

90.1

104.7

102. 8

120. 6

112.3

125.9

119.3

122.3

126.2

129.4

90.8

110.1

103.3

113.8

112.8

123.1

119.4

126.2

126.3

133.1

90.9

111.0

104.2

117.3

114.0

120.0

119.5

122.3

126.5

129.4

91.0

106.5

104.7

115.7

114.1

123.2

119.6

125.1

126. 5

132.1

92.0

109.8

105.0

113.9

114.7

123.4

119.9

124.1

126.7

132.2

92.2

106.8

105.7

115.0

114.7

123.6

120. 0

127.7

126.7

132.4

93.6

112.0

105.9

115.0

115.2

117.7

120. 2

127. 7

127.4

131.8

95.3

115.0

106.4

120.0

115.5

124.1

120.2

129.3

127.4

132.6

95.4

114.9

107.0

117.9

115.9

121.4

120.6

125. 4

127.7

132.0

95.6

108.5

107.1

119.6

116.1

125.1

120.6

125. 6

127.8

130.7

96.3

113.2

107.1

120. 0

116.1

127.7

121.1

126.1

128.7

131.5

96.5

113.9

108.2

115.7

116.3

127.2

121.2

124.3

129.4

134.2

96.6

102.2

108.7

119.0

116.4

124. 0

121.3

127.4

129.8

137.0

97.1

117.1

108.9

117.2

116.4

126.0

121.3

129.8

130.4

135.0

97.4

112.0

109.1

121.8

116.9

123. 0

121. 4

125.4

131.0

136.4

97.5

119.8

109.6

119.3

117.1

123. 3

121.8

125.8

131.3

133.4

97.6

109.3

109.8

122. 8

117.4

126.5

122.4

130.2

131.6

135.8

99.5

116. 1

110.2

120.4

117.8

126.7

122.5

126.5

131.6

136.1

100.5

113.6

110.2

121.6

117.9

122.5

122.8

126.2

131.8

134.4

101.3

109.2

110.4

122.3

118.0

125.6

122.9

130.8

132.6

139.4

101.5

107.5

111.6

119.0

118.0

126.5

123.6

126. 9

132.8

135.8

101.6

108.6

111.6

122.0

118.0

127.9

123.7

125. 0

133.4

136.9

101.6

115.0

111.6

122.4

118.2

126.2

123. 7

126.4

133.7

137.6

101.7

115.4

111.7

123.7

118.6

125.3

123.7

129.9

134.3

137.6

101.8

113.1

111.7

123.0

118.8

125.6

124.9

132.8

134.4

136.6

SAMPLE 2, OUT 58.1 WEEKS

85.6

106.0

100.7

120.0

111.8

120.4

119.2

125.0

127.1

134.7

86.9

107.3

101.7

115.8

112.4

120.5

119.7

129.1

127.2

133.5

87.9

105.1

101.8

111.6

112.6

126. 2

120. 0

129.3

128.5

136.4

88.8

113.9

103.0

116.6

113.3

120.4

120. 6

129.9

129.7

133.4

90.3

115.3

103.5

115.2

113.5

119.4

121. 0

126.0

130.7

137.6

90.9

103.0

104.5

115.2

113.9

123.8

121.3

126.0

130.9

135.0

90.9

108.3

104.9

115.6

114.4

120.6

121.4

128.5

131.0

134.5

90.9

114.4

105.0

117.2

115.0

125.6

121.9

127.0

131.0

135.3

91.8

105.7

106.2

117.4

115.4

123. 9

122.8

134.1

132. 9

135.4

91.9

112.3

106.3

118.5

115.6

125.4

122.9

127. 9

133.7

136.7

94.7

107.5

107.1

121.8

115.9

127.1

124.0

133.8

138.3

95.0

115.3

107.2

118.9

115.9

127.5

124.6

129.7

133.9

136.4

95.3

113.3

109.1

116.9

116.1

124.0

124. 9

128.1

134.0

137.3

98.6

110.4

109.4

118.7

116.2

125.6

125.0

128.9

134.4

140.6

98.6

116.1

110.7

118.5

117.4

123.3

126.0

133.4

134.6

136.1

99.4

114.8

110.8

124. 0

117.8

123.5

127.0

131.5

136.1

136.7

99.6

116.2

111.1

121. 2

118.2

124.7

127. 0

133.8

141.1

143.1

100.5

118.9

111.7

126.0

118.7

121.9

127. 1

130.9

Table 2. — Length (mm.) of 392 sea scallops when tagged
(Lg) and released at latitude Irl"52' N., longitude 66°23'
W., on Sept. 22, 1957, and when recaptured (Lr) about 1
year later — Continued

SAMPLE

3, OUT 60.7 WEEKS

85.5

106.0

99.3

113.2

108.3

123.3

117.7

122.7

127.1

131.7

90.4

106.8

100.8

114.3

109.7

117.0

119.1

128.8

129.8

131.9

93.0

109.4

102. 1

111.5

110.7

121.2

120.8

127.8

130.4

132. 9

94.8

111.0

102. 1

116.5

110.9

117.2

121. 5

126. 5

133.1

137.6

96.3

114.9

104.8

117.3

111.4

116.8

121.9

126.3

133.3

136.0

97.7

113.9

104.9

118.2

112.9

125.9

123.4

131.4

133.9

137.1

97.8

119.6

105.5

119.8

113.0

119.8

123.9

129. 9

135.4

140. 1

98.0

110.0

106.4

118.1

114.2

126.5

124.6

131.7

135.9

137.3

99.0

106.5

108.2

124.4

116.0

124.0

126.7

130.1

147.3

147.7

99 0

115.7

SAMPLE 4, OUT 64.1 WEEKS

86.2

110.3

99.3

120.8

109.2

123.3

116.4

123.3

125.4

131.4

87.6

107.3

99.7

118.3

109.3

115.5

116.4

125.1

127.5

131.6

88.9

110.9

99.7

118.5

109.9

119.6

117.9

125.7

128.9

130.8

90.2

110.0

100.5

113.1

110.9

120.3

118.4

125.2

129.1

136.5

93.1

117.3

101.2

117.0

111.5

122.9

119.2

125.2

129.2

134.6

93.5

115.6

101.3

118. 1

111.5

123.5

120.5

131.4

129.7

134.4

93.9

113.3

104.1

121. 0

111.6

124.0

121.3

133.6

130.3

132. 5

95.9

114.0

104.3

119.5

111.9

123.0

122. 0

128.5

133.3

140.2

97.4

114.0

105.1

120.7

113.3

122.4

122.5

132. 4

136.6

138.3

97.6

114.3

105.7

121. 5

113.9

122.8

122. 9

128.2

137.9

139.0

97.6

121.8

106.0

118.5

115. 5

119.3

123.4

129.2

138.4

140.1

98.2

113.2

107.6

112.9

115.7

124.1

123.8

12S. 2

143.7

145.5

108.1

108.4

117.4

SAMPLE 5, OUT 66.7 WEEKS

86.8

104.8

104.2

116.2

111.5

126.1

117.9

125.1

128.5

130.1

92.2

117.9

105.7

119.2

112.9

121.1

120.9

130.6

128.6

130.5

93.1

114.5

105.9

115.3

114.2

126.5

121.0

128. 8

129.5

131.0

94.8

117.5

106.7

119.2

114.9

121.7

122. 1

127.7

129.7

131.1

95.1

116.2

107.6

123.3

115.1

120.4

122.3

128.0

129.8

132.7

95.1

117.7

107.8

120.1

115.2

127.5

123.5

127.4

130.3

134.0

98.6

115.3

109.3

120.3

115.3

126.7

124.7

127.7

130.4

136.8

100. 1

113.3

109.4

120.6

116.7

124. 9

125.6

133. 2

136.7

138.2

100.8

116.0

110.2

119.2

116.8

123.9

126.9

132.2

139.3

140.2

100.8

116.8

110.3

127.5

117.2

128.9

127.0

137.5

141.8

143.7

100.9

113.0

110.4

124.2

117.8

125.5

128.2

132.4

149.3

150.1

ANNUAL MARKS ON SHELL OF SEA SCALLOP

307

Figure 11. — -Upper valve of a sea scallop showing seasonal change in color.

We have calculated the length at age for the 4
years following recruitment of sea scallops to the
fishery using both growth-rate equations.

Item

Age

(+1

(+2

(+3

'+4

85.0
85.0

103.7
102.4

116.1

114 .7

124. 3
123.4

129 7

It is clear that the two equations, derived by
different methods, give essentially t lie same re-
sults. We. therefore, have confidence in growth

rates calculated by either method, and that our
methods of locating annual rings are valid.

AGE AT RING FORMATION

It is interesting to note that, despite the strong
check mark put on the shell at time of tagging,
the tags apparently did not inhibit growth. Also,
if we assume that there is little seasonal variation
in the growth rate on Georges Bank, for those
scallops that had been out for about a year, we can
estimate the time of year when the annual ring is

:-;ns

U.S. FISH AND WILDLIFE SERVICE

laid down from the position of the ring on the shell
between the check mark made at time of tagging
and the margin. On this basis, the 1958 ring
appears to have been laid down about 27 weeks
after the date of tagging. This places ring forma-
tion at March 30, just 6 months after October 1,
which is the usual date of spawning by sea scallops

in this area (Posgay and Norman, 1958). The
true age at the time of ring formation in this area
is, therefore, the number of the ring minus one-
half year. There is a possibility, now under
investigation, that the first definable ring, at
about 20 mm., is not laid down during the first
year of life but rather in the second.

Figure 12. — Upper valve of a sea scallop that has been tagged, released, and recaptured,
row points to the nick which was made in the margin at the time of release.)

(The ar-

ANNUAL MARKS ON SHELL OF SEA SCALLOP

309

Table 3. — Age structure and average length {mm.) at time of ring formation in sample of 351 sea scallop shells determined

independently by 2 readers

Number of rings on the shells

Average length

Grand

average

Reader No. 1:
Ring number

21.6
58.3
84.5

20.4
54.6
80.8
95.9

19.6
53.9
79.9
96.0
106.9

19.8
55.4
83.4
99.3
109.9
116.8

19.6
55.2
81.0
98.3
110.3
117.6
123.0

18.0
53.2
81.3
100.9
113.3
122.4
128.1
131.2

17.9
54.7
80.1
95.9
109.2
117.9
125.4
131.5
133.8

19 6

55 0

81 6

97.7

109.9

118.7

125.5

g _

131 3

133.8

Reader No. 2:
Ring number

21.2
56.1
85.8

20.5

53.2
83.5
98.7

20.0
53.8
81.2
98.3
109.2

19.7
55.0
82.5
99.8
111.9
118.6

19.7
54.9
81.2
98.6
110.6
118.4
123.8

19.9

51.5
79.7
98.7
110.5
120.4
126.7
130.1

18.2

54.9
80.8
97.7
109.1
118.4
125.6
131.5
133.5

19.9

2...

54.2

82.1

98.6

110.3

118.9

125.4

130.8

9. .

133.5

OBJECTIVITY OF THE CRITERIA

To test whether our criteria for determining
which annuli were annual rings were sufficiently
objective, a summer assistant, William Evoy of
Reed College, was trained in the reading technique.
He was then given a sample of 351 shells to age
and measure, after which the same sample was
read by the senior author.

The correspondence of results was very good
(table 3). There was disagreement on the num-
ber of rings, but never by more than one, on about
10 percent of the shells and a few additional dis-
agreements as to position of the annual ring.
The growth-rate equations calculated from the
two sets of data were virtually indistinguishable,
as shown in the following formulae:

Z,+, = 37.49 + 0.7384Z,

Z(+1=36.75 + 0.7467Z,

SUMMARY

The shell of the sea scallop, in common with
many other mollusks, bears annual rings but they
are frequently weak and ill-defined or masked by
the presence of other annuli caused by nonannual
phenomena. By using annual marks on the
resilium, changes in shell curvature, changes in

color pattern, weight of the shell, and areas of
attack by boring organisms it is usually possible
to localize the position of the annual rings so that
they can be found by intensive examination.

These methods have been validated by showing
that a growth rate calculated from the annual
rings was almost identical with a growth rate
calculated from the growth of tagged and recap-
tured animals from the same area.

LITERATURE CITED

Dickie, L. M.

1955. Fluctuations in abundance of the giant scallop,
Placopecten magellanicus (Gmelin) in the Digby
area of the Bay of Fundy. Journal of the Fisheries
Research Board of Canada, vol. 12, No. 6, pp.
797-857.
Lindner, Milton J.

1953. Estimation of growth rate in animals by
marking experiments. U.S. Fish and Wildlife
Service, Fishery Bulletin 78, vol. 54, pp. 65-69.
Posgay, J. A.

1950. Investigations of the sea scallop, Pecten
grandis. Third report on investigations of methods
of improving the shellfish resources of Massachusetts.
Commonwealth of Massachusetts, Department of
Conservation, Division of Marine Fisheries, pp.
24-30.

1953. Sea scallop investigations. Sixth report on
investigations of the shell fisheries of Massachusetts.
Commonwealth of Massachusetts, Department of
Conservation, Division of Marine Fisheries, pp.
9-24.

310

U.S. FISH AND WILDLIFE SERVICE

Posgay, J. A., and K. Duane Norman.

1958. An observation on the spawning of the sea
scallop, Placopecten magellanicus (Gmelin), on
Georges Bank. Limnology and Oceanography,
vol. 3, No. 4, p. 142.

Stevenson, J. A., and L. M. Dickie.

1954. Annual growth lings and rate of growth of the
giant scallop, Placoptcten magellanicus (Gmelin),
in the Digby area of the Bay of Fundy. Journal
of the Fisheries Research Board of Canada, vol. 11,
No. 5, pp. 660-671.

Trueman, E. R.

1953a. The ligament of Pecten. Quarterly Journal
of Microscopical Science, vol. 94, part 2, pp. 193-
202.

1953b. Observations on certain mechanical proper-
ties of the ligament of Pecten. Journal of Experi-
mental Biology, vol. 30, No. 4, pp. 453-467.
Walford, Lionel A.

1946. A new graphic method of describing the growth
of animals. Biological Bulletin, vol. 90, No. 2,
pp. 141-147.

ANNUAL MARKS ON SHELL OF SEA SCALLOP

311

DYNAMICS OF A PENAEID SHRIMP POPULATION AND MANAGEMENT

IMPLICATIONS

By Joseph H. Kutkuhn, Fishery Biologist (Research)
Bureau of Commercial Fisheries, Galveston, Tex.

ABSTRACT

In assessing present utilization of a stock of pink
shrimp (Penaeidae) that supports an important com-
mercial fishery in the eastern Gulf of Mexico, the inter-
action of population growth and mortality is critically
analyzed. Estimates of the parameters involved were
secured through a mark-recapture experiment wherein
a biological stain served as the marking agent. The
experiment was oriented in space and time so that ex-
ploitation of the marked population, which initially
consisted of individuals uniform in size, provided
measures of growth and mortality in the parent age
group during and immediately following its transition
from prerecruit to postrecruit status. Throughout the
experiment, the entire stock as well as the marked popu-

lation were heavily fished. Upon examining the ques-
tion of whether or not the fishery's production could be
improved by postponing the start of fishing until the
shrimp reach a size greater than the 70 headless-count
designation now generally viewed as a practicable
minimum, it was noted that expected growth, although
relatively high, would be insufficient to offset sub-
stantial losses due to expected natural mortality.
Even with a moderate increase in growth rate, an
appreciably reduced natural mortality would have to be
indicated before such a move could be considered
feasible. Maximum potential yield in both weight
and value is obtained with the minimum acceptable
size that the fishery currently imposes.

Broadly speaking, the basic goal of biological
research undertaken by the Bureau of Commercial
Fisheries is to gain the best possible understanding
of how fishing and the principal environmental
factors (once they are determined) govern the
size of commercial fishery resources, and hence
the yield of fish and fishery products. Its attain-
ment would, theoretically, enable us to establish
guidelines for maintaining any resource at about
that level where production or, perhaps, economic
advantage is highest. One should not gain the
impression, however, that such a level can be held
static over long periods of time, but recognize in-
stead that it is subject to fluctuation from year to
year in response to an everchanging environment
and thereby presupposes continual readjustment
of fishing intensity.

Utilization is associated very closely with the

Note.— Approved for publication December 21, 1962.

FISHERY BULLETIN: VOLUME 65, NO. 2
774-711 O— 66 2

concept of resource maintenance. In the con
notation of the phrase "conservation of natura
resources," maintenance and utilization are, in
fact, not mutually exclusive. But it is always
likely that long before research can produce a
scheme for effective resource maintenance, it will
provide ad interim some indication of how a re-
source should be best utilized. Fishery research,
which largely embraces the field of population
ecology (including dynamics), becomes most
efficient when it programs for short-term or inter-
mediate as well as long-term objectives. It is
noteworthy that the processes of achieving both
types of objectives very often require the same
basic data.

For nearly as long as Gulf of Mexico shrimp
resources have been exploited, concern has pre-
vailed as to whether they have always been
utilized to best advantage. Many believe that
the minimum size of commercially acceptable

313

shrimp should be increased, that the harvesting of
any age group (or "brood") should be delayed
until, by virtue of a high growth potential, maxi-
mum (or at least a greater) weight or biomass is
reached. Phrased more simply, the question
posed and heretofore not answered satisfactorily
is: At what size per individual should an age
group of shrimp begin to be harvested so as to
realize the maximum yield from that group during
its life span?

This question has important economic implica-
tions and requires that we understand the relation-
ships between, and can measure, the rates of two
concurrent biological processes: (1) Growth, the
increase in shrimp size per individual per unit time,
and (2) mortality, the numbers of shrimp dying
per unit time (particularly due to natural causes).

Over the years, fishery biologists have found
population growth and mortality parameters
highly elusive. Recently, however, as part of its
long-range shrimp research program, the Bureau of
Commercial Fisheries perfected a very satisfactory
process of marking shrimp that now permits
such parameters to be approximated by the useful
mark-recapture technique. The marking system
proving so successful is the stain-injection method.
Menzel (1955) is generally credited as having con-
ceived its use on shrimp; Dawson (1957) as having
substantiated its potential by means of laboratory
experimentation; and Costello (1959, 1964) and
Costello and Allen (1960) as having developed its
large-scale application afield.

This paper first presents the results of a mark-
recapture experiment with a rather well-defined
stock of pink shrimp, Penaeus duorarum Burken-
road, which supports an important commercial
fishery in southwest Florida, the widely known
Tortugas fishery. After documenting the re-
quired estimates of growth and mortality, the
paper then describes their synthesis through a
theoretical yield equation to attempt an answer
to the question stated earlier. In so doing, it
draws in small part on the results of yet another
mark-recapture experiment conducted with the same
species, but for a different purpose, just prior to the
one of primary interest.

Though it was classified as merely preliminary
and expanded efforts were to be scheduled only if
it achieved any reasonable degree of success, the
Tortugas experiment proved successful well be-
yond our somewhat modest expectations. The

quality of the resulting data is reflected in the kind
of treatment they are given here. Such extensive
treatment, regardless of the experiment's outcome,
had not been anticipated in advance.

TORTUGAS MARK-RECAPTURE
EXPERIMENT

DESCRIPTION AND REGULATION OF FISHERY

Lying west of Key West, Fla., reaching little
beyond the 30-fathom contour, and extending not
much farther northward than the 25th parallel,
the Tortugas trawling grounds seasonally ex-
perience some of the most intense shrimp fishing
seen in the Gulf of Mexico (fig. 1). Stimulating
this activity is the appearance of large numbers of
subadult pink shrimp which emerge in closely
spaced surges from the shallow "nursery" grounds
in Florida Bay to the east.1 Although matur-
ing shrimp may enter the fishing grounds at all
seasons, it is in September-March that migrations
are greatest and fishing is heaviest. Practically
all fishing occurs at night when the pink shrimp
is most active and hence most vulnerable. Like
its close relative the brown shrimp, P. aztecus
Ives, this species usually burrows and is therefore
comparatively inaccessible during the hours of
daylight.

Most trawlers operating on the Tortugas and
adjacent grounds are of the characteristic Florida
design (fig. 2). For all practical purposes they
are nearly uniform in size and power, and employ
fishing gear of roughly the same specifications
(Iversen and Idyll, 1959; Kutkuhn, 1962).

The Tortugas fishery together with a lesser one,
the Sanibel fishery, which is centered roughly 100
nautical miles to the north, did not become well
established until the early 1950's (Idyll, 1957). A
question often raised and now being examined is
whether populations supporting both fisheries are
genetically discrete, or whether they are con-
tinuous— even though continuity may prevail
only at widely spaced life history stages. Evi-
dence acquired to date tends to support the as-
sumption made in this study that the Tortugas
fishery largely depends on a stock of pink shrimp
which is essentially separate from that sustaining
the Sanibel fishery (Costello and Allen, 1960;
1961).

I Idyll (1957), Dohkin (1961), and Cummings (1961) should he consulted for
a detailed account of pink shrimp life history.

314

U.S. FISH AND WILDLIFE SERVICE

Prlnc

joi trawling grounds

■■1

Area

Shrimp eoptured for marking

Sitcn

orhed shrimp released

6ounc

ary of state conservation orea

Stole

management area

Site ond number o< recoptures

•

2 to 6

•

7 to 15

16 to 35

•

36 to 70
230 to 240

/;c

Figure 1. — General area in which mark-recapture experiments were conducted. Large numerals (1-4) identify
coastal subareas employed in tabulating fishery statistics. Data shown in subarea 2 refer to the Tortugas ex-
periment (September- December 1961), those in subarea 4 to the Sanibel experiment (December 1960- June 1961).

Annually contributing about 10 percent to the
total Gulf production of shrimp, landings in the
Tortugas fishery reached a peak of 23.6 million
pounds in 1960, having risen from almost a record
low of 12.9 million pounds the year before. The

latter value represented a 44-percent drop from
the previous high of 23.0 million pounds landed in
1958. 2 Since 1956 the fishery has seemingly had

« Source: Gulf coast shrimp data, published monthly by the Branch of
Fishery Statistics, Bureau of Commercial Fisheries, U.S. Fish and Wildlife
Service.

DYNAMICS OF A PENAEID SHRIMP POPULATION

315

Figure 2.— Double-rigged, Florida-type trawlers predominate in the Gulf of Mexico shrimp fleet.

to rely to an increasing extent on small shrimp to
keep production at a profitable level (Kutkuhn,
1962).

Believing that utilization might be improved by
inhibiting the harvest of small shrimp, the Florida
State Board of Conservation established in 1957
what is called a "control" area (Ingle, Eldred,
Jones, and Hutton, 1959, figs. 1-3). This area
was so situated that the preponderance of shrimp
entering the open fishing grounds ostensibly
migrated through it. Fishing was not to be per-
mitted in the control area whenever periodic
surveys disclosed that the shrimp therein were
smaller than the size at which 50 headless and
uniformly sized individuals weigh 1 pound. This
regulatory concept was revised in mid- 1961 when
the Board delineated a permanently closed con-

servation area which incorporated part of the
earlier control area and extended the latter's
boundaries to enclose all of Florida Bay (fig. 1).
Also circumscribed was a less extensive manage-
ment (control) area from which only shrimp of 60
"headless-count" or larger may be taken.

MARKING PHASE

The Tortugas mark-recapture experiment was
designed to take complete advantage of the
physical and regulatory features of the fishery.
Shrimp destined to make up the experimental
population were to be captured, marked, and
released just prior to the onset of heaviest expected
fishing intensity. Concentrations of precom-
mercial-size shrimp moving through the State
management area offered the opportunity to

316

U.S. FISH AND WILDLIFE SERVICE

establish an experimental population from which
could be obtained measures of growth and mor-
tality in the parent population before and during
as well as after its transition from prerecruit to
postrecruit status.

Accordingly, operations using facilities provided
by the Bureau's M/V George M. Bowers got under-
way on September 18, 1961, with the first releases
of marked shrimp being made 2 days later.
Shrimp were captured with small-mesh trawls
hauled for very short intervals of time (frequently
not more than 2 minutes) to minimize injury
caused by compression in the net. To insure that
only shrimp in prime condition entered the experi-
ment, catches were held in tanks of circulating sea
water for periods of at least 12 hours. After all
weak and dying individuals had been removed, the
remainder was sorted so that only those falling
into a specified size range (total length) were
retained for marking. This range was arbitrarily
set using as a point of reference the modal length
of available shrimp, such length having been
determined by sampling catches made at the start
of operations. Graded individuals were then
marked by carefully injecting small quantities of a
0.25-percent aqueous solution of Trypan blue stain.
Groups of marked shrimp were observed for at
least 4 hours before being released, only the most
vigorous individuals at the end of that time being
selected for the experiment. These were released
in lots of 100 at scattered sites and at irregularly
spaced intervals during the marking period by
means of a special release box (Costello, 1964).
This device permitted the experimental shrimp
to be returned directly to the bottom from whence
they came (the depth being about 12 fathoms),
and precluded large-scale losses due to predation
by fishes and birds that would have occurred had
the shrimp been released at the surface. Under-
water movies taken during this operation reveal
that marked shrimp released from the box immedi-
ately burrowed into the bottom, thereby satisfying
the assumption that predation losses were, for all
practical purposes, nonexistent. Because of judi-
cious handling, selection, and release of the experi-
mental material, it is hereinafter assumed that the
total number of marked shrimp reintroduced into
the parent population represented the actual or
"effective" size of the marked population estab-
lished during the marking period.

In the manner just described, an experimental

population of 2,090 individuals was created within
a 4-day period. Figure 1 shows the general loca-
tion of capture and release sites. Measurements
from an accumulation of small samples drawn
each time a group of shrimp was released provided
essential information concerning the population's
length and weight attributes at the start of the
experiment (table 1).

COMMERCIAL FISHING OPERATIONS DURING
EXPERIMENT

Greatly influencing the outcome as well as the
utility of results of experiments like the present
one are the amount and distribution of recapture
effort relative to the distribution of the experi-
mental population. With all other potential
sources of bias inoperative or satisfactorily ac-
counted for, the rate at which marked individuals
are recaptured becomes simply a function of the
probability of recapture.3 An index of this
probability is, logically, the intensity of fishing
or, in a rather restricted area such as is involved
here, the fishing effort. A major problem is that
the fishing effort often does not remain constant
and thereby confounds the probability of re-
capture. It must be assumed at the outset, of
course, that the experimental population soon
reintermingles with and behaves in the same
manner as the parent population (age group) from
which it was temporarily removed.

Detailed information of fishing operations during
the Tortugas experiment was provided by the
Bureau of Commercial Fisheries Branch of
Fishery Statistics which has agents stationed at
major Gulf ports, including Key West, Fort

Table 1. — Sex, length, and weight data from samples of the
marked population at the beginning of the Tortugas experi-
ment, middle of week ending Sept. S3, 1962
[Number in marked population: 2,090. Estimated sex ratio: 60^:409]

Sex

Num-
ber
sam-
pled

Carapace length '

Total length

Total weight

Mean

Range

Mean

Range

Mean

Range

168

110

Mm.
19.2

19.5

Mm.

17. 9-20. 1

18. 5-20. 2

Mm.
90.1
88.9

Mm.
84. 2-94. 1
84. 2-94. 1

5.9

6.0

«.
4. 8-«. 8

Female

5. 2-6. 7

Total

278

19.3

17. 9-20. 2

89.6

84. 2-94. 1

5.9

4.8-6.8

' Carapace length is denned as the straight-line distance from the postero-
most edge of the orbit to the posterior edge of the carapace where it intersects
the iniddorsal line.

3 Throughout this report, "recapture" refers to the marked shrimps' capture
by the fishing gear; in contrast, "recovery" refers to their subsequent detec-
tion in commercial catches (or landings) .

DYNAMICS OF A PENAEID SHRIMP POPULATION

317

Myers, and Tampa, Fla. Estimates of the total
effort expended weekly on the Tortugas grounds
had to be projected from sample interviews (n)
with trawler captains landing their catches at
these ports. The procedure simply consisted of
estimating from the sample data the average
number of hours fished during each fishing trip
and multiplying this by the total number of
trips as determined by a canvass of processing
plant records. Thus, the total hours fished in any
week is given by

A }\J n

X=Nx=- x; x,

n i

i=l,2,3, . . .n

where ./Vis the total number of trips by individual
trawlers to the fishing grounds, x( is the number
of trip-hours fished as reported by the captain of
the i*" vessel entering a weekly sample, and x —

- is the sample estimate of the mean number

of hours actually spent fishing during each trip.
The only difficulty arose when "uninterviewed"
trips (N—n) extended over periods of more
than 1 calendar week. In such cases, fractional
trips for each of any 2 adjoining weeks had to be
designated. These fractions were then summed
together with trips contained entirely within
respective weeks to obtain the weekly totals.
Variances of the sample estimates were also
calculated and, under the assumption of negligible
or constant sampling bias, provided the estimates
of total effort with an index of reliability. Hence

r(x}= n(n-l) (-AT*)

and

a A .

confidence interval (Ar): X±tN\r(r)

where t is the value of the normal deviate corre-
sponding to the desired confidence probability.
The Tortugas experiment lasted about 14
weeks; table 2 gives effort statistics and esti-
tnates, together with total landings, for each
week plus t lie two that immediately preceded the
-tart of the experiment. To provide some indi-
cation of how the effort was distributed on the
fishing grounds, the weekly totals are also appor-
tioned (on the basis of interview data) among three

well-defined depth zones. Landing figures are
not estimates but accumulations of actual catch
weights obtained through a continuing canvass
of all processing plants.

One other matter that will warrant considera-
tion in a later section relates to the stage in age
group development at which the member shrimps'
commercial acceptance becomes complete, or
selectivity no longer constitutes a factor. As
employed here, the word "selectivity" does not
refer to the selective properties of fishing gear
but means, rather, the purposeful avoidance of
shrimp of undesirable size even though they may
be largely vulnerable to the gear in general use.
Such selection is ordinarily accomplished by
sorting catches or by test fishing for aggregations
in which most individuals are of marketable size.

Unfortunately, the minimum marketable size
of shrimp varies within the industry (or according
to State law) from area to area around the Gulf,
and in some localities may be only vaguely
defined (or not stringently enforced). During
the Tortugas experiment the fishery did not
recognize a specific minimum size, with the result
that sorting catches for the purpose of discarding
small shrimp was not practiced. In fact, the
only form of selection evident was the weekly
expenditure of comparatively small amounts of
fishing effort prior to the period in which the
greater proportion of available shrimp reached a
size of about 70 headless-count.

Examination of size (weight) frequency curves
obtained from landings during the study period
disclosed that selective fishing solely for medium
and large shrimp was, practically speaking, in-
operative (fig. 3). It suggested further that
shrimp somewhat below the size designated herein
as the minimum acceptable size (70 headless-
count) were, if not entirely, almost wholly vul-
nerable and actively sought out by a sizeable
though undetermined portion of the fishing fleet.
Figure 3 clearly shows that small (in many
instances, very small) shrimp predominated in
Tortugas catches during the last 15 weeks of 1961 .
This fact lends credibility to the assumption that
bias due to the selective action of the fishing gear
was negligible and that the retrieval of marked
shrimp of a size well below that tacitly set as a
commercial minimum was almost entirely governed
by the probability of a piece of gear encountering
and capturing them, even though such probability

318

U.S. FISH AND WILDLIFE SERVICE

Table 2. — Commercial shrimping

operations

in Gulf of Mexico
September-Decemb

statistical
er 1961

subareas

1-3 {Dry

Torlugas-Marquesas) during

Item

Week ending

9-9

9-16

9-231

9-30

10-7

10-14

10-21

10-28

28.8

22.0

0.16

1, 180±250

35.8

10.8

0.09

2, 760±330

81
21

26.0

5.8

0.09

2, 110±250

31.8

20.1

0.14

2, 800±510

49.7

8.1

0.06

3, 980±290

32.1

6.9

0.08

2, 820±300

26.2

5.8

0.09

920±110

115

32.9

3.1

0.05

3, 780±270

1,180

2,760

2.110

2,600

200

212.2

3,720

260

227.3

2.770

179.9

920

3,780

1
42.1

287.9

301.6

72.8

411.8

Week ending

Item

11-4

11-11

11-18

11-25

12-2

12-9

12-16

12-23

12-30

41.7

12.1

0.08

4. 040±440

206

28.3

3.2
0.06

5.830±480

270

37.3

3.2
0.05

10, 070±630

177

30.7

3.7
0.06

5, 430±440

175

39.9

10.0

0.08

6, 980±730

201

44.4

6.3
0.06

8, 920±650

180

8,060

680

467.3

217

42.1

3.0
0.04

9, 140±480

330

7,820

990

433.1

161

35.9

3.3
0.05

5, 780±380

5,380

320

189.9

Mean number of hours fished per trip (x).

24.0
23.3

0.20

Estimated total effort in hours (X) 2.

1, 610±420
390

11-20 fathoms

3.680

360

365.3

5,600

230

680.2

8,760

1,310

763.7

4,890

540

215.8

6,840

140

240.1

1,190

21-30 fathoms

Percent of total effort in Subarea 3.. .. ._
Total landings'

1
39.0

i Week in which experiment began.

2 0.80 confidence intervals.

• Thousands of pounds (whole shrimp).

was represented in part by purposively selective
effort. It follows that the likelihood of recaptures
being subsequently recovered from commercial
landings had to be presumed essentially constant
throughout the experiment regardless of shrimp
size.

RECOVERY PHASE

Extensive publicity coverage preceded and con-
tinued during the experiment. With the as-
sistance of the Bureau's Branches of Fishery
Statistics and Market News, cooperation in the
retrieval of stained shrimp was solicited through
correspondence, market reports, and personal
interview from all industry segments as well as
from State conservation agencies and the Gulf
States Marine Fisheries Commission. The press,
radio, and television provided additional coverage.
A reward of $2 was offered for the return of any
marked shrimp when accompanied by information
regarding its place and date of capture. Posters
to this effect (fig. 4) were conspicuously placed in
all processing plants adjacent to the area in which
the experiment took place. Close contact with
fishermen and processors was maintained at all
times.

Return of marked shrimp began immediately

with 47 having been recovered before the end of
the experiment's first week, referred to herein as
the "period of release." Fortuitously, the State
management area in which the marked shrimp were
released (fig. 1) was opened to commercial fishing
2 days after the experiment got underway. In
all, 443 or 21 percent of the total number liberated
were eventually recaptured and returned for
verification.4 Daily distribution of recaptures is
shown in figure 5. To facilitate subsequent-
analysis, they are grouped by calendar weeks
(top of fig. 5).

Recovery continued strong for the first 8. weeks,
reaching a peak during the sixth week and then
dropping sharply (fig. 5) . No marked shrimp were
recovered after the 13th week. This abrupt at-
tenuation reflected a real decline in the experi-
mental population since associated recapture
(fishing) effort did not decrease but rose signifi-
cantly. Emigration of marked shrimp from the
range of effective fishing effort appeared negligible
(fig. 1), with no individuals being taken beyond 20
fathoms (only two outside 15 fathoms) or north of
the 25th parallel despite measurable expenditures
of effort at both locations (table 2). In general,

' One marked shrimp returned 3 months after recapture was not included
in subsequent analyses.

DYNAMICS OF A PENAEID SHRIMP POPULATION

319

100

RELATIVE SIZE
SMALL MEDIUM , LARGE

TOTAL
CATCH EFFORT

Woeh ending^SEP 9,196

500

'. «^^ SEP 16

500

\ .

SEP 23*

0
500

SEP 30

500

OCT 7

500

\ # ^___^.« .

OCT 14

500

OCT 21

500

•\._

OCT 28

_ :

500

NOV 4

_ :

500

NOV. 1 1

1 _

500

■^

NOV. 18

u ;

0
500

NOV 25

500

DEC 2

500

DEC. 9

500

DEC 16

;

500

DEC 23

;

500

DEC 30

500

24 MR UNITS

1000s OF L8S (WHOLE)

68+ 67-51 50-41

NUMBER

40-31 30-26
PER POUND (

25-21 20-15

EADLESS)

-1 EFFORT

•

wEEK IN *HiCm EUPERIMEMT 8E0AN

Figure 3. — Weekly commercial catch and effort statistics
from the Tortugas pink shrimp fishery (statistical
Subareas 1-3), September-December 1961.

what little movement was observed for the marked
shrimp during the course of the experiment seemed
to be in a west-northwesterly direction. As will be
shown later, the week in which most marked
shrimp were recaptured (sixth week, October
22-28) coincided with that during which the pre-
ponderance of the experimental population at-
tained the "minimum" commercial size designated
earlier. In other words, selective fishing by a
heretofore undetermined portion of the fishing
fleet ceased to be a factor at approximately this
point.

Slightly less than three-fourths of the marked
returns were detected while handling catches at
sea. Because of the consistently small size of
shrimp taken during the experiment (fig. 3), the
great majority of catches had to undergo complete
processing ashore. Such treatment entailed re-
moving the head of each shrimp by hand, an

Shrimp have been marked with blue and green biological stains to obtain infor-
mation on movements, growth, and rate of horvest. The color appears only on both
sides of the head (in the gills) as shown in the Illustration.

LOOK FOR COLOR HERE

A reword of $2.00 will be paid for stained shrimp when returned with the following
information:

1. Exact place the shrimp was cawaht.

2. Date the shrimp was cawaht.

Notify by mail the U.S. Fish and Wildlife Service. No. I Rickenbacker Causeway,
Miami, Florida, or contact any Fish and Wildlife Service agent at port of landing.
Please include name of vessel with the information submitted.

Figure 4. — Typical poster advertising reward for the
return of marked shrimp. Blue stain was employed in
both the Tortugas and Sanibel experiments.

TOTAL I

RECAPTURED > <- <D *t \n <T
WEEKLY J T <Q f - -

O O ro O O

Period ot reieose.

2 4 6 9 10 12 14
WEEKS AFTER RELEASE

SEP

OCT NOV

1961

DEC

A- Point ot which shrimp reached
minimum commercial size

Figure 5. — Temporal distribution of fishing effort and of
marked shrimp recaptured during the Tortugas experi- *
ment. Vertical bars from the abscissa represent number
recaptured on indicated days. Vertical lines through
points on effort curve define 0.80 confidence intervals for
weekly effort estimates.

320

U.S. FISH AND WILDLIFE SERVICE

operation usually undertaken aboard the fishing
vessel when most of the catch consists of medium-
size or larger shrimp. Regardless of where be-
heading takes place, however, the chances of
detecting marked specimens in the process are
always very good to excellent. Under the con-
ditions prevailing in most processing plants they
are highest. All recovered shrimp not found at
sea by vessel crews were later retrieved by plant
personnel.

So far as is known, only a small fraction of all
landings made within the study period escaped
such close scrutiny, this occurring when landings
infrequently had to be shipped directly to canneries
located on the northern Gulf coast.

SANIBEL MARK-RECAPTURE
EXPERIMENT

Though specifically designed for another pur-
pose, the Sanibel experiment yielded growth data
that proved useful in corroborating comparable
data derived from the Tortugas experiment. By
way of providing a brief description, the former
experiment began about 9 months before the latter
and extended over the period December 1960 to
June 1961. In an attempt to determine the mi-
gration patterns of juvenile pink shrimp as they
leave estuaries in the vicinity of Sanibel Island,
Fla., 32,900 shrimp were marked with Trypan blue
stain and released in Pine Island Sound. Com-
mercial fishermen subsequently recaptured 155
(or 0.5 percent) at the locations indicated in
figure 1.

Individuals making up the experimental popula-
tion were first graded to uniform size though not
nearly so carefully as those selected for the Tortu-
gas experiment. A sample of 463 specimens taken
at the experiment's start revealed a mean total
length and corresponding weight of 75.3 mm. and
3.5 g., respectively. Sexes occurred in the esti-
mated ratio of 46 males to 54 females.

ESTIMATION OF GROWTH
METRIC CONVERSIONS

Solution of the yield equation employed in a
later section postulates that the average growth of
each individual making up the population of
interest be expressible in terms of weight, and that

the average relationship between an individual's
weight and length be firmly established.

Since it is ordinarily impractical to measure pre-
cisely in the field the weight of animals as small as
shrimp, sampled individuals for the most part must
be measured as to length at the sampling site, or
preserved (rarely frozen) and later measured, again
according to some length criterion, at a more con-
venient time and place. Subsequently required in
either case are appropriate means for converting
length to weight units.

Three situations that are met in the course of
studies like the present one, and in shrimp research
generally, may thus be defined. The first entails
reciprocal conversion of the linear size indices
commonly used in shrimp work, viz, total and
carapace length. In this study, for example,
total length was the criterion used to grade
shrimp selected for the Tortugas experiment.
But the sample from which the actual size-range
limits were determined had to be preserved
(formalin) for later measurement under more
favorable conditions. Since the total length of
shrimp so treated cannot be accurately measured
because of the distorting and hardening effects of
the preservative, carapace length, which remains
unimpaired, provides the most practicable index
of shrimp size. The statistical relationship
between total length and carapace length serves
to transform either linear dimension to the other
and proves particularly useful when comparing
the results of research in which the methods of
measurement differ from one study to the next.

The two remaining situations prevail where
interest centers on the transformation of linear
to weight units, i.e., (1) from total length
to total weight when length measurements
can be made at the time of sampling and (2) from
carapace length to total weight when the sample
material must first be preserved.

Over the period August 1960 to January 1961,
and independent of the experiments reported
herein, weight and corresponding length measure-
ments were obtained from slightly more than 1,600
pink shrimp sampled from commercial catches
taken along the east and southwest Florida coast
(Biscayne Bay and the Tortugas-Marquesas area,
respectively). An indication of their statistical
strength in terms of sample distribution by sex
and relative size is given in table 3.

DYNAMICS OF A PENAEID SHRIMP POPULATION

321

TOTAL LENGTH-CARAPACE LENGTH RELATION-
SHIP

A plot of the mean carapace lengths for each
of 28 male and 36 female, 5-mm. total-length
classes suggested that the relationship between
the two attributes could be best described by a
simple exponential (fig. 6). Up to a total length
of about 150 mm. the relationship for both sexes
appears nearly identical and is, for all practical
purposes, rectilinear. Beyond this length, how-
ever, definite curvature indicates that increases

240

220-

200-

w p 140

10 20 30 40 50 60

CARAPACE LENGTH

(mm.)

in carapace length (c) do not keep pace with
increases in total length (I). Note also in the
larger shrimp a marked sex differential in the
total length-carapace length ratio. Thus, for
shrimp of the same total length, females will have
a greater carapace length than males, the difference
increasing with size.

Table 3. — Distribution by sex and relative size of pink
shrimp sampled during 1960-61 in south Florida for
weight and length measurements

Sex

Number of
specimens
measured

RaDge in
total
length

Number of
5-mm.
length
classes

Average
number of
specimens

per class

Number of

classes

with less

than 15

specimens

729
888

Mm.

35-175

35-215

28
36

25
26

Female

Total....

1.617

35-215

FIGURE 6. — Total length-carapace length relationship
in pink shrimp.

For pink shrimp not exceeding 170 mm. total
length (equivalent to 16 headless-count), the
information provided in figure 6 will permit,
graphically or mathematically, reasonably accu-
rate estimation of total length from a known
carapace length. Although precision diminishes
somewhat above this limit, resulting estimates
will still be sufficient for most purposes.

Linear conversions indicated in table 1 and
elsewhere in this study employed the information
given in figure 6.

Weight-Length Relationships

Plots of data categorized as above showed
weight to be a simple power function of length.
Either the fitted curves or equations for total
weight (w) as a function of carapace length
(fig. 7), and as a function of total length (fig. 8) I
may be used to estimate weight from either I
linear dimension with reasonable precision and U
accuracy. Close examination revealed some sea- I
sonal variation in the relationships, but not I
enough to be of practical significance. Sex I
differences are clearly evident in each case with i
the disparity being particularly prominent in the I
total weight-carapace length ratios. Among
-liiin 1 1> having the same carapace length, males, on '
the average, not only possess a greater total ll
length but are heavier than females. It follows, I
conversely, that in individuals of the same total I
length, the males will weigh less than the females M
and have a shorter carapace. These differences |
should be borne in mind whenever metric conver- .

322

U.S. FISH AND WILDLIFE SERVICK

100

PINK SHRIMP

9-/^ = 0 002£2'9

d,-^ = oooir 30"

6 i

| 60

3 rr

< 50

i-
o

_^-^r i i

1 . 1.

18
20

- 40

50
60
68
75

- 100

200
300

20 30 40
CARAPACE LENGTH

Figure 7. — Total weight-carapace length relationship in
pink shrimp.

sions of the types treated here become necessary.

All length-to-weight conversions required in
subsequent analyses are made with the informa-
tion shown in figures 7 and 8.

Of particular interest in the present study is
whether or not shrimp growth is isometric or, more
specifically, whether or not the total weight-total
length relationships derived above conform to the
well-known cube law, viz, w=aP>, where 6 = 3.
Conformation (or lack thereof) should be acknowl-
edged when growth and mortality parameters are
integrated to solve the yield equation referred to
earlier and described in a later section. The fact
that the parameters of the mathematical expres-
sions relating total weight to total length proved
almost identical for both sexes (fig. 8) simplified
somewhat their statistical assessment. Upon
being tested with sexes separate or combined, the
hypothesis of no exponents differing significantly
from 6 = 3 had to be rejected. [For sexes com-
bined— H0: 6 = 3. 00 when in fact 6 = 3.14 — 1=

11.16, compared with <.os (33 degrees of freedom) =
2.04.]

ESTIMATING GROWTH PARAMETERS AND
FITTING CURVES

Recaptures from the Tortugas experimental
population provided some of the best data yet
obtained for describing growth in North American
Penaeidae (table 4). Tn synthesizing these data
for practical application later, a growth differential
between sexes materialized as the only real impedi-
ment, there being no evidence of growth inhibition
by the mark employed. Ideally, growth constants
for both sexes should be treated separately (via
summation methods) in all yield predictions,
particularly since the maximum size attained by
male shrimp appears to fall far short of that
attained by females (re table 3). Whether or not
both sexes have equivalent life expectancies poses
still another argument that would have to be
reconciled. But, to obviate undue complexity
and because breakdown of recapture data by sex

PINK

SHRIMP

= 5 06

x io

/*r --

449

x 10

6^3

TOTAL LENGTH

Figure 8. — Total weight-total length relationship in pink
shrimp.

DYNAMICS OF A PENAEID SHRIMP POPULATION

323

would have resulted in diminished reliability of
sample length and weight estimates, each growth
statistic hereinafter computed and substituted in
yield equations reflects a compromise or "sexes-
combined" situation. Although such statistics
are in a sense artificial, their use is justified in that
they define the average growth pattern within the
experimental population during that period when
the age group represented was enjoying greatest
biomass, was most accessible, and its sex ratio had
not yet begun to indicate a preponderance of
females. Each estimate obtained may be viewed
as lying intermediate between some upper value
for females and a lower value for males.

It follows also that experimental length and
weight data from a sexually heterogeneous popula-
tion yield the most reliable growth-parameter
estimates when the sex ratio of marked recaptures
remains constant throughout the experiment. In
the case of the Tortugas experiment, the sampling
distribution of ratios generated over the period t\ — U
revealed no significant statistical departure when
checked for goodness of fit against the uniform
distribution theorized from the sex ratio established
at the experiment's beginning [x2=12.15 compared
with x2-05 (6 degrees of freedom) = 12.59].

Table 4. — Mean lengths and weights of marked pink shrimp
recaptured during successive weeks of the Tortugas experi-
ment, September- December 1961 (sexes combined)

Week of
experiment

Number
recap-
tured '

Distribu-
tion of
males

Mean
total
length

Mean

we i gilt

Range in
weight

Equivalent
number per

pound
(headless)

2 325

176

2-2

»1

/'( r<-t nt
60
51
54
•17
61
55
42
67
67
100

Mm.
88.8
90.0
92.5
103.9
106.0
109.8
113.1
118.7
123. 2
123.4

5.9
6.1
6.6
9.5
10.2'
11.4
12. 5
14.5
16.2
16.4

■ G.

4. 9- fi. 6

4. 9- 7. 1

5. 5- X. 3

8. 0-10. 2
8.1-11.3
7.5-15.8

10. 1-18. 3

9. 6-17. 6
13. 4-19. 2

123

119

2...

110

3.w...

4...

11..

12 .

130.4

19.5

18. 7-20. 2

» Total numljer of recaptures used for growth computation (422) does not
agree with total number recaptured during experiment (442) because breakage
or other damage precluded carapace-length measurement in somi
mens.

2 Data from 47 recaptures combined with sample data (table I) secured
during period of n I i

* Measurements (nun this specimen excluded from growth computation.

* One other specimen I v) returned 3 months after recapture was tiot in-
included in analysis.

Although comparable growth data contributed
by the Sanibel experiment did nut meet the re-
quirement of constant sex ratio (table 5), their
greater temporal range gave a better indication

324

of the probable shape of the pink shrimp growth
curve. Subsequent plots of mean weights of
marked shrimp recaptured during successive
time increments within each experiment suggested
that von Bertalanffy's (1938) growth-in-weight
equation offered, as it has in a wide variety of
species, the most meaningful and at the same
time the most practical solution to the problem
of mathematically characterizing shrimp growth
(fig. 9). In addition to the exponent b, which is
obtained from the weight-length relationship, the
function itself,

^WM-e-KC-'o))",

contains three parameters that are presumed
effectively constant when describing growth over
the greater part of the shrimp's life span. W.
represents the asymptotic or maximum weight
attained by the average shrimp; K is a coefficient
proportional to the rate of catabolism; and t'0
defines a hypothetical age at which the shrimp's
weight would have been zero had its growth pat-
tern always been the same as that suggested by
the experimental data.5 If growth be assumed
isometric, then b takes the value 3; in the present
case, the estimated value, 3.14, was employed.
For more extensive discussions on the rationale
underlying the von Bertalanffy equation and the
advantages that render it particularly adaptable

Table 5. — Mean lengths and weights of marked pink shrimp
recaptured during successive 4-week periods of the San,ibel
experiment, December 1960- June 1961 (sexes combined)

Month of

experiment

Number
recap-
tured
n

Distribu-
tion of
males

Mean

length

Mean
weight

Range in
weight

Equivalent

numljer
per pound
(headless)

'463
"1

4
39
65
38

6
»1

Percent
46
0
100
38
52
39
33
0

Mm.
75.3
111.7
109. 1
117. 5
123.0
136.1
145.8
157.5

3.5
12.1
11.0
14.1

16.3
22. 5
27. 7
35.2

(1.
1. 8- 8. 9

207

8. 2-13. 8

7. 1-24. 8

. 8. 1-29. 5

14. 4-40. 2

21. 9-32. 5

3 .

1 Indicates number of specimens sampled to determine mean length and
weight of marked shrimp at start of experiment.

2 Data from single recaptures not used in growth computation. One ad-
ditional specimen (<?) recaptured in l-'th month was also disregarded.

s To remind the reader that the estimation of growth parameters from mark-
recapture experiments necessarily involves the translocation of size and time

- the notation t'0 herein replaces the standard <». The latter represents
the true pi. pul. it ion parameter which may be most accurately estimated only
when a reasonably complete series of weight-at-age data for agiven species is
available For all practical purposes, it is assumed that the difference
between (,, and (J,, or bias, is negligible.

Throughout tins paper, the symbols t and In designate, respectively, the
base of, and abbreviation for. the natural or Naperian logarithm.

U.S. FISH AND WrLDLrFE SERVICE

Figure 9. — Growth in weight of pink shrimp. Curves
are fitted to mean weights of marked shrimp re-
captured during successive time intervals of the
Tortugas and Sanibel experiments (sexes combined).
[Open circles indicate weights of single recaptures not
used to fit curves.]

to incorporation in theoretical population models,
the reader is referred to the works of von Berta-
lanffy (1957), Beverton and Holt (1957), Ricker
(1958), and Tomlinson and Abramson (1961).

Approximations to Wa were obtained by first
transforming the von Bertalanffy equation to a
form linear in w)'b and then fitting the linear re-
gression of w)'^ on w]"1. The intersection of the
resulting line with that of proportionality yielded,
upon retransformation, the desired estimates
(Beverton and Holt, 1957, p. 283). In effect, the
intersect signifies the approximate weight at which
the ratio of successive growth increments reaches
unity, i.e., growth is arrested and maximum weight
is attained. The slope of the regression line pro-
vides an estimate of e~K.

A distinct disadvantage of this method when
working with data from mark-recapture experi-
ments is the requirement that weights be obtained
for every one of a reasonably wide range of suc-
cessive, equal-width time intervals. Unfortu-
nately, Wm is quite sensitive to changes in the
slope of the fitted line and therefore has real
meaning only when the marked population that
yielded the data was at all times completely
vulnerable to the sampling (fishing) gear, the sex

ratio of recaptures remained static, and the re-
sulting mean sample weights display consistent
as well as good reliability. Thus, its estimation
from the somewhat inadequate Sanibel data had
to rely on but four pairs of values (from U_ — 16),
whereas*that from the superior Tortugas data was
substantiated by seven pairs (from U — U). Be-
cause of considerably less variation about the
fitted line, the estimate derived from the Tortugas
data is regarded the more stable, and hence the
more meaningful of the two (table 6). When
estimating Wa) there was no suggestion in the
case of the Tortugas data, and only faint evidence
in the Sanibel data, that the fishing gear in gen-
eral use was selective for faster-growing individuals
during the early stages of either experiment.

Table 6. — Pink shrimp growth statistics computed from
mean weights of marked shrimp recaptured during succes-
sive time intervals of the Tortugas and Sanibel experiments
(sexes combined)

Experiment

Season

Dura-
tion

Width of
experi-
mental
time in-
terval, t

Wo,

Tortugas

Sanibel.

Sept. -Dec
Dec-June

Weeks
12
32

Weeks
1
4

•42.0
35.6

0.071
0.339

Weeks
0.68
3.20

1 Equivalent to a size of 17 headless-count.

After adjusting wt and Wa to unity at the be-
ginning (tn) of each series of data, the slope of
the linear relationship

In (W^-wV») = {hx (W'J")+Kt'0}-Kt

provided estimates of K, and the ordinate at which
the regression line intersects In FT„ gave estimates
of t0 (table 6). Substituting these in the von
Bertalanffy equation, theoretical values for wt
were calculated and ultimately defined the curves
depicted in figure 9. It is assumed that the values
for the constant t'0, although based on data of
weight at undetermined age, would have compared
reasonably well with those obtained had the actual
(rather than the relative) age at each tt been
known.

From table 6 and figure 9, it may be concluded
that the results of both experiments are in large
degree mutually corroborative. With the Tor-
tugas results arbitrarily established (on statistical
grounds) as the standard for comparison, Wa is
of the same relative order of magnitude while the

DYNAMICS OF A PENAEID SHRIMP POPULATION

325

growth indices, K, agree surprisingly well (com-
parative K from the Sanibel experiment = 0.339/
4 = 0.085). Weekly growth during the Tortugas
experiment averaged roughly 1.5 g. in terms of
weight and about 3.4 mm. in terms of total length.
From a commercial fisherman's viewpoint, the
experimental data (table 4) reveal that it took 12
weeks for the average shrimp to increase in size
from 123 to 37 count (headless). Observe also
that the minimum commercial size (70 headless-
count) in the marked populations was attained
about 9 weeks following the start of the Sanibel
experiment, and 4K weeks after the Tortugas
experiment began.

AGE AT RECRUITMENT— MAXIMUM AGE

If, as Beverton and Holt (1957) argue, biological
rather than mere empirical significance be attached
to von Bertalanffy's equation and, further, if the
growth pattern as fixed by the constants computed
earlier be assumed reasonably typical of pre- as
well as postrecruit development, then extrapolation
of the curves in figure 9 to the left of t^ should
provide a rough index to the actual ("average")
age of shrimp making up each experimental popu-
lation at the time it was established. Adding
this to the time lapsing between an experiment's
initiation and the attainment of minimum com-
mercial size by its elements gives a measure of
age at recruitment. Fear that the von Berta-
lanffy equation may not adequately describe
growth during the shrimp's earliest develop-
mental stages should not deter pursuit of such an
index. No better approach to solving the vexa-
tious problem of age determination in commercial
Penaeidae has yet been developed.

•In treating accordingly the results of the Tor-
tugas experiment (upon which all subsequent
analyses and discussions will be based), a value
between 10 and 11 weeks was indicated as the
probable age of shrimp released at the experi-
ment's start. When this value is extended by the
4}i weeks the marked shrimp required to reach
minimum commercial size, an approximation of
15 weeks for their age at recruitment is obtained.
Despite the likelihood that this value may not be
too precise, its order of magnitude is quite reason-
able in view of what has been observed in a species
closely related to (and often occurring with) the
pink shrimp, viz., the brown shrimp.

Along the Texas-Louisiana Gulf coast and with

little year-to-year variation in chronology, height-
ened spawning activity in offshore brown shrimp
populations during February and March nor-
mally results in large masses of postlarvae enter-
ing adjacent estuaries during mid-March to
mid-April. Present studies by personnel at the
Bureau of Commercial Fisheries Biological Lab-
oratory in Galveston, Tex., are yielding good
evidence that brown shrimp postlarvae, 8 to 12
mm. long when they reach the barrier island
passes, are on the order of 3 to 4 weeks old.6
Once in inshore waters they grow very rapidly
and begin their seaward migration about mid-
June as subadults of a size just below the 70-
count minimum established above. Thus, the
total lapse in time between hatching and attain-
ment of 70-count size (about 10.5 g.) is roughly
15 weeks, which agrees very well with the value
obtained for pink shrimp from the Tortugas
experiment.

One other growth-associated feature of pink
shrimp hfe history about which the yield equa-
tion employed in a later section requires in-
formation is the maximum age, on the average,
that this species attains. For the common Pen-
aeidae, it has been generally assumed on empirical
grounds that 18 months (78 weeks) is a good
approximation thereto (Kutkuhn, 1962). Re-
cent analyses of weight frequency distributions
in commercial pink shrimp landings indicate,
however, that the lapse between an age group's
recruitment and its disappearance from the
fishery (i.e., its fishable life span) averages about
68 weeks (Kutkuhn, 1962). Hence, upon com-
bining this value with that of the species' average
age at recruitment calculated above, a value of 83
weeks, believed to be a better estimate of maximum
age, is obtained.

ESTIMATION OF MORTALITY

BASIC ASSUMPTIONS

Computationally as well as conceptually, meas-
urement of mortality — especially natural mor-
tality— is without question more intractable
than that of growth and therefore makes greater
demands on experimental data. Moreover, since
the investigator cannot guarantee that the results

• Lindner and Anderson (1956) offer supporting documentation in their
study of the contemporary white shrimp. /* wtifetus, whose postlarvae
Iso estimated to be about the same age when they enter estuaries at
comparable sizes

826

U.S. FISH AND WILDLIFE SERVICE

of even the most carefully executed mark-recapture
experiment will satisfy all theoretical requirements,
he is forced when attempting such measurement to
rely heavily upon certain conditional assumptions
that may or may not be warranted.

Potential sources of bias affecting the accuracy
of mortality estimates anticipated from data
yielded by the Tortugas experiment have already
been discussed. To reiterate, assumptions for
which reasonable substantiation was given are:

(1) No, or only negligible, losses of experimental
shrimp due to rough treatment at release, or to
predation during and immediately after release;

(2) no losses attributable at any time to after-
effects of the mark (dye); (3) little if any move-
ment of marked shrimp from the range of effective
fishing during the experiment; and (4) negligible
loss of recaptured shrimp because of failure to
report them. Information indicating the percent-
age loss due to nondetection was not obtained,
but the manner in which commercial catches were
processed leaves little doubt that the likelihood of
detecting marked shrimp was high (as was the
incentive to do so). Nevertheless, a necessary
assumption is that not only was the number of
recaptured but undetected shrimp low, but that
the ratio of undetected to detected recaptures did
not change during the experiment.

THEORY AND EXPERIMENTAL RESULTS

All present-day theory constituting the frame-
work of what is commonly termed "population
dynamics" has as its point of departure the con-
cept that the average rate of decline in any popula-
tion (fish, shellfish, etc.) is at every instant pro-
portional to population size. This relationship
may be simply expressed by the differential
equation

= -ZN

which, upon integration, gives the geometric
progression

N,=N0e-z' (1)

with common ratio e~z, N0 the initial population
size, and N, the number in the population during
any of a series of equal-width time intervals t.
Two parameters, N0 and Z, characterize the ex-
pression, with the coefficient Z referred to as the
instantaneous rate of total mortality.

The foregoing theorem proves particularly use-
ful in mark-recapture work since the initial size of
a marked population, N0, is almost always known.
In some situations this feature readily permits the
separation of Z into its components, viz., (1)
mortality in the experimental population due to
recapture (fishing) , and (2) losses of marked mem-
bers due to all other causes. These quantities are
symbolized in the following analysis by the nota-
tion F and A', respectively (Beverton and Holt,
1957). Of major interest is the coefficient X,
part of which represents true natural mortality,
hereinafter denoted by the symbol M. Depend-
ing on the acceptability of assumptions concerning
the degree to which marked members are not
prone to loss other than through fishing and natu-
ral mortality, X itself can provide a reasonable
approximation of M.

As revealed earlier (fig. 5), the probability of a
marked shrimp being recaptured varied widely
during the Tortugas experiment. It follows that
the corresponding fishing mortality fluctuated
accordingly, and that the effects of nonuniform
recapture effort would therefore have to be
eliminated before attempting to measure total
mortality, Z, and, ultimately, natural mortality,
M. Two approaches to the satisfactory measure-
ment of Z with recapture data generated under
such circumstances are employed herein, whereas
only a single alternative offered itself as a solution
to the more difficult problem of estimating X
(i.e., M).

The first of the two methods used to determine
Z entailed application of an analytical method
developed for the simple situation where fishing
effort (or intensity) does not change appreciably
during an experiment. Its use here initially re-
quired that, rather than assume within each equal-
width time interval a fixed but, between intervals,
a successively different (i.e., a discontinuous) fish-
ing mortality, the number of recaptures accumu-
lating in every time interval be adjusted to a con-
tinuously uniform fishing effort throughout the
experiment (table 7). Such an approach clearly
infers that had a static fishing effort prevailed,
the pattern of population decline expressed by
theorem (1) — with all bias constant or negligible—
would have been reflected. In other words,
removing the confounding effects of a varying
fishing effort served to eliminate all but that part
of the overall recapture probability that would

DYNAMICS OF A PENAEID SHRIMP POPULATION

327

have diminished predictably as the experimental
population declined. It is noteworthy that ad-
justment of each value in the recapture time-
series under discussion here was itself independent
of time, and hence did not superimpose additional
bias whose presence might further curtail the use-
fulness of mortality coefficients to be estimated
by regression techniques from data already serially
correlated.

Since it was derived specifically to cover the
general case where fishing effort varies throughout
an experiment, the second method, which yielded
estimates of X as well as Z, did not necessitate
any preliminary adjustment of raw data. In
large degree, measurements of Z by both tech-
nicpues proved mutually confirmatory.

Table 7. — Unadjusted and adjusted numbers of marked pink
shrimp recaptured during successive weeks of the Tortugas
experiment, September-December 1961

TRANSITION

[Number liberated (No) = 2,090

Week of
experiment

Number
recaptured

Distribu-
tion of
males

Estimated

total fishing

effort '

Number
recaptured

per 1,000

hours'

fishing effort

Log

adjusted

number

recaptured

In n'

184

Percent
55
51
54
47
61
55
42
67
67
100

Thousands

of hours
2. 11±0. 23

2, 80 1 0. 52

3. 98±0. 30

2. 82±0. 30
0.92=fc0. 11

3. 78±0. 20

4. 04±0. 43

5. 83±0. 47
10. 07±0. 62

5. 43±0. 43

6. 98±0. 73
8. 92±0. 65
9. 14±0. 48

22.3
24.3
11.1
5.3
15.2
48.7
9.2
4.1
0.6
0.2
0.0
0.0
0.3

3. 105

3. 190

2.407

1.670

2. 721

3.886

2.219

1.411

-0 511

-1 609

-1.204

1 0.80 confidence intervals.

Subdivision of the Experiment

* Preparatory to mortality estimation, plots of the
adjusted Tortugas recapture data revealed a
distinct but not unexpected discontinuity in the
pattern of exploitation during the experiment
(fig. 10). Prior to its fifth week, in which most
members reached a size acknowledged to be the
commercial minimum, the experimental popula-
tion experienced a measurable amount of pur-
posively selective fishing. Not until the beginning
of the experiment's sixth week can it be presumed
that recruitment to the "commercial" population
was effectively complete. Most interest attaches
to the experiment's second phase since estimates
of fishing mortality between the points of com-
plete recruitment to and virtual disappearance of

328

0 w 60-

s I

jf so
a. '■>

1 §30-

• <

»- SELECTIVITY

5 S

3 4 I 5 6 7 8

Figure 10. — Mortality of pink shrimp. Curves are fitted
to numbers of marked shrimp recaptured during suc-
cessive weeks of the Tortugas experiment (September-
December 1961) and adjusted for nonuniform fishing
effort. [Number liberated (N„) = 2,090.]

the marked population from the fishery (i.e., from
h to ti0), and natural mortality just prior to and
over the same period (i.e., from tt to tl0), are
included among the major objectives of this
study.

The experiment may therefore be conveniently
subdivided into two phases arbitrarily separated
by a brief (1-week) interval of transition. They
are: (1) A period in population development when
the fishery exercised moderate selectivity — the
partially exploited phase, which was characterized
by varying degrees of purposive as well as gear
selectivity ; and (2) a period of nonselectivity — the
fully exploited phase, during which every popula-
tion member was vulnerable to all operating causes
of mortality.

Total Mortality During Partially Exploited Phase

Proceeding from theorem (1), which, upon trans-
formation to logarithmic form, becomes linear in
In iV,and t, Beverton and Holt (1957, pp. 185-191)
give in terms of the recaptures themselves a com-
parable expression intended for use with marked
populations subjected to a uniform fishing (re-
capture) effort. Thus, making appropriate
substitutions,

dn
di

=FN,=FN0e-iF+x"

and. ultimately,

In n2=ln ni — (F+X)r

(2)

U.S. FISH AND WILDLIFE SERVICE

where nu n2, . . . nt refer to the number of marked
individuals recaptured during the first, second,
. . . rth time interval t, respectively; T=ti+i — tt
( = 1 week) ; F and X are the instantaneous co-
efficients of reduction of marks due, respectively,
to fishing and to all causes other than fishing; and
(F+X)=Z. It follows from expression (2) that
a linear regression of the natural logarithms of
successive numbers of recaptures on time gives
estimates of In «; and Z.

Fitting a regression to the logarithms of Tor-
tugas recaptures grouped by weeks and adjusted
for nonuniform fishing effort (viz., In n\ through
In n'3, where the prime indicates an adjusted
value) yielded an estimate of 0.76 for Z, the only
parameter of interest during the experiment's
initial phase. Figure 10 shows that the regression
enjoyed a good fit.

Obviously, a measurable amount of (selective)
fishing effort contributed to the total mortality
value so obtained, though by far the greater share
of this value is presumed attributable to natural
causes. Only a very minor part is believed due to
the "other-loss" factors defined earlier. There is
moreover, no statistical evidence of any differential
vulnerability of sexes during the partially exploited
phase. Despite the slower growth noted for males,
the sex ratio of recaptures never departed signifi-
cantly from that observed at the start of the experi-
ment (table 7). In summary, a small amount of
fishing activity during the experiment's first phase
was sufficient to demonstrate an apparently high
corresponding rate of natural mortality, which, as
will be shown later, continued well into the second
or fully exploited phase. Here it became associ-
ated with the relatively high rate of fishing
mortality established at the moment recruitment-
was completed.

Mortality During Fully Exploited Phase

After plotting the logarithms of the adjusted
numbers of shrimp recaptured during the first 5
weeks of the Tortugas experiment's fully exploited
phase, and observing that they, too, all fell nearly
in a straight line (fig. 10), computation of their
linear regression on time [equation (2)] gave a first
estimate of Z=1.39 for the instantaneous co-
efficient of mark reduction due to all causes.

Attempts to subdivide the resulting Z into its
fishing mortality and "other-loss" components

proved impractical, however, when recapture data
adjusted for varying fishing effort were substi-
tuted in techniques implicitly designed for un-
adjusted data generated by a uniform effort.
Inspection of the basic equations involved (Bever-
ton and Holt, 1957, p. 190, equations 14.15 and
14.16) reveals that the soundness of F and X (or
M) estimated therewith may be influenced not only
by the size of Nn (or any specified equivalent), but
also by variation in the relative magnitude of the
antilog of In ni (or its counterpart), where the
latter value is derived by means analogous to
equation (2). It will be recalled that initial
treatment of the recapture data entailed their
being grouped on a weekly basis, and then adjusted
within each time unit for nonuniformity of fishing
effort between units by a factor equal to the re-
ciprocal of the quantity (/fX10~3), with/, repre-
senting the overall effort in hours expended on the
fishing grounds during the ith weekly interval
(table 7). Subsequent difficulty stems from the
arbitrary nature of the attenuation index, 10-3,
which must be selected so as to yield adjusted
recapture values having an average order of mag-
nitude moderately close to that of the unadjusted
values.

Whereas analysis of recapture data so adjusted
provides [through expression (2)] a good estimate
of the total-loss coefficient Z=(F-\-X), such sub-
jective treatment imparts bias of unknown degree
to the values for F&nd A' when these are delineated
by the equations mentioned above. This bias will
be proportional to the value of 7?t as estimated by
expression (2), and, accordingly, to the relative
size of the adjustment index employed. The real
problem, however, lies in not being able to specify
satisfactorily the relationship between N0 and
the estimated initial value of the recapture time-
series based upon adjusted data, as contrasted to
that between A^ and the corresponding value of
the time-series involving unadjusted data.

Drawing support from the fundamental theorem
stating that over a given time interval r, fishing
mortality is proportional to fishing effort (or
intensity), i.e., Fr = cjT, Beverton and Holt (1957,
p. 192) derive solely in terms of recapture and
related effort values a useful equation which
furnishes — independent of A^ — an estimate of
the other-loss coefficient X, regarded herein for
the reasons outlined earlier as a close appro xima-

DYNAMICS OF A PENAEID SHRIMP POPULATION
774-711 O— ©6 3>

329

tion of M. This equation is given by

T, L \nr+lfrJ

i_m \ (cfr+1+X)(l-e-Wr+x)r,) /J

where r signifies the width (in weekly units) of
experimental time intervals r or r+1, 71 identifies
the number of recaptures in the same intervals,
and c denotes the average coefficient of propor-
tionality relating fishing mortality to fishing
effort, jT.

Equation (3), accounting inherently for varying
fishing effort, is linear in j, and a logarithmic ex-
pression (left side) corresponding to the ratios in
successive time intervals of the numerical abun-
dance of marked individuals composing the experi-
mental population. Accordingly, simple regres-
sion procedures involving at least two iterations
lead to fairly good estimates of c and X, the slope
and y-intercept, respectively. The latter value
may be viewed as a measure of the average total-
loss rate that would have prevailed during the
experiment in the absence of any fishing activity.

Use of expression (3) assumes that bias intro-
duced by the practical need to treat fishing effort
as a discontinuous function of time is negligible.
Its application to appropriate recapture data and
corresponding values of effective fishing effort
gave, after three iterations, estimates of c=0.171,
X=0.55, and average F=0.96 for the fully
exploited phase of the Tortugas experiment (fig.
11). Interestingly, the resulting value for Z=
(F-fA') = 1.51 compared quite favorably with the
preliminary value calculated earlier, viz, Z= 1.39,
differing on the order of but 9 percent. Relevant
statistics are presented in table 8. Note here the
incorporation of effort data slightly modified from
those used earlier to obtain the preliminary esti-
mate of Z. The decision to subject to analysis
only those measurements of effort expended in-
side 20 fathoms was prompted by the observation
that none of the 252 marked shrimp retrieved
during the period of interest (table 8) was re-
captured beyond this range. Such adjustment
seemed necessary to minimized the likelihood of
violating, in terms of the experimental population
and that portion of the fishery's overall activity

2.0-

z
o

I-
<t

=cjr+x (3) a

9
en

FULLY EXPLOITED
PHASE

Slope = c = O.I7l
Intercept = X = 0.55

0 5

EFFECTIVE FISHING EFFORT

~T~~
10

(f)

Figure 11. — Estimating the other-loss coefficient A' using
equation (3) of text. [Refer to table 8 for description
of data and associated statistics.]

directly associated with it both spatially and
temporally, the functional relationship between
fishing mortality and fishing effort (or intensity)
stated above.

Transformation of estimated F and X to cor-
responding weekly rates of reduction in marks
resulted in values of 0.62 for that due to fishing,
and 0.42 for that due to all other causes (see
Ricker, 1958, p. 25, for discussion of relationships).
These results, while indicative of greater mortality
pressure on parent shrimp populations than had

Table S. — Statistics employed to estimate with equation (8)
of text the other-loss coefficient X for the fully exploited
phase of the Tortugas experiment

[Resulting F values are given in the last column; c = 0.171]

Week of
experi-
ment

Rank
in time-
series

Width of
experi-
mental
time
interval

Number

re-
captured

Esti-
mated
effective
fishing
effort i

Left

side of

equation

(3)

Esti-
mated
fishing
mortality

F=c/

2
3

4
5

Weeks

1
1
1
1
2

184

Thou-
sands
of hours
3.78
3.68
5.60
8.76
11.73

Ln units
1.683
0.725
1.642
1.996

0.65

0.63

0.%

1.50

9-10

2.01

1 Treated here as synonymous with fishing intensity which, in broader peo-
Eraphieal application than is here neccssiry, is explicitly defined as fishing
effort per imii area; data represent only ih it innumi of eiTort expended on
the Tort uc. is fishing grounds inside t he l'i) f.tthom contour (re table 2).

330

U.S. FISH AND WILDLITE SERVICE

been widely spectulated, are not unreasonable
when one considers the species' high reproductive
potential, short life expectancy, gregarious habits,
and, presumably, its sensitivity to environmental
fluctuations. Such characteristics, as they con-
trol population development, are not atypical of
Arthropoda in general.

Returning to the matter of discontinuity in
temporal distribution of recaptures during the
Tortugas experiment (table 7, fig. 10), observe now
that its further reconciliation is possible. The
value obtained for X, 0.55, which is henceforth
assumed for the reasons noted earlier to have been
practically all due to natural causes, is readily
contained in the total-loss coefficients estimated
for both partially and fully exploited phases, viz,
0.76 and 1.51, respectively. If natural mortality
is presumed to have been effectively constant
through the transition period, then the difference
in residuals (fishing mortalities, F=0.2l versus
7^=0.96) may be immediately attributed to cessa-
tion of selective fishing accompanied by an abrupt
rise in fishing rate upon completion of recruitment.
It appears that had the low rate of recapture
established during the partially exploited phase
continued, subsequent computations would also
have led to an estimate for X (hence M) compa-
rable to that determined from existing data for the
fully exploited phase.

That the instantaneous rates of mortality do not
remain constant over extended periods of time but
diminish with age is suggested by a small number
of marked shrimp having been recaptured late in
the experiment. Note in figure 10 that their cor-
responding logarithm fell far to the right of the
line fitted to those of adjusted numbers of recap-
tures made earlier in the experiment.

In summary, the foregoing results are inter-
preted to reflect exclusively conditions in that age
group of shrimp represented by the experimental
population, and hence should only be applied with
great caution in other fisheries, or to other age
groups at different seasons. Every age group (as
herein defined) is but one of a succession of groups
that may overlap several seasons. Each is there-
fore likely to be subjected at every stage of de-
velopment to different levels of exploitation as well
as to changing ecological conditions, with the high
expectation that mortality parameters will vary
accordingly.

YIELD IN WEIGHT AS A FUNCTION OF
AGE (SIZE) AT RECRUITMENT

To answer the fundamental question posed
earlier, it remains now to express the interaction
of population growth and mortality in terms of
expected yield when age (or size) at recruitment is
varied over a wide range of values. Thus, so that
the commercial return from a particular age group
(or, in general, all age groups combined) will be
maximal, at what average age of shrimp, under the
conditions of observed growth and mortality,
should harvesting begin?

THEORETICAL POPULATION MODEL

A satisfactory answer may be provided through
application of any one of several mathematical
population models, or analogs, which have been
developed to facilitate study of the dynamics of
open, self-maintaining biological systems (e.g.,
Watt, 1956; Beverton and Holt, 1957; Ricker,
1958) . Notwithstanding its possible shortcomings,
all of which are thoroughly discussed at appro-
priate stages in its derivation, the simple model
developed and applied by Beverton and Holt
(1957, pp. 35-38 and 309-327) was chosen for the
purposes of this study because it offered the most
straightforward solution to a practical problem.

Deterministic in nature, i.e., growth and mor-
tality are presumed effectively constant from
recruitment onward to the end of the species
fishable life span, the expression for the shrimp
population's mean weekly biomass over this period
is given by

0„e

-nK(l'-l0)

P'»=R*-M'WS F+M+nK

(1-

■(F+M+nK)\

where F and M are, respectively, the coefficients
of instantaneous fishing and natural mortality;
Wa, K, and t0 are the growth parameters defined
earlier; R represents the number of shrimp re-
cruited weekly to the fished population; tp> is the
age, corresponding to the minimum commercial
size referred to above, at which recruitment is no
longer influenced by selective fishing; \=t\ — tp>
indicates the population's fishable life span (t\
being the species mean life expectancy) ; and
p=tf,' — tp designates an interval during which
some recruitment occurs because of selective
fishing but population decline is mainly attrib-
utable to natural causes (t„ indicating the age at

DYNAMICS OF A PENAEID SHRIMP POPULATION

331

which shrimp become liable to selective capture
but, generally speaking, have not yet attained
commercial acceptability) . In practice, for a given
set of conditions, p is usually negligible and tP' and t„
may be considered equivalent. The remaining
notation arises from the need, during the model's
development, to expand the exponential term of
the von Bertalanffy growth equation.
Thus, if we let 6=3,

--WJ\-e

-Ka-t„)\b

o>)"

may be algebraically transformed to

wt=wa'22nne-nKl'-,i>

71=0

where the appropriate coefficients of the binomial
expansion are

Qo= + l, fii=-3, 02=+3, 03=-l

with n taking the values 0, 1,2, and 3. Although
earlier analysis of the weight-length relationship
suggested that growth in pink shrimp is not truly
isometric, use of the foregoing model assumes, for
practical purposes, that it is. Actually, the minor
effects of a departure from isometry should be
taken into account by appropriately varying W*>,
but failure to do so here does not lessen the
validity of later findings.

From the biomass equation just postulated, it
follows that an expression for the mean weekly
yield of the fished population may be represented

--FP

And since R, the recruitment, is the only one
of the parameters describing Piv that is not
ordinarily amenable to measurement, further
modification results in

R R afy>F+M+nK

(l-e-<F+M+»m) (4)

hereinafter referred to as the expected yield in
weight per recruit.

DETERMINATION OF YIELD MAXIMUMS

By varying t„,, and hence p and X, curves of
yield as a function of age can be generated with

332

equation (4) for fixed values of the remaining
parameters. The process obviously entads prior
establishment of some absolute minimum value
for tp, this value corresponding in subsequent
analyses to a size below which all shrimp are not
only commercially unacceptable, but also incom-
pletely vulnerable to the gear in common use.

Yield Curve for Observed Parameter Values

We have, from the Tortugas experiment and
other sources, the following values for the indicated
parameters :

M=0.55 <i=0.68 week

2^=0.96 <x=83 weeks

K=0.07 t„= 15 weeks7

W„=42.0g.

Recall also that \=t\ — tp. and p=tp, — tp. Sub-
stituting these in equation (4) and solving it for
each of not less than nine carefully spaced values
of tp., the yield curve farthest to the left in figure 12
was obtained. It is immediately apparent from
this figure that in a population whose development
is governed by growth and natural mortality of the
magnitude observed for the Tortugas pink shrimp
population, peak biomass is attained somewhat
before, rather than after, the average shrimp
reaches a size equivalent to the present commercial
minimum. Growth, although relatively high in
contrast to that determined for a variety of species
supporting other commercial fisheries, evidently
cannot compensate (to man's economic advantage)
for losses accruing to a high natural mortality.
Nor is postponement of full-scale exploitation
indicated unless reduced environmental effects
can be expected to result in a markedly lower
natural mortality. Under observed conditions,
delaying exploitation until the shrimp reach a
greater initial size would indeed result in a negli-
gible gain in yields of so-called premium shrimp,
but only at the expense of a significant reduc-
tion in the total yield of all sizes.

Yield Curves Theorizing Lower Levels of Natural
Mortality

Of the parameter estimates obtained in this
study, by far the firmer and at the same tune the
least subject to wide temporal variation are those

7 Age roughly corresponding to the minimum commercial size of 70 headless -
count.

U.S. FISH AND WILDLIFE SERVICE

-CORRESPONDING NUMBER-PER-POUND EQUIVALENTS
(Headless)

10 £

30 40 50

AGE AT RECRUITMENT ijt/)

{ Weeks)

Figure 12. — Yield in weight per recruit against age at
recruitment for different levels of natural mortality (M)
in a population of pink shrimp. [F=0; 96, A"=0.07;
PP„ = 42.0 g. ; * indicates an observed as contrasted to
a hypothetical value.]

describing growth. In contrast, greater variation
would be expected for natural mortality since it
may be readily conceived ,as the more sensitive
to and hence the more likely of the density-
dependent parameters to reflect even the most
subtle of environmental vagaries. In other words
the potentialities for growth in the individual are
largely predetermined within rather narrow limits
by the characteristics of the species; those for
natural mortality, which are enhanced through
great prolificness, largely by the environment.

With this in mind, additional curves were
generated in like manner for four hypothetical and
successively lower values of the natural mortality
coefficient (fig. 12). These illustrate very clearly
what happens when, with respect, to some economic
standard /„, natural mortality becomes in-
creasingly compatible with growth. For any
magnitude of exploitation (F), maximum yields
will always occur at higher levels and at more
advanced recruitment ages as natural mortality
establishes itself at lower and lower levels. Under
the growth restrictions imposed here, postponing
initiation of exploitation would not be justified
unless the observed natural mortality rate were
on the order of 0.10 or less. It may be argued
now that even if the observed value for M (0.55)
constituted a gross overestimate of the true natural

mortality, the associated error would have had to
be rather large before the general conclusion just
reached could be viewed with suspicion. The
present example also shows that with a natural
mortality of 0.05 (which is untenably low for
shrimp), the highest yield is obtained when age at
recruitment is increased to about 23 weeks, this
corresponding to a shrimp size of roughly 31-35,
headless-count. Dashed portions to the left of tp
arbitrarily designate the likely order and shape of
the yield curves for that part of the hypothetical
population not yet possessing economic worth.

Effects of Variation in Rates of Growth and Exploitation

To illustrate how changes in the critical factors
of growth and fishing mortality influence the yield
curve's shape and the position of its maximum
point, curves for selected (hypothetical) parameter
values are compared with those derived above for
observed values. If yield is described as a func-
tion of age at recruitment for varying rates of
growth (fig. 13 A), it will be noted that the effect
of a higher rate of growth than that observed is
an increase in amplitude of the yield curve and a
shift in its maximum point to the left, with what-
ever recruitment size is designated as the standard
minimum remaining the same as before. In other
words, every shrimp reaches the smallest ac-
ceptable size at an earlier age. Conversely, at a
given level of natural mortality, a lower rate of
growth tends to decrease curve amplitude and
move the point of maximum yield to the right,
the minimum marketable size again remaining
fixed but being attained at a later age.

Exercising care to judge each new set of condi-
tions on its own merits, it appears that increased
rates of growth such as postulated in figure 13A
would still not be sufficient to justify any advance
of recruitment age where a high natural mortality
prevails. At a low mortality level, an advance of
recruitment age is indicated only when concurrent
growth is also of a low order. Hence, for a fixed
natural mortality, successively higher rates of
growth would merely dictate a retrogression in
recruitment age (but not size) if maximum yield is
to be achieved. This relationship implies no
change in minimum acceptable size at recruitment
but, instead, as in the observed situation where low
growth rate complements high natural mortality, a
greater overall yield by the age group involved
during its fishable life span.

DYNAMICS OF A PENAEID SHRIMP POPULATION

333

By comparison, changes in the level of fishing
may be expected to produce only relatively minor
differences in both the position and height of yield
curve maximums (fig. 13B). The revelation that
the magnitude of fishing (F) is actually of little
concern when deciding at what age or size to begin
harvesting a resource in order to achieve maximum
yields should not create the impression that fishing
mortality has no significance at all. Although
maximum utilization of a domestic shrimp resource
is the issue under discussion here, the fact remains
that resource maintenance is still the overriding
objective of shrimp research. As pointed out
earlier, the matter of recruitment age or size is at
this point largely one of economics. Yet to be
answered is the question of how much (in contrast
to what size) shrimp may be harvested and still
have sufficient residual to maintain the resource at
the highest level consistent with projected environ-
mental conditions. In effect, rather than inquir-
ing as to the optimum tp>, we should perhaps be
asking: What is the optimum F?

Employing commercial fishery statistics, a prior
analysis of the Tortugas pink shrimp stock gave
rise to speculation that a decline in production over
the period 1956-59 was attributable more to poor
utilization of supplies than to too intensive fishing
and hence improper maintenance of the stock
(Kutkuhn, 1962). The observation was made that
increasingly heavy exploitation of new recruits, as
they enter the fishing grounds and before their
average growth rate reaches a maximum, appeared
to have systematically reduced annual biomass.
Although this conclusion seems to be in conflict
with the findings of the present study, it must be
stressed that the earlier analysis was necessarily
cufsory due to certain data inadequacies and that
it attempted to generalize over a long period <>f
time and a variety of conditions. In contrast, the
results reported here represent a well-organized
effort to acquire the information needed to answer
specifically the question posed. They are there-
fore quite explicit where the others were not, and,
accordingly, merit much greater attention and
could even be put to interim use.

The present findings do not, however, constitute
the final solution to the stated question. As did
those of the first analysis, they only reflect the
accumulation of more and better data, and merely
serve as one of several anticipated stepping stones
toward an unassailable objective.

30-

X
0.

—

1-
z

20-

. ■

ID-

M = 0.05
■M = 0.55

20 -

111

15 -

F = 0.96

AGE AT RECRUITMENT (4»)
( Weeks )

Figure 13. — Yield in weight per recruit against age at
recruitment for observed and hypothetical levels of
growth (K), fishing mortality (F), and natural mortality
(A/) in a population of pink shrimp. [In plate A,
F = 0.96, Wm =42.0 g., and the ordinate through tf = 15
weeks refers, in terms of corresponding shrimp size,
only to the curves for A' = 0.1)7; in plate B, A'=0.07 and
We =42.0 g.; * indicates an observed value.)

YIELD IN VALUE AS A FUNCTION OF AGE
(SIZE) AT RECRUITMENT

Perhaps more meaningful to the entrepreneur is
an indication of the size at which harvesting should
commence so that total shrimp production will
enjoy highest possible value. Necessitated by
consumer demands, a well-known characteristic of
the Gulf coast shrimp industry is the gradation of
ex-vessel price according to the size of shrimp
landed and sold. Knowledge of the price-size
relationship may be used to advantage in de-
termining where, in different growth and mortality

334

U.S. FISH AND WILDLIFE SERVICE

situations, the curve of yield value on recruitment
age reaches a maximum.

VALUE IN RELATION TO SIZE

For the purposes of this study, particular atten-
tion was given the price structure for pink shrimp
landed at Key West, Fla., during the Tortugas
experiment, September to December 1961 (table
9) . A plot of mean price on whole-weight equiva-
lents for each of 11 size (headless-count) categories
suggested that price could be treated as a logarith-
mic function of weight (fig. 14). The empirical
relationship proved to be satisfactorily described
by an equation of the form

p = a+b\n [\n w], w< 10

where p signifies the price per pound, w is the cor-
responding weight on an individual-shrimp basis,
and a and b denote constants. Note that the ex-
pression has been rendered discontinuous at a
shrimp weight of slightly more than 10 g., which
corresponds to the minimum commercial size of
70 headless-count recognized earlier, and which
commanded the lowest price then in effect (fig. 14).
Dealers accepting them paid the prevailing min-
imum rate (30 cents per pound) for all smaller
shrimp.

Having established a reasonably acceptable
expression for the basic relationship between
market price and individual shrimp weight, it was
then possible to develop one relating the latter
variable to corresponding shrimp value (fig. 14).

Data generated in the process served the needs of
subsequent analyses.

VALUE AS A FUNCTION OF TIME

Since shrimp value increases predictably with
weight, a corollary is that it behaves similarly with
respect to time. Thus, simple transformation of
weight to value units results in a temporal distri-
bution of points which may be empirically defined
by the growth equation employed in a previous
section. By treating the Tortugas experimental
data (table 4) accordingly, estimates of the con-
stants in the regression of value on time were
computed. The counterparts of Wa and K,
respectively, F«, = 4.8 cents approximated the
shrimp's maximum attainable value, and Kv=0.0S
represented an index of the rate of value decrease;
t0; remained fixed at 0.68 week, the value em-
ployed above in the description of growth in
weight. When fitted to the experimental obser-
vations, the resulting expression for shrimp weight
in terms of value as a function of time yielded a
curve over the range of values 0.5 to 5.0 cents
(per shrimp) closely comparable to that given by
the corresponding expression for growth in weight.

DETERMINATION OF YIELD-IN-VALUE
MAXIMUMS

After appropriate substitutions were made for
the above growth-in-value constants, solution of
equation (4) for various recruitment ages (£„,) at
each of four levels of natural mortality {M) per-
mitted construction of the desired yield-in-value

Table 9. — Weekly ex-vessel prices paid for pink shrimp landed at Key West, Fla., 1961
[Values are in cents per pound for headless shrimp graded by sample (box) count] J

Week ending

Size category (Number per pound— headless)

68-72

61-67

56-60

51-55

46-50

41-45

3fr40

31-35

26-30

21-25

15-20

Sept. 16

32
31
27
28
28
23
23
26
29
29
32
32
32
32
32
34

40
36
31
34
34
29
29
32
35
35
38
38
38
38
38
40

41
41
41
41
41
36
36
39
42
42
45
45
45
45
45
47

50
46
46
46
46
41
41
44
47
47
50
50
50
50
50
52

51
51
51
51
51
46
46
49
51
51
54
54
54
54
54
56

57
56
56
56
56
51
51
54
56
56
58
58
58
58
58
60

59
61
61
61
61
54
56
59
61
61
62
62
62
62
62
64

64
66
66
66
66
61
61
64
65
65
67
67
67
67
67
69

69
71
71
71
71
66
66
69
70
70
72
72
72
72
72
74

74 ■

79
81

Oct. 7

14 .

21 _..

25..

Dec. 2

16....

29 4
10.5

35.3
11.4

42.0
12.6

47.3
13.8

51.5
15.3

56.2
17.0

60.5
19.2

65.5
22.1

70.5
26. 1

75.5
32.5

80.5

Whole- weight equivalents (g.)

41.7

1 Source: Market News Service, Bureau of Commercial Fisheries. U.S. Fish and Wildlife Service.

DYNAMICS OF A PENAEID SHRIMP POPULATION

335

NUMBER -per-POUND EQUIVALENTS (HEADLESS

WEIGHT of WHOLE SHRIMP

(g.)

< Commercial Size

Figure 14. — Ex-vessel price (p) against weight (w) of pink
shrimp landed at Key West, Fla., during September-
December 1961. Also shown are the expression for con-
verting price to value (v) on an individual-shrimp basis,
and the resulting plot of value as a function of shrimp
weight. In the upper left-hand corner, the value per
shrimp in cents is graphed as a function of price per pound
in the same units.

-CORRESPONDING NUMBER -PER-POUND EQUIVALENTS
(Heodless)

AGE AT RECRUITMENT U/l
(Weehs)

Figure 15. — Yield in value per recruit against age at
recruitment for different levels of natural mortality in a
population of pink shrimp. [F=0.96; A% = 0.08; Va
= 4.8 cents (per shrimp); a, indicates an observed as
contrasted to a hypothetical value.]

curves (fig. 15). Upon comparing these with the
yield-in-weight curves shown in figure 12, the
most noticeable (though not necessarily significant)
difference is seen in the relative positions of their
maximum points. Unless natural mortality is
extremely low, highest economic yield from a
given age group during its fishable life span
clearly occurs when exploitation begins as soon as
the average shrimp attains commercial acceptance.
In all but those circumstances where extraordi-
narily low natural mortality operates, no advance-
ment of the recruitment age is indicated. This
implies, of course, that the relationship between
price and size holds relatively static.

Of interest is the general observation that, in
situations where postponement of exploitation
may be in order, maximum economic yield can be
expected at a recruitment age (or size) slightly
lower than that suggested for maximum biological
yield. Figures 12 and 15 for M=0.05 illustrate
this very nicely. Note that the yield-in-weight
curve (fig. 12) reaches its highest point at a
recruitment size of about 31-35 count (headless),
whereas the yield-in-value maximum occurs
roughly at a headless-count somewhere between
36 and 40 (fig. 15). This difference is of appreci-
able biological magnitude and can be largely attrib-
uted to the somewhat higher rate of growth in terms
of value (k„=0.08 versus #=0.07). To reiterate,
at levels of natural mortality known to be well
within the range of expectation, the total yield of
a given age group during its fishable life span will
be maximal only when fishing begins at the mini-
mum marketable size. Postponement to a larger
initial size would engender economic loss.

SUMMARY

Measures of growth and mortality in a popula-
tion of pink shrimp obtained simultaneously by
the mark-recapture technique permitted critical
examination of the interrelationship of these
parameters in assessing present utilization of the
resource.

Of 2,090 carefully graded, precommercial-size
shrimp injected with blue dye and released in late
September (1961) at a point on the periphery of the
well-known Tortugas (Florida) fishing grounds,
443 (21 percent) were returned during the ensuing
3 months. Recapture (commercial fishing) effort
was closely surveyed throughout this experiment

336

U.S. FISH AND WILDLIFE SERVICE

and then used to remove the effects of its uneven
distribution from subsequent mortality estimates.
Results of an earlier mark-recapture experiment
performed with the same species but in an adjacent
area and for a different purpose corroborated
growth-parameter estimates from the Tortugas
experiment.

After the various metric relationships used to
convert length to weight units were documented,
the von Bertalanffy growth function was fitted to
the mean weights (sexes combined) of marked
shrimp recaptured during successive, equal-width
time intervals characterizing each experiment.
The more meticulously executed Tortugas experi-
ment yielded for the function's parameters the
values: W7„ = 42.0 g.; J£=0.071; and ^=0.68
week. Weekly growth in weight during the rec-
tilinear phase of the observed growth pattern
averaged 1.5 g., which corresponded to a length
increment of about 3.4 mm. In terms of com-
mercial count size, the average experimental
shrimp required 12 weeks to increase in size from
123 to 37 headless-count. Minimum commercial
size (70 headless-count) was reached approxi-
mately i% weeks after the experiment began, and
at an estimated age of 15 weeks. The life expect-
ancy of the pink shrimp was assumed on the basis
of other studies to be about 83 weeks.

The Tortugas experiment had to be subdivided
into partially exploited and fully exploited phases
before fishing and natural mortality could be
calculated. Rates of total mark-loss during both
phases were estimated by regression techniques
from recapture data grouped by weeks and adjust-
ed for nonuniform fishing effort. Separation of the
value obtained for the fully exploited phase into
its fishing and natural mortality components, F
and M respectively, proved impractical, however,
when attempts were made to apply mathematical
procedures designed specifically to accommodate
unadjusted recapture data generated by a constant
fishing effort. Difficulty arose from an inability
to evaluate satisfactorily the absolute size of the
experimental population at the start of its fully
exploited phase. Subsequent measurement of F
and M by a procedure independent of the initial
size of the marked population's second phase, and
inherently accounting for varying fishing effort
throughout, yielded estimates of 0.96 and 0.55
respectively- Their transformation to weekly

mortality rates gave the corresponding values
0.62 and 0.42. Notwithstanding statistical limita-
tions, these observations draw attention to the
fact that at least in some areas, certain age groups
(or broods) of commercial shrimp may be sub-
jected to rather rapid deterioration from artificial
as well as natural causes.

After substituting therein observed and hypo-
thetical values for the parameters of growth and
mortality, a relatively simple yield equation was
solved for each in a series of selected age-at-recruit-
ment values. With 15 weeks (corresponding to a
size of 70 headless-count) established as the
absolute commercial minimum age and thereby
serving as the point of departure, the resulting
curves of yield on age at recruitment clearly
showed that unless the expected level of natural
mortality falls well below that observed, post-
ponement of fishing until shrimp reach a greater
initial age (or size) is not justified. Observed
growth, although comparatively high, cannot offset
concurrent losses due to the substantial natural
mortality that seemingly prevails when shrimp
availability is at a maximum. Delaying the start
of harvesting woidd subsequently result in slightly
greater catches of shrimp in the larger size cate-
gories, but only at the expense of an appreciably
diminished overall catch.

Even more convincing were the results of a
similar analysis in which weight and hence the
growth function's parameters were expressed in
terms of value. For any level of natural mortality
(observing the restriction imposed by the absolute
commercial minimum presently in effect), maxi-
mum yield in value is attained when fishing com-
mences at a shrimp size perceptibly below that at
which maximum yield in weight would be expected.

The questions tentatively answered by this
study have far greater implications from an eco-
nomic than from a biological standpoint. Still of
great concern is the problem of resource mainte-
nance. We are unquestionably in a better position
to judge when, in the development of any age
group, the harvesting of shrimp should begin so as
to obtain maximum production therefrom. But
it remains for us to evaluate that level of fishing
which, for a given set of environmental conditions
ami for the shrimp resource as a whole, is most
conducive to our ultimate objective: maximum
equilibrium yield.

DYNAMICS OF A PEXAEID SHRIMP POPULATION

337

ACKNOWLEDGM ENTS

The successful outcome of the Tortugas experi-
ment must in large part be attributed to the
unstinting efforts of those responsible for its
implementation and completion. Acknowledg-
ment is especially due Thomas J. Costello who
guided the experiment's marking and recovery
phases; credit for assistance in all aspects of
the field work is extended to Bureau and industry
personnel alike. The author also appreciates the
assistance rendered by Charles H. Lyles, Jr. and
George W. Snow, Branch of Statistics, who
expedited the availability of certain commercial
fishery statistics employed in the analysis. Special
thanks go to Kenneth N. Baxter for his painstaking
computation of estimates of fishing effort.

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Lindner, Milton J., and William W. Anderson.

1956. Growth, migrations, spawning and size distri-
bution of shrimp Penaeus setiferus. U.S. Fish and
Wildlife Service, Fishery Bulletin 106, vol. '56,
pp. 553-645.
Menzel, R. Winston.

1955. Marking of shrimp. Science, vol. 121, No.
3143, pp. 446.

RlCKER, W. E.

1955. Handbook of computations for biological
statistics of fish populations. Fisheries Research
Board of Canada, Bulletin No. 119, 300 pp.

Tomlinson, Patrick K., and Norman .1. Abramson.

1961. Fitting a von Bertalanffy growth curve by
least squares. State of California, Department of
Fish and Game, Fish Bulletin No. 116, 69 pp.

Watt, Kenneth E. F.

1956. The choice and solution of mathematical
models for predicting and maximizing the yield of a
fishery. Journal of the Fisheries Research Board
of Canada, vol. 13, No. 5, pp. 613-645.

338

U.S. FISH AND WILDLIFE SERVICE

STUDY OF LOSS AND DELAY OF SALMON PASSING ROCK ISLAND

DAM, COLUMBIA RIVER, 1954-56

By Robert R. French, Fishery Biologist (Research), Bureau of Commercial Fisheries, Seattle, Washington,
and Roy J. Wahle, Fishery Biologist (Management), Bureau of Commercial Fisheries, Columbia Fishery
Program Office, Portland, Oregon

ABSTRACT

To determine loss or delay of salmonids in passing
Rock Island Dam on the Columbia River, and whether
such loss or delay was associated with the right bank
ladder, salmon were tagged and released both above and
below the dam in 1954-56. They were subsequently
observed passing through the fishways and recovered at
upstream points. Most tagged fish released below the
left and right bank fishway returned over the left, cor-
responding closely with the choice of ladders made by
the untagged populations. Point estimates of sockeye

salmon losses ranged from 0 to 42 percent. Tagging
results (one season only) on spring chinook salmon
indicated a loss of fish released below the right bank
ladder, but no loss when total tag returns from below
and above dam releases were compared; data failed to
show that the dam caused losses of summer chinook.
Tagged salmon released below the dam were delayed
2 to 4 days. Altering the right bank fishway may cause
more fish to use it, but there is no clear evidence that
such alterations will reduce overall loss or delay.

Rock Island Dam, completed in 1934, was the
first dam built on the Columbia River. It is
about 450 miles above the river's mouth in central
Washington (fig. 1). A fishway was built at
each end of the dam to pass anadromous fish and
in 1936 a third was added near the middle of the
dam to pass salmon observed congregating there.
These ladders were the pool type, 20 feet wide,
with a gradient of 1 to 10.

The dam was modified during 1951-53 by in-
stalling regulating gates in the spillway channel
increasing the forebay elevation approximately
12 feet (fig. 2). Six new generating units were
added in the powerhouse (located on the left side
of the dam). These modifications necessitated
changing the fishways to meet the new forebay
level, and fish attraction flow was increased at the
lower end of the left (looking downstream) ladder
to counteract the effect of increased flow from the
turbine units. Although fishery agencies re-
quested changes at the lower end of the right lad-

Note.— Approved tor publication May 26. 1964.
FISHERY BULLETIN: VOLUME 65, NO. 2

der to provide better entrance conditions and ad-
ditional attraction flow, nothing was done at the
time. The entrance of the right ladder at three
different water levels is shown in figure 3.

The Federal Power Commission, in granting
a license amendment for the modification of
Rock Island Dam, reserved the right to require
altering the lower end of the right ladder if sub-
stantial evidence were presented that such alter-
ations or modifications were required for effective
conservation of fish life resources of the Columbia
River. Any such altering was to begin before
Dec. 1, 1960.

The size of anadromous fish runs passing Rock
Island is shown in table 1. Fewer of the fish
have used the right ladder since the dam was
modified. During the period 1936-52, for ex-
ample, the counts of salmon and steelhead at
the three ladders were distributed as follows:
Left ladder, 47. S percent; center ladder, 22.5
percent; right ladder, 29.7 percent. For the
period 1953-56 (after modification of the dam),
the counts were these: Left ladder, 73.7 percent;

339

center ladder, 11.6 percent; and right ladder,
14.7 percent.

This report describes tagging details and the
results of experiments at Rock Island Dam to
determine whether the dam caused loss or delay
to these runs, and whether loss or delay was
associated with the failure of fish to find and use
the dam's right bank fishway.

Table 1. — Chinook and sockeye salmon and steelhead
trout counted at Rock Island Dam, 1933-56 '

Year

Number of fish counted

Chinook

Sockeye

Steelhead
trout

1933

5,668

7,115

16, 305

7,290

5,133

5,795

11,206

9,512

2,507

6,833

11,129

3,364

5,699

9,981

11,717

7,083

12, 353

10, 348

18, 752

20, 121

31,080

33,283

25, 658

25, 085

40, 737
2,227
14,013

16, 500
15, 089

17, 095
19, 591
27, 093

963
16, 340
17, 522
5,035
7,148
45, 030
79, 831
84, 184

18, 600
50, 134

101,826
114, 349
151,747

91,234
155, 055

92,443

1,055

1934

1935

1936

1937

2,373

1938

2,399
5,425

19392...

1940

1941

1942

3,693

1943

1944

1945

1946

1947

1948

2,360
2.470

1949

1950

1951..

3,121

2,883
4,001
5,406
3,141
1,540

1952

1953....

1954

1955

1956

i Silver salmon (O. kisulch) averaged about 60 fish per year during this
period.

' Grand Coulee Dam blocked upriver migration commencing this year.

METHOD OF TAGGING

Preliminary experiments on tagging and meth-
ods of catching salmon were performed in 1953
followed by full-scale experiments in 1954 through
1956 on chinook {Oncorhynchus tshawytscha) and
sockeye salmon (O. nerlca). We planned to tag
steelhead trout (Salmo gairdneri) but too few
(17 to 32 each year) were captured and tagged for
subsequent analysis.

Salmon were trapped at the upstream edge of
the counting boards within the left and right
fishways and at the upstream outlet of the left
ladder. (Earlier attempts to catch quantities of
fish for tagging below the dam were unsuccessful.)
The trapped fish were transferred to tank trucks
and hauled to the tagging sites located approxi-
mately 1,000 feet below the dam on each side of
the river in 1954 and 1955. In 1956, tagged sal-
mon were released off the downstream face of the
dam close to the left or right ladder. The fish

Grond Coulee Dam

Leavenworth
Hatchery

Rock Island
Dam

Figure 1. — Columbia River watershead between Rock
Island and Grand Coulee Dams.

were lowered to water level in canvas bags filled
with water (fig. 4). Forebay tag releases were
from a trap located at the left ladder exit, and at
sites on both sides of the river about 1 mile above
the dam.

Various tag colors or shapes were used for the
experiments at Rock Island Dam (fig. 5). Tags
applied in the forebay differed from those used
below the dam. Serially numbered plastic disks
in combination with plastic bars formed one series
of combinations, and serially numbered plastic
disks with vinyl tubing and vinyl-coated nylon
formed another series used below the dam. These
were attached to each fish by nickel pins inserted
through the body just below the dorsal fin. All
tags were applied in pairs so that the same color
or kind of tag showed on both sides of the fish.
During 1954-55, the salmon were tagged while
held in canvas-lined, cradle-type boxes. In 1956,
the boxes were filled with water and the salmon
were held under water during tagging.

Fish counters at the dam identified and recorded
the tags as tagged fish crossed the counting boards.
Display boards containing all tag samples were

340

U.S. FISH AND WILDLIFE SERVICE

Figure 2a. — Rock Island Dam before modification.

placed in the counting rooms for reference but
counters were not told of the tag applied each day.

Upstream tag recoveries were made from spawn-
ing ground surveys, at fish hatcheries, and from
fish counters' observations at Tumwater and
Zosel Dams (fig. 1). As different colors and com-
binations of tags were used for each experiment, a
tag observed on a live fish provided the same infor-
mation as an actual recovery, except for the
identity of the particular fish. Therefore, up-
stream tag recoveries include both visual observa-
tions of tags and actual recoveries.

To determine mortalities at the dam, we ana-
lyzed and compared the percentage tag returns at
Rock Island from releases below the left and right
bank ladders; for upstream tag returns we com-
pared recovery ratios from the different release
areas above and below the dam. In addition,
percentage tag returns from the two release areas
below the dam were compared by date of tagging
and by volume of water flow at Rock Island. To
determine delay we computed the elapsed day-out
(number of days between tagging and subsequent

tag observations) periods of tag returns at Rock
Island; for upstream returns we computed the
difference in day-out periods for releases above and
below the dam.

ESTIMATION OF TOTAL UPSTREAM
RECOVERIES OF TAGGED SOCKEYE

Upstream tag recoveries and observations for
the 1954-56 individual sockeye experiments at
Rock Island are given in table 2. The numbers of
tagged fish released are given by date, location, and
age group. Releases at the four locations in the
vicinity of the dam were designated as follows:
below dam, left bank; below dam, right bank;
above dam, left bank; above dam, right bank.
The two age groups represented in the releases of
tagged fish were 3-year-old sockeye, recognized by
their small size, and sockeye over 3 years old.
Most of the fish in the latter group were 4 years
old; hence, this group is designated as 4-year-old
sockeye.

The recoveries from each release lot are given by
area of recovery above the dam: (1) Tumwater

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

341

.«**■£

Figure 2b. — Rock Island Dam after modification.

Dam on the Wenatchee River; (2) Zosel Dam on
the Okanogan River; (3) Okanogan River spawn-
ing grounds above Zosel Dam; and (4) all other
areas combined.

In addition to the recovered tagged fish, nu-
merous tagged sockeye were observed, but not
recovered, in the recovery areas. These could be
assigned to tagging date and release location,
because different color combinations of tags were
used for different release date-location combina-
tions. They could not be individually assigned
to age groups, however, hence, it is necessary to
estimate the age composition of the tagged fish
observed.

Spawning ground surveys of the Columbia
River tributaries above Rock Island Dam indi-
cated that 3-year-old sockeye migrate only to the
Okanogan system, where they are found in vary-
ing numbers and proportions. On the basis of
these surveys, together with the absence of re-
coveries of tagged 3-year-old sockeye in recovery
areas 1 and 4, it is reasonable to assume that all the

tagged fish observed in recovery areas 1 and 4
were 4-year-old sockeye.

The age composition of the tagged fish observed
in recovery areas 2 and 3 can be estimated from
proportions of 3-year-old sockeye in the recoveries
from areas 2 and 3. Multiplying the proportions
of 3-year-old sockeye in the recovery samples by
the number of tagged fish observed provides
estimates of the numbers of 3-year-old sockeye
among the tagged fish observed. The numbers
of 4-year-old sockeye among the tagged fish
observed are obtained by subtraction. Table 3
shows the estimated numbers of 3- and 4-year-old
sockeye observed in recovery areas 2 and 3.

In a number of instances, tagged sockeye
recovered at Zosel Dam (recovery area 2) and
released again after being checked for tag number
and tag color were recovered a second time on the
spawning grounds above Zosel Dam (recovery
area 3). It is likely, therefore, that other tagged
fish recovered or observed at Zosel Dam also were
observed or recovered in recovery area 3. It is
likely also that some tagged fish observed on the

342

U.S. FISH AND WILDLIFE SERVICE

spawning grounds subsequently were recovered.
Such double recoveries or observations result in a
tagged fish being counted two or more times in
recovery areas 2 and 3.

To estimate the number of tagged individuals in
the recovery-observations totals, we use the
following expression:

S=R2+R»+02+Oz-Ra

-f <«-(£) (t)(E-+0'

Where, for each tag release group (age-release area-
year combination),

i?2 = number of tagged fish recovered at Zosel Dam
R3= number of tagged fish recovered in area 3

02= number of tagged fish observed at Zosel Dam
03= number of tagged fish observed in area 3
R23= number of tugged fish recovered at Zosel Dam
and also in area 3

The first negative term corrects for double
recoveries of tagged fish; the second negative term
corrects for recoveries in area 3 of tagged fish
observed at Zosel Dam; the last negative term
corrects for observations in area 3 of tagged fish
recovered or observed at Zosel Dam. The quan-
tity, S, is referred to as the estimated total single
recoveries.

Table 4 shows the recoveries, double recoveries,
observations, estimated duplicate recovery-obser-
vations, and estimated total single recoveries for
each release group.

Table 2. — Sockeye salmon tagging data at Rock Island Dam

[19541

Number released ■

Number recovered

Number observed, age

3-year

4-year

undetermined

Area of recovery

Area where observed

Below dam, left bant:

July 16 .._

44
73
135
131
110
135
125
31
18

(2 42)

(7 66)
(27 108)
(21 110)
(20 90)
(62 73)
(73 52)
(18 13)
(14 4)

0
0
0
0
0
0
0
0
0

2
2
0
17
6
0
1

0
0
1
2
0
1
2

0
0

0
0
0
0
0
0
0
0
0

2
5
10
9
2
5
3
2
0

3
4
3
3
1
1
0
0
0

3
6
5
5
0
4
0
0
0

0
0
0

1
1

1
3

10
18
22
10
6
1
0

4
19
9
7
13
16
0
2

0
0
0
0
0
0

2
0

0
0

Aug. 6

Total

802

(244 558)

Below dam. right bank:

July 1

126

139

(0 1)

(0 7)

(0 14)

(38 88)

(4 21)

(37 46)

(17 46)

(43 46)

(82 57)

(43 32)

(25 18)

(1 3)

(0 1)

0
0
0
0
0
0
9
0
0
0
0
0
0

0
0
0
2

0
2
4

5
7
2
2
0
0

0
0
0
0
0
1
1
1

0
0

0
0
0
0
0
0
0
0
0
0
0
0
0

0
1
0
2

1
0
3
3
1
1
0
0
0

0
0
0
3

0
0

2
0
0
0

0
0
0
2
0
1
0
1
3
0
0
0
0

0
0
0

1
1

0
0
0

0
0
1
7
2
10
6
5
8
1

0
0

0
0
0

23
2

18
9

17
2
1
0
0

0
1
1
1
0
0
0
0
3
0
0

21. _._

27.. __

Aug. 3

5 „.

10 _.

12..

17 _

Total

670

(290 380)

Above dam, left bank:

July 23

70
32
30
13
8
2
2

(14 56)
(8 24)

(10 20)
(4 9)
(2 6)
(0 2)
(1 1)

0
0
0
0
0
0
0

0
0
1
0
0
0
0

0
0
0
0
0
0
0

0
1
0
0
0
0

0
0
0
0
0
0
0

1
0
0
0
0
0
0

0
0
0
0

0
0

11
5
7
1
0
0
0

8
1
4
0
0
0
0

0
1
0
0
2
0
0

6 .

13 _

Total

157

(39 118)

Summary:

1,472
157

(534 938)
(39 118)

0
0

56
0

0
0

50
5

22
0

14
1

113

156
13

9
3

See footnotes at end of table.

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

343

Table 2. — Sockeye salmon tagging data at Rock Island Dam — Continued

11955]

Number released '

Number recovered

Number observed, age

Area and date

3-year

4- year

Area of recovery

Area of

"ecovery

Area where observed

Below dam, left bank:

July 21 - ..

59
111
95
92
50
79
71
22

(0
(3
(4
(4
(3
(3
(11
(4

59)
108)
91)
88)
47)
76)
60)
18)

0
0
0
0
0
0
0
0

0
0
0
0

0
3

0
0
0
0
0
0

0
0
0
0
0
0
0
0

9
14
24
20

4
26
12

2
2
1
3
0
4
4
1

8
9
5
4
3
3
2
0

0
1
0
1
1
0
2
0

1
3
2
1
0
6
3
3

0
0
0
0
0
1
0
0

2
1
1
1
0
1
3
0

Aug. 2

Total

579

(32

547)

111

Below dam, right bank:

July 19

67
55
45
78
73
76
24
101
41
37

(1
(2
(4
(5
(3
(5
(5
(14
(5
(9

66)
53)
41)
73)
70)
71)
19)
87)
36)
28)

0
0
0
0
0
0
0
0
0
0

2
0
0
0
0

0
0
0
0
0

0
0
0
0

0
0
0
0
0
0
0
0
0
0

4
2

6
10
12
4
4
16
6
5

1
3
0
6
2
4
1
5
1
0

11
9
3

4
8
9

2
0

0
1

0
0
2
3

1
0
0

2
1
2
3
3
4
1
1
2
3

2
2
0
0
1
1
0
0
0
0

1
0
1
3

0
2

0
0

26 .

28 .

Aug. 2 - _

9 _. __

11.

Total

597

(53

544)

Above dam, left bank:

July 21 ...

61
60

64
8
17

(1
(3
(1
(1
(5

60)
57)
63)
7)
12)

0
0
0
0
0

8
5
14

1
1

4
2
3
0
0

8
5
1
1
0

1
0
2
0
0

7
2

5
0
0

0
0
0
1
0

0
2
1
1
1

Aug. 3

5 - -

12 _.

Total _

210

(11

199)

Above dam, right bank:

July 20

44
49
50

(1
(2
(3

43)
47)
47)

0
0
0

1
3
5

1
0

5
5
6

0
1
0

5
3
0

0
0

1
1
1

27 .

Total

143

137)

Summary:

1,176
353

(85
(17

1,091)
336)

0
0

180
38

39
16

82
31

12
4

41
22

7
3

19
8

Above dam total

11956]

Below dam, left bank:

July 13 -- - --

90
75
91
47
41
49

(1 89)
(15 60)
(38 53)

(9 38)
(19 22)
(27 22)

0
0
0
0
0
0

0
0

0
0
2

0
1
1
0
1
0

0
0
0
0
0
0

10
26
8
4
2

0
1
0
0

5
5
1
1
1
0

2
0
0
1
0
1

7
2
2
2
0
3

1
0
2
0
2
2

2
2
0
3

19.

Aug. 1.

0
1

1
0

Total

393

(109 -Mi

Below dam, right bank:

July 10

24
20
80
75
%
33
30

(0 24)
(0 20)
(4 76)
(34 41)
(30 66)
(15 18)
(24 6)

0
0
0
0
0
0
0

0
0

0
2

0
0
2

0
0

1
1

0
0
0
0
0
0
0

2
0
10
15
27
4
2

0
0
0
0
0
0
0

0
0
5

2
2
0
0

1
0
0
0
0
0
0

1
0

2
I
0

0
0

1
0
0

5
9
1

Aug. 2

0
0
0
0
0
0

Total

358

(107 251)

Above dam, left bank:
July 11

41
98
90
73
35
19
46

(0 41)
(21 77)
(36 54)
(26 47)
(19 16)

(5 14)
(25 21)

0
0
0
0
0
0
0

0
0

1
1

0
0
0
2

0
0
0
0
0
0
0

3
30
15
21
4
5
4

0
0
0
0
0
0
0

5
3

3
0
0
0
0

0
0

5
5
6
2
1
0
0

0
0
1
0

0
0
0

1
1
0

Total..

402

(132 270)

Above dam, right bank:
July 18

(3 16)

Total

(3 16)

Summary:

751
421

(216 535)
(135 286)

0
0

7
4

123
85

2
0

22
2

5
5

23
3

32
3

Above dam totals

1 Figures in parentheses represent the number of 3- and 4-year-old fish, resi>eetively, making up the total.
■ No tagged fish were released above dam, right bank, in 1954.

344

U.S. FISH AND WILDLIFE SERVICE

Table 5 contains a summary of releases of tagged
sockeye by age group and release area and recov-
eries at Tumwater Dam, in the Okanogan River,
and in other areas combined. The estimated total
recoveries of 3- and 4-year-old tagged sockeye in
the Okanogan system also are shown.

DETERMINATION OF MORTALITIES
AT ROCK ISLAND

If there were a substantial loss of fish below Rock
Island Dam, whether caused by a failure of fish
to find a fish ladder or for other reasons, there
should be a greater upstream recovery of fish
tagged and released above the dam than of fish
similarly tagged and released below the dam.
Mortalities also should be reflected by the number
of tagged fish passing the dam compared to the
number released. We found, as shown later, that
the fish counters' records of tagged fish passing
Rock Island Dam from releases below the dam did
not give completely reliable data on fish mor-
talities (assuming unaccounted-for tags as mortal-
ities caused by the dam) . Results of the upstream
tag recovery comparisons are presented first,
followed by the results obtained at Rock Island
Dam.

RETURNS FROM, UPSTREAM

Sockeye

Analysis of the tagging data to estimate mortal-
ities is complicated by the presence of different
races of sockeye in the tagging groups, by different
age groups, and by the unequal effort expended

recovering tags from different races and age
groups. The sockeye run separates a short
distance above Rock Island Dam, with some fish
going into the Wenatchee River system and some
fish up the Columbia River to the Okanogan River
system. A few sockeye show up at the Entiat
and Winthrop fish hatcheries and in Icicle Creek
below the Leavenworth fish hatchery. As stated
previously, 3-year-old sockeye are restricted to the
Okanogan system and 4-year-old fish are found in
all areas. We could effectively observe or recover
all tagged fish passing Tumwater Dam on the
Wenatchee River while on the way to spawning
areas. In the Okanogan system, however, tag
recoveries were made during stream surveys of
the spawning areas and sampling at Zosel Dam on
the Okanogan River, Thus, the recovery effort
for tags on fish in the Wenatchee and Okanogan
systems was not equal. Adding to these compli-
cations is the very probable loss of some tagged
fish due to a tagging mortality or to straying.

Taking a simple approach, we have estimated
the mortality rates from the ratios of the recov-
ery proportions of tagged fish recovered from
above- and below-dam releases. We made the
following general assumptions: (1) The chance of
recovering tagged fish is the same regardless of
tagging date and tagging site, (2) racial propor-
tions in the tagging lots are the same for the
different areas of release, and (3) the chance of a
tag recovery or observation is independent of tag
type or color.

Table 3. — Estimated numbers of 3- and 4-year-old tagged sockeye salmon in recovery areas 2 and 3, by year and release area

Recovery Area 2

Recovery Area 3

Year and release area

Number
recovered

Per-
cent
3's

Number
observed

Estimated
numbers
observed

Estimated
totals

Number
recovered

Per-
cent
3's

Number
observed

Estimated
numbers
observed

Estimated
totals

3's

4's

Total

3's

4's

3's

4's

Totals

3's

4's

Total

3's

4's

3's.

4's

Total

1954

Below dam, left bank

Below dam, right bank--
Above dam, left bank

1966

Below dam, left bank

Below dam, right bank..
Above dam, left bank...
Above dam, right bank . .

1956

Below dam, left bank

Below dam, right bank__

Above dam, left bank

Above dam, right bank..

24
0

5
5
0
0

4
5
0

7
0

17
22
9

2
0
0
0

27
9
7

5
4
5

60
100
100

73
83
13

1
2

7
4
3
0

50
64
~7

0
1
0
0

4
3
0

23
19

5
1
2

0
0
0

88
7

5
6
0
0

7
8
8
0

38
26

18
27
10
9

5
0
0
0

120

114

8
8
0

6
5
1

1
1

0
0

3
4
4

7
1

34
48
15
16

13
9

11
1

29
12
2

35
49
15
16

42
50

2
0
0

19
31

27
0

3
6
3

9
10
5
3

11
21
3

1
2
1

0
0
0
0

2
6
1
0

2
4
2

9
10
5
3

9
15
2
0

7
7
2

1
1

0
0

5
10
5
0

25
11
3

58
20
19

32
18
5

44
59
20
19

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM
774-711 O— '66 4

345

1 RIGHT BANK ABUTMENT

SPILLWAY

Figure 3. — Lower end of right ladder at different water
levels. Diagrammatic sketch shows photo areas: (a)
high flows; (b) intermediate flows; and (c) low flows.

The estimating equation
is given by

RJTa

where

Tb= Number of tagged
dam

for survival rate (k)

fish released below

Rb= Number of tagged fish recovered from

T,
Ta= Number of tagged fish released above

the dam
R„= Number of tagged fish recovered from

If the value of the ratio is one then mortality is
zero. Where the value of this ratio is less than
one, then the corresponding mortality rate is
given by \ — k.

The results of tagging experiments on the 3-
year-old sockeye are shown in table 6. It is
apparent that too few 3-year-old sockeye were
tagged above the dam to afford meaningful com-
parisons between above and below dam experi-
ments and to give estimates of mortality rates.
No mortalities were evident from the limited data
available. A comparison of the recovery propor-
tions of tagged fish released below the left and
right fishways shows right bank releases having a
higher recovery rate in 2 of the 3 years. For all
years combined the two recovery rates were nearly
identical.

346

U.S. FISH AND WILDLIFE SERVICE

■* k

*.?&£**

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

347

FinnRE 4. — Lowering tagged fish off the deck of the dam.

In table 7 are listed the estimates of mortalities
based on all 4-year-old sockeye recoveries.

Compared with the proportions of tagged fish
recovered from the area AL (left bank above the
dam) releases, tagged fish released on the left bank
below the dam suffered mortalities of about 10, 6,
and 16 percent in 1954, 1955, and 1956, respec-
tively. Tagged fish released on the right bank
below the dam suffered mortalities of about 22,
12, and 18 percent in the corresponding years.
We would conclude from these point estimates
that tagged fish released below the dam suffered
a mortality due to the dam, and that the mortality
rate was greater for fish released on the right bank
below the dam than for fish released on the left
Imnk below the dam.

Compared with the proportions of tagged fish
recovered from the AK (right bank above the
dam) releases, tagged fish released on the left bank

below the dam suffered no mortality due to the
dam in either 1955 or 1956. Neither did tagged
fish released on the right bank below the dam.
The point estimates for 1956, it should be recog-
nized, are based on a release of only 16 fish in area
AR.

In combining the data for the 3 years, we could
conclude, on the basis of recoveries from area AL
releases, that tagged fish released on the left bank
below the dam suffered a mortality of about 16
percent because of the dam, and that tagged fish
released on the right bank below the dam suffered
a mortality of about 21 percent because of the
dam. Little or no mortality was indicated on the
basis of releases in area AR (0 and 2 percent).

When comparing proportions of tagged fish
recovered from total releases below the dam with
all releases above the dam, we obtained point
estimates of mortalities due to the dam of about
15 percent in 1954, 4 percent in 1955, 15 percent
in 1956, and 15 percent for all years.

TAGS USED BELOW DAM

'AG COMPONENTS TAG COMBINATIONS

Disk

Disk on Disk on Spaghetti
Bar Spaghetti Streamer Bor ond sirearner

** — ■*

)

2
3

5 Inches

TAGS USED IN FOREBAY

Disk Patterns

®©e@®

Figure 5. — Kinds of tags used during the Rock Island
tagging experiments.

■MS

U.S. FISH AND WILDLIFE SERVICE

Table 4. — Estimates of total single recoveries in the Okanogan system by age group and release area, Rock Island Dam sockeye

lagging, 1954-56

Year and release area

Number

recovered

area 2

(A)

Number

recovered

area 3

Number

observed

area 2

(02)

Number

observed

area 3

(Os)

Ri+Ri+Oi+Oi

Number

recovered

second time

in area 3

(Kk)

§:(!>'+<»

Total
correction

Estimated

total single

recoveries

(S)

3-year-old sockeye

WSi

Below dam, left bank

Below dam, right bank
Above dam, left bank

1965

Below dam, left bank

Below dam, right bank

Above dam, left bank

Above dam, right bank

1956

Below dam, left bank

Below dam, right bank

Above dam, left bank

Above dam, right bank

5
5
0
0

3
4
5
0

6
5
1

1
1
0
0

4
4
0

50
64

0
1
0
0

4
4
3

1
2
1

0
0
0
0

2
6
1
0

89
95
9

7
0
0

1
0
0

0
0
0
0

2
0
0

(1
0
0
0

0
0
0
0

0
0
0

0
0
0
0

0
0

0
0
0
0

86
95

6
7
0
0

12
18
13
0

4-year-old sockeye

196i

Below dam, left bank

Below dam, right bank

Above dam, left bank.

1966

Below dam, left bank

Below dam, right bank

Above dam, left bank

Above dam, right bank

1966

Below dam, left bank

Below dam, right bank

Above dam, left bank

Above dam, right bank

15
7
0

22
9

2
0
0
0

23
7
1

34
48
15
16

13
9

11
1

23
19
6

1
5
1
2

3
0
0
0

4
2

9
10
5
3

9
15
2
0

63
37
9

61
85
30
28

3
0
0

2
1
0

1
1

0
0
0

5
0
0

0
0
0
0

2
0
0
0

1
0
0

1
0
0
0

2
0
0
0

9
0
0

1
0

5
0
0
0

58
84
30
27

22
24
13

We observe from the estimated confidence limits
that the lower limits bracket zero in most instances
and range to about 5 percent. The upper limits
range from 20 to about 46 percent.

Another procedure was to estimate mortality
rates based on recoveries of 4-year-old sockeye at
Tumwater Dam (table 8). Compared with the
proportions of tagged fish recovered from area
AL (left bank above the dam) releases, tagged fish
from left bank-below releases suffered mortalities
of about 21, 0, and 26 percent, respectively, for
1954, 1955, and 1956. Tagged fish released on
the right bank below the dam suffered mortalities
of about 42, 23, and 29 percent, respectively, for
the same 3 years.

Compared with the proportions of tagged fish
recovered from the area AR releases (right bank
above the dam), the tagged fish released at the
right and left banks below the dam suffered no
mortalities.

Combining the data for the 3 years, we observe
on the basis of area AL releases that tagged fish
released below the left fishway suffered a mortality

of about 22 percent and that tagged fish released
below the right bank fishway suffered a mortality
of about 39 percent. No mortality was indicated
on the basis of releases in area AR ; however, com-
paratively few fish were released there.

Point estimates of mortality rates, obtained
from comparisons of proportions of tagged fish
recovered from total releases below the dam with
all releases above the dam are about 29 percent in
1954, 0 percent in 1955, 25 percent in 1956, and
21 percent for all years.

Considering the confidence limits of these
mortality rates based on Tumwater Dam re-
coveries, we observe the lower limits to bracket
zero in two instances and range to 28 percent. The
upper limits range from about 32 to 66 percent.

It is readily apparent that the analyses of the
sockeye tagging data gave conflicting results of
mortalities caused by the dam. On the one hand,
many experiments indicated substantial mortal-
ities, and mortalities apparently were greater for
fish released below the right bank fishway. On

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

349

Table 5. — Summary of Rock Island Dam sockeye tagging data by age group, 1954-56

Total
number

released

3-year-old sockeye

4-year-old sockeye

Year and release area

Number

released

Estimated

number

recovered in

Okanogan

Number
released

Number recovered

Estimated

total
Okanogan

Tumwater

Estimated
in Okanogan

Other

areas

recoveries

19Si

802
670

244
290

86
95

558
380

109
54

54
37

140

He low dam, right bank

132

Total

1,472

534

181

938

163

272

Above dam, left bank .. .. ......

157

118

Total .

157

118

1955

579
597

32
53

6
7

547
544

130

58
84

8
8

Total

1,176

1,091

221

142

155

210
143

199
137

43
17

Total..

353

336

1966

393

358

109
107

12
18

284

251

79
67

22
24

Total

751

216

535

146

402
19

132
3

13
0

270
16

101
3

7
0

Total .

421

135

286

104

Totals 1951,-66-69

1,774
1,625

385

450

104
120

1,389
1,175

318
212

134
145

21
19

238

265

Total..

3,39!)

K3.r.

224

2,564

530

279

503

769
162

IS.'

587
153

173

52
28

Total .

931

191

740

193

102

the other hand, many of the experiments indicated
no mortalities caused by the dam.

Returns from below the dam by date oj tagging. —
The upstream recoveries of tagged sockeye,
released below the dam, indicated a fairly uniform
pattern of returns for all experiments (figs. 6,7,
and 8). As tagging experiments were alternated
between left and right hanks on alternate days,
these graphs show a fairly consistent pattern of
returns for both release areas and for the duration
of the tagging season. The percent-recovered
curve in 1954 assumed the shape of the numbers-
tagged curve, with fewer returns from the tails of
the experiments. Percentage returns for 1955
and 1956 show a remarkably uniform pattern.
The large numbers tagged, shown for July 26
and 28 in 1955 and for July 24 in 1956, arc the
result of combining left and righi hank experi-
ments, as experiments were conducted on both
hanks on those dates. Returns of nearly 50

percent from the August 3, 1955, experiment
(fig. 7) are a result of observing a large number
of that day's tagged fish passing Tumwater Dam,
more fish observed than for any other single ex-
periment. It might be that this particular sample
contained relatively more Wenatchee fish than the
other samples.

Returns from below dam compared with water
How.— In order to determine the. influence of
different water levels on fish passage at Rock
Island Dam, tag recoveries from releases at each
bank below the dam were compared with water
(low (figs. 9, 10, and 11). In general, the tag
returns from both hanks showed a fairly consis-
tent pattern despite large changes in flow during
the experiments.

The returns for 1954 merit attention, since fewer
returns are indicated for experiments on August
L0-13 during the low river Hows (fig. 9). These

350

U.S. FISH AND WILDLIFE SERVICE

Table 6. — Estimated

mortality rates due to I

took Island Dam based

on 3-year-old sorkeye tag recoveries

Number
released

Estimate
number
recovered

Proportion

recovered

Estimate of mortality rates

Year and release area

Til

." tbl
tar

. tbr
tal

. Tbr
tar

tbl+tbr
tal+tar

1954

244
290

86
95

0.352
.328

-0. 524

-0. 420

Total

634

181

.339

—0 468

.231

Total

.231

1955

32
53

.188
.132

Total

.153

0
0

Total

1956

109
107

12
18

.110
.168

-.122

-.714

Total

216

.139

—.448

132
3

.098
0

Total

135

.096

Totals 1951,-56-56

385
450

104
120

.270
.267

-1.231

-1.207

Total

835

224

.268

-1.330

182
9

122
0

.121
0

Total

191

.115

fewer returns undoubtedly are related to a di-
minished effort to recover tags from these experi-
ments. Fish counting and tag observing were dis-
continued at Zosel Dam from August 20 to August
26, at a time when tagged fish were still passing
and when the number of tags from the August
10-13 experiments should have peaked there.
Therefore, with comparable recovery effort, tag
returns from these experiments probably would
have been greater than indicated. It is noted
that the 1955 returns from this same time period,
August 9-11, and for comparable water flows
(fig. 10), were consistent with returns from earlier
experiments occurring at high flows. It is evi-
dent, as shown by upstream tag returns, that
changes in flows at Rock Island Dam had little
effect on the ability of sockeye to pass the dam.

Chinook

In order to compare recovery ratios of chinook
salmon tagged above and below the dam, it was

necessary to separate the chinooks by race.
Races at Rock Island Dam were reported by
Fish and Hanavan (1948) as spring and summer
chinook. Spring chinook, passing Rock Island
Dam earlier in the season than summer chinook,
migrated to smaller, more remote spawning
streams. In these streams, tagged fish were
much easier to observe and recover than in larger
streams, such as the Wenatchee and lower Methow
Rivers (the summer chinook spawning areas).
Thus, recoveries from spring chinook tagging
experiments were much greater than from experi-
ments on summer chinook.

Upstream tag recoveries for all chinook experi-
ments are given in table 9. Many samples were
too small to compare returns statistically. Only
in 1956 were sufficient fish obtained to release at
the two banks below the dam and above the dam.
Returns of spring chinooks tagged below the dam
were virtually the same (27 percent) for the 3

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

351

Table 7. — Estimated mortality rates due to Rock Island Dam based on total 4-year-old sockeye recoveries

[95 percent confidence limits]

Number
released

Estimate
number
recovered

Proportion

recovered

Estimates ot mortality rates

Year and release area

1 TBL

Tal

1 TBL

Tar

. tbr
tal

. Tbr
Tar

1 tbl+tbr
tal-\-tar

1954

558
380

170
101

0.305
.266

0.100 (-0.159
to 0.359).

0.215 (-0.028
to 0.458).

938

271

.289

0.147 (-0.089

to 0.383).

118

.339

118

.339

1955

547
544

196
183

.358
336

0.064 (-0.136
to 0.264).

-0.065

0.120 (-0.071
to 0.311).

1,091

379

.347

0.044 (-0.116

to 0.204).

199
137

.382
.336

336

122

.363

1956

284
251

107
92

.377
.366

0.158 (-0.014
to 0.330).

-.508

0.183 (0.008 to
0.358).

-0.464

535

199

.372

0.149 (Oto

0.298).

270
16

121
4

.448
.250

Total

286

125

.437

Totals 195i-5S-56

1,389
1,175

473
376

.340
.320

0.1 =W (0.053 to
0.263).

-.040

0.208 (0.103 to
0.313).

0.022 (-0.221
to 0.265).

2,564

849

.331

0.147 (0.054 to

0.240).

587
153

237

.404
.327

740

287

.388

years. In 1956, returns from tagging at the right
bank were considerably lower than those from the
left bank; however, the reverse was true for 1955.
No reasonable explanation can be offered for these
differences. Perhaps conditions which may have
caused low recoveries from the right bank one
season were not present the other season, or it
may have been chance that upstream recoveries
varied as they did in the 2 years.

The data for 1956 indicated a loss of fish re-
leased below the right hank fishway when recovery
proportions were compared to recovery propor-
tions of fish released above the dam (19.5 percent
compared to 24.4 percent). In terms of mortality

rates, in the same manner as was done for the
sockeye, this would indicate a 20 percent mortality
for fish tagged below the right bank. No mortali-
ties were indicated when comparing total returns
from below the dam with returns from above the
dam.

While summer chinook tag returns are com-
paratively few, the recovery ratios are consistent
over the years and for the different areas of release.
Only in 1954 was there an indication of mortalities
for right bank tag releases (7.1 percent recovered
compared with 7.8 percent recovered from above
the dam). In the other 2 years there was no
indication of mortalities. There was no indication

352

U.S. FISH AND WILDLIFE SERVICE

Table 8. — Estimated mortality rates due to Hock Island Darn based on Wenatchee sockeye recoveries

[95 Percent confidence limits]

Number
released

Estimate
number
recovered

Proportion
recovered

Estimates of mortality rates and confidence limits

Year and release area

TBL

tal

. TBL

Tar

. TBR

tal

, trr
Tar

. TBL+TBR
TAL+TaR

1954

558
380

109
54

0.195
. 142

0.207 (0.08 to
0.497).

0.423 (0.186 to
0.660).

938

163

.174

0.293 (0.044 to

0.542).

118

.246

Total —

118

.246

1955

547
544

130
91

.238

.167

-0.102 _..

-0.919

0.227 (-0.030
to 0.484).

-0. 347

1,091

221

.203

-0.134.

199

137

.216,
.124,

336

.179

1956

284
251

79
67

.278
.267

0.257 (0.072 to
0.442).

-.479

0.286 (0.099 to
0.473).

-.420

535

270
16

146

101
3

.273

0.250 (0.089 to

0.411).

.374
.188

Total

286

104

.364

Total, 1951,-55-56

1,389

1,175

318
212

.229
.180

0.224 (0.099 to
0.349).

-.748

0.390 (0.280 to
0.500).

-.374

2,564

530

.207

0.207 (0.092 to

0.322).

587
153

173

295

. 131

Total

740

193

.261

Table 9. — Upstream returns of tagged spring and summer
chinook by area of released at Rock Island Dam, 1954-56

Year and release area

Spring chinook

Summer chinook

Tagged

Recovered

Tagged

Recovered

195i
Below dam, right bank.

Number
150

Number
40

Percent
26.7

Number
113

Number
8
7

Percent
7.1

8.8

Total below dam.

150

26.7

193
217

15
17

7.8
7.8

1955
Below dam, right bank.
Below dam, left bank...

122
70

38
13

31.1
18.6

66
34

10
2

15.2
5.9

Total below dam.
Above dam ... ..

192
3

51
1

26.6
33.3

100
99

12
9

12.0
9.1

1956

Off dam, right side

Off dam, left side

159
154

31
53

19.5
34.4

92
113

11
11

12.0
9.7

Total off dam

313

168

84
41

26.8
24.4

205
199

10.7
10.6

of mortalities when comparing total returns from
above and below the dam.

In view of these similar recoveries of tagged
chinook salmon released above and below Rock
Island Dam, we cannot conclude that there is a
substantial mortality caused by the dam. For
spring chinooks, there are indications of a loss of
fish released below the right bank ladder in 1956.
Data are not available for determining if this loss
exists for the other 2 years.

RETURNS AT ROCK ISLAND
Identity of Tags and Species

The correct identity of tag returns at Rock
Island Dam depended upon the fish counters'

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

353

DATE OF TAGGING

by the counters (table 10). Many chinooks
(obviously jacks) were called sockeye. Jacks are
precocious male chinooks, and are similar in size
to sockeye. The error in mistaking sockeye for
chinooks was relatively small. No tagged steel-
head were reported by the counters at Rock Island
Dam; one tagged steelhead, however, was observed
upstream at Tumwater Dam. Similar errors were
made in 1955 and 1956, although the fish counters
were asked to keep the counting boards at the
minimum depth consistent with efficient fish
passage. The magnitude of error was not deter-
mined for these years.

2. The disproportionate returns of the different
types of tags used gave evidence of errors in tag
identity at Rock Island Dam. A far greater
percentage of bar tags was observed at Rock Is-
land in 1954 and 1955 than of spaghetti tags (table
11). Upstream, however, the percentage re-
turns of the two tags were approximately the same
for both years. The streamer tag was substituted

Figure 6. — Numbers of sockeye tagged below Rock
Island Dam, and recoveries of tagged fish upstream,
expressed as percentages of the number tagged each day,
1954.

identifying accurately the various tags and species
of fish as the fish crossed counting boards. The
tags were more difficult to identify at Rock Island
than at upstream points because of the need for
counting large numbers of fish while simultane-
ously identifying tags, and because of the speed the
fish moved across the counting boards. The
misidentification of both tags and species was a
source of error in the Rock Island tag return data
as exemplified in the following illustrations:

1. In some of the 1954 experiments, fish counters
recorded as tagged species which had not been
tagged. In other experiments, they recorded
greater numbers of tag observations of species than
fish tagged, and on several occasions they counted
fewer jack chinook in the traps than were tallied
during subsequent tagging. We revised our
tagging procedure for some experiments in 1954
to determine the magnitude of error in species
identification. Instead of tagging all species with
one color combination as was usually done, we
tagged the various species with different color
combinations and noted the returns as identified

10 20 30
JULY

DATE OF TAGGING

FuiURE 7. — Numbers of sockeye tagged below Rock
Island Dam, and recoveries of tagged fish upstream,
expressed as percentages of the number tagged each
day, 1955.

354

U.S. FISH AND WILDLIFE SERVICE

for the spaghetti tag in 1956, and, as observed,
returns were similar at Rock Island Dam and
upstream for the two tags. It is evident, there-
fore, that the counters at Rock Island Dam did

Table 10.-

- Errors in species identification at Rock Island
Dam in 1954

Species and date tagged

Tagged

Species reported
by counters

Error

Chinook:

Number
6

Number
0.. -.

Percent

("20 Chinook

\2 steelhead.-

f 13 chinook __ - .
\2 steelhead

\ 66.7
\ 69.2
} 83.4

6 - -

Total

(50 Chinook

Usteelhead

flO chinook

} 70.5

Sockeye:

Aug. 5

6..

139

/ 136 sockeye

\l chinook

90 sockeye

171 sockeye 2

} 0.7
0

125

} 10.1
} 8.3

122 sockeye

Total .

370

1319 sockeye

\ll chinook .__

} 3.3

1 The color and tag combination used here was also used 15 days previous.
Some returns may have been attributed to the previous experiment.

2 The total of 79 fish observed is an obvious error in tag identity.

~! 1 I

10 2 0

JULY

DATE OF TAGGING

Figure 8. — Numbers of sockeye tagged below Rock Island
Dam, and recoveries of tagged fish upstream, expressed
as percentages of the number tagged each day, 1956.

~ 450

u.400

O350
o

in
^300

§2 50
<

O200

S 150

LL.

100

LEFT BANK

RIGHT BANK

10 20 30 10 20 30

JULY AUGUST

DATE OF TAGGING

Figure 9. — Recoveries of tagged sockeye upstream ex-
pressed as percentages of the number tagged at each
bank below, compared with water flow, 1954.

not discriminate between the tags in 1954 and
1955.

These errors in species and tag identification
thus affected the reliability of the tag return data
at Rock Island Dam, and the data must be used
with caution.

Sockeye and Chinook

The results of the fish counters' observations of
tagged fish (including the few steelhead tagged)
crossing the counting boards for the four seasons
of tagging are shown in table 12. Although the
salmon were released below the dam at various
places on both sides of the river, most of the tags
were observed at the left ladder. Comparatively
few were recorded at the right ladder, even though
roughly half of the salmon were released a short
distance away. The counters observed 85 percent

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

355

of the tags at the left and center ladders for the 4
years. While only 64 to 86 percent of the fish
released below the dam were observed at the count-
ing boards, we cannot say with certainty that these
missing tags indicated mortalities caused by the
dam.

These are some possible reasons for the apparent
tag losses :

1. Counters did not identify tagged fish crossing
the counting boards.

2. Tagging harmed the fish.

3. Fish lost the tags.

4. Tagged fish refused to re-pass the dam.

5. The dam itself caused mortalities.

The counters did overlook tagged salmon. On
a few occasions when the forebay trap was fished,
we captured tagged fish the counters had not
reported. In some experiments, we recovered
more tags upstream than the counters reported at

3 200

DATE OF TAGGING

Figure 10. — Recoveries of tagged sockeye upstream ex-
pressed as percentages of the number tagged at each
bank below, compared with water flow, 1955.

Table 11. — Returns at Rock Island Dam and upstream of
- different kinds of lags used

Tagged

Returns at
Rock Island

Tagged!

Returns
upstream

Observed '

Recovered

1951,
Bar ...

Number

1,284

565

1,174
310

7711
509

Number
1,121
241

855
123

671
423

Percent
87.3
42.7

72.8
39.7

87.1
83.1

Number

1,260

556

1,000
179

764
506

Number
320
155

317
50

197
128

Percent
25.4

27.9

1955'
Bur

31.7

27.9

1956
Bur

25.8

25.3

1 Undetermined tap observations at Rock Island not identified as bar,
spaghetti, or streamer are omitted.

• Steelhead and those tapped fish removed at Rock Island for other experi-
ments were omitted (ruin this column.

3 Only soekcyc are included in the upstream returns in 1955 because of the
unequal recovery effort spent on chlnooks tapped with the two kinds of taps.

40r
o 30

£ 20

uj I O

£ o

K 40
uj

30
20
10

LEFT BANK

RIGHT BANK

10 20 30 10 20

JULY AUGUST

DATE OF TAGGING

Figure 11. — Recoveries of tagged sockeye upstream ex-
pressed as percentages of the number tagged at each
bank below, compared with water flow, 1956.

:•;;,(,

U.S. FISH AND WILDLIFE SERVICE

Table 12. — Returns of tagged fish at Rock Island Dam by
ladder, 1953-56

Tagged

Observations bv ladder

Year

below
Rock

Total tag

observations

Island '

Left

Center

Right

Nzim-

Num-

Per-

Num-

Per-

Num-

Per-

Num-

Per-

ber

cent

ber

cent

ber-

cent

ber

cent

1953 -

764

298

39.0

11.4

106

13.9

491

64.3

1954

1,849

788

42.6

399

21.6

188

10.2

1,375

74.4

1955

1,484

656

44.2

205

13.8

127

8.6

988

66.6

1956.

1,279

724

66.6

214

16.7

156

12.2

1,094

85.5

Total.

5,376

2,466

45.9

905

16.8

577

10.7

3,948

73.4

1 Tagged members included Chinook, sockeye, and steelhead.

Rock Island Dam. An illustration was the Bonneville
experiment (app. p. 366) where a distinctive copper
and black disk tag was used ; only 6 of these tags
were reported at Rock Island, but 14 were re-
covered upstream. In view of these examples,
it was undoubtedly true that the counters missed
tagged fish.

Tagging operations have caused mortalities.
Schaefer (1951) concluded that there was a serious
differential mortality among the tagged and un-
tagged fish during the long migration between the
Harrison trap and the Birkenhead River. Nelson '
found a differential mortality between tagged and
untagged sockeye migrating between Karluk
River weir and weirs on the tributary spawning
streams of Karluk Lake.

The loss of tags from tagged fish apparently was
not a reason for the missing tags at Rock Island
Dam. No tag-scarred salmon were reported by
the counters at Rock Island Dam, and neither
were any caught in the traps, though many
tagged fish were captured there.

Tagged salmon may have refused to reenter the
fishways after tagging. In 1956, five tagged
salmon were observed in the Oregon Fish Com-
mission's trap at McNary Dam, located approxi-
mately 160 river-miles downstream from Rock
Island Dam. Also, a tagged sockeye was observed
at the Redfish Lake weir in Idaho, about 700
river-miles from Rock Island Dam. Howard
(1948) reported that handling during tagging
operations at Cultus Lake, British Columbia,
apparently caused some of the tagged sockeye to
remain in the area immediately above the tagging

location, rather than continue their migration.
Undoubtedly some of the missing tags at Rock
Island Dam could be attributed to straying.

Finally, mortalities could be caused by the dam.
Mortalities were indicated for some experiments
but not for others when comparing upstream
recovery ratios from tagged fish released above and
below the dam.

Returns by area oj release. — The results of tag
returns by ladder are shown in table 13. These
data show a consistent pattern of passage over the
ladders for the 3 years and for the two release
areas. Only 6 to 12 percent of the fish used the
right ladder.

The observed differences in returns from the two
banks over the 3 years would indicate that right
bank tag releases were not as successful in passing
the dam as left bank releases.

Table 13.-

-Tag returns by area of release and ladder,
1954-56

Tagged

Observations by ladder '

release area

Left

Center

Right

AU ladders

1954
Right bank.
Left bank..

Num-
ber
950
899

Num-
ber
389
352

Per-
cent
40.9
39.2

Num-
ber
192
187

Per-
cent
20.2
20.8

Num-
ber
80
92

Per-
cent
8.4
10.2

Num-
ber
661
631

Per-
cent
69.6
70.2

1955
Right bank.
Left bank..

793
691

311
302

39.2
43.7

91
104

11.5
15.1

47
70

6.9
10.1

449
476

56.6
68.9

1956
Right bank.
Left bank..

616
663

331

385

53.7
58.1

94
119

15.3
17.9

12.3
11.6

501
581

81.3
87.6

i Nelson, Philip R., unpublished data 1947 and 1948. U.S. Fish and Wild-
life Service, Seattle, Wash.

i Unidentifiable tags were excluded.

Since almost all of the fish were trapped in the
left ladder or in the forebay trap at the head of
this ladder, and since they were released at both
banks below the dam, it was important to know
whether these fish had learned the route for their
second passage of the dam. Accordingly, the tag
returns were listed by trapping site and by area
of release (table 14). Regardless of where the fish
were trapped or released, they returned in approxi-
mately the same ratio over the three ladders with
the least returns always at the right ladder. It is
evident that the salmon did not learn a route and
then repeat this route for a second passage over
the dam. Neither were they necessarily
frightened away from a ladder, since the majority
of fish returned to the left ladder, where most were
trapped previously.

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

357

Table 14. — Tag returns by ladder of salmon trapped at both ladders and released at both banks below Rock Island Dam, 1954-55

Year and trapping area

Area released

Tagged

Observations by ladder '

Center

Right

196i

Right ladder...

Left ladder

1966

Right ladder

Left ladder

Right bank
Right bank
Left bank . .

Right bank
Right bank
Left banlc..

Number
178
748
923

363
430
691

Number

331

354

169
142
302

Percent
64.4
57.9
55.9

72.5
65.7
63.4

Number
20
172
187

49
42
104

Percent
23.0
30.1
29.5

21.0
19.4
21.8

Number
11
69
92

Percent
12.6
12.1
14.5

6.4
14.8
14.7

1 The percentage by ladder is based on total observations.

Tagged and untagged fish movements. — Table 15
shows the comparison of choice of ladders between
tagged and untagged salmon lor each season of
tagging. Chinooks and sockeye were combined
because of the error of confusing chinooks (jacks)
with the sockeye. The percentage returns at the
right ladder agreed closely with those of the un-
tagged run. A somewhat larger proportion of the
untagged run, compared with the tagged fish,
chose the left ladder for passage. The percentage
returns at the middle ladder were greater than the
proportion of untagged fish at this ladder. This
may be because right bank releases, failing to enter
the right ladder, were attracted by the center lad-
der before the left ladder. Generally speaking,
however, the tagged and untagged salmon were
similar in their patterns of passage.

During the years of the tagging experiments,
the four spillway regulating gates nearest the
right ladder were kept closed so the high-velocity
flows would not interfere with fish approaching
along the right bank. In 1957, in order to test
their influence on fish passage, these gates (one

Table 15. — Combined chinook and sockeye counts of the
tag returns and the untagged runs by ladder, 1954-56

Year

Combined Chinook and sockeye counts

Total

Left ladder

Center ladder

Right ladder

1964

Tagged

Untagged

1956

Tagged

Untagged

1956

Tagged

Untagged

Number

787
86. 439

654

139, 555

724
88,154

Per cent
57.3
70.0

66.3

77.4

66.2
75.0

Number
399
17, 144

205
22. 415

214
18, 697

Percent
29.0
13.9

20.8
12.4

19.6
15.9

Number

188

19, 892

127
18, 448

156

10, 677

Percent
13.7
16.1

12.9
10.2

14.2
9.1

Number

1.374

123 475

985
180. 41S

1,094
117.528

Total 1954-
1956.
Tagged

Untagged..

2. 165
314,148

62.7
74.5

818

58, 256

23.7
13.8

471
49.017

13.6
11.6

3,454
421,421

or more) were opened when most of the fish passed
the dam. The percentage of chinooks and sockeye
using this ladder in 1957 increased to 24 percent,
compared to an average of 15 percent for 1953-56.
This was the pattern of fish passage at the right
ladder by species — chinooks, 19.8 percent; sockeye,
26.8 percent; and steelhead, 16.6 percent. No
tagging was done in 1957, and a comparison of
tagged fish movements could not be made.
Apparently the salmons' choice of ladders can be
influenced by manipulating the regulating gates
and by the resulting changes in flow patterns
below the dam.

DETERMINATION OF DELAY AT
ROCK ISLAND

In this paper delay means the period of time
that Rock Island Dam checks the migration of
salmon under present conditions.2 Delay may
cause salmon mortalities prior to spawning. Some
causes of delay may be flood waters in rivers, low
flows, high water temperatures, areas of difficult
passage (as in precipitous canyons), or dams in
rivers. Delay here is measured as days elapsing
between release of tagged fish and subsequent
observations at the counting boards. The delay
also is assessed by comparing, at upstream points,
the time of arrival of tagged fish released above
and below the dam. The difference in time of
arrival at an upriver point would be a measure of
delay at the dam, and this difference should
correspond to the delay observed at Rock Island
Dam. It will be shown that this was true.

2 An argument advanced is that studies of delays at dams sriould consider
comparisons of travel rates before and after a dam is built. This has seldom
been accomplished; subsequent to this study, comparisons of travel rates
were made before and after Rocky Reach dam was built. Major, Richard
L. and James L. Mighell. A study to measure delay to upstream migrating
salmonids at Rocky Reach Dam. Manuscript. Bureau of Commercial
Fisheries Biological Laboratory, Seattle, Wash.

358

U.S. FISH AND WILDLIFE SERVICE

RETURNS FROM UPSTREAM
Sockeye Salmon

It was necessary that days-out of tagged fish at
upstream points be measured at a point where a
minimum of mixing of (1) chronological order of
movement and (2) delay might occur. Zosel Dam,
on the Okanogan River, approximately 145 river
miles above Rock Island Dam, appeared the best
place for measuring the period of migration of
tagged sockeye salmon. The sockeye passing
this dam were headed for Lake Osoyoos and the
spawning areas above the lake. They passed the
dam easily, either through fishways or through the
spillway. Unfortunately, not many tagged fish
were released in the forebay at Rock Island in

1954, the year many sockeye and tags were
observed at Zosel Dam. In 1955 and 1956, larger
samples were released above the dam at Rock
Island but most fish passed Zosel Dam unobserved.
These data, at Zosel Dam, however, did allow us
to compare the migration period of different lots
of tagged fish.

Tumwater Dam on the Wenatchee River, the
only other fish-passage observation point, pre-
sented a delay and mixing problem which pre-
cluded a reliable comparison of time periods for
different tagged lots. At this dam, all fish had to
find and ascend the ladder to pass the dam, and
this offered chances for mixing and delaying of
various parts of the salmon runs. The data ob-
tained at Tumwater Dam are given for comparative
purposes.

Figure 12 shows the days-out period at Zosel
Dam for sockeye released at three areas at Rock
Island. Looking at the modal values, we note a
2-day difference between forebay and left bank
below the dam releases for both 1954 and 1955.
The right bank modes, however, show a 3-day
difference for 1954 and a 4-day difference for

1955. This would indicate right bank releases
were delayed longer than left bank releases. The
mean values do not indicate this difference be-
tween banks. Since the means are influenced by
extreme values, however, the modal values should
be preferred when making comparisons, provided
the data are sufficient for forming smooth distri-
bution curves. The number of observations leave
something to be desired, but they indicate a delay
of from 2 to 4 days at Rock Island, and a greater
delay for right bank releases than left bank
releases below the dam.

Figure 12. — Number of days out at Zosel Dam of tagged
sockeye released at three different areas at Rock
Island, 1954-55.

At Tumwater Dam, the difference in days-out
between above- and below-dam experiments aver-
aged 2 to 3 days in 1954 and 1955 (table 16). We
observed that for these 2 years right bank releases
took longer to pass than left bank releases. The
1956 results may have been affected by changed
flow patterns at Tumwater Dam, the entire river
was spilled over the dam and no water was di-
verted for power production as in previous seasons.
The great range in individual days-out of tagged
sockeye is indicated by the large standard devia-
tions shown for the data.

Chinook

Our only upstream measure of the days-out
period of tagged chinook salmon was obtained
at Tumwater Dam. All other tag recoveries
were from the spawning grounds or hatcheries,

Table 16. — Means and standard deviations of days-out at
Tumwater Dam of tagged sockeye released at different areas
at Rock Island Dam, 1954-56.

[Figures in parentheses are standard deviations]

Release area at Rock Island Dam

Difference
between

Year

Left hank
below

Riebt bank
below

Total
below

Above
dam

above and
total below

1954

23.5
(7.3)
21.6
(7.5)
21.5
(8.0)

24.7
(7.0)
22.1
(7.1)
21.5
(9.4)

23.9

(7.2)
21.8
(7.3)
21.5
0.4)

20.8
(5.9)
19.9
(8.2)
20.3
(7.9)

3.1

1955

1.9

1956

1.2

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

359

where the chronological order of the arrival of
tagged fish could not be determined. At Turn-
water Dam, moreover, migrating chinooks were
subject to delay, and conclusive data of the
time-out period for fish from the different tagging
areas were not obtained. The days-out at
Tumwater Dam for individual chinooks ranged
from 11 to 65 days, and there was no evidence
that any one group of releases was different from
another group.

RETURNS AT ROCK ISLAND

Sockeye

As hypothesized previously, the difference
in days-out at upstream points between above-
and below-dam releases should equal the days-out
period at Rock Island Dam of below-dam releases.
The results at Rock Island Dam (fig. 13) confirm
the hypothesis. The majority of fish passed
through the fishways within 2 to 4 days after
being released below the dam. In 1953, the peak
of the days-out curve occurred a day earlier
than in 1954-56. This may have been because
the majority of fish in 1953 were tagged during
a 3-day period near the end of the run in contrast
to the season-long tagging of the later years.

The comparisons of days-out by area of release
at Rock Island are shown in figures 14, 15, and 16.
At first glance we have a fairly consistent picture
of passage from the two areas of release, with the
exception of the right bank releases in 1956. A
better comparison of the days-out period for
each release area is gained from the following

1 1
■ i

1953

1954

1955

\
\

1956

i
It
h

- " "../■

r^.i'V?-. V.

■»'''>,V''.-V"r<'TV'ru^ *■»— , — , — , — , — , — ,

RIGHT BANK BELOW

- Left ladder
Center lodder
Right ladder

I n. ire 13. — Comparison of days-out at Rock Island of
tagged sockeye released below the dam, 1953-56.

I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 IG 17 18 19 20 21 22 23 24 25 26
DAYS-OUT

Figure 14. — Days-out of tagged sockeye at Rock Island
for each area of release expressed in percentages of
total observations by ladder, 1954.

array of modal values of days-out for each tag
release area and the ladder of passage (table 17).

In 1954, right bank releases took a day longer
to pass at each ladder than the left bank tag
releases. This difference was not noted for
other years except in 1955, in the center ladder.
In 1956, right bank releases passed sooner than
left bank releases. The 1956 tagged fish, it is
recalled, were released off the face of the dam close
to the fishways. Apparently the few sockeye
using the right ladder moved into the ladder
immediately after tagging and the remainder
moved downstream or across the river. Those
sockeye using the right ladder possibly moved up
sooner upon finding the ladder because of the
absence of resting areas below the ladder.

Measuring the number of days-out for tagged
salmon at Rock Island Dam depended on the
ability of the counters to distinguish the kinds
and colors of tags used. As previously pointed
out, the counters made many errors. To test if
the counters were approximately correct in identi-

360

U.S. FISH AND WILDLIFE SERVICE

fying most tags upon which the days-out data were
derived, the occurrence of tagged salmon, regard-
less of tag color or kind, was plotted by date and
compared with the total number of salmon tagged
(fig. 17). An examination of the graphs reveals

Table 17. — Modal values in days out for each tag release
area and ladder of passage

(Data from tips. 14, 15, and 10)

Releases

196i

1966

Ladder

Right

4-5

that the peaks and troughs of the tag occurrence
curve occur 2 to 4 days after the start and finish of
a tagging period. This 2- to 4-day lag compares
with the days-out curve of figure 13 and indicates
the counters were approximately correct in identi-
fying most of the tags from which the days-out
data were derived.

Undoubtedly the difference in time required for
salmon released above and below Rock Island
Dam to reach an upstream point reflects the
amount of time required for the below-dam releases
to pass the dam. Thus, it is reasonable to con-
clude that tagged sockeye were delayed 2 to 4
days below Rock Island Dam. Assuming that
tagged and untagged salmon migrate at similar
rates, Rock Island Dam delays sockeye approxi-
mately 2 to 4 days.
Chinook

At Rock Island Dam spring chinook peaked
after 1 day-out and summer chinook on the third

RIGHT BANK BELOW

- Left ladder
Center ladder
Right ladder

LEFT BANK BELOW

Lett ladder

1 v

Right ladder

i'p
i 1

•s\

V
J '
1 i

^Ai

RIGHT BANK BELOW
— Left ladder

Center ladder
-- Right ladder

I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 2021 222324 25
DAYS— OUT

9 10 II 12 13 14 15 16 17 18 19 2021 22 23
DAYS-OUT

Figure 15. — Days-out of tagged sockeye at Rock Island
for each area of release, expressed^ in percentages of
total observations by ladder, 1955.

Figure 16. — Days-out of tagged sockeye at Rock Island
for each area of release, expressed in percentages of total
observations by ladder, 1956.

I.OSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM
7T4-711 O— 66 5

361

I6C
140

I6C

1954 SEASON

Number Tagged - 1849

100

i Number Observed - 1375

' i Tagged
OBierved

(

2 0
0

' . . n n4l

_•

1955 SEASON
Number Togged - 1484
Number Observed - 987

rTUKIflJk t^JW

20 30 10 i

JUNE JULY AUGUST

DATE OF TAGGING AND TAG OBSERVATIONS

SPRINGS
■ Left bank
Right bonk

:S'-.W,\

SUMMERS

Left bank
R.gtil bonk

I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 2021 22 23 2425
DAYS - OUT

Figure 17. — Numbers of salmon tagged below Rock Is-
land, and numbers of daily tag observations at the
counting stations.

Figure IS. — Comparison of days-out at Rock Island of
tagged spring and summer run chinook, by area of re-
lease, 1956 season.

day after tagging (fig. 18). The drawn-out time
period noted for many summer chinooks may have
resulted from errors in species identification as this
run coincides with sockeye, or it may be charac-
teristic of the summer chinook to take longer to
pass the dam.

DISCUSSION
EXPERIMENTAL SITUATION

In view of conflicting results for different years
and for different tagging areas, it is pertinent to
review briefly the experimental situation and
sources of error of the tagging experiments.

We have assumed that the likelihood of recover-
ing or observing a tagged fish in a given recovery
area was the same regardless of the area of release
or time of tagging. This seems a reasonable as-
sumption, because recovery efforts on spawning
grounds were directed to all parts of the spawning
areas and throughout the period of spawning.
Tugged fish also were recorded as they passed
Zosel Dam on the way to the spawning grounds,
although sockeye could pass Zosel Dam without

362

passing through counting traps. At Tumwater
Dam, all fish, in order to pass the dam, had to pass
through a trap where tagged fish were easily ob-
served and counted.

We have assumed also that proportions of
tagged fish migrating to different spawning areas
were the same for the different release lots. In
sampling fish for tagging, salmon were trapped
throughout the duration of the run and usually
during the height of the daily migration. In many
instances, individual truck loads of fish were
divided between above-dam and below-dam lag-
gings. Other times, successive loads of fish were
divided between left and right bank releases and
above and below-dam releases. On this basis we
feel that the above assumption is reasonable.

Another factor relating to experimental control
was the kind of tag used for the various experi-
ments. All the fish released above the dam were
tagged with paired plastic disks. Different color |
combinations or single colors were used for dif-
ferent release groups. Tags used on fish released
below the dam consisted of disks of single colors

U.S. FISH AND WILDLIFE SERVICE

in combination with plastic bars, nylon streamers,
or vinyl tubing (spaghetti). Tags used below the
dam were larger than the tags used above the
dam. It might be argued that a larger, different
shaped tag would aid recovery or observation of a
tagged fish released below the dam. In con-
sidering the conditions for tag recoveries and
observations, we do not agree with this argument.
At Tumwater Dam all tags were observed in clear
water from a distance of 3 or 4 feet. Most tags
were read for numbers; thus, differentiation of tags
from above and below the dam should have been
readily apparent. This also holds true for tag
observations at Zosel Dam. On the Okanogan
River spawning grounds, tags were recovered from
dead spawned-out fish or were observed during
surveys of the river. In the latter case, biologists
identified tags from 5 to 25 feet away and recogni-
tion was easy. In fact, when viewing tagged fish
from the Tumwater Dam suspension bridge and
from the railroad bridge just below Zosel Dam,
both suspended 20 to 30 feet above the water, we
could easily discern sizes and shapes of tags.
Biologists observing fish at Rock Island dis-
tinguished, from about 40 feet away, shapes, sizes,
and colors of tags on fish in the tailrace just below
the fish way.

So far as tag colors are concerned, all tags used
below the dam had single-colored disks and single-
colored bars, streamers, or spaghetti. Tags used
above the dam had single or bicolored patterns on
the disks. It is difficult to say what the dif-
ferences in colors or color combinations mean in
terms of likelihood of recovery. Based on our
observations of hundreds of tags under many
circumstances, we believe that the tags, when
seen, can be differentiated by color and kind.

ALTERNATIVE MODELS FOR ESTIMATING
MORTALITY

Several models were considered for estimating
mortalities in addition to the one used (ratios of
recovery proportions of tagged fish from different
release areas). We were unable, however, to
accept the assumptions necessary for some. In
others, dubious and conflicting results were ob-
tained; hence, they are not given in detail in this
paper. Two models are discussed briefly.

In one model we determined the racial composi-
tion of sockeye salmon in the tagged sample by
estimating the number of 4-year-old upriver fish

from the relative abundance of 3-year-old Oka-
nogan fish in the tagged lots, and using the ratio
of fishway counts to numbers released, as an
adjustment factor in estimating the relative
abundance of Wenatchee tagged fish in different
release groups. Another model estimated racial
composition from the differences in the proportions
of 3-year-old sockeye in the populations at Rock
Island Dam and in the Okanogan River, caused
by a segment of the 4-year-old sockeye population
splitting off and entering the Wenatchee system.
In neither of these two models were definitive
results obtained regarding mortalities caused by
the dam. Mortalities were indicated for some
years and areas, not for others. Because of
these conflicting and nondefinitive results, we
feel the best approach to the problem is that

given.

MORTALITIES

Populations of anadromous salmonids lose some
members passing large dams. For years, dead
salmon have been observed floating down the
Columbia River below Bonneville Dam, ap-
parently fish which failed to pass the dam. Using
the results of experiments involving the marking
and recovery of dead salmon carcasses, Merrell
and Collins 3 estimated a salmon loss at Bonneville
Dam. Thompson (1945) found that a serious
decline in Fraser River sockeye salmon runs was
related to an area of difficult passage and to an
obstruction in the river, even though salmon
were known to pass this area each season. In a
later paper on the Fraser River sockeye salmon,
Talbot (1950) found that fish delayed longer than
14 days at Hells Gate did not reach their spawning
grounds.

The tagging experiments at Rock Island gave
conflicting results of mortalities caused by the
dam. We found no mortalities for 3-year-old
sockeye salmon when comparing recoveries of
tagged fish released above and below the dam.
We found mortalities in many experiments for
4-year-old sockeye when comparing tag returns
from above and below dam releases. In other
experiments involving these 4-year-old fish, no
mortalities were indicated. Most experiments

' Merrell, Theodore R„ and Melvin D. Collins. An investigation of adult
chinook salmon mortality in the vicinity of Bonneville Dam, 1954 and 1955,
on the Columbia River. Fish Commission of Oregon, August, 1960. 150 p.
(Contract No. DA-35-026-eng-20892, U.S. Department of Interior, Fish and
Wildlife Service.)

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

363

with chinook salmon indicated no mortalities
caused by the dam.

Residts show that mortalities caused by the
dam are neither substantial nor consistent over
the years, or that our tagging methods could not
detect mortalities accurately. Confidence limits
for the point estimates of mortalities ranged from
zero (in many instances) to about 28 percent for
the lower limits; upper limits ranged from 20 to
66 percent.

Comparatively few tagged fish used the right
ladder (also observed for untagged runs), even
when they were released near it. Apparently,
the majority of these salmon ascended other
ladders. An increased percentage of the salmon
was attracted to the right ladder in 1957 when
spillway gates on the right side of the dam were
opened during the fish migration season. Pre-
viously these were closed to reduce water turbu-
lence near the right ladder entrance. It may be
that the added flow attracts fish to this bank and
into the fishway.

While altering the right bank fishway might
induce more fish to use the right ladder, we
cannot say it would result in markedly improved
facilities with respect to mortalities.

DELAY

Delay of migrating adult salmon runs is very
important to the survival of the runs. As
Thompson (1945) and Talbot (1950) pointed out,
delays to sockeye salmon runs in the Fraser River
caused mortalities and a serious decline in the runs.
Schoning and Johnson (1956), in a study at Bonne-
ville Dam on the lower Columbia River, reported
that migrating chinook salmon were delayed 2.6 to
3 "days. The 2- to 4-day delay at Rock Island
Dam may not be important in itself, but if the
delay is multiplied by a series of dams, serious
losses of anadromous fish populations may result.

We do not know if upper river salmon runs
would survive the series of delays in migration
that may result when all Columbia River dams are
completed. It may be that delays, if short-termed
would be compensated for by easier and faster
travel through the reservoirs created by the dams.
These salmon do not spawn immediately upon
reaching the spawning areas. There is an interval
before spawning, of from 1% to 2K months after
the salmon pass Rock Island Dam. This ripening
period has been noted on other river systems.

Howard (1948) found that the period for sockeye
in Cultus Lake, British Columbia was about 1
month. Schaefer (1951) noted the time for sock-
eye in the Harrison River system of British Colum-
bia, was a month or less. The ripening period for
sockeye in Lakelse Lake, British Columbia, aver-
aged 54 days (Fisheries Research Board of Cana-
da, 1954). In the Bristol Bay area of Alaska,
some sockeye remain in the lakes up to 3 months
before spawning. The ripening period evidently
is a necessary adjunct to the migration time.

In this study at Rock Island Dam, we dis-
covered a 2- to 4-day delay to migrating salmon.
Upstream tag observations at Zosel Dam indicated
that fish tagged and released below the right ladder
were delayed longer than fish tagged and released
below the left ladder. This was confirmed by
comparing returns of left and right bank tag
releases at Rock Island for 1954. The longer
delay was absent in 1955 and 1956. Thus, while
we do not have positive evidence of a greater delay
for fish released below the right ladder, such a
delay is indicated.

Altering the right-bank fishway may lessen
delay at the dam because of the possible increased
chances of salmon finding a ladder sooner. How-
ever, the same delay pattern was noted at Bonne-
ville Dam (app.), where ladders at both sides of the
dam were designed to be equally attractive. From
this study, we cannot conclude that altering the
right bank fishway would decrease materially the
overall delay at Rock Island Dam.

SUMMARY AND CONCLUSIONS

We conducted a tagging program at Rock Island
Dam during 1953-56 to determine whether the
dam caused loss or delay of salmon passing the
dam, and whether such loss or delay was associ-
ated with the failure of fish to find and use the
dam's right bank fishway. In this study, tagged
salmon were released below the left and right bank
fishways and above the dam. Fish counters at
the dam identified different tag groups by noting
the different colors and kinds of tags on salmon
crossing the counting boards. Tags also were
identified at upstream points on migration routes
and during spawning surveys.

A comparison of upstream tag recoveries from
the different release areas gave conflicting results
regarding losses of fish. Point estimates of losses,
for some combinations of years and release areas

364

U.S. FISH AND WrLDLIFE SERVICE

(left or right bank below the dam), ranged from 0
to 42 percent, with mortalities greatest for fish
released below the right bank ladder. Tagging
data on chinook salmon indicated a loss of spring
chinooks released below the right ladder in 1956;
no loss was indicated, however, in comparing total
returns from below the dam with returns from
above the dam. For summer chinooks, tagging
data failed to show losses due to the dam.

Total tag returns at Rock Island Dam, as identi-
fied by fish counters, ranged from 64 to 86 percent
of the number released below the dam during the
experiments. Straying and mortalities may have
accounted for many of the missing tags; it was
probable also that the counters missed many of the
tags, and total returns were greater than indicated.

Tag returns at Rock Island Dam from below-
darn releases showed that although salmon were
released at both banks, the majority returned over
the left ladder. Only 12 to 14 percent of the
tagged salmon returned over the right ladder.
The tag returns corresponded closely with the
choice of ladders of the untagged populations, of
which the majority chose the left ladder for passage
and 10 to 17 percent the right ladder. Although
the salmon were taken from the ladders for tagging,
they did not learn a particlar route in re-passing
the dam; neither were they frightened from a
particular ladder during repassage of the dam.

Tagged salmon released above Rock Island Dam
arrived at upstream points 2 to 4 days earlier than
fish released below the dam. This difference in
days out corresponded to the time required for
most fish to pass Rock Island Dam after tagging,
and is termed the delay at the dam. Fish released
below the right ladder apparently were delayed
1 to 2 days longer in reaching upriver points than
fish released below the left ladder.

The days-out period at Rock Island Dam, for
sockeye released at the two banks below the dam,
was essentially the same, with most of the salmon
passing in 2 to 4 days, and the peak occurring the
third day after tagging. In 1954, right-bank
releases were delayed 1 day longer than left-bank
releases. This greater delay of right-bank releases
was not evident in 1955 and 1956. Spring chinook
peaked after 1 day-out, with the majority passing
the dam by the fourth day. The peak day for
summer chinook was the third day after tagging.
No apparent difference in days-out period at

Rock Island Dam was indicated for chinooks
released at the two banks below the dam.

An increased percentage of the run used the
right ladder in 1957, following a change in spillway-
gate operating procedures. Evidently attraction
to this ladder was increased by opening gates on
the right side of the dam next to the fishway.

On the basis of these tagging studies we found
that Rock Island Dam delayed migrating salmon
from 2 to 4 days. There is conflicting evidence of
a greater delay to fish released below the right
ladder than to fish released below the left ladder.
Data regarding mortalities gave conflicting results ;
some experiments indicated substantial mortalities
while others indicated none. While altering the
right-bank fishway may attract more fish to the
fishway, we cannot say it will necessarily improve
passage considering overall loss and delay. The
delay of 2 to 4 days may be significant when
similar delays at a series of dams are considered.

ACKNOWLEDGMENTS

Many persons in addition to staff members at
the Seattle Biological Laboratory contributed to
the tagging experiments at Rock Island Dam.
The Washington State Department of Fisheries
helped in planning the project, and provided
equipment for the investigations. The Puget
Sound Power and Light Company, and Chelan
County Public Utility District No. 1 gave valuable
assistance by providing equipment and facilities.
R. A. Fredin and D. D. Worlund of the Bureau's
Biological Laboratory in Seattle assisted with the
statistical analyses.

LITERATURE CITED

Fish, Frederic F., and Mitchell G. Hanavan.

1948. A report upon the Grand Coulee fish-mainte-
nance project 1939-1947. [U.S.] Fish and Wildlife
Service Special Scientific Report No. 55, 63 pp.
Fisheries Research Board of Canada.

1954. Pacific Biological Station. Fisheries Research
Board of Canada, Annual Report for 1953, pp.
75-99.
Howard, Gerald V.

1948. Problems in enumeration of populations of
spawning sockeye salmon. Part 1. A study of
the tagging method in the enumeration of sockeye
salmon populations. International Pacific Salmon
Fisheries Commission, Bulletin No. II, pp. 7-66.
Schaefer, Milner B.

1951. A study of the spawning populations of sockeye
salmon in the Harrison River system, with special

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

365

reference to the problem of enumeration by means
of marked members. International Pacific Salmon
Fisheries Commission, Bulletin IV, 207 pp.

Schonino, Robert W., and Donald R. Johnson.

1956. A measured delay in the migration of adult
chinook salmon at Bonneville Dam on the Colum-
bia River. Fish Commission of Oregon, Contri-
bution No. 23, 16 pp.

Thompson, William F.

1945. Effect of the obstruction at Hell's Gate on
the sockeye salmon of the Fraser River. Inter-
national Pacific Salmon Fisheries Commission,
Bulletin No. 1, 175 pp.

APPENDIX

BONNEVILLE TAGGING EXPERIMENTS

At the conclusion of the Rock Island tagging
experiments in 1954, we were confronted with
the apparent loss at the dam of many tagged
fish. What was the meaning of observing only
approximately 75 percent of the tags released
below the dam in 1954 and 64 percent in 1953?
In the following years, 65 percent in 1955 and
86 percent in 1956 of all tags released were
subsequently recorded by fish counters. Were
these percentage returns due to conditions as-
sociated with the Rock Island fishways or could
low percentage returns from tagging be expected
at any dam? In an attempt to answer these ques-
tions we decided to tag, on a small scale, below
another dam in the same manner as at Rock
Island. The objectives were to determine the
percentage and pattern of tag returns at Bonne-
ville Dam and compare them with the Rock
Island tagging data.

On July 14 and 15, 1955, 293 fish were tagged
and released below Bonneville Dam located on the
Columbia River approximately 140 miles above
the river's mouth. The procedure at Bonne-

Table A-l. — Returns at Bonneville Dam of tagged
salmon and steelhead released below the dam in 1955

I aggt'd

Returns by ladder

Returns

Species

Washington
shore

Bradford
Island

Total

No.
tagged

Sockeye
Chinook

Steelhead

Number

160

116

Number
47
9
36

Number
25
30
16

Number

'39

Percent
45.0
229 4
44.8

,".i:i

163

Percent hy

31.4

24. 2

55.6

i This is an obvious errof in species identification.

ville was the same as at Rock Island. Fish
were trapped in a ladder, transported by truck,
and tagged and released below the dam. The
experiments differed somewhat from those at
Rock Island in that the fish were released about
one mile below Bonneville on only one bank
while at Rock Island they were released about,
1,000 feet below the dam at both banks. Also,
fish at Bonneville were tagged with paired disks
and not the combination tags applied at Rock
Island.

Tag Returns at Bonneville

The number tagged and the returns at Bonne-
ville are shown in table A-l. Far more steelhead
were tagged at Bonneville than during the Rock
Island experiments. Tag returns of 55.6 percent
reported over Bonneville Dam by the fish counters
were less than for any season at Rock Island,
where percent returns ranged from 64 to 86 for
the seasons 1953-56. Nine tags were returned
from below Bonneville, six from dead fish found
on the beaches and three from fishermen. At Rock
Island the largest number of recoveries from
below the dam occurred in 1956 when seven were
recovered. Of these, five were from McNary
Dam where a trap was installed for other tagging
projects, one was returned by a sports fisherman,
and one was observed in Redfish Lake in the
Snake River system.

One feature found at Bonneville and not at
Rock Island is the ship locks through which it
is possible for fish to pass. There was no way
of knowing whether or not any tagged fish passed
the dam by this means.

As at Rock Island, the returns indicated fish
counters had trouble identifying species. This
is evident when 39 tagged chinook were reported
by the counters and only 17 had been tagged.
This same kind of error was noted at McNary
Dam where fish counters reported 23 tagged
chinooks from this same experiment.

The time-out period (time elapsing between
tagging and observation at the counting boards)
for tagged fish at Bonneville was similar to re-
sults obtained at Rock Island. Figure A-l
shows the number of days-out for all tagged fish
observed at Bonneville. The majority of the
fish passed in 2 to 5 days after tagging. There is
an inherent error in the figure because days-out
were computed from July 14, the first day of

366

U.S. FISH AND WILDLIFE SERVICE

tagging, although half the fish were tagged on
July 15. There was no way for the counters to
distinguish between the two lots. Correctly then,
many fish passed 1 day sooner than indicated.
It is notable that these results are similar to those
from the Rock Island experiments in which the
majority of fish passed in 2 to 4 days.

Figure A-2 shows the days-out by ladder at
Bonneville. Many fish (44 percent) crossed the
river to pass upstream through the Bradford
Island ladder, although the fish were trapped and
released on the Washington shore. The mean
days-out time for fish passing through the two
ladders was approximately the same: 6.6 days for
the Washington shore ladder and 6.8 days for
the Bradford Island ladder. Again, these results
were similar to those obtained at Rock Island.

Tag Returns — Bonneville to McNary Dam

Tag recoveries were obtained above Bonneville
Dam from the commercial fishery, sports fisher-
men, the Celilo Falls fishery, at McNary Dam, at
Rock Island Dam, and also from spawning ground

Figure A-l. — Number of days-out at Bonneville of tagged
fish released below the dam, 1955 season (days-out
dated from July 14).

surveys above Rock Island. For the area between
Bonneville and McNary Dams, 28 sockeye and 3
steelhead tags were returned by commercial
fishermen and the Indian dip net fishery at Celilo
Falls. Sports fishermen fishing in the various
tributaries returned tags from seven tagged steel-
head.

At McNary Dam, approximately 120 miles
above BonnevUle, 84 of the Bonneville tagged fish
were recorded at counting stations. This was

28.7 percent of the number tagged and 51.5 per-
cent of the number recorded over Bonneville
Dam. The total number of tags accounted for
from Bonneville to and including McNary counts
was 122, or 41.6 percent of the number tagged and

74.8 percent of the number reported over Bonne-
ville.

Figure A-3 shows the days-out for tagged fish
at McNary Dam. The double mode is pronounced
for each species and the modes are 5 days apart
for chinooks and sockeye. It is doubtful that the
5-day interval is the result of computing days out
from the first day of tagging when tagging oc-
curred on 2 successive days. It is more likely
that some short-term delay affected a group of
fish, possibly those tagged the second day. The
figure shows that the majority of tagged fish took
from 12 to 20 days to pass McNary Dam after
being tagged below Bonneville Dam.

Tag Returns Above McNary Dam

The Rock Island fish counters were alerted to
the particular tag applied at Bonneville and re-
corded its appearance on fish. The tags used
were paired disks of a copper color with a black
bullseye, a very distinctive color, and much

DAYS-OUT

Figure A-2. — Number of days-out by ladder at Bonne- Figure A-3. — Number of days-out at McNary Dam for
ville of tagged fish released below the dam in 1955 the three species tagged below Bonneville Dam in 1955

(days-out dated from July 14). (days-out dated from July 14).

LOSS AND DELAY OF SALMON PASSING ROCK ISLAND DAM

367

different from the tag combinations used below
Rock Island. The counters reported five sockeye
and one chinook tag of this group between August
3 and August 21. However, the counters were
apparently unable to observe and identify this
particular tag easily, for 14 tags (11 sockeye, 2
chinooks, and 1 steelhead) were recovered during
spawning ground surveys above Rock Island.

If many of the Bonneville tags (8 of 14 or 57
percent) passed Rock Island undetected, where
counters were alerted for tags of various colors and
combinations, it is likely tagged fish could pass
unnoticed at any dam. Unaccounted-for tags,
which have been released below a dam, may not
represent true mortalities of tagged fish occurring
below a dam. These data are dependent upon the
ability of fish counters to observe all tags, and for
various reasons this may not be possible.

SUMMARY AND CONCLUSIONS

A small-scale tagging experiment below Bonne-
ville Dam on July 14, and 15, 1955, and patterned
after the Rock Island experiments, gave results
similar to those obtained at Rock Island Dam.
Total tag returns at Bonneville Dam were 56

percent, or somewhat less than the 64-86 percent
returns at Rock Island for 1953-56. It is not
known if tagged fish passed Bonneville by way of
the navigation locks, thus reducing the number
available for passage through the fishways. Fish
released on one shore below Bonneville passed the
dam through both fishways with only a slight
majority passing through the Washington shore
ladder on the side they were released.

The days-out period at Bonneville compared
closely with the results obtained at Rock Island.
The majority of tagged fish passed in 2 to 4 days
at both dams. As at Rock Island Dam, the fish
counters at both Bonneville and McNary Dams had
difficulty in identifying species. More tagged
chinooks were reported at Bonneville and McNary
Dams than had been tagged.

The returns at Rock Island of the Bonneville
releases were featured by the apparent inability
of the counters to identify these tags. Six tags
were reported at the dam and 14 were recovered
on the spawning grounds above the dam. It is
suggested, therefore, that tags may pass undetected
at any dam and caution must be used in relating
unaccounted-for tags to mortalities occurring
below a dam.

368

U.S. FISH AND WILDLIFE SERVICE

OCCURRENCE IN TAMPA BAY, FLORIDA, OF IMMATURE SPECIES
DOMINANT IN GULF OF MEXICO COMMERCIAL FISHERIES1

By James E. Sykes, Fishery Biologist (Research Administration), and John H. Finucane, Fishery
Biologist (Research), Bureau of Commercial Fisheries

ABSTRACT

Populations of finfish, crabs, and shrimp were sam-
pled from August 1961 through November 1962 as part
of Tampa Bay estuarine studies. Specimens collected
were identified to species and classified as immature or
adult. Twenty-three species of major importance in
Gulf of Mexico commercial fisheries were found to
inhabit Tampa Bay during immaturity. Seasonal and
areal distribution is described for the species common to
Tampa Bay biological collections and catches in the
Gulf. Although most of these species were distributed

throughout the Bay system, Old Tampa Bay harbored
greater numbers of them than any other area. Hills-
borough Bay, an area of the system similar to Old
Tampa Bay in salinity regimen, harbored fewer impor-
tant species than any other area. Its relatively low
production is attributed to loss of the natural habitat
through human alteration. The role of the estuary in
producing and rearing species important in Gulf fish-
eries is discussed, and the need for preservation of
estuarine nursery areas is stressed.

It is becoming increasingly apparent that
estuaries play an important role in the production
of most finfish and shellfish harvested in coastal
fisheries, and that civilization influences the nutri-
ent capacity and productivity of these areas
(Skud and Wilson, 1960).

Tampa Bay is one of the larger Gulf-connected
estuaries, encompassing some 350 square miles.
The primary purpose of this report is to enumerate
and discuss species inhabiting this estuary in early
life and entering Gulf fisheries as adults. The
secondary purpose is to appraise relative species
production between areas of the Bay as an aid in
evaluating the probable effects on biota of the
various engineering projects that are being pro-
posed.

Man's ravages of estuarine areas in Florida are
progressing so rapidly that many species of fish
will disappear from these areas in the near future
(Springer and Woodburn, 1960). Pollution and

Note. — Approved for publication November 11, 1964.

1 Contribution No. 16, Bureau of Commercial Fisheries Biological Station,
St. Petersburg Beach, Fla.

engineering projects are the greatest threat to the
survival of estuarine species (Thompson, 196 1 , and
Sykes, 1964 and 1965). These projects include
harbor improvements, navigation channels, flood-
and erosion-control structures, hurricane barriers,
and fills to create new waterfront land. These
alterations result in reduced water area. Adjacent
bottom, including submerged grass flats, is de-
stroyed by dredging, and the regimen of salinity
and water temperature is changed. Sediments
are added to the water, and damaging siltation
occurs on nursery areas inhabited by commercial
and sport fish species.

Although the danger to native aquatic, animals
is recognizable, the full significance of estuaries in
the production and rearing of these organisms is
not completely understood. Odum (1960) em-
phasized the importance of conducting research at
both ends of the food chain to achieve a more com-
plete understanding of ecological systems. He
also implied that too many researchers start at a
point well up on the food chain — fish, for in-
stance— and work down. The East Gulf Estua-

FISHERY BULLETIN! VOLUME 65, NO. 2

369

rine Investigations of the Bureau of Commercial
Fisheries include studies of nutrients and primary
crops of estuarine waters, as well as studies of the
dependence of animals such as finfish, crabs, and
shrimp upon nutrients and planktonic organisms
(Sykes, 1965). The research, therefore, is being
conducted near both extremes of the food chain
and at intermediate points. Although the value
of an estuary to our social and economic system
should not be measured entirely in terms of its
contribution to a commercial fishery, the harvest of
edible and industrial species is a major consider-
ation and is logically one of the factors motivating
estuarine research. It was, therefore, important
in our investigations to determine and study the
important commercial species in Gulf of Mexico
fisheries that utilize estuaries as rearing and devel-
opmental areas.

TAMPA BAY, WEST FLORIDA COAST, AND
GULF FISHERIES

In evaluating the importance of Tampa Bay as
a nursery area for commerical species, the size and
economic value of commercial catches of the Gulf
of Mexico should be considered.

Fisheries in the Gulf have grown notably in the
past quarter-century. In 1936, 187 million pounds
or 4 percent of recorded landings were from the
Gulf; in 1961, this area yielded 1.3 billion pounds
or 27 percent of total recorded U.S. fishery land-
ings (Power, 1961). Of the average annual Gulf
catch for 1958, 1959, and 1960, 12 percent
(131,369,000 pounds) was landed on the west
coast of Florida (Power, 1960, 1961, 1962a, 1962b).
Size and value of the west Florida landings were
second to Texas and exceeded Louisiana, Missis-
sippi, and Alabama.

A summary of valuation showed that the total
U.S. exvessel landings in the Gulf of Mexico were
worth an annual average of $85 million for the 3
years cited. West Florida landings accounted for
$20 million of that amount. Catches landed in
the three counties surrounding Tampa Bay
(Pinellas, Hillsborough, and Manatee) averaged 26
million pounds for the 3 years and accounted for
$6 million of the total (U.S. Fish and Wildlife
Service, 1959; Rosen, 1959; Rosen and Robinson, 1960).
Pinellas County is dominant among the three
((unities in landings of seafood. It has the most
extensive offshore commercial and sport fishing on
the Florida west coast. The county supports the

MULLET put"']

SPANISH MACKEREL

POMPANO

MULLET (ttrlpad)

GROUPER

JACK fcrtvollt)

PERMIT

SPOT

SEATROUT (tpottad)

MOJARRA dandpirch)

SLUE CRAB

SEATROUT (vhIL)

SHEEPSHEAO

SHRIMP

OYSTERS

BLACK DRUM

MENHADEN

■■ WEST FLORIDA COAST
||B TAMPA BAY AREA

■

PERCENTAGE OF 0ULF CATCH

Figure 1. — Three year average (1958-59-60) of commer-
cial landings on the Florida west coast and in Tampa Bay
compared with total Gulf catches.

second largest fleet of commercial boats, the third
largest fleet of party boats, and the sixth largest
fleet of charter boats in the State (Moe, 1963).

Catch data were assembled for the important
commercial species common to Gulf of Mexico,
Florida west coast, and Tampa Bay fisheries (table
1). For a determination of percentages of the
total Gulf catch landed on the Florida coast and in
Tampa Bay (fig. 1), annual landings of these
species were averaged for the three divisions of
Gulf fisheries for the years 1958-60.2 Two of the
leading Gulf species, menhaden and oysters, were
included even though their commercial catch in the
Tampa Bay area was negligible.

More than 90 percent of the Gulf landings of
silver mullet, Spanish mackerel, pompano, striped
mullet, and grouper were made on the Florida west
coast (fig. 1). Annual landings of these species
for 1958-60 averaged 12 million pounds in Tampa
Bay, 45 million pounds on the west coast, and
47 million pounds in the Gulf. Species comprising
25-90 percent of Gulf catches landed on the west
coast were crevalle jack, permit, spot, spotted
sea trout, mojarra, blue crab, red drum, white
sea trout, and sheepshead. Annual landings of
these species for the 3 years averaged 1.5 million
pounds in Tampa Bay, 19 million pounds on the
west coast, and 38 million pounds in the Gulf.
Landings on the west coast of the two most impor-
tant commercial species in the Gulf (shrimp and
menhaden) were each below 25 percent of total

1 The species in table 1 and Tib. 1 are listed according, to percentage of ( lulf
catch landed on the Florida west coast rather than rank in the total Uulf catch.

370

U.S. FISH AND WILDLIFE SERVICE

Table 1. — Average of 1958-60 annual landings of selected
commercial species in Gulf of Mexico fisheries

Mullet (silver)2

Spanish mackerel

Pompano

Mullet (striped)

Grouper '

Jack (crevalle)—

Permit

Spot.

Sea trout (spotted)...
Mojarra (sandjKTCh)2.

Blue crab

Red drum...

Sea trout (white)

Sheepshead

Shrimp3

Oysters

Black drum

Menhaden 2

Total 967,116,300

Average

Gulf
landings

Pounds

690, 300

4,676,300

506,700

32, 962, 300

S, 638, 000

1,011,000

40,300

250, 300

4,817,700

282,700

29, 199, 000

2. 009, 300

210, 700

378,000

190, 860, 700

13. 409, 000

1,651,000

678, 523, 000

West
Florida
landings

Pounds
690, 300

4, 645, 000
486. 000

31, 293. 700

5, 276. 000
890, 100

30, 200

188,700

2,821,300

150, 000

13, 748, 300

712, 100

69,700

107, 200

40, 774, 000

1,380,300

129,000

11, 092, 600

114,484,500

Average
3-county '
landings

Pounds

137, 900

364,900

66,200

8, 885, 700

1,993,200

92,200

6,900

38,400

652, 300

2.S. 91 III

468. 900

152,900

54,400

23,900

12,357,900

1,900

43,900

4,000

25, 374, 400

i Pinellas, Hillsborough, and Manatee.

2 When several species were reported under a single common name by Fed-
eral and State statistical agents, they were listed accordingly regardless of
the number of species involved.

Gulf catches. Oysters and black drum also were
included in the 0-25 percent range. Average
annual landings of these four species were 12
million pounds in Tampa Bay, 53 million pounds
on the west coast, and 884 million pounds in the
Gulf.

BIOLOGICAL COLLECTIONS

Monthly fish collections were made in the
Tampa Bay area during August 1961 through
November 1962. The study area encompassed
the entire Tampa Bay system extending from the
mouth throughout Old Tampa and Hillsborough
Bays (fig. 2). The hydrological influence of the
estuary extends into the Gulf for an undetermined
distance; however, in this report only the semi-
enclosed waters of Tampa Bay are regarded as
estuarine habitat.

Gear used in collecting specimens consisted of
30-, 50-, and 70-foot minnow seines, a 10-foot
shrimp trawl, a 16-foot balloon trawl, a 3 x 3-foot
push net and a 6-foot cast net. Springer and
Woodburn (1960) used similar seines, push nets,
and, in addition, a roller frame trawl. In a quali-
tative assessment of the species occupying Tampa
Bay and the sizes of these species, the collections
by all types and sizes of gear were utilized and
included in this report. When quantitatively
describing occurrence by species and area, data
were restricted to collections from the 10-foot
shrimp trawl and the 50-foot seine. Duration of

82*50'

40' 82*30'
1 I

j* MILLSBOfiOUGH R

OO'

r*&~ \ "\ S „n j

L ■> m \ 2drY*~~^

50-

\jh *%""" ^»J / °1>

o ^30-

\)i a/U -*--0 r

(J >&

* \ «Mfo ~ -. /

b V Jk ^ 't~i

111

\rV' '""**•" Co n jJ

%\ s. Jo * .•••fes5==

•">

f ' "»

9) jf (gUlTTLE MANATEE M

40'-

ii '"

\ <l J SAMPLING STATIONS

*^\ *T^Vr^ ** ~~ BEACH SEINE
(JO I * ^Vl O -">««-

4r Jl

27"_
30'

xS^f^^^

Figure 2. — Study areas and station locations in Tampa
Bay.

each trawl haul was 10 minutes at 3-4 knots.
Seine operation was as similar as possible at each
station throughout the study period to insure
comparability of results in catch per unit of effort.

Sampling stations were stratified throughout
the Bay to collect specimens from the full salinity
range. For comparison of species occupancy by
area and salinity range, the stations were grouped
to represent four areas based on salinity data from
Saloman, Finucane, and Kelly (1964): Area I—
lower Tampa Bay (salinity range, 21.92-37.16 %o,
mean — 31.95%Q); Area II— central Tampa Bay
(salinity range, 15.88-33.53°/0o, mean— 24.48%o) ;
Area III — Old Tampa Bay (salinity range, 0.09-
31.83°/oo, mean— 24.53 %o); and Area IV—
Hillsborough Bay (salinity range, 1.58-30.46%o,
mean— 23.63%o) (fig. 2).

The separation of specimens into immature or
adult classes was based upon (1) observations of
gonad development in relation to length frequency
data compiled at the Bureau of Commercial
Fisheries Biological Station at St. Petersburg,
Beach, (2) published data on individual species

IMMATURE SPECIES IN TAMPA BAY

371

(Anderson, 1957; Anderson, 1958; Gunter, 1945;
Guest and Gunter, 1958; Gunter and Christmas,
1960; Frisbie, 1961; Fields, 1962; Springer and
Woodburn, 1960; and Rathbun, 1930), and (3)
personal communication (Bonnie Eldred — Florida
State Marine Laboratory, St. Petersburg, Fla.
and George H. Rees — Bureau of Commercial
Fisheries Biological Laboratory, Beaufort, N.C.).
Specimens were preserved in 10 percent
formalin, and fish were measured to the nearest
millimeter in standard length. The carapace of
crabs (width) and shrimp (length) was measured
by micrometer to the nearest one-tenth millimeter.

SUMMARIZED DATA

Fish and crustaceans from all stations and gear
were classified as immature or adult to aid in
assessing the utilization and dependency of each
species on the estuary during early life. Although
some adults were captured — and Tampa Bay sport
fisheries take large numbers of them — specimens in
sampling gear were limited largely to small forms.
Size ranges and occurrence by section of Tampa
Bay were noted (tables 2-5).

Trawl and seine catches of the commercially
important finfish, shrimp, and crabs were compiled

Table 2. — Size by season of commercial species of fish and crustaceans in Lower Tampa Bay — Area I, December 1961-

November 1962

WINTER (Dec.-Feb.)

SPRING (Mar.-May)

SUMMER (June-Aug.)

FALL (Sept.-Nov.)

Species

Immature

Adult

Immature

Adult

Immature

Adult

Immature

Adult

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

Mugil curema
(silver mullet).. .

Mm.

14
58

Mm.
51-107

10-90
35-41

Mm.

2
444

Mm.
114-121

16-161

94
•133-158

42-167

Mm.

Mugil trichodon
(silver mullet) .

17-157

34-113

Scomberomorus
maculatus
(Spanish

Trachinotus caro-

2
64

101

20
112

29
917

93
1

11
11

44-56
•23-87

50-137

160-263

84-92

25-52

21-83

•8. 5-68. 5

61-142

19-91
14-54

26-54
32

46. 0-89. 4

Mugil cephalus
(striped mullet)_.

817

17-32

1,234

21-86

230

41
15

90-154
160-195

Mycteropetca

Epinepkdus motio

Caranx hippos

1
9

888

9
322

5
10

40
38

3
290

120-347

150

"60-74

12-147

43-134

7-54

14-^47
50-63

15. 1-82. 8
14. 8-95. 6

18-55

81-170
4. 8-20. 0

85
1.866

336

97
95

1,070

37-90

35-109
•24-144

94-130

13-140

16-53

15-53
39

12. 3-89. 0
11. 7-%. 2

19-30

16-165

51-155
4. 3-20. 0

170

Trachinotus sp.

Leiostomus xanthu-
rus (spot)

Cynoscion nebulo-
sus (spotted

151-175

823

151

21-143

•5.9
24-54

31-49

150-175

2
138

150-175

180-448
55-90

55-111

307

147-248
180

Eucinostomus gula
(mojarra) .

Eucinostomus
argenteus
(mojarra).

Diapterus plumieri

172
7

57-105
60-103

99
40

55-115
65-115

55-92
55-80

Callinectes sapidus:
(blue crab):

3
1

4
11

98. 0-140. 0
168.0

270

180-225

185-325
20. 5-26. 6

5
10

46. 0-80. 9
42. 8-92. 1

100-124

27-50

19-21
11.1-19.9

4
1

96. 3-150. 0
138.0

97.3

6
2

131. 0-202. 2

Sciaenops ocellata
(red drum)

Cynoscion arenar-
ius (white

15
1

175-210

180-275

20. 7-28. 7

•593

14
664

5
3

25-75

25-M

5. 2-18. 0

116-128

70-78

71-75

166-206

10
5

172 223

Archosargus proba-
tocephalus
(sheepshead)

172-285

Penacus duorarum

(pink shrimp)

Pogonias cromis

20. 2-24. 2

Brevoortia patronus

1
2

75
25-76

Brcvoortia smilhi

135-185

•From Springer and Woodburn (1960).

372

U.S. FISH AND WILDLIFE SERVICE

Table 3. — Size by season of commercial species offish and crustaceans in Central Tampa Bay — Area II, December 1961-

November 1962

WINTER (Dec.-Feb.)

SPRINO (Mar.-May)

SUMMER (June-Aug.)

FALL (Sept.-Nov.)

Species

Immature

Adult

Immature

Adult

Immature

Adult

Immature

Adult

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

Mugil curema

3
53

Mm.
122-153

28-143

Mm.

Mugil trichodon

175-234

121-137

Scomberomorus
maculatus
(Spanish

Trachinotns caroli-

Afugil cephahis

(striped mullet) .
Mycteroperca

187

18-24

157

24-71

53-87

Epinephetus morio

Caranx hippos (cre-

25-45

•186-246

Trachinotus sp.

Leiostomus xan-
thurus (spot)

Cynoscivn nebu-
losus (spotted
seatrout)

Eucinostomvs gula

256

3
241

17-30

52-86
17-49

36-54

176

24-60

64-130

18-132
31-53

42-54

165-180

54
423

151
1

25
13

422

86-125

27-80
15-53

21-53
47

14. 3-69. 0

15. 5-68. 0

14-37
35

65-81
5. 0-19. 7

152 165

30
42

66-80
57-100

366
79

19-52
26-52

44
51

57-85
55-95

131
20

55-93
59-101

46
38

57-90

Eucinostomus
argenteus

56-106

Diapterus plumieri

Callinectes sapidus
(blue crab) :

4
7

13. 3-46. §
18. 5-50. 9

21-71

...

3
9

46. 0-63. 0
40.2-110.0

92. 0-144. 0

10
3

12. 7-78. 0
54. 2-65. 7

90.0-113.5

2
4

135. 0-154. 5

145. 0-200. 0

Sciaenop.t ocellata

(red drum)

Cynoscion arenarius

6
334

14-125

24-30
5. 3-19. 5

165-200

184-227

Archosargus
probatocephahts

11
3

19-35
12. 8-16. 0

Penaeus duoraTum

(pink shrimp)

Pogonias cromis

6. 3-15. 1

29. 7-31. 8

23.2

20.3

Brevoortia patronus

Brevoortia smithi

31-36

•43.8

170-180

•From Springer and Woodburn (1960).

by month and area to compare abundance of im-
mature animals (table 6). Catches included were
from four selected trawl stations and two selected
seine stations in each of the four sampling areas
fished monthly. The catches of these six fishing
operations in each area during 1 month represent
one unit of effort. Thus, 72 hauls (12 standard
units of effort) took place in each of the four areas
during a 12-month period. The data allowed
comparison of abundance between individual
species by season and area (fig. 3). For this
estimate, effort expended and numbers of speci-
mens caught per species were combined for
3-month intervals; winter, spring, summer, and fall.

DISCUSSION

Most of the species landed by Gulf of Mexico
commercial fisheries inhabit estuaries as immature,
developing forms. It is assumed, therefore, that
these estuaries are prime suppliers for the Gulf
fisheries. Power (1962b) stated that five species —
menhadan, shrimp, crabs, oysters, and mullet —
comprised a catch of 1,131 million pounds or 89.3
percent of the Gulf commercial catch in 1960.
Our investigations showed that 23 commercially
important species including the dominant ones
listed by Power (1962b) occupy Tampa Bay while
immature.3 All of these species are caught as

'Oysters are included in this numher but were not collected by sampling
gear.

IMMATURE SPECIES IN TAMPA BAY

373

Table 4.

-Size by season of commercial species of fish and crustaceans in Old Tampa Bat/ — Area III, December

1961-November 1962

WINTER (Dec.-Feb.)

SPRING (Mar.-May)

SUMMER (June-Aug.)

FALL (Sept.-Nov.)

Species

Immature

Adult

Immature

Adult

Immature

Adult

Immature

Adult

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

Mugil curema

Mm.

1
7

Mm.

41-134

Mm.

22-84

Mm.

Mugil trichodon

15-101

159
1

15-101
•36

Scomberomorus
maculatus (Span-
ish mackerel)

Trachinotus caroli-

Mugil cephalus

1,011

17-32

155-165

3,434

21-130

511

42-122

92-126

Alycteroperca micro-

Epinephelus morio

Caram hippos

Trachinotus sp.
(permit)

Leiostomus xanthu-
rus (spot) --

Cynoscionnebulosus
(spotted sea-

1,279

8
175
153

40
21

12-135

36-105
30-52

13-50
55-75

12. 3-88. 0
16.0-108.0

24-89

55-140

125
5. 7-19. 5

37
29

151-157

210
62-90
59-85

3,170
1

21-139
29

149-190

180
55-84
56-86

486

158

728

19
16

40-137

14-147
32-50
21-46
15-65

39. 0-87. 0
12.5-115.8

5
8
11
7

59
11

155-189

165-225

65-73

57-74

87-103

92.0-140.0
130.0-155.0

262

253

123

30
36

147

164

478

66-133

33-147
26-48

12-50
27-74

18. 0-83. 5
16.0-125.0

14-62

20-118

66-132
3. 5-19. 8

197

17
52

150-185

Eucinostomus gula

Euanostomus ar-

genteus (mojarra).
Diapterus plumieri

34-50

56-83

Callinectes sapidus
(blue crab):

8
1

93. 6-195. 0
150.0

47
52

7
4

40. 0-88. 7
20. 0-127. 0

102-114

35-49

16-30
13.3-19.8

16
2

90. 5-180. 0
135.0-145.0

38
2

90.5-163.0

150.0-152.0

Sciaenops ocellata

Cynoscion arenarim
(white seatrout)..

Archosargus proba-
tocephalus

192-198

210-258

307

124

33
8

17-95

40-63

6. 5-18. 8

37-156
•66-110

58-115
•55-108

59-91

155-195

1
9

160-215

171

Penaeus duorarum

(pink shrimp)

Pogonias CTomis

20. 5-30. 1

21. 1-30. 1

20. 7-28. 9

20. 5-25. 8

1,064
135

•20-75
24-74

Brevoortia patronus

•22.1

105

Do....

Brevoortia smithi

263

21-46
•19-29. 1

•From Springer and Woodburn (1960).

adults in Gulf of Mexico commercial fisheries and
Tampa Bay sport fisheries. Few constitute im-
portant commercial fisheries in Tampa Bay. The
significance of the estuary lies more in the growth
of species for later harvest in Gulf fisheries than
in catches of adults in nursery areas.

Shrimp comprise the most valuable fishery in the
Gulf of Mexico (Power, 1962b). Commercial
catches consist primarily of three species: the
brown shrimp, Penaeus aztecus; the white shrimp,
P. setiferus; and the pink shrimp, P. duorarum
(Kutkuhn, 1962). Young of several species in
developmental stages have been found in Tampa
Bay (Eldred, Ingle, Woodburn, Button, and Jones,
1961) — the penaeid shrimp, Trachypeneus con-

strictus and P. duorarum, and the rock shrimp,
Sicyonia laeingata and S. typica. These and one
additional penaeid species, Trachypeneus similis,
were identified in our collections (Saloman, 1964).
The important Gulf shrimp collected in Tampa
Bay was P. duorarum. It is estimated that 75
percent of the shrimp brought to dock in the three-
county area surrounding Tampa Bay are P.
duorarum and 25 percent P. setiferus. Ninety-
eight percent of the total is actually caught on
the Campeche grounds (personal communica-
tion, Robert Benton — Bureau of Commercial
Fisheries Biological Laboratory, Galveston, Texas).
In Tampa Bay, P. duorarum is caught for a bait-
shrimp market only. During October 1961

374

U.S. FISH AND WILDLIFE SERVICE

Table 5. — Size by season of commercial species of fish and crustaceans in Hillsborough Bay — Area IV, December 1961-

November 1962

WINTER (Dec.-Feb.)

SPRING (Mar.-May)

SUMMER (Junc-Aug.)

FALL (Sept.-Nov.)

Species

Immature

Adult

Immature

Adult

Immature

Adult

Immature

Adult

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

No.

Size range

Mugil cuTema

Mm.

Mugil trichodon
(silver mullet)

Scomber omor us
maculatus (span-

29-35

71-96

15-25

240

Trachinotus caro-

Mugil cephalus

(striped mullet. . .
Alycteroperca

19-100

22-88

56-115

121-153

Epinephelus morio

Caranx hippos

Trachinotus sp.

Leiostomus xan-
thUTUS (spot)

Cynosdon nebulosus
(spotted sea-

5
2
70
81

6
131

18-30

91-109
19-53
25-50
33-77

40. 4-79. 6
28. 0-87. 2

27-72

114-153

111-170
10. 5-18. 4

367

27-137

158-176

25
5

70-135
42-88

155-175

1
1

156
14

13
7

95-110

16-51

47-74

11. 8-87. 3
20.5-115.0

21-55

17-142

93-167

5. 9-19. 4

165

145-165

Eucinostomus gula
(mojarra)..

Eucinostomus ar-
genteus (mojarra) .

Diapterus plumieri
(mojarra).

Callinectes sapidus
(blue crab):

7
4

1
2

75-85

58-85

131-145

166.0
132. 0-175. 0

42
35-51

63-91

73
3

24-50
30-45

53. 2-87. 2

60-68

30
19

11. 0-80. 2
42. 0-120. 0

92. 0-153. 0

97. 1-149. 0

23
1

93. 0-163. 0

Sciaenops ocellata

(red drum) . - .
Cynosdon arenarius

(white seatrout)..
Archosargus pro-

batocephalus

(sheepshead)

Penaeus duorarum

(pink shrimp)

Pogonias cromis

170-221

14
1

18-45

170-210

5
3

17-83

30-133
9. 9-17. 4

48-114

181

166-248

29. 1-33. E

20. 6-27. 3

27S

BrevooTtia patronus

5J
23-2S

BrevooTtia smithi

241

179

33-6E

87-93

159-172

Table 6. — Numbers of immature specimens of fish and
crustaceans taken in sampling gear by month, December
1961-November 1962, Tampa Bay, Fla.

Numbers o( fish

, shrimp, crabs

Total per

Area I

Area II

Area III

ArealV

month

1961
Dec

102

315

182

252

674

346

325

227

76
414
261
277
259
107
157
122
215
531
258

103

539

627

1,975

2,016

725

1.02S

641

493

249

116

14
36

164

254
96

260
44
88

100
36
88

214

1961

731

Feb

1,392

2, 582

2,569

1,093

1,428

July --

1,094

1,377

Sept

737

Oct .

1,141

689

Total per area.. .

2.545

2,699

8,588

1,215

15, 047

Catch/unit effort

212.1

225.0

715.7

101.2

through April 1962, 71,000 pounds of bait shrimp
were caught in this fishery (Saloman, 1965).

Eldred et al. (1961) described recruitment of
postlarval P. duorarum into Tampa Bay and a
movement of larger shrimp from the Bay to
offshore waters. Their observations on migration
and our collections of larvae suggest that at least
part of the Gulf shrimp fishery for that species
depends upon populations developed in Tampa
Bay.

Menhaden ranks first in size of catch and next
to shrimp in value for all species landed in the
Gulf of Mexico. The fishery in the Gulf depends
upon catches of Brevoortia patronus (Gunter and
Christmas, 1960). B. smithi and B. gunteri have
been found in the Gulf, and probably comprise a
very small fraction of the commercial catch.

There is no menhaden fishery in Tampa Bay,
and landings of menhaden on the Florida west
coast are minor in relation to total Gulf landings.

IMMATURE SPECIES IN TAMPA BAY

375

SILVER MULLET
5H-VES MULLET
STRIPED MULLET

SfOTTEO SE»'

ARE* I

■ re* n

..i

MCA re

.|.|.|.

,|,|,|.

, rr

1 | I | ■ | .

ODD

□

ODD

■

a a

■ ■

■

□

a a

d a

□

■

□

□ □

D O ■

■

□

■

a □

■

a a

a o a

□

D D

D □

□

D D D

□

■

D D

a □

□

a □

a a ■

■

a a

□

a a

■

■ D

Figure 3. — Occurrence of immature commercial species of
fish and crustaceans by season and area, Tampa Bay,
Fla., December 1961-November 1962.

Gunter and Christmas (1960) and Reintjes (1961)
observed that menhaden spawn at sea and sub-
sequently move as larvae into estuaries which
serve as nursery areas for further development.
Collections in Tampa Bay by our staff and by
Springer and Woodburn (1960) showed that
Tampa Bay is a rearing area for two species of
menhaden: B. patronus and B. smithi. B. smithi
was more abundant and more widely distributed
in our samples than B. patronus; the reverse of
their occurrence in Gulf catches. Suttkus (1958)
stated that B. smithi occurs in the eastern Gulf
and that B. patronus overlaps B. smithi in the
northeastern Gulf at Cedar Keys, Fla. Tabb
and Manning (1960) reported only one species,
B. smithi, from Florida Bay in the southern portion
of the State. These findings suggest that normally
B. smithi would be more abundant than B. patronus
in central Florida or the Tampa Bay area.

Mullet ranked third in pounds landed in the
Gulf and second both in Tampa Bay and on the
Florida west coast. Heavy dependence upon the
estuary was exhibited in that three species, Mitgil
cephahis, M. trichodon, and M. curema, were
found in immature and adult stages. The striped
mullet, At. cephabis, is dominant in Bay catches
(Rosen and Ellis, 1958).

The blue crab, CaUinectes sapidus, besides being
prominent in Gulf fisheries, is harvested commer-
cially in Tampa Bay. Also, it is the object of

a large sport fishery. The species forms the most
rapidly expanding fishery in Florida (Rosen and
Robinson, 1960). Approximately 50 percent of
the reported Tampa Bay landings (table 1) were
actually caught in the Bay, and the remaining
50 percent were caught in Citrus County to the
north of Tampa Bay and adjacent to the Gulf of
Mexico.

C. sapidus was the dominant portunid in collec-
tions of metamorphosed and identifiable specimens.
Numerous portunid zoeae and megalops also were
taken. We were unable to make positive species
identification at these stages and therefore cannot
estimate the proportion of C. sapidus in the
collections. Sandoz and Rogers (1944) stated that
a salinity range of 23-30%o is ideal for hatching
blue crabs. Thus, from a salinity standpoint,
the Bay appears to offer a favorable environment
for hatching and development of blue crabs.
This fact and the presence of adult blue crabs as
well as portunid larvae led us to believe that the
blue crab is reared within the confines of Tampa
Bay. In addition to mature adults, the young
identifiable metamorphosed forms (50-mm. cara-
pace width) which inhabit the Bay are most
abundant in winter.

The American oyster (Crassostrea virginica) is
an estuarine resident and supports relatively
small but growing commercial and sport fisheries
in Tampa Bay. The actual harvest in the Bay is
probably many times larger than the reported
harvest (table 1). A portion of the beds is public,
and fleets of small, privately owned boats tong for
oysters there. In recent years, interest has been
generated toward the possibility of increasing the
numbers and sizes of the beds in Tampa Bay.
Decreased oyster production in Chesapeake Bay
has brought some oystermen into Florida from
that area.

Of the 19 species of fish and crustaceans (fig. 3),
13 were taken in all four sections of Tampa Bay.
This indicates that all of the Bay is used as a
nursery area. Eighteen species were taken in the
lower, high salinity portion of the Bay (Area I),
13 in the central portion (Area II), 15 in Old
Tampa Bay where lowered salinities prevail
(Area III), and 15 in Hillsborough Bay (Area IV),
also an area of reduced salinity. The com-
mercially important species of fish, shrimp, and
crabs are euryhaline and, as expected, were dis-
tributed throughout the Bay system. The differ-

376

U.S. FISH AND WILDLIFE SERVICE

ences among numbers of species inhabiting sections
of the Bay appeared to be of little or no con-
sequence. This appraisal, however, is exclusive of
those species not considered to be of commercial
importance in this report.

Catch per unit of effort data made it possible to
determine whether immature animals had a prefer-
ence of habitat among areas of the Tampa Bay
system (table 6). An overwhelming preference
was apparent for Old Tampa Bay (Area III)
where there were three times as many total animals
as in either Lower or Central Tampa Bay (Areas I
and II) and seven times as many as in Hillsbor-
ough Bay (Area IV). Abundance in Area III
exceeded that of Areas I, II, and IV during 9
months out of 12. Although peak abundance
varied between areas and time periods, March and
April produced the greatest number of specimens
per unit of effort from the collective areas.

Data on abundance of individual species by
area and season also indicate an areal preference
(fig. 3). Seven species were taken in numbers
greater than 100 during at least one season (three
units of effort) in Area III, five in Area II, four in
Area I, and two in Area IV. The data indicate,
therefore, that Area III (Old Tampa Bay) pro-
duces or develops more individuals during a greater
portion of the year than any other area of the
Tampa Bay system, and that Hillsborough Bay is
the least productive of commercially important
species.

Based on the known salinity preference of many
euryhaline animals, it was expected that the
greatest abundance of important species would be
found in the low salinities of Old Tampa and Hills-
borough Bays. Pearson (1929) and Gunter
(1945, 1950) showed that a cycle of spawning,
growth, and movement bore a distinct relation to
salinity for many valuable fishes and invertebrates
on the Gulf of Mexico coast. Salinity lower than
that which is characteristic of the ocean is one of
the requisites in early development of these ani-
mals. Abundance in Hillsborough Bay, however,
was not nearly as great as in Old Tampa Bay.
Because annual salinity patterns of Hillsborough
Bay and Old Tampa Bay are similar, the difference
in abundance of valuable species between the two
areas must result from other environmental
factors.

The introduction of industrial and domestic
sewage is common in Hillsborough Bay. Natural

flushing has not kept pace with the deposition of
the effluents and has resulted in the accumulation
of silt-size sediments throughout the Bay. Nox-
ious compounds in solution, unstable and un-
inhabitable sediments, and insufficient dissolved
oxygen appear to have contributed to a decline in
Hillsborough Bay fisheries within a relatively short
period of time.

As a nursery area for fish and crustaceans, Hills-
borough Bay is no longer productive. Com-
mensurate with alterations in bottom type and
water quality, littoral areas which once supported
a luxuriant growth of marine grasses are now
barren except for the seasonal appearance of some
red and blue-green algae.

In contrast, Old Tampa Bay remains in a
relatively undisturbed state supporting blue crab,
bait shrimp, and oyster fisheries, and serving as a
nursery area for estuarine dependent fauna. Al-
though industrial and residential interests con-
tinually threaten this area, it is vegetated with
turtle grass (Thalassia testudinum), shoal grass
{Diplanthera wrightii), cord or manatee grass
(Syringodium Jiliforme), the red mangrove (Rhiz-
ophora mangle) , and the black mangrove (Avicennia
nitida) (Springer and Woodburn, 1960). The
emergent vegetation aids in controlling the intro-
duction of particulate detritus in surface water
run-off before it enters the Bay.

Biologically, the water quality is good, and the
predominantly firm sediment pattern creates a
substrate suitable for the habitation of dense ag-
gregations of benthic invertebrates. The sta-
bility of the bottom also promotes water clarity
necessary for the existence of dense stands of
marine algae and sea grasses which extend around
the entire periphery of the area. The^ algae-
sea grass ecosystem appears to be absolutely
essential for survival and growth of juvenile stages
of many commercially important species.

We conclude that the relatively undisturbed
conditions of Old Tampa Bay and the fact that its
salinity distribution is ideally suited to the de-
velopment of many euryhaline fishes are responsi-
ble for its comparatively good productivity.

Many species recorded as inhabiting the estuary
were omitted from our lists in this report. Some
of these contribute indirectly but significantly to
commercial fisheries by serving as food for market-
able species. An example of an outstanding forage
species is the scaled sardine (Harengula pensa-

IMMATURE SPECIES IN TAMPA BAY
774-711 O — 66 6

377

colae) . It is produced in and inhabits the Tampa
Bay area in great abundance throughout most of
the year. The sardine is utilized heavily as a live
bait in Tampa Bay and the adjacent Gulf areas.
Other forage species abundant in the estuary are
the tidewater silverside (Menidia beryllina), the
bay anchovy (Anchoa mitchilli) , the pinfish (Lago-
don rhomboides), the thread herring {Opisthonema
oglinum), and the silver perch (Bairdiella ehrysura).

The number of species of finfish, shrimp, and
crabs recorded from the Tampa Bay area now
stands at 265 (Springer and Woodburn, 1960;
Dragovich and Kelly, 1964). Most of these prob-
ably occupy an important ecological niche in the
estuary and supply food to commercial and sport
species of both Gulf and Bay. Obviously, a por-
tion of the harvest of major fisheries in the Gulf is
connected directly to the production and develop-
ment of young forms in Tampa Bay. This is
especially true of species found in catches of the
eastern Gulf or on the Florida west coast. This
estuary, of course, is not the only one important
in the role of supplying Gulf fisheries. Sykes
(1965) estimated that some 7,500 square miles
or 4.8 million acres of estuarine area exist on the
periphery of the Gulf.

The general public tends to view Tampa Bay
either as an area of good but declining sport fishing
or as an area for waterfront homesites. The present
and future importance of Tampa Bay as a food
source should be taken into account when pro-
posals are filed for permission to enclose areas with
bulkheads or create land masses in the estuary.
This is especially true when such structures will
divert currents, allow encroachment of high-
salinity waters into upper areas, or otherwise sig-
nificantly alter rearing areas of the species
discussed.

SUMMARY

Biological collections showed that the five most
important species in Gulf of Mexico commercial
fisheries inhabit Tampa Bay in immature stages
of development. Eighteen species of less impor-
tance in Gulf catches were also found in immature
stages in the Bay. The qualitative distribution of
species exhibited little difference between salinity
range and area of the Bay system but numerically
Old Tampa Bay, an area of relatively Low salinity
contained the greatest number of animals. The
importance of Tampa Bay as a nursery area for
species of fish, crustaceans, and mollusks com-

prising the most valuable portions of the commer-
cial fisheries in the Gulf has not been stressed in
the past. This role now must be recognized be-
cause of acceleration of engineering projects in the
estuary that impair its value as a nursery ground.

ACKNOWLEDGMENT

Thanks are expressed to Robert M. Ingle,
Florida State Board of Conservation, and his labo-
ratory staff for their cooperative spirit during this
and other studies of the Tampa Bay system.

LITERATURE CITED

Anderson, William W.

1957. Early development, spawning, growth, and
occurrence of the silver mullet (Mugil curema)
along the south Atlantic coast of the United States.
U.S. Fish and Wildlife Service, Fishery Bulletin,
vol. 57, No. 119, pp. 397-414.

1958. Larval development, growth, and spawning
of striped mullet (Mugil cephalus) along the south
Atlantic coast of the United States. U.S. Fish
and Wildlife Service, Fishery Bulletin, vol. 58,
No. 144, pp. 501-519.

Dragovich, Alexander, and John A Kelly, Jr.

1964. Ecological observations of macro-invertebrates
in Tampa Bay, Florida, 1961-1962. Bulletin of
Marine Science of the Gulf and Caribbean, in vol. 14,
No. 1, pp. 74-102.

Eldred, Bonnie, Robert M. Ingle, Kenneth D.

Woodburn, Robert F. Hutton, and Hazel Jones.

1961. Biological observations on the commercial
shrimp, Penaeus duorarum Burkenroad, in Florida
waters. Florida State Board of Conservation,
Professional Papers Series No. 3, 139 pp.

Fields, Hugh M.

1962. Pompanos (Trachinotus spp.) of south At-
lantic coast of the United States. U.S. Fish and
Wildlife Service, Fishery Bulletin, vol. 62, No.
207, pp. 189-222.

Frisbie, Charles M.

1961. Young black drum (Pogonias cromis) in tidal
fresh and brackish waters, especially in the Chesa-
peake and Delaware Bay areas. Maryland Depart-
ment of Research and Education, Chesapeake
Science, vol. 2, No. 2, pp. 94-100.-
Guest, William C, and Gordon Gunter.

1958. The sea trout or weakfishes (Genus Cynoscwn)
of the Gulf of Mexico. Gulf States Marine Fisheries
Comm., Technical Summary No. 1, 40 pp.
Gunter, Gordon.

1945. Studies on marine fishes of Texas. Publica-
tions of the Institute of Marine Sciences, vol. 1,
No. 1, pp. 190.
1950. Seasonal population changes and distributions
as related to salinity of certain invertebrates of the
Texas coast, including the commercial shrimp.
University Of Texas, Institute of Marine Science,

Publications vol. I, No. 2, pp. 7-51.

378

U.S. FISH AND WILDLIFE SERVICE

Gunter, Gordon, and J. Y. Christmas.

1960. A review of literature on menhaden with
special reference to the Gulf of Mexico menhaden,
Bnvoortia palronus Goode. U.S. Fish and Wildlife
Service, Special Scientific Report — Fisheries No.
363, 31 pp.

Kutkuhn, Joseph H.

1902. Recent trends in white shrimp stocks of the
northern Gulf. Proceedings of the Gulf and Carib-
bean Fisheries Institute, 14th Annual Session,
1901, pp. 3-16.

Moe, Martin A., Jr.

1963. A survey of offshore fishing in Florida. Florida
State Board of Conservation, Professional Papers
Series No. 4, 117 pp.

Odum, Eugene P.

1960. The role of tidal marshes and streams in
estuarine production. Minutes of the 19th Annual
Meeting of the Atlantic States Marine Fisheries
Commission, Appendix 6, 9 pp.

Pearson, John C.

1929. Natural history and conservation of the
redfish and other commercial sciaenids of the
Texas coast. U.S. Bureau of Fisheries, Bulletin,
vol. 44, pp. 129-214.

Power, E .A.

1960. Fishery statistics of the United States, 1958.
U.S. Fish and Wildlife Service, Statistical Digest
No. 49, 424 pp.

1961. Fishery statistics of the United States, 1959.
U.S. Fish and Wildlife Service, Statistical Digest
No. 51, 457 pp.

1962a Fisheries of the United States, 1961 (a pre-
liminary review). U.S. Fish and Wildlife Service-
Current Fishery Statistics No. 2900, 61 pp.

1962b. Fishery statistics of the United States, 1960.
U.S. Fish and Wildlife Service, Statistical Digest
No. 53, 529 pp.
Rathbun, Mary J.

1930. The cancroid crabs of America of the families
Euryalidae, Portunidae, Atelecyclidae, Cancridae
and Xanthidae. U.S. National Museum, Bulletin
152, pp. 99-111.

Reintjes, John W.

1961. Menhaden eggs and larvae from M/V Theo-
dore N. Gill cruises, south Atlantic coast of the
United States, 1953-54. U.S. Fish and Wildlife
Service, Special Scientific Report — Fisheries No.
393, 7 pp.

Rosen, Albert.

1959. Summary of Florida commercial marine land-
ings, 1959 and an analysis of the catch and effort of
certain species. The Marine Laboratory, Univer-
sity of Miami. Report to Florida State Board of
Conservation, 53 pp.

Rosen, Albert, and Robert W. Ellis.

1958. Summary of Florida marine fish landings for
1957. The Marine Laboratory, University of
Miami. Report to Florida State Board of Conser-
vation, 65 pp.

Rosen, Albert, and Richard K. Robinson.

1960. Summary of Florida commercial marine land-
ings, 1960 and an analysis of the catch and effort of
certain species. Institute of Marine Science, Uni-
versity of Miami. Report to Florida State Board
of Conservation, 32 pp.

Saloman, Carl H.

1964. The shrimp Trachypeneus similis in Tampa
Bay. Quarterly Journal Florida Academy of
Science, vol. 27, pp. 160-164.

1965. Bait shrimp Penaeus duorarum in Tampa Bay,
Florida — biology, fishery economics, and changing
habitat. U.S. Fish and Wildlife Service, Special
Scientific Report — Fisheries No. 520, 16 pp.

Saloman, Carl H., John H. Finucane, and John A.
Kelly, Jr.

1964. Hydrographic observations of Tampa Bay,
Florida, and adjacent waters, August 1961 through
December 1962. U.S. Fish and Wildlife Service,
Data Report No. 4, 6 microfiches, 114 pp.
Sandoz, Mildred, and Rosalie Rogers.

1944. The effect of environmental factors on hatch-
ery, moulting, and survival of zoea larvae of the
blue crab, Callinecles sapidus, Rathbun. Ecology,
vol. 25, No. 2, pp. 216-228.
Skdd, Bernard E., and W. B. Wilson.

1960. Role of estuarine waters in Gulf fisheries.
Transactions of the 25th North American Wildlife
Conference 1960, pp. 320-326.
Springer, Victor G., and Kenneth D. Woodburn.

1960. An ecological study of the fishes of the Tampa
Bay area. Florida State Board of Conservation,
Professional Papers Series No. 1, 104 pp.
Suttkus, R. D.

1958. Distribution of menhaden in the Gulf of
Mexico. Transactions of the 23d North American
Wildlife Conference, pp. 401-410.

Sykes, James E.

1964. Requirements of Gulf and south Atlantic
estuarine research. Proceedings of the Gulf and
Caribbean Fisheries Institute, 16th Annual Session,
1963, pp. 113-120.

1965. Multiple utilization of Gulf coast estuaries.
Proceedings of the 17th Annual Conference, South-
eastern Association of Game and Fish Commis-
sioners, 1963, pp. 323-326.

Tabb, Durbin C, and Raymond B. Manning.

1960. A checklist of the flora and fauna of northern
Florida Bay and adjacent brackish waters of the
Florida mainland collected during the period July,
1957 through September, 1960. Bulletin of Marine
Science of the Gulf and Caribbean, vol. 11, No. 4,
pp. 552-649.

Thompson, Seton H.

1961. What is happening to our estuaries? Trans-
actions of the 26th North American Wildlife
Conference, pp. 31S-322.

U.S. Fish and Wildlife Service.

1959. Gulf fisheries, 1958, annual summary. U.S.
Fish and Wildlife Service, Current Fishery Statistics
No. 2165, 12 pp.

IMMATURE SPECIES IN TAMPA BAY

379

GILL NET MESH SELECTION CURVES FOR PACIFIC SALMON ON THE

HIGH SEAS

By Alvin E. Peterson, Fishery Biologist (Research)
Bureau of Commercial Fisheries, Seattle, Wash.

ABSTRACT

Gill net mesh selection curves of normal distribution
were developed and applied to Pacific salmon caught by
research vessels on the high seas of the North Pacific
Ocean and the Bering Sea. Mesh selection curves were
constructed for pink, sockeye, and chum salmon for
each of four mesh sizes, 2y2-, 3Vi-> 41/2-> an<l 5V4-inch.

Catch efficiency curves for combined mesh sizes show
that the range for salmon lengths was covered, although
the coverage was not equal for all lengths. The length-
frequency distribution of each species was adjusted for
effect of gill net selectivity. Adjustments were minor.

The Bureau of Commercial Fisheries fishes
experimentally for salmon with surface gill nets on
the high seas of the North Pacific Ocean and the
Bering Sea. Salmon samples taken by gill nets
are used to estimate abundance, distribution, racial
identity, and growth of salmon populations in the
ocean. Accurate estimates of abundance, distri-
bution, racial identity, and growth require un-
biased samples from salmon populations in the
ocean. Gill nets are selective; a particular mesh
size of gill net selects a particular size range of fish.

To cover the range of fish sizes, four gill net
mesh sizes, 2K-, 3%-, 4%-, and 5%-inch, stretched
measure, of multifilament nylon twine are used
in the fishing. Selectivity studies are necessary
to assess the adequacy of this coverage and to
adjust the salmon size frequencies for any bias
caused by selectivity. Determining the shape
and extent of the mesh selection curve for each
mesh size and for combined mesh sizes is necessary
before size frequencies can be adjusted for possible
bias.

Note.— Approved for publication June 25, 1964.
FISHERY BULLETIN: VOLUME 65, NO. 2

A METHOD FOR DETERMINING GILL NET
SELECTIVITY

Holt (1957) described a method for determining
gill net mesh selection curves with normal fre-
quency distributions. He developed normal mesh
selection curves for Fraser River sockeye salmon
(from Peterson, 1954) and for North Sea herring
(from Hodgson, 1933). He used the ratio of
catches from adjacent pairs of mesh sizes at
different length classes to develop parameters for
the normal curve. The following formulations
were abstracted from Holt (1957) and McCombie
and Fry (1960):

CL=nPlpm-e-<*-W8'

(1)

where CL is the number of fish of length L caught,
n the number of operations or the fishing dura-
tion, PL the number of fish of length L liable to
capture, pm the fishing power of the mesh at the
mean selection length, e the base of natural
logarithms, Lm the mean selection length caught, and
S the standard deviation of distribution. The ratio
of catches for two meshes {A and B), differing
slightly in size and fishing together, can be de-

381

scribed by an equation of the linear form, y-
bL+a:

B(-L \B-L'm A^'mt'-L'

a Or.

T2 7"2

l'-1 m B1- n

2S2

-lOj

(2)

in which BCL is the catch of length L taken in

mesh B, BLm is the mean selection length of mesh B,

Bpm is the fishing power of mesh B, etc. The log

-jjP term will cancel; i.e., log 1=0, by assuming

A m

that the two nets have equal fishing power for
their respective mean lengths. If the terms from

, ■ /rt\ 11 bLz, B^m A^m ,

equation (2) are used, log -77=2/, ™ — =0

A*-L

(the slope), and

aL< n

2S2

'=a (the y intercept).

When equation (2) holds true, a plot of log ^-^

A^L

against various values of L gives a straight line,
and the assumption is justified that the mesh
selection curve is normal.

The selection curve parameters, ALm, BLm, and
S, are obtained as follows:

0/6=

aL„

- 7"2

m iB^-'rn AL^m

2S2
-2a/b=BLm+AL„

Lm aL>v

Assume that Lm is proportional to mesh size (0).
Assign a proportionality constant (K). Then,
ALm+BLm=—2alb = K{AQABQ), from which ALm
and BLm can be derived. S can be found from
either a or 6. With these values and a table of
ordinates for normal distribution (Snedecor, 1956),
mesh selection curves can be constructed.

APPLICATION OF METHOD TO SALMON
GILL NET CATCHES

I have applied the above analytical procedure to
length frequencies of three salmon species: pink,
sockeye, and chum. To illustrate the method, I
have used catch data for 1957 and 1959. In
these years the three species were well represented
in the gill net catches of the research vessels.
( latch data on sockeye and chum salmon for 1956,
1958, and 1960 were used in part of the analysis.
Table 1 shows the number of the three species
caught and measured during 1956 to 1960. The
cat dies were made during May to September on

the high seas of the North Pacific Ocean (north of
lat. 45° N.) and the Bering Sea.

PINK SALMON

Table 2 gives the length-frequency distributions
of pink salmon taken by the 3K-, 4&-, and 5%-
inch mesh gill nets in 1957. Table 3 gives similar
data for 1959. Catches were confined to three
mesh sizes; the 2%-inch mesh did not catch pink
salmon. Since more of the 4K-inch mesh than
of the 3%- and 5%-inch meshes was used in a
fishing set, catches of the 4%-inch mesh were re-
duced to equalize fishing effort. A 1:3 reduction
was necessary in 1957; a 1:6 reduction in 1959.
Length frequencies were grouped by 3-cm. length
classes. Fork length is related to mesh size.1

Tables 2 and 3 also give catch ratios of adjacent
mesh sizes, 4%/3}4-inch and 5K/4K-inch. The
catch ratio at each length class is limited to a
combined sample size of 50 or more fish for the
paired mesh sizes. By establishing a minimum
sample size of 50, I was able to omit smaller
samples that may not have been representative

Table 1. — Gill net catches of pink, sockeye, and chum salmon
by U.S. research vessels in the North Pacific Ocean and
the Bering Sea, 1956-60

Species '

Number of salmon caught and measured

1956

1957

1958

1959

1960

Pink_._

431
3,224
3, 565

3,129
3,584
4,678

174
1,177
3,744

4,202
fi. 462
6, 082

1,049

8,296

5,816

1 Coho and chinook salmon are excluded because of small catches.

Table 2. — Catch by mesh size and catch ratio of adjacent
mesh sizes, pink salmon, 1957

Fork length

Catch by mesh size '

Catch ratio

of length
class)

2M-inch

3M-inch

4H-irich

5}i-inch

log VAI
3J4-inch

log 5W

414-inch

Centimeters
35

Number

148

192

Number

363

300

109

1
13

-0.76

+.64

+2.00

+3. 51

-4.27

-3.32

-2. 24

-.84

1 Original catches of the 4'i-inch mesh were 3 times as large as shown: they
were divided by 3 to equalize lishing effort between mesh sizes.

i Mesh size as shown is factory-labeled size. During the 1060 fishing opera-
tions about 400 meshes (miii the fmir mesh sizes were measured. The average
measured size was either identical to the factory-labeled size or slightly
oversize.

::si'

U.S. FISH AND WILDLIFE SERVICE

Table 3. — Catch by mesh size and catch ratio of adjacent
mesh sizes, pink salmon, 1959

1957

1959

Fork length

Catch by mesh size '

Catch ratio

of length
class)

2J^-inch

3}i-mch

4H-inch

5H-inch

log *y2

3J4-inch

log 5Ji
4J^-inch

Centimeters

Number

Number
1
3
7
38
16
6
1
1
1

Number

26
201
236
135
46
14
3

-0.39
+2.53
+3.67
+4.90

6
14
51
49
30
3
3

-3.51

-2.83

-0.97

+0.07

i Original catches of the 4'i-inch mesh were 6 times as large as shown: they
were divided by 6 to equalize fishing effort between mesh sizes.

The natural logarithm of the catch ratio is
directly related to the length of pink salmon for
1957 and 1959 (fig. 1). The straight lines are
fitted by the least squares method. The relation
in both years is approximately linear. Holt
showed in equation (2) that this relation must
be linear if the mesh selection curve is normal.
With replicating evidence for 2 years, I feel justi-
fied in assuming that the mesh selection curve for
pink salmon is approximately normal.

To obtain the normal frequency curve for each
mesh size, the mean selection length and the
standard deviation of the curve were needed.
The estimation of these parameters for 1959 pink
salmon is shown in table 4 and the determination
of the normal curve in table 5.

A further step in applying the method was to
construct a composite selection curve from the
mesh selection curves of the three mesh sizes
(fig. 2). This composite curve was obtained by
summing at each length class the ordinate heights
of the individual curves (table 6), as was done by
McCombie and Fry (1960). The composite curve
can be called a "catch efficiency curve" because

Table 4. — Estimation of mean selection length and standard
deviation of mesh selection curves, pink salmon, 1959

Mesh sizes

Sum of
mesh sizes

Sum of mean
selection
lengths
(-2a/b)

Mean

selection

length

Standard

deviation of

selection

curve

3J4-inch (8.26cm.)...

Centimeters

Centimeters
34.8

Centimeters

31^ and 41-2-inch

4'X-inch (11.43 cm.).

19.69

81.36

4.9

48.1

24.77

105. 65

4.4

5K-inch (13.34 cm.)

56.2

22.23

93.50

+ 6r
+ 5
+ 4
+ 3

+ 2

» - I

4i"/3f

/ o = .47
/ b=-20.l

/5I74L"

/ 34 ' H 2

/ o = .38
/ b =-19.9

1 1 1 1 1

41 44 47 50 53
FORK LENGTH (CM]

41 44 47 50 53
FORK LENGTH (CM.)

Figure 1. — Catch ratio of adjacent mesh sizes by fork
length, pink salmon, 1957 and 1959.

Table 5. — Determination of ordinate heights of normal curve
for each mesh size, pink salmon, 1959

Fork length

3>£-inch mesh
L„=34.8, S=4.9 1

4M-mch mesh
L„=48.1, S = 4.6*

5J4-inch mesh
Lm=56.2, S = 4.4

of length
class)

L-L„

Ordinate
height

L-L„

Ordinate
height

L-L„

Ordinate
height

Centimeters
32

0.57
.04
.65
1.27
1.88
2.49
3.10
3.71

0.339
.399
.323
.178
.068
.018
.003

3.50

2.85

2.20

1 54

.89

.24

.41

1.07

1.72

2.37

3.02

0.001
.007
.036
.122
.268
.388
.367
.225
.091
.024
.004

38 -

4.23

3.55

2.77

2.09

1.41

.73

.05

.64

1.32

.001

.009

.045

.148

.306

56 .

.398

.325

.167

1 L„ = mean selection length (cm.), S = standard deviation (cm.).

2 Mean of 4.9 and 4.4.

Table 6. — Summation of ordinate heights of three mesh
selection curves, pink salmon, 1959

AT=93. 50/22.23 = 4. 21.

Ordinate height (by mesh size)

Sum of
ordinate

of length class)

3H-inch

4}i-inch

5!4-inch

heights

Centimeters
32

0.339
.399
.323
.178
.068
.018
.003

0.001
.007
.036
.122
.268
.388
.367
.225
.091
.024
.004

0.340

.406

.001
.009
.045
.148
.306
.398
.325
.167

.359

41 .._

.301

44 ___

.345

47...

.451

.518

53 ...

.531

.489

.349

.171

GILL NET MESH NET SELECTION CURVES FOR SALMON

383

1959

Catch efficiency curve

38 44 50

FORK LENGTH (CM.)

Figure 2. — Catch efficiency curve (sum of ordinate heights
at each length) for three mesh sizes combined, pink
salmon, 1957 and 1959.

it shows a relative catch efficiency of gill nets over
fish length range. Curves for 1957 and 1959 are
shown.

In both years the catch efficiency curves show
a dip at 41 cm. Catch efficiency at 41 cm. is lower
because of the 1%-inch gap between the 3%- and
4^-inch mesh sizes. The gap between the 4K- and
5^-inch meshes is % inch.

The final step in applying the method was to
reconstruct the length frequency curve of the
available fish population, adjusting for effect of
gill net selectivity. The uncorrected catch was
divided by the sum of ordinates at each length
class (table 7). The corrected catch for all length
classes was the length frequency curve adjusted
for effect of gill net selectivity.

When the uncorrected and the corrected length
frequency distributions of pink salmon taken by
combined mesh sizes of gill net in 1957 and 1959

Figure 3. — Length frequency distribution of pink salmon
adjusted for effect of gill net selectivity, 1957 and 1959.

are plotted, a single mode of maturing 2-year-old
fish is evident (fig. 3).

Adjustments for gill net selectivity in 1957 were
minor. In the uncorrected catches the 41-crn. and
44-cm. length classes were slightly under-repre-
sented and the 47-cm., 50-cm., and 53-cm. classes
were slightly over-represented. The corrected
catch curve adjusts for these conditions. The
mode, after I adjusted for selectivity, remains
unchanged at 44 cm.

In 1959 the amount of correction- was somewhat
greater than in 1957. As in 1957, the 41-cm.
and 44-cm. lengths were under-represented, the
47-cm., 50-cm., and 53-cm. lengths over-repre-
sented. Adjustments in 1959 changed the posi-
tion of the mode from 47 cm. to 44 cm.

SOCKEYE SALMON

Least squares lines were fitted to the catch
ratios of sockeye salmon taken in 1959 by the
four gill net mesh sizes (fig. 4). Catch data are
in table s. Catch ratios were computed for

384

U.S. FISH AND WILDLIFE SERVICE

Table 7. — Adjustment of 1959 catches of pink salmon
for effect of ail! net selectivity

Fork

length

(midpoint

of length

class)

Uncor-
rected

Sum ot
ordinate
heights

Corrected

Uncor-
rected

Corrected

Centimeter
32.

Number

223

266

187

0.340
.406
.359
.301
.345
.451
.518
.531
.489
.349
.171

Number

213

646

568

361

181

Percent

0.1

7.2

25.0

28.7

21.0

10.8

5.0

Percent

38 .

41...

44...

47...

8.6

4 3

59.

1 i

samples of 50 or more fish, as was done for pink
salmon. Sockeye salmon catch ratios for each
pair of mesh sizes showed approximate linearity
over the greater part of the range of fish lengths,
but not at the extremes of the range. Approxi-
mate linearity extended from 29 cm. to 38 cm.
for the 3}4/2}2-inch mesh sizes, from 38 cm. to
53 cm. for the 4}2/3K-inch mesh sizes, and from
47 cm. to 62 cm. for the 5^/4}o-inch mesh sizes.
Least squares lines were fitted in these ranges.
The procedure of discarding extremes in line-
fitting previously was used by Garrod (1961).

Figure 5 shows a similar picture for 1957
(data are in table 9). Catch ratios were ap-
proximately linear except at the extremes. In
1957 and 1959 similar length ranges were used
in line-fitting, except for extending the range to
41 cm. for the 3^/2K-inch mesh sizes in 1957.

38 44 50 56

FORK LENGTH (CM.)

Figure 4. — Catch ratio of adjacent mesh sizes by fork
length, sockeye salmon, 1959.

+ 6
+ 5

+ 4

o+3

< +2

5 +l

q -2

-3
-4

3i"/8i"

/ ~"~*

45V3V

• /

/ b = .63
/ o =-20.8 •

A'*

/ \

7 "*

/b = 42 /

/ */

• /^•">Lz

rv 2.

a =-11.7

•

/* *

/
/

1 1 1 1 1

FITTED LINE

EXTREMES

1 1 1 1 1 1 1

38 44 50 56

FORK LENGTH (CM)

Figure 5. — Catch ratio of adjacent mesh sizes by fork
length, sockeye salmon, 1957.

Table 8. — Catch by mesh size and catch ratio of adjacent
mesh sizes, sockeye salmon, 1959

Fork
length

Catch of sockeye by mesh size '

Catch ratio

(midpoint

of length

class)

2}- 2-inch

3!4-mch

4>2-inch

5K-inch

log V/tl

L" --inch

log IHI
3K-inch

iog5HI
4H-mch

Centimeters
26

Number
9
88
293
279
22

1
6
1
3

Number

3
139

648
268
34
41
44
16
9
9
9
6
4

-3.38
-.76
+.85

+2.50

111

161

155

118

7
2

(-3. 54)

(-4.27)

-3.96

-2.85

-.58

+.92

+2.40

+2.84

(+2. 94)

(+1.88)

35...

38...

41...

144

116

(+1. 99)

-2.76

50....

-1.94

63.

-.47

+.19

+.68

62...

+.82

65....

2
1

74....

1 Original catches of the 4££-inch mesh were 6 times as large as shown;
they were divided by 6 to equalize fishing effort between mesh sizes.

Note. — Catch ratios in parentheses were not used. See text.

Catch ratios showing the linear relation represent
mainly fish which were enmeshed (gilled) around
the head and gill cover by the net twine. Catch
ratios departing from the straight line at either
end were discarded because they represent large
fish snagged or small fish tangled in the gill nets.

In the 1959 sockeye catch ratios of the 4>2/3^-
inch mesh sizes (fig. 4), the discarded catch ratios
at 32 cm. and 35 cm. and at 56 cm. and 59 cm.
curve away from the fitted line, giving the effect
of a tipped S-shaped curve. At 32 cm. and 35 cm.
the fish in the 4}£-inch mesh were probably

GILL NET MESH NET SELECTION CURVES FOR SALMON
774-711 0—66 7

385

Table 9. — Catch by mesh size and catch ratio of adjacent
mesh sizes, sockeye salmon, 1957

Fork

Catch of sockeye by mesh size '

Catch ratio

(midpoint

of length

class)

2V2-inch

3Ji-inch

4H-mch

5K-inch

log toil
2! 4-inch

log VAI
3J4-mch

log5M/
4' £- inch

Centimeters
23

Number

168

176

108

-2.90
-.62
+ 1.66
+3.09
+4.68

1
2

133

194

146

108

1
1
1

11
50
100
121
114
54
20
1
1

(-4.62)
-3.77
-2.60
-.40
+.85
+1.74
+2. 28
(+2.48)
(+1.44)

47...

3
4
3
3
2

(+4. 04)

-2.49

-1.36

-.38

+.11

+.31

+.73

1 Original catches of the 4H-inch mesh were 3 times as large as shown;
they were divided by 3 to equalize fishing effort between mesh sizes.

Note. — Catch ratios in parentheses were not used. See text.

tangled rather than gilled. At 56 cm. and 59 cm.
the fish in the 3%-inch mesh were mainly snagged
rather than gilled. Some fish within the 38-cm.
to 53-cm. length range also were snagged or
tangled, but the numbers were so small that
the linear relation between fish length and log of
catch ratio was unaffected.

The procedure for developing mesh selection
curves and a catch efficiency curve for sockeye

1959

- UNCORRECTED CATCH
CORRECTED CATCH

38 44 50 56

FORK LENGTH (CM)

Figure 6. — Length frequency distributions of sockeye
salmon adjusted for effect of gill net selectivity, 1957
and 1959.

salmon followed that for pink salmon. Table 10
shows the summation of the ordinate heights of
the mesh selection curves for the four mesh sizes.
The composite curve was used to adjust for
selectivity effect (table 11).

A comparison of the uncorrected and corrected
length frequency distributions of sockeye salmon
in 1957 and 1959 shows that the 44-cm. and 47-cm.
fish are under-represented, the 53-cm. to 59-cm.
over-represented in the uncorrected catches (fig. 6).
Over most of the length range, adjustments were
quite minor.

Adjustments for the effect of gill net selectivity
changed slightly the shape of the length-frequency
distribution curve of sockeye salmon. The
length-frequency distributions in 1957 and 1959
were bimodal. Mode 1 consisted of small fish
(highly abundant in 1959) that had spent one
winter at sea. Mode 2 consisted of large fish that

Table 10. — Summation of ordinate heights of four mesh
selection curves, sockeye salmon, 1959

Fork length (midpoint

Ordinate height (by mesh size)

Sum of

of length class)

2H-inch

3J<-inch

4J^-inch

5J4-inch

ordinate
heights

Cm.
26 _

0.268
.398
.306
.122
.025
.003

0.013
.056
.165
.319
.391
.327
.176
.062
.014
.002

0.281

.454

0
.003
.014
.049
.124
.242
.357
.398
.337
.216
.106
.039
.011

.471

.444

0
.001
.005
.019
.060
.142
.259
.365
.398
.335
.218

.430

.380

.305

.323

50 ..

.431

.542

.596

59 _

.'581

62...

.504

.374

.229

Table 11. — Adjustment of the 1959 catches of sockeye salmon
for effect of gill net selectivity

Fork length

(midpoint

of length

class)

Un-
corrected

Sum of
ordinate
heights

Corrected

Un-
corrected

Corrected

Centimeter
26

Number

440

943

297

168

201

264

271

187

0.281
.454
.471
.444
.430
.380
.305
.323
.431
. 642
.596
.581
.504
.374
.229

(. 044)

Number
32
201
944
2,158
678
97
218
525
472
491
455
321
156
85
30

Percent
0.3
2.9
14.2
30.5
9.6
1.2
2.2
5.4
6.5
8.5
8.8
6.0
2.6
1.0
.2

Percent
0.5

2.9

13.8

31.4

9.9

1.4

3.2

7.6

50..

6.9

7.2

56 ..

6.6

4.7

62 _-

2.3

1.2

68 -

Note.— Length class 74 cm. was omitted.

:;st)

U.S. FISH AND WILDLIFE SERVICE

Table 12. — Catch by mesh size and catch ratio of adjacent
mesh sizes, chum salmon, 1967

38 44 50 56

FORK LENGTH (CM.)

7. — Catch ratio of adjacent mesh sizes by fork
length, chum salmon, 1957.

38 44 50 56

FORK LENGTH (CM.)

Figure 8. — Catch ratios of adjacent mesh sizes by fork
length, chum salmon, 1959.

had spent mainly two and three winters at sea.
Mode 1 did not change position, but mode 2
shifted to smaller fish when adjusted for selec-
tivity. This change occurred in both years.

Chum salmon

The problems encountered for chum salmon and
the results obtained are almost identical to those
for sockeye salmon. As with sockeye, chum
salmon catch ratios of a minimum 50-fish sample

Fork
length

Catch of chum by mesh size '

Catch ratio

(mid-
point of
length

class)

VAr

inch

3H-
inch

inch

5M-

inch

log 3H/
2^-inch

log i'AI
3M-inch

log 5H/
4.H-incn

Centi-
meters
26

Num-
ber
5
330
523
52
8
2
3
3
3

Num-
ber

2
28
89
78
109
119
100
58
13
6
4

8
52
191

285

203

117

105

-5.12
-2.92
+.54
+2.28
+4.00
(+3. 68)
(+3. 50)
(+2. 96)

-0.83
+.65
+1.59
+2.75
(+2.97)
(+2.44)

(-3.27)
-2.21
-1.49
-.66
-.01

+.36

+.94

' Original catches of the 4^-inch mesh were 3 times as large as shown; they
were divided by 3 to equalize fishing effort between mesh sizes.

Note. — Catch ratios in parentheses were not used. See text.

Table 13.

-Catch by mesh size and catch ratio of adjacent
mesh size, chum salmon, 1969

Fork

Catch of chum by mesh size '

Catch ratio

(mid-
point of
length

class)

1>A-
inch

3M-

inch

VA-
inch

5M-
inch

log 3M/
2^-inch

log mi
3 M -inch

log 5H/
4J-£-inch

Centi-
meters
29

Num-
ber
9
57
18
3
2
4
1
1
2

Num-
ber

11
44
93

156
196
84
37
5
2

160

232

195

113

2
8
14
67
116
95
45
24
4
2

-1.64

+ .89
+3.42
+4.36
(+3. 89)
(+4. 43)

-3.65
-1.41
+.53
+1.78
+3.66
(+4.03)

(-3.22)
-3.00
-2. 81

-1.08

+.03

+.50

+1.17

' Original catches of the 4W-inch mesh were 6 times as large as shown; they
were divided by 6 to equalize Ashing effort between mesh sizes.

Note. — Catch ratios in parentheses were not used. See text.

for each pair of mesh sizes were approximately
linear over a greater part of the range of fish
lengths but not at the extremes. The length
ranges for chum salmon were identical to those
established for sockeye. Least squares lines were
fitted to the 1957 and 1959 catch ratios of the
three pairs of mesh sizes (figs. 7 and 8). Catches
on which these lines were based are given in tables
12 and 13. Table 14 sums up the ordinate heights
for the four mesh sizes.

Figure 9 and table 15 show the uncorrected and
corrected length-frequency distributions of chum

GILL NET MESH NET SELECTION CURVES FOR SALMON

387

Table 14. — Summation of ordinate heights of four tnesh
selection curves, chum salmon, 1959

Fork length (midpoint

Ordinate height (by mesr

size)

Sum of
ordinate

of length class)

2'-2-inch

3J4-inch

4H-inch

5K-inch

heights

Cm.
26

0.242
.393
.319
.130
.026
.003

0.006
.033
.122
.280
.395
.341
.180
.060
.012
.001

0.248

29 -

.426

.001
.005
.024
.078
.187
.323
.398
.352
.223
.102
.033
.008

.441

.411

.426

.001
.007
.030
.091
.201
.331
.398
.352
.228

.368

.259

.254

.365

.490

56 - -_

.553

.554

62 ..

.500

65 .-

.385

68...

.236

salmon. In 1957 and 1959 the corrected catches
increased at 44 cm. and 47 cm. and decreased at
53 cm. to 59 cm. As with sockeye, the mode of
the large chum salmon shifted to smaller fish when
adjusted for selectivity.

SELECTIVITY COMPARED FOR THE
THREE SPECIES

The catch efficiency of the combined mesh sizes
was compared for pink, sockeye, and chum salmon
(fig. 10). Curves were given for sockeye and chum
salmon ranging in length from 29 cm. to 62 cm.
and for pink salmon from 38 cm. to 56 cm.; these
covered 98 percent of the samples. Chum and
sockeye curves are similar and show a dip in catch
efficiencv at 44 cm. and 47 cm., resulting from the

38 44 50 56

FORK LENGTH (CM.)

38 44 50 56

FORK LENGTH (CM)

Figure 10. — Comparison of catch efficiency of combined
mesh sizes on pink, sockeye, and chum salmon, 1957 and
1959.

Table 15. — Adjustment of the 1959 catches of chum salmon
for effect of gill net selectivity

Fork length (mid-
point of length class)

Uncor-
rected

Sum of
ordinate
heights

Corrected

Uncor-
rected

Corrected

Centimeters
29

Number

162

250

253

284

269

231

154

(2)

0.426
.441
.411
.426
.368
.259
.254
.365
.490
.553
.554
.500
.385
.236

(. 176)

Nu mber

156

153

228

440

965

996

778

549

418

278

122

Percent

0.5

3.6

3.3

5.0

8.4

12.9

13.1

14.7

13.9

11.9

8.0

3.2

1.4

Percent
0.4

3.0

2.9

38...

4.4

8.5

18.6

19.2

50...

15.0

56 .

10.6
8.0

5.4

65-.

2.3
1.4
.3

Figure 9. — Length frequency distribution of chum salmon
adjusted for effect of Rill net selectivity, 1957 and 1959.

Note.— Length class 71 cm. was omitted.

lK-inch gap between the Zy4- and 4^-inch mesh
sizes. Both curves show peak catch efficiency at
56 cm. and 59 cm. The mode for sockeye is about
56 cm., for chum about 57 cm. The pink salmon
curve shows peak catch efficiency at 53 cm. and
lowest catch efficiency at 41 cm.

388

U.S. FISH AND WILDLIFE SERVICE

The shape of the catch efficiency curves for
sockeye and chum salmon between 44 cm. and
62 cm. and for pink salmon between 38 cm. and
56 cm. is somewhat similar. The pink salmon
curve is displaced to shorter fish. Pink salmon
probably have greater girth per given length than
the other two species, although no girth measure-
ments of pink salmon were taken to verify this.
Differences shown in figure 10 probably
result from girth/length differences among the
three species.

DISCUSSION

Certain assumptions in applying Holt's method
were considered. One assumption was that stand-
ard deviations of selection curves should be similar.
A computation of the S values for each year from
1956 to 1960 checked this assumption. Table 16
lists jS values for each pair of mesh sizes. Sockeye
and chum salmon S" values are given for all years.
Pink salmon S values were computed only for odd-
numbered years; catches were small in even-
numbered years.

Standard deviations of selection curves within
each species were reasonably similar in at least, the
larger mesh sizes, 3)1-, 4%-, and 5%-inch. Pink
salmon had slightly higher S values and sockeye
slightly lower S values in the paired 3%- and 4^-
inch mesh sizes than in the4&- and 5}4-inch (table
16). Chum salmon also varied only slightly be-
tween these sizes. In the 2%- and 3%-inch pair
of mesh sizes, however, the S values for sockeye
and chum salmon were low. The small 2%-inch
mesh was probably the main cause of these low
values.

Table 16. — Standard deviation of mesh selection curves for
pink, sockeye, and chum salmon by year

Salmon species

Year

Standard deviation (paired mesh
sizes)

2H-ineh

and
3J4-inch

3Ji-inch

and
4J4-inch

4J/2-inch

and
534-inch

Pink

1957
1959
1956
1957
1958
1959
1960
1956
1957
1958
1959
I960

Centi-
meters

Centi-
meters
5.4
4.9
5.5
5.9
5.1
5.5
5.4
5.6
5.6
4.4
5.0
5.2

Centi-
meters

4.6

4.4

3.5

3.7
3.1
3.9
4.0
3.6
3.4
3.7
3.6
3.8

6. 1

Do....

6.5

Do..

Do....

5.9

Do....

6.3

5.3

Do...

6.5

5.5

Do..

5 4

Do..

5 1

Another assumption was that the mean selection
length of salmon is proportional to mesh size.
Mesh size (perimeter) is directly related to the
fish's girth. Lander (1963) showed that the
girth and length of sockeye and chum salmon of
the high seas have a linear relation. Thus, the
relation of length of salmon and mesh size war-
rants using proportionality constants (K values).

K values within species varied remarkably
little annually (table 17). Between species, K
values for pink salmon were lower than those for
sockeye and chum salmon, probably because
pink salmon have greater girth per given length.
As shown in table 17, mean selection lengths had
lower values in pink salmon than in the other two
species.

All investigators did not use normal distribu-
tion for the mesh selection curve. Some used
a skewed mesh selection curve, tailing off to the
right, rather than a normal curve. Olsen (1959),
working with Newfoundland herring data, found
that logs of catch ratios followed a parabolic
line better than a straight line. His selection
curves, thus, are slightly skewed rather than
normal. Ishida (1962) used a mesh-size ratio
method in developing skewed selectivity curves
for salmon from the North Pacific. Gulland and
Harding (1961), using gill net catches of the
African catfish Clarias, obtained a skewed selection
curve with a long upper tail. The shape of
Clarias (long fish with a large bony head) and
the method of its capture (entanglement in

Table 17. — Proportionality constants and mean selection
lengths for pink, sockeye, and chum salmon

Year

Mean selection length by mesh size

species

2K-inch
6.35 cm.

3i£-mch
8.26 em.

452-inch
11.43 cm.

5!4-inch
13.34 cm.

Pink

1957
1959

1956
1957
1958
1959
1960

4.28

4.21..

Mean

4.53.

4.49

4.62

4.60

Mean

4.63

4.68

4.67

4.73

Mean

cm.
27.2
26.7

em.
35.4
34.8

cm.
48.9
48.1

cm.
57.1
56.2

27.0

35.1

48.5

56.6

Sockeye . ..

28.8
29.3
28.5
29.3
29.2

37.4
38.2
37.1
38.2
38.0

51.8
52.8
51.3
52.8
52.6

611 1
61.6
59.9
61.6
61.4

29.0

37.8

52.3

61.0

Chum

29.4
29.7
29.7
29.7
30.0

38.2
38.7
38.7
38.6
39.1

52.9
53.5
53.5
53.4
54.1

61.8
62.4
62.4
62.3
63.1

29.7

38.7

53.5

62.4

i if= Proportionality constant of fish length divided by mesh size.

GILL NET MESH NET SELECTION CURVES FOR SALMON

3S9

several meshes) are thought to cause the
asymmetry.

Other investigators besides Holt used normal
distribution for mesh selection curves. McCombie
and Fry (1960), working with Lake Huron white-
fish data, concluded that normal distribution best
describes the mesh selection curve. Using nylon
gill net catches of Tilapia from Lake Victoria, East
Africa, Garrod (1961) showed that normal dis-
tribution applies over most of the selection range of
fish lengths but not at the extremes of this range.
Garrod used the normal curve obtained from
linear regression after discarding tlio extremes
where the relation departs from linear. I also used
the procedure of discarding the extremes and then
applying the normal curve.

SUMMARY

1. A method for determining gill net selectivity
described by Holt (1957) was applied to experi-
mental gill net catches of pink, sockeye, and chum
salmon from the high seas of the North Pacific
Ocean and Bering Sea. This method develops
mesh selection curves for gill nets of different mesh
sizes from catch ratios at various fish lengths.

2. A normal mesh selection curve, representing
relative catch efficiency of the mesh for different
length classes of fish, was constructed for each
mesh size, 2%-, 3%-, 4%- and 5M-inch, for each
species. Normal distribution can be used validly
when extreme sizes of fish caught by snagging and
tangling rather than gilling are omitted.

3. A composite curve of relative catch effi-
ciencies for combined mesh sizes shows that the
four mesh sizes cover the range of salmon lengths.
AH, length classes were not caught with equal
efficiency. A lower catch efficiency at 44 cm. of
47 cm. for sockeye and chum salmon and 41 cm. for
pink salmon, resulted from the larger (1%-inch)
gap between the 3%- and 4}2-inch mesh sizes. The
gap between other adjacent mesh sizes was three-
quarter inch.

4. The composite curve for each species was used
to adjust gill net catches for selectivity effect.
Adjustments were minor.

ACKNOWLEDGM ENTS

R. H. Lander helped with the mesh selection
theory, F. C. Cleaver made suggestions for writing
the report, and W. F. Royce reviewed the report.

LITERATURE CITED

Garrod, D. J.

1961. The selection characteristics of nylon gill nets
for Tilapia esculenta Graham. Journal du Conseil,
vol. 26, No. 2, pp. 191-203.

GULLAND, J. A., AND D. HARDING.

1961. The selection of Clarias mossambicus (Peters)
by nylon gill nets. Journal du Conseil, vol. 26,
No. 2, pp. 215-222.

Hodgson, William C.

1933. Further experiments on the selective action of
commercial drift nets. Journal du Conseil, vol. 8.
No. 3, pp. 344-354.

Holt, S. J.

1957. A method of determining gear selectivity and
its application. ICNAF-ICES-FAO Joint Scien-
tific Meeting, Lisbon, Paper No. S15, 21 pp.
[Mimeographed.)

Ishida, Teruo.

1962. On the gill net mesh selectivity curve. Hok-
kaido Regional Fisheries Research Laboratory,
Bulletin No. 25, pp. 20-25. [In Japanese with
English summary.]

Lander, Robert H.

1963. Girth-length relationships in sockeye and chum
salmon. Transactions of the American Fisheries
Society, vol. 92, No. 3, pp. 305-307.

McCombie, A. M., and F. E. J. Fry.

1960. Selectivity of gill nets for lake whitefish,
Coregonus clupeaformis. Transactions of the Ameri-
can Fisheries Society, vol. 89, No. 2, pp. 176-184.
Olsen, Steinar.

1959. Mesh selection in herring gill nets. Journal of
the Fisheries Research Board of Canada, vol. 16,
No. 3, pp. 339-349.
Peterson, A. E.

1954. The selective action of gill nets on Fraser River
sockeye salmon. International Pacific Salmon
Fisheries Commission, Bulletin No. 5, 101 pp.
Snedecor, George W.

1956. Statistical methods applied to experiments in
agriculture and biology. The Iowa State Uni-
versity Press, Ames, Iowa, 534 pp.

390

1 .S. I ISIl \\I> WILDLIFE SERVICE

LIFE HISTORY OF THE GIZZARD SHAD, DOROSOMA CEPEDIANUM (LE

SUEUR), IN WESTERN LAKE ERIE

By Anthony Bodola, Conservation Fellow1
The Franz Theodore Stone Institute of Hydrobiology of the Ohio State University, Put-in-Bay, Ohio

ABSTRACT

The rapid increase in the stocks of gizzard shad in
Lake Erie since 1950 unquestionably had an important
effect on the ecology of the lake. The present study,
based on almost 24,000 fish collected by various means
in 1952-55 in or near the island area of western Lake
Erie was undertaken to provide information on the
role of shad in the bionomics of the region.

The annulus of the gizzard shad scale is a valid year-
mark. It is laid down in May-July, a little later in the
older than in the younger fish. The body-scale relation
is linear with an intercept of 22.1 mm. on the axis of
standard length. Age-groups 0, I, and II were abun-
dantly represented in the samples. Age-group III was
was much less well represented, and older fish were
extremely scarce. The oldest shad seen belonged to
the \T-group.

The seasonal growth was most rapid in July-August
and growth was much reduced or nil in January-April.
Males attained the following average standard lengths
(in millimeters) at the end of the indicated years of life:
1-141; 2-273; 3-313; 4-343; 5-349. For females these
values were: 1-140; 2-285; 3-335; 4-364; 5-386.

The weight of the gizzard shad increased as the 3.07053
power of the length. The length-weight relation varied
seasonally, annually, and, near the spawning season,
according to sex and state of gonads.

Although the gizzard shad is distributed widely
throughout the Mississippi Valley and in stream sys-

tems tributary to the Gulf of Mexico and the Atlantic
Coast north to about lat. 40° N., some question exists
as to whether it is native to the Great Lakes-St. Law-
rence basin or has penetrated into this region in historic
times. Gerking (1945) was of the opinion that this fish
migrated from the Mississippi drainage into the glacial
Great Lakes during the Lake Maumee outlet stage.
Kirtland (1850) believed that it gained access to Lake
Erie from the Mississippi drainage recently by way of
various Ohio canal connections. Trautman (1957), on
the other hand, thinks that the gizzard shad was present
in Lake Erie waters before the advent of the canals.
Miller (1957) believed the question of whether the shad is
native to Lake Erie cannot be solved conclusively.

The establishment of gizzard shad in Lake Erie in
large numbers appears to have taken place fairly
recently, however, and their presence in Lakes Huron,
Michigan, and Ontario became known subsequent to
collections of the species along the south shore of Lake
Erie. The report of gizzard shad in the St. Lawrence
River at Quebec is of recent date. Fresh-water fishery
investigations — especially of rough fish — were so meager
prior to 1850 that shad could easily have been overlooked.

In the Great Lakes-St. Lawrence drainage the gizzard
shad has been reported from Lake Michigan in the west
to Quebec in the east, but it has become best established
along the western and southern shores of Lake Erie and
in streams tributary to these shores.

The role of the gizzard shad in the ecology of
fish populations is difficult to assess. Its value
as a link in the food chain is not to be questioned.
On the other hand, no use for shad other than as

Note.— Approved for publication August 13. 1964.

1 Present address: U.S. Bureau of Sport Fisheries and Wildlife, Cooperativ
Unit, Pennsylvania State University. University Park, Pa.

forage fish has been developed and their rapid
growth soon makes them too large for most pred-
atory fish. Shad tend to overpopulate many
waters to a degree that seems to be detrimental
to other species. In some southern states re-
duction of numbers of shad is part of the fish-
management program for certain waters.

FISHERY BULLETIN: VOLUME 65, NO. 2

391

In the past years, the numbers of gizzard shad
in Lake Erie were too few for the species to create
any important problems, indeed, to have any real
significance in the bionomics of the lake, but
recently their abundance has increased enor-
mously. Mass mortalities have created esthetic
and public-health problems, water intakes have
been plugged, and commercial fishermen have
wasted hours sorting and discarding the worth-
less shad from their catches. From the fish-
management standpoint, the question arises
whether the value of shad as forage may not now
be outweighed by their diversion of the productive
capacity of the lake into commercially valueless
fish. An inquiry into the natural history of the
gizzard shad in Lake Erie, accordingly, has been
much needed.

Only a few precocious male and female gizzard
shad attain sexual maturity as age group I.
Almost all males and a good percentage of females
mature at age II and only rarely are Ill-group
shad immature. Development of the egg and
seasonal changes of the ovary are described.
Egg production is highest in the II group —
average of 378,990 per individual and 689 per
gram of body weight. Spawning takes place from
early June into July and is most intensive near
mid-June. Heaviest spawning is at water tem-
peratures of 67° F. or more. Early development,
to the attainment of the adult shape is described;
particular attention is given to the development
of the alimentary tract.

The anatomy of the digestive tract in the adult
is described and comments are offered on the
function of such organs as the pharyngeal pouches
and the caeca. Tests were made for digestive
enzymes in different parts of the tract. The
gizzard shad is a filter feeder. Food varies
widely with season and locality but consists
mostly of phytoplankton and zooplankton.

The gizzard shad population has been increasing
in Lake Erie. Commercial fishermen told me that
3 decades ago the "sawbelly" was something of a
rarity — only an occasional one was caught. They
have attained greatest abundance, according to
these fishermen, since about 1950. Whether this
increase results from adaptations to the Lake Erie
environment, to changes in the character of the
lake, or merely to increasing surpluses of shad
beyond environmental and predatory inroads has
not hecn determined.

Gizzard shad seem to be most plentiful in the
shallow waters around the periphery of western
Lake Erie, in the Bass Islands area, and especially
in protected bays and mouths of tributaries.
The numbers present here vary from season to
season. They are most numerous in late summer
and early fall when their abundance is increased
by the recruitment of the young of the year.
They are next most plentiful just prior to and
during their spawning season in late spring when
the mature shad congregate in the shallow waters.
Then, too, in winter they concentrate in places
into which warm streams flow. At other times
they are rarely seen in numbers — frequently days
go by without any captures of shad by the com-
mercial fishermen of South Bass Island.

The tendency of shad to inhabit shallow water,
their attraction in massive numbers to the warmer
water of outlets from industrial plants and of
inflowing streams, and the frequent mass mortal-
ities doubtless have given rise to an exaggerated
idea of their abundance. Nevertheless, they are
plentiful and their numbers are growing. The
shad problem is real in both a practical and a
purely scientific sense.

MATERIALS AND METHODS

The investigation of the fife history of the
gizzard shad was based on almost 24,000 fish
(about two-thirds of which were young of the
year) captured in western Lake Erie and in streams
tributary to the southwestern shore of this lake
in 1952-55. Studies of age, length, weig'ht,
growth, reproduction, and fecundity were made
for shad captured in the lake. Fish caught in
Sandusky Bay and in the tributary streams were
omitted from those phases of the study because
of differences in growth and other aspects of their
life history.

The Sandusky Bay specimens were decidedly
smaller than lake fish of the same age and appeared
to have formed their annuli earlier in the year.
Also, they probably spawned earlier than the lake-
dwelling gizzard shad. The water in Sandusky
Bay was frequently turbid — the shallow water is
readily turned over by winds. Phytoplankton,
though reduced by this turbidity, is not lacking,
for much is washed into the bay from the marshes
by the tributary streams. Stomach contents of
fish caught in Sandusky Bay were largely muddy.
The slower growth of the fish here probably

.'I'.iJ

U.S. FISH AND WILDLIFE SERVICE

Statute Miles

Figure 1. — Western Lake Erie where gizzard shad were collected in 1952-55.

resulted from the reduced nutriment. The earlier
annulus formation and spawning are undoubtedly
related to the earlier warming of the shallow
waters in the bay.

The gizzard shad caught in the streams were
not as deep-bodied as either the lake or the
Sandusky Bay fish; and they were smaller, age
for age, than those captured in Sandusky Bay.
They were thinner, more gracefully shaped indi-
viduals, seemingly better adapted for swimming
in streams. Probably the colder water and the
poorer food supply were responsible for their
slower growth.

Methods, Dates, and Sites of Collection

With the exception of gizzard shad from San-
dusky Bay or tributary streams and a few otter
trawl collections in the open lake, all samples were
captured in western Lake Erie within one-half of a
mile of island or mainland shores (fig. 1).

Gizzard shad were captured in the deeper water
by 5-inch mesh (stretched measure) gill nets and

standard commercial trap nets. Closer to shore,
in 4 to 10 feet of water, I collected them by means
of 4-inch mesh gill nets, experimental gill nets with
meshes ranging from 1 to 4 inches, dynamite,
rotenone, and electric shocks. In waters less than
4 feet deep, along the shore, I used "Common
Sense" seines, a push seine, bag seine, and dip net.
In Sandusky Bay the fishermen employed haul
seines. See table 1 for methods of collection for
each month and year and table 2 for methods of
collection for each locality.

Data Recorded for Individual Fish

All fish lengths in this paper are standard
lengths, in millimeters. Lengths of small fish were
determined with the aid of a pair of dividers.
Larger fish were measured on a measuring board.
Most of the measurements were taken shortly
after the fish were caught. When the sample was
large, some of the fish were kept temporarily (1 to
2 days) in 10 percent formalin. Preservation in
formalin for a week resulted in no perceptible

GIZZARD SHAD IN WESTERN LAKE ERIE

393

Table 1.- — Number of gizzard shad collected in 1962-56 by methods, year, and month
[Number of samples in parentheses]

Method of collection

Year and month

Small-
mesh
seine1

Haul
seine

Picked
up dead

Experi-
mental
gill net

4- or 5-inch

mesh gill

net

Commer-
cial trap
net

Otter

trawl

Dynamite

Rotenonc

Electric
shocking

Total

1952:
July

125 (5)
27 (3)
9 (2)
1 (1)
183 (7)
92 (6)

24 (3)

125 (5)

247 (1)

274 (4)

Sept

17 (2)

26 (4)

Oct

1 (1)

77 (1)

260 (8)

390 (2)
7 (1)

482 (8)

1953:

31 (4)

Feb

27 (5)
2 (1)

27 (5)

2 (1)

1 (1)

324 (17)
129 (6)

325 (18)

115 (1)

158 (2)
64 (3)

34 (4)

244 (7)

81 (3)

1,456 (11)

836 (10)

26 (2)

4 (1)

239 (5)

July

1, 520 (14)

543 (2)

67 (3)

1, 480 (19)

1, 195 (6)
725 (10)

1, 762 (9)
403 (1)

1, 221 (8)

Oct

158 (2)

897 (13)

13 (4)

21 (6)

46 (9)
242 (16)
20 (7)
29 (8)
18 (7)
427 (21)
227 (8)
120 (7)

1,775 (13)

Dec

2 (1)

426 (8)

109 (10)
286 (17)
20 (7)
68 (16)
81 (18)

1954:

63 (1)
44 (1)

Feb

39 (8)
63 (11)
713 (14)
540 (16)
77 (2)

268 (2)
143 (9)

1. 408 (37)

1, 560 (35)

8,662 (15)

876 (1)

132 (1)

July

650 (2)
943 (2)

94 (2)

7,428 (2)
876 (1)

Sept

Oct

132 (1)

Dec . .—

1955:

3 (1)
19 (8)

2 (1)
161 (5)

6 (3)
459 (44)

3 (1)

Feb

19 (8)
4 (2)

2 (1)

148 (9)
204 (12)
284 (6)

309 (14)

210 (15)

743 (50)

Total

3,275 (65)

371 (10)

136 (8)

927 (7)

2,061 (157)

6,702 (131)

399 (4)

8,304 (3)

1,593 (4)

67 (3)

23,835 (392)

1 Of various types mentioned in text.

Table 2. — Gizzard shad collected in 1952-55 by method and locality
[Number of samples in parentheses]

Method of collection

Locality

Small-
mesh
seine1

Haul
seine

Picked
up dead

Experi-
mental
gill net

4- or 5- inch -

mesh gill

net

Commer-
cial trap
net

Otter
trawl

Dynamite

Rotenone

Electric
shocking

Total

Fishery Bay (South Bass

2,350 (38)

27 (1)
76 (4)

116 (7)
233 (4)

28 (2)
218 (2)

46 (1)
74 (1)
26 (1)
44 (1)
10 (1)

126 (7)

927 (7)

1,558 (134)
316 (21)

8,304 (3)

1,593 (4)

67 (3)

14,925 (196)

Bass Islands, Ohio

6,702 (131)

399 (4)

7,444 (157)

Sanduskv Bay, Ohio

371 (10)

447 (14)

116 (7)

233 (4)

28 (2)

218 (2)

46 (1)

East Harbor. Ohio

74 (1)

Colchester, Ontario

26 (1)

44 (1)

10 (1)

187 (2)

4 (1)
23 (1)

4 (1)

23 (1)

10 (1)

Total

3,275 (65)

371 (10)

136 (8)

927 (7)

2,061 (157)

6,702 (131)

399 (4)

8,304 (3)

1,593 (4)

67 (3)

■j:<. s:</> i:«rji

1 Of various types mentioned in text.

394

U.S. FISH AND WILDLIFE SERVICE

change in length; and the loss in weight was about
1 percent.

The relation of total length to standard length
was obtained by fitting a line by means of least
squares to the length measurements. The regres-
sion equation was £,=4.9 + 1.23 Ls, where L, is
total length and Ls is standard length.

For the determination of age, three or more
scales were removed from every gizzard shad
longer than 100 mm. Among the smaller shad,
scales were taken from random samples of fish
from each collection. The scales were placed on a
glass slide immediately after removal from the
fish, and their annuli counted with the aid of a
dissecting microscope. The ages assigned were in
terms of the number of annuli. Since the age
designation changes on January 1, a fish captured
between this date and the actual time of annulus
formation was credited with a "virtual annulus"
at the edge of the scale (Hile, 1948).

The scales employed in the study of the body-
scale relation and for the calculation of growth
were removed from a "key area." Since gizzard
shad lose their scales readily, a "key scale" fre-
quently would have been missing or regenerated.
Use of a key area eliminated discarding shad which
lacked the one particular key scale. The key
area is on the left side of the fish, just dorsal to a
midlateral line and midway between the posterior
edge of the operculum and the origin of the dorsal
fin. A dozen or so scales from this area were
placed in a scale envelope on which was recorded
the information pertinent to the fish.

Three nonregenerated scales were taken at
random from these key-area scales. For study,
they were either impressed on strips of plastic by a
cold roller press (Smith, 1954) or mounted dry on
glass slides.

The scale measurements were obtained from
scale images projected by a microprojection ap-
paratus of the type described by Van Oosten,
Deason, and Jobes (1934).

Computations of growth from scale measure-
ments were made nomographically.

Weights are expressed in grams. The largest
fish were measured to the nearest gram, fish be-
tween 100 and 200 mm. in standard length to the
nearest 0.5 g. and those smaller than 100 mm. to
the nearest 0.1 g. In catches of large numbers of
gizzard shad smaller than 50 mm., those of equal
length were weighed en masse and the average

GIZZARD SHAD IN WESTERN LAKE ERIE

weight assigned to each member. Fish preserved
for a few days in formalin were sometimes used.
Some fish were not weighed when collections were
large. Gonads — only from freshly caught shad —
were weighed to the nearest 0.01 g.

Ovaries from potential spawners caught in May,
June, and July were used for egg counts. From
one of the weighed ovaries a small transverse
section (1 to 2 g.) was removed and weighed on an
analytical balance, its content of current-season
eggs counted, and the number of eggs in the entire
ovary calculated.

Histological preparations were made of the
ovaries of some fish captured in different seasons
for studies of oogenesis and ovarian growth and
development.

Sex was always determined by dissection except
for those fish from which eggs or milt were flowing
during the spawning season. When possible, sex
was determined for all fish longer than 120 mm.
Maturity of males could not be determined in the
absence of flowing milt.

SCALE OF THE GIZZARD SHAD
Description of the Scale

The gizzard shad has cycloid scales whose
annual growth zones contain many circuli. The
relatively closer juxtaposition of the circuli in the
first growth zone than in the succeeding zones con-
tributes a darker appearance to this inner portion
of the scale. The closely set circuli of this zone
are gently arched and, save for those formed
earliest, do not curve enough at their ends to
reach the transverse groove that separates the
anterior and posterior fields but terminate in the
lateral fields. This pattern is followed by the
circuli of each succeeding growth zone; i.e., the
earliest circuli reach the transverse groove, while
those produced later terminate laterally. The
first circulus of the second growth zone is closely
juxtaposed to the last circulus of the preceding
zone in the anterior field, cuts across the paths of
the later first-zone circuli at their terminations
in the lateral fields, and intersects the transverse
groove. Thus, it forms roughly a semicircle
around the first growth zone. The junction
between the first and second growth zones (fig. 2)
illustrates one type of demarcation line in the
gizzard shad scale. The first annulus of all shad
scales examined was of this type. Since this
annulus normally is evident only in the lateral

395

fields where the termination of the circuli of the
first zone is "cut across" by the circuli of the
second zone, it may escape notice under low
magnification.

A second type of demarcation line, characterized
by a narrow band devoid of clear-cut circuli,
normally is found between all growth zones be-
yond the first. Here, too, the earlier circuli of the
more recent zone cut across the paths of the later
circuli of the preceding zone in the lateral fields.
This type of annulus is clearly evident under low
magnification (fig. 3).

Further study is required, but on the basis of my
observations I suggest that this second type of
annulus is a combination spawning mark and
annulus. It is found only on the scales of fish of

Figure 4. — Second annulus of a gizzard shad scale
resembling typical first annulus.

Figure 2. — The first annulus of a gizzard shad scale.

Figure 3. — The second annulus of a gizzard shad scale,
with clear line between second and third growth zones.

spawning age. The prominence of this annulus
and its possession of a few fragmentary circuli
indicate not only a cessation and resumption of
growth, but also a period of either poor circulus
formation or even of limited scale resorption.
Such a period is not indicated by the first annulus.
Annulus formation and spawning take place at
about the same time (see next section on time of
annulus formation). Although no direct causa-
tive relation between spawning and annulus
formation has been demonstrated, the period of
disturbed circulus formation may well be the
result of rapid prespawning gonad growth. A few
gizzard shad do not spawn during their third year
of life (near the start of which the second annulus
is formed) . These fish may provide the scales on
which the second annulus resembles the normal
first annulus closely. This type of annulus (fig. 4)
lacks the narrow band of fragmentary circuli
which makes the usual second and succeeding
annuli so conspicuous.

Further evidence on the.possible effect of spawn-
ing on scale structure comes from gizzard shad that
show an accessory check between the first and
second annuli of their scales (fig. 5) ; in fact, all
accessory checks found were in this position. Fish
with this check may be the few shad which spawn
during their second year of life. Because the first
annulus is already present by the first of June,
whereas any precocious second-year spawning
occurs in late July — or later in the year (see
section on spawning season) — the effect of this
late spawning, if it is to be shown by the scale,
would have to appear beyond the first annulus.

396

U.S. FISH AND WILDLIFE SERVICE

Figure 5. — An accessory check on a gizzard shad scale.

Time of Annulus Formation

No new annuli were observed on the scales of any
age group of gizzard shad collected in the lake prior
to the second quarter of May (table 3). Data for
individual days in this second quarter indicated
that two of the five males and eight of the nine
females of age-group I, taken in the open lake on
May 15, had already formed their first annulus.
Only one other of the I-group fish, a female cap-
tured on May 12, 1955, collected in this quarter
had the new annulus. No fish of this age group
exhibited annuli in the small collections of May
16-23. (All of the 48 male and 56 female I-group
fish caught in Sandusky Bay on May 22, 1953, had
their new annulus — data not given in table.) All
I-group shad collected after May, however, had
completed the new annulus. The new annulus of
the Il-group fish began to appear in the first
quarter of June and the year-mark was present in
all of these fish by the first quarter of July. Shad
older than the Il-group seem to have formed the

new annulus about a week later; data for these
higher ages, however, are meager. The time of
annulus formation, as judged from examination of
scales, is in general agreement with the time of
resumption of growth in length as indicated by
changes in the length of fish (see fig. 8).

Once annulus formation had started, the per-
centage of females having the new annulus was
greater than that of the males until all fish of both
sexes had new annuli. On the whole, the female
gizzard shad seems to form the annulus as much as
a week earlier than the male.

Among the Il-group shad, neither length nor
weight of either sex was a determining factor in
time of annulus formation (a similar study was
not made of other age groups). A comparison
(made only for June) of the Il-group female
gizzard shad which had not spawned with those
which were spent demonstrated that the percent-
age of fish having the new annulus was about the
same in both groups. Hence, we may assume
that the act of spawning neither hastened nor
retarded the formation of the new annulus. It
may not be concluded, however, that the gonad
development which ultimately results in spawning
has no effect on the structural appearance of the
developing annulus or upon the initiation of a
check. Probable evidence of the effect of spawn-
ing is seen in the accessory check found between
the first and second annuli in the scales of some
shad (see previous section on description of the
scale) .

Validity of the Annulus as a Year-M?rk

Lagler and Applegate (1943) and Lagler and
Van Meter (1950) demonstrated that the annulus
is a true year-mark on scales of gizzard shad in
Indiana and Illinois. The following data on shad
in Lake Erie add support to the belief that annuli

Table 3.- — Percentage of gizzard shad having a new annulus in May, June, and July
[Combined collections of 1953-55; lake specimens only. Number of fish in parentheses]

Age and sex

Periods in May

Periods in June

Periods in July

1-8

9-15

16-23

24-31

1-8

9-15

16-23

24-30

1-8

9-15

16-23

24-31

I-group:

Male

Female. ..
Il-group:

Male

Female. ._
III-VI-group:

0.0 (51)
.0 (74)

.0 (23)
. 0 (34)

0 (3)
.0 (3)

9.1 (22)
23.7 (38)

.0 (37)
.0 (48)

0. 0 (4)
.0 (1)

.0 (23)
.0 (37)

.0 (6)
.0 (4)

0.0 (4)
.0 (1)

100.0 (10)
100. 0 (8)

24.2(120)
32.8 (67)

.0 (16)
.0 (5)

8.4 (166)
30. 7 (75)

. 0 (26)
.0 (8)

100. 0 (83)
100. 0 (37)

52.0 (246)
66.4 (125)

.0 (24)

16. 1 (31

100.0 (18)
100.0 (19)

84.9 (86)
96.9 (97)

50. 0 (2)
75.0 (32)

100.0 (50)
100.0 (75)

100.0 (29)
100.0 (47)

75. 0 (4)
100.0 (26)

100.0 (1)
100. 0 (3)

100. 0 (7)
100.0 (13)

100. 0 (1)
95.2 (21)

100.0 (55)
100.0 (71)

100.0 (27)
100.0 (16)

.0 (1)

100.0 (21)
100.0 (20)

100. 0 (2)
100. 0 (5)

Female. ..

.0 (5)

GIZZARD SHAD IN WESTERN LAKE ERIE

397

are valid indicators of age. (Later sections in-
clude considerable supporting data on certain of
the points.)

1. Gizzard shad known to be young of the year
had no annuli on their scales.

2. The scales of these young shad captured in
the fall, winter, and early spring showed no an-
nulus at the edge, whereas those taken later
exhibited increasing percentages with an annulus
until all possessed them.

3. The distance between the last annulus and
the scale edge increased through the growing
season.

4. Presumed age groups as indicated by modes
in length-frequency groupings of shad agreed with
groupings based on the number of annuli.

5. The calculated lengths for particular years
of life among the age groups of the same, and
different years of collection agreed with estimates
of length from modes of frequency distribution.

Body- Scale Relation

The relation between fish length and scale length
in gizzard shad was determined from the "key-
area" scales of some 700 fish, ranging in standard
length from 43 to 390 mm. A test plotting of the
length of the anterior radius (center of focus to
anterior edge) of the scale against the standard
length of the fish indicated the relation to be
linear. The regression line, Z=22.1-f 44.25 S,
was fitted by least squares; Z=standard length
of the fish in mm. and S= anterior radius of the
scale in mm. Fish captured in every month and
including age-groups I through VI of both sexes
are represented in this equation. Studies of the
body-scale relation for each sex, for each age
group, and during each month revealed no appre-
ciable variation from the general equation.

The empirically derived body-scale equation
was the basis for construction of a nomograph for
the calculation of growth from scale measurements.

AGE COMPOSITION

Seasonal movements, segregation by size and
possibly by maturity, and selectivity of collecting
methods complicated the problem of sampling
for age composition. The very young gizzard
shad of western Lake Erie were found in mid-
summer close to shore, usually in shallow water.
Collecting representative samples of these fish
presented difficulties. Capture of the very

youngest required the use of dip nets which, of
course, the larger fish eluded. As the season
progressed and the fish grew larger, Common
Sense seines and bag seines were used, but this
gear permitted the very smallest fish to pass
through the meshes while many of the larger
ones escaped capture by their agility and speed.
The use of rotenone was selective for the very young
shad that could not swim through the poisoned
water rapidly enough to avoid being overcome.
(Rotenone was used in small areas in the lake
with no provisions for holding the fish within the
sampling area or for preventing dissipation of the
poison into the surrounding waters.) Electrocut-
ing, on the other hand, was selective for the larger
shad — the very young ones were unaffected.
Finally, I used dynamite. This method proved
must successful because fish of all sizes and ages
surfaced within the radius of its effectiveness.

As the young gizzard shad become larger
(and older) they move into deeper water offshore.
By October, the Common Sense seine, which
must be fished inshore, will capture some O-group
shad but no I-group or older ones; hence, its
catches yielded no data on age composition.
The gill net captures large O-group shad and also
all the older age groups in October, but many
smaller O-group shad must pass through the
net. Because of these sampling problems, esti-
mates of age composition are unreliable among
the 4- to 8-inch shad. Only a few fish of these
sizes were captured by experimental gill nets
whose meshes ranged from 1 to 4 inches, stretched
measure.

Except during the spawning season, gizzard
shad older than age-group III were rarely found
in the shallower waters. This preference for the
deeper water seemed to increase with age.

In view of the segregation by size and the sea-
sonal changes of distribution, small-scale methods
of collection could not provide suitably accurate
data on age composition. I lacked especially
the means to compare data on the 1- to 4-inch
group from the shallow waters with records
for larger shad from the deeper waters.

Seasonal Changes of Age Composition

Because of the difficulties just outlined, O-group
gizzard shad caught by any means other than by
trap nets and 4-inch-mesh gill nets have been
excluded from this section. The O-group shad

:;<tx

U.S. FISH AND WILDLIFE SERVICE

in our collection area appear in June, rise to
greatest abundance about late July, and diminish
in numbers thereafter. Greatest losses occur,
presumably, as a result of predation and migra-
tion from the collection area.

Although O-group gizzard shad were taken in
greatest numbers in late July, none of them had
become large enough to be caught by the gill
nets and trap nets until August. Subsequently,
the size of the collections of the O-group coming
into this catchable size range increased regularly
until they reached peak abundance toward the
end of the calendar year (table 4). They were
the dominant age group among fish taken by
these nets from August to the end of the year.
From January to August of the next year, con-
trary to expectation, these fish, as the I group,
were not dominant in the catch of gill nets and
trap nets. Over this period the II-group fish
dominated the catches. After August, however,
the I group became more plentiful than the older
groups and maintained that abundance thereafter.

The scarcity of I-group gizzard shad in the gill
net and trap net samples from January to August
cannot be fully explained. When all the fish
captured in January-July are considered (whether
they were obtained by dynamite, rotenone,
electrocution — data not tabulated here), then the

Table 4. — Age composition of gizzard shad taken by trap
nets and Jf-inch-mesh gill nets, Lake Erie, 1954

[Percentages of fish in age-groups I-VI given in parentheses— the O-group
fish were not considered in the computation of percentages or average age]

Age group

Total
and

Month

III

aver-
age
age'

(2)

(2)
256
899
667
1,686
320

(8.2)

(16.5)

(8.7)

316

(45.8)

190

(47. 6)

(2.4)

287

(37. 4)

226

(89. 0)

304

(97.0)

221

(93. 2)

164

(98. 8)

(95. 1)

(89. 8)

(76.7)

(69. 6)

330

(47. 8)

187

(46.9)

1.656

(89. 9)

446

(58.1)

(10.6)

(2.2)

(6.3)

0.2)

(4.9)

(2.0)

(4.1)

(21.7)

(5.2)

(4.0)

125

(6.8)

(3.8)

(0.4)

(.4)

(.5)

1.94

Feb

(2.7)

1.93

2.13

(1.0)

(1.3)

(0.8)

(.5)

(0.1)

(■3)
2

(1)
1

(.1)

(0.1)

(.1)

690

1.62
399

1.60
1.843

July

2.07
768

1.68
254

1.11

Sept

(.4)

313

1.04

Oct

237

1.07

166

1.01

Dec. .

102

1.05

1 Average number of annuli.

2 Young of the year first became available to the nets in August.

I group is the dominant group in the collecting
area in all the early months except June and
July. The June collection especially is note-
worthy— the I group was very poorly represented
in samples from both the lake and Fishery Bay —
especially in the bay where only 4 I-group shad
were collected along with 820 II-group fish.

It is noteworthy that the II-group and older
shad were taken principally in April through
July. Only during the spawning season (June-
July) was I able to capture the Vl-group shad,
which were the oldest in the samples. The
August-September samples were dominated over-
whelmingly by age group I (89.0 to 98.8 percent).
The II group made up 1.2 to 10.6 percent, and
only four older fish were taken in the 5 months.

Sampling difficulties, as previously described,
prohibited any detailed consideration of fluctua-
tions of year-class strength; however, the 1952
year class apparently was one of unusual abun-
dance. In random samples from commercial trap
nets this year class made up 85 percent of the
total as age group I, 71 percent as age group II,
and 11 percent as age group III.

Survival Rate

Although the records (table 4) do not give a
fully satisfactory idea of the age composition of
the gizzard shad stock, the collections made in
April-July probably permit fairly reliable inference
as to the ratios between the numbers in successive
age groups for II-group and older shad, since these
mature fish seem to constitute a homogeneous
group during this period. Collections made from
August to December are probably reasonably
reliable for determining the ratio of the I-group to
the II-group shad. From these two sets of data,
I have estimated the survival rate of shad from
one age group to the next higher one (table 5).

An estimate (not given in table 5) was made also
of the survival of gizzard shad from egg deposition
to age-group I. The first step was the calculation,
from data on sex ratio (table 15) and fecundity
(table 18), of the probable number of eggs de-
posited by the gizzard shad of age-group II and
older. The females of the 6,049 fish (total of the
II-group and older of the right-hand column of
table 5) were thus estimated to have deposited 926
million eggs. If the 100,000 I-group fish of table 5
are held to be the survivors of this number of eggs
(it is assumed that the population is relatively

GIZZARD SHAD IN WESTERN LAKE ERIE

399

stable), survival from the egg to age-group I is
determined as 0.011 percent. This estimate is
beset with many uncertainties. It assumes, for
example, that the determination of the number of
I-group individuals from the ratio of numbers of
fish in age-groups I and II in August-November
samples was accurate; that year-to-year differ-
ences of stock were small enough to justify the
pooling of data in the preparation of table 4;
that the samples that contributed to table 5 were
not unduly biased by gear selection or segregation
by size or sex. Even if we granted the survival
of 0.011 percent from egg to I-group a wide margin
of error, however, the extremely low value still
indicates an enormous mortality.

The extraordinarily low survival of the gizzard
shad from eggs to the I-group fish probably results
from heavy egg and larval mortality, predation,
and (in late fall and early winter) buffeting
during storms as well as rapid variations in
water temperature. When they become the I-
group fish, they are usually too large to be eaten
by most predatory fish, but they are susceptible to
storms and temperature changes that are greatest
in waters relatively close to shore where this age
group is usually found. As the shad become older,
the survival rates improve, probably because the
fish tend to remain in the deeper waters where
they are less subjected to climatic disturbances.

The oldest gizzard shad that I collected from
the western end of Lake Erie in 1952-55 were
three of age-group VI (seventh year of life).
Patriarche (1953) reported X-group gizzard shad
from Lake Wappapello, Mo.

LENGTH-WEIGHT RELATION

General Relation

The mathematical relation between length and
weight of gizzard shad captured in western Lake
Erie in 1952-55 was determined by fitting the
equation W=cLn to the average empirical lengths
and weights of fish in each 10-mm. length interval.
The length-weight relation was investigated for
each month in which sufficiently large samples
were taken. Between mid- 1952 and mid- 1955
there were 25 such monthly samples. At least one
equation was determined for each of the 12 months
(for some months adequate samples were acquired
in each of the 2 or 3 years — hence, two or three
equations). For a month having more than one
equation, length and weight data were obtained by

Table 5. — Survival of gizzard shad from one age group to
the next higher one

[The figures in the first column, body of table, obtained from table 4)

Period of capture and age group

Number
offish

Survivors

from

100,000

I group

August-December

I _ _._.

1,012
56

2,619

206

100,000

II...

5,534
5,534

April-July

III

435

V...

VI..

each equation, and from these an average monthly
length-weight relation was determined. In like
manner a "general" length-weight equation was
determined from the data calculated by the
monthly equations. The sexes were combined for
all monthly equations. The general equation was
log W= -4.81765 + 3.07053 log L, where IF is the
weight in grams and L is the standard length in
millimeters.

1200

0 50 100 150 200 250 300 350

STANDARD LENGTH (MILLIMETERS)

Figure 6. — Length-weight relation of gizzard shad in
western Lake Erie. The curve is a graph of the general
length-weight equation; the data represent the mean
empirical values, derived as explained in the text, for the
combined collections of 1952-55.

400

U.S. FISH AND WILDLIFE SERVICE

Table 6. — Empirical weights and weights calculated by the,
general length-weight equation for gizzard shad in western
Lake Eric, 1952-55

0 50 100 150 200 250 300 350

STANDARD LENGTH (MILLIMETERS)

Figure 7. — Length-weight curves for gizzard shad from
Lake Erie, Missouri, and Illinois. Left curve, Lake
Erie; middle curve, Missouri; right curve, Illinois.

Empirical weights and the weights calculated by
the general length-weight equation (table 6 ; fig. 6)
agreed well in view of the heterogeneous nature of
the materials (records of weight were combined
without regard to season, year, sex, maturity, or
method of capture). Largest disagreements in
measurements concerned the longest fish.

Patriarche and Lowry (1953) determined the
length-weight equation to be log W= — 2.2071
+ 2.9812 log L for gizzard shad in the Black River
Basin of Missouri. Lagler and Van Meter (1950)
reported the equation to be log W= — 2.2789
+ 3.034 log L for shad in Illinois. In both equa-
tions, the units are weight in ounces and total
length in inches. The curves based on these
equations show the Lake Erie shad to be heavier
for corresponding lengths than those in Missouri
and Illinois (fig. 7).

The weights of male and female gizzard shad
were closely similar except in June and July,
when the females were consistently heavier than
males of corresponding length. This difference
frequently has been explained on the basis that

GIZZARD SHAD IN WESTERN LAKE ERIE
774-711 O— 66 8

Standard

Weight

Standard

IrilKl h

Weight

length

Empirical

Calculated

Empirical

Calculated

Millimeters
20..

Grams
0.08
.5
1.3
20
26
35
43
54
67
82
99
118
138
161
194
215

Grams
0.15
.5
1.3
19
25
33
42
54
67
82
99
119
141
165
193
222

Millimeters

226

236.

246

256

266

276

285

295

305

315

326..

335

344

355

365.

377.

Grams
251
289
328
373
428
484
525
581
629
680
776
781
876
937
1,034
1,179

Grams
257

295

40.__

333

96.,

376

106..

424

116

473

125

526

136

583

146

645

156

713

166

794

176 _-

864

186

938

196, _

1,032

206....

1,118

215

1,234

the female's ovaries are heavy with eggs soon to
be spawned. Although the weight of the ovaries
contributes strongly to the heavier total weight
of the female gizzard shad, it does not explain
it entirely. To investigate this point, the body
weight (exclusive of gonad weight) of both sexes
should be compared. Unfortunately, I had
taken relatively few gonad weights of males —
and these over a period of several months which
cut across the seasonal changes of weight. How-
ever, since the testis weight averaged 1.4 percent
of the body weight for these males, I thought I
could eliminate the greater part of the weight
advantage offered by the ovary by adjusting the
female shad's weight to include ovaries weighing
only 1 percent of her body weight.

The adjusted weights of these fish were still
greater than those of male shad of corresponding
length (table 7). The lesser weight of males may
result from their greater activity during the
spawning season.

Effect of State of Ovaries on Weight

The study of the effect of the state of develop-
ment of the ovaries on the weight of the fish was
based on records for three categories of fish caught
in June 1955: will not spawn, will spawn, and
spent.

The gizzard shad that would not have spawned
were the heaviest ( cble 8). The average weight
of females which would have spawned was 96 per-
cent of that of the shad which would not have
spawned. It appears that the production of ma-
ture eggs for spawning reduces the fish's total
weight — possibly because some food is stored as

401

Table 7. — Comparison of weights of male shad at 20-mm.
intervals with those of females whose weights have been ad-
justed to include ovaries of only 1 percent of their body
weight

[Based on June 1955 collection]

Standard length

Weight

Males

Females

Millimeters
200...

Grams
158
210
271
344
428
525
636
760
900

Grams
189

220

244

240....

309

260

383

280

467

300

563

320

669

340

788

360

919

oil in the eggs rather than as the heavier protein
of flesh. The spent fish weighed the least. Their
average weight was 85 percent of that of the fish
which would not have spawned during the current
season. The average percentage loss of weight of
mature females at spawning increased with length
of fish and averaged 10.7 percent.

Seasonal Differences in the Weight of Fish of a Given
Length

The weight of gizzard shad of a given length
varies from season to season, and this seasonal
variation is similar from year to year. The na-
ture of the seasonal changes (table 9) appears
from the average monthly length-weight data. In
June and July, when weights of the sexes differed
appreciably, the males and females were treated
both separately and combined; in other months
they were combined.

Gizzard shad attained their greatest weight in
August-October, after which the weight declined
slowly and irregularly, reaching a low for the com-
bined sexes about May-June. (Interpretations

are handicapped by differences of slope in the
monthly logarithmic lines.) During the next 2
months, the weights increased rapidly. The
weight of the female was least in May (not shown
in table 9), and an increase was obvious in June,
but that of the male reached the lowest point in
June.

Studies of the gut contents indicate that gizzard
shad consume little food in winter and early
spring. During this period they subsist largely
on energy stored in the body tissues. Because
metabolic rates are low in winter, decrease of the
body weight is slight. As the water temperature
rises in early spring, the metabolic rate of the
fish increases more rapidly than the rate of food
intake and the body weight decreases more
rapidly. This process gains momentum with the
progression of spring until about May-June when
the lowest body weight is attained apparently
just before the renewed feeding begins to meet
the energy requirements of the fish. The occur-
rence of peak weight, in August-October, un-
doubtedly is directly related to feeding.

Continued loss of weight in June among the
males can be attributed to their spawning activities.

Table 8. — Weights of three groupings of female gizzard shad
of different ovarian development, June 1955

Weight of females in

category

Standard length

Would not

have
spawned

Would

have

spawned

Spent

Loss at
spawning

Millimeters
280..

Grams
510
610
722
846
982

Grams
484
583
694
818
954

Grains
473
543
617
695
779

Percent
2.3

300

6.9

320

11.1

340

15.0

360-

18.3

Table 9. — Monthly variations of weight of gizzard shad as determined from the monthly length-weight equations

WEIGHT

402

U.S. FISH AND WILDLIFE SERVICE

Table 10. — Annual differences of weights of gizzard shad in 1952-66
[Years compared by pairs; data limited to months for which records are available for both members of the pair]

Standard length

Weights by years

1952

1953

1952

1954

1953

1954

1953

1955

1954

1955

Millimeters
200

Grams
190
253
330
421
525
650
790
950
1,146

Grams
186
249
326
416
523
645
787
948
1,130

Grams
197
264
345
442
555
686
837
1,008
1,204

Grams
189
252
326
415
517
636
771
924
1,096

Grams
172
231
303
389
490
608
744
898
1,078

Grains
174
237
312
403
510
636
781
948
1,138

Grama
154
207
272
348
440
546
668
807
966

Grams
169
226
296
379
476
590
720
869
1,036

Grams
165
223
293
378
478
595
730
885
1,061

Grams

172

220 --

229

240

297

260

378

280

472

300

581

320

705

340

846

360 .

1,005

1952 > 1953

1952>1954

1953<1954

1953 < 1955

1954 > 1955

Aug., Nov.

, Dec.

Aug.

Jan., Feb., Apr.,

Feb., Apr., May

Feb., Apr., May, June

May, Aug., Oct.

Annual Differences in Weight

The study of the annual differences in the length-
weight relation of gizzard shad in 1952-55 was
based on data for only those months during which
adequate collections were made in at least two of
these years. As was brought out in the previous
section, the weight of shad varies with the season.
Since samples were not adequate for determination
of length-weight relations for every month of each
year, the use of yearly data would result in a bias
in favor of the year during which the specimens
were obtained in the months of greatest weight.
Consquently, the paired comparisons for 1952-55
were based only on data from months common to
both years being compared (table 10).

Shad were heaviest in 1952 and lightest in 1953.
The rating of years ran: 1952>1954>1955>1953.

LENGTHS AND WEIGHTS OF AGE
GROUPS

The average size of the members of an age group
varies with time of capture within the year along
clearly seasonal lines. The monthly average
lengths of shad show little growth in early spring,
rapid growth in summer and early fall, and
apparently a cessation of growth in winter for
both sexes and all age groups (table 11). The
course of growth becomes more apparent when
portrayed graphically (fig. 8). After about June
of their second year of life female shad were
rather consistently longer than males of corre-
sponding age.

The average monthly weights of shad showed,
in general, a gradual decrease from the first of the
year until June (table 11; fig. 9). This decline

_**"

" ' f'\ ■

•^

. V*

. . S*

J 0

0 GROUP

J A J 0
I GROUP

J A J 0
II GROUP

J A J 0
in GROUP

J A J 0
E GROUP

J A J 0
IT GROUP

J A i

v: i ,!■.■. >i i

Figure 8. — Lengths of gizzard shad at capture in each
month by age and sex. Dots are empirical averages of
standard length. Open dots represent females; solid
dots, males. Curves were drawn by inspection.

was followed by a rapid rise in late summer and
fall. Seasonal variation of the length-weight
relations (see earlier section) contributed to these
changes. The female shad were heavier than
males after about June of their second year of life.
The average monthly lengths of the O-group
shad warrant special comment. Because some
gizzard shad can be found in the spawning state
in western Lake Erie from early June to mid-
July (see section on length of spawning season),
every sample of young shad collected usually
contained fish hatched over a period of time, the
extremes of which often differed in age by as
much as a month or more. The successive col-
lections continually yielded low average changes
in length because of the great percentage of the
newer, smaller shad constantly added to the
population. This bias was aggravated by the
tendency of the larger O-group fish to move off-

GIZZARD SHAD IN WESTERN LAKE ERIE

403

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404

U.S. FISH AND WILDLIFE SERVICE

shore from the sampling area and their growing
ability to avoid capture. As a consequence, the
sequence of these low average monthly lengths
cannot be construed to indicate the rate of growth
for these young shad. It was held desirable,
therefore, to estimate the position of certain points
and of the curve in the preparation of figure 8.
No precise quantitative justification can be given
for these estimates, but they were based on broad
sampling experience and extensive observations
on catches in inshore waters. The estimates
are held surely to be superior to judgment based
on the sadly biased sample records. The curve
and points of figure 8 beyond age-group O are
based strictly on the records of table 11. The
records of monthly growth of table 12 were read
from the curve of figure 8.

Gizzard shad of age-group O presumably
grew most rapidly in July, August, and September
and had peak growth in August. The record
for I- and II-group shad indicates that growth
in length of the I-group fish progresses rapidly
earlier in the year than it does for the Il-group.
Greatest gain occurred a month earlier — in July.
Growth was slight for both groups during May
and for the I-group after September.

During the second year of life the male shad
grew in length 57 percent as much as during the
first year, and in the third year, 28 percent as
much. For the female shad the second- and third-
year growths were 66 percent and 34 percent,
respectively, of the first-year growth.

Seasonal changes in weight resemble those in
length (compare figs. 8 and 9) except that weight

decreases over winter from the peak attained dur-
ing the previous fall. The basis for this change
was explained earlier in the section on seasonal
changes in weight.

Attempts to follow seasonal growth of gizzard
shad by use of tagged individuals were unsuccess-
ful. No fish were recaptured from some 600 tagged
during the winter of 1952.

CALCULATED GROWTH

Calculated Lengths of Age Groups

The dependability of calculations of length at
time of annulus formation is indicated by com-
parison of the calculated lengths and the lengths
of shad which were captured between the end of
the growing season and the time of annulus forma-
tion (first and last columns of table 13). Because
the annuli are the only landmarks on the scale
which can be related to a somewhat definite time,
and because the shad has practically the same
length from the beginning of the calendar year to
the time of the annulus formation, the length of a
shad captured in this period should agree closely
with the length calculated from an older fish to the
corresponding annulus.

Agreement was close among adequately repre-
sented age groups except for the I-group shad.
In the compilation of the empirical data for this
group, 105 shad had to be eliminated because sex
could not be determined with certainty; their
average standard length was 129 mm. Had they
been included, the disagreement between empirical
and calculated lengths would have been less, but

Table 12. — Progress of season's growth in length of gizzard shad by millimeters and percentage

[Lengths taken from the curves of figure 8]

I-group

II-group

O-group

Male

Female

Male

Female

Afi

siS

■a

«3

Period

§5

o3
35

•35

bD+J

Ox:

o>.a

03 b£

§s

■a

> §
<-

2 m

gfe

£ °

o &

8.9

s &

O DC

£ a

O fc

gfe

£.9

£.g

£9

■<

Per-

Mm.

cent

Mm.

cent

Mm.

cent

Mm.

cent

Mm.

cent

Apr. 30

167
175

164
175

0
10

263
266

0
3

0
6

273
276

0
3

0
5

May 30

i 5

June 30 ...

22
50
114

17
28
64

13
30

10
17
39

199
225
249

24
26
24

60
85

25
27
25

204
233
257

29
29
24

37
64
85

27
27
21

271

282
297

5
11
15

17
40
72

11
23
32

282
294
309

6
12
15

16
38

Julv30

Aug. 30

Sept. 30

155

258

268

305

320

Dec. 30

165

100

263

100

273

100

310

100

328

100

1 These fish are assumed to be about a week old. Shad hatched in the laboratory were 3.5 mm. in standard length and became 5.2 mm. long in 4 days.
GIZZARD SHAD IN WESTERN LAKE ERIE 405

Figure 9. — Weights of gizzard shad at capture in each
month by age and sex. Dots are empirical averages.
Open dots represent females; solid dots, males. Curves
were drawn by inspection.

still substantial. The principal cause of the
discrepancy was probably the selective sampling
of age-group I. Many of this group were too
small to be caught by the gill nets and the trap
nets. At the higher ages the agreement between
empirical and calculated lengths was good. The
lengths calculated for each year of life from
progressively older shad show a similar close
agreement except for the first year of life.

No year classes exhibited consistently fast or
slow growth in length, nor did growth appear to
have been outstandingly good or bad in any
particular calendar year.

Compensatory Growth in Length

It has been observed frequently that although
the larger of the young fish maintain a length
advantage over the smaller ones during subsequent
growth, the smaller young fish grow more rapidly
during subsequent years than the larger ones and,
thus, reduce progressively the original length
difference.

To study this "compensatory growth" in gizzard
shad, I tabulated the annual increments of growth
of Ill-group fish, arranged by 20-mm. groupings
of length at the end of the first year of life (table
14). The sexes were treated separately, and only

fish caught in 1954 were used. In both sexes the
annual increments generally varied inversely with
first-year length; consequently, the difference in
length between the shortest and the longest
first-year fish diminished progressively to a mini-
mum in the third year.

Table 13. — Comparison of the average empirical standard
length of gizzard shad with average length calculated for
each year of life for each age group for each sex

[Fish of the same age were comhined without regard for year classes. Em-
pirical lengths are given only for shad captured between the end of the
growing season and the time of annulus formation. Number of fish in
parentheses]

Sex and year of life

Average

empirical

length

Age group

Average
calculated

III

lengths !

Male:

First

Mm.

165

(227)

273

(530)

313

(53)

328

(8)

350

(1)

162

(267)

283

(489)

335

(83)

361

(17)

383

(4)

Mm.
146
(76)

Mm.
130
(92)
270
(37)

Mm.
145
(34)
282
(34)
316
(5)

Mm.
146

(8)
270

(8)
312

(8)
348

(1)

Mm
139

(2)
270

(2)
310

(2)
337

(2)
349

(1)

138

(3)
282

(3)
336

(3)
369

(3)
390

(1)

Mm.
141

273

Third

313

Fourth

343

Fifth

349

Females.

First

134
(71)

139

(118)
285
(57)

146

(62)
292
(62)
336
(42)

144
(13)
280
(13)
333
(13)
362
(6)

140

285

Third

335

Fourth...

366

Fifth.

390

1 Unweighted means.

Table 14. — Average annual increments of length of Ill-
group shad of the 1954 collections arranged by 20-mm.
groups of first-year calculated length

[Second- and third

-year calculated lengths given in parentheses]

Males

Females

Number of
fish

First
year

Second
year

Third
year

Number
of fish

First
year

Second
year

Third
year

Mm.
96

109

132

154

173

185

Mm.

161
(257)

162
(271)

151
(2S3)

131
(285)

114
(287)

105
(290)

Aim.

49
(306)

36
(307)

31
(314)

28
(313)

31
(318)

25
(315)

Mm.

4...

114

169
(283)

160
(291)

139
(291)

135
(301)

124
(308)

(333)

10 .

131

(336)

10..

152

(334)

3 -

166

(339)

4 _-

184

(344)

Difference in

standard

length i

Difference in

length in-

9
24

25
45

11
14

' Between shortest and longest first-year groups.

406

U.S. FISH AND WILDLIFE SERVICE

REPRODUCTION AND EARLY
DEVELOPMENT

Size and Age at Maturity

The sex and maturity of gizzard shad were
always determined by dissection except for those
fish from which eggs or milt were flowing during
the spawning season. Vladykov (1945) stated
that the males have darker fins than the females,
but I found that neither this nor any other readily
discernible external characteristic indicated the
sex with reasonable consistency for all age groups
in all seasons. Generally, however, one might
expect a shad that is relatively deep for its length
to be a female. Since the time of this study,
Moen (1959) sexed gizzard shad by examining
the urogenital opening with a probe.

The sex of large fish was determined easily —
the testes were opaque white, whereas, the ovaries
were mostly semi translucent and light yellow or
pink. Sex determination was more difficult in
small shad. Here, the testes were whitish and
the ovaries almost colorless and translucent, but
the distinction between them became less and less
apparent as one examined smaller and smaller
gonads. After much study (comparisons of judg-
ments from macroscopic examination with subse-
quent determinations from histological sections) I
could frequently distinguish the sexes macroscopi-
cally when the diameter of the gonad was only 1
mm. and readily when it attained 2 mm. The
minimum standard length of fish for which sex
could be determined macroscopically with confi-
dence was about 120 mm. (4 or 5 months old),
although on occasion sex could not be determined
for a larger shad.

Although a fish whose milt or spawn flows
during the spawning season is sexually mature,
the absence of this feature does not indicate im-
maturity. In this situation, during the spawning
season or any other time, different criteria must
be employed. Histological studies of ovaries
collected throughout the year have enabled me
to recognize a potential spawner several months
in advance of the spawning season and spent fe-
males as long as a month after spawning. More-
over, the relation of the histological characteristics
of the ovary to the gross appearance of that organ
made possible an estimate of maturity by gross
observations. In females that will not spawn, the
ovaries contain only minute, scarcely visible eggs,

whereas potential spawners exhibit, in addition to
the minute eggs, fair-sized ones that are clearly
visible within the semitranslucent ovary several
months prior to spawning. Although completely
spent females have only the minute eggs that are
characteristic of the ovaries of fish which will not
spawn, their ovaries for a few weeks after spawn-
ing are more flaccid than those of nonspawners,
the minute eggs are some little distance apart,
and the interovular spaces have a more watery
appearance.

The maturity of males could not be determined
in the absence of flowing milt. The presence of
motile sperm, obtained by lancing a testis, does
not assure maturity. Males examined in January
had motile sperm — even the I-group males, most
of which would not spawn in the spring. Maturity
in males is undoubtedly associated with structural
development or physiological change which per-
mits release of the sperm. The great scarcity of
I-group males at the spawning site in May and
June suggests that this release mechanism does
not usually become functional in males of that
age. The presence of a few of them on the spawn-
ing grounds during July may indicate that some
have matured near the end of the spawning season.

In 1954, I found three mature I-group female
shad. Their standard lengths were 197, 225, and
236 mm. Some 25 or 30 I-group males, 190 to
230 mm. long, also were mature. The milt and
spawn produced by fish of this age were scanty.
The crosssection of an ovary of a mature I-group
female reveals few mature eggs (fig. 10).

Figure 10. — Cross section of an ovary of a mature I-group
gizzard shad showing relatively few near-mature eggs
(July 6, 1954).

GIZZARD SHAD IN WESTERN LAKE ERIE

407

Invariably, these precocious fish arrived at the
spawning site in July, near the end of the spawn-
ing season. They were not the largest of their
age group, whose length range extended to 254
mm. at this time, but were generally above the
average length. They obviously represented only
a fraction of their group, but the exact percentage
could not be determined because segregation ac-
cording to maturity is great during the spawning
season.

Most spawners were in their third year of life
(II group), but not all shad of this age group
spawned. The average length of the June 1954
II-group females that would have spawned (29
cm.) was 1 cm. greater than that of the shad

Table 15. — Sex ratios for gizzard shad for which both sex and

age were determined monthly
(These shad were captured in the vicinity ot the Bass islands in 1952-55]

Month and sex

Age group

Total
for

III

month

January:

50.0

31.8

33.3

151

177

46.0

41.0

50.0

121

166

42.2

104

100

51.0

118

159

42.6

123
99

55.4

44.2

38.1

31.1

135

104

56.5

33.3

156

164

48.8

128

41.3

913

753

54.8

172
315
35.3

50.0

4
3

57.1

60.0

50.0

20.0

0.0

62.5

2
60.0

51.6

7
53.3

51.2

17.2

35.0

February:

66.7

150

123

54.9

March :

39.1

April:

42.9

57.1

4
10

28.6

328

361

100.0

47.6

May:

160

0.0

50.0

100.0

208

41.9

June:

1,004

849

54.2

July:

299

0.0

510

37.0

August:

119
116
50.6

410
516
44.3

319

352
47.5

827
S76
48.6

221
276
44.5

237

229

Percentage males..
September:

100.0

50.9

534

678

Percentage males. _
October:

100.0

44.1

451

0.0

458

Percentage males. .
November:
Male

49.6

901

969

48.2

December:

259

340

43.2

Total in age
groups:

1,896
2,136

47.0

812
967

45.6

1. 513

1.532

49.7

105
116

47.6

14
22

38.9

4.343

4 | 1
20.0 1 66.7

4,778

Percentage

47.6

which would not have spawned during the current
year (28 cm.). Although the percentage of the
female shad that matured during their third year
of life could not be determined because of the
segregation according to maturity, observations
on gonads of shad captured throughout the year
indicated that at least SO percent of them became
mature at this age in western Lake Erie. Only
rarely were female shad older than the II-group
immature. With few exceptions, the II-group
male shad had well-developed testes. Since, how-
ever, I was unable to determine maturity in the
absence of flowing milt, I could not distinguish
a spent individual from one which had not
spawned — in fact, could not judge from the state
of the testes in any month the percentage of
mature males of any age group.

Sex Ratio

The gizzard shad captured in the vicinity of
the Bass Islands in 1952-55 for which sex could
be determined were combined to show trends of
the sex ratio by month and by age (table 15).

Only limited seasonal trends are apparent from
the data on sex ratio; the month-to-month fluctua-
tions were decidedly irregular.

Among the 10 months in which the total sam-
ples exceeded 250 fish, July stands apart because
of the small percentage of males (37.0 percent).
Among the other 9 months, this percentage ranged
between 41.9 (May) and 54.9 (February). The
percentage for all 12 months was 47.6.

The percentage of males varied little among the
four younger age groups (45.6-49.7 percent males)
in the combined sample for all months, but males
became less numerous at the higher ages (38.6
percent in age groups IV-VI, combined).

Information on the percentage of males in
samples from the shallow waters of Fishery Bay
and the deeper waters of the lake gives no indica-
tion of segregation of the sexes within the lake
except for age groups II and III (shad of spawning
age) during June. The records for that month
(table 16) suggest that males are relatively more
plentiful at the spawning site than in the deeper
water. The data on sex ratio on the spawning site
during the spawning season are undoubtedly biased
in favor of the males since their greater activity
increases the likelihood of capture by the sta-
tionary fishing gear. This bias, however, does not
account entirely for the large percentage of mules

408

U.S. FISH AND WILDLIFE SERVICE

Table 16. — Sex ratios for gizzard shad caught in the shallow waters of Fishery Bay and in the deeper waters of Lake Erie

for June and for all other months combined in 1952-55

Month and site of

Sex

Age group

Total

capture

III

June:

5
6
45.6
16
15
51.fi

214
207

50.8
577
739

43.8

610

207
74.7
303
546
35.7

154
196

44.0
446
583

43.3

47
16

74.6
18
4fi

28. 1

50.0

41.5

665

229

100.0

28.6

2
33.3

37.5

74 4

2
0.0

1
50.0

342

620

35 6

All months except June:

63
82

43.4
1,833
2,054

47.2

438

493

47.0

2
33.3

1
100. 0

2,898
3,436

45.8

on the spawning site; in the deeper waters the
percentage of males is greater between spawnings
than during the spawning season.

The sex ratios of mature shad captured in
Fishery Bay and in the deeper waters of the lake
within 7- or 8-day periods in May, June and July
of 1954 and 1955 (table 17) indicate that the
percentage of males in the population of shad
captured in the bay increased during early and
mid-June and reached a high in the third quarter;
the females were relatively most numerous in the
last quarter. Males were scarce in deeper water
in June (exception, June 9-15), and with the
exception of one sample (July 1 6-23) , this scarcity
continued through July. Data are few on the
sex ratio in Fishery Bay in July; females pre-
dominated strongly in the single sample. The
generally small percentages of males in all July
samples account for the low monthly percentage
for July, mentioned in the earlier description of
table 15.

DEVELOPMENT AND MATURATION OF THE EGG

For convenience in description, the development
of the egg has been divided arbitrarily into six
stages (fig. 11). The following descriptions were
made from ovary sections fixed in Bouin's solution
and stained with hematoxylin and eosin.

Stage 1. — The young oocyte is 10 to 20 n in
diameter and has a large nucleus with a centrally
located nucleolus. The nucleolus and nuclear
membrane stain darkly with the hematoxylin,
whde the cytoplasm and the nucleoplasm stain
with eosin.

Stage 2. — The oocyte, now 20 to 70 p in diameter,
has not yet acquired its follicle-cell envelopment.
The nucleus has grown at a faster rate than the

Table 17. — Sex ratios for mature gizzard shad captured in
the shalloiv waters of Fishery Bay and the deeper waters of
Lake Erie during May, June, and July, 1954 and 1955

Time of capture

Bay

Lake

Male

Female

Males

Male

Female

Males

May:

1-8

Number
1
5
1
5
12

135
142
261
122

660

Number
1
7
2
0
10

52
48
42
82
224

Percent
50.0
41.7
33.3
100.0
45.5

72.2

74.7
86.1
59.8
74.7

37.9

Number
23
29
28

Number
32
44
39

Percent
41.8

9-15

16-23_

39.7
41.8

24-31

1-31

115

41.0

June:
1-8

9-15

16-23

24-30

181

326

84
8

117

247
346

627

170
15
14
5

204

59.0
28.0
34.1

1-30

34.2

July:

1-8

33.1

9-15 ... .

34.8

16-23

62.2

24-31

28.6

1-31

37.9

36.4

cytoplasm. This cytoplasm is now accepting
some of the hematoxylin, while the ground sub-
stance of the nucleus still stains with eosin. The
nucleolus, if present, is lost among the darkly
staining chromatin materials which are somewhat
scattered throughout the nucleus.

Stage 3. — This stage includes oocytes which
range from 0.07 mm. to 0.15 mm. in diameter.
The nucleus and cytoplasm appear to have grown
at the same rate from the last stage. The cyto-
plasm now stains darkly with hematoxylin; the
nuclear sap stains pink. The dark- staining chro-
matin material is more plentiful and is arranged
circumferentially along the periphery of the
nucleus. Flat follicle cells are arranged as a
single-celled layer around the oocyte.

Stage 4- — The follicle is mostly in the 0.15-to
0.30-mm. size range in this stage. The dark-
staining cytoplasm is growing more rapidly than
the nucleus. As the follicle approaches the 0.30-

GIZZARD SHAD IN WESTERN LAKE ERIE

409

*&?

Figure 11. — Growth and maturation of gizzard shad eggs.

mm. size, the oocyte's cytoplasm is stained by
both hematoxylin and eosin — the resulting red-
dish-purple oocyte is clearly noticeable among the
bluish-purple smaller oocytes. The nuclear mem-
brane and chromatin material surrounding the
pink-staining nucleoplasm appear fuzzy as though
disintegrating. Oil globules have formed in the

periphery of the cytoplasm beneath the follicle
cells that have become cuboidal.

Stage 5. — In this stage the oocyte with its
envelope of follicle cells — now columnar — grows
from 0.30 mm. to about 0.45 nun. The nuclear
membrane has largely disintegrated, and chro-
matin material has all but lost its discreteness.

410

U.S. FISH AND WILDLIFE SERVICE

The peripherally formed oil globules have become
larger and are moving toward the nuclear area.
Small yolk granules have appeared, some of which
have encroached upon the nuclear area, making
this area smaller than it was in the preceding
stage. These yolk granules stain mostly with
eosin, while the cytoplasmic ground substance
stains with both dyes. A homogeneous vitelline
membrane has made its appearance between the
oocyte and its surrounding follicle layer.

Stage 6. — During this stage the follicle size is
between 0.45 mm. and 0.50 mm. The nuclear
membrane and chromatin material are no longer
evident; the oil globules have migrated around
the nuclear area and encroached upon it so that
the area now is relatively small. During this
migration, the yolk granules have moved away
from the central area, leaving this area surrounded
by oil globules. The small yolk granules of the
previous stage have now become very coarse.
The vitelline membrane under the single-celled
follicle layer is now thick and prominent.

Up to this stage the oocyte appeared to be
isolecithal since the nucleus occupied a central
position as long as it was evident and the amount
of jTolk compared with the size of the nucleus did
not seem to be plentiful. Just prior to spawning,
however, the oil globules almost completely dis-
appear and the cell is so packed with large yolk
granules that no definite nuclear region is recog-
nizable. The tremendous amount of yolk, despite
the lack of information regarding the location of
the nucleus, suggests that the oocyte now is
telolecithal.

Before the egg leaves the ovary, the single-celled
follicular layer ruptures and separates from the
vitelline membrane. The former remains in the
ovary where it gradually disintegrates. The
vitelline membrane becomes greatly distended by
imbibed water after the egg is spawned and
water-hardened.

Most of the O-group gizzard shad already had
oocytes in Stages 1 and 2 as early as October.
After they appeared, they were a constant feature
in the ovary; they were most abundant in the fall
in O-group fish, somewhat less abundant in older
fish immediately after spawning, and least plentiful
in ripe fish. In the O-group shad the oocytes
begin development so late in the season that
usually they do not progress beyond Stage 2 by
late fall; there is an accumulation of Stages 1 and

2. Older shad which spawned, however, showed
no such accumulation, for the oocytes that
formed earliest had time to progress to later stages.
Their constant presence — though they are not
plentiful in near-ripe and ripe fish — indicates
that one or both of the following processes must
occur: these early stages are continually being
formed, perhaps at varying rates; or the oocytes
formed later in the generative season — if there
be one — remained more or less dormant throughout
the remainder of the season — the nutrients being
diverted to the earlier formed, more advanced
oocytes.

In shad which had spawned, oocytes in Stages
3 and 4 are found in late fall and winter, but in
the youngest shad (I group after January) they
appear in spring.

Stages 5 and G usually do not appear in the
I-group fish; they are present in spring in the
II-group shad, and are found in spring and early
summer in the older females.

SEASONAL CHANGES IN THE OVARY

The seasonal changes in the ovary of every
gizzard shad are much the same after the first
spawning, which occurs usually in II-group fish.
Changes preliminary to first spawning follow a
different course.

During fall, the oocytes of O-group fish appear
late and progress so slowly that by the time the
spawning season arrives (fish are now I-group)
the eggs are not mature enough to be spawned.
In a few fish of this age (presumably those which
hatched very early) some of the eggs become
mature and are spawned late in the spawning
season (fig. 10). In a few others, the eggs become
mature too late to be spawned and are resorbed
(fig. 12). In most of these I-group fish, however,
most of the eggs have developed to Stage 4
(fig. 11), and remain at that stage until the next
spawning season approaches.

For convenience, the ovarian changes of gizzard
shad after their first spawning have been divided
into six stages (fig. 13).

Stage A. — In late July, August, and early
September, the shrunken ovary is filled with
oocytes in Stages 1, 2, and 3. The germinal
epithelium extends inward from the periphery
of the ovary in irregular layers. The central
cavity of the saccular ovary is highly variable and

GIZZARD SHAD IN WESTERN LAKE ERIE

411

is much branched. The branches extend between
the layers of the germinal epithelium.

Stage B. — From late September to early Novem-
ber the ovary contains a greater proportion of
oocytes in Stage 3 than earlier in the season.
Some oocytes of Stage 4 are also present.

Stage C. — During winter and early spring the
ovary contains some oocytes in Stage 5, a great
many in Stage 4, and decreasing numbers in the
earlier stages.

Stage D. — In April, May, and early June the
ovary has oocytes mostly in Stages 5 and 6;
those in Stage 6 become more and more pre-
dominant toward the close of this period. Some
oocytes in Stages 1 and 2 also are present. Those
in Stages 3 and 4 are rare. The central cavity of
the ovary is obliterated by the dense packing of
the large oocytes.

Stage E. — In June, the eggs in the ovary are
in a stage subsequent to the last stage shown in
figure 11 — some are ready to be spawned. That
others have left the ovary is apparent from the
empty spaces and the follicular remnants. Oocytes
in Stages 1 and 2 are present — a few in Stages 5
and 6 may still be found.

Stage F. — Immediately after spawning and
perhaps for a week or two later the ovary contains
remnants of the old follicular layers. The oocytes
present are mostly in Stages 1 and 2, but some
have already reached Stage 3.

The seasonal progression of ovarian change by
no means proceeds at the same rate in all gizzard
shad. The figures represent the situation for
most shad in western Lake Erie. In some of the

O .D^fe*1

Figure 12. — Unspawned eggs being absorbed while new
eggs are developing (I-group gizzard shad, December 16,
1953).

fish the stages are months in advance of those
given in the figure; in others, they are months
tardy. Nevertheless, differences among indi-
viduals decrease as the spawning season ap-
proaches. Fish with advanced rates exhibit
slower development just prior to the spawning
season, but development proceeds rapidly in
fish with retarded rates.

Fecundity

The number of eggs per individual varied
considerably (table 18). Although the number
of counts is meager, the averages for the age
groups definitely show low egg production among
the precocious I-group shad, a maximum pro-
duction by the II-group fish, and slowly declining
numbers among successively older age groups.

Table 18 — Number of eggs per individual gizzard shad of different sizes and ages

Age and date of capture

Standard
length

Weight

Ovary
weight

Estimated
eggs per fish

Eggs per
gram of fish

Eggs per
gram of
ovary

Ovary as

percentage of

fish weight

Age group I:

July 6, 1954

Mm.
225
236
231

282
285
292
293
305
291

322
328
343
331

348
363
356

355

260
305
283

524
529
593
578
526
550

713
700
847
753

882
895
889

1,114

3.9

14.8
9.4

78.6
71.7
35.2
24.6
55.8
53.2

44.5
62.6
36.2
47.8

28.8
74.2
51.5

29.8

Number
22, 400
96,560
59, 480

543, 910
524, 580
211,380
258,350
356, 710
378, 990

406, 170
367. 670
260, 510
344, 780

267, 220
350,280
308, 750

215, 330

Number
86
317
210

1,038
992
356
447
678
689

570
525
308
458

303
391
347

193

Number
5,744
6,524

6, 328

6,920
7,316
6,005
10. 502
6.393
7, 124

9,128
5,873
7,196

7, 213

9,278
4, 721
5,995

7,226

Percent

1.5

July 8, 1954

4.8

3.3

Age group II:

May 23, 1955

15.0

June 3, 1954

13.6

May 20, 1954

5.9

May 20, 1954

4.3

May 23, 1955

10.6

9.7

Age group III:

May 23, 1955

6.2

June 18, 1954

8.9

June 24, 1954

4.3

6.4

Age group IV:

June 18, 1954

3.3

June 23, 1954

8.3

5.7

Age group VI:

June 23, 1954

2.7

412

U.S. F]

SH AND

Wildlife

SERVICE

As the fish become older, their ovaries acquire
increasing amounts of connective tissue; hence,
they should produce fewer eggs per gram of ovary
with increase in age. This anticipated change is
not borne out, however, in table 18. The per-
gram-ovary yield of eggs was highly variable,
even among the fish of an age group. The situa-
tion is not surprising since the problem of finding
differences is compounded by the fact that the
ovaries were hi varying stages of development at
the time the fish were captured. An ovary con-
tains a certain number of eggs which would be
coming spawning season,
with immature ones and
the ovary, make up the
The farther along these

spawned during the
These eggs, together
other components of
weight of the ovary.

eggs develop the heavier they become; the weight
of the ovary increases and its per-gram yield of
eggs decreases.

On the per-gram-ol-fish basis the older fish do,
indeed, produce fewer eggs than the younger ones
(except the precocious I group). The "relative
fecundity" tripled from the I group to the II
group and then declined to age-group VI which
had about the same value as the I group.

On the basis of fish size it would appear that
fish weighing 500-600 g. produce more eggs than
do those whose weights fall either below or above
that range. The productivity of these fish may
be the result of age rather than size, however;
in the table only the II-group shad occupy this
range. Further information on this possibility
was gained from 69 II-group female shad, captured
in the first two quarters of June 1954; their weights
ranged from 339 to 733 g. They were divided
by 50-g. groupings (301 to 350, 351 to 400, — ),
and the ntio ol ovary weight to fish weight was
calculated for each group. (Egg counts had not
been made on these fish.) The ratio was highest
for the 500- to 600-g. fish. This finding would
suggest, then, that fish in this weight range
produce the most eggs.

Spawning

The single spawning site of gizzard shad that
I was able to find was a bar some 200 feet long
and covered by 2 to 4 feet of water near Put-in-Bay.
The bottom is topped with sand, gravel, and
boulders. Cladophora, Myriophyllum, and Bu-
tomus umbellatus (forma vallisneriifoluis) are abun-
dant during the spawning season.

No gizzard shad were found on this bar in 1954
prior to, or after, the spawning season. To learn
the day-to-day variations of the numbers of shad
there during the 1955 spawning season, I set a
100-foot, 4-inch-mesh gill net nightly along the top
of the bar from May 9 to June 30. The catches,
together with the water temperatures, are recorded
in table 19.

It was evident later that the female shad does
not spawn her entire egg holdings in one visit to
the bar. Consequently, some shad would prob-
ably have visited the bar more than once during
the season had they not been caught. Further-
more, gizzard shad exhibit greater activity at the
height of spawning than just prior to it or after-
wards. Hence, greater percentages of those
present in a given area are likely to swim afoul
of the net at this tune than at other periods. The
table must be interpreted with these points in
mind.

Temperature clearly is important in the onset
and progress of spawning. Gizzard shad first
appeared in the net on this bar at a temperature
of 59° F. and were common at about 67° F.
Indeed, when the water temperature dropped
slightly (to 65° and 65.5° F. on June 12-15) the
numbers of shad also dropped.

To define the spawning site more precisely, I
set gill nets transversely across the bar. In every

Table 19. — Water temperatures and daily captures of shad
by a 100-foot, 4-ineh-mesh gill net set on a spawning site
in Fishery Bay in May and June 1955

[The net was lifted daily at 9 a.m. except on June 2-11 (see text); the water
temperature was read at the time of lifting)

Date

Shad
caught

Water
tempera-
ture

Date

Shad
caught

Water
tempera-
ture

May 10

Number

° F.
58.0
59.0
58.5
60.0
60.0
59.0
61.5
59.5
59.0
59.0
60.0
61.0
61.0
61.0
61.0
61.6
61.0
62.5
63.0
63.0
62.0
63.0
64.0
65.5
67.0
66.0

June 5 —
6_.__
7... .
8....
9....

10.-.

11....

12....

13....

14....

15....

16....

17.—

18....

19....

20....

21.—

22— _

23.—

24....

25....

26....

27—.

28....

29....

30—-

Number

° F.
66.0

67.5

66.5

65.5

66.5

66.0

17. .

65.5

65.0

65.5
65.5

68.0

70.0

71.0

71.5

72.0

71.0

71.5

72.0

72.5
73.0

73.0

June 1

2
3
4

6
20
10

74.0
73.5
73.5
73.0

GIZZARD SHAD IN WESTERN LAKE ERIE

413

Figure 13. — Six stages in the seasonal changes in the ovary of gizzard shad.

lift most of the gizzard shad were caught in that
portion of the net that crossed the highest area of
the bar, and fewer at the ends of the nets where
they sloped gradually into deeper water.

The conditions described here must not be
taken as the only ones under which gizzard shad
may spawn. Although 1 have little information

on possible shad spawning in the lake, and have
never taken shad eggs in plankton nets in the open
lake, gill nets and trap nets sometimes have had
eggs of gizzard shad and other fish adhering to
them during the spawning season. The females
may have forced spawn from themselves during
their attempts to escape from the gill nets or they

414

U.S. FISH AND WILDLIFE SERVICE

may have been held beyond their spawning time
in the trap nets, which were lifted only every
other day.

It is also probable that some gizzard shad are
not able to find a suitable spawning site by the
time the eggs are ready to be expelled. This
possibility is supported by the observation that
some of the female shad caught in the lake by
commercial fishermen were releasing eggs. To
explore this possibility further, I determined the
percentage of spawning fish for the II-group and
older female shad caught in Fishery Bay and for
those captured in the lake during May, June, and
July 1954-55 (table 20). The state of the ovaries
was determined by gross examinations. The
much smaller percentages of spawning shad cap-
tured in the lake than in the bay suggest that most
of the ripe females migrated from deeper to shal-
lower water during the spawning season. This
finding is not in disagreement with the earlier
observation (tables 16 and 17) that the percentage
of females in June was less in the shoal water than
in the deeper water. The high percentage of males
on the spawning reef can be explained on one
or more of the logical assumptions that: greater
numbers of males than females entered the shoal
area from the lake; that activity was greater
among the males than among the females in the
shoal waters; that males individually stayed longer
on the site.

When fish begin to spawn, the rise in the
"spawning" category should coincide with the
drop in the "nonspawning" category if the fish
do not migrate from the area. Lack of this rela-

tion in the lake provides further evidence that
most of the fish do not remain in the deeper water
when they are ready to spawn.

The rapid rise of the "spent" category in the
lake from mid-June through July, which is com-
pletely out of proportion with the drop in the
"spawning" group there, indicates a return of the
spent fish from shallow water to the open lake.

The data of table 20 on the percentages of non-
spawning, spawning, and spent females captured
in Fishery Bay and in the lake during May,
June, and July 1954-55 also give a basis for the
estimation of the beginning, peak, and end of the
spawning season of II-group and older shad.

The earliest samples containing spawning fish
were captured in the first quarter of June on the
spawning bar in Fishery Bay. The percentage
of spawners caught here rose from 33.3 percent
in that quarter to a high of 58.3 percent in the
next quarter, then dropped to 45.0 percent in the
third quarter and abruptly to 1.2 percent in the
last quarter of June. Spawning shad were
captured from the first quarter of June to the
first quarter of July inclusive.

Although I lacked samples from the lake in the
first quarter of June (the commercial fishermen
of South Bass Island — the source of the lake-
caught gizzard shad — did not fish during the last
quarter of May and the first quarter of June)
the Fishery Bay sample for that quarter and sub-
sequent samples from the lake lead me to assume
that spawning fish, though never numerous, were
present here at that time also.

Spent fish were first observed in the first quarter

Table 20. — State of ovaries of mature II-group and older gizzard shad captured in Fishery Bay and in Lake Erie in May,

June, and July 1954-55

[Given as percentages of fish in the categories "not spawning," "spawning," and "spent"]

Bay

Lake

Time of capture

Females

Not
spawning

Spawning

Spent

Females

Not
spawning

Spawning

Spent

May:'
1-8.

Number
1
7
2

51
48
40
82

95
1
2

Percent
100.0
100.0
100.0

64.7
37.5
30.0
30.5

33.6

100.0
100.0

Percent
0.0
.0
.0

33.3

58.3

45.0

1.2

7.4
.0
.0

Percent
0.0
.0
.0

2.0

4.2

25.0

68.3

59.0

.0
.0

Number
32
44
39

Percent
100.0
100.0
100.0

Percent
0.0
.0
.0

Percent
0.0

9-15

16-23

June:
1-8

9-15

208
322

170
15
14
5

85.3
78.8
44.4

38.8

33.3

8.8
2.4
3.1

4.7
.0
.0
.0

5.9

16-23..

24-30..

18.8
52.5

July:

1-8

56.5

9-15

66.7

16-23 . .

100.0

24-31

100.0

' No females captured May 24-31.
GIZZARD SHAD IN WESTERN LAKE ERIE

415

of June in the Fishery Bay samples. Thereafter,
all samples from both bay and lake showed in-
creasing percentages of spent shad during June.
In July, this trend persisted among the lake
samples, but in the bay samples both spawning
and spent fish were absent after the first quarter
and only three nonspawning ones were captured.
The available data indicate that the gizzard shad
in western Lake Erie spawn during June and early
July; the greatest percentage of them spawn in
the second quarter of June.

Records of the average ovary weight as a
percentage of the fish weight, for II-group and
older female shad in 1954-55 (table 21), indicate
that the ovary makes little increase in weight
from the time the fish are spent until the following
April. During that month, feeding increases (this
is the first time in winter or spring during which
recognizable food has been found in the shad's
gut — -table 24), but the fish weight decreases
(table 9). Consequently, the combination of a
little ovarian growth and loss of fish weight
results in a rise in the ovary-weight/fish-weight
ratio. This ratio is highest either in the last
quarter of May, for which I have no samples, or
the first quarter of June. In this period, more
fish are just ready to spawn and fewer are spawning
or are spent than at any subsequent period. Then,
as more fish become partly or completely spent,
the average ratio drops lower. The drop in
June is steady, and in the last quarter of that
month the ovary weight as a percentage of body
weight is again at about the April level. I have
no ovary weights for July, August, and September.
However, since some shad are still spawning in

Table 21. — The percentage of fish in the categories "not
spawning", "spawning", and "spent", and the ovary
weight as a percentage of the fish weight for I I-group and
older female gizzard shad, Lake Erie, 1954-55

Period

Oct _.

Nov

Dec

Jan —

Feb

March

Apr. ..
May 1-8..-.
May 9-15. . .
May 16-23 i
June 1 8
Iir i' y-15. .
.Tune 16-23.
June 24-30.

Fish

Not
spawning

Spawning

Spent

Number

Percent

100.0

0.0

100.0

102

100.0

100. 0

100.0

64.7

33.3

•-'. 11

58.0

37.0

5.0

113

47.8

16.8

35.4

102

16.7

82.4

Ovary/fish
weight

Percent
1.1
.9
1.5
1.1
1.8
1.5
2.4
3.8
4.2
4.3
9.9
8.5
5.3
2.5

i No samples May 24-31.

416

July and follicular remains were yet to be absorbed,
I suspect the low percentage of winter samples
is not reached earlier than the last of July.

The mature I-group gizzard shad spawn later
than older fish. Ova of three fish captured
during the 1954 spawning season (June 28, July 6,
and July 8) were nearly ripe (fig. 10). These
fish probably would have spawned in late July
or early August, or else the ova would have been
resorbed.

The eggs of the II-group fish which have been
in the making for \% to 2 years — much longer
than those of older fish — might be expected to be
spawned earlier than those of older fish. Infor-
mation on the older shad is too scanty, however,
to permit study of this possibility.

The weight of the fish appeared to have no
effect on the time of its spawning.

I tried two methods to determine the time of
spawning within a 24-hour period. In one, a gill
net was set on the previously mentioned spawning
bar in the afternoon, lifted at midnight, reset
immediately, lifted in the morning, reset again,
and lifted in the afternoon. The numbers of
shad of each sex were tabulated for each period.
In the other method, concrete slabs with a surface
area of 1 square foot were lowered to the bottom
at the spawning site and examined for shad eggs
three times daily, when the gill net was lifted.

Studies by the two procedures covered only 3
days, June 17-19, 1954; in 1955, the net method
alone was employed (June 2-11). The gizzard
shad spawned most actively in the evening and
early night in 1954 and at night in 1955 (table 22) ;
spawning was least in the daytime in both years.
I have not seen shad spawning during the day-
time, but have seen them milling actively, fre-
quently breaking surface, when I lifted the net
at midnight, especially in moonlight.

The individuals participating in' the spawning
change continually during the season, but a female
does not deposit all her eggs during one nightly
visit to the bar. Although the percentage of eggs
remaining in the ovaries varies among individual
fish throughout most of the spawning season,
numerous partially spent fish with a substantial
percentage of eggs still in the ovary are taken
early in the season. Almost none carry large
percentages of their eggs toward the close of the
season. The state of development of the "nearly
mature" ova and the free ones in the ovaries of

U.S. FISH AND WILDLIFE SERVICE

Table 22 1 — Shad eggs and the spawning condition of gizzard the site j d() t b y fch avoided the gear,

s/ma collected during various periods of the day on a spawn- J «"«* »"" &^»* »

ing srte near Put-in-Ray, Ohio, in June 1954 and 1955 because the nets were treated with a copper

preservative that rendered them greenish and,

hence, less visible than untreated nets, and were

set in aquatic vegetation which almost wholly

obscured them. White bass, smallmouth bass,

and rock bass, but very few gizzard shad, were

caught in the day.

During the midnight lifts, however, when the

moon shone brightly, I saw many fish swirling

and breaking water. The moonlight was not

bright enough for me to judge accurately the

species or size. The gill nets caught many gizzard

shad, however, during those nights and had many

shad eggs adhering to the webbing. The only other

spawning gizzard shad indicates possible periods fish caught at those times were a few carp.

Fish taken by gill nets

Dates and period of day

Males

Females

Eggs on
concrete
slabs i

Not yet
spawned

Partly
spent

June 17-19, 1954:

6:30 a.m.-7:30p.m

7:30 p.m.-12 p.m

12 p.m.-6:30a.m._ ..

June 2-11, 1955:

Number
0
91
50

48
70

Number
2
16

0
4
6

Number
1

19
14

7
9

Number
2
15
5

4 p.m.-12 p.m

12 p.m.-9 a.m

i No observations in 1955.

of rest between spawnings.

The males captured on the spawning site during
the period of most active spawning outnumbered
the females three to one. This abundance of
males may be attributed to one or more of the
following: Their actual daily recruitment to the
spawning site, their probable greater activity,
or their possible longer stay on the site. I was
unable to distinguish any degrees of "spentness"
in the male.

Not having observed details of behavior of
spawning gizzard shad, I can offer only the
statements of others on spawning behavior.
Langlois (1954) observed gizzard shad spawning
on May 29, 1935, in North Reservoir at Akron,
Ohio, near shore in 6 to 12 inches of water at a
water temperature of 67° F. During oviposition,
a female was flanked by a male on each side.
No time of day was indicated. M. B. Trautman
(personal communication) observed about 20
shad spawning in Buckeye Lake, Ohio, at 73° F.
on May 23, 1939. The females, pursued by
several males, swam rapidly toward a sloping
stone wall, turned abruptly, and deposited their
eggs. A. G. McQuate (personal communication)
observed shad spawning in Sandusky Bay, Ohio,
on May 24, 1954 (temperature 62.5° F.), along a
stony shore near 12 m. (noon) in the shade of an
overhanging tree. Female shad were pursued by
several males. The fish frequently broke water.

My own failure to see gizzard shad spawning
during the daytime at the spawning site in Fishery
Bay can be attributed to their failure to spawn at
that time. The small daytime catches in gill
nets suggest that shad were extremely scarce at

GIZZARD SHAD IN WESTERN LAKE ERIE
774-711 O— 66 9

Hatching and Early Development

The eggs of the gizzard shad are heavier than
water and slowly sink after they are spawned.
The egg capsules adhere to surfaces that they
contact, such as submerged aquatic plants and
stones. Experiments in the Ohio State Hatchery
at Put-in-Bay indicated that the hatching time
varies from about 36 hours to about a week,
depending on the temperature. This finding
agrees with Warner's 2 observations at Buckeye
Lake, Ohio.

In a series of experimental hatchings over 2
seasons, I failed to keep the young alive beyond
the 10th day after hatching. Mortality was low
up to the 9th day and the fish appeared to be
doing well; then suddenly on the 10th day only
a few remained alive out of thousands. The
remainder died before the day ended. Results
were the same in running and aerated water and
with various kinds of food, such as natural food
from the lake and cultured protozoans.

The movements of the newly hatched gizzard
shad were an upward swimming and a downward
settling — in each direction the head was foremost.
This behavior continued 3-4 days. The whole
body moved sinuously with such rapidity that the
individual movements could not be followed. At
this time the pectoral fins were not yet used to
any extent. On the fourth day the fry began to
swim horizontally as well as upward and down-
ward. Their mode of swimming at this age,

2 Warner, E. N. 1940. Studies on the embryology and early life history
of the gizzard shad, Dorosoma cepedianum LeSueur. Doctoral thesis, Ohio
State University. (Unpublished.)

417

observed (in a petri dish) under a dissecting micro-
scope, was largely by the pectoral fins which
"vibrated" seemingly with the rapidity of the
wings of a bee in flight. The sinuous body move-
ment was not abandoned, but the frequency had
slowed enough that it could be followed easily.

When food was added to the aquarium, the
young shad darted to and fro as though pursuing
some of the small particles. Although the di-
gestive tract contained food during the fifth or
sixth day, only green algae were recognized
through the thin gut wall.

The young shad congregated on the lighted
side of the aquarium. If all sides were lighted,
they remained mostly near the source of the
running water, facing into the current.

The first few days after hatching, the young
gizzard shad subsists on its yolk. Increase in
length of the 3.5 mm. newly hatched larva at
this time results largely from the straightening of
the cephalic flexures, after which the larva attains
a length slightly greater than 5 mm. About the

5th day it begins to feed and by the 10th day has
attained a length of slightly more than 6 mm.
(in the laboratory). At this time it has a filiform
shape, which it retains until it has reached a
length of 20-30 mm. (fish from the lake — age
unknown). Upon reaching this length, the shad
begins to increase in depth. The filiform shape
gives way to the slab-sided, deep-bodied adult
form. Once this shape is acquired the form
changes little and the shad begins to grow rapidly.

DIGESTIVE TRACT

Development of the Digestive Tract

The gut of a newly hatched gizzard shad is a
tube which conforms to the body curvature. In
the 10-day-old larva the gut is a simple, nearly
straight tube. Among the older shad the gut of an
18-mm. fish (age unknown) had already developed
two flexures (fig. 14). The 19-mm. shad had
begun the third and fourth flexures, and the 22.5-
mm. fry had already completed them. The portion

ii - - ■ --*— *

18 MM. SHAD (SL)

19 MM. SHAD (SL)

33 MM. SHAD (SL)

22.5 MM. SHAD (SL)

27.5 MM. SHAD (SL)

51 MM. SHAD (SL)
Figure 14. — Development of the shad gut (camera lucida drawings).

418

U.S. FISH AND WILDLIFE SERVICE

between the first and second flexures (later to
become the gizzard) had enlarged. By the
27.5-mm. stage, the caeca had begun to develop
from the duodenum (between the second and third
flexures). As the gut continues to grow, the
flexures move until they reach the limit of the
abdominal cavity. Since the gut grows much
faster in length than the abdominal cavity,
secondary flexures are produced between the
primary ones. Flexures provide landmarks by
means of which one can determine relative rates of
growth of the different portions of the gut. The
caudal portion grows more rapidly and continues to
grow over a longer period than any other section.
No secondary flexures develop anterior to the
third primary one.

Although the course of the gut of a young giz-
zard shad is complicated, it is relatively simple in
comparison with that of the adult of, say, 250 mm.,
in which the convolutions are so numerous and
complex that they defy tracing on a two-dimen-
sional illustration. Indeed, the gut which amounted
to one-half of the total length of the day-old
fish becomes, in the adult, three times the length
of the fish and is packed in an abdominal cavity,
one-third of the fish's length.

Forbes (1914) stated that the larva of the gizzard
shad has teeth. Although I have examined many
young, from newly hatched to longer than 20 mm.
(when the adult shape begins to take form), I have
not observed teeth.

Digestive Tract in the Adult

The hundreds of long, thin gill rakers of the
gizzard shad are admirably adapted for removing
particulate matter from the water. This ma-
terial, especially the filamentous algae and the
small crustaceans, apparently is accumulated in
the pharyngeal pockets, a paired muscular organ
mentioned by Forbes (1888) and described by
Lagler and Kraatz (1944). The thick muscular
wall and the direct connection with the esophagus
suggest that these pharyngeal pouches force their
contents into the esophagus. The sphincter
muscles in the forepart of the pneumatic duct
prevent passage of food into the air bladder.

The muscular esophagus and the gizzard have
been described by Wier and Churchill (1945).
I can add only that the esophagus possesses
longitudinal folds.

Numerous caeca arise in groups on the lateral

GIZZARD SHAD IN WESTERN LAKE ERIE

surface of the duodenum. Each group has a
common orifice through which the lumina of its
caeca communicate with the lumen of the duo-
denum. These orifices are arranged in two parallel
longitudinal rows. In a 200-mm. shad the lengths
of the caeca range from about 5 mm. for those at
the anterior end of the row to about 2 mm. at the
posterior end. Counts were not made, but an
individual appears to possess several hundred
caeca. The caeca have internal longitudinal folds.
Their lumina are so small that only the smaller
unicellular organisms can enter. Although the
caeca have the histological appearance of absorp-
tive devices rather than secretory organs, it is only
when the duodenum is turgid with food that any
material is to be found here.

Wier and Churchill (1945) described a pancreas
separate from the liver for the gizzard shad. I have
been unable to identify one although I have
searched for it repeatedly in many sizes of fish.
These authors described the liver as composed of
several lobes. I find that it has no definite form
in the adult fish but rather seems to spread in close
proximity to the gut. The liver invades inter-
caecal spaces as well as those between neighboring
portions of the gut, and completely covers the
anterior, dorsal, ventral, and left-lateral surfaces
of the gizzard. It is a diffuse organ and intermixed,
I believe, with the pancreas.

The small intestine possesses no villi, contrary
to the statement of Forbes and Richardson
(1908). It does contain four of the large, con-
spicuous, longitudinal folds described by Wier and
Churchill (1945). Attached transversely between
the folds and along the inner circumference of the
gut are smaller folds or lamellae which have the
free edge directed toward the center of the gut
lumen (fig. 15). The free edge of each lamella
is directed posteriorly at a slight angle. Although
the columnar cell covering of these transverse
lamellae is unquestionably absorptive and these
structures greatly increase the absorptive surface
of the gut, they may also function in the manner
suggested to me by Milton B. Trautman. He
suggested that during peristalsis the longitudinal
ridges may lengthen and shorten, thereby causing
the lamellae to move back and forth in venetian-
blind fashion and, hence, to aid in forcing food
along the tract.

This lamellar arrangement within the gut bears
some resemblance to the situation described by

419

Figure 15. — Enlarged view of the small intestine of the
gizzard shad showing three of the longitudinal folds with
their transverse lamellae.

Kraatz (1924) for the gut of Campostoma ano-
malum in which somewhat similar folds assume a
zigzag arrangement.

Transverse lamellae were present in a 22.5-mm.
shad. Here they were attached circumferentially
to the gut only — the longitudinal folds had not
yet formed.

Longitudinal sections of the gut, because they
cut across the lamellae, appear to be villous. This
fact may account for the statement of Forbes and
Richardson that the gut possesses villi.

Digestive Enzymes

Only a qualitative study was made of the diges-
tive enzymes. Attempts to determine their quan-
tity or potency did not yield dependably accurate
results. The areas tested were: Pharyngeal
pockets, esophagus, gizzard, duodenum (that
forepart of the gut bearing the caeca), hepato-

pancreas, gall bladder, and the first, second, and
third portions of the intestine. The materials
were prepared in the usual manner and the extrac-
tion made with 50 percent glycerol.

Tests were made for the following enzymes:
Pepsin, trypsin, amylase, lipase, maltase, sucrase,
and rennin. In addition, I sought enzymes that
would act on chitin and cellulose.

The enzyme giving the strongest reaction was
amylase (table 23). It was present in all areas
tested. The reactions for pepsin and trypsin
were moderate, whereas the reaction for lipase was
weak. I am at a loss to explain the significance of
the positive test for rennin.

The presence of enzymes in the esophagus is not
restricted to the gizzard shad. Sarbahi (1951)
found amylase, maltase, and invertase in the
esophagus of the goldfish, and Kenyon (1925)
cited Kingsley as reporting gastric glands in the
esophagus of the sturgeon.

FOOD AND FEEDING HABITS

The young gizzard shad begins to feed about 4
or 5 days after hatching. The earliest food is
probably Protozoa and unicellular algae. When
the shad has attained a length of about 20 mm.,
it feeds on the smaller of the zooplankters and
takes practically no phytoplankton. By the
time it is 30 mm. long it has assumed the adult
shape, and its gizzard is fairly well developed.
The fish now begins to feed more and more on
phytoplankton.

Three opinions have been offered in the literature
regarding the nature of the food of adult gizzard
shad. Some believe they eat predominately mud ;
others insist that they feed almost wholly on

Table 23. — Digestive enzymes found in the gizzard shad
(I( no value is given, a test was not made. The numerical ratings are: 0, negative; 1, not definite; 2, perceptible; 3, small; 4, considerable; 5, strong]

Area tested

Enzyme

Pharyngeal
pockets

Esophagus

Gizzard

Duodenum

Intestine

Ilepato-
pancreas

Gall bladder

1st part

2d part

3d part

0
0
3
0
0
0
0
0
0

4
0
3

(1
0
1

0
0

3
4
4
2
1
2
3
0
0

2
3
5
3

1
0
3
1)
0

Trypsin.

0
0
0
0
0
0

0
0
0

4
0
0
0

3
0
0
0

Rennin

0
0

420

U.S. FISH AND WILDLIFE SERVICE

Table 24. — Monthly record of occurrence of various items in stomach contents of gizzard shad in 1952-55

Material in digestive tract

Month

Debris

Sand

Diatoms

Dino-
flagcl-
lates

Blue-
green
algae

Green
algae

Proto-
zoans

Rotifers

Ostra-
cods

Cope-
pods

Cladoc-
erans

Insect
larvae

•X

Feb

X
X
•X
•X

*x
x

X
X

*x
»x

•X

X
•X

X
X
•X

•X
•X

•X

May

•X

•X
X

X
X
X

•X
•X
•X
X
X
X

*X
•X
•X
X
X
X

July. .

X
X

*X
•X

X
X

Sept

Oct

Dec

'Indicates the more plentiful items.

phytoplankton; still others maintain that they
subsist mostly on zooplankton. All agree, how-
ever, that they are "filter-feeders," and this
feature alone, I believe, best describes their
feeding habits. They filter the water of whatever
particulate matter it contains. Shad captured in
open waters contained mostly free-floating phyto-
plankton; those captured among the attached
plants, such as Cladophora, Myriophyllum, and
Ceratophyllum, ingested Cladocera, Copepoda,
Rotifera, and small aquatic insect larvae; those
captured in very turbid waters were filled largely
with mud. That they do, however, add to their
diet from the bottom debris is evidenced by the
presence in the gizzard of sand particles of di-
ameters in excess of 0.25 mm. This size of sand
is not held in suspension even when the water
is highly turbid. Although the bottom is available
to the shad at all times, I have not found sand
in shad gizzards from December through March.
Food particles could not be identified during
this period. The taking of sand when food is
plentiful suggests its use as an aid in grinding
by the gizzard — or it may have been taken
accidentally along with food.

The appearance of the food differs in the three
distinct regions of the alimentary apparatus —
the pharyngeal pockets, the gizzard, and the
intestine (especially the forepart which bears
caeca and which is often swollen with ingested
material). When reference is made to food in
the gizzard shad without regard to a definite
region of the digestive tract, I use the term
"stomach contents."

The pharyngeal pockets, suggested by Lagler
and Kraatz (1944) to be accessory to the digestive

system, have, to my knowledge, not been thor-
oughly examined in studies of food of gizzard
shad. The pouches frequently are empty, but
when food is plentiful and the fish's gut is full
of food (especially zooplankton), the pharyngeal
pockets contain as much food as the gizzard.
The contents of these pockets appear straw-
colored and consist mostly of Cladocera and
Copepoda along with strands of filamentous
algae. Here are found the larger items of the
shad's diet, and they are, as yet, not broken apart.
The zooplankters still have their full complement
of appendages and the filamentous algae are in
strands.

The gizzard is frequently empty, and only
rarely is it turgid with food. The composition of
food in the gizzard is similar to that of the
pharyngeal pockets. The zooplankters, however,
are more or less dismembered, and the strands
of filamentous algae are short. The gizzard
contains, in addition, many unicellular algae,
rotifers, and some sand along with plant and
animal debris.

The intestine usually contains food, although
the amount is scanty in winter. Material from
the intestine is fragmented and mostly unrecog-
nizable— it has the appearance of bottom debris
or mud, especially on gross inspection.

I have found no compact matter exceeding a
diameter of 3 mm. in the stomach contents of
gizzard shad, except Tendipedidae and small
Leptodora during certain seasons. Nor have I
found in them bits of attached aquatic plants,
except after severe storms when small fragments
were presumably torn loose and were recovered
by the filtering apparatus.

GIZZARD SHAD IN WESTERN LAKE ERIE

421

The stomach contents of adult gizzard shad
exhibited no appreciable differences among indi-
vidual shad of a group collected in a locality at
the same time. Evidence was lacking for any
selection of food within the size range of material
they swallow. There were, however, local and
seasonal differences related, undoubtedly, to the
abundance of the various forms in different places
and at different times. As a result of these ob-
servations, examination of stomachs of individual
fish was soon discontinued and the stomach con-
tents of several fish of a collection were combined.

The feeding habits of gizzard shad were well
summarized by Tiffany (1920) who indicated
them to be a living tow net. No attempt was
made in the present study either to obtain the
percentage of each item ingested or to enumerate
every organism eaten by the shad at one time or
another. In table 24 are listed only major groups
of materials found in shad during various months.
The table does not identify the months in which
the gut contained the most food; in general, the
quantity was more plentiful when the diet con-
sisted of a great variety of food in June through
November.

Velasquez (1939) cultured algae taken from
various parts of the shad gut. As a result either
of rapid transit through the gut, or absence of
certain enzymes, some algae or certain algae
apparently are not utilized as food.

SUMMARY

This study of the life history of the gizzard shad
was based on records of the length, weight, and
age of almost 24,000 specimens taken in western
Lake Erie in 1952-55. Approximate numbers of
fish employed in other phases of the study were:
calculation of growth from scale measurements,
700; seasonal fluctuations of gonad weight, 700;
sex ratio and maturity, almost all fish over 120
mm. long; feeding habits, 200; seasonal develop-
ment of ovaries, 150; and fecundity, 13.

The fish were captured by means of dip nets,
"Common Sense" seines, hag seines, push seine,
gill nets of various mesh sizes, regulation commer-
cial trap nets, and by electric shock, dynamite, and
rotenone. Fish older than the O-group were cap-
tured mostly by the gill nets and trap nets. Most
fish were captured within one-half of a mile of
the Bass Islands.

The scales of the gizzard shad are described
briefly. Two types of annuli are present — a
narrow clear-cut line of demarcation and a wider,
more evident one. The first annulus is always
of the former variety; the second and succeeding
ones (with few exceptions) are of the latter variety.
The wider, obvious annulus may be a combination
of an annulus and a spawning check, whde the
narrow variety is strictly an annulus.

The time of annulus formation varied with age
and sex. Some of the I-group shad began to form
the new annulus in May, and all had it by the end
of the first quarter of June. Annulus formation
of older shad began in June and was completed by
mid-July. Females seem to have formed their
new annulus about a week earlier than the males.
Spawning of these older females occurred while
annulus formation was in progress — some fish
spawned before the appearance of the new
annulus — some after its appearance. Although
prespawning development of the gonads was
thought to affect the physical appearance of the
annulus, the spawning act appeared to have no
effect on the time of its appearance. Evidence
was given that the annulus is a true year mark.

The body-scale relation was a straight line with
an intercept of 22.1 mm. on the axis of standard
length.

Calculated lengths showed good agreement with
empirical lengths of shad captured between the
first of the year and the time of annulus forma-
tion— except for the I group. The greater average
length of I-group fish at capture can be attributed
to gear selectivity.

Sampling problems made the determination of
age composition difficult. The young gizzard
shad were found in shallow water, the older in
deeper water, and the very oldest were captured
only during the spawning season. Shad captured
in the open lake during fall probably gave the best
available estimate of the relative strength of
younger age groups. Those captured during the
spawning season were most nearly representative
of the age composition among the older shad. On
these assumptions the following survival from an
original 100,000 I-group fish were computed:
[I-group, 5,534; Ill-group, 435; IV-group, 63;
V-group, 11: and VT-group, 6.

The 1952 year class was one of more than usual
abundance. In 1953, as I-group they constituted

422

U.S. FISH AND WILDLIFE SERVICK

85 percent of the fish caught; in 1954, 71 percent as
II-group; and in 1955, 11 percent as Ill-group.

Males made up 45.6 to 49.7 percent of the fish
in the four younger age groups (O-III). They
were less abundant (36.6 percent) in the age
groups IV-VI combined. During the spawning
season the percentage of males on the inshore
spawning site was greater than normal but that in
the open lake was less.

The length-weight relation of gizzard shad
varies from year to year, from season to season
within the year, according to sex during the
spawning season, and among the females accord-
ing to the state of the ovaries during the spawning
season.

Equations were derived for length-weight data
and from them was obtained the general length-
weight equation, log \V=— 4.81765 + 3.07053 log
L, in which W is the weight in grams and L the
standard length in mm. Gizzard shad from Lake
Erie were heavier than those reported from Illinois
and Missouri.

Fish of the same length had the. greatest weight
in August-October. Males were lightest in June;
females in May. The spawning-season female
was heavier than the male; this difference in
weight was not traceable to the gonadal develop-
ment in the female, but may result from the
greater activity of the male at this period. Among
the females in the spawning season, those which
would not spawn during the current season were
the heaviest, those approaching spawning were
next, and spent fish were the lightest. The
percentage loss in weight during spawning
averaged 10.7.

Annual differences in shad weight from rela-
tively heaviest to lightest ran: 1952, 1954, 1955,
1953.

Most of the growth in length for the O-group
(which hatched in June) occurred in July-Septem-
ber; for the I-group during June-August; and for
the II-group during July-September. Gizzard
shad of the II-group and older commence their
rapid growth in length about a month later than
the I-group fish. Shad lengths remain practically
stationary from November until the time of
annulus formation.

Males and females had almost the same length
at the end of the first year (140 mm.) but after
about June of the second year of life the females
were consistently longer than males of correspond-

ing ages. The sizes of males and females at the
start of different growing seasons were: third,
males, 273 mm. and females, 285 mm.; fourth,
males, 313 mm. and females, 335 mm.; fifth,
males, 343 mm. and females, 364 mm. ; sixth,
males, 349 mm. and females, 386 mm.

The seasonal growth in weight resembles that of
the growth in length except that weight decreases
during winter while length remains nearly con-
stant. This loss of weight begins about the start
of the year and continues until about May.

Differences among the lengths of individuals of
an age group at the end of a calendar year tend to
be reduced by later compensatory growth. At
the end of succeeding years those fish that were
the longest of their year class maintain a length
advantage, but this advantage decreases.

The stage of egg development varied from fish
to fish throughout most of the year, but with the
approach of the spawning season, the retarded
shad increased their pace of development while
the advanced ones slowed down so that the con-
dition of the ovaries became much more nearly
uniform.

A brief description is given of the testis and of
various stages of the ovary. The developing egg
and the seasonal changes in the saccular ovary
also are described.

Not all mature eggs are expelled at the same
time. Eggs which are not mature are held over
for next year, and those which develop to the
spawning stage too late to be expelled are resorbed.

Only rarely were I-group female shad ripe.
Most of them (an estimated 80 percent) spawn for
the first time as II-group fish. The age of sexual
maturity could not be determined for the male;
males examined in January had motile sperm —
even the new I group. The number of II-group
males on the spawning site suggests that most
mature as the II-group — the few I-group in-
dividuals present may be termed precocious.

A spawning site in the vicinity of Fishery Bay,
South Bass Island, was a sandy, rocky bar covered
with 2-4 feet of water. Gizzard shad were
captured here only during the spawning season —
almost all during the evening and night. Spawn-
ing was limited in the open lake. The females
that are ready to spawn migrate to inshore
spawning sites. After spawning, they return to
the deeper water. Males also migrate to the
spawning sites where they are two or three times

GIZZARD SHAD IN WESTERN LAKE ERIE

423

as numerous as the females. The representation
of the sexes was nearly equal in the open lake at
this time. Spawning was most active in the
evening and early night in 1954 and in the night in
1955.

Spawning occurred from the first quarter of
June through the first quarter of July; peak
spawning was in the second quarter of June.
The precociously mature I-group fish spawn in
late July or later.

The II-group shad produce the greatest number
of eggs — about 379,000. In decreasing order are:
Ill-group, 345,000; IV-group, 309,000; Vl-group,
215,000; and the precocious fishes of the I-group,
59,000.

On the basis of eggs per gram of fish, relative
fecundity triples from age group I to II and then
declines to age group VI, which has about the
same value as the I group.

The eggs of the shad hatch in IK to 7 days,
depending on the temperature. The movements
of young fry are described.

The gut of a small larva is a nearly straight
tube. Sometime after the 10th day the gut
begins to fold. The convolutions become more
and more complex with increasing size. The
gizzard becomes evident in the 22.5-mm. stage.
The liver is a diffuse organ, apparently mixed with
the pancreas; no pancreas was found.

The intestine lacks villi but has longitudinal
folds and transverse lamellae which increase the
absorptive surface and may help move the food
along during peristalsis.

The presence of sand in the gut when ingested
food is plentiful and its absence in winter, when
the gut is empty, suggest that it may be taken as
an aid in grinding the food in the gizzard.

Food was frequently present in the pharyngeal
pockets of large gizzard shad whose gizzard and
intestine were packed with food. The presence
here of long strands of filamentous algae, and
Cladocera and Copepoda with their full comple-
ment of appendages, repudiates statements that
they are regurgitated into the pockets. In the
gizzard, these items were always in some stage
of dismemberment.

Tests were positive for the following digestive
enzymes: pepsin, trypsin, amylase, lipase, and
rennin. Amylase was found in all areas of the
tract.

The earliest food of gizzard shad appears to be

Protozoa. At a length of about 20 mm., shad
feed almost wholly on the smaller of the zoo-
plankters. After the 30-mm. stage, the digestive
tract contains greater and greater percentages of
phytoplankters. "Filter feeders" best describes
the habits of adults. Zooplankters or phyto-
plankters may predominate in the gut according
to their abundance in the water in which the fish
are feeding. By the time the food reaches the
intestine it has been macerated and partially
digested so that it resembles mud. This fact
may explain the frequent statement that shad eat
mud.

ACKNOWLEDGMENTS

I have had the assistance of the staff members
and the students of the Franz Theodore Stone
Institute of Hydrobiology, Ohio State University.
Thomas H. Langlois suggested an investigation of
the gizzard shad in western Lake Erie, made this
investigation possible by arranging an Ohio State
University Senior Conservation Fellowship, and
gave freely of his time in discussing the numerous
problems that arose during the study. N. Wilson
Britt, Milton B. Trautman, Edward C. Kinney,
David Stansbery, and Paul Webster aided in
collecting gizzard shad and made helpful sugges-
tions. Jacob Verduin assisted in graphical repre-
sentations and mathematical interpretations.
Ernest Miller, Superintendent of the Ohio State
Fish Hatchery at Put-in-Bay, made facilities
available for hatching gizzard shad eggs. James
W. Moffett, Director of the Biological Laboratory,
Bureau of Commercial Fisheries, Ann Arbor,
Mich., obtained financial assistance and offered
many helpful suggestions. The commercial fisher-
men— particularly those island fishermen affiliated
with Lay Brothers of Sandusky — brought, in
samples of shad from their nets. Staff members
of District No. 1 , Ohio Natural Resources Depart-
ment, made equipment available. The Ohio
Division of Wildlife, through the Onio State
University, gave financial assistance. Ralph Hile,
Bureau of Commercial Fisheries, Ann Arbor,
Mich., read the original manuscript and offered
suggestions for its improvement.

LITERATURE CITED

Forbes, S. A.

1SSS. Studies of the food of fresh-water fishes.
Bulletin Illinois State Laboratory of Natural
History, vol. 2, pp. 433-473.

424

U.S. FISH AND WILDLIFE SERVICE

Forbes, S. A.

1914. Fresh-water fishes and their ecology. Bulletin
Illinois State Laboratory of Natural History, vol. 10,
p. 4.
Forbes, S. A., and R. E. Richardson.

1908. The fishes of Illinois. Natural History
Survey of Illinois, State Laboratory of Natural
History, vol. 3 (1908), cxxxi+357 pp.
Gerking, Shelby D.

1945. The distribution of the fishes of Indiana.
Investigations Indiana Lakes and Streams, Indiana
Department of Conservation, vol. 3, 137 pp.
Hile, Ralph.

1948. Standardization of methods of expressing
lengths and weights of fish. Transactions of the
American Fisheries Society, vol. 75 (1945), pp.
157-164.
Kenyon, Walter A.

1925. Digestive enzymes in poikilothcnnal verte-
brates. An investigation of enzymes in fishes, with
comparative studies on those of amphibians,
reptiles, and mammals. Bulletin of the U.S.
Bureau of Fisheries, vol. 41, for 1925, pp. 181-200.
(Document 977.)

KlRTLAND, JARED P.

1850. Fishes of Ohio. Fragments of natural history.
Family Visitor, Cleveland [and Hudson], vol. 1,
No. 1, pp. 1-2 (Jan. 3, 1850).
Kraatz, Walter C.

1924. The intestine of the minnow, Campostoyna
anomalum (Rafinesque), with special reference to
the development of its circling. Ohio Journal of
Science, vol. 24, pp. 265-298.
Lagler, Karl F., and Vernon C. Applegate.

1943. Age and growth of the gizzard shad, Dorosoma
cepedianum (Le Sueur), with a discussion of its
value as a buffer and as forage of game fishes.
Investigations Indiana Lakes and Streams, Indiana
Department of Conservation, vol. 2, pp. 99-110,
1942.

Lagler, Karl F., and Walter C. Kraatz.

1944. Pharyngeal pockets in the gizzard shad,
Dorosoma cepedianum (Le Sneur). Papers Michigan
Academy of Science, Arts, and Letters, vol. 30,
pp. 311-320.

Lagler, Karl F., and H. Van Meter.

1950. Abundance and growth of gizzard shad,
Dorosoma cepedianum (Le Sueur), in a small Illinois
lake. Journal of Wildlife Management, vol. 15,
pp. 357-360.
Langlois, Thomas Huxley.

1954. The western end of Lake Erie and its ecology.
J. W. Edwards, Ann Arbor, Mich., 479 pp.
Miller, Robert Rush.

1957. Origin and dispersal of the alewife, Alosa

pseudoharengus, and the gizzard shad, Dorosoma
cepedianum, in the Great Lakes. Transactions ui
the American Fisheries Society, vol. 86 (1956),
pp. 97-111.

Moen, Tom.

1959. Sexiug channel catfish. Transactions of the
American Fisheries Society, vol. 88, No. 2, p. 149.

Patriarche, Mercer H.

1953. The fishery in Lake Wappapello, a flood-
control reservoir on the St. Francis River, Missouri.
Transactions of the American Fisheries Society,
vol. 82 (1952), pp. 242-254.

Patriarche, Mercer H., and Edward M. Lowry.

1953. Age and rate of growth of five species of
fish in Black River, Missouri. University of
Missouri Studies, vol. 26, pp. 99-105.

Sarbahi, Daya Shankar.

1951. Studies of the digestive tracts and the digestive
enzymes of the goldfish, Carassius auratus (Lin-
naeus), and the largemouth black bass, Mirropterus
salmoides (Lacepede). Some anatomical work on
digestive tract. Biological Bulletin, vol. 100,
pp. 244-257.

Smith, Stanford H.

1954. Method of producing plastic impressions of
fish scales without using heat. U.S. Fish and
Wildlife Service, Progressive Fish-Culturist, vol.
16, No. 2, pp. 75-78.

Tiffany. L. H.

1920. Algal food of the young gizzard shad. Ohio
Journal of Science, vol. 21, pp. 113-122.
Trautman, Milton B.

1957. The fishes of Ohio. Ohio State University
Press, Columbus, xvii + 683pp.
Van Oosten, John, H. J. Deason, and Frank W.
Jobes.

1934. A microprojection machine designed for the
study of fish scales. Conseil Permanent Inter-
national por l'Exploration de la Mer, Journal du
Conseil, vol. 9, No. 2, pp. 241-248.
Velasquez, Gregorio T.

1939. On the viability of algae obtained from the
digestive tract of the gizzard shad, Dorosoma
cepedianum (Le Sueur). American Midland Natu-
ralist, vol. 22, pp. 376-405.
Vladykov, Vadin D.

1945. Trois poissons nouveaux pour la province de
Quebec. Naturaliste Canadien, vol. 72, pp. 27-
39.
Wier, H. C, and E. P. Churchill.

1945. The anatomy and histology of the digestive
system of the gizzard shad (Dorosoma cepedianum
Le Sueur). Proceedings South Dakota Academy
of Science, vol. 25, pp. 34-43.

OTZZARD SHAD IN WESTERN LAKE ERIE

425

BIOACCUMULATION OF RADIOACTIVE GOLD USED AS A SEDIMENT
TRACER IN THE ESTUARINE ENVIRONMENT '

By Thomas W. Duke, John P. Baptist, and Donald E. Hoss
Fishery Biologists (Research), Bureau of Commercial Fisheries, Beaufort, N.C.

ABSTRACT

The accumulation of radioactive gold by selected
members of a marine animal community and sediment
material was followed under laboratory and field condi-
tions. In the laboratory an aqueous solution of radio-
active gold was placed directly in the gut of blue crabs,
toadfish, and croakers. There was little transfer of the
isotope to various tissues in these organisms. A group
of toadfish which were fed radioactive gold in an
aqueous solution retained more of the isotope than did
a group which were fed the same amount of radioactiv-
ity sorbed onto clay particles. Also, crabs, fish, clams,
and samples of bentonite clay were maintained for 25
days in 1,000 liters of cotton-filtered sea water contain-
ing radioactive gold. Crabs accumulated the most

radioactivity followed, in descending order, by clams,
clay, and fish. A field experiment was conducted in
cooperation with the U.S. Army Corps of Engineers in
the Cape Fear River, N.C. Caged and indigenous free-
swimming organisms were exposed to sediment-sorbed
radioactive gold used as a sediment tracer by the Corps.
Oysters, crabs, and fish maintained in cages in the
experimental area were sampled periodically. The
maximum level of radioactive gold in the caged orga-
nisms (70.9 millimicrocuries per gram wet weight tissue)
was detected in oysters 17 hours after the isotope was
released. Indigenous organisms collected 41 hours
after the radioactivity was released contained no
detectable radioactive gold.

The uncontrolled release of radioactivity into
estuarine waters could so contaminate marine
organisms that they would be unsafe for use as food
by man. However, with the use of basic data
from laboratory experiments to evaluate the quan-
tity and rates of release of radioactive materials,
and with sensitive instruments to measure the
resulting levels of radioactivity, radioisotopes can
be released into the natural environment without
adversely affecting seafood organisms. Also, when
released in this manner, radioisotopes can safely
be used in situ to investigate many ecological
problems.

A study was made to determine the bioaccumu-
lation of sediment-sorbed radioactive gold re-
leased into the Cape Fear River. This study was
carried out with investigators of the U.S. Army

Note.— Approved for publication Sept. 2, 1964.

' The work upon which this report is bused was done under the cooperative
agreement between the Fish and Wildlife Service. U.S. Department of the
Interior and the U.S. Atomic Energy Commission.

Corps of Engineers, who used this isotope to trace
sediment movement in the river. Prior to this
investigation, radioactive gold had been used
successfully as a sediment tracer by the Corps of
Engineers in several bays and harbor systems in
the United States.

Determinations of gold in marine organisms
have been reported by Noddack (1939), Vino-
gradov (1944), and more recently by Fukai (1962).
Equilibrium values for the distribution of gold
between sea water and organisms have been cal-
culated by Krone (1959) using the data of both
Noddack and Vinogradov. The capacity of
marine organisms to accumulate radioactive gold
from contaminated sea water or from contami-
nated food organisms has not been determined.

Since marine organisms could be exposed to
radioactive gold used in sediment tracer experi-
ments, an evaluation of the accumulation of this
isotope by several marine organisms was made by
(1) conducting laboratory experiments to deter-

FISHERY BULLETIN: VOLUME 65, NO. 2

427

mine the behavior of gold in sea water, and the
translocation of this element in several animals;
(2) observing the transfer of radioactive gold from
sea water to a community maintained in a large
salt-water tank; and (3) measuring the accumula-
tion of the isotope in animals and sediments in the
natural environment.

PRELIMINARY LABORATORY
EXPERIMENTS

The behavior of radioactive gold in sea water,
its affinity for sediments, and its assimilation
by individual organisms were studied prior to
following the movement of radioactive gold
through a community of organisms. Character-
istics of radioactive gold in sea water and the
effect of salinity on the sediment-sorption of this
isotope were observed. Bentonite clay composed
of montmorillonite clay minerals was used in the
sediment-sorption experiments because of the
natural occurrence of these minerals in marine
sediments and because of their reported sorptive
properties (Grim, 1953). Experiments on the
assimilation of radioactive gold by individual
animals were conducted in sea water ranging in
salinity from 28 to 32 %o and having a tempera-
ture range of 27.0° to 30.2° C. These animals
included blue crabs, Callinectes sapidus; oyster
toadfish, Opsanus tau; and Atlantic croakers,
Micropogon undulatus; all collected near Beaufort,
N.C.

Gold 199 was selected in preference to gold 198
because of its longer half-life (3.1 days compared
with 2.7 days) and its availability in the carrier-
free form (2.09 X106 curies (c.)/gram). The gold
199, in the form of auric chloride was supplied
from Oak Ridge, Tenn.

The radioactivity content of sediment, water,
and animals in these preliminary experiments was
measured with a scintillation detector large enough
to contain live animals (4J{ inches diameter by
9 inches long) and a single-channel gamma spec-
trometer. Measurements were corrected for de-
cay, geometry, and background.

BEHAVIOR OF RADIOACTIVE GOLD IN SEA WATER

The behavior of tracer amounts of radioactive
gold in aqueous solutions was investigated by
Schweitzer and Bishop (19.53). These investiga-
tors have shown by filtration and cent rif ligation
that gold (in concentrations less than 10"8 M)

appears to behave as a radiocolloid in certain
aqueous solutions ranging in pH from 2 to 12.
Schweitzer and Jackson (1952) also discussed the
use of cation exchangers in the identification of
radiocolloids. The uptake of a cationic tracer by
an exchanger should decrease with an increase in
the cationic concentration of the solution. If tbe
tracer is a radiocolloid, however, the uptake
increases as the cationic concentration increases.
This is attributed to the effects of the cations
acting as a coagulant and the exchanger acting as
an absorbent.

Several experiments were conducted in this
study to determine, qualitatively, the behavior of
radioactive gold in sea water. A water sample
was prepared by adding 200 microcuries (/xc) of
gold 199 (4.9X10"11 M) to 1 liter of Millipore-
filtered sea water of 30 %o salinity and a pH of
8.2. The temperature of the water was main-
tained at 25° ±2° C. during the experiment.
Centrifugation of 500 ml. of this sample at 3,000
r.p.m. for 15 minutes forced 58 percent of the
radioactivity to the bottom of the tube indicating
that gold particles had been formed. When 500
ml. of the initial sample were passed through a
Mfilipore filter of 45 millimicrons (m/x) pore
diameter, 100 percent of the radioactivity was
removed. Even though some of the gold could
have been retained as a result of pores being
clogged by large molecules, the gold in sea water
appeared to be particulate, rather than ionic.

Further indications of the properties of radio-
active gold in sea water were obtained by observing
the sorption of gold onto clay. Equal amounts
(200 /iC.) of gold 199 were placed in four tanks,
each containing 1 liter of millipore-filtered water
and 1 g. of clay. The first tank contained distilled
water; the second, water having a salinity of
8°/00; the third, 24°/00; and the fourth, 34%0.
The waters having salinities of 8°/00 and 24°/00
were prepared by adding appropriate amounts of
distilled water to sea water having a salinity of
34%o- The water in the tanks was agitated for
15 minutes and allowed to stand for 24 hours.
The clay slurry was withdrawn from each tank,
centrifuged, and the water decanted. The clay
was then dried and the amount of radioactive
gold measured.

The uptake of gold 199 on clay increased as the
salinity increased (fig. 1). There are at least two
possible explanations for this sorption phe-

•IL'S

U.S. FISH AND WILDLIFE SERVICE

5 10 15 20 25 30

SALINITY IN PARTS PER THOUSAND

Figure 1. — Sorption of gold 199 by montmorillonite clay
from sea water with increasing salinity.

nomenon: (1) An increase in salinity caused the
clay to clump, and radioactive gold was trapped
within the clumps; and (2) The increase in salinity
caused the gold particles to coagulate and to sorb
more readily onto the clay. If the latter ex-
planation is accepted as correct, it would appear
that radioactive gold was colloidal in this sample
of sea water.

DISTRIBUTION OF RADIOACTIVE GOLD IN BLUE
CRABS

Edible portions of an organism such as a blue
crab can be relatively free from radioactivity even
though the total radioactivity content of the
organism is high. This is possible when the
activity is isolated in the stomach or associated
with the highly sorptive carapace and other
external sites. That this does occur was shown by
determining the distribution of ingested radio-
active gold in the blue crab. Twelve crabs with
an average weight of 152 g. were made radioactive
by pipetting 75.7 jic. (50 microliters) of gold 199
directly into the cardiac stomach of each crab.
They were then placed in flowing sea water. At
intervals of 3, 4, and 5 days after dosing, three
crabs were killed, dissected, and measured for
contained activity.

Radioactivity content of tissues at 4 days in-
dicated that only a small portion of the gold 199
was assimilated from the stomach (table 1). In
view of the short half-life of the isotope, more than

tracer amounts of radioactive gold would need to
be ingested rapidly in order to build up concen-
trations in edible tissues.

DISTRIBUTION OF RADIOACTIVE GOLD IN
TOADFISH

Bottom feeders, such as the oyster toadfish,
could become radioactive by taking in sediments
with loosely bound sorbed activity. If the
radioactivity were tightly bound to the sediment
particles, however, the sediment-sorption phe-
nomenon would reduce the possibility of animal
contamination by retaining and confining the
radioactivity.

Table 1. — Radioactivity content of crab tissue 4 days after
an oral dose of 75.7 pc. of gold 199

Tissue

Activity

Dose in
entire
tissue

9.3X10-1
8.4X10-1
1.6X10-1
6.3X10-2
2.6X10-2
3.8X10-3
1.7X10-3

Percent
12

Gills

.08

.04

Total

To test the capacity of fish to "strip" radio-
active material from sediments, five male toadfish,
average weight 325 g., were each force-fed 75.7
nc. of radioactive gold dispersed in 2 ml. of sea
water. Five other males of similar size were fed
the same amount of radioactivity sorbed onto 25
mg. of montmorillonite clay suspended in 2 ml. of
sea water. The sea water used in both instances
had a salinity of 30%o and a pH of 8.1. After
the fish had been fed the isotope, they were placed
in flowing sea water. Forty-eight hours later,
the fish were killed and dissected, and the amount
of radioactive gold in various tissues was measured.

A comparison of the activity of tissues from
both groups of fish shows that most of the gold
remained sorbed onto the clay as it passed through
the digestive system of the fish (table 2). The
fish fed the isotope in sea water retained more
activity than those fed the isotope sorbed onto
clay.

DISTRIBUTION OF RADIOACTIVE GOLD IN
CROAKERS

The gastro-intestinal absorption and distribu-
tion of gold 199 in the tissues of the croaker were
determined after 75.7 pc. of the isotope were

RADIOACTIVE GOLD USED AS A SEDIMENT TRACER

429

Table 2. — Radioactivity content of toadfish tissues follow-
ing oral doses of gold 199

Tissue

Gold adminis-
tered in
solution

Gold adminis-
tered sorbed
onto sediment

fC./g.
3.6X10-1
1.5X10-1
1.1X10-1
4.3X10"!
4.0X10-J
4.0X10-'

»c./g.

6X10-3

8X10-<

Out

5X10-2

Gill

2X10-<

IX 10->

Blood.-

5X10-<

pipetted into the stomachs of six fish. The fish
were then placed in flowing sea water. Three were
killed, dissected, and tissues were measured for
radioactive gold content after 78 hours and three
after 148 hours.

Less than 1 percent of the dose was assimilated
by the tissue, about 99 percent having been elim-
inated within 78 hours (table 3). Of the rela-
tively small amount assimilated, kidney and gills
had the highest concentrations of gold 199 per
unit weight. After 148 hours the gills and spleen
had the highest concentrations. The increase in
gold 199 content in some of the tissues during the
period from 78 to 148 hours is probably the result
of continued assimilation from the digestive tract
and translocation of gold 199 from other tissues.

Table S.-

-Distribution

of radioactive

gold in croaker tissue

Tissue

Dose

78 hours

148 hours

Percent
0.038
.035
.017
.006
.003
.002
.001

Percent
0 01

Gills

056

.009

.02

.03

Heart

.0008

Spleen

.042

.001

EXPERIMENTAL ENVIRONMENT STUDY

Since the planned application of radioactive
gold in the Cape Fear River would expose the
community of indigenous organisms further lab-
oratory studies were conducted with a marine
community maintained in a large tank. Data
obtained from tank experiments involving relatively
large volumes of sea water (1,000 1.) and a com-
munity of organisms have advantages over data
for individual species held in smaller volumes of
water. Increasing the volume of water enlarges
the experimental environment, and chronic as well

as acute contamination can be observed since
observations can be made over longer periods of
time because of the improved physiological con-
dition of the organism.

An experimental environment was established
to follow the movement of radioactive gold in a
marine community. The community, which con-
sisted of clams and clam shells, Mercenaria mer-
cenaria; blue crabs; and sheepshead minnow,
Cyprinodon variegatus; as well as sediment samples
of clay, was installed in a large (172 by 117 by
61 cm.) fiberglass tank containing 1,000 1. of
cotton-filtered sea water (table 4). Ten clams
were placed directly on the bottom of the tank,
and 10 in the sediment. Enough gold 199, as
AuCl3, was added to the water to give a con-
centration of 0.0142 juc/ml. After the gold was
added, the pH of the water was 8.1. Throughout the
experiment the water temperature was maintained
at 21°± 3° C. and the salinity at 32±0.10%o,
the latter by adding distilled water when nec-
essary to compensate for evaporation. A plastic
impeller pump circulated the water continuously.

Clay sediment introduced into the tank was
first placed in glass bowls (3 cm. deep by 12.7
cm. in diameter) after being thoroughly wetted as
follows: 6 kg. of clay were suspended in 10 liters
of sea water for 48 hours, and the excess water
was decanted from the clay, leaving it with a
pastelike consistency. In each bowl, 200 g. of
the wet clay (125 g. dry weight) were placed
forming a smooth substrate that was not disturbed
by water circulation.

The radioactivity content of whole animals and
sediment was measured periodically, with the
organisms afterward being returned to the tank.
Oysters, clams, and crabs were prepared for
radioactivity analysis by wrapping them in a thin
transparent plastic sheet. Fish were placed in
dark glass jars containing nonradioactive sea
water and counted for 3 minutes. Sediments
were removed from the tank with a small diameter
(2.5 cm.) core sampler and were not returned to the
tank. This procedure of measuring the activity
in a whole animal eliminated the need for killing
it, and the number of individuals was not reduced
with sampling. Also, uptake could be followed
on the same individual throughout the experiment.

Appropriate corrections were made for decay,
geometry, and background on all radioactivity
measurements unless otherwise stated.

430

U.S. FISH AND WILDLIFE SERVICE

^■■°-T

-0"5-

— 0

A s • _, —
p • / ^^

0/ tf

a C

00 000

-of

I
1

'/'
//

/ ■ -

— 8_

- ■
'"A.

10.000

f
1

*"*»- *

)

O Crabs ^^

• Sediments

Q Clams

■ Clam shells

A Minnows

A ■ ■ Water

1,1,1,

Table 4. — Composition of experimental environment
showing distribution of gold 199, 600 hours after intro-
duction of the isotope

300

HOURS

Figure 2.

-Movement of gold 199 in an experimental
marine environment.

Components of the community rapidly accu-
mulated radioactive gold and reached an apparent
steady state after 225 hours (fig. 2). There was
not a direct relation between the accumulation of
the radioactive gold by the components and the
loss of the isotope from the water. Even though
the radioactive content of the organisms and
sediments did not increase after 225 hours, the
radioactivity content of the water continued to
decrease. This decrease was attributed to sorp-
tion of the radioactivity to exposed surfaces in the
tank (a total area of 29,784 cm.2) and to accu-
mulation by patches of bacterial film that appeared
on the sides of the tank after the experiment had
been in progress about 120 hours. Although it
was not possible to measure the total amount of
film present, 1 g. of this material contained 57
mc. of radioactive gold after 600 hours. The
distribution of the radioactive gold in the

Component

Individuals

Total wet
weight

Gold 199

content after
600 hours

Water

Number

1.0 x 101

1,000

620

2,800

130

liC.

4.600

Sediment

Crabs

20
10
10

Clam she Us

Fish

Total uptake by com-
ponents

6,610
7,590

Loss unaccounted for. _ .

community at the end of the experiment is shown
in table 4.

Crabs accumulated more radioactive gold than
the other organisms in the experiment. As an
estuarine species, blue crabs are a part of a marine
community that appears most likely to be ex-
posed to radioactive material in any appreciable
concentration. As bottom-dwelling, omnivorous
predators and scavengers, blue crabs are, at one
time or another, in contact with almost all of the
abiotic components of their environment. The
carapace and gills offer many surface sites for
sorption of materials from the environment. Gill
area alone of a blue crab has been estimated to be
about 275,000 mm.2 (Gray, 1957).

Although sediments often are not included in
the food web of marine organisms, many organisms
can utilize materials sorbed onto sediments as a
source of nourishment. Thus, it is necessary to
observe accumulation of gold by sediments as well

Figure 3. — Sorption of gold 199 by sediment in an
experimental environment. Curve A is activity cor-
rected for decay, curve B is observed activity.

RADIOACTIVE GOLD USED AS A SEDIMENT TRACER

431

as accumulation by the biota. In the present
experiment, an increase in sediment activity up to
the 250th hour occurred (figs. 2 and 3). From
this time until the experiment ended, the activity
was maintained with no significant increase or loss ;
it appears that the sediments were saturated with
gold at 250 hours (curve A, fig. 3). The actual
activity of the sediments, uncorrected for decay,
is shown in curve B of figure 3. The latter values
would be of more importance to the health
physicists, as they show the actual amount of
activity present in the sediments. If the gold
were released into sea water in a restricted area
where dispersion was minimal, these results in-
dicate that natural decay would exceed uptake
after about 1 50 hours with a resulting decrease in
sediment activity.

Live clams accumulated more radioactivity than
did the separated clam shells. Since clams feed by
filtering suspended matter from large volumes of
water passing over their gills, they are susceptible
to contamination from particulate radioactive
materials released into the estuarine environ-
ment. As bottom dwellers, restricted in their
movements, they are in contact with sediments
and associated radionuclides. A comparison of
the mean radioactivity content of 10 clams to 10
separated clam shells on a unit weight basis by a
standard t test at the .05 level showed that live
clams were significantly more radioactive. The
higher concentration of the isotope in the live
animals was attributed to the movement of water
through the animals. This movement would ex-
pose internal tissues as well as shell surfaces to
contaminated water.

The clams placed on top of the sediment at the
beginning of the experiment accumulated much
less radioactive gold than those placed in areas
without sediment. As the experiment progressed,
the clams burrowed into the sediments, leaving
only a portion of their shells exposed. The bur-
rowing clams contained 38 percent less activity
than those that remained on the bottom surface
of the tank — an indication that a large portion of
the gold accumulated by clams was due to sorption
of the shell.

Fish accumulate radioactive materials by ad-
sorption, absorption, or by ingestion. In nature,
these three modes of uptake can occur simulta-
neously, singly, or in various combinations,
depending upon the physical state of the isotope

432

in the water, the food habits of the fish, and the
length of time the fish remains in a polluted area.
In this experiment, the sheepshead minnow accumu-
lated the least amount of radioactive gold of any
test organisms (fig. 2). The activity of the fish
decreased during the latter stages of the experi-
ment. A sloughing off of the epidermal mucous
layer containing sorbed activity could account for
the loss, or the physiological condition of the fish
could have deteriorated and their rate of metab-
olism changed.

FIELD INVESTIGATIONS

The accumulation of radioactive gold released
into the Cape Fear River was observed in both
indigenous organisms and in caged organisms
collected in Beaufort and maintained in the river.
The investigations were coordinated with the
release of radioactive gold which had been sorbed
onto sediment particles.

The specific problem under investigation by the
U.S. Army Corps of Engineers was to determine
if sediment being deposited in the channels of the
Cape Fear River, N.C., near the Sunny Point
Army Piers near Southport, N.C., had been
transported by currents from a spoil area on the
opposite side of the river (U.S. Army Corps of
Engineers, 1964). The answer was sought by
tagging a small quantity of the sediment with
gold 198, releasing this sediment in the spoil area,
and tracing its distribution with an underwater
scintillation probe mounted on a sled. The
sediment was tagged by first forming a slurry into
which 5 c. of gold 198 chloride were thoroughly
mixed to allow maximum sorption. This was
done in a special conical-bottomed container
which served also as the release mechanism for
the tagged sediment. The container floated in
the water and was towed by boat "over a prede-
termined course while the tagged sediment was
being released. The entire procedure has been
described in greater detail by Krone (1960).

Gold-tagged sediments were released at two
different sites. The first 5 c. "drop" was made on
October 24, 1962, at 6 p.m., at high tide, along an
east-west line on the southern end of the Spoil
area (fig. 4). A second 5 c. drop was made on
the northern end of the spoil area on October 25
at 4 p.m., also at high tide. A water sample
collected in the drop zone at this time had a

U.S. FISH AND WILDLIFE SERVICE

Figure 4. — Location of sampling stations and gold tracer drop zones in the Cape Fear River.

salinity of 24 %o, temperature of 18° C, and
pH of 7.9.

Animals and sediment from the drop zone area
were collected before and after the release of the
labeled sediment. Samples of sediment and sea
water, and of blue crabs; Atlantic croaker; star
drum, Stellijer lanceolatus: flounder, Paralichthys

sp.; and American menhaden, Brevoortia tyrannus,
were collected 1 week prior to the first drop in
order to measure background activity. Orga-
nisms and sediment were collected again on the
third day following the release of the labeled
sediment. In addition to those species collected
before the release of labeled sediment, the white

RADIOACTIVE GOLD USED AS A SEDIMENT TRACER
774-711 O — 66 10

433

shrimp, Penaeus setijerus, appeared in samples
taken after the release. Sediment samples from
the drop zone were composed mostly of sand.
Additional information on the sediments is given
by the U.S. Army Corps of Engineers (1964).

Cages containing various estuarine organisms
were placed at six stations around the proposed
drop zone 24 hours before the scheduled release
(fig. 4). Test animals at each station included
25 blue crabs; 50 oysters, Crassostrea virginica;
and 50 mummichogs, Fundulus heteroclitus . Ten
croakers were included at stations IV, V, and VI.
The blue crabs were kept in separate cages to
prevent predation on the other test animals.
Also, at each station, plastic petri dishes filled
with montmorillonite clay were placed in minnow
traps to test for adsorption of gold 198. Five to
ten animals of each species were removed from the
cages for each sample.

The radioactivity content of the field samples
was measured at the Bureau of Commercial
Fisheries Radiobiological Laboratory, Beaufort,
N.C., 110 miles from the sampling area. The
detector system consisted of a 3-inch Nal(Tl)
crystal coupled to a single-channel gamma spec-
trometer. Sediment and biological samples were
placed in individual plastic bags, packed in an ice
chest, and transported to the laboratory as soon
as possible after sampling. Water samples were
held in screw cap jars. If the water samples were
found to be radioactive, the water was Millipore-
filtered and counted again, along with the separated
material, to determine whether the radioactive
gold was associated with suspended material.

The various samples were measured for radio-
activity in a manner that permitted the comparison
of ^organisms, sediments, and water. To make
these comparisons, it was necessary that the radio-
activity in all of the samples be measured under
similar conditions of geometry. Organisms con-
taining gold 198 were measured for radioactivity
before and after being dissolved in nitric acid and
diluted to 900 ml. A factor was thus obtained for
converting measurements made on the intact
organisms to measurements which would be ob-
tained after dissolving and diluting the organisms
to 900 ml. A factor was obtained for the sedi-
ments in a similar manner, except that no acid
was used and Calgon was added as a wetting agent.
NO preparation was necessary to measure gold 199
in the 900 nil. samples of water. Since radio-

activity measurements in intact organisms and
sediments could be converted to measurements
based on their being contained in a 900-ml.
volume of water, and since all measurements of
water were for 900 ml., it was possible to compare
activity contained in these three types of samples.

The radioactivity content of water, sediments,
and biota varied widely between stations. Bio-
logical samples from stations III and VI did not
contain measurable amounts of radioactivity at
any time (table 5). As one would expect, bio-
logical samples from station II, located directly
in the drop zone, contained higher concentrations
of radioactivity than those of other stations.
Lateral dispersion of radiogold was indicated by
the increase in activity in the crabs and oysters
from stations I and IV after 41 hours elapsed time.

The second application of gold appeared to have
little or no effect on the levels of concentration in
the samples, except perhaps those in station IV.
Oysters and crabs accumulated radioactivity to
maximum level 17 hours after the first radiogold

Figure 5. — Radioactivity content of biota and sediments
from Cape Fear River after release of gold tracer.

434

U.S. FISH AND WILDLIFE SERVICE

application (fig. 5). However, this occurred 5
hours before the second application.

Background samples of biota and water collected
in the drop zone area 1 week prior to the release of
the labeled sediments did not contain measurable
gamma activity in the energy range between 100
and 400 kiloelectron volts (Kev), the setting which
includes the photopeak of radioactive gold. How-
ever, sediment samples contained gamma activity
ranging from 367 to 729 counts per minute per
kg. wet weight at this setting. Biota, water, and
sediments collected from the same area 41 hours
after the release did not show an increase in
radioactive content over the background samples.

Table 5. — Radioactive gold content of field samples '
[Activity m./ic/kg.]

Elapsed
time in

Sample

Station

hours

III

144

Water

Sediment

Fish

Oyster

Clay

Crab

Water

Sediment ...

Fish

Oyster

Clay

Crab

Water

Sediment...

Fish

Oyster

Clay

Crab

Water

Sediment...

Fish

Oyster

Crab

5.1

NS
NS
NS
NS
NS

NS
NS
NS
15.7

14.8

6.8
NS
NS
23.8
45.6
27.3

4.7
60.3

NS
70.9

61.6

NS
NS
NS

31.1
NS

22.9

2.96

NS
NS
NS

NS
NS

4.2

NS
NS
NS
24.5

24.9

NS
NS
NS
NS
NS

4.12

NS
36.90
40.22

NS
NS
NS
14.1

19.0

NS
NS
NS
NS

1 NS indicates activity not significantly greater than background; dash
indicates no sample was taken.

DISCUSSION

The potential hazards accompanying the release
of radioactive material into the marine environ-
ment should be investigated so that the most
dangerous situation possible is evaluated. The
accumulation of radioactive gold from sea water
by the animal community contained in the large
tank was a simulation of this extreme situation:
The closed system offered no opportunity for the
animals to escape the contaminated area, and
there was neither inflow of nonactive sea water nor
outflow of contaminated water. Under these
controlled conditions, organisms and sediments

accumulated the isotope from sea water, with
crabs and filter-feeding organisms accumulating
the isotope to the greatest extent.

Surface sorption of radioactive gold, no doubt,
is an important factor contributing to rapid accu-
mulation by marine organisms and sediments.
This is based on the observation that 50 percent
of the isotope added to the water in an experi-
mental environment moved very quickly to orga-
nisms and sediments within the tank. It is known
that biological accumulation of a radiosotope by
sorption occurs rapidly. Further, it has been
shown that gold occurs in sea water in a particu-
late state. Since particles have difficulty passing
through biological membranes, surface sorption is
most important in their accumulation by marine
organisms. The importance of surface sorption
in the accumulation of radioactive gold by orga-
nisms was demonstrated experimentally when the
radioactive content of clams buried in sediment
was shown to be less than that of clams resting on
the smooth bottom surface of the tank. Although
the buried clams had less area exposed, the same
average amount of water should have passed
through their siphons as through the siphons of
those resting on the bottom. If all the accumu-
lation of gold had been a result of metabolism, the
gold content of buried and exposed organisms
should have been the same.

The literature contains several references per-
taining to the surface accumulation of material
from sea water. As early as 1937, Harvey demon-
strated that particulate matter such as ferric
hydroxide was associated with phytoplankton cells
by electrostatic attraction to external surfaces.
Also, Goldberg (1952) observed that particulate
and colloidal iron was utilized by Asterionella
japonica. Rice and Willis (1959) showed that
particulate cerium 144 became attached to Nitz-
schia cells as a result of particles and cells coming
in contact with each other and sticking.

The distribution of this isotope within the
animals was observed by placing large quantities
of radioactive gold directly into the gut of several
estuarine animals. Those organs associated with
excretion retained more gold 199 than did others,
suggesting that the gold was simply being excreted
rather than hems' stored or utilized . The principal
route of gold administered as an oral dose to
mammals was reported by Spector (1956) to be
directly from the alimentary tract to the feces with

RADIOACTIVE GOLD USED AS A SEDIMENT TRACER

435

little absorption along the way. In the present
study, little, if any, radioactive gold was found in
the organs of fish that were fed this isotope sorbed
onto clay.

In field studies, animals and sediment main-
tained in cages in the drop zone sorbed little
activity. This could have been caused by the
tremendous dilution by river water and strong
currents, and to the short physical half-life of the
gold isotope. Since it was demonstrated experi-
mentally that the animals retained little activity
from ingested labeled sediment particles, the
initial accumulation of activity was perhaps from
unbound gold that was not sorbed onto sediments
in the mixing hopper but remained in the water
phase of the slurry.

Since gold is not biologically essential and is not
concentrated significantly by estuarine animals,
the isotope gold 198, with its short physical half-
life of 2.7 days, appeared to be a safe and effective
tracer for following sediment movement. Even
though as much as 5 c. of gold 198 were released
in the Cape Fear River at one time, the maximum
concentration found in any of the animals tested
was 70.9 X10-6 nc. per g. of oyster at station II
(table 5). This is slightly in excess of the maxi-
mum permissible concentration (MPC) for gold
198 in water effluent released in an unrestricted
area, i.e., 5X10-6 /iC./ml. (Code of Federal Regula-
tions, 1960). However, station II was purposely
located in the drop zone so that the caged animals
would be subjected to the most extreme conditions
of contamination. There is no evidence now that
radiation from the low levels of gold 198 involved
in these investigations affected the biota.

ACKNOWLEDGMENTS

Thomas J. Price provided unpublished data
on mollusks and George H. Rees furnished data
on blue crabs. The U.S. Army Corps of Engineers
and its consultant, R. B. Krone, cooperated and
assisted.

LITERATURE CITED

Code of Federal Regulations.

1960. Title 10— Atomic Energy. Part 20— Stand-
ards for protection against radiation. Federal
Register, November 17, 11 pp.

FlJKAI, RlNNOSUKE, AND W. W. MeINKE.

1962. Activation analyses of vanadium, arsenic,
molybdenum, tungsten, rhenium and gold in ma-
rine organisms. Limnology and Oceanography,
vol. 7, pp. 186-200.

Goldberg, E. D.

1952. Iron assimilation by marine diatoms. Bio-
logical Bulletin, vol. 102, pp. 243-248.

Gray, I. E.

1957. A comparative study of the gill area of crabs.
Biological Bulletin, vol. 112, pp. 34-42.
Grim, R. E.

1953. Clay mineralogy. McGraw-Hill Book Com-
pany, Inc., New York, N.Y., 384 pp.

Harvey, H. W.

1937. The supply of iron to diatoms. Journal of

the Marine Biological Association of the United

Kingdom, vol. 22, pp. 205-219.
Krone, R. B.

1959. Silt transport studies utilizing radioisotopes.
Second Annual Progress Report. University of
California, Hydraulic Engineering Laboratory and
Sanitary Engineering Laboratory, 123 pp.

Krone, R. B.

1960. Methods for tracing estuarial sediment trans-
port processes. Report for San Francisco District
Corps of Engineers, U.S. Army. Contract No.
DA-04-203 Civeng-59-99, 57 pp.

Noddack, Ida, and Walter Noddack.

1939. Die Hautigkeiten der Schwermetalle in Meere-
stieren. Arkiv for Zoologi, band 32 A, N:o 4, pp.
1-35.
Rice, T. R., and V. M. Willis.

1959. Uptake, accumulation, and loss of radioactive
cerium 144 by marine planktonic algae. Lim-
nology and Oceanography, vol. 4, pp. 277-290.
Spector, W. S. (Editor).

1956. Handbook of biological data. W. B. Saunders
Co., Philadelphia, Pa., 584 pp.
Schweitzer, G. K., and Morrison Jackson.

1952. Radiocolloids. Journal of Chemical Educa-
tion, vol. 29, pp. 513-522.

Schweitzer, G. K., and W. N. Bishop.

1953. Low concentration chemistry. VI. Some
properties of tracer gold in solution. Journal of the
American Chemical Society, vol. 75, pp. 6330-6332.

U.S. Army Corps of Engineers.

1964. Radioactive sediment tracer tests, Cape Fear
River, N.C. U.S. Army Engineer Waterways
Experiment Station, Miscellaneous Paper No.
2-649, 14 pp.

Vinogradov, A. P.

1935-44. The elementary chemical composition of
marine organisms (Khimicheskil elementarily! sos-
tav organizmov morya). In three parts. Akade-
miya Nauk SSSR. Trudy Biogeokhimicheskol
Laboratorii. Part I, in vol. 3, 1935, pp. 63-278;
Part II, in vol. 4, 1937, pp. 5-225; Part III in vol. 6,
1944, pp. 5-273. (Translation by Julia Efron and
Jane K. Setlow, with bibliography edited and newly
enlarged by Virginia W. Odum, Sears Foundation
for Marine Research (New Haven, Conn.), Memoir
Number 2, 1953, 647 pp.).

436

U.S. FISH AND WILDLIFE SERVICE

A GENERIC KEY TO THE PROTOZOEAN, MYSIS, AND POSTLARVAL STAGES
OF THE LITTORAL PENAEIDAE OF THE NORTHWESTERN GULF OF
MEXICO '

Harry L. Cook, Fishery Biologist (Research), Bureau of Commercial Fisheries Biological Laboratory

Galveston, Tex.

ABSTRACT

An illustrated key presenting criteria for differentiat-
ing the stages and substages of Gulf of Mexico penaeid
larvae (and post larvae) from comparable stages of the
more common nonpenaeids is presented. A second key

permits generic identification of penaeid protozoean,
mysis, and postlarval stages. All genera are illustrated,
and a table of important diagnostic characters is
included.

Shrimp of the Family Penaeidae which support
valuable commercial fisheries in the northwestern
Gulf of Mexico are being studied comprehensively
by fishery scientists at the Bureau of Commerical
Fisheries Biological Laboratory in Galveston, Tex.
To properly manage such fisheries, it is necessary
to fully understand the dynamics of the shrimp
populations upon which they depend. This
capability requires, in turn, as complete a knowl-
edge as possible of the life history of the species
involved.

Studies of the early (planktonic) life history of
the Gulf's commercially important shrimps have
been hampered by difficulties encountered in
distinguishing larvae of these species from those of
lesser importance. Fortunately, there has been
considerable research on the description and
general systematica of larval and postlarval
Penaeidae both in this country and abroad. As a
result, all the littoral genera known to occur in the
northwestern Gulf of Mexico have had representa-
tives— although not necessarily of indigenous
species — at least partially described. The princi-
pal problem, therefore, was one of consolidating all

Note.— Approved for publication Sept. 17, 1964.

1 Contribution No. 189, Bureau of Commercial Fisheries Biological Labora-
tory, Galveston, Tex.

the available information and ascertaining what
portions of it might help describe the local penaeid
larvae. The intent of this paper is to present
criteria that will aid in distinguishing larvae and
postlarvae of the genus Penaeus Fabricius from
those of Parapenaeus Smith, Sicyonia H. Milne
Edwards, Solenocera Lucas, Trachypeneus Alcock,
and Xiphopeneus Smith, the five other littoral
genera found locally.

The material made available for examination
during this study was collected systematically
between March 1959 and March 1960 and during
January to December 1961. From January to
September 1961, plankton was sampled with a
Gulf-V net to depths of 45 fathoms between Cam-
eron, La., and Freeport, Tex. In September, the
sampling program was enlarged to include the area
between Morgan City, La., and the mouth of the
Colorado River, Tex.

Although various larval stages of several species
represented in this area had been recorded, there
were no established criteria for differentiating the
penaeid larvae. Consequently, as new or thereto-
fore unrecognized penaeid larvae and postlarvae
were found in the plankton samples, they were
assigned a code number and a reference sketch of
them was made. Through the use of descriptions

FISHERY BULLETIN: VOLUME 65, NO. 2

43-

taken from the literature, and by comparison with
larvae reared in the laboratory from eggs of known
parentage, planktonic larvae were assigned to
genera. Subsequent examination of accumulated
material revealed the presence of protozoeal, mysis,
and postlarval characters which remained constant
within each genus. These characters were, in
turn, used as criteria to construct a key to local
genera. A key based for the most part on plank-
tonic rather than laboratory-reared material has
its limitations, but the scarcity of information
concerning penaeid larvae from this area never-
theless justifies its presentation at this time.

Despite the fact that Penaeus aztecus Ives
(brown shrimp); P. duorarum Burkenroad (pink
shrimp); Sicyonia brevirostris (Stimpson) and
S. dorsalis (Kingsley) (rock shrimps); Trachy-
peneus similis (Smith); and Xiphopeneus krfiyeri
(Heller) (seabob) have been reared successfully
through the nauplial stage under laboratory
conditions, the nauplii were found to be so similar
as to defy attempts to fit them into a key. Al-
though differences in setation are minor or absent,
the lack of a dorsal protuberance (fig. If), as well
as larger relative size, serves to distinguish
nauplii of the genus Penaeus. In genera other
than Penaeus, this protuberance is present on the
dorsal surface of the body above the insertion
of the second antennae.

Within a given developmental stage (e.g.,
Nauplius II, Protozoea I, etc.), the size ranges of
penaeid larvae as a whole are extremely variable,
although in the northern Gulf, larvae of the genus
Penaeus are generally larger than those belonging
to comparable stages of other genera. Hudinaga
(1942) found that the protozoeal stages of P.
japonicus Bate exhibited intermolt growth, the
occurrence of which may also be true for other
stages as suggested for nauplii of Xiphopeneus
krp'yeri by Renfro and Cook (1963). The possi-
bility also exists that larvae (and postlarvae)
of the same species grow dissimilarly at different
times of the year. Since the relative size at each
stage overlaps considerably between, as well as
within, the various genera, it should be used
with discretion for purposes of identification.

While the number of substages in each penaeid
larval stage described in the literature has been
found to vary, the normal situation in the north-
western Gulf of Mexico — as ascertained from
material in plankton collections — seems to be

five nauplial, three protozoeal, and three mysis
substages. Examples of departure from this se-
quence are provided by the larvae of Sicyonia
brevirostris which, when reared in the laboratory,
appeared to pass through four mysis substages,
and by those of Parapenaeus sp. which, as de-
termined from sample material, also have at
least four. Such apparent anomalies suggest
that descriptions of penaeid larvae obtained
either from rearing experiments or plankton
samples must be viewed with caution until more
is known of the effects of environmental factors
on early growth and morphology.

Table 1, in addition to presenting the principal
diagnostic characters included in the following
key, also furnishes other valuable characters
for distinguishing larvae and postlarvae.

All illustrations are intended to clarify generic
characteristics and do not represent particular
species.

KEY TO STAGES AND SUBSTAGES OF
PENAEID LARVAE AND EARLY POST-
LARVAE

1 Body simple, unsegmented; three pairs of ap-

pendages arising from anterior portion of body,
first unbranched, second and third branched;
paired caudal spines arise from posterior end of

body (Nauplius) 2

Not as above 7

2(1) Body pear shaped; pairs of caudal spines of equal
length, extending straight posteriorly; lateral
setae on appendages arise singly or in pairs;
appendages lack spines or processes such as would
be utilized for feeding purposes; carapace present
only as a close-fitting rudiment in later stages

(Penaeid nauplius fig. 1) 3

One or more of the following characters present:
body elliptical; pairs of caudal spines of unequal
length or extending medianly, crossing one
another; lateral setae on appendages arising in
clusters; spines or processes such as would be
utilized for feeding purposes present; a well-
developed or prominent carapace present

Nonpenaeid nauplius

3(2) Five setae on exopod of second antenna; one pair
of caudal spines; surface of body between inser-
tion of caudal spines convex.. Nauplius I (fig. la)
More than five setae on exopod of second antenna;
one or more pairs of caudal spines; surface of
body between insertion of caudal spines not
convex 4

4(3) Six setae on exopod of second antenna; usually
one, sometimes two, pairs of caudal spines;
surface of body between insertion of caudal spines
flat Nauplius II (fig. lb)

438

U.S. FISH AND WILDLIFE SERVICE

•A Swelling at Base of Mandible

10 Labium

11 Ventral Appendages

Figure 1.— Penaeid nauplii: a, Nauplius I; 6, Nauplius II; c, Nauplius III; d, Nauplius IV; e, and/, Nauplius V.
PENEIDAE OF THE NORTHWESTERN GULF OF MEXICO

More than six setae on exopod of second antenna;
usually three or more pairs of caudal spines;
surface of body between insertion of caudal spines
concave 5

5(4) Seven setae on exopod of second appenadge;
usually three, sometimes four, pairs of caudal
spines; surface of body between insertion of caudal
spines slightly concave; no swelling at base of

mandible Nauplius III (fig. lc)

More than seven setae on exopod of second
antenna; usually more than four pairs of caudal
spines; surface of body between insertion of
caudal spines deeply concave; base of mandible
swollen 6

6(5) Eight setae on exopod of second antenna; usually
five, sometimes six, pairs of caudal spines; slight
swelling at base of mandible; endopod of mandible
never transparent; rudimentary ventral append-
ages posterior to third appendages

Nauplius IV (fig. Id)
Nine setae on exopod of second antenna; usually
seven, sometimes six, pairs of caudal spines; large
subcorneal protuberance at base of mandible;
endopod of mandible frequently transparent;
ventral appendages prominent

Nauplius V (fig. le)

7(1) Large, prominent, carapace followed by a slender
segmented thorax and an abdomen which may or
may not be segmented; two pairs of prominent
appendages arising from anterior portion of body,
the first unbranched, the second branched;

prominent labrum present (Protozoea) 8

Not as above 11

8(7) Carapace does not completely cover thorax;
abdomen bifurcate posteriorly, with each furca
bearing at least seven spines; biramous first and

second maxillipeds well developed, the third
absent or present only as a rudiment; usually, no
spines arise from posterior half of carapace; if
spines present, a dorsal organ (fig. 2d) is present

(Penaeid protozoea fig. 2) 9

One or more of the following characters present:
carapace completely covers thorax; abdomen not
bifurcate; caudal furcae bear less than seven
pairs of spines; first and second maxillipeds not
well developed or third maxilliped well developed;
if numerous spines arise from posterior portion of
carapace, dorsal organ not present

Nonpenaeid protozoea
9(8) Eyes sessile, beneath carapace; pereiopods
absent; abdomen unsegmented

Protozoea I (fig. 2a)
Eyes stalked ; pereiopods present at least as small
buds; abdomen segmented 10

10(9) Uropods not present externally, may be seen
beneath cuticle; pereiopods present only as small
buds; first five abdominal segments without dorsal

spines Protozoea II (fig. 2b)

Uropods present externally; pereiopods rudimen-
tary, but biramous and prominent; first five
abdominal segments with dorsal spines

Protozoea III (fig. 2c)

11(7) Carapace closely fitting with a rostrum that
extends anteriorly between the eyes; five pairs
of biramous pereiopods present, with the exopods
elongate and bearing numerous setae which make
them appear brushlike; six-segmented abdomen
followed by telson and biramous uropods;
pleopods, if present, rudimentary and non-
functional (Mysis) 12

Carapace closely fitting with a rostrum extending
anteriorly between the eyes; five pairs of pereio-

1 |s| flntrpina

2 Endopod 2d Antenna

3 EiOpod 2d Antenna

4 Labrum

5 labtal Sp.ne

6 Mandible

7 l-.t&2d Ma.illj

8 1st, 2d 4 3d Ma.tltped

9 Telson

Figure 2. — Penaeid protozoeae: a, Protozoea I; b, Protozoea II; c, Protozoea III; d, Protozoea III, carapace.
440 U.S. FISH AND WILDLIFE SERVICE

pods present, with exopods absent or present
only as rudiments; six-segmented abdomen fol-
lowed by telson and biramous uropods; five pairs
of setose, functional pleopods present (Post-
larvae) 15

12(11) First three pairs of pereiopods cleft to form
rudimentary chelae; pleura of first abdominal
segment overlap second; antennal blades present;
pleopods develop on first five abdominal segments
simultaneously although they are not necessarily
of equal length; telsor narrow and notched
medianly; uropods without statocysts; usually,
no spines originate from posterior half of carapace
and margins of carapace not serrate ; if spines or
serrations present, a dorsal organ also present

(Penaeid mysis fig. 3) 13

One or more of following characters present:
first three pereiopods not cleft to form rudi-

1 Rostrum

2 Rostral Spine

3 Supraorbital Spine

4 Hepatic Spine

5 First Antenna

6 Antennal Blade

7 Chela

8 Exopod ol Pereiopod

9 Dorsal Abdominal Spine

10 Lateral Abdominal Spine

11 Telson

12 Uropod

mentary chelae; pleura of second abdominal
segment overlap first; antennal blades absent;
pleopods may not be present on all abdominal
segments; telson broad and fan shaped or not
notched medianly; uropods with statocyst;
spines originate from posterior half of carapace or
margins of carapace serrate, with no dorsal organ
present Nonpenaeid mysis

13(12) Pleopods absent Mysis I (fig. 3a)

Pleopods present 14

14(13) Pleopods small and unjointed._ Mysis II (fig. 3b)
Pleopods long and jointed Mysis III (fig. 3c)

15(11) First three pairs of pereiopods chelate; pleura of
first abdominal segment overlapping second;
five pairs of functional pleopods present; gills
covered by carapace; antennal blades present

Penaeid postlarva (fig. 4)
One or more of the following characters present:
first three pairs of pereiopods not chelate; pleura
of second abdominal segment overlapping first;
less than five pairs of functional pleopods present;
gills extending from beneath carapace; antennal
blades absent Nonpenaeid postlarva

Figure 3.- — Penaeid myses: a, Mysis I; 6, Mysis II; c,
Mysis III.

1 Rostrum

2 Antennal Sptr

3 Hepatic Spin*

4 Ptetygostomi

5 Cetvical Sulcus

t. Anlennule

7 Endopod of Pleopod

8 Eiopod ol Pleopod

9 Telson
10 Pleuton

Figure 4. — Penaeid postlarva.

PENEIDAE OF THE NORTHWESTERN GULF OF MEXICO

441

KEY TO GENERA OF PENAEID LARVAE
AND POSTLARVAE

PROTOZOEAE

(Fig. 5)

1 Number of lateral setae on endopod of second

appendage 1 + 1+2 2 Penaeus

Number of lateral setae on endopod of second
appendage not 1 + 1+2 2

2(1) First appendage about twice as long as second; no
spine on anterior margin of labrum; number of
lateral setae on .endopod of second appendage
1+2 + 3 Sicyonia

2 Starting with proximal seta, the number of lateral setae at each point of
insertion is recorded.

First and second appendages of nearly equal
length; a spine present on anterior margin of
labrum; number of lateral setae on endopod of
second appendage may be 1 + 2 + 3 3

3(2) Number of lateral setae on endopod of second ap-
pendage 1+2+2, 1 + 2 + 3, or2 + 2 + 2_ Parapenaeus
Number of lateral setae on endopod of second ap-
pendage not 1 + 2 + 2 or 2 + 2 + 2 4

4(3) Number of lateral setae on endopod of second

appendage 2 + 2 + 3 Solenocera

Number of lateral setae on endopod of second
appendage 2 + 2 5

5(4) Four long, terminal setae on endopod of second

appendage Trachypeneus

Four long and one short terminal setae on endopod
of second appendage Xiphopene us

-.i'l.'.tvf.1

Figure 5. — Penaeid protozoeae: a, Parapenaeus, Protozoea I: b, Penaeus, Protozoea I; c, Sicyoma, Protozoea I; </,
Solenocera, Protozoea I; e, Solenocera, Protozoea 11;/, Trachypeneus, Protozoea I; 17, Xiphopeneus, Protozoea I.

442

U.S. FISH AND WILDLIFE SERVICE

MYSES 2(1) Dorsomedian spines not present on first five ab-

(Fi 6) dominal segments Sicyonia

Dorsomedian spine present on at least fourth and

Carapace and abdomen with many spines; dorsal fifth abdominal segments 3

organ present on dorsal surface of carapace 3 ( % ) Dorsomedian ine not ent on third abdominal

Solenocera gegment 4

Carapace and abdomen without many spines; r4„. „„ ,. ... , . ,

F " ' Dorsomedian spine present on third abdominal

dorsal organ absent -~> segment... ...5

4(3) Lateral spine present on fifth abdominal segment;

rostrum shorter than eye Trachypeneus

Lateral spine not present on fifth abdominal seg-
ment; rostrum as long as or shorter than eye
a Xiphopeneus

5(3) Dorsomedian spine on third abdominal segment

elongate Parapenae us

Dorsomedian spine on third abdominal segment not
elongate Penaeus

POSTLARVAE

(Fig. 7)

1 Total length 6.0 mm. or less 3 3

Total length greater than 6.0 mm 2

2(1) Total length 6.0 mm. to 12.0 mm 5

Total length 12.0 mm. to 25.0 mm 10

3(1) No terminal spines on telson Sicyonia

Terminal spines present on telson 4

c 4(3) Medioterminal spines of telson longer than those

adjacent to it Trachypeneus

Dor5al0rg3n Medioterminal spine of telson equal in length

^ „ to those adjacent to it Penaeus

j/** '^^^-^fU^-l^- (s^ §{1) First abdominal segment with dorsal antero-

U ^f"~f-^C~iz/r median spine Sicyonia

**=. ~ First abdominal segment without dorsal antero-

d ^K^^Z median spine 6

6(5) Pterygostomian spine present; pleopods of fifth
abdominal segment with exopods and endopods

of equal length 7

Pterygostomian spine absent; pleopods of fifth
abdominal segment with endopods inferior to

exopods 8

7(6) Antennules round ; no cervical sulcus on carapace ;

rostrum curved Parapenaeus

Antennules flattened ; well-defined cervical sulcus

present on carapace; rostrum straight. Solenocera

8(5) Antennal spine absent or minute; if present,

subrostral teeth also present . Penaeus

Antennal spine very prominent; no subrostral

teeth 9

9(8) Rostrum shorter than eye Trachypeneus

Rostrum longer than eye Xiphopeneus

10(2) Rostrum usually with ventral teeth and shallowly

compressed Penaeus

Rostrum without ventral teeth and broadly

compressed 11

11(10) Pterygostomian spine present 12

Figure 6.— Penaeid myses: a, Parapenaeus, Mysis I; Pterygostomian spine absent 13

6, Penaeus, Mysis I; c, Sicyonia, Mysis I; d, Solenocera,

Mysis I; e, Trachypeneus, Mysis I; /, Xiphopeneus, 3 Early Xiphopeneus postlarvae probably fall in the <6.0-mm. category,

Mysis I . but none in this size range was noted during the study.

PENEIDAE OF THE NORTHWESTERN GULF OF MEXICO

12(11) Antennules flattened; cervical sulcus present;
sixth abdominal segment short and slightly

curved Solenocera

Antennules round ; cervical sulcus absent ; sixth ab-
dominal segment long and straight, .Parapenaeus

13(11) Rostrum longer than eye Xiphopeneus

Rostrum shorter than eye 14

14(13) First abdominal segment with anteromedian
spine on dorsal surface; sixth abdominal segment

short Sicyonia

First abdominal segment without anteromedian
spine on dorsal surface; sixth abdominal segment
elongate Trachypeneus

Figure 7. — Penaeid postlarvae: a, Parapenatus postlarva, 8.0 mm.; b, Penaeus postlarva, 6.0 mm.; c, Penaeus postlarva,
15.0 mm.; d, Sicyonia postlarva, 5.0 mm.; e, Sicyonia postlarva, 14.0 mm.;/, Solenocera postlarva, 7.0 mm.; g, Trachy-
peneus postlarva, 6.0 mm.; h, Trachypeneus postlarva, 10.0 mm.; i, Trachypeneus postlarva, 25.0 mm.; j, Xiphopeneus
postlarva, 6.0 mm.; k, Xiphopeneus postlarva, 7.5 mm.; m, Xiphopeneus postlarva, 12.0 mm.; I, Tip of telson.

444

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446

U.S. FISH AND WILDLIFE SERVICE

ACKNOWLEDGMENT

Ray S. Wheeler and Robert F. Temple offered
many helpful suggestions during the course of this
study, and Daniel Patlan assisted with the
drawings.

BIBLIOGRAPHY

Anderson, William W., and Milton J. Lindner.

1945. A provisional key to the shrimps of the family

Penaeidae with especial reference to American

forms. Transactions of the American Fisheries

Society, vol. 73, for the year 1943, pp. 284-319.

Berkeley, Alfreda A.

1930. The post-embryonic development of the com-
mon Pandalids of British Columbia. Contribu-
tions to Canadian Biology and Fisheries, being
Studies from the Biological Stations of Canada,
N.S., vol. 6, No. 6, pp. 81-163.
Broad, Alfred Carter.

1957. The relationship between diet and larval
development of Palaemoneles. Biological Bulletin,
vol. 112, No. 2, pp. 162-170.
Brooks, W. K.

1882. Lucifer: a study in morphology. Philosoph-
ical Transactions of the Royal Society, vol. 173,
pp. 57-137.
Dobkin, Sheldon.

1961. Early developmental stages of pink shrimp,
Penaeus duorarum, from Florida Waters. U.S.
Fish and Wildlife Service, Fishery Bulletin 190,
vol. 61, pp. 321-349.
Gurney, Robert.

1924. Crustacea. Part 9-Decapod Larvae. Brit-
ish Antarctic ("Terra Nova") Expedition, 1910.
Natural History Report, Zoology, vol. 8, No. 2,
pp. 37-202.
1943. The larval development of two penaeid prawns
from Bermuda of the genera Sicyonia and Pe-
naeopsis. Proceedings of the Zoological Society of
London, series B, vol. 113, pp. 1-16.
1960. Bibliography of the larvae of Decapod Crus-

tacea [and] Larvae of Decapod Crustacea. [Au-
thorized reprints.] II. K. Engelmann, Weinheim,
429 pp. Original: Ray Society, London, No. 125,
1939; No. 129, 1942.
Heldt, Jeanne H.

1938. La reproduction chez les Crustaces D6capodes
de la famille des Pe.ne.ides. Annates de l'lnstitut
Oceanographique de Monaco, vol. 18 (fasc. 2) pp
31-206.

Hildebrand, Henry H.

1954. A study of the fauna of the brown shrimp
(Penaeus azlecus, Ives) grounds in the western Gulf
of Mexico. Publications of the Institute of Marine
Science, University of Texas, vol. 3, No. 2, pp.
231-366.

Hudinaga, Motosaku.

1942. Reproduction, development and rearing of
Penaeus japonicus Bate. Japanese Journal of
Zoology, vol. 10, No. 2, pp. 305-393, 46 plates.
Tokyo.

Pearson, John C.

1939. The early life histories of some American
Penaeidae, chiefly the commercial shrimp, Penaeus
setiferus (Linn.). Bulletin of the U.S. Bureau of
Fisheries, Bulletin No. 30, vol. 49, pp. 1-73.

Renfro, William C, and Harry L. Cook.

1963. Early larval stages of the seabob, Xiphopeneus
krjyeri (Heller). U.S. Fish and Wildfife Service,
Fishery Bulletin, vol. 63, No. 1, pp. 165-177.

Voss, Gilbert L.

1955. A key to the commerical and potentially
commercial shrimp of the family Penaeidae of the
western North Atlantic and Gulf of Mexico.
Florida State Board of Conservation, Technical
Series No. 14, pp. 1-23.

Williams, Austin B.

1953. Identification of juvenile shrimp (Penaeidae)
in North Carolina. Journal of the Elisha Mitchell
Scientific Society, vol. 69, No. 2, pp. 156-160.

1959. Spotted and brown shrimp postlarvae (Pe-
naeus) in North Carolina. Bulletin of Marine
Science of the Gulf and Carribean, vol. 9, No. 3,
pp. 281-290.

PENEIDAE OF THE NORTHWESTERN GULF OF MEXICO

447

MIGRATIONS AND GEOGRAPHIC DISTRIBUTION OF PINK SHRIMP,
PENAEUS DUORARUM, OF THE TORTUGAS AND SANIBEL GROUNDS,
FLORIDA '

By T. J. Costello and Donald M. Allen, Fishery Biologists {Research)
Bureau of Commercial Fisheries Biological Field Station, Miami, Fla.

ABSTRACT

Pink shrimp, Penaeus duorarum, frequent the estua-
rine waters of south Florida as juveniles. As adults,
they support valuable fisheries on the offshore Tortugas
and Sanibel trawling grounds in the Gulf of Mexico.
To study the Tortugas and Sanibel shrimp stocks as
biological units, 15 mark-recovery experiments in which
biological stains were the marking agents were made.
These experiments (1) indicated timing and direction
of shrimp migrations; (2) delineated estuarine nursery
grounds; and (3) outlined geographic ranges of Tortugas
and Sanibel shrimp stocks.

Prior to migrating offshore, the length of time spent
by juvenile pink shrimp in the nursery areas varies from
about 2 to at least 6 months. In migrating from nursery
areas, some shrimp travel at least 150 miles (nautical)
before recovery on the offshore grounds. Although
migration routes are broad, shrimp emanating from
particular sections of the nursery grounds demonstrate
distinct distributional patterns on the offshore grounds.

The nursery grounds of the Tortugas shrimp stocks
include Florida Bay and estuaries extending at least
as far north as Indian Key on the southwest coast of
Florida. The nursery grounds of the Sanibel shrimp
stocks are confined to the southwest coast of Florida
and include estuaries extending at least from Indian
Key north to Pine Island Sound.

The geographic ranges of the Tortugas and Sanibel
pink shrimp stocks overlap in the nursery areas near
Indian Key and in the offshore water between the two
trawling grounds. Apparently, Tortugas shrimp do
not migrate to the Sanibel grounds and migration from
the Sanibel to the Tortugas grounds is minimal.
The geographic distributions depicted may constitute
minimums for two reasons: First, the absence of fishing
effort in certain contiguous areas prevented observations
which could extend the known distribution. Second,
larval and postlarval pink shrimp may migrate to or
from areas beyond the ranges frequented by Tortugas
and Sanibel shrimp as juveniles and adults.

The migrations and geographic distribution of
pink shrimp, Penaeus duorarum, supporting com-
mercial shrimp fisheries on the Tortugas and
Sanibel grounds, have not been described pre-
viously. These two fisheries, located in the Gulf
of Mexico off the southwest coast of Florida,
provide a total shrimp catch of about 18 million
pounds (heads on) annually. Knowledge of pink
shrimp movement and distribution both on and off
the grounds will contribute to a more thorough

1 Contribution No. 193. Bureau of Commercial Fisheries Biological
Laboratory, Galveston, Tex.

Note.— Approved for publication Sept. 29, 1964.

FISHERY BULLETIN: VOLUME 65, NO. 2
774-711 O— 66 11

understanding of this animal's biology and serve
as a basis for management of this resource.

The catch on the Tortugas and Sanibel grounds
consists primarily of maturing and adult pink
shrimp. This species has a life history similar to
other members of the genus Pevaeus. As adults,
the female pink shrimp extrude eggs in offshore
waters. After hatching, the young shrimp pass
through larval and into postlarval stages as they
move toward the coast. Coastal shallows and
estuaries, utilized as nursery grounds, furnish an
ecological environment considered necessary for
these shrimp during the early stages of their
development. The shrimp gradually move off-

449

shore while maturing. The larger individuals
eventually occupy the deeper waters (Iversen,
Jones, and Idyll, 1960).

To study the Tortugas and Sanibel pink shrimp
stocks as biological units, we must define the
areas supporting these populations (or this popu-
lation). This definition requires delineation of the
shallows and estuaries that sustain young pink
shrimp before they migrate to the Tortugas or
Sanibel grounds, as well as the deeper, offshore
waters frequented by the adult shrimp.

The extensive shallow waters surrounding and
penetrating the southern portion of peninsular
Florida and the adjoining Florida Keys support
an abundance of juvenile pink shrimp, some of
which are captured and sold as bait (fig. 1).
Florida Bay, lying between the southern tip of
Florida and the Florida Keys, is considered an
important nursery area supplying pink shrimp to
the Tortugas grounds (Iversen and Idyll, 1960).
These nursery grounds may extend southwestward
into the grassy shallows west of Marquesas Keys
(Ingle, Eldred, Jones, and Hutton, 1959). Broad
(1950) notes that "ample nursery grounds are to
be found on the Florida west coast between Cape
Sable and Cape Romano where the coastline is
broken by numerous bays, creeks and rivers."

Maturing and adult pink shrimp are found in
most offshore waters adjacent to south Florida,
sometimes in depths of 60 fathoms 2 (Bureau of
Commercial Fisheries, 1961 and 1962). On the

HAWK CHANNEL GROUNDS '

bi'oo' ^> etroo'

Florida shelf, however, much of the bottom is too
rough for conventional trawling gear. South of
lat. 27°00' N., the region under discussion, large
pink shrimp are generally taken commercially
only on the Sanibel, Tortugas, and Hawk Channel
grounds where relatively smooth bottom can be
found. Pink shrimp are fished commercially to a
maximum depth of about 33 fathoms. The
greater depths of the Straits of Florida, to the
south and east of the Tortugas grounds, and the
Gulf of Mexico, to the west, may serve as barriers
to the migration of juvenile and adult pink shrimp.

In 1958, a total of 1,157 pink shrimp were
tagged with Petersen disks and released near
Flamingo in Everglades National Park. From
this group, 1 tagged shrimp was recovered on the
Tortugas grounds (Iversen and Idyll, 1960).
Prior to this recovery no direct evidence linked
small pink shrimp from south Florida estuaries to
those larger shrimp supporting offshore fisheries.
In addition, the relationship of pink shrimp
occurring on the Hawk Channel and Sanibel
grounds to the Tortugas pink shrimp was un-
known. In 1958, the Bureau of Commercial
Fisheries began a series of mark-recovery ex-
periments in the waters of south Florida. One
result of these experiments has been to demon-
strate that certain shallow coastal waters are im-
portant contributors of recruits to the Tortugas
and Sanibel shrimp fisheries. These experiments
also outlined much of the range of the Tortugas
and Sanibel pink shrimp stocks.

In studying pink shrimp, we were also con-
cerned with the incidence of similar species that
might be mistaken for pink shrimp. Two species
closely related to pink shrimp have been reported
from the waters of south Florida. These are
Penaeus brasiliensi? (Eldred, 1960) and Pentu us
azteeus (Burkenroad, 1939; Tabb ami Manning,
1961; Bureau of Commercial Fisheries, 1961).
In Biscayne Bay and Hawk Channel, a relatively
small number of P. brasiliensis were marked and
released with P. duorarum. P. brasiliensis has
not been noted from the Tortugas or Sanibel
grounds despite examination of many shrimp
from these areas. Two specimens of P. aztecus
have been recorded from the northwest portion of
the Sanibel grounds, but none from the Tortugas
grounds.

Figure 1. — Distribution of pink shrimp in the waters of
south Florida.

3 On" the western edge of the Oreat Bahama Bank pink shrimp have been
fomul in depths up to 200 fathoms (Bureau of Commercial Fisheries. 1961).

450

U.S. FISH AND WILDLIFE SERVICE

PROCEDURE

Design of Experiments

The experimental plan was based on the assump-
tion that nursery grounds that furnish recruits to
Tortugas and Sanibel pink shrimp populations are
located in the estuaries and shallow marine waters
of south Florida. To delineate these nursery
areas and relate them to specific offshore shrimp-
ing grounds, young shrimp at selected coastal
sites were captured, marked, and released near
the point of original capture. Recovery of these
marked shrimp on the Tortugas or Sanibel grounds
established the affiliation of shrimp from a nursery
area to those on the offshore grounds.

Inshore release sites were selected geographically
near centers of juvenile shrimp abundance. At
several of the selected locations, juvenile pink
shrimp are plentiful only seasonally. Therefore,
to obtain sufficient shrimp for marking, timing of
inshore releases necessarily coincided with these
estuarine peaks of abundance. Proceeding with
marked shrimp releases according to these criteria,
we established the affiliation of shrimp from
shallow water areas along an extensive expanse of
coastline to the offshore grounds.

Three offshore mark-recovery experiments, de-
signed primarily to determine growth and mortal-
ity rates, also furnished information concerning
migration and distribution of the larger pink
shrimp.

Marked shrimp, which form the basis of this
report, were stain-marked by injection of biological
stains (Menzel), 1955; Dawson, 1957; Costello,
1964).

Recovery of Stained Shrimp

Shrimp fishermen and packers were informed of
the purpose of mark-recovery experiments prior to
each release of stain-marked shrimp. Preserved
stain-marked shrimp in glass vials were displayed
and posters describing stain-marked shrimp were
placed in shrimp packing plants. For each
recovery, together with the position, date and
depth of recapture, rewards of from $1 to $5 were
offered at various stages of the program.

Except for four recoveries made by Bureau of
Commercial Fisheries vessels, all 2,201 of the
marked shrimp recoveries which form the basis of
this report were made by commercial fishing
vessels. Inshore recoveries were made by bait

shrimp fishermen in Biscayne Bay, Barnes Sound,
and Florida Bay, and near Indian Key.

Stain-marked shrimp released offshore in or near
areas where shrimp trawlers were active were
caught and returned for reward payments in
surprising numbers. Two groups released on the
Tortugas grounds yielded 1,227 recoveries — 21.1
percent of the first group released and 33.3 percent
of the second group released. On Sanibel, 563
marked shrimp were recovered from a release of
2,496 — a 22.5 percent recovery.

Inshore or estuarine releases were usually in
localities remote from commercial fishing opera-
tions. This is reflected in recovery rates which
averaged less than 1 percent of the numbers
released.

Recovery rates are affected by factors such as
the effective number of marked animals released —
the number returned safely and in good condition
to the environment from which captured. Also
affecting recovery rates are direction of migration,
location and amount of fishing effort, and aware-
ness and interest of industry personnel in a position
to recover marked shrimp. Some or all of these
factors varied during the course of these experi-
ments, and they have been considered in evaluat-
ing the data.

MIGRATIONS

Release and Recovery Sites

Table 1 summarizes pink shrimp mark-recovery
experiments in south Florida waters from 1958 to
1963. Release sites are numbered in chronological
order.

Figure 2 depicts the numbered release sites and
general area of recovery of stain-marked shrimp.
Arrows joining release and recovery sites do not
necessarily indicate routes of migration.

On the southwest coast of Florida, marked
juvenile pink shrimp released in large numbers in
Pine Island Sound (10) migrated to the south and
northwest portions of the Sanibel grounds but not
to the Tortugas grounds. A release southeast of
Sanibel, at Indian Key (14), resulted in recoveries
near Indian Key and on both the Sanibel and
Tortugas grounds. On the southwest coast of
Florida and in Florida Bay, marked juvenile pink
shrimp released near Shark River (6), Flamingo
(2), Bottle Key (9), and Peterson Keys (3) were
recovered in the Tortugas shrimp fishery. Several
shrimp from Bottle Key were also caught in

MIGRATIONS OF FLORIDA PINK SHRIMP

451

80*00'

I EGENO

MARKED SHRIMP
RELEASE SITE

—

P0SS18LE MIGRATION
ROUTE TO RECOVERY
AREA

-y

RECOVERIES NEAR
RELEASE SITE ONLY

Figure 2. — Release-recovery sites of marked pink shrimp
in the waters of south Florida, 1958-63.

Florida Bay near and south of their release site,
and one was recovered about 6 miles 3 north of

'Nautical miles are used in this report.

the northern border of the Tortugas grounds. A
few shrimp released at Bottle Key migrated at
least 150 miles to the western portion of the
Tortugas grounds.

On the southeast coast of Florida, young shrimp
released in Biscayne Bay (1 and 11) and Barnes
Sound (5) were recovered only near their respective
release sites. No recoveries were reported from
one release in Biscayne Bay (8) or from a small
release at Lower Matecumbe Key (4), which
borders eastern Florida Bay.

Migrations of adult shrimp were determined by
releases in the deeper, offshore waters. Although
a release of maturing shrimp on the south Sanibel
grounds (13) resulted in 561 recoveries in the
south Sanibel fishery, only two shrimp migrated
to the Tortugas grounds. Marked shrimp re-
leased on two separate occasions on the Tortugas
grounds near 'C conservation buoy (12 and 15)
apparently remained on or near the Tortugas
grounds. The net movement of recovered indi-
viduals released on the Tortugas grounds was
northwesterly into deeper water. Similar move-
ment has been reported for tagged pink shrimp

Table 1-

-Summary of pink shrimp

mark-recovery experiments in

south Florida waters, 1958-63

Release site

Site
number

Date of release

Released

Area of recovery

Recovered

Period of recovery

Days-out time '

Minimum

Maximum

Mean 3

3
4

7
8
9

13
14
15

1958
Apr. 24-May 29...
Oct. 24-31

Number
19,358
7,264

1,729
1,672

7,084

16,638

6,815
11,000
13.306

32,913

2. 775
2,091

2,496
19.860
2,350

Number
57
4

11
0

18
0
10

149

4
443

561

784

May-July 1958

Number

Number
(')

Tortugas grounds

Jan.- Feb. 1959

Mar .-May 1959. ..

84
46

121
93

1969
Jan. 29

Key.

July 7-16 .

Aug. 1959-Jan.

1960.
Dec. 1959-Mar.

1960.

Mar .-May 1960...

16
35

174
126

160

Nov. 2-6

Tortugas grounds
Tortugas grounds

Hawk Channel

1960
Feb. 4

Bottle Key.-

Nov. 1-4

Nov. 1960-Jan.
1961.

Jan.-May 1961

Jan.-Nov. 1961....
Mar.-May 1961...

May-June 1961....
Sept. -Dec. 1961...

Mar.-Aug. 1962...
July 1962.

72
36
112

34
1

115

89
40

205
331
160

58
85

146

115

229

89
185

106

Pine Island Sound-,

Nov. 29- Dec. 15...

1961
Apr. 18

(Tortugas grounds

fS. Sanibel grounds

\NW. Sanibel grounds.

124
106
135

Tortugas grounds...
Sanibel grounds

Sept. 20-23

196S
Mar. 19-22.. _

Aug. 27-Sept. 5...

Dec. 11-15

Tortugas grounds... .

/Sanibel grounds..

\Tortugas grounds. . .

115

Sept. 1962

S. Sanibel grounds

NW. Sanibel grounds.
iTortugas grounds

Tortugas grounds

Oct. 1962-Apr.

1963.
Nov. 1962

159

Oct. 1962-Mar.

1963
Dec. 1962-Mar.

1963.

128
21

Total

147, 351

2,201

1 Calculated from the mean release date.

- Calculated from all recoveries.

3 Widespread of release dates at site number 1 negates value of "days-out time" data.

452

I .S. FISH \\1> WILDLIFE Skin 1(1.

released and recovered on the Tortugas grounds
(Iversen and Jones, 1961). Another offshore
release of stain-marked shrimp in Hawk Channel
(7), south of Bahia Honda Key, yielded recoveries
on the Tortugas grounds.

Areal Distribution

In figure 2 lines connecting release and recovery
sites suggest possible migration routes traversed
by pink shrimp en route to the Tortugas or
Sanibel grounds. Actual routes of migration are
not known because of the few recoveries in inter-
vening areas which receive limited fishing effort.
One exception pertains to the inshore leg of the
route followed by shrimp released near Bottle
Key as they moved toward the Tortugas grounds.
From this group, a bait shrimp fisherman re-
covered 10 marked shrimp in Florida Bay 22 to 80
days after release. Of these 10, 7 were found
near the release site, and 3 had moved southwest
of Bottle Key toward a pass breaching the Florida
Keys. Higman (1952) reported large catches of
shrimp at such passes on night tides flowing from
Florida Bay to the Atlantic Ocean. Undoubtedly,
many shrimp from Florida Bay move into Hawk
Channel, and we have now established that shrimp
from the Hawk Channel grounds south of Bahia
Honda Key migrate to the Tortugas grounds.
Such movement was suggested by Costello and
Allen (1960).

The distribution of recoveries from individual
releases shows that migration routes may be broad
and that shrimp disperse considerably while mi-
grating. For example, shrimp released at Indian
Key have been recovered at points as far as 125
miles apart. When there is a protracted departure
time from a release site, such as occurred at Bottle
Key (table 1), separate elements of the marked
group may be subjected to a diverse environment
(temperature, salinity, tides, currents) that could
affect the direction of migration.

On the Tortugas grounds, the size of pink shrimp
increases with the depth (Iversen, Jones, and Idyll,
1960). In general, mark-recovery experiments
also indicate that pink shrimp move into deeper
water as they increase in size. Thus, from exam-
ining the depth contours, we would expect that the
majority of recruits enter the Tortugas and Sani-
bel grounds from the shallower waters northeast,
east, or southeast of the grounds. On the Tortu-
gas grounds the recovery patterns of marked

6uiF ^e-;

ofr SW1IBEL 6«tOUM

INC'liK IEIC "

IE XIC0

LEGEND

RELEASE SITES

SANIBEL GROUNDS

: .

INDIAN MET

BOTTLE KEY

HAWK CHANNEL GROUNDS

TORTUGAS RECOVERY SITES

• ■ • A

m o< ipM MIMMi 'n*<a* M\

Figdre 3. — Distribution of recoveries of pink shrimp on the
Tortugas grounds from four release sites.

shrimp from a common release area suggest the
directions from which the shrimp enter the
grounds. Reference is made to figure 3, which
illustrates the recovery positions on the Tortugas
grounds of shrimp liberated at four release sites
Because of varied fishing effort, the actual distribu-
tional pattern of marked individuals on the
grounds may differ somewhat from that suggested
by the recoveries. The greatest concentration of
fishing pressure occurs in the northeast quadrant of
the grounds followed, in descending order, by the
northwest, southwest, and southeast quadrants.
Fishing pressure in the southeast quadrant is
minimal and probably few recoveries should be
expected from there. Bearing these qualifications
in mind and by inspecting figures 2 and 3, we made
the following observations:

1. Recoveries of shrimp migrating from the
Sanibel grounds (13) were confined to the north-
west quadrant of the Tortugas grounds, suggesting
entrance from the north.

2. Recoveries of shrimp migrating from Indian
Key (14) were distributed within the northwest
and northeast quadrants of the Tortugas grounds,
indicating entrance from the north and northeast.

3. Recovery positions of shrimp migrating
from Bottle Key (9) were concentrated in the
northeastern and west central portions of the
grounds. This recovery pattern may be dis-
torted by the limited fishing effort in the southeast
quadrant. Thus, indications are that Bottle

MIGRATIONS OF FLORIDA PINK SHRIMP

453

Key shrimp entered the Tortugas grounds from
the east, and, perhaps, northeast and southeast.

4. Shrimp that migrated from Hawk Channel
(7) were concentrated along the southern border
and in the west central section of the Tortugas
grounds. Once again, the distributional pattern
may be distorted by limited fishing effort in the
southeast quadrant. It appears, however, that
Hawk Channel shrimp entered the grounds from
the southeast.

On the south Sanibel grounds, distribution of
the first 23 recoveries of marked shrimp released
in Pine Island Sound indicates that these shrimp
entered the grounds from the shallower waters to
the northeast and east (fig. 4). A comparison
of the distributional pattern of the last 23 re-
coveries with that of the first 23 indicates the
general trend of movement was into deeper water,
or southwestward on the south Sanibel grounds.

TIME DISTRIBUTION

The period of tune expended by pink shrimp
(1) on nursery grounds, (2) while traversing mi-
gration routes, and (3) on the offshore grounds can
be approximated in some cases from the number
of days elapsing between release and recovery of
marked shrimp, or "days out time" (table 1).
Recovery frequencies for half-month periods on

V = RELEASE DATE

Figure 4. — Distribution of recoveries of pink shrimp on
Ilic south Sanibel grounds from releases in Pine Island
Sound.

454

MHIM KET ly-

,„,..,„_. 17~n , ,

SMISEl

IIHU RET iy-

5H1R» u.vEH

FLll'NCO

BOTTLE IET it

„-xmmvmm~

PETERKM Kit >\-

H»I CHANNEL |3

-H-r-*

1 1 ' 1

1 1

i , |V . i ,iMf

V \ l'"|

Figure 5. — Time-frequency distribution of marked shrimp
recoveries on the Tortugas and Sanibel grounds by one-
half-month periods.

the Tortugas and Sanibel grounds (fig. 5) indicate
periods of availability of marked shrimp from
various release sites. Caution in interpreting
these data is necessary since not all shrimp of a
marked group depart the release areas at the
the same time, are recovered immediately upon
reaching the offshore grounds, or are recovered
in proportion to their relative abundance.

A few pink shrimp that were marked and re-
leased in Barnes Sound (5) remained in the
Sound for at least 174 days. Following the pink
shrimp age-size relation given by Kutkuhn,4
we estimated the smallest shrimp released,
16.0 mm. carapace length (75.0 mm. total length),
to be about 60 days old. If 21-28 days are allowed
for larval and early postlarval development prior
to entrance into the nursery grounds, then it
appears that under certain conditions more
than 6 months of life may be spent in the estuaries.
Conversely, time spent in the estuaries may be
relatively brief. Only 35 days after the Shark
River release (6), one marked male, 20.2 mm.
carapace length (94.8 mm. total, length), was
recovered on the Tortugas grounds. Estimating
this shrimp's age as 79 days and subtracting
pre-estuarine entrance time, we found it ap-
parently spent less than 2 months in the estuarine
environment. The occurrence of pink shrimp
less than 20.0 mm. carapace length (92.5 mm.
total length) on the Tortugas grounds may indi-
cate that some individuals spent little or no time
on the more distant estuarine nursery grounds.

' Kutkuhn. Joseph H„ Dynamics of a peimelil shrimp population and
management implications, p. 313, loc. dt.

U.S. FISH AND WILDLIFE SERVICE

Marked shrimp from the Bottle Key release (9),
made in November 1960, were recovered in Florida
Bay up to 80 days after release. One marked
shrimp was recovered in the Bay after two other
Bottle Key shrimp had already been caught on
the Tortugas grounds. These recoveries show
clearly that not all members of a given group of
shrimp depart the estuaries at the same time.
Bottle Key shrimp were recovered on the Tortugas
grounds from January through May 1961 (fig. 5).
The majority, however, were taken between Jan-
uary 16 and March 31, indicating that most of
the marked Bottle Key shrimp that reached the
Tortugas grounds were available for recapture
within 75 to 149 days after release. The straight
line distance between Bottle Key and 'C con-
servation buoy, located near the center of fishing
effort on the Tortugas grounds, is about 100 miles.
Stained shrimp released in September 1961 (12)
and December 1962 (15), near 'C buoy on the
Tortugas grounds, were recovered up to 85 and 106
days after release, respectively. During these
periods, many had moved west or northwest into
deeper water, some as far as 35 miles. Although
several shrimp from release site 15 were taken just
south of the northern border of the Tortugas
grounds, none was recovered off the Tortugas
grounds (fig. 6).

Marked shrimp released in Pine Island Sound
(10) in November and December 1960, were re-

/\ RECOVERY LIMITS
^s aftfh infi nfl«

AFTER 106 DATS

Figure 6. — Dispersal of marked pink shrimp on the
Tortugas grounds, December 1962 through March 1963.

covered on the Sanibel grounds from January
through November 1961 . The center of the south
Sanibel grounds is about 22 miles from the release
site. The greatest numbers are recovered between
February 1 and May 15. Part of the increase
during this period, however, may be a reflection
of increased fishing effort. One shrimp was re-
covered on the Sanibel grounds about 11 months
after release. Since the smallest shrimp released
was estimated to have been at least 1 month old,
the recovered shrimp must have been at least a
year old.

Marked pink shrimp released on the south Sani-
bel grounds (13) in March 1962 were caught there
up to 146 days after release. The recovery posi-
tions indicated gradual movement into deeper
water to the west and southwest. After 115 days
two marked shrimp were caught on the north-
western Tortugas grounds, about 80 miles distant.

GEOGRAPHIC RANGE OF THE TORTUGAS AND
SANIBEL PINK SHRIMP

The range and relationship of pink shrimp stocks
of the Tortugas and Sanibel grounds were demon-
strated by mark-recovery experiments. The Tor-
tugas stocks of pink shrimp are defined as those
pink shrimp that are available for capture on the
Tortugas shrimp trawling grounds during some
portion of their life. The Sanibel stocks may be
similarly defined by appropriate word substitu-
tion. The sources of pink shrimp eggs and larvae
that perpetuate these fisheries have not been
positively established. Much of the area fre-
quented by Tortugas (or Sanibel) pink shrimp as
juveniles and adults, however, can be determined
by inspection of marked shrimp release-recovery
information (fig. 2 and table 1), Figure 7 is pro-
visional and probably depicts only the minimum
ranges of the Tortugas and Sanibel pink shrimp
stocks.

Tortugas Stocks

The Tortugas trawling grounds, located north-
west, west, and southwest of Key West, have a
maximum depth of about 33 fathoms. The
"boundary" is rather indefinite and encloses
about 3,100 square miles. In much of the area
trawling is restricted by rough bottom or extreme
shallowness.

North, northeast, and east of the Tortugas
grounds, the Tortugas stocks of pink shrimp

MIGRATIONS OF FLORIDA PINK SHRIMP

455

Figure 7. — Provisional ranges of Tortugas and south
Sanibel pink shrimp stocks.

frequent an area extending at least to release sites
13, 14, 6, 2, 9, 3, and 7 (fig. 2). From the south
section of the Sanibel grounds (13), two marked
shrimp moved southward to the northwest portion
of the Tortugas trawling area, establishing a
degree of affiliation between these two fisheries.
Because many juvenile shrimp released in Pine
Island Sound (10) migrated to the Sanibel shrimp
fishery, the relationship of Pine Island Sound
shrimp to the Tortugas stocks is also indicated.
A total of 35,409 marked shrimp released on Sani-
bel and in Pine Island Sound, however, yielded 716
recoveries in the Sanibel fishery and only two
recoveries to the south, on the Tortugas grounds.
Therefore, contribution of shrimp from these two
northern sites to the Tortugas fishery must be
considered minimal.

Indian Key (14) is about 55 miles southeast of
Pine Island Sound. Juvenile pink shrimp from
Indian Key are definitely affiliated with the
Tortugas stocks, although almost three times as
many marked shrimp released at Indian Key were
recovered on the Sanibel grounds as on the Tortu-
gas grounds. Analysis of recoveries from release
sites 10, 14, and 6 suggests that the northward
distribution of Tortugas pink shrimp along the
Florida west coast ends north of Indian Key.

Southward from Indian Key to Shark River (6),
Flamingo (2), and the Whitewater Bay-Florida
Bay complex, we found the northeasterly penetra-
tion of the Tortugas pink shrimp stocks restricted

by the land mass of the Florida peninsula, not by
the coastline. For the Whitewater Bay drainage
area, Tabb, Dubrow, and Jones (1962) presented
evidence linking juvenile shrimp from estuaries
upstream (inland) to the Tortugas population and
to coastal release sites proven to be Tortugas
affiliated.

The Tortugas pink shrimp recruitment range
extends eastward at least to Bottle Key (9) and
probably ends at the periphery of northeastern
Florida Bay. Evaluation of the results of releases
6, 2, 9, 3, and 7 strongly indicates that all of Florida
Bay provides recruits to the Tortugas fishery.
Evidence that a separation of stocks may occur
between Bottle Key and Barnes Sound (5) is
indicated by the fact that considerably more
marked shrimp were released in the Tortugas non-
contributing areas northeast of Bottle Key than
in the adjacent contributing areas to the south-
west. A total of 40,217 marked shrimp was re-
leased in Biscayne Bay (1, 8, and 11) and Barnes
Sound as compared to a total of 15,035 released
near Peterson Keys (3) and Bottle Key. Re-
coveries in Barnes Sound were particularly
interesting, because some marked shrimp were
recovered near the release site more than 5)i
months after release. The Biscayne Bay and
Barnes Sound releases, however, occurred in late
spring and summer, while the Peterson Keys and
Bottle Key releases occurred in late fall and winter.
The possibility cannot be discounted that migra-
tion patterns and, therefore, stock distribution
may vary seasonally. More definitive results
might be obtained from releases in both areas
during the same season. However, marked
shrimp releases at Bottle Key could not be
seasonally timed to coincide with the prior release
in Barnes Sound because pink shrimp occur in
sparse quantities in northeastern Florida Bay
during the summer.

The negative results of the Lower Matecumbe
Key release (4) can possibly be attributed to a
separation of stocks in that area, but are more
likely a reflection of the relatively few (1,672)
marked individuals released.

In the offshore waters east of the Tortugas
grounds, the Tortugas pink shrimp recruitment
range extends at least to that part of Hawk
Channel (7) south of Bahia Honda Key. How-
ever, if shrimp from the Peterson Keys-Bottle
Key area are found to use the adjacent Hawk

456

U.S. FISH AND WILDLIFE SERVICE

Channel as a route to the Tortugas grounds
(migrations), the known limit of the Tortugas
population would be extended northeastward on
the Atlantic side of the Keys.

South, southeast, and east of Hawk Channel,
pink shrimp have been caught in the Straits of
Florida in depths to 60 fathoms (Bureau of Com-
mercial Fisheries, 1961 and 1962). South of the
Tortugas trawling grounds, pink shrimp have been
taken in depths to 37 fathoms (Springer and
Bullis, 1954). At these depths, however, pink
shrimp have not been found abundant. The rela-
tionship of these "deep water" shrimp to those
inhabiting the relatively shallow water of the
Tortugas grounds has not been determined.

Sanibel Stocks

The Sanibel grounds comprise two distinct areas
of trawlable bottom and are located northwest
and south of Sanibel Island. Most trawling is
confined to depths of less than 10 fathoms The
southern boundary of the south Sanibel grounds
is about 50 miles north of the Tortugas northern
boundary (fig. 1). The northwest portion of the
Sanibel shrimp grounds represents the southern
extremity of a sporadic, undefined pink shrimp
fishery which parallels a large portion of the
Florida west coast.

Recoveries of marked shrimp reveal that Pine
Island Sound serves as a nursery ground for both
sections of the Sanibel grounds.

In this discussion the two Sanibel areas will be
treated separately since there are indications that
the northwest Sanibel grounds may support stocks
of pink shrimp differing from those of the south
Sanibel grounds. This is suggested by the fact
that while 2,496 marked shrimp were released on
south Sanibel (13), and 563 recovered there, none
was recovered on northwest Sanibel despite mod-
erate fishing effort in the latter area. One marked
shrimp, however, from the Indian Key release (14)
was recovered in the northwest Sanibel fishery.
This shrimp very likely passed through the south
Sanibel grounds en route to northwest Sanibel,
linking all three areas. These apparently con-
tradictory results may indicate that movement of
shrimp from the southeast to northwest Sanibel
is seasonal or sporadic. Because no marked
shrimp have been released on northwest Sanibel,
the relationship of shrimp from this area to shrimp
stocks to the south is unknown.

The coastal distribution of shrimp recruited to
the south Sanibel fishery extends from at least
Pine Island Sound (10) to Indian Key (14). Juve-
nile shrimp recruited to the south Sanibel fishery
probably issue from estuaries between and in-
cluding these release sites. Since 22 of the marked
shrimp released at Indian Key were recovered on
the south Sanibel grounds, as compared with 8
on the Tortugas grounds, the southeastern limits
of the south Sanibel shrimp population probably
lie south of Indian Key but north of Shark River.
The latter point is emphasized by the fact that
releases of 16,638 marked shrimp at Shark River
and 23,971 in Florida Bay have resulted in numer-
ous recoveries on the Tortugas grounds but none
on the Sanibel grounds.

The distribution of recoveries from coastal and
offshore releases provides good evidence that the
Tortugas and Sanibel shrimp stocks overlap in
the general area of Indian Key (14) and offshore,
between the Tortugas and Sanibel grounds. Two
stain-marked shrimp, mentioned previously, mi-
grated from the Sanibel to the Tortugas grounds,
apparently crossing the intervening area. The
bottom in this area is rough and usually precludes
successful trawling with conventional shrimping
gear. Despite low fishing effort in the area, two
pink shrimp tagged and released on the Tortugas
grounds were recovered 11 and 14 miles north of
the present northern border of the Tortugas
grounds (Iversen and Jones, 1961). In addition,
one stain-marked shrimp from the Bottle Key
release was recovered 6 miles north of the Tortugas
border (fig. 3). There is no evidence, however,
of migration from the Tortugas to the Sanibel
grounds. Of 4,441 stain-marked shrimp released
on the Tortugas grounds, none was recovered on
or near Sanibel grounds. Because the movement
of pink shrimp is generally into deeper water,
migration from the Tortugas grounds to the
shallower Sanibel grounds seems unlikely.

SUMMARY AND CONCLUSIONS

1. In south Florida, mark-recovery experiments
with biological stains as the marking agents
demonstrated the importance of certain shallow
coastal waters as nursery grounds for pink shrimp
that eventually frequent the offshore Tortugas
and Sanibel grounds.

2. Some shrimp from shallow coastal waters

MIGRATIONS OF FLORIDA PINK SHRIMP

457

migrated at least 150 miles before recovery on the
offshore grounds.

3. The recovery patterns show that shrimp
disperse considerably between release and re-
covery, suggesting broad migration routes. De-
spite such dispersion, shrimp emanating from each
nursery area indicated a distinct pattern of
distribution on the offshore grounds.

4. Shrimp leaving the estuaries and moving
across the offshore grounds tend to move into
deeper water. Although limited movement into
shallower water was noted on the offshore grounds,
such movement is apparently only temporary,
because recoveries after long free periods were
almost always from deeper water.

5. Mark-recovery data reveal that the length of
time spent in the estuaries by shrimp may vary
from about 2 to at least 6 months.

6. Between release in an estuary and recovery
on an offshore trawling ground the minimum free
time of any marked shrimp was 35 days, the
maximum 331 days.

7. Shrimp available for capture on the Tortugas
trawling grounds emanate from shallower waters
to the north, northeast, and east of the grounds.
In these directions, the Tortugas stock recruit-
ment range extends at least as far as the south
Sanibel grounds, Indian Key, Shark River,
Flamingo, Bottle Key, Peterson Keys, and that
portion of Hawk Channel south of Bahia Honda
Key. Thus, a large portion of the estuarine
nursery grounds is located within Everglades
National Park. Shallows within the Tortugas
grounds may also be a source of recruits to this
fishery. The affinity to the Tortugas stocks of
pink shrimp occurring in deep water east and south
of -the Florida Keys, and south, west, and north-
west of the Tortugas grounds has not been
established.

8. Shrimp available for capture on the south
Sanibel trawling grounds emanate from shallower
waters along the adjacent coast. Coastally,
minimum limits of the recruitment area range
from Pine Island Sound, to the north, to Indian
Key, southeast of the grounds. Offshore, pink
shrimp of the south Sanibel stocks occur on the
northwest Sanibel grounds and on the northwestern
portion of t lie Tortugas grounds. The relationship
of the south Sanibel pink shrimp to those in-
habiting deeper water west of the grounds is not
known.

9. The Sanibel and Tortugas stocks overlap
along the southwest coast of Florida and in the
offshore water between the two trawling grounds.
There is evidence that young shrimp recruited
from nursery grounds as remote as northeastern
Florida Bay and Pine Island Sound associate, as
adults, in the area intervening between the
Sanibel and Tortugas grounds. Apparently Tor-
tugas shrimp do not migrate to the Sanibel
trawling grounds, and south Sanibel shrimp seldom
migrate to the Tortugas trawling grounds, or
to the northwest Sanibel grounds.

10. The geographic distribution of the Tor-
tugas and Sanibel shrimp stocks as presented here
constitutes a minimum range. The absence of
fishing effort in certain contiguous regions pre-
cluded recoveries and, therefore, identification of
these regions as part of the range. In addition,
insufficient knowledge of the migrations of larval
and postlarval shrimp precludes determination of
their origin, which may be beyond the region
known to be frequented by the Tortugas and
Sanibel shrimp stocks as juveniles and adults.

LITERATURE CITED

Broad, Carter.

1950. The shrimp fishery of the Florida Keys.
University of North Carolina Institute of Fisheries
Research, Morehead City, N.C., March 15, 1950.
[Mimeographed Report, 13 pp.]

Bureau of Commercial Fisheries.

1961. Extensive survey made off Florida east coast
for stocks of shrimp and scallops: M/V Silver Bay
Cruise 26. U.S. Fish and Wildlife Service, Com-
mercial Fisheries Review, vol. 23, No. 1, pp. 32-34.

1962. Exploratory fishing for shrimp, scallops, and
small snappers in south Atlantic: M/V Silver Bay
Cruise 34. U.S. Fish and Wildlife Service, Com-
mercial Fisheries Review, vol. 24, No. 1, pp. 29-31.

Burkenroad, Martin D.

1939. Further observations on Penaeidae of the
northern Gulf of Mexico. Bingham Oceanographic
Collection, Bulletin, vol. 6. art. 6, 62 pp.

COSTELLO, T. J.

1964. Field techniques for staining-recapture experi-
ments with commercial shrimp. U.S. Fish and
Wildlife Service, Special Scientific Report — Fish-
eries No. 484, 15 pp.

COSTELLO, T. J., AND DONALD M. AlLKN.

1960. Notes on the migration and growth of pink
shrimp (Penacus rfttorarum). Gulf and Caribbean
Fisheries Institute Proceedings. 12th Annual Ses-
sion, pp. 5-9.

458

U.S. FISH AND WILDLIFE SERVICE

Dawson, C. E.

1957. Studies on the marking of commercial shrimp
with biological stains. U.S. Fish and Wildlife
Service, Special Scientific Report — Fisheries No.
231, 23 pp.

Eldred, Bonnie.

1960. A note on the occurrence of the shrimp,
Penaeus brasiliensis Latreille, in Biscayne Bay,
Florida. Florida Academy of Science, Quarterly
Journal, vol. 23, No. 2, pp. 164-165.

HlGMAN, J. B.

1952. Preliminary investigation of the live bait
shrimp fishery of Florida Bay and the Keys. Re-
port to Florida State Board of Conservation from
The Marine Laboratory, University of Miami, 8 pp.
[Mimeographed.]
Ingle, Robert M., Bonnie Eldred, Hazel Jones, and
Robert F. Hutton.

1959. Preliminary analysis of Tortugas shrimp
sampling data 1957-58. Florida State Board of
Conservation, Technical Series No. 32, 45 pp.

Iversen, Edwin S., and C. P. Idyll.

1960. Aspects of the biology of the Tortugas pink
shrimp, Penaeus duorarum. American Fisheries
Society, Transactions, vol. 89, No. 1, pp. 1-8.

Iversen, E. S., and A. C. Jones.

1961. Growth and migration of the Tortugas pink
shrimp, Penaeus duorarum, and changes in the
catch per unit of effort of the fishery. Florida

State Board of Conservation, Technical Series No.
34, 28 pp.
Iversen, Edwin S., Andrew E. Jones, and C. P. Idyll.

1960. Size distribution of pink shrimp, Penaeus
duorarum, and fleet concentrations on the Tortugas
fishing grounds. U.S. Fish and Wildlife Service,
Special Scientific Report — Fisheries No. 356, 62 pp.

Menzel, R. Winston.

1955. Marking of shrimp. Science, vol. 121, No.
3143, p. 446.
Springer, Stewart, and Harvey R. Bullis, Jr.

1954. Exploratory fishing in the Gulf of Mexico,
summary report for 1952-54. U.S. Fish and Wild-
life Service, Commercial Fisheries Review, vol. 16,
No. 10, pp. 1-16.
Tabb, Durbin C, David L. Dubrow, and Andrew E.
Jones.

1962. Studies on the biology of the pink shrimp,
Penaeus duorarum Burkenroad, in Everglades Na-
tional Park, Florida. Florida State Board of Con-
servation, Technical Series No. 37, 30 pp.
Tabb, Durbin C, and Raymond B. Manning.

1961. A checklist of the flora and fauna of northern
Florida Bay and adjacent brackish waters of the
Florida mainland collected during the period July,
1957 through September, 1960. Bulletin of Marine
Science of the Gulf and Caribbean, vol. 11, No. 4,
pp. 552-649.

MIGRATIONS OF FLORIDA PINK SHRIMP

459

TIME OF MIGRATION AND AGE GROUP STRUCTURE OF SOCKEYE
SALMON (ONCORHYNCHUS NERKA) SPAWNING POPULATIONS IN THE
NAKNEK RIVER SYSTEM, ALASKA »

By Richard R. Straty, Fishery Biologist (Research)
Bureau of Commercial Fisheries Biological Laboratory, Auke Bay, Alaska

ABSTRACT

The annual sockeye salmon (Oncorhynchus nerka)
migration to the Naknek River system, Alaska, was
studied to determine to what extent major spawning,
populations were segregated by their time of occurrence
in the run. The extent of segregation by age in the run
and on the spawning grounds was also studied.

Daily tagging on the Naknek River and subsequent tag
recovery on the spawning grounds showed that segrega-
tion of individual spawning populations by time of
occurrence in the Naknek run is limited. There was a
more or less complete intermingling of most spawning

groups throughout the run; consequently, most spawn-
ing grounds derive their fish from all parts of the run
and, generally, in proportion to the size of the daily
escapement.

Daily escapement age analysis indicated the lack of
marked segregation by age in the Naknek run. No
seasonal trend in age was apparent in the 1962 Naknek
run.

Differences in age characteristics of major spawning
ground populations indicated segregation by age on the
spawning grounds of the Naknek River system.

It is generally accepted that sockeye salmon
(Oncorhynchus nerka), when mature, return to the
river system of their origin to spawn. This
homing tendency was recognized as early as 1738
(Krasheninnkov, 1754) and given formal expres-
sion as the "home-stream" theory in the early
1900's (Chamberlain, 1907). Over a period of
many years, evidence in support of this theory
was obtained from marking experiments in
various river systems from Oregon to Alaska.

The applicability of the "home-stream" theory
to individual spawning areas within a river
system was first suggested by Gilbert (1914-16,
1918-20) in his investigation of the sockeye salmon
of the Fraser River in British Columbia. He
found widely differing scale types on fish from
different parts of the Fraser River system. Sev-

Note. — Approved for publication Oct. 7, 1964.

' Based in part on a thesis submitted to the graduate school of the Uni-
versity of Hawaii, Honolulu, in partial fulfillment of the requirements for the
degree of Master of Science in Zoology, June 1963.

eral areas were characterized by spawning popula-
tions having scale types so radically different as to
permit conclusive segregation of one spawning
population from another. Gilbert concluded that
the appearance in the fishery of fish with the differ-
ent scale types could be used to ascertain changes
in the racial composition of the catch. Since
Gilbert's early work, timing and duration of
abundance of various spawning groups have been
established by tagging experiments (Thompson,
1945; Killick, 1955), and racial identification has
been determined by scale studies (Clutter and
Whitesel, 1956; Henry, 1961).

Studies on the Fraser River and several other
major sockeye salmon systems in North America
have shown that individual spawning populations
tend to be segregated in their time of occurrence in
the run. Each population appears to have its
own specific requirements for survival that
govern the time at which it migrates from the sea.
For a number of river systems this time seems to

FISHERY BULLETIN: VOLUME 65, NO. 2

461

be related to the distance fish must travel to reach
the spawning ground and to the type of spawning
area they use. In general, it seems that sockeye
salmon with the greatest distances to travel occur
in the early part of the run, while those with the
shortest distances occur in the late part. This is
quite evident on the Fraser River and is reported
to occur also on the Copper River in central
Alaska.2

Segregation of spawning groups in time by the
type of spawning area utilized has been reported
in some systems.

Barnaby (1944) found that fish occurring early
in the run populate all the spawning streams
entering Karluk Lake on Kodiak Island, whereas
most of those appearing late in the run use only
the larger streams and lake beaches. Tagging
studies on the Skeena River in British Columbia
(Fisheries Research Board of Canada, 1957)
indicate that sockeye salmon bound for the smaller
tributary streams of Babine Lake pass through the
fishery earlier than those bound for the outlet
spawning grounds.

Seasonal timing may also be related to the age
of fish. Rounsefell (1958) presents evidence that
"the age of downstream migration has a negative
effect on the season of return. The 2-year mi-
grants run first, followed by the 3-, 4-, and finally
the 5-year migrants.3 The ocean age, on the con-
trary, has a positive effect. The 4-ocean fish run
earliest, followed in succession by the 3-, 1-, and
0-ocean fish groups." 4 Similar changes in age
composition during the run were reported for the
Copper River by Thompson.

Segregation of age groups of sockeye salmon by
lake system and by spawning grounds within a
lake system has also been reported in the litera-
ture. Although the 42 age group 6 dominates the
Fraser River run annually, three races — the
Chilko, Taseko, and Birkenhead — are character-

1 Thompson, Seton H. The red salmon (Oncorhynchus nerka) ol Copper
River, Alaska. Bureau of Commercial Fisheries Biological Laboratory,
Auke Bay, Alaska. (Manuscript).

' Refers to the age (figured from time of deposition of the egg) at which the
juvenile salmon migrates from fresh water to the sea. Thus, a 2-year migrant
is a fish that migrates to sea in its second year of life, a 3-year migrant in its
third year.

' Refers to the number of winters spent in the ocean before the fish leturns
to fresh water to spawn.

1 This method of designating the age of Pacific salmon was first introduced
by (iilbert and Rich (1927). The first number denotes the total age of the
fish (figured from time of egg deposition), and the subscript represents the
year of life that it migrated from fresh water to the sea. Thus, a 4: salmon.
called "four-two," refers to a fish that migrated to sea in its second year and
returned as an adult in its fourth year of life.

462

ized by a consistent contribution of the 53 age
group or "2-year-in-the-lake" fish (Henry, 1961).
Koo and Smith (1960) noted that various localities
in the Iliamna-Clark system of the Kvichak River
drainage in Bristol Bay (fig. 1) showed different
age compositions. They stated that this was clear
evidence of the segregation of subpopulations.
Segregation of spawning groups in time and by
age might also occur in the commercially important
sockeye salmon runs of other river systems of
Bristol Bay.

Knowledge of segregation is basic to under-
standing the dynamics of sockeye salmon stocks.
Further, it would provide information essential in
designing studies to identify and determine the
abundance of populations in the fishery or in the
trunk stream before they disperse to the spawning
grounds. Finally, such knowledge would have
application in showing whether, and to what
extent, individual spawning populations could be
managed independently in the fishery and what
effect present and contemplated regulatory policies
could have on these populations.

The purposes of this study were: (1) To deter-
mine the extent that major spawning populations
of Naknek sockeye salmon may be segregated by
time of occurrence in the run, (2) to determine by
age study the seasonal pattern of age distribution,
and (3) to determine age segregation on the spawn-
ing grounds.

The Naknek River system is one of the major
producers of sockeye salmon in Bristol Bay (fig.
1). In some years the sockeye salmon run to the
Naknek system has exceeded that to the Kvichak
River system, which is generally the most pro-

Figure 1. — Bristol Bay, showing locutions of principal
river systems and the Naknek-Kvichak fishing district.

U.S. FISH AND WILDLIFE SERVICE

ductive, and has made up most of the Naknek-
Kvichak commercial catch. The true size of the
Naknek run in any one year is difficult to assess
because that portion of the run taken in the com-
mercial fishery intermingles in the Naknek-
Kvichak fishing district (fig. 1) with sockeye
salmon bound for several of the other rivers
entering Bristol Bay. In most years the total
catch of sockeye salmon in this district has
equaled or exceeded the total spawning escape-
ment to these rivers. Spawning escapements in
excess of 2 million have been estimated for the
Naknek in recent years, giving some indication of
the productivity of this system.

Commercial fishing for sockeye salmon in
Bristol Bay is done almost entirely by a gill net
fishery which is intense and efficient and capable
of taking most of the fish in a district during an
open fishing period, essentially eliminating spawn-
ing escapement. In the present management of
the Naknek stocks the entire run is treated as a
homogeneous mixture; therefore, to allow spawn-
ing escapement from all parts of the run, the
fishery is regulated by periodically opening and
closing the Naknek-Kvichak district to fishing.

The spawning grounds of the Naknek River
system include a complex of four lakes, Naknek,
Brooks, Grosvenor, and Coville, and intercon-
necting and tributary streams (fig. 2). The
annual sockeye salmon migration to the Naknek
includes fish destined for interconnecting streams,
the tributary stream, and beach spawning areas
of all four lakes. Before this study, it was not
known if spawning groups could be identified by
time of migration.

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Figure 2. — Naknek River system, showing the location
of tagging site, weirs, and observation towers.

The Naknek run is of relatively short duration,
normally occurring between mid-June and late
July, however, spawning takes place over a con-
siderably longer period of time. Depending on
the area utilized, spawning may begin as early as
late July or as late as early October. The peaks
of spawning activity occur about mid-August on
the lake tributary streams and during the latter
part of September on the interconnecting streams
and lake beaches.

Segregation of populations by age groups by
time of occurrence in the run and on the spawning
grounds has been reported to occur in other river
systems, but before this study, little was known
of the extent to which this occurred in the Naknek
River system.

MATERIALS AND METHODS

Of the various methods now used to identify
races of salmon, the tag and recovery technique
supplemented by age analysis was considered to
be the most direct means for accomplishing the
purposes of this study.

TAGGING OPERATIONS

Salmon were captured and tagged daily in 1962
by Bureau of Commercial Fisheries personnel at
a site on the south bank of the Naknek River
24 miles above the mouth (fig. 2). Most of the
upstream migration in the vicinity of the tagging
site occurs along the south bank of the river.

Sockeye salmon ascending the trunk streams
characteristically migrate in a narrow band close
to shore. Specimens for tagging were caught in a
"seine trap" (fig. 3), consisting of a 400- by 12-
foot beach seine having 3-inch mesh (stretch
measure). The seine was set by boat from shore
and attached to a steel stake driven into the river
bottom 150 feet offshore. The remaining 250
feet of seine was allowed to trail downstream with
the current, forming a partial rectangular enclosure
of about 38,000 square feet open on the down-
stream side. The free end of the net was attached
to shore by a rope. The upstream portion of the
seine attached to the stake was fitted with a trip
lever that could be released by a rope leading to
shore. When an observer located in a tower on
the river bank saw fish entering the enclosure,
the lever was tripped, releasing the net from the
stake and allowing it to be carried downstream
around the fish. Meanwhile, the free downstream

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER

463

Figure 3. — Beach seine trap used to capture sockeye salmon for tagging, Naknek River, 1962. Dock is at right.

end of the net was pulled to shore, completely
enclosing the fish.

Three men tagged the fish. The first dipped
fish from the holding pen and transferred them to
tubs containing an anesthetic; the second trans-
ferred the anesthetized fish to the tagging cradle
and held it; and the third attached the tag and
released the fish.

Two anesthetics were used. From June 24 to
30, tricaine methanesulfonate (MS 222) was used;
from July 1 to 18, the remaining period of the
experiment, quinaldine was used because of its
more rapid action in producing anesthesia.

A pair of 1-inch plastic disk tags was attached
to the fish (one on each side) with a nickel pin
that was inserted through the fleshy part of the
back about 1 inch below the base of the posterior
to the insertion of the dorsal fin. A different
color combination of tags was used each day
(table 1), making it possible to determine the
date of tagging through visual observation of

tagged fish on the spawning grounds. The tags
applied to the left side of the fish were serially
numbered.

Between June 24 and July 18, 1962, 6,822
sockeye salmon were tagged (table 1), accounting
for 0.94 percent of the estimated total run and
giving an estimated tagged to untagged ratio of
1:106.

TAG RECOVERY

Tagged fish recoveries were in the form of both
visual observations and actual recaptures. Ob-
servations provided information only on the date
of tagging. Recaptures yielded additional infor-
mation on age, length, and sex.

SAMPLING FOR AGE, SIZE, AND SEX

A portion of the fish captured and tagged each
day was sampled to determine the age, size, and
sex composition of the Naknek spawning escape-
ment. Some fish from every seine haul were
sampled, the exact number depending on the size

464

U.S. FISH AXD WILDLIFE SERVICE

Table 1. — Sockeye salmon in daily escapements and num-
ber and percent tagged, Naknek River, June $4 to July SI,
1962

Date

Fish in daily
escapement '

Tag color
combination 2

Fish tagged in daily
escapement

June 24. _

Number

7,122

1,578

1,434

10,974

74,286

20, 214

10,956

20, 112

21,666

293,712

128, 514

115,938

6,024

2, 412

1,116

1,182

1,194

2,142

954

666

792

372

216

B-G

Number

113

324

726

109

144

588

525

1,704

713

660

178

314

204

213

106

Percent

W-Y

<3)

R-B...

0.44

Q-W...

7.16

28.. ...

Y-R

0.42

B-W

2.95

R-G...

0.98

July 1—

Y-B

.54

W-R

1.31

3...

G-Y

2.92

4 ..

B-B

2.42

R-R__

0.58

Y-W...

.55

G-G .

.57

B-Y...

2.95

W-G

13.02

Y-Y

18.28

B-R

18.02

12...

G-B

8.88

R-W

1.45

14...

W-B

2.62

Y-G

1.65

18 *

R-Y

4.63

19...

20—.

21...

Total .

723,666

6,822

0.94

1 Escapement estimates provided by Alaska Department of Fish and
Game. Margin of error determined from previous studies is 3 percent of
estimated total run.

J Colors used were blue (B), green (G),red (R), white (W),and yellow (Y).
The first letter of a color combination designates the left side tag color.

3 Percent of daily escapement tagged was not completed for the first 2 days.
The earliest fish to arrive commonly held up between the tagging and tower
sites below the rapids for a day or two until the schools build up in size.

* Tagging ended on this date.

of the catch and the magnitude of the daily
escapement. If the escapement and seine catch
were small, every fish was sampled; if they were
large, every second, third, or fourth fish was
sampled. A total of 3,094 fish, or about 45 per-
cent of the total number tagged, were sampled.

Samples were also taken from individual
spawning grounds during the period of spawning
activity and from the weirs on Brooks River and
American and Hardscrabble Creeks almost daily.
In addition, fish obtained during beach seining
for tag recovery records were sampled for age, size,
and sex. Survey crews covering the smaller
tributary streams for tags sampled the spawners
in these areas.

Tagged fish were seen near the outlets of all
lakes and on some spawning grounds. Observers
in towers located on each bank of the river at the
outlet of Grosvenor and Coville Lakes (fig. 2)
recorded the number of fish and the color combina-
tion of all tags seen entering these lakes. At
Brooks Lake observers recorded tagged fish as they
passed through counting gates of the Brooks River

weir (fig. 2). On certain spawning grounds it was
necessary to rely largely on observations of tagged
fish, because sometimes the fish could not be
recaptured. This was particularly true for salmon
spawning on Grosvenor Lake beaches and deep
swift portions of Grosvenor River and Naknek
Lake outlet areas. Here observers counted tagged
fish from towers located on boats.

Actual recaptures of tagged fish were obtained
from several sources. On Brooks River and
American and Hardscrabble Creeks (fig. 2) , tagged
fish were obtained at weir traps. Tributary and
interconnecting streams that were not checked
by means of weirs were surveyed for tagged fish
on foot or by boat several times during the spawn-
ing period. In some of the larger and deeper
streams, tagged fish were recaptured by beach
seining or by spearing with the use of skin diving
and scuba diving techniques.

Total spawning ground recoveries amounted to
1,202 fish, or about 18 percent of those tagged
(table 2). An additional 82 tagged fish were
sighted, but the color combinations could not be
positively identified.

Scales taken from sockeye salmon at the time
of spawning have margins that are absorbed to
such an extent that only fresh-water age is dis-
cernible on a projector. It was necessary to resort
to length-frequency distributions of 2- and 3-ocean
sockeye salmon derived from fish sampled at the
tagging site (1,428 males and 1,621 females) for
the assignment of ocean age to each fish sampled
on the spawning ground. Approximately 98 per-
cent of the fish in the 1962 escapement spent 2 or 3
years in the ocean. For assignment of ocean age,
the dividing line used between fish of 2-ocean and
3-ocean age was 540 mm. for females and 553 mm.
for males. Fish shorter than those lengths were
considered as 2-ocean, and those longer as 3-ocean.
I found no discrepancies between ages assigned to
tagged salmon sampled twice — in the trunk stream
and on the spawning grounds.

Fish were measured to the nearest millimeter
from the center of the eye to the fork of the tail.

The sex of each fish was determined from exter-
nal characteristics.

METHODS OF ANALYSIS
Seasonal Timing of Spawning Populations

The extent of segregation of individual spawning
populations by time of occurrence in the run may

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER
774-711 O — 66 12

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U.S. FISH A^TD WILDLIFE SERVICE

be shown by the number and distribution of color
combinations of tagged fish on the spawning
grounds. Theoretically, with no segregation the
frequency distributions of color combinations
occurring on particular spawning grounds should
be similar to those of the overall tagged popula-
tion.

Because of the size and depth of many spawning-
areas we could not recapture or see all tagged fish
present. If the likelihood of recapture or observa-
tion were equal for all tag color combinations,
spawning ground recoveries should have reflected
the relative proportion of tags from each day of
tagging. Minor disagreement between actual and
expected tag recovery proportions could have
occurred as a result of sampling variation and
would not necessarily indicate segregation. On
the other hand, any substantial disagreement
could be taken as a sign of segregation.

Actual tag recoveries were compared with the
expected recoveries for major spawning grounds
of the Naknek system in two ways: (1) By
graphical comparison of the pattern of weighted
spawning ground recoveries by day of tagging with
the pattern of the daily escapement passing the
tagging site, and (2) by statistical comparison
using contingency x2 analysis (Snedecor, 1956)
to test the hypothesis of like tag recovery distribu-
tions between spawning areas.

It would have been desirable to tag a given
proportion of the run each day so that individual
spawning populations would have been tagged in
proportion to their daily abundance. This would
have made it possible to compare directly the
spawning ground recoveries for each day of tagging
with the appropriate daily escapement size. This
could not be done, however, because the size of
the daily escapement, which was counted upstream
from the tagging site, was unknown before each
day's tagging.6 Salmon in the escapement were
counted daily from observation towers located
on each bank of the river 1% miles upstream from
the tagging site (fig. 2). Counting migrating
sockeye salmon from towers has been proved a
reliable method of assessing the size of daily
escapements in Bristol Bay7 (Becker, 1962).

The number <>f recoveries was dependent on the
number of fish tagged (/-0.949,d.f. = 21, P (0.001)),
but because a different proportion of the run was
tagged each day, recoveries were weighted to make
them directly comparable to the daily escapement
size. Weighting was accomplished by adjusting
the number of fish tagged each day to a standard
proportion of the daily escapement. The standard
selected was the proportion tagged (0.58 percent)
on July 5, the day when the greatest number of
fish were tagged (table 1). Weighted spawning
ground recoveries for each day's tagging were ob-
tained as follows:

Q.5SA

6 Estimates of the daily escapement size were provided by the Alaska
Department of Fish and Game (table 1).

' Star! of the Administration of Alaska Commercial Fisheries. 195f>.
Progress report and recommendations for 1957, 34 pp. [Processed.]

Where :

W= Weighted recoveries
A = Actual recoveries
0.58 = Proportion of the escapement tagged on
day of greatest tagging
X= Proportion of the run tagged on day in
question

For any spawning area, the proportion of adjusted
recoveries for each day of tagging is thus directly
comparable to the daily escapement. I obtained
the graphical pattern of tag recoveries for selected
spawning areas by plotting the percentage of the
total adjusted recoveries by day of tagging and
compared this pattern with that of the daily
escapement, which was obtained by plotting the
percentage of the total escapement on each day of
tagging. The amount of disagreement or simi-
larity between the two graphs indicated the extent
of segregation.

We recovered adequate tags to make this
comparison for most of the known major spawning
grounds of the Naknek system; however, for
some areas the difficulty encountered in sampling
the spawning populations resulted in insufficient
recoveries to make comparisons. These included
the beach spawning areas of Grosvenor Lake,
the tributary streams of the Savonoski River,
and a "suspected" beach spawning area in Iliuk
Arm of Naknek Lake (fig. 2). For most of the
small lateral tributary streams with small spawn-
ing escapements, tag recoveries were so few that
streams had to be grouped to provide sufficient
recoveries for comparison.

Some problems were encountered in identifying
tag color combinations. In shallow-water streams

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER

467

(less than 5 feet deep), most tag color combina-
tions were easily identified, but in deep-water
spawning areas (more than 5 feet deep), most
observers reported some difficulty in positively
identifying green tags and in distinguishing light
blue and yellow tags from white. Red tags were
identified the most easily in deep water. Thus,
the assumption of equal likelihood of observation
for all tag color combinations would not hold
true for fish in deep water. The degree of effi-
ciency of observing tagged fish in deep water
depends on the depth of the water and the tag
color combination. Fortunately, most known
spawning in the Naknek system takes place-
in water that is less than 5 feet deep.

In analyzing recoveries for the experiment, I
compared the following spawning areas and the
escapement in the manner described above.

1. Individual lakes, i.e., Naknek, Brooks,
Grosvenor, and Coville. In this comparison
the corrected upstream Brooks River weir count
of tagged fish was used as the total recoveries for
the lake. This was done because few tags were
returned from the Brooks Lake tributary streams.
The upstream tag count was corrected by de-
ducting tagged fish that moved back downstream
through the weir to spawn in Brooks River.
For the other lakes, tag recaptures and sightings
obtained by all methods (i.e., during stream
surveys, at spawning stream weirs, by beach
seining, and by skin diving) were totaled for all
streams draining into each lake.

2. Individual, large major valley or terminal
streams with similar physical characteristics and
periods of spawning activity and with recorded
escapements in excess of 10,000 fish. These
include American, Hardscrabble, Margot, and
Bay of Islands Creeks which drain into Coville,
Grosvenor, and Naknek Lakes respectively (fig.
2). Headwater Creek, major tributary of Brooks
Lake, had too few recoveries for comparison
(table 2).

3. Interconnecting streams (Brooks and Gros-
venor Rivers).

4. Grouped small lateral tributary streams of
all four lakes combined.

5. Naknek River area at the outlet of Naknek
Lake.

Recoveries for days or periods of tagging were
arranged in contingency tables for comparisons
between selected spawning areas, and the pro-

portion of tags in each period was tested for
independence by chi-square. Spawning areas
compared in this manner were essentially those
listed above. In addition, tag recoveries from
the small lateral streams of each lake were grouped
to provide adequate numbers for testing and were
treated as a single spawning unit. Tag recovery
proportions for lateral streams of each lake were
compared and tested. Comparisons and tests
were also made between spawning areas of unlike
physical characteristics, escapement records, and
spawning periods (i.e., between the large major
valley streams, small lateral streams, and inter-
connecting streams).

For most of the areas compared, tag recoveries
from single days of tagging were too few to permit
tests of independence on a day-to-day basis,
and sufficient recoveries were obtained by com-
bining the recoveries from several continuous
days of tagging into a number of periods that
included all 23 days of tagging. Tests of inde-
pendence were thus made on a period-to-period
basis.

Tests for segregation were grouped into tagging
periods based on the area of spawning. In the
lakes, the 23-day tagging experiment was divided
into seven tagging periods with 3 days in each
period, except the first and last periods, which
had 4 days. In the other spawning areas, it was
necessary to group the laggings into three periods.
These periods were unequal in length because they
were based on the daily escapement pattern ,of
the run (table 1). The first period, representing
early-run salmon, included recoveries from laggings
between June 24 and July 2. This period con-
tained an early peak of abundance, which is usually
characteristic of the Naknek sockeye salmon run.
This early peak may represent spawning groups
that are segregated in time of occurrence and
destined for particular spawning areas. The
second period representing middle-run fish, which
compose most of the escapement, extended from
July 3 to 8, inclusive. The third period, repre-
senting "tail-of-the-run" fish, included recoveries
from July 9 to 18 taggings.

Age Segregation by Time of Occurrence on the Run
and on the Spawning Grounds

Segregation of population by age groups by time of
occurrence in the run was studied as follows. The
percentages of the various age groups in the daily

468

U.S. FISH AND WILDLIFE SERVICE

escapement were determined from scale readings.
Percentages for the four dominant age groups
(42, 52, 53, and 63), which made up 98 percent of the
1962 escapement, were plotted graphically for
each day of sampling. This was done for males
and females, both separated and combined. The
graphs were examined to determine if particular
age groups tended to be segregated in certain
portions of the run. Similar graphs were prepared
for the percentage of salmon that had spent 2 and
3 years in fresh water and 2 and 3 years in the ocean.
The 1962 escapement was composed almost en-
tirely (99.8 percent) of fish of 2- and 3-fresh-
water age, and 98 percent of 2- and 3-ocean age.
These graphs were examined for the extent of
segregation by both fresh-water and ocean ages.

Age segregation on the spawning grounds was
studied by comparing the age composition of
individual spawning ground samples with each
other and with age composition of the total es-
capement. The age composition of the total
escapement was derived from the daily percentage
age composition, weighted according to the size
of the daily escapement. The escapement and
spawning ground age compositions were compared
on the basis of age group and of fresh-water and
ocean ages. Theoretically, with representative
sampling of all spawning areas, a lack of segrega-
tion by age categories would be shown by close
agreement between the total escapement and the
individual spawning ground age compositions.
Substantial disagreement would indicate segrega-
tion.

The frequencies of occurrence of the four age
groups (i.e., 42, 52, 53, 63) in most of the run were
arranged in a contingency table to compare the
age compositions of the individual major spawning
grounds of the Naknek system. The proportion
of fish in each age group was then tested for in-
dependence by chi-square. A probability value
of less than P=0.01 was considered to indicate
unlike age compositions between the areas tested
and, therefore, segregation by age on the spawning
grounds.

RESULTS AND DISCUSSION

Extent of Segregation by Time of Occurrence in the
Run

Graphical comparisons of the pattern of weighted
recoveries by day of tagging with the pattern of
the daily escapement are a somewhat subjective

approach to studying the extent of segregation.
On the other hand, statistical tests of like tag
recovery distributions between spawning areas are
objective in nature. Results obtained by both
methods were similar.

Results of Graphical Comparisons

Graphical comparisons of the pattern of weighted
tag recoveries for individual spawning areas by
days of tagging with the pattern of daily escape-
ment to the entire system are presented in figures
4-7.

It is obvious from these comparisons that most
of the spawning areas derive their escapement
from all portions of the run. In most areas the
proportion of tag recoveries appears, in general,
to be related to the size of the escapement on the
date of tagging. Greater variability between the
tag recovery and escapement pattern is apparent
for such areas as Bay of Islands and Margot
Creeks, Grosvenor River, and Naknek River at

o
o

cr <

uj h-

> o

o i-

U u-

ui o

z
<

a
<

25 30

JUNE

BAY OF ISLANDS
CREEK, NAKNEK
LAKE-RECOVERIES
n=40

MARGOT CREEK
NAKNEK LAKE-
RECOVERIES
n=6l

NAKNEK RIVER
ESCAPEMENT

Figure 4. — Naknek River escapement and weighted
spawning ground tag recovery distributions by day of
tagging, 1962 (Margot and Bay of Islands Creeks).

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER

469

LATERAL STREAM
RECOVERIES
ALL LAKES COMBINED
12

AMERICAN CREEK
COVILLE LAKE-
RECOVERIES
n=360

HAROSCRABBLE
CREEK GROSVENOR
LAKE-RECOVERIES
n=l22

NAKNEK RIVER
ESCAPEMENT

Figure 5. — Naknek River escapement and weighted
spawning ground tag recovery distributions by day of
tagging, 1962 (lateral streams, American Creek, and
Hardscrabble Creek) .

40-
30-
20-
10-
0 —

O -

« 10
o

u- 0
o

z 40

0=30
-l

^-•v ^^

GROSVENOR RIVER

-RECOVERIES

n=32

BROOKS RIVER
NAKNEK LAKE
RECOVERIES
n=249

NAKNEK RIVER
OUTLET OF
NAKNEK LAKE-
RECOVERIES

NAKNEK RIVER
ESCAPEMENT

Figure 6. — Naknek River escapement and weighted
spawning ground tag recovery distributions by day of
tagging, 1962 (Naknek River, Brooks River, and
Grosvenor River).

the outlet of Naknek Lake (figs. 4 and 6), which
had a small number of recoveries (table 2).
Spawning areas such as American Creek and
Brooks River (figs. 5 and 6), which had a sub-
stantial number of recoveries, tend to conform
more closely to the daily escapement pattern.

The tag recovery pattern for American Creek
(fig. 5) is taken to be representative of the entire
escapement into Coville Lake. American Creek,
one of the most important spawning areas in the
Naknek system, usually receives practically the
entire spawning escapement entering Coville Lake.
The escapement to the few small lateral streams
of Coville Lake in 1962 was only a fraction of that
which spawned in American Creek. Only four
tags were recovered from these streams (table 2),
and they do not change the pattern illustrated by
the American Creek recoveries.

The small lateral streams of all lakes had too
few tag recoveries for comparison with the escape-
ment on an individual basis; however, the few tags
obtained from individual lateral streams were from
tags applied throughout the run. When these re-
coveries are grouped by lakes and weighted in the
manner previously described, they provide a pat-
tern quite similar to that of the escapement (fig.
5). The indication is that the escapement to the
small lateral streams is also derived from all parts
of the run and generally in proportion to the size
of the daily escapement.

Two areas, however, seem to show some degree
of segregation of their spawning populations. The
pattern of recoveries for Brooks Lake shows a
greater proportion of tags from the early portion
of the run (i.e., before July 2) than the pattern
for the other lakes (fig. 7). This is evident not

470

U.S. FISH AND WILDLIFE SERVICE

JUNE

Figure 7. — Naknek River escapement and weighted
spawning ground tag recovery distributions by day of
tagging, 1962 (Grosvenor Lake, Brooks Lake, and
Naknek Lake).

only in the Brooks River weir tagged fish count
but also in the tag recoveries from the streams
tributary to Brooks Lake (table 2).

Grosvenor River had no tagged fish from the
early part of the run (fig. 6). Grosvenor River is
one of the areas where considerable difficulty was
experienced in recapturing tagged fish and in
identifying the color combination of those sighted.
It is possible, because of the generally smaller
numbers of fish tagged in the early part of the run
and the few tagged fish recaptured or identified
(table 2), that sampling was inadequate and early-
run fish were missed as a result of chance. On the
other hand, fish from late-run taggings (i.e., after
July 2) comparable in size to fish in some early-run
taggings were recaptured or sighted in Grosvenor
River. This plus the fact that tags were not
recovered from the only large tagging day, June

30, in the early part of the run (table 1) strongly
suggests segregation of the Grosvenor River
population in the latter part of the run. Not
enough tags were recovered, however, to formulate
a definite conclusion concerning the segregation
of the Grosvenor River spawning populations.

Results of Statistical Comparisons

Chi-square tests of the hypothesis of like re-
covery distributions for comparisons between
similar and dissimilar spawning areas yielded
results that substantiate those presented above.
Probability values less than P=0.05 are con-
sidered to indicate unlike tag recovery distributions
and, therefore, segregation in time of occurrence in
the run.

For the comparison between major valley or
terminal streams (American, Hardscrabble, Bay
of Islands, and Margot Creeks (table 3)), a value
of x2=5.38, d.f. = 6, P=0.50 was obtained. This
high value of P indicates no significant difference
between the tag recovery distributions for these
streams and, therefore, little segregation of their
spawning populations by time of occurrence in the
run.

A value of x2=4.49, d.f. = 4, P=0.37 was
obtained from the comparison of recovery dis-
tributions for the grouped lateral streams of
Naknek, Brooks, and Grosvenor Lakes (table 4).
Coville Lake lateral streams could not be included

Table 3. — Numbers of tags recovered by dates of tagging for
major valley streams, Naknek River system, 1962

Tags recovered by dates ot tagging

Total

June 24-July 2

July 3-8

July 9-18

4
8
24

28
43
83

261

8
10
17

124

American Creek (Coville

360

Total .

415

585

Table 4. — Numbers of tags recovered by dales of tagging for
grouped lateral streams, Naknek River system, 1962

Tags recovered by dates of tagging

Total

June 24-July 2

July 3-8

July 9-18

7
6
9

31
23
14

9
6
3

Total

108

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER

471

in the comparison because of insufficient tag
recoveries. This high value of P indicates a lack of
segregation of lateral stream spawning populations
by time of occurrence in the run.

The comparison between the total recovery dis-
tributions of Naknek, Brooks, Grosvenor, and
Coville Lakes (table 5) yielded a P of less than
0.005, suggesting a difference in time occurrence in
the run for the populations destined for these
lakes. However, almost two-thirds of the chi-
square value of 56.57, d.f. = 18 is due to the occur-
rence of a greater than expected proportion of
early-run tagged fish in the Brooks Lake escape-
ment (fig. 7). ff the Brooks Lake tag recoveries
are excluded from consideration and a comparison
made only between Naknek, Grosvenor, and
Coville Lakes recovery distributions, the resulting
X2=7.43, d.f. = 12, P=0.82. Thus, the recovery
distributions for these three lakes are not sig-
nificantly different, and segregation of their
spawning populations as a whole is minimal. For
Brooks Lake, however, results suggest that it
derived a relatively greater proportion of its
spawning population from the early part of the
run than did the other three lakes.

Table 5. — Numbers of tags recovered by dates of tagging for
Naknek, Brooks, Grosvenor, and Coville Lakes, 1962

Lake

Tags recovered by dates of tagging

Total

June
24-27

June
28-30

July
1-3

July

4-6

July
7-9

July
10-12

July
13-18

11
9

S
5

36
34
12
25

61
18
26
47

233

67
110
202

50
17
25
47

13
3
3
7

Coville

Total

107

152

612

139

123

1,189

Comparison of the tag recovery distributions of
unlike spawning grounds, which include the
grouped lateral streams of all lakes, Brooks and
Grosvenor Rivers (representing interconnecting
streams), and American and Hardscrabble Creeks
(representing major valley streams) (table 6),
yielded a value of x2= 14.87, d.f. = 8, P=0.06.
This value is essentially at the level of probability
(P=0.05) below which values of P are considered
to indicate unlike tag recovery distributions. The
cause of the large x2 and resulting low probability
level is associated with the absence of early-run
(June 24 to July 2) tagged fish in the Grosvenor
River recoveries (fig. 6). More than one-third of

the x2 value of 14.87 is caused by the lack of these
early-run tagged fish. Although, statistically, the
test does not indicate a tag recovery distribution
for Grosvenor River unlike that of the other
spawning grounds, the lack of early-run tagged
fish in the recoveries and the resulting large chi-
square suggest that this area may have derived its
escapement primarily from the latter part of the
run. If Grosvenor River recoveries are excluded
from consideration and a comparison made only
between the grouped lateral streams, American
Creek, Brooks River, and Hardscrabble Creek, the
resulting x2=8.70, d.f. = 6, P=0.20.

Table 6. — Numbers of lags recovered by dales of lagging for
unlike spawning grounds, Naknek River system, 1962

Spawning ground

Tags recovered by dates of tagging

Total

June 24-July 2

July 3-8

July 9-18

Grouped lateral streams:

41
0

261
83

164
25

108

Major valley streams:

360

Hardscrabble Creek

Interconnecting streams:

124
250

Total

130

601

143

874

Discussion

There is some evidence of heterogeneity between
the individual spawning ground tag recovery dis-
tributions as compared above. Only Brooks Lake
had a tag recovery distribution that differed signifi-
cantly from those of the other spawning grounds.
The distributions for both the lateral streams and
the escapement as a whole show that a higher
proportion of early-run fish entered Brooks Lake
than the other three lakes. Grosvenor River re-
coveries indicate that it may have received its
escapement primarily from the middle and later
parts of the run (i.e., after July 2).

Apart from the above situations, however, the
evidence presented fails to indicate any clear
segregation of most of the known spawning popu-
lations composing the Naknek run. It is clear that
the recovery distributions for most spawning
areas are not significantly different from one
another or from the seasonal escapement pattern
in the trunk stream. Most areas apparently
derive their spawning populations from all parts
of the run and, generally, in proportion to the
daily escapement.

472

U.S. FISH AND WILDLIFE SERVICE

As mentioned earlier, the Naknek River sockeye
salmon run is of relatively short duration when
compared with rivers like the Fraser and Karluk.
The total spawning escapement enters the Naknek
system during a 4- to 6-week period, and normally
over half the total escapement occurs in a period
of 3 to 5 days (table 1). Spawning activity, how-
ever, occurs over a period of 2% months, although
the period and duration of spawning are quite
different for the various grounds used. Time of
spawning apparently has little effect in producing
segregation. Regardless of the characteristics of
spawning activity, most grounds seem to receive
their escapement proportionately from all parts
of the run.

It seems apparent that the short duration of
the Naknek run is not an adaptation to a single
optimum spawning period for the Naknek system
as a whole, and it is probable that the conditions
responsible for the compressed nature of the run
occur in the ocean before Naknek salmon reach
Bristol Bay. Regardless of the cause, it is likely
that the short duration of the run is responsible
for the significant lack of segregation. The
result is, of necessity, a more or less complete
intermingling of the spawning populations com-
posing the Naknek sockeye salmon run in the
trunk stream and, therefore, in the fishery. In
view of this, it seems impossible now to manage
in the fishery the individual spawning groups
composing the run.

AGE SEGREGATION BY TIME OF OCCURRENCE
IN THE RUN

The daily percentages of the four dominant age
groups (42, 52, 53, and 63) in the 1962 escapement
were determined from samples of fish taken at
the tagging site. Little difference was noted
between the daily age composition of males and
females. Both sexes showed similar daily fluctu-
ations in abundance. The age data for males and
females were, therefore, combined (fig. 8).

Although daily fluctuations in age composition
of the escapement did occur, there were no marked
changes in age composition during the run. Only
the 53 age group appeared to increase in relative
abundance toward the end of the run. During
the peak escapement period of July 5-7 (table 1),
the proportion of the 52 age group was somewhat
higher and the 53 group lower than the overall
seasonal average for these groups. Except for
daily fluctuations, there appears to be little change

!••-

60-

50-

40-

30-
20-

10-

f*\ > — > y^-y^<i^\ /

1 1 * — 1

5 10 15

JUNE

JULY

70-

60-

50-

40-

30-

20-
10-

1 \
i

1 1 i

30
NE

5 10 15
JULY

Figure 8. — Percent contribution of four dominant age
groups of sockeye salmon by day of tagging in Naknek
River escapement, 1962.

in the age composition of the escapement with the
passage of time. Segregation on the basis of age
groups appears to have been minimal in the 1962
Naknek escapement.

In figure 9 the daily age composition of the
escapement is replotted by fresh-water and ocean
age. When examined from this standpoint, only
minor changes in age composition appear to occur
during the run. The proportion of 3-fresh-water
fish increases, while the 2-fresh-water group
decreases slightly after the peak escapement
period of July 5-7. Also, the proportion of 3-
ocean fish is somewhat higher and that of 2-
ocean fish lower during the peak escapement period.
There is, however, no marked change in the pro-
portion of any age category during the run.
Segregation in time by ocean and fresh-water age
appears to have been limited in the 1962
escapement.

To what extent the daily age composition of the
Naknek escapement is altered by effects of the
fishery is unknown. It is known, however, that
the Bristol Bay gill net fishery tends to be selective
for the larger or 3-ocean fish (i.e., the 52 and 63
age groups). It is possible that the fishery could
account for the marked day-to-day fluctuations

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER

473

I- ^

o —

I- 0.

^ 3

w o

5 cr

lij o

HJ 2

g°

80-
70-
60-
50-
40
30
2 0-

10-
0-

80
70-
60-
50-
40
30
20-
10
0-

2 FRESH-WATER

3 FRESH-WATER

25 30

JUNE

"I 1

5 10

JULY

I * A ,\

\ I \ , \ M

V i / i ' * / \ ' '

—^' I I * SJ " \

\l v y i

2 OCEAN —

30CEAN

— I 1 —

25 30

JUNE

— r-

NAKNEK LAKE OUTLET
n=80

Figure 9. — 'Percent daily age composition of sockeye
salmon by fresh-water and ocean age, Naknek River
escapement, 1962.

that sometimes occur in the age composition and
perhaps produce or mask seasonal trends in age.

AGE SEGREGATION ON THE SPAWNING GROUNDS
Results

Tn figures 10 and 11 and table 7 the age compo-
sitions of fish sampled on the spawning grounds are
compared with the age compositions of fish sampled
at the Naknek River tagging site. In the figures
oidy the individual spawning grounds of each
lake with a sample size greater than 25 are com-
pared with the Naknek River samples. Com-
parisons are made on the basis of dominant age
groups (i.e., 42, 52, 53, and 63) and fresh-water and
ocean age. A complete summary of all age cate-
gories present in the samples obtained from all
spawning grounds covered in this study is given
in table 7.

Figures 10 and 11 and table 7 reveal marked
variation in the age composition of the spawning
ground samples when compared with each other

jnn

JLTUL

fTTTTI

Cvv3 Ei£li

ESS

NAKNEK RIVER SAMPLES
WEIGHTED

2 3

AGE GROUP

'FRESH-WATER' OCEAN AGE
AGE

Figure 10. — Percent composition of sockeye salmon
escapement for major spawning tributaries of Naknek
Lake by age group and fresh-water and ocean age, 1962.

and with Naknek River samples. This strongly
suggests the segregation of populations by age on
the spawning grounds of the Naknek River
system.

For the major spawning grounds of the Naknek
system, the frequencies of occurrence of the four
dominant age groups are arranged in a 4-by-9
contingency table (table 8). A chi-square test
of the hypothesis of like age compositions for the
spawning grounds being compared yielded a
value of x2=549.21, d.f. = 24, P=0.005. Since
the value of P is well below the adopted 0.01
level of significance, it constitutes convincing
evidence of unlike age compositions between the
areas compared and, therefore, segregation by

474

U.S. FISH AND WILDLfFE SERVICK

Table 7. — Age composition of so

ckeye salmon

on spawning

grounds by number and percent, Naknek

River system,

1962

Age group

Fresh-water age

Ocean age

Location

Total

Naknek Lake:
Stream N 16.1:

Number

4
36.4

2
33.3

9.1

3
27.3

3
50.0

3
60.0

5
55.6

29
96.7

1
50.0

77.4

20
90.9

21
80.8

6
75.0

5
55.6

6
13.3

36
66.7

5
83.3

30
73.2

3
27.3

4
36.4

2
33.3

7
63.6

50.0

4
80.0

5
55.6

30
100.0

2
100.0

47
88.7

24
92.3

7
87.5

8
88.9

35
77.8

51
94.4

5
83.3

36
87.8

10.7

20.0

9.1

20.0

7
63.6

6
100.0

80.0

100.0

29
96.7

1
50.0

44
83.2

20
90.9

23
88.5

6
75.0

5
55.6

7
15.6

37
68.5

6
100.0

34
82.9

3
27.3

Percent

1
16.7

20.0

Stream N 18.7:

Number...

Percent

Stream N 19.6:

Number

1
20.0

Percent ...

Stream N 23.4:

Number ..

4
44.4

Percent

Stream N 49.6:

1
3.3

Percent

Stream N 56.4:

Number

1
50.0

1.9

5.7

50.0

1.7

Percent... _ _ ...

Bay of Islands Creek:
Number

5.7

5
9.4

2
9.1

1
3.8

12.5

3
33.3

29
64.4

15
27.8

6
11.3

8
15.1

2
9.1

1
3.8

2
25.0

4
44.4

38
84.4

17
31.5

Stream N 93.7:

Stream N 110.4:

Number

7.7

1
12.5

16.7

9
20.0

2
3.7

26
8

2
7.7

1
12.5

1
11.1

10
22.2

3
5.6

1
16.7

9.8

7.7

Stream N 111.4:

Number

Percent

Stream N 133.3:

Iliuk Arm Beach:

Number

1
2.3

1.9

1
16.7

7.3

Percent ...

Margot Creek:

Number

Percent...

Stream N 142.7:

Percent _ .

Brooks River:

2.4

5
12.2

? 4

2.4

2.5

6
14.6

Location

Age

group

Fresh-water age

Ocean

age

5 3

Total

Naknek Lake:
StreamN 156.9:

1
33.3

4.2

54
67.5

137
9.5

4
11.1

6
7.1

17
11.6

8
8.5

35
5.2

66.7

23
95.8

20
25.0

975

67.8

19
52.8

8
9.4

55
37.7

30
31.9

149
22.0

1
33.3

1
4.2

60
75.0

331
23.0

9
25.0

27
31.2

36
24.7

10
17.0

230
33.9

2
66.7

23
95.8

20
25.0

1,103
76.7

27
75.0

58
68.2

108
74.0

75
79.8

446

65.8

3
100.0

24
100.0

74
92.5

1.116

77.6

23
63.9

14
17.6

73
50.0

39
41.5

185
27.3

Stream N 170.3:

Lake outlet:

1
1.3

4
0.3

19
1.3

1
0.15

5
6.2

183

12.7

5
13.9

20
23.5

19
13.0

8
8.5

193
28.5

2
0.14

1
1.3

23
1.6

5
6.2

290
20.2

13
36.1

70
82.4

73
50.0

55
58.5

489
72.1

Brooks Lake:
Weir samples:

0.1

7
0.5

1
1.2

1
0.15

107
7.5

8
22.2

50
58.8

53
36.3

45
47.9

295
43.5

2
0.1

1.438

0.6

Grosvenor Lake:
Lateral streams:

Lake beaches:

Hardscrabble Creek:

1
0.7

1
1.06

1
0.15

1
0.7

2
2.1

1
0.15

146
94

677

2
1.3

3.2

2
0.30

Percent

Grosvenor River:

Percent

Coville Lake:

American River:

Percent

0.3

Naknek River samples

0.1

11.9

0.6

28.7

35.7

1.3

21.4

0.2

0.3

41.9

57.8

0.2

0.7

47.6

50.2

1.5

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER

475

w
o

Q-

CO 80

§40-
UJ

li. o

z80

t-40-
co

£°

§80-

40-

AMERICAN CREEK
n=678

GR0SVEN0R LAKE BEACHES
n=85

Pv3 tV:

HARDSCRABBLE CREEK
n=l46

GR0SVEN0R RIVER
n = 94

rrrm

NAKNEK RIVER SAMPLES
WEIGHTED

AGE GROUP

2 3

Ifresh-water

AGE

2 3

OCEAN AGE

Figure 11. — Percent composition of sockeye salmon
escapement for American Creek (Coville Lake) and three
major spawning areas of Grosvenor Lake compared with
overall Naknek system escapement, by age group and
fresh-water and ocean age, 1962.

age on the major spawning grounds of the Naknek
River system.

Most spawning ground samples contained a
considerably higher proportion of the 53 age
group and a lower proportion of the 52 group
than did the trunk river samples. Only the Iliuk
Arm, Grosvenor Lake beach, and American Creek
samples contained a proportion of the 52 group
approaching that of the river samples. It is
notable that the samples from these three areas
also contained almost twice the proportion of the
63 age group as did the river samples. Ocean-age
samples from these three areas were characterized
by predominantly 3-ocean fish in 1962. Prac-
tically all other spawning ground samples con-
tained predominantly 2-ocean fish, many of them
with twice the proportion that occurred in the
river samples.

Fresh-water age samples from most areas con-
tained a considerably smaller proportion of 2-

Table 8. — Numbers of fish in dominant age groups in
sockeye salmon samples taken from the major spawning
grounds of the Naknek River system, 1962

Spawning area

Fish in age group—

Total

3
1
1
3

54
6

17
8

193

149

295

144

672

Total

128

260

375

497

1,260

fresh-water fish than did the Naknek River
samples. Only the samples from stream N23.4
(9 fish) and the sample taken at the outlet of
Naknek Lake (80 fish) (table 7) had greater pro-
portions of 2-fresh-water fish. For the Naknek
Lake spawning grounds as a whole there was a
lack of 2-fresh-water fish, primarily because of
the absence of the 52 age group.

Discussion

The absence of the 52 age group suggests in-
adequate sampling of the total Naknek escape-
ment on the spawning grounds. All known
spawning grounds were surveyed and sampled in
1962, but only about half of the total escapement
counted on the Naknek River could be accounted
for on the spawning grounds surveyed. It seems
likely that some major spawning areas were not
sampled and that these areas could have contained
a high proportion of the 52 age group that was so
prevalent in the river samples.

Until 1962 the Iliuk Arm beach area of Naknek
Lake was not regarded as a probable spawning
ground. During the 1962 stream surveys in this
area, however, survey crews noted large numbers
of fish jumping along a 1}2- to 2-mile stretch of
the southeast shoreline. These fish were present
after most of the tributary stream spawning had
been completed, but because of the turbid water,
we could not definitely establish whether these
fish actually spawned in this area nor could we
estimate their number. Evidence suggests, how-
ever, that they spawned in the beach area.
Subsequent sampling of these fish showed that
they were composed of a greater proportion of the
52 age group than most of the other spawning
grounds sampled. It is likely that this population

476

U.S. FISH AND WILDLIFE SERVICK

was sufficiently large to account for a substantial
portion of the 52 age group represented in the
Naknek River samples, but lacking in the samples
from the other spawning grounds.

Other probable spawning areas in the Naknek
system include the turbid Savonoski River (fig.
2) and most of its clear-water tributary streams
and deepwater beach spawning areas as yet un-
known. None of these were sampled in 1962.

Regardless of the spawning areas left un-
sampled, it seems clear from the evidence pre-
sented that there is segregation by age on the
spawning grounds of the Naknek River system.
This agrees with the conclusion reached by Koo
and Smith (1960) for various spawning areas of
the Kvichak River system in Bristol Bay.

Theoretically this segregation could be of great
importance in managing individual spawning
populations as they pass through the fishery.
If certain spawning grounds are characterized by
populations composed predominantly of fish of
2-ocean age and others of 3-ocean age, the effects
of the gill net fishery, which is selective for large
fish, would be unequal for each group. A knowl-
edge of any consistencies in the age structure of
individual spawning populations would, therefore,
provide those charged with managing the Naknek
sockeye salmon stocks with a means of gaging the
possible effects of the fishery on these populations.
Many years of data, however, will be required
before consistencies in the age structure of indi-
vidual spawning populations could show up.

The results presented above suggest two im-
portant lines of future investigation: (1) A com-
plete survey of all beach and turbid water areas of
the Naknek system for spawning areas that were
previously undetected, and (2) continued study
of segregation by age on the spawning grounds to
uncover any consistencies in the age group struc-
ture of individual spawning populations.

SUMMARY

1. Tag and recovery techniques were used to
determine the extent of segregation by time of
occurrence for the individual spawning populations
in the sockeye salmon run of Naknek River,
Alaska. Salmon were tagged daily on the Naknek
River at a site located about 24 miles above the

mouth of the river. A different tag color combina-
tion was used to identify each day of tagging.
Subsequent recovery or observations of tagged
fish on the spawning grounds and the relative
abundance of each color combination present
provided the basis for determining the extent of
segregation.

2. Results lead to the following conclusions:
(a) Segregation of individual Naknek spawning
populations by the time of occurrence in the trunk
stream was minimal. As a consequence, most
spawning grounds derived their fish from all parts
of the run and, generally, in proportion to the
size of the daily escapement. Exceptions were
Brooks River, which received a disproportionate
share of early-run spawners, and Grosvenor
River, which seemed lacking in early-run fish.
(6) The short duration of the Naknek run is
probably the most reasonable explanation for the
intermingling of most spawning groups, (c) Be-
cause of the lack of segregation in time, it is un-
likely that spawning populations can be managed
on an individual basis in the fishery. The Naknek
sockeye salmon stocks will probably be most
effectively managed, as a whole, by securing
spawning escapement proportional to the daily
abundance of fish in the fishery.

3. No seasonal trends in age composition could
be described as characteristic of the Naknek run,
probably because of intermingling of most of the
spawning populations during the run.

4. Fish from all known spawning grounds of the
Naknek system were sampled to determine the
age composition of populations associated with
the separate spawning areas. Spawning popula-
tions have age characteristics that differ signifi-
cantly from one to another and, therefore, show
segregation by age on the spawning grounds of the
Naknek River system. Continued study of
segregation by age on the spawning grounds is
necessary for a number of years to determine if the
age structure of specific spawning populations
conforms to specific patterns. It is likely that
major spawning population's as yet undetected
and, therefore, not sampled in this experiment
exist in the Naknek system. A thorough survey
to locate and determine the magnitude and age
characteristics of these populations, if any, is
needed for a complete understanding of segrega-
tion and the productive importance of individual
spawning areas within the Naknek system.

SALMON SPAWNING POPULATIONS IN NAKNEK RIVER

477

ACKNOWLEDGMENTS

Barry Muir, Assistant Professor of Zoology at
the University of Hawaii, advised and assisted in
preparing this manuscript. Charles J. DiCos-
tanzo, Chief of Red Salmon Investigations for the
Bureau in Alaska, made the age determinations
from the scales collected; and Wilbur L. Hartman,
Project Supervisor of Brooks Lake Red Salmon
-Studies, and Herbert Jaenicke and William R.
Heard, Fishery Biologists (Research), assisted in
the tag recovery program. Bristol Bay personnel
of the Alaska Department of Fish and Game
assisted in the field studies.

LITERATURE CITED

Barnaby, Joseph T.

1944. Fluctuations in abundance of red salmon,
Oncorhynchus nerka (Walbaum), of the Karluk
River, Alaska. U.S. Fish and Wildlife Service,
Fishery Bulletin 39, vol. 50, pp. 237-295.

Becker, Clarence Dale.

1962. Estimating red salmon escapements by sample
counts from observation towers. U.S. Fish and
Wildlife Service, Fishery Bulletin 192, vol. 61, pp.
355-369.

Chamberlain, F. M.

1907. Some observations on salmon and trout in
Alaska. Report of the U.S. Commissioner of Fish-
eries for 1906 and Special Papers. Bureau of
Fisheries Document No. 627, 112 pp., 5 pis.

Clutter, R. I., and L. E. Whitesel.

1956. Collection and interpretation of sockeye
salmon scales. International Pacific Salmon Fish-
eries Commission, Bulletin 9, 159 pp.

Fisheries Research Board of Canada.

1957. Annual report of the Fisheries Research
Board of Canada for 1956-57, 195 pp.

Gilbert, Charles H.

» 1914. Contributions to the life history of the sock-
eye salmon. (No. 1). In Province of British
Columbia, Report of the Commissioner of Fish-
eries for 1913, pp. 53-57.

1915. Contributions to the life history of the sock-
eye salmon. (No. 2). In Province of British
Columbia, Report of the Commissioner of Fish-
eries for 1914, pp. 15-75.

1916. Contributions to the life history of the sock-

eye salmon. (No. 3). In Province of British
Columbia, Report of the Commissioner of Fish-
eries for 1915, pp. 27-64.

1918. Contributions to the life history of the sock-
eye salmon. (No. 4). In Province of British
Columbia, Report of the Commissioner of Fish-
eries for 1917, pp. 33-80.

1919. Contributions to the life history of the sock-
eye salmon. (No. 5). In Province of British
Columbia, Report of the Commissioner of Fish-
eries for 1918, pp. 26-52.

1920. Contributions to the life history of the sock-
eye salmon. (No. 6). In Province of British
Columbia, Report of the Commissioner of Fish-
eries for 1919, pp. 35-68.

Gilbert, Charles H., and Willis H. Rich.

1927. Investigations concerning the red-salmon runs
to the Karluk River, Alaska. Bulletin of the
U.S. Bureau of Fisheries, vol. 43, part 2, pp. 1-69.

Henry, Kenneth A.

1961. Racial identification of Fraser River sockeye
salmon by means of scales and its applications to
salmon management. International Pacific Salmon
Fisheries Commission, Bulletin 12, 97 pp.

Killick, S. R.

1955. The chronological order of Fraser River
sockeye salmon during migration, spawning and
death. International Pacific Salmon Fisheries
Commission, Bulletin 7, 95 pp.

Koo, Ted S. Y., and Howard D. Smith.

1960. Main-stem and tributary sampling of red
salmon scales for population studies. U.S. Fish
and Wildlife Service, Special Scientific Report —
Fisheries No. 362, 10 pp.

Krasheninnkov, S. P.

1754. Opesanie Zemli Kamtschatka sotschennoja.
St. Petersburg. [History of Kamtschatka and the
Kurilski Islands with the countries adjacent].
Translation by James Grieve published 1764.
R. Raikes, Glocester, 280 pp.

Rounsefell, George A.

1958. Factors causing decline in sockeye salmon of
Karluk River, Alaska. U.S. Fish and Wildlife
Service, Fishery Bulletin 130, vol. 58, pp. 83-169.

Snedecor, George W.

1956. Statistical methods. 5th ed. Iowa State
College Press, Ames, Iowa, 534 pp.

Thompson, William F.

1945. Effect of the obstruction at Hell's Gate on
the sockeye salmon of the Fraser River. Inter-
national Pacific Salmon Fisheries Commission,
Bulletin 1, 175 pp.

478

U.S. FISH AND WILDLIFE SERVICE

SKIPJACK TUNA SPAWNING IN THE MARQUESAS ISLANDS AND TUAMOTU

ARCHIPELAGO

By Howard O. Yoshida, Fishery Biologist (General)
Bureau of Commercial Fisheries Biological Laboratory, Honolulu, Hawaii

Spawning of skipjack tuna (Katsmvonus pelamis) in
the Marquesas and Tuamotu areas was investigated by
examining ova from 402 pairs of ovaries collected during
exploratory fishing cruises, August 1956 to June 1958.
Investigated were size at first spawning, spawning
season, frequency of spawning, fecundity, use of the
gonad index as a measure of maturity of skipjack, and
the relation of stage of sexual development to schooling
behavior.

The length at first spawning of skipjack in the two

ABSTRACT

areas was found to be about 43 cm., although a few fish
as large as 50.7 cm. apparently were not yet ready to
spawn. Spawning activity reached a peak during
November-April. The data indicate a possibility that
individual skipjack may spawn more than once during
a season. Number of ova extruded per spawning was
estimated at 0.1 to 2 million. The gonad index could
not be used as a measure of sexual development. Skip-
jack schools tended to have fish in a similar stage of
sexual development.

From 1956 to 1959 the staff of the Bureau of
Commercial Fisheries Biological Laboratory at
Honolulu investigated the tuna resources of waters
of French Oceania around the Marquesas Islands
and the Tuamotu Archipelago. A study of the
spawning of the skipjack tuna, Katsuwonus
pelamis (Linnaeus), which appears to be the most
abundant surface-schooling species of tuna in
this aren, was included in the investigations.

This study is based on the systematic micro-
scopic examination and measurement of the ova
in skipjack ovaries, generally following the method
described by Clark (1934). Skipjack spawning
studies, based generally on the examination of
gonads or on the capture of larvae and juveniles,
have been made in many different areas of the
Pacific. On the basis of the examination of
gonads, Matsui (1942) inferred that skipjack
may spawn throughout the year in the vicinity
of Palau; Marr (194S) concluded that spawning

Xute.— Approved for publication Oct. 22, 1964.
FISHERY BULLETIN: VOLUME 65, NO. 2

occurs in the northern Marshall Islands, and
confirmed this by the capture of two juveniles;
Yabe (1954) and Yao (1955) found evidence of
spawning in the southern waters of Japan; Brock
(1954) postulated that they spawn in Hawaii from
late February, March, or April to the first part
of September; Schaefer and Orange (1956) and
Orange (1961) hypothesized that they spawn in
the vicinity of the Revilla Gigedo Islands in the
eastern Pacific; and Wade (1950a) found evidence
of their spawning in Philippine waters.

By virtue of the capture of larvae and juveniles,
Schaefer and Marr (1948) demonstrated the
existence of a spawning ground off Central
America; Wade (1950b and 1951) found further
evidence that skipjack spawn in Phdippine waters;
Shimada (1951) deduced that spawning occurs
around the Phoenix Islands; and Matsumoto
(1958) showed that they spawn in a wide area in
the central Pacific Ocean. The present study
demonstrates the existence of yet another spawn-
ing locality in the Pacific.

479

MATERIALS AND METHOD
COLLECTION OF OVARIES

This study is based on 402 pairs of ovaries col-
lected on seven exploratory fishing cruises from
August 1956 through June 1958. The approxi-
mate locales of collection are shown in figure 1.
Most of the ovaries were collected from fish caught
at the surface by pole and line. This method of
fishing, as used in the Hawaiian skipjack fishery,
was described by June (1951).

Plans for all of the pole-and-line fishing cruises
called for sampling 25 skipjack from each school
fished in order to obtain an estimate of their size
and sex composition. From the 25 fish thus
selected, the first 5 females picked at random were
cut open and their ovaries removed for examina-
tion. Skipjack were caught by pole and line
from 92 schools during this study, and ovary
samples were secured from fish from 81 of these
schools. Longline fishing and incidental trolling
provided the few remaining samples. A descrip-

-Cj>ti

• NUKIHIU

•MARQUESAS

• \ jHVA FOU

./ ISLANDS

•d

fill Itn,

I hi re 1. — Locations where skipjack ovaries used in this
study were collected.

tion of the longline fishing method was given by
Mann (1955).

The ovaries were preserved in about 10 percent
formalin. At the time of collection a record was
made of the date, locality, method of fishing, and
the fork length of the fish.

EXAMINATION OF OVARIES

Several investigators made detailed studies of
the distribution of mature ova within ovaries:
June (1953) for yellowfin (Thunnus albacares);
Yuen (1955) for bigeye (Thunnus obesus); and
Otsu and Uchida (1959) for albacore (Thunnus
alalunga). All showed that a representative
sample of ova could be obtained anywhere along
the length of an ovary or from either member of a
pair.

Similarly, an analysis of variance of the mean
size of mature ova within a skipjack ovary indi-
cated that they were homogeneously distributed.
Therefore, the following sampling method was
adopted for this study. The formalin-preserved
ovaries were weighed after excess moisture and
tissue had been removed. A cross-section about
K-inch thick was taken, usually from the middle
of the right ovary, from whicli a wedge-shaped
(triangular) sample was cut. In many instances
it was not possible to distinguish the right ovary
from the left. In these instances the smaller of
the pair was selected for examination; it appeared
that the right ovary was usually the smaller of the
two. I assumed that the distribution of ova
within the right and left ovaries is similar, as has
been reported for the tuna cited above.

The ova from the triangular section were teased
apart in a shallow dish and measured in a Sedg-
wick-Rafter counting chamber. Measurements
were made with an ocular micrometer having a
magnification of 0.016 mm. per micrometer divi-
sion. Since the ova were not perfectly spherical,
the diameter which was measured was the random
diameter that fell parallel to the lines in the
counting chamber.

At the outset of the study, 300 randomly
selected ova, 10 micrometer divisions (0.16 mm.)
or larger, were measured from each ovary in order
to characterize the size of ova at the different
developmental stages. Since this required a great
amount <>f time, and since the determinations of
the stage <>l development of the ovaries were
based on the most developed ova, the -ample size

4SH

U.S. FISH AND WILDLIFE SERVICE

was later reduced to a random sample of 2.5 of the
most developed group. Following Snedecor (1946,
p. 457), I analyzed the data on ova size distribu-
tions; my analysis showed that 25 was an adequate
number to approximate the mean size.

DEVELOPMENTAL STAGES OF OVA

Four rather distinct developmental stages were
recognized and designated as ''early developing,"
"developing," "advanced," and "ripe". The
early developing category includes ova which,
at their most primitive, appear as simple trans-
parent cells present in all ovaries. The larger
ova in this stage contained a relatively large
nucleus. The mean diameter of the early develop-
ing ova ranged from 0.16 to 0.33 mm. The ova
assigned to the developing stage were completely
opaque because of the deposition of yolk granules.
Their mean diameter was 0.37 to 0.66 mm.
The advanced stage comprised ova that were
still relatively opaque in appearance and con-
tained a cluster of small oil droplets to ova that
were semitransparent and had a well-developed,
bright yellow oil globule. The mean diameter of
these ova was 0.49 to 0.74 mm. The collection
had no ripe ovaries; however, a sample of ova from
a running ripe skipjack caught on January 26,
1957, was available for examination. This skip-
jack was caught by pole and line at 9°33' S.,
139°55' W., about 10 miles southeast of the island
of Hua Pou in the Marquesas. Its ova were used
in an unsuccessful attempt at artificial fertilization
and were preserved and brought to the laboratory.
They are almost perfectly spherical and trans-
parent, with a distinct straw-colored oil globule.
Fifty were measured. Their diameters were 0.85
to 1.12 mm., with a mean of 0.96 mm. The oil
globule was about 0.14 mm. in diameter.

The sizes of these ripe ova are similar to those
described by other investigators. Brock (1954)
found ripe ova from a skipjack in Hawaii to
average 1.125 mm. in diameter. Yabe (1954)
measured some ova from a ripe skipjack caught in
the southern waters of Japan and found that
they were 0.S0 to 1.17 nun. in diameter, averaging
1.00 mm.

DEGREE OF MATURITY

Skipjack were classified according to the stage
of development of the most developed group of
ova: the nomenclature used was the same as

for the stages of ova development. Throughout
this report, unless otherwise stated, the designa-
tions early developing, developing, advanced,
and ripe will be used interchangeably to describe
a skipjack, its ovaries, and the most developed
ova contained therein.

The early developing category included ovaries
as small as 2 g., from a sexually immature fish,
and those (from adult fish) which were relatively
large but which contained only early developing
and a few residual ova. This category also
included some ovaries containing ova thai ap-
peared to have attained the developing stage but
had begun to degenerate. These ova were
grayish, relatively soft, and easily broken.

TREATMENT OF DATA

Skipjack from the Marquesas and the Tuamotu
areas were considered together in all aspects of
this study, because I assumed that they belonged
to the same population or at least were similar
physiologically insofar as spawning was concerned.
It would have been interesting to determine
whether skipjack from the two areas did indeed
have similar spawning habits; however, the
samples from the Tuamotus were too few to
treat that area separately. Of the 402 pairs of
ovaries collected, 372 came from around the
Marquesas and 30 from the Tuamotus.

SIZE AT FIRST SPAWNING

The approximate body length at first spawning
was determined by arranging the lengths and the
stage of development of all the skipjack used in
this study into a frequency distribution (fig. 2).
The smallest skipjack measured 39 cm. This
fish had thin, ribbonlike ovaries which weighed
2 g. and contained only primitive ova. Presum-
ably it had never spawned. The ovaries of a few
fish, 43.7 to 50.7 cm. long, were classified as early
developing and also showed no positive evidence
of past spawning. A greater number in that size
range, however, had either developing or advanced
ovaries. The smallest fish that had advanced or
developing ovaries was 43 cm. long. The few fish
more than 55 cm. long that were classified as early
developing either showed evidence of past spawn-
ing or at least of having attained a stage of develop-
ment past early developing, for their ovaries con-
tained residual or degenerating ova.

SKIPJACK SPAWNING IN MARQUESAS AND TUAMOTU AREAS
774-711 O— 66 13

481

APPROXIMATE WEIGHT (POUNDS)
_6 11 18

^DEVELOPING

i \
i \

^ADVANCED

\ yWlHRH DEVELOPING

J MsZ^X^sU /r-

~-^\**c

60
LENGTH I CM.]

Figure 2.

-Skipjack length-frequency distribution and
stage of development.

It was noted earlier that one skipjack with
running ripe ovaries had been caught. Unfor-
tunately, the length of this specimen was not re-
corded. However, a sample from the school from
which this fish was taken showed their size to
range from 45.6 to 56.9 cm., and in all likelihood
this specimen fell within this length range.

It seems from these observations that, although
some skipjack as large as 50.7 cm. were ap-
parently not ready to spawn, those in the Mar-
quesas-Tuamotu areas are capable of first spawn-
ing when they are about 43 cm. long.

The size at first spawning has been determined
for skipjack in other areas of the Pacific. Brock
(1954, p. 102), discussing skipjack in Hawaii,
states, "The smallest fish that possessed maturing
ova during the spawning season were around 40 to
45 cm. long. Fish 35 to 40 cm. in length had
ovaries that, with a few exceptions, seemed im-
mature." In the southern waters of Japan, Yabe
(1954) noted that no definite information was
available because of the scarcity of data, but that
the smallest skipjack in his samples with mature
ova was 46.8 cm. long. In the eastern Pacific,
Orange (1961) found the minimum size at first
spawning for skipjack around the Revilla Gigedo
Islands to be about 55 cm., and around the Cocos
Island area about 40 cm.

From the above discussion it appears that the
size at first spawning may vary with locality.
Skipjack in the Marquesas and Tuamotus, in

482

Hawaii, and in the southern waters of Japan all
seem to mature at about the same size, while in
certain areas in the eastern Pacific they attain a
larger size before reaching maturity.

It is interesting that all samples from the
Marquesas and Tuamotus were composed pri-
marily of adult fish. The Hawaiian summer skip-
jack fishery also exploits mostly adult fish (Brock,
1954, fig. 1). In the eastern Pacific, if the size-
frequency samples presented by Hennemuth
(1957) are typical, the fishery depends on both
juvenile and adult fish. The Japanese skipjack
fishery probably exploits adult as well as juvenile
fish (Yabe, 1954; Yao, 1955).

SPAWNING SEASON

It would be relatively simple to determine the
spawning season of skipjack if all the ovaries
ripened at the same time and if ripe fish were
readily taken. Small numbers then could be
examined to follow the development of ova to the
time of spawning. My data show, however, the
presence of a diversity of developmental stages in
any one period; therefore, another method had to
be employed to define the spawning season.

The temporal distribution of skipjack possessing
ripe or advanced ovaries should give some indi-
cation of the spawning season, the implication
being that these fish are actively spawning or very
close to spawning. The percentage distribution
of skipjack by month of capture and stage of
development is presented in figure 3. Only those
larger than the size at first spawning, and there-
fore, presumably only adult fish, were used in this
analysis. All but one specimen in my collection

UILY DEVELOPING

DEVELOPING

ADVANCED

JULY

AUG.

SEPT.

OCT.

NOV.

DEC.
JAN.
FEB.

I
1

^__

— —

MAR.
APR.

MAI

JUNE

71 B

85 g

101 S

44
10
0 10 20 30 40 0 10 20 30 40 50 60 70 80 90 0 10 20 30 40 50
PERCENT

Figure li. — Seasonal distribution of early developing,
developing, and advanced skipjack.

U.S. FISH AND WILDLIFE SERVICE

were included. As indicated earlier, aside from
one running ripe fish, which was caught in January
1957, no ripe skipjack were available during the
periods of sampling. Those in the advanced stage
were found, however, in November, and January
to April. This suggests that their major spawning
season hi this area is from about November
through April.

The spawning season may be further defined by
determining the temporal distribution of non-
spawning; i.e., early developing skipjack. It was
noted earlier that some classified as early de-
veloping possessed ovaries that either (1) contained
only early developing ova, aside from a few
residual ova from a previous spawning, or (2)
contained ova that had reached the developing
stage but were apparently degenerating. These
observations suggest, that during certain periods
of the year the ovaries may revert to a dormant
or early developing stage. A few skipjack classi-
fied as early developing were found in November,
January, and February; however, the greatest
numbers occurred in April and May, the months
in which fish in the advanced stage were declining
in number or were totally absent. I assumed
that such a distribution of early developing and
advanced skipjack indicated a decrease in spawn-
ing activity during these 2 months. However,
the situation is probably more complex, since
skipjack in all stages of development were found
simultaneously, and fish with developing ovaries
were found in all months sampled. In all proba-
bility, scattered spawning occurs throughout the
year, but the peak activity is from November
through April (or, roughly, the Southern Hemi-
sphere summer). The results of a study of the
distribution of skipjack larvae in this area, de-
scribed by Nakamura and Matsumoto,1 sub-
stantiate this conclusion. The larvae were caught
in greater abundance contemporaneously with the
greatest numbers of fish with advanced ovaries.

Skipjack spawning seasons in other areas, as in
Hawaii, appear to be typically long. The season
in Hawaii extends from late February, March, or
April to the first part of September (Brock, 1954).
Schaefer and Orange (1956) indicated that skip-
jack spawn in the vicinity of the Re villa Gigedo
Islands from April to December, and that spawn-

ing is more intense in summer and fall. Con-
cerning the fish in the Philippines, Wade (1951, p.
469) states, "... there are indications that the
period from September to April, inclusive, may be
the principal spawning period." The spawning
season in the southern waters of Japan, however,
is relatively short. Yao (1955) postulated that
skipjack spawn during June-August in the waters
south of Kyushu and the Ogasawara area.

FREQUENCY OF SPAWNING

The presence of two or more modes in ova-size
frequency distributions and that of residual ova
in ovaries containing mature ova have been used
to hypothesize multiple spawning. Among in-
vestigators studying tuna, June (1953) concluded
on the basis of such evidence that yellowfin in
Hawaiian waters spawn more than once during a
season. So did Brock (1954) for Hawaiian skip-
jack, Yuen (1955) for the bigeye in the Pacific,
and Otsu and Uchida (1959) for the Pacific
albacore.

The ova-diameter frequency distributions for
skipjack in northeastern French Oceania were
typically bimodal, or sometimes multimodal in
the more advanced ovaries (fig. 4). Furthermore,
residual ova were found in ovaries of 23 of the 72
skipjack that were judged to be in the advanced
stage.

MacGregor (1957) discussed this problem of
multiple spawning in some detail in an analysis of
Pacific sardine fecundity. He disagreed with
several criteria that have been used in the past to

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■<,

MICROMETER EXITS

1 Nakamura, E. L. and W. M. Matsumoto. MS. Distribution of larval
tuna in Marquesan waters. Bureau of Commercial Fisheries Biological
Laboratory, Honolulu, Hawaii. (Manuscript.)

Figure 4. — Ova-diameter distribution for a developing
skipjack ovary.

SKIPJACK SPAWNING IN MARQUESAS AND TUAMOTU AREAS

483

hypothesize multiple spawning; he objected to the
criterion of the presence of two or more modes in
ova-size frequency distributions. He pointed out
that the presence of two or more such modes in
developing ovaries does not necessarily mean that
all the groups mature and that multiple spawning
will occur.

Support for MacGregor's contention may be
found in Yabe's (1954) work on skipjack in Jap-
anese waters. He noted that skipjack smaller
than 47 cm. had relatively large ovaries from June
to August, but that the relative size of the ovaries
decreased after September. He suggested that
the ovaries shrank without spawning having
occurred.

As noted earlier, my data also show some
ovaries that were classified as developing but
contained what appeared to be degenerating ova;
this finding, one may argue, is in agreement with
MacGregor's thesis. It also may be argued,
however, that these data merely indicate that there
may be a cessation of spawning during part of the
year and do not necessarily indicate that none of
the intermediate-sized ova will be spawned.
Furthermore, skipjack as small as 43 cm. possessed
advanced ovaries which also had residual ova from
a previous spawning. If their growth rate in this
area is similar to that of the species in Hawaii
(Brock, 1954), which is not entirely unreasonable
since skipjack in both areas seem to reach adult-
hood at about the same length, then these small
fish must have spawned no more than 3 or 4
months previously. Earlier than that they would
not have been large enough to be sexually mature.
These observations, although not conclusive, in-
dicate the possibility of multiple spawning within
a season for individual skipjack.

FECUNDITY

Four skipjack with fork lengths of 43 to 74 cm.
and with advanced ovaries were selected for
fecundity determinations. Small sections were
obtained from each of the ovaries and weighed to
the nearest thousandth of a gram. The number of
ova in the most advanced group in the sample was
determined and multiplied by the ratio of ovary
weight to sample weight to get an estimate of the
total number of mature ova in the ovary. The
results are presented in table 1, which also includes
results obtained by Yabe (1954) for skipjack in
Japanese waters. Estimates of the number of

ova extruded at one spawning ranged from 0.1
million to 2 million, with an indication that the
number spawned is related to the size of the skip-
jack, the larger fish spawning more ova. Joseph
(1963) made fecundity determinations for 42
skipjack taken from the eastern Pacific Ocean.
His estimates ranged from about 0.2 million to
1.5 million ova per spawning for skipjack with
total lengths from 61.4 to 71.5 cm. Within the
limits of his data, the size of the skipjack and the
number of ova per spawning seemed to be related.
Among some of the other tuna, a relation between
the number of ova spawned and size of fish was
found for the bigeye in the Pacific (Yuen, 1955)
and Hawaiian yellowfin (June, 1953).

Table 1. — Results of skipjack fecundity determinations

Fish length

Ovary
weight

Weight of
sample

Advanced
ova in
sample

Estimated

advanced

ova in ovary

(millions)

Centimeter
43.0

Oram

Gram
0.046

Number
195

Number

0.1

46.8 1

. 1

50.5 _ --

112

.089

330

56.2 >

67.9 .

202
303

.080
.029

352
192

75.0

2.0

i Data from Yabe (1954).

GONAD INDEX

Several investigators have discussed the possi-
bility of using the relative ovary weight (ovary
weight X103/fish weight) as a measure of maturity
of tuna; e.g., June (1953), Yuen (1955), and Otsu
and Uchida (1959). Schaefer and Orange (1956)
also used the relative ovary weight to measure the
maturity of skipjack, the only difference being
that they used the cube of fish length instead of
fish weight and a factor of 10s instead of 103.
They called this relation the "gonad index."

which is defined as t7./. = -^X108, where "G.I."

is the gonad index, "w" the weight of the ovaries
in grams, and "L" the fish length in millimeters.
Schaefer and Orange plotted the gonad index
against the 95th centile of the total ova-size
frequency distribution and found a linear relation,
the gonad index increasing with ova size, at least
in their Area II of the eastern Pacific.

I calculated the gonad index for all the skipjack
in my collection. Because only a sample of the
mosl developed group of ova was measured, their

484

U.S. FISH AND WILDLIFE SERVICE

mean sizes were plotted against the gonad index
in lieu of the 95th centile of the total ova-size
frequency distribution. This difference should
not affect greatly the comparison of my results
with those of Schaefer and Orange.

Figure 5 is a scatter diagram showing my
results, with the regression line obtained by
Schaefer and Orange for their Area II data
superimposed. Schaefer and Orange concluded
that the gonad index was a reasonably reliable
measurement of the degree of ova development;
however, the largest gonad index they found was
about 36, as compared to my 96. My data fit
Schaefer and Orange's regression line fairly well
up to a gonad index of 36. Above this value the
relation seems to break down. There is a big
overlap in gonad index between developing and
advanced ovaries; therefore, it was not possible to
make any inferences about the stages of develop-
ment of skipjack in this area from the gonad index.

STAGE OF SEXUAL DEVELOPMENT AND
SCHOOLING BEHAVIOR

As mentioned earlier, the sampling of skipjack
by pole-and-line fishing was such that each sample
represented fish captured from a single school.
This circumstance made it possible to examine

the within-scliool distribution of developmental
stages.

A gross examination of the data (table 2) indi-
cates that skipjack in the different stages of
development were not distributed randomly within
schools. Although fish in all stages of sexual
development were found simultaneously in certain
months, there was no instance in which all three
stages of development were found within a school.
Most of the schools were represented by skipjack
in a single stage of development. A contingency
test of homogeneity (Hoel, 1954, pp. 172-175) was
applied to the data, testing the hypothesis that,
with respect to stage of sexual development,
skipjack are distributed randomly within schools.
The probability (X2=510, df = 144) of obtaining
the observed distributions by chance alone was
less than 1 in 100. I conclude that there was
indeed a relation between schools and stage of
sexual development. The fact that fish of similar
stages of sexual development tended to occur
together, as well as the fact that those in several
stages of development were found in a number of
months, should be considered in the design of any
study of spawning. Obviously, examination of a
large number from only a few schools could lead
to erroneous conclusions.

UJ' —

Jjtfi

■a

-0.6

<
W

0.7 MM.

• .• •

* * „ *

» SCHAEFER 3 ORANGE (1956J

FIG. 10 (AREA II)

ADVANCED
DEVELOPING
EARLY DEVELOPING

40 50 60

GONAD INDEX

100

Figure 5. — Gonad index and mean diameter of largest group of ova.
SKIPJACK SPAWNING IN MARQUESAS AND TTJAMOTTJ AREAS

485

Table 2. — Numbers of skipjack, in each stage of development
in samples from single schools

School

2____

3...

10....

15...

16....

•23

30...

32...

38.

«...

42...

45...

56-—

60 >

61..

62...

65.........

71...

Total

Stage of sexual development

Early
developing

Developing

Advanced

Total

As far as could be determined, there is very little
in the literature regarding skipjack sexual de-
velopment and schooling behavior. What are the
causes of their apparent segregation by stage of
sexual development? One possibility may be that
skipjack about to spawn seek one another out,

486

resulting in schools of similarly developed indi-
viduals. This explanation appears reasonable, for
such a situation is probably more efficient for
spawning purposes than a random distribution of
spawning and nonspawning fish. Another expla-
nation is that skipjack schools are relatively stable
aggregations, with individuals in the group
responding similarly to the environment and,
therefore, developing similarly. However, on the
basis of his size analysis of skipjack schools in
Hawaii, Brock (1954) concluded that their com-
position is not stable. The pattern of tagged fish
returns in Hawaiian waters seems to substantiate
Brock's conclusion (Yamashita2). There probably
is no simple explanation for this phenomenon.
Undoubtedly there are many factors that influence
the schooling behavior of skipjack, and the ob-
served similarity of sexual development of the fish
in the schools is probably a manifestation of a
complex of factors.

SUMMARY

1 . This study is based on the microscopic exam-
ination of ova from 402 pairs of ovaries collected
from skipjack caught on exploratory fishing cruises
from August 1956 through June 1958 around the
Marquesas Islands and Tuamotu Archipelago.

2. The ova, ovaries, and skipjack were classi-
fied as being in the "early developing," "develop-
ing," "advanced," and "ripe" stages of develop-
ment according to the physical characteristics, of
the most developed group of ova. Early develop-
ing ova ranged in appearance from simple trans-
parent cells to cells with a well-developed nucleus ;
developing ova were opaque because of the dep-
osition of yolk; advanced ova were opaque or
semiopaque and contained a cluster of oil droplets
or a single well-developed oil globule; ripe ova were
almost perfectly spherical and transparent and
contained a distinct straw-colored oil globule.

3. Skipjack in the Marquesas and Tuamotu
areas are capable of first spawning when they are
about 43 cm. long.

4. Scattered spawning may occur throughout
the year, judging from the occurrence of develop-
ing skipjack in all months of sampling. The
major spawning season, however, appears to be
from November through April.

' Yamashita, Daniel T. Ms. Results of Hawaiian skipjack tagging. In
files of the Bureau of Commercial Fisheries Biological Laboratory, Honolulu,
(Manuscript.)

U.S. FISH AND WILDLIFE SERVICE

5. Although no conclusive statements can be
made about the frequency of spawning of indi-
vidual skipjack, the data indicate a possibility of
more than one spawning per season.

6. Estimates of fecundity of skipjack ranged
from 0.1 to 2 million ova per spawning.

7. It was not possible to make any inferences
about the stage of development from the gonad
index of skipjack.

8. A contingency test of homogeneity showed
that there was a relation between skipjack schools
and stage of sexual development; i.e., there was a
tendency for skipjack in similar stages of sexual
development to be found together in schools.

LITERATURE CITED

Brock, Vernon E.

1954. Some aspects of the biology of the aku, Katsu-
wonus pelamis, in the Hawaiian Islands. Pacific
Science, vol. 8, No. 1, pp. 94-104.

Clark, Frances N.

1934. Maturity of the California sardine (Sardina
caerulea), determined by ova diameter measure-
ments. California Division of Fish and Game,
Fish Bulletin No. 42, 49 pp.

Hennemdth, Richard C.

1957. An analysis of methods of sampling to deter-
mine the size composition of commercial landings of
yellowfin tuna (Neothunnus macropterus) and skip-
jack (Katsuwonus pelamis) . Inter-American Tropi-
cal Tuna Commission, Bulletin, vol. 2, No. 5, pp.
174-243.

Hoel, Paul G.

1954. Introduction to mathematical statistics. 2d
ed. John Wiley & Sons, Inc., New York, 331 pp.

Joseph, James.

1963. Fecundity of yellowfin tuna (Thunnus alba-
cares) and skipjack (Katsuwonus pelamis) from the
eastern Pacific Ocean. Inter-American Tropical
Tuna Commission, Bulletin, vol. 7, No. 4, pp. 257-
292.

June, Fred C.

1951. Preliminary fisheries survey of the Hawaiian-
Line Islands area. Part III — The live-bait skipjack
fishery of the Hawaiian Islands. U.S. Fish and
Wildlife Service, Commercial Fisheries Review,
vol. 13, No. 2, 18 pp. [Also as Separate No. 271.]
1953. Spawning of yellowfin tuna in Hawaiian waters.
U.S. Fish and Wildlife Service, Fishery Bulletin 77,
vol. 54, pp. 47-64.

MacGregor, John S.

1957. Fecundity of the Pacific sardine (Sardinops
caerulea). U.S. Fish and Wildlife Service, Fishery
Bulletin 121, vol. 57, pp. 427-449.

Mann, Herbert J.

1955. Construction details of improved tuna longline
gear used by Pacific Oceanic Fishery Investigations.

U.S. Fish and Wildlife Service, Commercial Fisher-
ies Review, vol. 17, No. 12, pp. 1-10. [Also as
Separate No. 422.]

Marr, John C.

1948. Observations on the spawning of oceanic
skipjack (Katsuwonus pelamis) and yellowfin tuna
(Neothunnus macropterus) in the northern Marshall
Islands. In Milner B. Schaefer and John C. Marr,
Contributions to the biology of the Pacific tunas,
pp. 201-206. U.S. Fish and Wildlife Service,
Fishery Bulletin 44, vol. 51.

Matsui, Kizo.

1942. Gonads of skipjack from Palao waters. U.S.
Fish and Wildlife Service, Special Scientific Re-
port—Fisheries No. 20 (1950). Translated from
Kagaku Nanyo, vol. 5, No. 1, pp. 117-122.

Matsumoto, Walter M.

1958. Description and distribution of larvae of four
species of tuna in central Pacific waters. U.S.
Fish and Wildlife Service, Fishery Bulletin 128,
vol. 58, pp. 31-72.

Orange, Craig J.

1961. Spawning of yellowfin tuna and skipjack in
the eastern tropical Pacific, as inferred from studies
of gonad development. Inter-American Tropical
Tuna Commission, Bulletin, vol. 5, No. 6, pp.
459-526.

Otsu, Tamio, and Richard N. Uchida.

1959. Sexual maturity and spawning of albacore in
the Pacific Ocean. U.S. Fish and Wildlife Service,
Fishery Bulletin 148, vol. 59, pp. 287-305.

Schaefer, Milner B., and John C. Marr.

1948. Spawning of yellowfin tuna (Neothunnus ma-
cropterus) and skipjack (Katsuwonus pelamis) in
the Pacific Ocean off Central America, with de-
scriptions of juveniles. In Milner B. Schaefer and
John C. Marr, Contributions to the biology of the
Pacific tunas, pp. 187-195. U.S. Fish and Wildlife
Service, Fishery Bulletin 44, vol. 51.

Schaefer, Milner B., and Craig J. Orange.

1956. Studies of the sexual development and spawn-
ing of yellowfin tuna (Neothunnus macropterus) and
skipjack (Katsuwonus pelamis) in three areas of the
eastern Pacific Ocean, by examination of gonads.
Inter-American Tropical Tuna Commission, Bulle-
tin, vol. 1, No. 6, pp. 283-349.

Shimada, Bell M.

1951. Juvenile oceanic skipjack from the Phoenix
Islands. U.S. Fish and Wildlife Service, Fishery
Bulletin 64, vol. 52, pp. 129-131.

Snedecor, George W.

1946. Statistical methods. 4th ed. The Iowa State
College Press, Ames, Iowa, 485 pp.

Wade, Charles B.

1950a. Juvenile forms of Neothunnus macropterus,
Katsuwonus pelamis, and Eulhynnus yaito from
Philippine seas. U.S. Fish and Wildlife Service,
Fishery Bulletin 53, vol. 51, pp. 395-404.
1950b. Observations on the spawning of Philippine
tuna. U.S. Fish and Wildlife Service, Fishery
Bulletin 55, vol. 51, pp. 409-423.

SKIPJACK SPAWNING IN MARQUESAS AND TUAMOTU AREAS

487

1951. Larvae of tuna and tuna-like fishes from Yao, Masakazu.

Philippine waters. U.S. Fish and Wildlife Service, 1955. On the ovaries of the skipjack, Katsuwonus

Fishery Bulletin 57, vol. 51, pp. 445-485. pelamis (Linnaeus), captured in the fishing grounds

along the Japanese coast. Translated from Bulle-

Yabe, Hihoshi. . , . L tin of the Tohoku Regional Fisheries Research

1954. A study on spawning of skipjack in the Laboratory, No. 5, pp. 43-52.

Satsunan Sea area. Translated from General View Yuen Heeny S. H.

of Fishery (Suisan Gaku no Gaikan), Japan Asso- 1955 Maturity and fecundity of bigeye tuna in the

ciation for the Advancement of Science (Nippon Pacific. U.S. Fish and Wildlife Service, Special

Gakujitsu Shinko Kai), Tokyo, pp. 182-199. Scientific Report— Fisheries No. 150, 30 pp.

|SS U.S. FISH AND WILDLIFE SERVICE

FOOD OF YOUNG-OF-THE-YEAR WALLEYES IN LAKE ERIE

By David R. Wolfert, Fishery Biologist (Research)

Bureau of Commercial Fisheries Biological Laboratory

Ann Arbor, Mich.

ABSTRACT

Stomach contents were examined for 794 young-of-
the-year (O-group) walleyes (Stizostedion vitreum
vitreum) captured by trawls at 17 locations in western
Lake Erie in June-November 1962. Food organisms
were found in 92.5 percent of the stomachs. Food
varied with geographic location and season of capture,
but within areas and seasons, selection for certain
species and sizes of prey was strong. Walleyes from the
extreme western end of Lake Erie fed primarily on
gizzard shad and alewives during the summer and

shifted to emerald shiners during the fall. The stomach
contents of walleyes from the Island region changed
from mainly yellow perch during the summer to emerald
shiners by the end of the year. Walleyes collected east
of the Islands had consumed only smelt and yellow
perch. The numbers of forage species caught with
walleyes in trawls showed little correlation with the
representation of these species in walleye stomachs.
Walleyes fed on the smallest individuals of each species
regardless of species preferences.

Among the fishes of primary economic im-
portance in Lake Erie, the cisco or lake herring
(Coregonus artedi) , the whitefish (C. clupeaformis) ,
the sauger (Stizostedion canadense) , and the blue
pike (S. vitreum glaucum) have become commercial-
ly unimportant, mostly in recent years. The last
remaining "high-priced" fish left to the industry —
the walleye (S. vitreum vitreum) — has also declined
to a remnant population which fluctuates widely
in abundance. The commercial catch (United
States and Canadian) of walleyes has declined
from a peak of 15,405,000 pounds in 1956 to a
low of 717,000 pounds in 1962. The decline has
been accompanied by demands for management
of the fishery to restore and maintain abundance.
Recent studies of the life history of the walleye
were begun in 1957 to provide information
essential to management. This report on feeding
of young-of-the-year (O-group) walleyes at var-

Note.— Approved for publication Oct. 14, 1964.

This research was completed at the Biological Field Station, Sandusky,
Ohio.

ious seasons of the year and at different loca-
tions in western Lake Erie is a contribution to
these studies.

MATERIALS AND METHODS

The contents were examined of 794 stomachs
from O-group walleyes of the 1962 year class col-
lected in western Lake Erie at 17 locations in
June-November 1962 (fig. 1). All collections
were from U.S. waters and were made during
routine trawling to ascertain the relative success
of the hatching and survival of commercial and
other species. The fish were caught in semi-
balloon bottom trawls by Bureau of Commercial
Fisheries vessels, Musky II (523 fish), Kaho (35),
and an outboard-motor boat (233), and the Ohio
Division of Wildlife vessel Explorer (3) . The wall-
eyes were preserved whole in 20 percent formalin
after then- abdomens had been slit; examinations
and measurements were made in the laboratory.
Food organisms were identified to the lowest
taxonomic level possible. Stomach contents

FISHERY BULLETIN: VOLUME 65, NO. 2

489

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10 NX m /-B

Statute Miles

Figure 1. — Map of western Lake Erie showing locations
where young-of-the-year walleyes were collected and
areas by which data were analyzed. Dots represent
collection locations.

were measured volumetrically by water displace-
ment in a cylinder graduated to 0.1 ml. Items
with a volume less than 0.1 ml. were listed as
"trace". The entire stomach contents of 176 wall-
eyes (41-74 mm. long) caught in June were ex-
amined with a dissecting microscope. No volu-
metric measurements were made of the food of
these fish.

Counts were made of the O-group fish of the
following species that were caught in the trawl
hauls with the walleyes: Gizzard shad (Dorosoma

cepedianum), ale wife (Alosa pseudoharengus) ,
American smelt (Osmerus mordax), emerald shiner
(Notropis atherinoides) , spottail shiner (N. hud-
sonius), trout-perch (Percopsis omiscomaycus) ,
white bass (Roccus chrysops), yellow perch (Perca
flavescens), and sheepshead or freshwater drum
(Aplodinotus grunniens).

Data on food are presented separately for each
of three areas in which walleyes were collected
(fig. 1). Although the boundaries are somewhat
arbitrary, each area differs ecologically from the
others and each has its own characteristic fish
fauna.

FOOD OF YOUNG WALLEYES IN DIF-
FERENT AREAS

The food of young-of-the-year walleyes in Lake
Erie varied with geographic location and season
of capture, but, within an area and season, selec-
tion for certain species and sizes of prey was strong.
In general, little correlation existed between the
numbers of various forage species present in the
same catches with walleyes and the representation
of these species in walleye stomachs.

Extreme Western Lake Erie (Area 1)

Food organisms were found in 94.7 percent of the
189 walleye stomachs (table 1). Gizzard shad
and alewives were the principal food in July.
Together they made up 72.7 percent of the total
volume; gizzard shad occurred in 30.6 percent and
alewives in 20.7 percent of the stomachs contain-
ing food. These species represented only 4.1 per-

Table 1. — Food of young-of-the-year wolleyes in extreme western Lake Eric in July, August, and October, 1962

[Expressed in percentage of total volume (PV) and percentage frequency of occurrence (PO). Percentage frequencies based on numbers of stomachs containing

food]

Dates of capture

Food item

July 17-24

August 14-10

October 15-18'

I nsecl

<0. 1

0.1

<0. 1

16.7
47.0
23.7

13.9
2.8

8.3
47.2
13.9

Fish:

32.7

20.7

99.7

100.0

40.0

1.6

10.0

15.4

30 6

9.0

53.2

Smelt

6.7
5.9

5.2
33.3

7 1

120

108

157

226

490

U.S. FISH AXD WILDLIFE SERVICE

Table 2. — Young-of-the-year fishes taken in the same trawl hauls as walleyes (1968)
[Expressed as percentage of total trawl catches in each Indicated period '; no data for Area 3 because walleyes east of the Islands were taken in large-mesh trawls]

Dates of capture

Yellow
perch

Emerald
shiner

Gizzard

shad

Alewife

Spottail
shiner

White
bass

Shceps-
bead

Trout-
ixrch

Smelt

July 17-24.,
Aug. 14-16.
Oct. 15-18..

June 25-27

July 2-18

July 25- Aug. 1.

Aug. 20-30

Sept. 18-19

Oct. 29-Nov. 1.

Extreme western Lake Erie (Area 1)

39.2
16.9
66.3

1.2

5.4
<.l

2.9
5.5
4.2

13.0
9.3
14.7

43.4

58.5
.9

0.1

3.6

0.4
12.4

0.3
.6

Island region (Area 2)

97.1
99.0
38.8
79.6
17.9
73.0

4.1
2.2

0.7
11.9
1.2

7.4
.1

<0. 1
.8

1.4
.6

0.1

30.8
12.7
47.2
19.3

2.5
.2
16.6
4.1
13.6
.4

1.1
<.l
5.9
1.9

0.2

.4
1.0
1.9

0.2

1.2
1.5
.6

Numbers of young-of-the-year walleyes caught are given in table 1 and table 4.

Cent of the total number of fish taken in the trawl
(table 2). In contrast, white bass made up 43.4
percent of the total number of O-group fish in the
trawl catches from which the walleyes were ob-
tained but none were found in walleye stomachs.
Yellow perch composed 39.2 percent of the trawl
catches but were in only 9.0 percent of the stom-
achs. The consumption of smelt and spottail
shiners was negligible. No emerald shiners had
been eaten.

Gizzard shad and alewives were being sup-
planted by other prey in stomachs of walleyes cap-
tured August 14-16. The volume of the two
species in stomachs had dropped to 40.4 percent
and the frequency of occurrence was only 13.9
percent for the gizzard shad and 8.3 percent for the
alewife. Emerald shiners had entered strongly
into the diet; they made up 47.0 percent of the
volume and occurred in 47.2 percent of the stom-
achs. Emerald shiners were scarce, nevertheless,
in trawl catches (0.4 percent of the total catches).
The number of gizzard shad and alewives com-
bined had increased to 10.9 percent of all fish
caught, even though they had decreased in im-
portance as food for walleyes. White bass, still
the most abundant forage species available, had
not been eaten.

The shift in food from gizzard shad and alewives
to emerald shiners was complete in October when
the identifiable stomach contents of 32 walleyes
contained only emerald shiners. Emerald shiners
had increased to 12.4 percent of the total catch
of trawls in mid-October. Young-of-the-year
yellow perch, although now the most available
forage fish (66.3 percent of the total trawl catches),

FOOD OF YOUNG WALLEYES IN LAKE ERIE

had not been eaten. Walleyes apparently sought
more emerald shiners as the gizzard shad and
alewives grew to a size that made them unsuitable
prey (table 3).

Insects were eaten most commonly in August
when the percentage frequencies of occurrence of
pupae and larvae of the midge Tendipes were 13.9
and 2.8 percent, respectively. Tendipes, however,
constituted a negligible amount of the total volume

Table 3. — Comparison of total lengths (mm.) of young-of-
the-year fish caught in trawls in extreme western Lake Erie
and those taken from walleye stomachs (1962)

July 17-24

Aug.

14-16

Oct.

15-18

Species and item

Trawls

Stom-
achs

Trawls

Stom-
achs

Trawls

Stom-
achs

Alewife:

Average length

Range of length

33-69

256

42
36-47

64-102

38-61

100

102

79-130
40

33-89

51-58

38-64

130

43-86

58-76

142

52-60

45-54

49-64

117

76-147

141

51-86

339

157

135-193

141-

109

61-142

53-94

58-91

166

104

69-157

66-97

219

Emerald shiner:

48-65

48-76

35-50

Gizzard shad:

Average length

Range of length ...

Sheepshead:

43-46

20-69

311

20-84

308

41-74

482

0
0

33-12

Smelt:

Average length

Range of length

Spottail shiner:

Average length

Range of length

White bass:

Average length

Range of length

Yellow perch:

Average length

Range of length

491

of food. No other insects were present in the
stomachs of walleyes from this area.

Island Region (Area 2)

Of the 562 walleyes collected from Area 2
(table 4) the late June sample of 176 individuals
(mean length 55 mm.) required special treatment.
All stomach contents of these small fish were
examined with a dissecting microscope. The
major food at this time was unidentifiable fish
fry (frequency of occurrence — 65.5 percent).
Many of the fry probaby were yellow perch but
positive identification was impossible, because of
their small size. Leptodora kindtii appeared in
16.5 percent of the stomachs. Consumption of
Diaptomus , Cyclops, and Daphnia was limited as
was also that of unidentifible midge larvae and
pupae. Ewers (1933) found Leptodora the most
common of the Entomostraca in the diet of young
walleyes and blue pike in western Lake Erie.
The stomachs of 23 walleyes caught in the latter
part of July 1929, and examined by Boesel '

1 Boesel, M. W. 1929. A preliminary report on the food of certain insect
feeding fishes of Lake Erie. MS., Department of Zoology, Ohio State
University, 30 pp.

contained 82.9 percent Entomostraca and 17.1
percent fish by volume.

The 61 walleyes captured July 2-18 had been
feeding entirely on fish fry. Yellow perch com-
prised 92.3 percent of the total volume. Seem-
ingly little other food was available to small
walleyes in this area at this season. Trawl catches
in which the walleyes were taken consisted of
99.0 percent O-group yellow perch.

Young-of-the-year walleyes in other lakes of the
Midwest consume large quantities of yellow perch.
Eschmeyer (1950) found yellow perch in 42.1
percent of the stomachs of O-group walleyes of
Gogebic Lake, Mich., during June 24 to July 10,
1941. Yellow perch also made up 68 percent of
the total volume of food. Yellow perch constituted
77 percent by volume of the stomach contents
of O-group walleyes in Mille Lacs Lake, Minn.,
in June-September (Maloney and Johnson, 1957).

The 219 walleyes taken July 25 to August 7
had eaten a diversity of organisms. Yellow perch
continued to be the major food (total volume —
64.3 percent; frequency of occurrence — 72.3 per-
cent). They were also the most available prey

Table 4. — Food of young-of-lhe-year walleyes in the Island region in June- November 1962

(Expressed In percentage of total volume (PV) and percentage frequency of occurrence (PO).

containing food]

Percentage frequencies based on numbers of stomachs

Dates of capture

Food item

June
25-27
PO i

July 2-18

July 25-Aug. 7

Aug. 20-30

Sept. 18-19

Oct. 29-Nov. 1

Algae

0.5

.5
1.9
2.9

1.9

1.5

16.5

Copepods:

Cladocerans:

Insects:

<0. 1

<.l

7.0
.5

<0. 1

1.8

2.4

3.4

<. 1

12.1
4.5
12. 1

1.5

64.3

B.1

3.3

4.2

1.4

72.3

Fish:

Emerald shiner _ ...

3.0
.8

3.5
1.8

9.3
28.0

22.9
17.1

93.0

88.8

Smelt

1.5

8.6

Yellow percli

1.5
65.6

92.3

7.7

58.6
55 2

91.5

84.2

60.4

65.7

7.0

11.1

4.8

31.0

4.7

19 3

8.6

11. 1

176
27
55

61
3

219

IT,

183

1
2 4

219

i Volumes not measured in this collection .

492

U.S. FISH AND WILDLIFE SERVICE

(38.8 percent, of all fish taken by trawl) . Although
gizzard shad and alewives made up 24.2 percent
of the total volume of food, they were present in
relatively few stomachs. Similarly, few spottail
shiners had been eaten (frequency of occurrence—
1 .4 percent) even though they were readily avail-
able (30.8 percent of the trawl catches). Emerald
shiners were not taken by the trawl but were in
3.3 percent of the stomachs. Tendipes pupae were
more prominent at this time than hi any other
period (frequency of occurrence — 7.1 percent).
Maloney and Johnson (1957) reported that dip-
terous larvae occurred in the stomachs of walleyes
taken in August in Lake Winnibigoshish, Minn.

Yellow perch made up the bulk of the food of
the walleyes captured in the Island area, August
20-30 (total volume — 91.5 percent; frequency of
occurrence — 84.2 percent). Gizzard shad had
almost disappeared from the stomachs (total
volume — 0.8 percent). Again, emerald shiners
had been eaten but were not in the trawl catches.
Walleyes may have been seeking out this minnow.
On the other hand, trawl catches may not provide
an exact index of relative abundance of emerald
shiners because this fish occasionally frequents
the surface waters and hence becomes unavailable
to bottom trawls.

The importance of yellow perch had begun to
decline by September 18-19 (total volume — 60.4
percent; frequency of occurrence — 65.7 percent);
perch were being supplanted by emerald shiners
(total volume — 9.3 percent; frequency of occur-
rence— 22.9 percent). Trawl catches indicated
that the availability of yellow perch had decreased
while that of the emerald shiners had increased
(table 2).

The few walleyes caught between October 29
and November 1 showed a further shift from
yellow perch (total volume— 7.0 percent; fre-
quency of occurrence — 11.1 percent) to emerald
shiners (total volume — 93.0 percent; frequency of
occurrence — 88.8 percent). Doan (1941) stated
that emerald shiners constituted 82 percent of the
volume of food eaten by 62 walleyes, 10-17 inches
long, caught at Put-In-Bay, Ohio, in November
and December 1940.

Evidence from extreme western Lake Erie (Area
1) suggests that the walleye prefers gizzard shad

or alewives (luring it s early months of life, even
though ample numbers of young yellow perch
(and other species) of suitable size are available.
It is apparent from the fish taken in the Islands
region (Area 2), however, that where yellow perch
almost completely dominate the food supply, the
walleye can and does feed heavily upon them.
The shift to emerald shiners that occurred in the
late summer and autumn in both Areas 1 and 2
may be traceable to different causes. In Area 1 ,
the emerald shiners became prominent in the food
of walleyes when the gizzard shad and alewives
became too large to eat. In Area 2, the change
probably reflects species rather than size pref-
erence since both the emerald shiners and the
yellow perch captured in October were about the
same size (table 5).

East of the Island Region (Area 3)

Forty-three O-group walleyes were collected
off Huron and Vermilion, Ohio, and east of Kelleys
Island in July, August, September, and October.
The 38 fish that had food in then- stomachs had
eaten almost exclusively smelt and yellow perch
(table 6). Yellow perch were the only food of
walleyes in the small July collection. Some smelt
were eaten in August, and by September this
species had become the only food in almost all
stomachs. No suitable records are available of
the relative numbers of O-group fish living with
the walleyes because most were taken in trawls
with large-mesh cod ends that permitted the
escape of most small fish. A cursory examination
of the catches did reveal, however, that the bulk
of forage available to the walleyes east of the
Islands consisted of smelt and yellow perch in all
seasons.

ACKNOWLEDGMENTS

The Bureau of Commercial Fisheries vessel
Kaho and the Ohio Division of Wildlife vessel
Explorer collected walleyes for stomach analysis.
Jarl Hiltunen assisted in the identification of the
immature midges, and LaRue Wells helped iden-
tify crustaceans. Vernon C. Applegate advised
in the preparation of the manuscript.

FOOD OF YOUNG WALLEYES IN LAKE ERIE

493

Table 5. — Comparison of total lengths (mm.) of young-of-the-year fish caught in trawl

from walleye stomachs {1962)

in the Island region and those taken

Species and item

July 2-18

July 25-August 7

August 20-30

September 18-19

Oct. 29-Nov. 1

Trawls

Stomachs

Trawls

Stomachs

Trawls

Stomachs

Trawls

Stomachs

Trawls

Stomachs

Alewife:

Average length

28-61

111

64-89

46-59

37-15

44-64

61-117

Range of length...

44
44

43-55

57-75

56-76

100

Emerald shiner:

58-117

174

30-99

193

102

61-147

253

Gizzard shad:

Sheepshead:

30-40

27-40

46-58

38-74

158

41-79

152

48-76

171

45-53

Smelt:

25-515

25-56

126

30-51

121

28-58
209

28-81

298

30-76

573

51-71

104

109

51-147

209

56-91

51-91

53-124

53-94

186

Spottail shiner:

White bass:

23-28

26-46

42-61

43-64

Yellow perch:

Table 6. — Food of young-of-the-year walleyes captured in Area 3 in July, August, September, and October, 1962

[Expressed in percentage of total volume (PV1 and percentage frequency of occurrence (PO). Percentage frequencies based on numbers of stomachs containing

food]

Dates of capture

Food item

July 19

Aug. 23-30

Sept. 6-26

Oct. 10

PV PO

Smelt.

16.1
83.9

50.0
100.0

93.3

63.6

95.7
4.3
<.l

90.9

100.0

4.5

Unidentifiable fish remains

36.4

4.5

1
82

1"4

2 S

2.W

LITERATURE CITED

Doan, Kenneth H.

1942. Some meteorological and limnological con-
ditions as factors in abundance of certain fishes in
Lake Erie. Ecological Monographs, vol. 12, pp.
293-314.

Eschmever, Paul H.

19.50. The life history of the walleye, Stizosledion
vitreum vitreum (Mitchill), in Michigan. Michigan
Department of Conservation, Bulletin, Institute
for Fisheries Research, No. 3, 99 pp.

494

Ewers, Lela A.

1933. Summary report of Crustacea used as food by
the fishes of the western end of Lake Erie. Trans-
actions of the American Fisheries Society, vol. 63,
pp. 379-390.

Maloney, J. E., and F. H. Johnson'.

1957. Life histories and inter-relationships of walleye
and yellow perch, especially during their first
summer, in two Minnesota lakes. Transactions of
the American Fisheries Society, vol. 85 (1955),
pp. 191-202.

U.S. FISH AND WILDLIFE SERVICE

EFFECT OF THE SPAWNING BED ENVIRONMENT ON REPRODUCTION

OF PINK AND CHUM SALMON '

By William J. McNeil, Fishery Biologist (Research)

Bureau of Commercial Fisheries Biological Laboratory

Auke Bay, Alaska

ABSTRACT

Mortality of 5 brood years of pink salmon, Oncorhyn-
ch us gorbuscha, and chum salmon, 0. keta, in spawn-
ing beds of three Southeastern Alaska streams was
studied. Eggs and larvae were sampled periodically,
and mortality was associated with certain environ-
mental factors: The supply of dissolved oxygen, the
stability of spawning beds, and freezing.

Total mortality between spawning and fry emergence
typically varied between 75 and 99 percent in the study
areas. High mortality occurred during low and high
stream discharge and freezing air temperatures. Mor-
talities ranging from 60 to 90 percent of deposited eggs
occurred in association with low dissolved oxygen levels
during and after the spawning period. Movement of
gravel in certain instances was associated with the
removal of 50 to 90 percent of eggs and larvae present

in spawning beds. Freezing caused up to 65 percent
mortality of eggs and larvae in one stream.

Low dissolved oxygen levels occurred once in 5 years.
This occurrence was associated with unusually low
water during spawning in late summer. Mortality
during periods of heavy precipitation was highly vari-
able. In one instance, a 90-percent mortality occurred
where wood debris was deposited within the high water
channel. Wood debris floating over spawning beds
was not damaging to eggs and larvae. There were
several instances where mortality estimated at almost
50 percent occurred with no evidence that deposited
wood debris shifted position. High mortality from
freezing occurred only in the stream having the lowest
minimum discharge.

Pink salmon, Oncorhynchus gorbuscha, and chum
salmon, 0. keta, are the only species of Pacific
salmon in North American streams using fresh
water 2 solely for spawning. The young of these
species, with minor exceptions, migrate to sea soon
after emerging from spawning beds, while the
young of chinook salmon, 0. tshawytscha; soc.keye,
0. nerka; and coho, 0. kisutch, may remain in
fresh water for many months.

Note. — Approved for publication Nov. 19. 1964.

1 This research was done while the author was a Research Associate at the
Fisheries Research Institute, University of Washington, Seattle, Wash,
and was financed by the Bureau of Commercial Fisheries under Contract
Nos. 14-17-008-29, 14-17-008-96, 14-17-0005-20, and 14-17-0005-31, with funds
made available under the Act of July 1, 1954 (68 Stat. 376), the Saltonstall-
Kennedy Act. This report constitutes Contribution No. 198, College of
Fisheries, University of Washington, Seattle, Wash.

2 Includes intertidal areas periodically inundated by salt water or brackish
water.

Adult pink and chum salmon commonly migrate
into coastal streams to spawn in summer and early
autumn. They excavate pockets in riffle areas
and deposit and bury their eggs in the bottom.
Surviving embryonic and larval salmon remain in
the spawning bed for periods up to 8 months, and
fry usually emerge and migrate seaward the spring
after spawning.

The spawning bed protects eggs and larvae
against predators, light, displacement, and me-
chanical injury. Despite this protection, mortal-
ity from time of egg deposition to fry emergence
commonly exceeds 75 percent.

Estimates of total fresh-water mortality of pink
and chum salmon have been published for Mc-
Clinton, Morrison, Nile, and Hook Nose Creeks,
British Columbia (Pritchard, 1948; Neave, 1953;

FISHERY BULLETIN: VOLUME 65, NO. 2

495

Hunter, 1959); and Sashin Creek, Southeastern
Alaska (Merrell, 1962). For the brood years
studied, total mortality in these streams ranged
from 76 to 99.9 percent. Although these esti-
mates fail to differentiate among mortalities oc-
curring during (1) adult migration, (2) egg and
larval development, and (3) fry migration, other
evidence indicates that the largest portion of total
fresh-water mortality occui's between the time
eggs are deposited and fry emerge.

Typical results are seen in mortality studies at
Hook Nose Creek (Hunter, 1959). Although
Hunter found that total deaths varied consider-
ably from year to year, losses before spawning
appeared to be consistently small. The number
of fry consumed by predators was fairly constant
from year to year and was usually a small frac-
tion of the potential egg deposition. Most deaths
occurred between spawning and fry emergence.
Hunter's data showed that over a 10-year period,
69-94 percent of the eggs potentially available
for deposition were lost before emergence of fry.

Increased utilization of streams and watersheds
by logging, mining, and other multiple-use activi-
ties has caused concern about the welfare of
salmon. A thorough understanding of the factors
causing mortality in spawning beds will be re-
quired to evaluate the effects of multiple-use
activities on pink and chum salmon.

In 1956 the Bureau of Commercial Fisheries
gave Saltonstall-Kennedy Act funds to the Fish-
eries Research Institute (FRI), University of
Washington, to study the effects of logging on
pink salmon streams in Alaska. These studies
concentrated on identifying the time and magni-
tude of mortality and determining the factors
responsible. This paper reviews past work on
factors causing mortality in spawning beds and
reports findings of field studies in three South-
eastern Alaska spawning streams. Field obser-
vations on mortality and associated environmental
factors thought to cause mortality are described.

REVIEW OF ENVIRONMENTAL REQUIRE-
MENTS OF EGGS AND LARVAE

Given an environment free of mechanical dis-
turbances, the growth, development, and survival
of salmon eggs and larvae depend largely upon
physical and chemical characteristics of the sur-
rounding water. Properties of water that affect
eggs and larvae include temperature, dissolved

oxygen content, velocity, mineral and waste meta-
bolite content, and osmotic pressure.

The spawning bed environment is greatly influ-
enced by weather and characteristics of the
streambed, stream, and watershed. The quality
of intragravel water 3 is influenced in part by the
hydrological regimen. Environmental changes
within spawning beds can accompany changes
in tide level, precipitation, and air temperature.
Periods of spawning and development very likely
coincide with the seasonal conditions that offer
maximum opportunity for survival of the young
salmon.

SOURCES OF INTRAGRAVEL WATER

To survive, eggs and larvae must receive an
ample supply of oxygenated water suitable in
temperature and free of toxic substances. The
source of intragravel water may govern to a large
extent its physical properties and its suitability
for eggs and larvae.

Ground water and surface stream water are the
two primary sources of intragravel water. In
spawning beds of pink and chum salmon, surface
stream water is the primary source of intragravel
water (Sheridan, 1962a), while in spring-fed
spawning beds commonly used by other salmonid
species; e.g., sockeye salmon, ground water may
be an important source of intragravel water.

Vaux (1961, 1962) showed that interchange be-
tween stream and intragravel water occurred when
certain hydraulic requirements of the stream and
streambed were satisfied. He formulated models
which showed the direction of interchange depends
on the curvature of the gravel surface profile.
Where the profile was concave, water upwelled;
where it was convex, a downdraft occurred. In
the absence of curvature, there was no inter-
change, provided permeability and gravel lied
depth did not vary. Vaux verified these relations
with field and laboratory experiments. Figure 1
illustrates the direction of interchange with change
in curvature of the stream bottom.

WATER TEMPERATURE

Water temperature controls the rate of growth
and the developmental and metabolic processes of
the salmon embryo. It also affects other water
quality characteristics, such as dissolved oxygen
concentration.

» The term "intragravel water" refers to water occupying interstitial spaces
within the streambed.

496

U.S. FISH AND WILDLIFE SEKVICE

CONVEX PROFILE

CONCAVE PROFILE

SPAWNING BED

Figure 1. — Changes in direction of interchange with
changes in curvature of the stream bottom (from Vaux,
1962). Arrows indicate direction of interchange.

The temperature of intragravel water in pink
salmon spawning beds is controlled largely by
stream water temperature. Sheridan (1961)
obtained a linear correlation coefficient of 0.99
when he related intragravel and stream water
temperatures.

Pink and chum salmon embryos and larvae
survive in streams where water temperatures drop
to 0° C. James (1956) reported water tempera-
tures slightly below 0° C. in pink and chum salmon
spawning streams. In an experiment with pink
salmon embryos, Combs and Burrows (1957)
varied water temperature to coincide with varia-
tions observed in Sashin Creek, Southeastern
Alaska. They found that embryos reared at
5.5° C. for 30 days and then at 0.5° C. to hatching
had almost no mortality.

Information is lacking on tolerance of pink and
chum salmon eggs and larvae to high tempera-
ture, but studies with other salmonid species
suggest that temperatures of 15° C. or higher may
be tolerated. Chinook salmon embryos exposed
to 20° C. water died at all developmental stages,
while embryos exposed to 17° C. water died only
at hatching (Donaldson, 1955). Larvae of Atlan-
tic salmon, Salmo salar, and brown trout, S. trutta,
survived 16 days in 20° C. water (Bishai, 1960).

Pink and chum salmon normally spawn on
declining water temperature after maximum sum-
mer temperatures. Sheridan (1962b) reported
that pink salmon typically spawned in South-
eastern Alaska streams after water temperatures
declined to 10° C. or less in late summer. Mean
water temperature in Hook Nose Creek was
reported to be 12° C. or less when pink and chum
salmon spawned (Hunter, 1959). It would appear,

therefore, that high temperature seldom exerts a
direct lethal stress on pink and chum salmon eggs
and larvae.

DISSOLVED OXYGEN SUPPLY

Oxygen is transported to the embryo by diffu-
sion. After water hardening, the capsule of a
newly fertilized egg is permeable to oxygen mole-
cules but impermeable to water molecules (Krogh
and Ussing, 1937).

The oxygen consumption rate per unit mass of
embryonic tissue appears fairly constant over most
of the developmental period. During the last
two-thirds of the period, the oxygen consumption
per gram of embryo remained almost constant for
Atlantic salmon (Hays, Wilmot, and Livingstone,
1951). The rate of oxygen consumption for chum
salmon was highest but variable during the first
one-third of the developmental period and fairly
constant thereafter (Alderdice, Wickett, and
Brett, 1958).

The rate at which oxygen is consumed by salmon
embryos decreases with decreasing dissolved
oxygen content of the water below a certain "limit-
ing level" while at dissolved oxygen levels higher
than the limiting level, the rate is independent of
pressure or content of dissolved oxygen. The
limiting level corresponds to the dissolved oxygen
content or partial pressure below which normal
metabolic functions are affected. There is evi-
dence, also, that the limiting level may vary in a
complex manner with temperature and stage of
development (Lindroth, 1942; Hays, Wilmot, and
Livingstone, 1951).

Alderdice, Wickett, and Brett (195S) calculated
theoretical values of the limiting dissolved oxygen
level for chum salmon embryos by using an equa-
tion originated by Harvey (1928) and later
modified by Krogh (1941). The equation is

CD=

SKT

(1)

where delimiting level of oxygen dissolved in the
external medium in atmospheres
i?=radius of the egg in cm.
S=ml. of oxygen consumed/g. of embryo/

minute.
T= thickness of the capsule in cm.
U= diffusion coefficient of oxygen through the
capsule in ml. 02/cm.2 of surface/cm. of
thickness/minute.

.SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON
774-711 O— 66 14

497

DO
<

t 5

P 4
<

I-

UJ :>
o 0

z
o
o

O
CO

THEORETICAL CURVE FOR-

CHUM SALMON (NEGATIVE

CURVATURE)

V f!

/
/ •

U-
lo

OBSERVED CURVE FOR

ATLANTIC SALMON
(POSITIVE CURVATURE)

0 100 200 300 400 500 600

STAGE OF DEVELOPMENT

(CENTIGRADE- DEGREE- DAYS)

Figuhe 2. — Concentration of dissolved oxygen first
reducing rate of oxygen consumption by salmon embryos.
Upper curve is from Alderdice et al. (1958). Lower
curve is from Hays et al. (1951). Water temperature is
taken to be 10° C, and a centigrade-degree-day is
equivalent to a constant temperature of 1° C. above 0°
C. over a 24-hour period.

In figure 2, the theoretical values of C0 at 10° C.
obtained for chum salmon by Alderdice etal. (1958)
(upper curve) are compared with limiting levels
determined experimentally for Atlantic salmon by
Hays et al. (1951). The most striking difference
between theoretical and observed limiting dis-
solved oxygen concentrations is the sign of curva-
ture of the connected points. It is doubtful if
difference in species would account for positive
curvature in Atlantic salmon and negative curva-
ture in chum salmon. The validity of equation (1)
as it applies to salmonid embryos is, therefore,
questioned.

Wickett (1954) pointed out that the delivery rate
of oxygen to an egg or a larva is a function of water
velocity as well as oxygen content . Others (Coble,
1961 ; Shumway, 1960; Silver, 1960; Silver, Warren,
and Doudoroff, 1963) gave experimental evidence

that variations in velocity affected embryonic
growth, development, and survival in much the same
manner as variations in oxygen content.

According to curves of figure 2, embryos are most
susceptible to low dissolved oxygen levels near the
time of hatching. Evidence of this was presented
by Hays and Armstrong (1942) and Garside
(1959), who observed high mortality at hatching.
Because mortality increased with slight increases in
temperature, these authors attributed death to an
inadequate amount of dissolved oxygen diffusing
through the egg capsule.

The effect of oxygen supply rate on growth,
development, and survival of salmonid embryos
has been investigated by several workers. The
dissolved oxygen level causing 50-percent mortality
of chum salmon embryos increased from about
0.4 mg./l. at fertilization to 1.4 mg./l. at hatching,
when apparent velocity * and temperature were
maintained at 85 cm. /hour and 10° C. (Alderdice
et al., 1958). Coho salmon eggs incubated at
near true velocity of 3 cm./hour, a temperature of
9° C, and an ox37gen level of 2.4 mg./l. survived to
hatch but produced larvae about one-third the
volume of controls (Shumway, 1960). Similar
findings were reported by Silver, Warren, and
Doudoroff (1963), who experimented with chinook
salmon and rainbow trout, Salmo gairdneri,
embryos. At near true velocity of 6 cm./hour
and a dissolved oxygen content of 2.6 mg./l.,
Silver (1960) observed abnormal development .
At similar low levels of dissolved oxygen, Alderdice
et al. (1958) and Garside (1959) described ab-
normal development of caudal regions during
somite formation. Garside also found that the
development rate was retarded significantly by
reduced oxygen level.

Larvae are more tolerant of low dissolved
oxygen levels than are embryos. For Atlantic
salmon, Hays et al. (1951) found the dissolved
oxygen concentration limiting metabolism of
embryos to be 7.5 mg./l. at 10° C. After the
eggs hatched the limiting concentration decreased
to 4.5 mg./l. Initiation of active respiration
across gill membranes having vastly increased
respiratory areas may have caused the sudden
decrease in limiting oxygen concentration.

1 Apparent velocity is measured by dividing the rate of flow by the cross-
sectional area ot the lied through which the water had passed. The actual
or true velocity is greater than the apparent velocity where part of the cross-
sectional area is occupied by eggs or other objects.

4! is

U.S. FISH AND WILDLIFE SERVICE

Several general conclusions may be drawn
regarding the dissolved oxygen requirements of
pink and chum salmon embryos and larvae.
First, the supply of dissolved oxygen made
available to an embryo or larva is both a function
of dissolved oxygen content and flow velocity of
intragravel water. Second, the rate of oxygen
consumption per unit mass of embryonic tissue
is little affected by growth over most of the
developmental period up to hatching. Hence,
the rate of oxygen consumption by a population
of embryos is possibly a simple function of the
biomass present. Third, oxygen levels limiting
metabolic processes and causing mortality ap-
proach a maximum shortly before hatching. After
hatching, there is a sharp decline in limiting levels
of dissolved oxygen. By considering only the
requirements of eggs and larvae and neglecting
changes in the environment, it would appear that
the dissolved oxygen requirements of eggs become
most critical at hatching.

METABOLIC WASTE PRODUCTS

Two metabolic waste products excreted by
salmon eggs and larvae are free carbon dioxide and
ammonia. Both are toxic to aquatic organisms.

The effect of free carbon dioxide on the physiol-
ogy of blood has been studied exhaustively.
Jacobs (1920) showed that molecules of free
carbon dioxide passed readily through living cell
membranes. The ability of eggs and larvae to
respire is influenced by the blood's affinity for
oxygen, and there is a loss of affinity for oxygen in
the presence of free carbon dioxide (Bohr effect).
Salmonid blood in vitro lost half of its oxygen-
combining capacity in the presence of 150 mg./l.
of free carbon dioxide at 15° C. (Irving, Black, and
Safford, 1941). Since the oxygen tension equal
to one-half saturation is considered to be the mini-
mum compatible with exchange of oxygen to the
tissues, a salmonid having its blood oxygen-
combining capacity reduced 50 percent would die
theoretically of suffocation.

Only a few investigators have investigated the
effect of free carbon dioxide on salmonid eggs and
larvae. Bishai (1962) induced a marked meta-
bolic stress on Atlantic salmon and brown trout
larvae by subjecting them to high free carbon
dioxide levels. High mortality among trout em-
bryos occurred at free carbon dioxide levels be-

tween 55 and 80 mg./l. in hatchery water (Surber,
1935). Increased mortality of chum salmon em-
bryos was caused by 125 mg./l. of free carbon
dioxide (Alderdice and Wicket t, 1958). Addi-
tional information on the effect of high free carbon
dioxide content in conjunction with low dissolved
oxygen levels on growth, development, and sur-
vival of salmon eggs and larvae will be required
before relationships observed between mortality
and quality of intragravel water can be fully
evaluated.

Ammonia is the most toxic metabolite. Am-
monia excreted by salmon eggs and larvae is
removed by the surrounding water, but it is
possible that toxic concentrations of ammonia
occur where the density of eggs and larvae is high
and the circulation of intragravel water is poor.

The toxicity of ammonia is related directly to
the concentration of free ammonia (NH3) or non-
ionized ammonium hydroxide (NH3-H20) in solu-
tion. Ionization of NH3H20 occurs according to
the equilibrium equation

NH3H2O^NH ++OH-

Ionization is nearly complete at pH 7.0 and lower,
and ammonia is least toxic in waters having high
concentrations of hydrogen ions (pH <C7.0). For-
mation of carbonic acid from respired free carbon
dioxide would, therefore, tend to decrease the
toxicity of ammonia.

Reviews of influence of ammonia on fish have
been given by Doudoroff and Katz (1950) and
Doudoroff (1957). These authors concluded that
additions of 2 to 7 mg./l- of ammonia to natural
waters could kill fish. Experiments by Wuhr-
mann and Woker (1948) showed that concentra-
tions of only 1.2 mg./l. of NH3 were lethal to
fresh-water fish of the genus Squalius. They also
found that 1.3 mg./l. of NH3 killed rainbow trout
fry.

According to Wolf (1957a, 1957b), blue-sac
disease was induced by subjecting salmonid em-
bryos to high concentrations of ammonia. The
incidence of disease was roughly proportional to
the contact period and the NH3 concentration.

SALINITY

Pink and chum salmon spawn in intertidal areas
of streams, and in some streams more fry are

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

499

produced in intertidal areas than in upstream
areas (Kirkwood, 1962). From field observation
alone, it is apparent that pink and chum salmon
eggs and larvae can tolerate intermittent high
salinity.

Rockwell (1956) exposed pink and chum salmon
eggs and larvae to constant high salinity and found
no evidence that fertilization of eggs was affected
by salinities up to 18%0. The tolerance of
embryos to sea water was a function of osmotic
pressure, time of exposure, and stage of develop-
ment. Mortality was attributed to dehydration.
He found a marked reduction in the rate of early
growth of chum salmon embryos at constant
salinities of 12%o and greater and a total mortal-
ity to hatching at a salinity of 12%o. At 6%0
salinity, survival to hatching was less than thai
in the controls.

Larvae are more tolerant of high salinity than
eggs. According to Rockwell (1956), salinities as
high as 18% o killed few pink salmon larvae.
Chum salmon larvae were less tolerant, some dying
at a salinity of 12°/oo-

Salinity of intragravel water in pink and chum
salmon intertidal spawning beds is influenced
markedly by tidal action. Hanavan and Skud
(1954) found salinity of intragravel water of pink
salmon spawning beds corresponds closely to
salinity of overlying water. Also, they observed
high survival of pink salmon eggs and larvae where
tidal inundation prevailed during 35 percent of the
incubation period. Ahnell (1961) observed that
the salinity of intragravel water remained high
for a period after the tide had receded and after
fresh water had flowed over the streambed. He
found also that high salinity of intragravel water
was frequently associated witli low dissolved
oxygen concentration.

The effect of salinity on pink and chum salmon
fry production is still poorly understood, although
highly productive spawning areas exist in inter-
tidal zones of streams (Kirkwood, 1962). Eggs
and larvae of both species can tolerate intermit-
tent high salinity, but tolerance levels have not
yei been defined. Also, the retention of sail water
by spawning beds and the influence of salt water
on temperature, oxygen levels, and water velocity
have not been studied in detail. The ultimate

need is to determine the relative potential of
intertidal and upstream areas to produce fry.

500

PERMEABILITY OF BOTTOM MATERIALS

It has already been pointed out that the oxygen
delivery rate to an egg or larva is a function of
both the oxygen content and velocity of intra-
gravel water. Apparent velocity of water flow-
ing within the streambed can be described by the
equation.

v=vi (2)

Where v= apparent velocity,

jj = permeability coefficient, and
i= hydraulic gradient.

According to tins equation, apparent velocity
of intragravel water varies directly with the perme-
ability of materials through which it passes.
Other factors being equal, the permeability of
bottom materials in spawning beds should be
directly related to their potential to produce
salmon fry; Wickett (1958) gave evidence that
the average survival of pink and chum salmon eggs
and larvae in four British Columbia streams was
directly related to the permeability of bottom
materials (fig. 3).

The permeability of bottom materials is a
function of particle compaction, arrangement,
and size. McNeil and Ahnell (1964) showed that
the permeability of bottom materials in a pink
salmon spawning bed is inversely related to the
fraction of fine particles composing the total
volume of the bed. Thus, the resistance to flow
caused by the presence of fine particles in salmon
spawning beds must govern, to a large extent,
their potential to produce healthy fry.

0 40 80 120 160

PERMEABILITY OF STREAMBED GRAVELS ICM./MIN.)

Figi re 3.— Observed relation reported by Wickett (1958
between permeability and survival of pink and chum
salmon to migrant fry.

U.S. FISH AND WILDLIFE SERVICE

STABILITY OF SPAWNING BEDS

Dislodgment of salmonid eggs and larvae from
spawning beds during high water has been de-
scribed by a number of workers (Hobbs, 1937:
Hutchinson and Shuman, 1942; Davidson and
Hutchinson, 1943; Withler, 1952; Needham and
Jones, 1959; Wickett, 1959). Estimates of mor-
tality rates from gravel movement have not been
made in most instances. Furthermore, little is
known about the interactions of factors creating
unstable conditions in spawning beds and causing
mortality rates to increase.

( Ihanges in surface profile occur where a stream-
bed degrades or aggrades. It is possible, however,
for bed movement to occur without an associated
change in surface profile or gradient (Mackin,
1948). One important unsolved problem is to
determine if bed movement can cause appreciable
mortality where there is no associated change in
streambed gradient.

The effect of the pool-riffle complex on the
capacity of streams to produce pink and chum
salmon is not yet well understood. Factors im-
portant in generating the pool-riffle complex
include debris in the high-flow channel (Bishop
and Shapley, 1963) and bends in the channel.
Shifts in position of debris create unstable condi-
tions in the spawning bed which could lead to
dislodgment of salmon eggs and larvae.

METHODS
STUDY STREAMS

Field studies described in this report were con-
ducted mostly in three streams located in the
Kasaan Bay region of Prince of Wales Island,
Southeastern Alaska: Harris River, Indian ("reek,
and Twelvemile Creek (fig. 4). Watersheds of the
study streams are precipitous. Soils are shallow
and underlaid with impermeable materials. Ex-
cept for muskegs, which are poorly drained areas,
the watersheds have a very low capacity to retain
water. Runoff is rapid, and peak discharges
occur within a few hours after the beginning of
heavy rainfall. These high discharges occur
mostly in autumn.

The study streams occasionally freeze over in
winter, when water temperatures near 0° C. have
been recorded for as long as 6 consecutive days;
summer water temperatures rarely exceed 13° C.
(James, 1956).

Adult pink and chum salmon usually enter the
study streams to spawn between mid-August and
late September. Spawning occurs mostly in
September. A large percentage of pink salmon
spawn in intertidal areas, where the density of
spawners is highest in most years.

Harris River is the largest of the three study
streams. Salmon have access to about an 8-mile
section of the main stream and its North Fork.
Chum salmon were observed to spawn mostly in
the North Fork, but pink salmon exhibited a
marked preference for a %-mile section of the upper
intertidal zone. Discharge during the spawning
period commonly fluctuates between 22 and 1,800
cubic feet per second (c.f.s.). During autumn
storms, average daily discharge may approach
5,000 c.f.s. Width of intertidal spawning riffles
during low flow averages about 60 feet. Spawning
beds consist of materials mostly less than 4 inches
in diameter.

Indian Creek is the smallest of the study streams
but exhibits pronounced fluctuations in discharge.
During the spawning period, discharge commonly
varies between 4 and 300 c.f.s. Average daily
discharge during autumn storms approaches 900
c.f.s. some years, and a peak instantaneous
discharge of 6,400 c.f.s. was recorded on one
occasion (McNeil, Shapley, and Bevan, 1962).
Pink salmon spawn in Indian Creek, primarily
in an intertidal section one-fourth mile long be-
ginning at the confluence with Harris River.
The average width of Indian Creek spawning-
beds at low flow is about 25 feet. Spawning
beds consist of materials mostly less than 6
inches in diameter.

Twelvemile Creek has a more stable discharge
than either Harris River or Indian Creek. During
spawning, average daily discharge usually varies
between 12 and 300 c.f.s. During autumn
storms, average daily discharge rarely exceeds
600 c.f.s. Intertidal spawning areas average
about 45 feet wide during low flow, and spawning
beds consist mostly of materials less than 4 inches
in diameter, and contain a high percentage of
sand and silt. About 5 miles are believed ac-
cessible to salmon, but the distance has not been
measured. Heaviest densities of spawning pink
salmon have been observed in the intertidal
zone. Chum salmon, less abundant here than
pink salmon, commonly spawn in the intertidal
zone, too.

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

501

Figure 4. — Locations of study streams (Harris River and Indian and Twelvemile Creeks) in the Kasaan Bay

region of Prince of Wales Island, Southeastern Alaska.

Field studies began in 1956 when FRI personnel
selected six spawning riflles ranging in area from
260 to 650 m.L' for sampling. Spawning riffles
were sampled in 1956, 1957, and 1958 to measure
mortality of eggs and larvae and the quality of
intragravel water (table 1).

The study areas were enlarged in 1958, when
FRI personnel selected five spawning areas

ranging in size from 3,400 to 1^,400 m.2 The
areas included major spawning grounds of pink
and chum salmon in Harris River and Indian
and Twelvemile Creeks and incorporated the six
spawning riffles previously sampled. The sam-
pling areas were selected to represent both inter-
tidal and upstream areas of the study streams
(table 1). Factors measured included density

U.S. FISH AND WILDLIFE SERVICE

Table 1. — Size and location of six spawning riffles sampled
in 1956, 1957, and 1958 and five spawning areas sampled
in 1958, 1959, and 1960

Study area and years sampled

1956, 1957, 1958

Rime A, Harris River

Riffle B, Indian Creek

Riffle C, Indian Creek

Riffle D, Twelvemile Creek.
Riffle E, Twelvemile Creek..
Riffle F, Twelvemile Creek.

1958, 1959, 1960

Intertidal Harris River

Upstream Harris River

Intertidal Indian Creek

Intertidal Twelvemile Creek..
Upstream Twelvemile Creek.

Tide level

Meters

3.4
4.0
5.2
3.7
4.3
4.9

3. 7-1. 3

3. 4-5. 2
3. 7-1. 9

Area

Meters

305
386
260
648
372
486

7,800
13, 400
3,400
5,580
6,130

and distribution of spawners, mortality of eggs
and larvae, quality of spawning beds, and quality
of intragravel water.

To insure random sampling, FRI personnel drew
maps of areas sampled to scale on cross-sectional
paper having 100 squares per square inch. The
scale selected made each square representative
of not more than a 0.4 m.2 area in the stream.
Co-ordinate axes were established for each map,
and sampling points were selected by the following
procedure. A pair of random numbers was
obtained from a random number table — one
number for the abscissa and the other number for
the ordinate. Distance of the selected square
from a reference point and an angle of the selected
square from a reference line were measured on the
map and recorded for use in the field. When a
sample was to be taken, the angle and distance
of the sample area were measured from the base
line and reference point.

MEASUREMENT OF ENVIRONMENTAL FACTORS

The Northern Forest Experiment Station, U.S.
Forest Service, operated a weather station at
Hollis, a logging community located within 3
miles of Harris River and Indian Creek spawning
areas and within 12 miles of Twelvemile Creek
spawning areas (see fig. 4). Forest Service per-
sonnel obtained continuous records of air tem-
perature and precipitation during the study.
Instruments installed and operated by the North-
ern Forest Experiment Station recorded water
level and temperature of each study stream.
Forest Service personnel also established discharge
rating curves for each stream. James (1956) gives

further information on hydrological studies made
by the Forest Service.

Physical quality of the spawning bed was
evaluated in each area where observations were
made on egg and larval mortality. Environ-
mental attributes measured included the dissolved
oxygen content of intragravel water and the size
composition and permeability of bottom materials.
McNeil (1962b) described the techniques used to
measure dissolved oxygen levels and McNeil and
Ahnell (1964) described the methods of measuring
size composition and indexing permeability of
bottom materials.

ESTIMATION OF SPAWNING DENSITY AND
POTENTIAL EGG DEPOSITION

Fisheries Research Institute (FRI) personnel
estimated the number of female pink and chum
salmon occupying study areas by means of daily
foot survey censuses when water conditions per-
mitted. Institute personnel also observed tagged
females daily to estimate average life on the
spawning ground (redd life) . Females were tagged
before they entered the spawning ground and FRI
workers calculated the total number spawning by
summing daily abundance and dividing by average

redd life; i.e.,

2]daily abundance in female
days

Number spawmng= average redd iife in days

A summation of daily abundance was obtained
by constructing an eye-fitted curve of the daily
counts of females and determining the area under
the curve in female days. In the determination
of average redd life, daily observations on tagged
females have been adjusted to account for the
periodicity of observations. Assuming that each
tagged female occupied the spawning bed one-half
day before being observed the first time and one-
half day beyond the date of the last observation,
I added 1 day to the duration each tagged female
was observed.

Two observers made most of the survey censuses;
periodic comparisons of their counts showed con-
sistently good agreement. Although it was not
feasible to determine bias in estimates, a recent
unpublished study conducted by the author at
Sashin Creek revealed good agreement between
the number of spawning female pink salmon esti-
mated by this method and the number counted
into the stream.

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

503

COLLECTION OF EGGS AND LARVAE

Eggs and larvae were collected with a hydraulic
sampler (McNeil, 1962a) from small enclosed
quadrat or circular areas (sampling units) of known
area. Area of sampling units varied from 0.2
to 0.9 m.2

Samples preserved in the field were examined
later to determine the number of live and dead
eggs and alevins collected. Eggs were preserved
in a clearing solution (Stockard's solution).

ESTIMATION OF MORTALITY

Data on egg and larval populations were
analyzed by three methods to obtain information
on temporal changes and spatial differences in
mortality levels. Although the methods have
been described (McNeil, 1962a), they will be
reviewed briefly here.

Ratio of Dead to Total Eggs and Larvae

Mortality has commonly been estimated from
ratios of dead to total e^<i's and larvae collected

in k samples;

.e..°

dead
live + dead

(3)

An estimate of mortality based on such ratios
underestimates true total mortality where the
number of eggs and larvae present in the spawning
bed at the time of sampling is less than the number
of eggs originally available for deposition. Des-
pite this limitation, estimates of Mr are very
helpful in establishing time of mortality where
mortality is caused by factors not associated with
the direct removal of eggs and larvae from the
spawning bed and are sometimes useful in setting
lower limits to total mortality.

Actual and Potential Abundance

Total mortality ( M ,) can be estimated from
statistics on potential egg deposition and abun-
dance of live eggs and larvae at the time of
sampling. In this study, estimates of M, were
calculated from the double inequality

1— gv<M«<l- -.,

(4)

In double inequality (4), the value a and a are
the upper and lower confidence limits respectively
of the estimated number of live eggs and larvae
per m.2 of spawning bed, and E' is the expected
number per m.2 Values for a and a were cal-
culated with the standard error of the mean
obtained from either arithmetic or log-transformed
counts of live eggs and larvae. Log-transformed
counts are used only if the efficiency of the esti-
mate of Mi is increased without introducing
significant bias.

Wliere the logarithmic transformation is used.
each observed count is transformed by the equa-
tion

6,=log10 (nt+P) (5)

In equation (5), 6, is the transformed variate
and iii is the number of live eggs and larvae
collected at the ith point. The term /3is a constant
which describes the degree of contagion in a nega-
tive binomial distribution. A value of /3 is calcu-
lated from the expected frequency of zero observa-
tions in a negative binomial distribution. The
method, described by Anscombe (1949) and Bliss
(1953), requires an iterative solution of the
equation

ilog!0 (l+j8SS) =

ogl0(p)

(6)

'The value M, estimates the population parameter M,. The circumflex
: di ill be used to Identify estimators ofother population parameters.

where k is the total number of observations, k' is
the number of zero observations, and n is the
sample arithmetic mean.

To set confidence limits to estimates of abun-
dance of eggs and larvae with log-transformed
data, the mean log values must be corrected so
that the arithmetic mean will result from the
antilog. A correction term is required because
the mean of log-transformed data is geometric
rather than arithmetic (Ricker, 195S, ch. 11).
Jones (1956) developed the correction term and
described the method used here to calculate
confidence limits with log-transformed counts.
The equation used to obtain an arithmetic mean
(n) from the log-transformed counts is

n=antilog (b+1.1518sl)-p, (")

where b is the logarithmic mean value and s]
is the sample variance of the log-transformed
counts. The term 13 is subtracted to correct for
its addition to the counts before making the
transformation in equation (5).

504

D.S. FISH AND WILDLIFE SERVICE

Provided the estimates a, a, and E' are un-
biased, double inequality (4) gives an unbiased
estimate of the total mortality fraction from the
time of spawning to the tune of sampling.
Absence from the spawning bed of dead eggs
and larvae does not introduce bias to estimates
of Mi as it does to estimates of MT based on ratios
of dead to total eggs and larvae present.

Potential egg deposition (E) is calculated by
multiplying the estimated number of female
salmon spawning within each area by average
fecundity. The value E' is obtained by multi-
plying E by a factor correcting for the fraction
of eggs and larvae present within the streambed
actually collected. In the present study, the
relationship

(8)

E'=roE

is used. Methods used to obtain the correction
9

term.

are described elsewhere (McNeil'

1962 a).

More recent studies provide evidence that

estimates of M, obtained with a hydraulic sampler

are fairly representative of the true total mortality

fraction. I used a hydraulic sampler to estimate

total mortality of 1961 and 196.3 brood year

preemergent pink and chum salmon fry in Sash in

Creek, where total fresh-water mortality also

was calculated from weir counts of adults entering

and fry leaving the stream. In Sashin Creek,

93
it was assumed that E' = jt-^ E for purposes of

setting confidence limits to Mt. Based on samples
of preemergent fry obtained with a hydraulic

Table 2. — Total mortality of Sashin Creek pink and chum
salmon estimated by sampling preemergent fry with hy-
draulic sampler and by counting migrating fry at weir

Mortality estimated
by sampling pre-
emergent fry

Mortality
estimated

Species and brood year '

Mean

90- percent

confidence

limits of the

mean

by counting
migrating fry

Pink salmon
1961 .

0.777
.800

.928
.997

±0. 041
±.052

±.056
±.040

0.790

1963- .

.804

Chum salmon

lyi'd

!I17

1963

.995

1 Mortality of the 1962 brood year was not estimated by sampling pre-
emergent fry because populations were very small. Only 4 pink and 42
chum salmon females entered Sashin Creek to spawn in 1962.

sampler, confidence limits of M, bracketed the
total mortality fraction calculated for each species
and brood year from weir counts. In each instance,
mean estimated mortality from sampling pre-
emergent fry and from counting migrant fry
differed by less than 2 percent. The results are
summarized in table 2. In vSashin Creek, po-
tential egg deposition was determined by counting
adults entering the stream. In Harris River
and Indian and Twelvemile Creeks, the methods
of estimating potential egg deposition were not
as precise, and it is doubtful if estimates of Mt
were completely unbiased.

Presence or Absence of Eggs and Larvae

Estimates of the population parameters MT and
Mt sometimes fail to differ significantly when other
evidence suggests high mortality. A chi-square
test helped demonstrate significant mortality in
certain of these cases and often proved to be a more
sensitive test for detecting time of mortality than
the mortality estimates Mt and MT-

The chi-square test is based on the premise that
the proportion of points within a spawning bed
occupied by live eggs and larvae varies with total
mortality. If no change in mortality occurs, the
following conditions will be satisfied: (1) There
will be no decrease in the expected fraction of
points populated by eggs or larvae (live plus dead) ;
(2) there will be no decrease in the expected frac-
tion of points populated by live eggs and larvae ;
and (3) there will be no increase in the expected
fraction of points populated by dead eggs or larvae.

In this study, each point sampled was classified
according to the number of eggs and larvae present,
with points containing less than 35 eggs and larvae
per m.2 (k0) being classified together. The classes
used were (1) less than 35 live plus dead eggs and
larvae per m.2, (2) less than 35 live eggs and larvae
per m.2, and (3) less than 35 dead eggs and larvae
per m.L.

Principal purpose of the classification scheme
was to classify jointly all points containing few
eggs and larvae and those containing none. The
selection of less than 35 per m.2 for joint classifi-
cation was arbitrary, however.

I tested each class independently with chi-
square (see Snedecor, 1956), and set confidence
limits to the number of points estimated to con-
tain fewer than 35 eggs and larvae per m.2 from the
normal approximation of the binomial distribution.

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

505

The 90-percent confidence limits of k0 (k0 and k0)
are obtained from the expression

(ito, kB)=kp0±l.U5[kp0 (l-po)]m

(9)

where k is the number of points sampled and p
is the fraction of points estimated to contain
fewer than 35 eggs and larvae per m.2

OBSERVATIONS ON ENVIRONMENT AND
MORTALITY

Although numerous workers have postulated
factors causing mortality of eggs and larvae, few
have presented quantitative estimates of mortality
satisfying three essential criteria: (1) Estimates
free of bias, (2) estimates representative of natural
populations, and (3) estimates related directly to
causative factors. It is not surprising that these
criteria have not been met entirely in field studies,
for there are many difficult problems requiring
solution. In the present study, an effort was made
to reduce (or at least recognize) bias in mortality
estimates. Furthermore, because of the randomi-
zation techniques used, the samples were thought
to be representative of the populations studied.
However, the difficulties in associating observed
mortality levels with their causative factors are
formidable even with the first two criteria being
satisfied in part. The problem of relating observed
mortality levels to causative factors is complicated
in most instances because of interactions among
environmental factors.

I attempted to account for interactions by classi-
fying environmental factors causing mortality into
generally inclusive groupings: (1) Oxygen supply
and related factors, (2) stability of the spawning
bed, and (3) freezing of intragravel water. I did
not consider one inclusive grouping — pathogenic
agents.

OXYGEN SUPPLY AND MORTALITY

Environmental requirements of salmon eggs and
larvae were briefly reviewed in an earlier section.
My purpose here will be (1) to describe the physical
characteristics of spawning beds where observa-
tions on mortality were made, and (2) to describe
the relation between environmental quality (as
related to oxygen supply) and the observed
mortality levels.

Dissolved Oxygen Content of Intragravel Water

The dissolved oxygen content of intragravel
water was consistently lower at the beginning than
at the end of the spawning period in all study
streams. There also were observed spatial differ-
ences in mean dissolved oxygen levels among and
within the study streams.

In late August, at the beginning of spawning,
oxygen levels appeared to be lowest in the intertidal
Harris River and the upstream Twelvemile Creek
spawning areas and highest in the upstream Harris
River and the intertidal Indian Creek and Twelve-
mile Creek spawning areas. Near the end of
spawning, in late September, differences in mean
oxygen levels were no longer significant among
the spawning areas sampled. The data are sum-
marized in table 3, and mean values obtained in
1959 are shown in figure 5 to illustrate the kind of
relation observed.

Differences among years in mean dissolved
oxygen levels were considerably greater than
differences among streams. Summer 1957 was
of particular interest in this regard because
unusually low levels of dissolved oxygen were
observed. Average values of all dissolved oxygen
determinations made in the study streams near
the beginning of spawning over the period 1956

<s>

o
o

liJ

>-
X

o
to

z
<

LEGEND

O INTERTIDAL HARRIS RIVER
• UPSTREAM HARRIS RIVER
a INTERTIDAL INDIAN CREEK
o INTERTIDAL TWELVEMILE CREEK
■ UPSTREAM TWELVEMILE CREEK

SEPT I

SEPT. 20
1959

Figure 5. — Mean dissolved oxygen content of intragravel
water in the study streams over the period of spawning
in 1959.

.IOC

U.S. FISH AND WILDLIFE SERVICE

Table 3. — Ninty-five-percent confidence interval estimates of

mean dissolved oxygen content of inlragravel water in study

streams

(Water samples were collected 7 to 10 inches beneath the stream bed surface.
All values are given as mg./l.]

Date

Harris River

Indian

Creek

Intertidal

Twelvemile Creek

Intertidal

Upstream

Intertidal

Upstream

19SS

6. 3<,i<7. 4
8.3<(i<9. 5

6.8<k<8.3
6.5<m<8.5

4.8<<i<6. 1

8.0<m<9.6

1959

Aug. 28
Sept. 17

5. KM<7.0
5.6<ji<9. 1

6.4<ju<8. 1
6.0<m<8.4

7.5<,i<8.9
7. 1<m<9. 3
7. 4<^<8. 4

5. 3</*<6. 9

6. 7<m<8. 4

Sept. 27
I960

S. 1<m<9.3

6.8<»i<8.0

5. 6<>.<6. 7

Aug. 25
Sept. 14

5.4<M<6. 6
7. K/i<9.0

5.8<m<7.0

6.3<^<7.8
7. 6<>j<8.9

7. 5<^<9. 0

5.4<f.<7.2

through 1960 are shown in figure 6. Oxygen
levels were severely depressed in 1957, and high
mortality of 1957 brood year eggs occurred. The
relation between mortality and oxygen levels will
be discussed later.

COMPOSITION OF BOTTOM MATERIALS

There were marked differences in size composi-
tion of bottom materials among the study streams.
The bed of Indian Creek contained greater quan-
tities of coarse materials and smaller quantities of

O ^

£ 6-

z <

Lul §

£^

x w

°£

UJ (5 ? _
>< Cr

Q 0

fine materials than the beds of either Harris River
or Twelvemile Creek. The bed of Twelvemile
Creek contained considerably more silt than the
beds of Indian Creek or Harris River. Table 4
lists the average size composition (by volume) of
bottom materials in each of the study streams.

The volume of fine materials in salmon spawn-
ing beds is inversely related to the permeability of
bottom materials (McNeil and Ahnell, 1964).
Figure 7 shows the observed relation between the
percentage of bottom materials by volume passing
through an 0.833-mm. sieve and the coefficient of
permeability.

The observed mean percentages of solids passing-
through an 0.833-mm. sieve are listed below for the
study streams in order of decreasing permeability :

Percent

1 . Intertidal Indian Creek 9

2. Upstream Harris River 14

3. Intertidal Harris River 1"

4. Intertidal Twelvemile Creek 18

.5. Upstream Twelvemile Creek 19

McNeil and Ahnell (1964) found that the finest
fractions contained the highest percentages of
organic detritus. It will be assumed, therefore,

600

500

o
>-

b 400 -

LlJ

o
u.

O
O

300

200

100

1956 1957 1958 1959 I960

5 10 15 20 25

PERCENTAGE OF BOTTOM SAMPLE BY VOLUME
PASSING THROUGH 0.883-MM. SIEVE

Figure 6. — Approximate mean dissolved oxygen content
of intragravel water in the three study streams (Harris
River, Indian Creek, and Twelvemile Creek) near the
beginning of the spawning period (1956-60).

Figure 7. — Relation observed between coefficient of per-
meability and the fraction by volume of a bottom sam-
ple passing through an 0.833-mm. sieve (from McNeil
and Ahnell, 1964). Curve fitted by eye.

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

507

Table 4. — Average size composition of bottom materials in the study streams '
[All rocks larger than 105 mm. diameter have been excluded]

Spawning area

Harris River (intertidal)

Harris River (upstream)

Indian Creek (intertidal)

Twelvemile Creek (intertidal).
Twelvemile Creek (upstream) _

Mean percent of total volume of solids retained by sieves with opening (in mm.) of— »

26.26 13.33 6.88

25.1
24.0
35.2
21.2
19.7

14.6
16.2
15.3
15.1
13.9

13.2
14.1
12.9
13.9
13.0

11.0
11.8
11.3
12.5
12.9

1.65 0.833 0.417 0.208 0.104

7.9
8.4
7.3
8.8
9.6

11.5
11.8
8.6
10.7
11.6

10.5
9.2
4.9
8.4
9.5

2.7
2.4
1.3
2.5
3.6

0.4
.4
.4
.9

1.2

Percent of
total vol-
ume of
solids
settling
from
suspension

3.1
1.9

2.7
5.9
5.0

1 For a description of methods of collecting and classifying samples, the reader is referred to McNeil and Ahnell (1964).
'■ Data are taken from table 2 of McNeil and Ahnell (1964).

that the percentage of fine materials obtained from
the settling funnel used in the analysis of bottom
samples (McNeil and Ahnell, 1964) provides an
index of the relative amounts of extraneous
organic matter in spawning beds. Percentages
of fine materials passing through a 0.104-mm.
sieve, observed in the total volume of bottom
materials collected from the areas sampled, are
listed below in order of increasing values:

Percent

1 . Upstream Harris River 1.0

2. Intertidal Indian Creek 2.7

3. Intertidal Harris River 3.1

4. Upstream Twelvemile Creek 5.0

5. Intertidal Twelvemile Creek 5.9

The rate of interchange between stream and
intragravel water is believed to be related to
gradient and roughness of the stream bottom.
Steep-gradient areas have a greater potential for
changes in curvature of the stream bottom than
shallow-gradient areas, and coarse materials give
greater roughness to the stream bottom than fine
materials. To index relative roughness, the study
areas are listed below in order of decreasing
amounts of solids retained by the largest sieve
used in this study (26.26-mm.).

Percent

1. Intertidal Indian Creek 35

2. Intertidal Harris River 25

3. Upstream Harris River 24

4. Intertidal Twelvemile Creek 21

5. Upstream Twelvemile Creek 20

In addition to having the largest fraction of
coarse gravel, Indian Creek also had the steepest
gradient (0.7 percent as opposed to 0.2 to 0.4
percent for the other areas). The evidence
suggests that the interchange potential of Indian
Creek is greater than Harris River or Twelvemile
Creek.

Spawning Density

According to the evidence just presented,
environmental conditions related to oxygen supply
and survival of eggs and larvae would appear to be
most favorable in intertidal Indian Creek and least
favorable in upstream Twelvemile Creek. The
remaining three areas did not appear to vary
significantly with regard to the environmental
factors evaluated. Observed distributions of
spawning female pink and chum salmon appeared
to be related to the physical characteristics of the
spawning beds studied.

For the years 1958, 1959, and 1960 intertidal
Indian Creek had the highest average density of
spawners, and upstream Harris River and Twelve-
mile Creek had the lowest. In order of decreasing
average density, the density of spawning females
in the sampling areas were estimated to be:

1. Intertidal Indian Creek.

2. Intertidal Harris River.

3. Intertidal Twelvemile Creek

4. Upstream Harris River.

5. Upstream Twelvemile Creek

mean = 35 females per
100 m.2 (range 13 to
46 females per 100
m.2)

mean =29 females per
100 m.2 (range 13 to
48 females per 1Q0
m.2)

mean= 17 females per
100 m.2 (range 11 to
25 females per 1 00
m.2)

mean = 4 females per
100 m.2 (range 2 to
0 females per 100
m.2)

mean =4 females per
100 m.2 (range 1 to
10 females per 100
m.2)

508

U.S. FISH AND WILDLIFE SERVICF.

Time and Magnitude of Mortality

The amount of dissolved oxygen required by
salmon eggs and larvae for normal metabolism
approaches a maximum just before hatching (see
fig. 2). After hatching, levels of dissolved oxygen
limiting metabolism are greatly reduced, and
oxygen requirements are least likely to be satisfied
before hatching.

Pink and chum salmon eggs begin to hatch in
the study streams in November, and most hatch
before mid-December. Figure 8 shows the per-
centages of live eggs and larvae collected from
intertidal Harris River and Indian Creek that had
hatched before the date of sampling. Twelvemile
Creek is thought to lag 1 or 2 weeks behind
Harris River and Indian Creek with regard to
time of hatching, because the peak of spawning-
occurs about 1 week later.

After the spawning period, it is convenient to
consider two periods during which mortality
occurs — prehatching (autumn) and posthatching
(winter). The dissolved oxygen supply and re-
lated factors are thought to exert their greatest
influence on mortality before hatching, so the

6.J

- o

HARRIS RIVER

'58

•

INDIAN CREEK

'60

'58 so

• •

'58
'59. %9

'56

•

Id
o

01
UJ
Q_

1-
<

c/>
o
o

NOV. I DEC. I JAN. I

DATE OF COLLECTION

Figure 8. — Percentage of live eggs and larvae in collec-
tions from intertidal Harris River and Indian Creek
hatching before the date of sampling. (Brood years are
indicated by numerals.)

discussions here will be limited primarily to
mortality of eggs.

In this study, estimates of three population
parameters thought to provide evidence of the
effect of oxygen supply and related factors on egg
mortality were used: (1) Total mortality fraction
(M,), (2) mortality fraction from ratios of dead
eggs in samples (MT), and (3) fraction of points
containing fewer than 35 dead eggs per m.2 (p0)-

An estimate of M, includes mortality from all
causes, and this estimate includes eggs removed
from the spawning bed. Such removal can ob-
scure mortality from causes where there is no
direct removal of eggs; therefore, the estimated

total mortality (M ,) was often of limited value
in measuring egg mortality from oxygen supply
and related factors. Furthermore, estimates of
M, were highly inefficient, and the resulting con-
fidence limits were often broad.

The other two estimates (M, and pn) also had
limitations imposed by the disappearance of eggs
from the spawning bed. Disappearance from
gravel shift alone would have little effect on
validity of estimates of ratios of dead to total eggs

present in the streambed (Mr), provided live and
dead eggs disappear in numbers proportional to
their abundance. On the other hand, losses from
decomposition and scavenging affect only dead
and dying eggs and would cause mortality to be

underestimated by Mr.

Use of the number of points where eggs were
present or absent to index occurrence of mortality
also would be affected by disappearance because
evidence of mortality from factors not related to
the direct removal of dead eggs would have been
destroyed. Major losses due to gravel shift would
tend to invalidate the use of p0 to detect significant
mortality possibly caused by oxygen supply and
related factors.

With these possible limitations in mind, the
estimates of M,, MT, and p0 are used to evaluate
prehatching mortality of the 1956-60 brood years
in the three study streams. Each brood year will
be considered separately.

1956 Brood Year

Sampling was confined to spawning riffles A
(Harris River), B and C (Indian Creek), and D
and E (Twelvemile Creek). Workers sampled the
riffles in late November 1956 and in late February

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

509

Table 5. — Estimated mortality of 1956 brood year pink and chum salmon egqs and larvae based on ratios of dead to total

specimens collected

Fraction of dead eggs
in late November (MO

Fraction of dead eggs
and larvae in late

February (A/,)

Estimated fractions of eggs
and larvae dying-

Stream >

Mean

90-percent

confidence

limits of

the mean

Mean

90-percent

confidence

limits of

the mean

Early

Shortly

before

hatching

After
hatching

0.27
.10
.27

±0.06
±.04
±.06

0.50
.75
.41

±0.14
±.10
±.10

0.27
.10
.27

0.14
.54
.12

0.09

.11

.02

i All samples were collected from intertidal riffles.

1957. Since spawning density was not estimated
in 1956, no estimates of Mt are given. Also,
because of small sample size, it is not possible to
give meaningful estimates of p0. Thus, for the

1956 brood year, only estimates of MT are given to
indicate time and magnitude of mortality (table 5).

In autumn 1956, egg mortality appeared to be
highest after embryos had eyed. The February
sample included three general categories of dead
specimens: (1) Embryos dying early (as evidenced
by the opacity and advanced decomposition of the
eggs), (2) embryos dying just before hatching (as
evidenced by development of body structures) , and
(3) larvae dying after hatching. Table 5 gives
estimates of the fractions of total deaths occurring
early, shortly before hatching, and after hatching.

Two features of these data stand out. First,
early egg mortality was lowest in intertidal Indian

A A

Creek (Mr=0.10 versus Mr=0.27 in intertidal
Harris River and Twelvemile Creek). Second,
this relation had reversed by late February. Other
evidence, which will be considered later, strongly
suggests that freezing was the major cause of
mortality of the 1956 brood shortly before and
after hatching.

With regard to early egg mortality possibly
associated with oxygen supply and related factors,
evidence from 1956 brood year embryos does not
contradict the possibility that intertidal Indian
Creek provides a more suitable environment than
either intertidal Harris River or Twelvemile
Creek.

1957 Brood Year

Estimated mortality of the 1957 brood year
provided the most striking evidence obtained in
the course of these studies on relation between
oxygen supply and egg mortality. As shown in
figure 6, mean dissolved oxygen levels during the

spawning period in 1957 were less than 50 percent
of other years. These low levels of dissolved
oxygen occurred during a prolonged period of
low precipitation and discharge. For example,
between August 10 and September 25, discharge
of Indian Creek exceeded 20 c.f.s. only 30 percent
of the time. Also, over this period very low
discharge (4 to 10 c.f.s.) prevailed for 2 weeks
during and after spawning. Furthermore, clear
skies prevailing over the latter half of September
were thought to have contributed to an unusually
prolific growth of periphyton observed on the
surface of streambeds at the time.

The escapement of adults was the lowest ob-
served during these studies. The density of adult
female pink and chum salmon spawning in inter-
tidal areas of the study streams was five or less
per 100 m.2. The period of spawning lasted only
from about September 7-17, the briefest period
observed.

There was good evidence that egg mortality
was high after spawning in 1957. Eggs were
collected from riffles B and C in intertidal Indian
Creek and riffles E and F in intertidal Twelvemile
Creek during early November 1957 and late March
1958 and from intertidal Harris River in early
April 1958.

Because differences in estimated values of Mr
were not significant among the study riffles
sampled, samples collected from intertidal Indian
and Twelvemile Creeks were pooled by date to
give the following single estimates of M, and their
90-percent confidence limits:

November Mr=0.69±0.1!t

March M,= 0.57±0.24
Difference between the two estimates i> not sig-

.-,10

U.S. FISH AND WILDLIFE SERVICE

nificant. The data indicate that mortality was
high before hatching and low after hatching.

Most dead eggs collected in November already
had decayed considerably and were classified as
fragments, suggesting that mortality occurred
shortly after spawning. This finding would not
be unexpected because dissolved oxygen levels
were unusually low during spawning. Further-
more, there was evidence of high biochemical
oxygen demand continuing well into autumn 1957.
Although oxygen levels had increased significantly
between August and November 1957, they were
still lower in November 1957 than in August 1958,
even though water temperatures were about
6° C. cooler in November 1957 than in August
1958 (McNeil, 1962b).

The high percentage of fragments among dead
specimens collected from intertidal Indian and
Twelvemile Creeks in November 1957 remained
virtually unchanged through March 1958. The
values were:

Indian Creek

Riffle B: 92 percent in November and 96

percent in March.
Riffle C: 70 percent in November and 70

percent in March.

Twelvemile Creek

Riffle E: 66 percent in November and 76
percent in March.

Riffle F: 97 percent in November and 95
percent in March.
This was nearly conclusive evidence that estimates
of MT obtained from egg fragments alone would
be little changed over late autumn and winter,
and estimates of Mr based on presence of egg
fragments and made in early spring 1958 would
give essentially the same result as estimates made
the previous autumn.

Intertidal Harris River was sampled about
April 1, 1958, when egg fragments or live larvae
were collected at 34 points. Only egg fragments
were found at 31 of the 34 points, giving minimal
estimates of

M,>Mr=31/34=0.91

The available evidence suggested that condi-
tions in 1957 were unfavorable for egg survival,
and exceptionally high egg mortality occurred in
all study streams. This high mortality was

associated with unusually low levels of dissolved
oxygen in intragravel water and low density of
spawners. Unexpectedly low levels of dissolved
oxygen prevailed into November 1957, suggesting
that the biochemical oxygen demand was unusually
high. There is a possibility that the density of
females spawning (five or less per 100 m.2) was
too low to remove accumulated organic detritus
from spawning beds in quantities sufficient to
reduce materially the biochemical oxygen demand
(Ricker, 1962; McNeil and Ahnell, 1964).

1958 Brood Year

Adult escapements were moderately low in
1958, though considerably higher than in 1957.
Spawning densities ranged from 13 females per
100 m.2 in intertidal Harris River and Indian
Creek to 1 and 2 females per 100 m.2 in upstream
Twelvemile Creek and Harris River, respectively.
Density of spawning females in intertidal Twelve-
mile Creek was 11 per 100 m.2

Hydrological conditions during spawning fa-
vored a higher egg survival than in 1957. Indian
Creek maintained discharges of 10 c.f.s. or more
over the spawning period as opposed to a minimum
discharge of 4 c.f.s. during spawning in 1957,
when high early egg mortality occurred.

Observations on mortality were made in inter-
tidal Harris River, Indian Creek, and Twelvemile
Creek. Spawning densities in upstream Harris
River and Twelvemile Creek were too light to
warrant investigations in these areas. Table 6
summarizes the results of the mortality estimates.

For purposes of the present discussions, inter-
tidal Twelvemile Creek can be dismissed because

of extreme high early mortality (M(=0.97 by
late November) apparently caused by scouring
during floods, which physically removed eggs
from the spawning bed.6 As a consequence,
there were insufficient numbers of eggs remaining
to relate observations on mortality to observa-
tions on factors affecting oxygen supply. Workers
resampled the area in December primarily to
check the results of the November sampling.
The numbers of eggs collected approached
expectation in intertidal Harris River and Indian
Creek. Indian Creek was sampled on one

s Potential egg deposition in intertidal Twelvemile Creek during September
1958 was estimated to be 175 per m.2 By late November, mean density of
live plus dead eggs was estimated to be only four per m.3; by late December
only one per m.2

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

511

Table 6. — Estimates of Mt, Mr, and p0 used to evaluate time and magnitude of mortality of 1958 brood-year eggs

Spawning area and date

Mean

90- percent

confidence

limits of the

mean

Mean

90-percent

confidence

limits of the

mean

Mean

90- percent

confidence

limits of the

mean

Intertidal Harris River:

Sept. 18 .-

0.26
.51
.84

.97
.99

' ±0.25

l ±.35

±.21

l±.39

±.04
±01

0.01
.16
.66

.13

±0.01
±.23
±.38

±.13

1.00
.96
.82

.90

1.00
1.00

Nov. 15

±0.06

Dec. 20

±.12

Intertidal Indian Greek:

Nov. 15- .

±.07

Intertidal Twelve mile Creek:
Nov. 30 ..

Dec. 28

1 These estimates of M were obtained with log-transformed data.

occasion only (mid-November), and comparisons
between the two areas will be limited to the
mid-November samples.

The expected number of eggs based on potential
deposition was 201 per m.2 in both intertidal
Harris River and Indian Creek. In mid-Xovem-
ber the difference between mean estimates of

MT (Mr=0.16 in intertidal Harris River, and

Mr=0.13 in intertidal Indian Creek) was not
statistically significant. Furthermore, a com-
parison of values of p0 in November gave a chi-
square value of 0.46 (1 d.f.), indicating no sig-
nificant difference in the frequency of occurrence of
dead eggs in intertidal Harris River and Indian
Creek. Hence, for the 1958 brood year, there was
no conclusive evidence of higher egg mortality
in intertidal Harris River than in intertidal
Indian Creek. It is noteworthy, perhaps, that in

intertidal Harris River M, increased significantly
between mid-November and mid-December. It
wjiot known if a similar increase occurred in
intertidal Indian Creek.

1959 Brood Year

Density of spawners was highly variable among
and within the study streams in 1959. Estimated
densities of females spawning were:

Intertidal Harris River 25 females per 100 in.2

Upstream Harris River 6 females per 100 m.2

Intertidal Indian Creek 46 females per 100 m.2

Intertidal Twelvemile Creek.. 15 females per 100 m.2
Upstream Twelvemile Creek.. 1 female per 100 m.-'

Because of the very low density of spawning
adults, mortality was not studied in upstream
Twelvemile Creek, but observations on mortality
were made in upstream Harris River. High
stream discharge occurred during spawning, pro-
viding more favorable conditions for egg survival
during spawning than in 1957. Results of studies
on mortality of the 1959 brood year are sum-
marized in table 7.

As observed in 1958, mortality in intertidal
Twelvemile Creek was very high initially and
apparently was associated again with the direct
removal of eggs from the spawning bed. Since
estimates from upstream Harris River indicated

Table 7. — Estimates of Mt, Mr, and po used to evaluate time and magnitude of mortality of 1959 brood year eggs

po '

Spawning area and date

Mean

90-percent

confidence

limits of

the mean

Mean

90-percent

confidence

limits of

the mean

Mean

90-percent
confidence

limits of
the mean

Intertidal Harris River:

Oct. 6.. _

il. .'7
.35

.73

.82
.27

.95

±0. '.'1
-' ±.21

±.23

±.18
±.■29

±.07

0.08
.11

. 17

.08
,02

±0.06
±.09

±.33

±.07
±.01

0.97
.89

.99

.96
.90

1.00

±0.03

Oct. 20

±.07

Upstream Harris River:

Nov. 4 _

±.01

Intertidal Indian Creek:

Oct. 10

±.04

Nov. 10

±.08

[ntertidal Twelve-mile Creek:
Oct. 27

e traction of points containing fewer than 35 dead eggs per square meter.
•' This estimate of M, was obtained from log-transformed data.

512

U.S. FISH AND WILDLIFE SERVICE

much the same thing, these areas proved to be of
little value in evaluating relations between
mortality and oxygen supply.

Differences in mortality level between intertidal
Harris River and Indian Creek could not be
demonstrated with estimates of MT and Mt.
However, estimates of p0 made in mid-October
showed that samples containing 35 or more dead
eggs per m.2 occurred with almost equal frequency
in intertidal Harris River and Indian Creek
despite much lower spawning density in intertidal
Harris River (about 53 percent of intertidal
Indian Creek). This evidence suggested that egg
mortality was higher in intertidal Harris River
than in intertidal Indian Creek.

I960 Brood Year

Egg mortality was studied in intertidal Twelve-
mile Creek, Harris River, and Indian Creek
(tableS).

High early mortality from causes associated
with the direct removal of affected specimens from
the spawning bed occurred in intertidal Twelve-
mile Creek for the third year. In 1960, however,
most of this high mortality occurred during spawn-

ing (M t=0.71 in late September).7 Since mor-
tality from causes associated with spawning (e.g.,
redd superimposition) is beyond the scope of this
paper, these causes will not be considered further
here. By late November there was evidence of
increased egg mortality in intertidal Twelvemile
Creek, but this mortality was relatively low.

The density of females spawning in intertidal
Harris River and Indian Creek was relatively high
and nearly equal. Late in September at the con-

7 This same phenomenon was also observed in 1961 (unpublished data,
FRI, University of Washington, Seattle).

elusion of spawning, estimates of MT and p0 were
very nearly the same for these two areas. At
hatching, however, 35 or more dead eggs per m.2
were found at 26 percent of the points sampled in
intertidal Harris River and at only 10 percent of
the points sampled in intertidal Indian Creek.
Estimates of MT also indicated that mortality of
eggs remaining in the streambed was higher in
intertidal Harris River than in intertidal Indian
Creek.

STABILITY OF THE SPAWNING BED AND
MORTALITY

Two factors causing gravel to shift in spawning
beds are flooding and females digging redds. The
importance of redd superimposition as a factor
limiting production of salmon fry is beyond the
scope of this paper and will not be considered.
My discussions will be limited to the influence of
flooding and debris movement on egg and larval
mortality.

Mortality caused by gravel shift would make
itself evident by complete disappearance of eggs
and larvae from spawning beds. Changes in
abundance and distribution of eggs and larvae
will be examined to obtain evidence of mortality
caused by gravel movement. Three population
parameters will be considered in evaluating the
stability of spawning beds: (1) Total mortality
(Mt), (2) mean abundance of eggs and larvae per
m.2 (live plus dead)(P), (3) fraction of points
containing fewer than 35 live plus dead eggs per
m.2 {&').

High discharge occurs most frequently in South-
eastern Alaska streams during October, Novem-
ber, and December. Autumn storms are often
accompanied by heavy rain which sometimes

Table 8. — Estimates of Mt, Mr, and p(1 used to evaluate time and magnitude of mortality of I960 brood year eg

Spawning area and date

Intertidal Harris River:

Sept. 28

Dec. 2

Intertidal Indian Creek:

Sept. 22 _.

Nov. 22

Intertidal Twelve-mile Creek

Sept. 30

Nov. 30

.44
.50

.71

.75

90-percent

confidence

limits of

the mean

±0.18
±.09

±.20
±.22

0.03
.18

90-percent

confidence

limits of

the mean

±0.01
±.07

Pal

0.92
.74

90-percent

confidence

limits of

the mean

±0.05
±.07

±.05
±.06

±.02
±.03

1 Po is the fraction of points containing less than 35 dead eggs per square meter.
- This estimate of M, was obtained with log-transformed data.

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON
774-711 O— 66 15

513

Table 9. — Dates on which, rain1 at Hollis, Alaska, exceeded
4.0 inches in 72 hours, 1956-60

Dates precipitation exceeded 4.0 inches in a 72-hour period

Amount

1956

Inches

Nov. 21-23

1957

4.08

Oct. 19-21

1958

6.79

Oct. 28-31 -

5.08

Nov. 7-9

4.14

Nov. 5-7

1959

5 32

Dec. 5-7

7.02

Oct. 9-11...

I960

4.31

Oct. 20-22

4.08

1 Data provided by Northern Forest Experiment Station, U.S. Forest
Service, Juneau, Alaska.

continues over several days. To index periods of
heavy precipitation, dates on which total precipi-
tation exceeded 4 inches in 72 hours at Hollis
(fig. 4) are given in table 9. Stream discharge
records revealed that unusually high discharges
accompanied rainfall of this high intensity. The
analysis showed that rain was most intense in
1958 and 1959 and least intense in 1956 and 1957.
Although a comprehensive evaluation of mor-
tality of 1956 and 1957 brood year eggs and larvae
was not feasible because of limited sampling,
estimates of Mr obtained for these brood years
(and discussed previously) gave no indication of
losses occurring from spawning beds. Observa-

tions on subsequent brood years (1958 and 1959
particularly) have shown, however, that gravel
movement during high discharge is an important
cause of mortality in the study streams.

1958 Brood Year

Rainfall exceeded 4.0 inches in 72 hours three
times between October 19 and November 9, 1958
(table 9). Samples of eggs were collected before
and after the storms in intertidal Harris River
and after the storms in intertidal Indian and
Twelvemile Creeks (table 10).

The number of eggs (P) estimated to be present
in intertidal Harris River near the end of spawning
agreed with the expected number (£') obtained
from the estimated density of females spawning

(P=189 and £" = 201 per m.2). After the three
periods of heavy rainfall, the abundance of eggs
had decreased significantly, and the fraction of
points containing fewer than 35 eggs per m.2 had
increased significantly (X2=b.b, 1 d.f.). This was
good evidence that a significant mortality at-
tributable to gravel movement had occurred.

In Indian Creek, the number of eggs estimated
to be present in November after the storms agreed

with the expected number (P=222 and £" = 202
eggs per m.2) ; hence, there was no evidence of
mortality from gravel movement in intertidal
Indian Creek.

The number of eggs estimated in intertidal
Twelvemile Creek after heavy rainfall was con-

Table 10. — Estimates of the population parameters E', P, p'0, and Mt used to evaluate mortality of 1958 brood year eggs

possibly caused by movement of bed materials

Spawning area and date of observation

Number of

occasions

precipitation

was more

than 4

inches in 72

hours

Number of dead plus
live eggs per m.2

(E' and P)

Fraction of points

containing fewer

than 35 eggs per m.2

(P'o)

Total mortalitj l Mi)

Mean

90- percent

confidence

limits of

the mean

Mean

90- percent

confidence

limits of

the mean

Mean

90- percent

confidence

limits of

the mean

Intertidal Harris River:

i 189
i 104
3 201
'223
3 174
4

J ±101

= ±74

0.71
.83

±0.11
±.09

0.26
.51

= ±0.25

-'±.35

Intertidal Indian Creek

2 ±84

Intertidal Twelvemile Creek:

±6

E i [mated number of live plus dead specimens in the spawning bed (P).
- These limits were set with log-transformed data.
' Expected number of specimens based on potential epR deposition (/?')-

;»i4

U.S. FISH AND WILDLIFE SERVICE

siderably less than the expected number. It was 7 for the

same dates. '

rhe area sampled on

thought initially that high discharge caused November 16 included 75 percent of the intertidal

mortality; however, samples were not collected Harris River spawning area described in table 1.

before heavy precipitation in 195S, and it will be Trees felled by loggers into upstream Harris

shown subsequently that high mortality of 1960 River and transported through intertidal Harris

brood year eggs in Twelvemile Creek occurred in River on the crests of two mid-October freshets

association with spawning before the storms.

appeared to cause little or no mortality. Nine-

1959 Brood Year

teen spruce and hemlock trees, some more than 3

feet in diameter at the base of the trunk and more

Heavy rainfall occurred in early November an

& than 100 feet long, and several large alder trees

December 1959. The evidence indicated that were known to have floated through the intertidal

mortality occurred in association with heavy rain „ ,. r -£ , . ,A, . ,,
in all areas sampled (table 11) ZOne' Estimates of P' Po, and M, were nearly the
r™ . ,. , V tt • -n- l- same for samples collected before (October 6) and
Ihe intertidal Harris River sampling program ., ._. x , ... ,, . n

j-c j i- i_xi • ,^r« * i I i atter (October 20) the presence ot floating trees,
was modified slightly in 1959 to evaluate egg and „, . , , .. ° .
, , , . , , .,, , . ., ,. there was evidence that mortality occurring in
larval losses associated with heavy precipitation. . ... . _ . „. , ~ , , .

-n ixi at i. fn j- j intertidal Harris River between October 20 and
Because a sample taken .November 16 did not in- ,T , , , ,
, , ,, , , ., , . November 16 was caused by gravel movements
elude the entire area sampled on other dates, , . , . „,. /, . . .

,. ., , , „ ,. , during heavy rain, lhe total population ol eggs
comparisons were limited to collections made . . , ,. , , „ „ , ,

.,, . , , i j ivt , ,. Tl ■ was estimated to decline about 50 percent between
within the area sampled on November 16. It is , , . . . ,„ ,, \ , ,.
c .,. ., c -\€ x l-i these dates. Associated with this decline were
tor this reason that estimates ot M, given in table A

1 1 differ slightly from the estimates given in tab]

e increases in fa and M,.. The period of heavy rain

Table 11. — Estimates of the population parameters E', P,

p'o, and Mi used to evaluate mortality of 1959 brood year eggs and

larvae possibly caused by movement of bed materials

Spawning area and date of observation

Number of
occasions pre-
cipitation was
more than
4 inches in
72 hours

Number of dead plus
live eggs per square

meter (F' and P)

Fraction of points

containing fewer than

35 eggs per square

meter (p'o)

Total mortality (A/r)

Mean

90-percent

confidence

limits of

the mean

Mean

90-percent
confidence
limits of
the mean

Mean

90-percent

confidence

limits of

the mean

Intertidal Harris River: i

»393

3288
3 323

3 159
3 169
3 106

3 31
30

3 705
3 346
3 530

3 24
2 229

3 11

to
October 6 _

None

±105
±138
<±77
< ±46

0.59
.58
.65
.65

±0.09
±.]2
±.18
±.09

0.30
.28
.64
.73

±0.26

to
October 20..

None

±.33

(±.20

to
February 26

4 ±.08

Upstream Harris River:

None

±26

.93

±.05

.73
1.00

±.23

Intertidal Indian Creek:

to
October 10 ___-___.. ... _._ _ ...

None

±130

±206

±18

.59
.51
.91

±.09
±.13

±.06

.52
.27
.97

±.18

±.29

to
Fehruary 29 ___ ._

±.03

Intertidal Twelvemile Creek:

to
October 27

None

±17
±1

.99
1.00

±.06

.95
.99

±.07

±.002

1 Includes 75 percent of the area described in table 1.

• Expected number of specimens based on potential egg deposition (E

3 Estimated number of live plus dead specimens in the spawning bed
1 These limits were set with log-transformed data.

(P).

SPAWNING BED ENVIRONMENT OF PINK AND (

:hum sai

jMON

515

Figure 9. — Debris deposited in intertidal Indian Creek by the December 1959 flood.

in early December appeared to result in little ad-
ditional loss of eggs or larvae from intertidal
Harris River.

The period of heavy rain in November was not
associated with high egg mortality in intertidal
Indian Creek, but the period of heavy rain in
December was associated with high mortality of
eggs and larvae. After high water had receded in
December, large numbers of eggs and larvae
scoured from the Indian Creek, streambed were
observed by workers along the banks. About 90
percent of live eggs and larvae in the intertidal
Indian Creek spawning bed at the time of high
water in December 1959 were probably destroyed.
A factor contributing to this high mortality ap-
peared to be the breaking up of a natural log jam
located a short distance above the intertidal
Indian Creek spawning area and the subsequent
deposition of debris from this jam in the spawning
area. Figure 9 shows some of the debris deposited
in intertidal Indian Creek. Turbulence created
by the stream flowing around this debris was be-
lieved to have been mainly responsible for causing
the stream to alter its course at several locations,

washing out or burying deeply a large percentage
of eggs and larvae present.

There was evidence that gravel movement
caused high mortality in upstream Harris River.
No live or dead eggs or larvae were collected from
68 points sampled in February 1960. Other
evidence of widespread gravel movement in up-
stream Harris River was obtained from studies on
size composition of bottom materials. There was
a significant reduction in volumes of fine sands and
silts in bottom materials during high water in
autumn 1959 (McNeil and Ahnell, 1964).

I960 Brood Year

Periods of highest intensity rainfall occurred
between October 9 and 22. Intertidal Harris
River, Indian Creek, and Twelvemile Creek were
sampled in autumn 1960 before and after high
water (table 12).

Estimated total abundance of eggs in inter-
tidal Harris River, as in the previous 2 years,
declined about 50 percent in association with high
water. The mean fraction of points containing
fewer than 35 eggs per in.- increased 0.16 after

516

U.S. FISH AND WILDLIFE SERVICE

Table 12. — Estimates of the population parameters E', P, p'o, and Mt used to evaluate mortality of 1960 brood year eggs and

larvae possibly caused by movement of bed materials

Number of

occasions

precipitation

was more

than 4 inches

in 72 hours

Number of dead plus
live eggs perm.:

(£' and P)

Fraction of points
containing fewer than

35 eggs per ml (p'o)

Total mortality

Spawning area and date of observation

Mean

90-percent

confidence

limits of

the mean

Mean

90-percent

confidence

limits of

the mean

Mean

90-percent

confidence

limits of

the mean

Intertidal Harris River:

'735

2 538

258

i 708

2 436

J380

'381

114

103

None

±132
±72

0.33
.49

±0.08
±.08

0.29
.69

±0.18

±.09

Intertidal Indian Creek:

None

±146

±162

.52
.47

±.09
±.11

.44
.50

±.20

Intertidal Twelvemile Creek:

None

±66
'±31

.68
.68

±.11
±.11

.71

.75

±.17

a ±.08

■ Expected number of specimens based on potential egg deposition (£')•

-' Estimated live plus dead specimens in the spawning bed (P).
' These limits were set with log-transformed data.

heavy precipitation in 1960; while in 1958 and
1959 the increase was about 0.10. The difference
between an increase of 0.16 and 0.10, however,
was not statistically significant in these instances.
As in 1958 and 1959, on occasions when there
was no movement of temporarily stationary
debris with high water, eggs and larvae in inter-
tidal Indian Creek apparently suffered little mor-
tality. There was also no evidence of mortality
associated with flooding in Twelvemile Creek in
1960, although large numbers of eggs had appar-
ently disappeared before high water.

FREEZING OF INTRAGRAVEL WATER AND
MORTALITY

The study streams freeze usually in December,
January, and February. Hence, mortality attrib-
utable to freezing must occur either during or
after hatching.

Maximum daytime air temperatures were used
as as index of severity of freezing. Periods when
day time temperatures remained below freezing for
two or more consecutive days were determined
from air temperature records obtained at Hollis
by the Northern Forest Experiment Station
(table 13). Freezing was most severe in winters
1956-57 (1956 brood year) and 1958-59 (1958
brood year).

1956 Brood Year

There was evidence of high mortality from
freezing in whiter 1956-57. Estimates of M, for
the 1956 brood year in each of the study streams
are summarized in table 5. Mean values of Mr
were found to increase between late November
1956 and late February 1957 as follows:

A A

Mr=0.27 to Mr=0.50 in intertidal Harris
River.

A A

.Ur = 0.10 to Mr=0.75 in intertidal Indian
Creek.

A A

Mr=0.27 to Mr=0.41 in intertidal Twelve-
mile Creek.

Table 13. — Periods of daytime freezing and associated
precipitation at Hollis, Alaska 1956-61 '

Dates when maximum temperature was
less than 0° C.

Mean

temperature

at 5 p.m.

Precipitation

Winter 1956-57:

Dec. 3-12

Jan. 7-13

°C.

-4°
-6°
-7°
-6°

Indie*
-'■_'. 03
0

Jan. 20-26

Feb. 22-25

Winter 1957-58:

Winter 1958-59:
Jan. 1-8

-5°

Winter 1959-60:

Winter 1960-61:

i Data provided by Northern Forest Experiment Station, U.S. Forest
Service, Juneau, Alaska.
-' Fell as snow, given as inches of rain.

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

517

Two classes of dead eggs and larvae not present
in November samples were found in February
samples: dead eggs with well-developed embryos
ready to hatch and dead larvae. Death of eggs
containing the well-developed embryos occurred
after November sampling and before hatching in
December.

This prehatching mortality occurred in con-
junction with the December 3 to 12 freezeup.
The observed posthatching mortality may have
been caused, for the most part, by the subsequent
more severe periods of freezing in January and
February.

I have already summarized in table 5 the
estimated fractions of 1956 brood year eggs and
larvae dying early, shortly before hatching, and
after hatching. Assuming that mortality at and
after hatching was caused by freezing, I estimated
mortality of the 1956 brood year from freezing to
be about 23 percent in Harris River riffle A, 65
percent in Indian Creek riffles B and C, and 14
percent in Twelvemile Creek riffles D and E.

I visited the study streams during the February
22-25 freeze. Except for an occasional exposed
riffle, they were coated with ice several inches
thick. Freezing appeared to have a greater effect
on Indian Creek spawning beds than on Harris
River and Twelvemile Creek spawning beds. I
attempted to drive metal rods into the Indian
Creek streambed at a number of locations. The
gravel was often frozen, particularly where exposed
by drying of the stream. Anchor ice also had
formed at several points examined.

One important conclusion to be drawn from
these data is that mortality associated with
freezing was highest in the stream having the
lowest minimum discharge (4 c.f.s. in Indian
Creek as compared with 12 c.f.s. in Twelvemile
Creek and 22 c.f.s. in Harris River).

1958 Brood Year

Freezing occurred after hatching in January
1959. Sampling was undertaken in March 1959
(2}i months after freezing), and the possibility
that larvae killed by freezing had decayed before
sampling could not be ignored. Therefore, the
best evidence of winter mortality possibly as-
sociated with freezing may he estimates of M,
which are summarized in table 14.

In intertidal Harris River, mortality was high
before freezing and there was no evidence of

518

Table 14. — Estimated total mortality of 1958 brood year pink
and chum salmon eggs and larvae before and after freezing
in winter 1958-59

Spawning area and date

Mean

90- percent

confidence

limits of

the mean

Intertidal Harris River:

Dec. 20, 1958

0.84
.62

0
.64

.99
.99

±0.21

Apr. 5, 1959

±.29

Intertidal Indian Creek:

Nov. 15, 1958

1 ±.39

March 28, 1959..

±.28

Intertidal Twelvemile Creek:
Dec. 28, 1958

± 01

March 24, 1959

±.01

1 This limit was set with log-transformed data.

additional mortality over winter. Intertidal In-
dian Creek, on the other hand, experienced high
mortality over winter, thus supporting earlier
findings with 1956 brood year eggs and larvae.
There was no evidence of winter mortality in
intertidal Twelvemile Creek, but because of the
scarcity of larvae in the spawning bed, it is
highly unlikely that mortality would have been
detected here.

Other Brood Years

According to Hollis ah temperatures, there
were no prolonged periods of freezing that would
affect eggs and larvae of the 1957, 1959, and 1960
brood years. An examination of data on mortality
revealed little evidence of mortality possibly
caused by freezing.

There was no evidence of winter mortality of the
1957 brood year. Prewinter and post winter
pooled estimates of M, for riffles B, C, E, and F
and then 90-percent confidence limits were:

Mr (pooled for November)=0.69±0.19
Mr (pooled for March) =0.57 ±0.24

With regard to the 1959 brood year, there was a
rather high incidence (IS percent) of dead larvae in
samples collected from intertidal Harris River on
February 26, 1960, but a low incidence (less than 1
percent) of dead larvae collected in samples from
intertidal Indian Creek. Factors other than
freezing probably were responsible for the mor-
tality observed in intertidal Harris River because
temperatures were mostly above freezing in winter
1959-60, and few dead larvae were found in inter-
tidal Indian Creek. Scarcity of eggs and larvae in

U.S. FISH AND WILDLIFE SERVICK

Twelvemile Creek spawning areas made it im-
practical to evaluate winter mortality there.

Only a small number (about 1 percent) of 1960
brood year larvae collected in late winter 1961 from
intertidal Harris River and Indian Creek were
dead. Of 933 larvae collected in intertidal
Twelvemile Creek, 9.4 percent were dead, but
most dead larvae were found in one redd. Factors
other than freezing were suspected of having
caused their death.

An experiment indicated that little or no freez-
ing of intragravel water occurred in winter 1960-
61. One-half-dram vials were filled with water
and buried 5 and 10 inches in spawning beds
during autumn 1960. They were recovered in
spring 1961 and examined for breakage caused by
water expanding during freezing. The recovery
of a broken vial was used to indicate occurrence of
freezing at the point of burial. Breakage from
causes other than freezing was minimized by en-
closing vials in latex tubing. Sixty-three vials
were recovered from intertidal Indian Creek, 36
from intertidal Harris River, and 30 from inter-
tidal Twelvemile Creek. There were no broken
vials in the lot. This experiment provided further
evidence that intragravel water did not freeze in
winter 1960-61.

DISCUSSION AND CONCLUSIONS

There is evidence that mortality of pink and
chum salmon from egg deposition to fry migration
is seldom less than 75 percent and commonly ex-
ceeds 90 percent in small coastal streams. Fresh-
water mortality, therefore, may place more severe
restrictions on production of pink and chum
salmon than natural salt-water mortality.

A thorough understanding of the ecological and
physiological requirements of pink and chum
salmon eggs and larvae is necessary for evaluating
the potential of spawning beds to produce fry.
It has been a goal of these studies to determine the
relative importance of certain factors affecting
quality of the spawning bed environment and fry
production.

OXYGEN SUPPLY AND RELATED FACTORS

It is evident from a review of the literature that
the oxygen supply rate to an egg or larva is a
function of oxygen content and velocity of flow of
intragravel water, both of which are affected by a

complex of interacting factors. It would appear
that oxygen privation is more critical in embryonic
than in larval stages. For evaluating mortality
possibly resulting from an oxygen deficiency,
observations on mortality were based primarily
on the population of eggs present in the spawning
bed at the time of sampling. Where large numbers
of eggs had disappeared from spawning beds before
sampling, or where density of females spawning
was light, it was not possible with the sampling
scheme used to obtain data adequate to evaluate
prehatching mortality possibly associated with
the availability of oxygen. Inadequate data for
the intertidal Twelvemile Creek and upstream
Harris River and Twelvemile Creek spawning
areas were of limited value in evaluating mortality
possibly due to oxygen privation, and observations
were made mostly in intertidal Harris River and
Indian Creek.

Data on (1) dissolved oxygen content of intra-
gravel water, (2) streambed gradient, and (3)
organic content, size composition, and permeability
of bottom materials showed more favorable oxygen
supply in intertidal Indian Creek than in intertidal
Harris River. Furthermore, results of mortality
studies suggested that prehatching mortality not
associated with the disappearance of eggs was
lower in intertidal Indian Creek than in intertidal
Harris River. Hence, there was general agree-
ment between observations on physical quality of
the spawning bed environment and egg mortality.

An opportunity arose in 1957 to evaluate the
relation between prolonged low streamflow during
spawning and egg mortality. In this instance,
unusually low levels of dissolved oxygen in intra-
gravel water were observed during the spawning
period. The evidence relating an exceptionally
high egg mortality to low streamflow corroborated
the findings of other workers (Brett, 1951 ; Neave
and Wickett, 1953; Wickett, 1958).

In these studies it was not possible to demon-
strate a direct dependence of egg mortality and
population size. In 1957, when spawning den-
sities were extremely low and egg mortality was
unusually high, there appeared to be some justifi-
cation for suggesting that a minimum number of
spawners is required to reduce the overall bio-
chemical oxygen demand through the removal of
organic detritus from spawning beds (Ricker,
1962). Additional research will be required to
resolve this question.

SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

519

STABILITY OF THE SPAWNING BED

Instability of the spawning bed was an impor-
tant cause of egg and larval mortality in the study
streams. There was no apparent relation between
gravel composition and stability during flooding,
and high mortality occurred in spawning beds
composed of coarse and fine materials. Change
in position of temporarily stationary debris caused
gravel movement, but the presence of floating
debris had little or no effect on gravel movement.

The influence of temporarily stationary debris
on the stability of bottom materials was studied in
Maybeso Creek (fig. 4), a stream located near
Hollis (Bishop and Shapley, 1963). The results
of this study gave further support to relations ob-
served between movement of wood debris and
mortality of eggs and larvae in Harris River,
Indian Creek, and Twelvemile Creek.

High discharge may be a common cause of mor-
tality among salmonid eggs and larvae. In New
Zealand, Hobbs (1937) concluded that floods
seldom destroyed salmon and trout redds, but at
times accounted for a partial failure of a brood
year. At Sagehen Creek, Calif., a flood in Decem-
ber 1955 destroyed brook trout, Salvelinus fonti-
nalis, and brown trout eggs, causing the complete
failure of the zero age group of these species in
1956 (Needham and Jones, 1959).

Observations on dislodgment of salmon eggs and
larvae from British Columbia and Southeastern
Alaska streams during flooding also have been
reported. After flooding, Withler (1952) found
preemergent sockeye salmon fry washed from a
tributary of Babine Lake, British Columbia, and
Wickett (1959) reported the observation of coho
and chum salmon eggs on banks and in bushes
along the Qualicum River, Vancouver Island.
Floods at Sashin Creek in 1941 and 1943 were
thought to have killed many pink salmon eggs and
larvae (Hutchinson and Shuman, 1942; Davidson
and Hutchinson, 1943).

FREEZING OF INTRAGRAVEL WATER

Although freezing has been considered an im-
portant cause of mortality, except for Neave
(1947), Smirnov (1947), and Semko (1954), little
direct evidence showing freezing to be an im-
portant cause of pink and chum salmon egg and
larval mortality has been reported. 1 found that
freezing caused high mortality of 1956 brood year
eggs and larvae, particularly in intertidal Indian

520

Creek. There was also an indication that the
1958 brood year experienced similar high mortality
in Indian Creek. Winters of 1957-58, 1959-60,
and 1960-61 were mild by comparison, and there
was little or no evidence of mortality from freezing.
It was apparent that freezing exerted the great-
est influence on mortality in the stream having the
lowest minimum discharge. Further study may
reveal that certain spawning areas are unproduc-
tive because of low discharge during periods of
freezing. There was no evidence of high mortality
from freezing during winters that maximum day-
time air temperatures remained above 0° C.

SUMMARY

1. The available evidence indicates that high
mortality of eggs and larvae greatly limits the
abundance of juvenile pink and chum salmon.
Proper management of pink and chum salmon
fisheries will depend in part on a thorough under-
standing of the factors affecting the potential of
spawning beds to produce fry. Field studies of egg
and larval mortality are important because they
provide information on time and magnitude of
mortality that can be associated with causative
factors.

2. In the study streams, egg mortality after the
end of spawning seldom exceeded 20 percent in the
absence of low levels of dissolved oxygen, freezing,
or high water. There was evidence that mortality
attributable to oxygen privation was highest where
water circulation within the spawning bed was
impaired.

3. Low levels of dissolved oxygen in intragravel
water as well as high egg mortality occurred with
low flow during and shortly after spawning. The
resulting mortality of eggs was estimated to vary
between 60 and 90 percent in the spawning areas
sampled.

4. Movement of bottom materials during high
water was an important cause of mortality, which
was most severe where temporarily stationary
debris shifted position within the flood plain.
Mortality from movement of bottom materials
was estimated to exceed 90 percent in one instance.

5. Freezing was an important cause of mortality
only when maximum daytime temperatures re-
mained below 0° C. for at least 2 consecutive days.
Mortality from freezing was highest in the stream
having the lowest minimum discharge, and was
estimated to approach 65 percent on one occasion.

U.S. FISH AND WILDLIFE SERVICF.

ACKNOWLEDGMENTS

Many FRI staff members and personnel at the
Northern Forest Experiment Station, U.S. Forest
Service, assisted in the planning and field sampling.
William L. Sheridan was project leader from 1956
to 1959 and planned much of the early field work.
William F. Royce, Donald E. Bevan, and Max
Katz of the College of Fisheries, University of
Washington, contributed many helpful suggestions
during the preparation of the original manuscript.
Warren C. Pellett and Jack Cassell of FRI deserve
special mention because they endured the harsh
autumn and winter weather of Southeastern
Alaska to accomplish much of the field work.

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1937. Natural reproduction of quinnat salmon,
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SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

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Hunter, Jekrt G.

1959. Survival and production of pink and chum
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1942. Reproduction of pink salmon at Little Port
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1941. The influence of temperature upon the com-
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1920. To what extent are the physiological effects
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1956. The physical effect of logging on salmon
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1956. The analysis of trawl haul statistics with
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1962. Inshore-marine and freshwater life history
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1941. The comparative physiology of respiratory
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Krogh, August, and Hans H. Ussing.

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LlNDROTH, ARNE.

1942. Saurstoffverbrauch der Fische. II. Ver-
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1948. Concept of the graded river. Bulletin of

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1962a. Mortality of pink and chum salmon eggs

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402, 15pp.

McNeil, William J., and Warren H. Ahnell.

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1962. Effects of logging on pink salmon and spawn-
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1962. Freshwater survival of pink salmon at Sashin
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1953. Principles affecting the size of pink and chum
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1953. Factors affecting the freshwater development
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1948. Efficiency of natural propagation of the pink
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Ricker, W. E.

1958. Handbook of computations for biological sta-
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1956. Some effects of sea water and temperature on
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Semko, R. S.

1954. Zapasy zapadnokamchatskikh lososei i ikh
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U.S. FISH AND WILDLITE SERVICE

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1961. Temperature relationships in a pink salmon
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1962a. Waterflow through a salmon spawning riffle
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407, 20 pp.

1962b. Relation of stream temperatures to timing
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1960. The influence of water velocity on the develop-
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49 pp.

Silver, Stuart Jayson.

1960. The influence of water velocity and dissolved
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Duodoroff.

1963. Dissolved oxygen requirements of developing
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Smirnov, A. G.

1947. Composition of the stocks of Amur salmon and
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1961. Fluid flow in the open-surfaced porous bed.
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1962. Interchange of stream and intragravel water in
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1954. The oxygen supply to salmon eggs in spawning
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1952. Sockeye reproduction in a tributary of Babine
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1957b. Blue-sac disease investigations: microbiology
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1948. Beitriige zur Toxikologie der Fische. II. Ex-
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SPAWNING BED ENVIRONMENT OF PINK AND CHUM SALMON

523

CORRECTIONS FOR RECENT ISSUES OF THE FISHERY BULLETIN

Volume 63, No. 3

Page 561, table 11. In the head of second

column the M should have a subscript 1,

not superscript 1.
Page 562, left column, 6th line from bottom.

In the first exponent of the equation for p,

the M should have a subscript (Mi).
Page 569, right column, 6th line from bottom.

The product quantity 2.894 (1.4577) should

be 2.894 (.4577).
Page 659, left column, 2d paragraph. Both

x's, in equation should read x.
Page 663, right column, 2d full paragraph,

9th line. The figure is 629,000.
Page 666, right column, last line. Equation

should read: (0.22) (0.04) + (0.78)P^ =0.48

or PA =0.60.
Page 667, left column, 3d paragraph, 10th

line. Should read: to the model given

earlier (page 661).

Page 669, right column, 4th and 5th lines
should read: the Commander Islands re-
covery data (appendix table 2).

Volume 64:

Page 215, right column. The author Florkin,
Marcel, should be moved up 4 lines to
appear before the 1934a.

Page 220, figure 197. The scale should read
0 to 5.0.

Page 299, figure 268. Legend should read:
Slightly slanted tangential section through
the opening and adjacent portion of the
ovary of C. virginica. Oviduct with two
eggs at lower left side. Kidney reservoir
at lower right. Ovary follicles at top.
Drawn semidiagrammatically from a photo-
micrograph of a preparation. Kahle,
hematoxylin-eosin.

Page 349, figure 329. The identification
letters, a through f, should be added below
the individual figures starting with upper
row and reading from left to right.

FISHERY BULLETIN: VOLUME 65, NO. 2

525

U.S. GOVERNMENT PRINTING OFFICE: 1966— 0-771-71I

LIFE HISTORY OF THE SPINY DOGFISH

By Albert C. Jensen, Fishery Biologist (Research)'
U.S. Bureau of Commercial Fisheries Biological Laboratory, Woods Hole, Mass.

ABSTRACT

The spiny dogfish, a small shark, is a costly nuisance
to commercial fishermen off both coasts of the United
States. Data on the species' life history were gathered
from the literature and from original studies and
assembled in one report as a basis for possible future
management. The species reaches a maximum length
of 100-124 cm. and a maximum weight of 7-10 kg.
The females are slightly larger than the males. Dogfish
are known to migrate in large schools and, occasionally,
to travel long distances. Tagging studies suggest they
move offshore in the winter and inshore in the summer.
They are opportunistic feeders with a diet list that
includes fishes and crustaceans. Age determinations
from interpretation of spine markings indicate the
dogfish are long lived with some individuals living for

20 or 30 years. The species Is ovoviviparous and mating
takes place in the cold months. After a nearly 2-year
gestation period, a female gives birth to 3-11 pups, each
about 25 cm. long. Natural mortality rate apparently
is low, and the species has few natural enemies. In
1944 more than 40 million pounds of spiny dogfish were
landed as a source of vitamin A. Today about 2 million
pounds are landed. In the United States the species
has limited value as an industrial fish and even less value
as a food fish. It is edible, however, and is valued as
food in some European nations. Management of the
spiny dogfish off North America is indicated to reduce
the damage it causes to more valuable commercial
fisheries.

The spiny dogfish Squalus acanthi as L., a small
shark of the family Squalidae, has been one of the
most intensively studied fishes, but one in which
extensive knowledge is lacking. The species is
studied by college students in zoology, ichthyology,
comparative anatomy, and vertebrate taxonomy
and is a favorite experimental animal for physio-
logical studies including pharmacological toxicity
tests. FewT comprehensive biological studies of
this fish have been made, however, except for
Ford's (1921) study at Plymouth, England, Tem-
pleman's (1944) study in Newfoundland, and the
studies made by Bonham, Sanford, Clegg, and
Bucher (1949) in the State of Washington. In
general, most of the published reports represent
isolated observations or extremely specific studies.
As a result, we know, for example, the function
of the rectal gland of the spiny dogfish (Burger

1 Present address: Institute of Marine Science, University of Miami, Fla.
Note. — Approved for publication February 9, 1965.

and Hess, 1960), but we do not know the winter-
ing grounds of the species ; we know the mechanism
controlling movements of the spiral intestine
( Sawyer, 1933 ) , but we do not know the relation-
ship between the groups of dogfish in any one area.

This paper is an attempt to organize and sum-
marize the available information, to which I have
added additional original data from recent studies
of the spiny dogfish in the Northwest Atlantic.
This report is undoubtedly incomplete, brat will
serve as a starting point for other studies and help
the researcher who is not completely familiar with
the literature to interpret future observations.

As a convenient method of handling the infor-
mation, the various phases of the life history of
the fish are taken up in turn. Because the species
is distributed throughout the Northern Hemi-
sphere (Bigelow and Schroeder, 1948), I have
reviewed reports from both the Atlantic and Pa-
cific Oceans. Some consideration has been given,

FISHERY BULLETIN! VOLUME 65, NO. 3

527

as well, to the role of the spiny dogfish in the com-
mercial fishery.

Much of the information reported here is of
interest solely because it adds to man's fund of
knowledge about, the species; however, some of the
information has more concrete implications for
our commercial fishermen. This latter considera-
tion has been aptly summed up by Bigelow and
Schroeder (1948), who state:

"From a practical aspect the spiny dog in the
"Western Atlantic is chiefly important because it
is undoubtedly more destructive to gear and inter-
feres more with fishing operations than does any
other fish — shark or teleost."

DESCRIPTION

The spiny dogfish is typically sharklike in ap-
pearance (fig. 1). In Western Atlantic waters it

grows to a length of about 50-90 cm. and weighs
3.5-4.9 kg., with a maximum of about 100 cm. and
7.3-9.8 kg. The females are slightly larger than
the males (Bigelow and Schroeder, 1953). In the
Pacific Ocean, off the west coast of the United
States, the males reach a maximum of about 100
cm. and 3.9 kg., while the females reach a maxi-
mum of about 124 cm. and 9.8 kg. (Bonham et ah,
1949).

The upper part of the fish is slate colored, some-
times tinged with brown, with irregular rows of
small white spots on each side. The white spots
are generally typical of younger fish and may be
lacking on older individuals. A distinguishing
feature of this shark is the presence of two sharp
spines, one anterior to each dorsal fin, the rear
spine longer than the front spine. Halstead
(1959) reports that a venom gland is located on

r»2s

Figure 1. — The spiny dogfish, Squahia acanthias.

U.S. FISH AND WILDLIFE SERVICE

the upper posterior part of each spine. He cites
no case histories of injuries, however. The spines
presumably are used in defense and are capable
of inflicting a painful wound.

Spiny dogfish frequently are confused with the
smooth dogfish, Mu-sfe/us canits (Mitchill), a mem-
ber of the family Triakidae, although examination
of the two species will clearly separate them. The
smooth dogfish, as the name implies, lacks the
sharp dorsal spines. It is a lighter color than the
spiny, although it has great ability to change color
to match its surroundings. Above a white sandy
bottom it usually is a translucent, pearly shade;
over a dark bottom it will have a darker color. In-
dividuals, in general, tend to be larger than spiny
dogfish; smooth dogfish are 89-137 cm. long with
a few attaining 152 cm. in length. Food of the
smooth dogfish is mostly large Crustacea, espe-
cially lobsters and crabs, although it also eats small
fish such as menhaden and tautog. It is a coastal,
warm water species that ranges in the Western
Atlantic from Uruguay and southern Brazil to
Cape Cod. It is one of the sharks that develops a
placental attachment between the embryos and the
mother; thus it is truly viviparous. The smooth
dogfish is of little concern to commercial fishermen.

DISTRIBUTION

Distribution of the spiny dogfish has been, until
recently, somewhat obscured by the question of its
specific identity. Many ichthyologists held that
there were two distinct species, S. acanfJiias in the
North Atlantic. Ocean and S. suckleyi in the North
Pacific Ocean. Bigelow and Schroeder (1948)
noted that although it was not entirely clear how
the two species were related, they had not ob-
viously differentiated themselves specifically dur-
ing the period since their ranges had become dis-
continuous. The prevailing opinion today is that
the two populations represent but a single species,
S. acanthiii.s, which occurs in both the Atlantic and
Pacific Oceans ( American Fisheries Society, 1960 ) .
Briefly, the distribution may be expressed as both
sides of the North Atlantic, chiefly in temperate
and subarctic latitudes, and also on both sides of
the North Pacific, in similar latitudes (fig. 2), with
close allies in corresponding latitudes in the South-
ern Hemisphere. The species is of minor eco-
nomic importance in the Southeast Atlantic, off
the West Coast of Africa, but fairly important in

Mediterranean Atlantic waters.- It occurs chiefly
in continental, as contrasted with oceanic, waters,
anywhere between the surface and the bottom
down to 165-185 meters (Bigelow and Schroeder,
1948) and has been found as deep as 290 meters
( see table 1 ) .

Figure 2. — Distribution of the spiny dogfish in
Northern Hemisphere.

the

The distribution in the Northeast Atlantic is
described in detail by Bigelow and Schroeder
(1948) as follows: off France, north to Ireland,
Scotland, southern Scandinavia, the English
Channel, and the North Sea, from there eastward
to the Kattegat. The spiny dogfish rarely enters
the Baltic Sea. It is plentiful around the Orkney
Islands, the Faroes, and south and east of Iceland
(but less to the north and west), and is found off
Norway to the Murman coast. It is also generally
distributed in the Mediterranean Sea and the
Black Sea.

In the Northwest Atlantic the spiny dogfish is
found in coastal waters from Cape Lookout, N.C.,
northward around Nova Scotia, along both the
northern and southern shores of the Gulf of St.
Lawrence, past the Strait of Belle Isle to southeast

2 Food and Agriculture Organization of the United Nations.
1957. The present status of knowledge of the living resources
of the marine waters of the West Coast of Africa. Fisheries
Division, Biology Branch. Rome. Italy, 30 pp. [Unpublished
processed report.]

LIFE HISTORY OF SPINY DOGFISH

529

Labrador (Bigelow and Schroeder, 1948). It is
common northward along the coasts of Newfound-
land. There is no record of its occurring along
the coast north of Hamilton Inlet. Offshore it
occurs in season on Nantucket Shoals, Georges
Bank, Browns Bank, the Nova Scotian banks, and
the Newfoundland banks. It was also recorded on
the west coast of Greenland to Sukkertoppen and
Holsteinborg. Hansen (1949) reports that dog-
fish were formerly a rarity around Greenland, but
in the 1930's some were caught in several places on
the southwest coast and in the autumn of 1947,
around Sukkertoppen.

Local observations of spiny dogfish, and their
seasonal occurrence, are reported by Perley
(1852), Stafford (1912), Cox (1921), and Jeffers
( 1932) . Each of these authors noted that the ap-
pearance of dogfish usually indicated an end of
commercial fishing for food fishes.

Table 1. — Water temperature and dogfish catches of 100 or
more by otter trawl from research vessels in the Northwest
Atlantic from Nova Scotia to the offing of New York,
1948-59

Date

Feb. 3, 1959...
Do

Apr. 22, i950..

Apr. 23, 1950. .

Apr. 26, 1950..
Do

May 1, 1950...

Do..

May 2, 1950...

May 13, 1950..

May 14, 1950.

May 15, 1950.

May 16, 1950.
Do

May 17..1950.

June 14, 1955-.

Weighted average-

July 29, 1949 -
Aug. 1, 1950...

Aug. 2, 1950...
Aug. 5, 1950...
Aug. 4, 1948—
Aug. 5, 1948...

Oct. 8, 1958.--
Oct. 9, 1958 ...
Oct. 16, 1948 .
Oct. 17, 1948 .
Oct. 20, 1959. .
Oct. 30, 1949..

Oct. 31, 1948 .
Nov. 5, 1948. .
Nov. 17, 1956.

Do
Dec. 3, 1948...

Weighted average-

Depth

Meiers

180

152

122

110

219

189

183

177

201

110

142

113

103

67
85
85
94
293
58
33
40
204
222
24
37
55
74
76
60
55
61
61
56
56
85

Bottom
tempera-
ture

9.4
11.7
9.4
7.2
7.8
7.2
8.9

8.9
4.4
11.1
11.1
11.1
5.0
7.2
11.1
7.8
6.7
5.6
6.1

8.3

10.6
7.8
8.3
8.9
6.1
6.7
13.3
11.7
7.8
7.8
12.2
8.3
11.1
15.6
13.3
14.4
15.6
15.0
14.4
13.3
16.7

Catch of
dogfish

Number
428
367
560
100
103
224
372

1,200
475
269
420

1,476
152
150
610
258
110
120
140
156
110

3,637
224
455
146
234
123
131
210
900
122
374
101

1,050
248
100
283
115

1,561
187
160
211
190

In the Pacific Ocean, Bigelow and Schroeder
(1948) report that the spiny dogfish is found on
". . . both sides of the Northern Pacific south to
California, Japan, Northern China and the
Hawaiian Islands."

MIGRATIONS

The spiny dogfish is a gregarious fish and occurs
in schools containing large numbers of individ-
uals. Usually the schools are composed of: (1)
very large, mature females; (2) medium-sized in-
dividuals, all mature males or all immature fe-
males; or (3) small immature individuals of both
sexes in about equal numbers (Bigelow and
Schroeder, 1953 ) . Hickling ( 1930) , in his studies
of spiny dogfish collected off the southern coast of
Ireland, noted a relation between the size of the
individuals in the schools and the depth of water.
Fish of both sexes, from 30 to 45 cm. long, were
caught in 55 m., while larger fish of both sexes,
from 50 to 89 cm. long, were caught in depths of
164 to 183 m. In general, male dogfish were found
in shallower water than females of the same size.
The exception to this, however, was for the large
pregnant females that were found migrating into
shallower water to bear their young.

The. appearance of dogfish in our northeastern
coastal waters is a rather sudden event. One day,
in a given area, there will be fine cod and haddock
fishing; the next day there will be nothing but
dogfish. They appear as early on Georges Bank
(March- April) as they do along New Jersey
(March) (Bigelow and Schroeder, 1953). Dog-
fish are spring and autumn transients only in the
southern part of their range, from New York to
North Carolina, and in the Cape Cod area they
are mostly transients, moving to the north in the
spring and to the south in the autumn.

In Newfoundland waters they first begin to ap-
pear in June, off the southern end of the island
(Templeman, 1944). The largest fish— mature
and probably pregnant females — appear first.
The mature males appear in the late autumn. As
the season progresses, dogfish appear farther
northward along the coast and are off Labrador
by September. In general, dogfish are plentiful
around Newfoundland from June through No-
vember or December.

The nature of the dogfish's seasonal migration —
coastal north-south, offshore-onshore, or a combi-

530

U.S. FISH AND WILDLIFE SERVICE

nation of the two — is not clearly understood.
Part of the problem is the mystery of where the
dogfish spends it winters. Bigelow and Welsh
(1925) stated, "The winter home of the Gulf of
Maine dogfish is still to be learned." They ex-
amined the evidence, including the presence of the
adults in deep water in Long Island Sound in mid-
summer, the almost simultaneous appearance of
the fish all along the coast north of North Carolina
in the spring, and the capture of dogfish by the
Albatross, February 1920, in 164 to 365 m. along
the continental edge off Chmcoteague, Va., and
off Delaware Bay, and concluded that this ". . .
argues for an on-and-off rather than a long-shore
migration, with the deep water off the continental
slope as their winter home."

More recent evidence of the presence of dogfish
in deep water during the winter has been accumu-
lated from observations of dogfish off the Middle
Atlantic and New England States (Bigelow and
Schroeder, 1936, 1948, 1953). In January 1961,
spiny dogfish were taken in an otter trawl by the
Bureau of Commercial Fisheries research vessel
Delaware in 158 to 183 m. along the edge of the
Continental Shelf 80 miles south of Martha's
Vineyard.

At times, however, dogfish may come into shal-
low water in the winter. Collins (1883) quotes
an item in the newspaper "Cape Ann Advertiser"
dated February 10, 1882 : "Immense, schools of
dogfish, extending as far as the eye can reach, have
appeared off Portsmouth, an unusual sight in
winter."

The accumulated wealth of evidence suggests
that temperature governs the seasonal movements
of the spiny dogfish. Bigelow . and Schroeder
(1948) note that dogfish do not appear along the
east coast until the water warms to 6° C. and dis-
appear when the water temperature rises to about
15° C. The preferred range of temperature on
the offshore wintering grounds seems to be 6°
to 11° C.

Survey data (table 1) collected during 1949-59
by the Bureau of Commercial Fisheries Biological
Laboratory at Woods Hole indicate dogfish in the
Northwest Atlantic prefer bottom water tempera-
tures between 7.2° and 12.8° C. (average, 9.8°).
The average temperature at which 100 or more
dogfish per haul were caught during the period

January-June was 8.3° C. ; for the period July-
December, 11.4° C.

The survey data also tend to support Bigelow
and Schroeder's statement that this species winters
in relatively deep water, moving into shoaler water
in summer and fall. The average depth at which
100 or more dogfish were caught during the period
January-June is found to be significantly differ-
ent from the corresponding depth for the period
July-December (134 and 85 m., respectively).

In Alaska waters incidental catches of spiny
dogfish are reported by Hanavan and Tanonaka
(1959) during experimental gill netting for sal-
mon. The dogfish were caught in the Bering
Sea and in the Gulf of Alaska during July and
August when the surface water temperatures
ranged from 7° to 13.3° C.

In waters off Japan, Sato (1935) reports an in-
teresting diurnal migration of spiny dogfish. He
recorded the body temperatures of dogfish caught
in the daytime and at night, on a fishing ground
in depths of 110 to 128 m. Thirty dogfish caught
at night in a surface drift gill net had body tem-
peratures of from 9.5° to 11.2° C. The surface
water temperature at the time was quite similar,
from 9° to 12.2° C. In contrast, 28 dogfish caught
during the day on a longline on the bottom had
body temperatures of from 3.5° to 5.8° C. Unfor-
tunately Sato does not report the water tempera-
ture on the bottom. It seems reasonable to assume,
however, that the bottom water temperature was
within the range of the body temperature of the
fish caught on the bottom and that the dogfish were
rising to or near the surface at night and descend-
ing to the bottom during the day.

In early August 1961, during a cruise of the
Bureau of Commercial Fisheries research vessel
Delaware, dogfish were frequently observed at or
near the surface on many of the inshore Gulf of
Maine fishing grounds (Robert L. Edwards, per-
sonal communication ) . The water temperatures at
the surface were normal for the season (around
15.6° C), but at the bottom they were abnormally
cold (2.8° to 3.9° C. at 73 m.). Few dogfish were
taken in the otter trawl at this time.

Edwards (personal communication) observed
the dogfish appeared at the surface itself late at
night and early in the morning. One morning in
Ipswich Bay they were observed to be harrying
small schools of euphausiids — as many as six to

LIFE HISTORY OF SPINY DOGFISH

531

eight fish circling each school. The numbers of fish
that could be seen at this time were in the thou-
sands. During the day the dogfish retreated to
depths of 3 to 5 fathoms. Several hundred were
handlined from this depth for tagging and for
examining the embryos in the pregnant females.
In the lat« afternoon, occasional fish were again
observed at the surface. South of Cape Cod, the
dogfish were taken again a few fathoms below the
surface. They appeared whenever the otter tra wl
was hauled in and unwanted fish were discarded.

Edwards, Livingstone, and Hamer (1962)
studied the distribution of fishes across the Con-
tinental Shelf from Nantucket Shoals to Cape
Hatteras. Their results indicate that male spiny
dogfish are usually found in cooler water than
the females.

Little is known of the salinity preferences of the
spiny dogfish. Bigelow and Schroeder (1948),
however, note a record of a spiny dogfish that en-
tered a river in Denmark. In their opinion the
water was undoubtedly brackish at least near the
bottom, rather than fresh, since both cod and
Merhwc'tuH were also present in the river at the
same time. Spiny dogfish captured off British Co-
lumbia and studied in the laboratory, were able to
live for more than 1 hour in distilled water and
for nearly 2 hours in tap water (Quigley, 1928a).
The author concludes, "Since the dogfish continued
to breathe for an average of 113 minutes in tap
water and remained active during most of this
time, they probably could escape from a freshwater
stream even if they were to swim into it above
tide water level."

TAGGING STUDIES

Spiny dogfish have been tagged over most of
their range by biologists interested in making pre-
cise determinations of the migration routes of this
fish, and also in learning something of the nature
of the dogfish populations. Tag returns from
most of the experiments have been at a lower rate
than for tagging experiments with commercially
valuable fishes; in most fisheries the dogfish is
either a nuisance to he avoided or, at best, is re-
tained as a very minor pari of the catch. Al-
though many tagged dogfish are undoubtedly re-
captured, most are discarded at sea without having
their tags noticed; consequently, few tags are re-
covered. Tagging returns suggest thai t lie dog-

fish is long lived, for several fish were at liberty
for 10 years. Some individual fish migrated long
distances.

In a British experiment in November and De-
cember 1957, 75 spiny dogfish were tagged with a
yellow plastic tab attached with a braided nylon
loop (Beverton, Gulland, and Margetts, 1959).
The fish were tagged incidentally during a whit-
ing tagging experiment in the northwest part of
the Irish Sea. At the time of the report, after 7
months at liberty, only two tagged dogfish were re-
turned despite the fact that originally the dogfish
appeared particularly robust and little affected by
capture or tagging. No information was given as
to the place of recapture of the tagged fish.

One thousand spiny dogfish were tagged near
the Shetland Islands, north of Scotland, in Nov-
ember 1958 (Aasen, 1960). The mark used was a
yellow slip of polyethylene film with printed text
rolled up as a cylinder and attached to the fish
with a stainless steel bridle in front of the first
dorsal fin. After 2i/o months at liberty, 12 tagged
fish (1.2 percent) were recaptured, most of them
near the west coast of Norway. After 2 years at
liberty, 10.8 percent of the dogfish had been re-
captured. The returns from this experiment,
combined with returns from nearly 3,000 dogfish
tagged in later experiments, yielded a combined
return rate of 6 percent. Aasen (1962) con-
cluded, "It is obvious that most of the fish migrate
towards the Norwegian coast in winter and return
to the grounds northwest of the British Isles in'
summer."

Holden (1962) tagged 278 dogfish in the Irish
Sea during 1957-59, and 15 (5.4 percent) were re-
captured. Most of the winter recaptures came
from the southern part of the Irish Sea, while the
summer and autumn recaptures came from Scot-
land, as far north as the Shetland Islands. Pre-
sumably the dogfish wintered in the Irish Sea and
migrated to mingle with the Norwegian dogfish
north of Scotland in the summer.

Nearly 10,000 dogfish were tagged in the waters
off British Columbia and Washington in the 1940's,
and 655 (6.7 percent) were recovered (Holland,
1957). In general, the tag returns demonstrated
a southward, coastal migration in the autumn and
winter and a northward migration in the spring
and summer. Several long-distance recaptures
were reported from the coastal migrations but the

532

U.S. FISH AND WILDLIFE SERVICE

one outstanding offshore, long-distance migration
that was reported was when a dogfish that had
been tagged off Willapa Bay, Wash., in 1944 was
recaptured near the northern end of Honshu
Island, Japan, in 1952. This is a straight line dis-
tance of 4,700 miles, but the author concluded that
the fish probably followed a great circle route at
accustomed depths along the coastal shelf. Lon-
gevity of the spiny dogfish is suggested by the
above example, a fish at liberty 7 years, and two
other fish tagged in the same experiment, which
were at liberty 8 j'ears and 10 years, respectively.
Dogfish tagging experiments in the Northwest
Atlantic have been reported by Templeman (1954,
1958) for the. Newfoundland-Grand Bank area and
by Jensen (1961) for the Gulf of Maine-Georges
Bank and Browns Bank areas (fig. 3). In the
Newfoundland experiment, 279 females were
tagged near St. John's in July 1942, and, as of
September 1949, 14 fish (5 percent) were recap-
tured. Many of the tagged fish were caught in the
local area and the Maritimes, but two were caught
off Gloucester, Mass. (one in 1942 and one in

1943), a distance of 900 miles, and one was caught
off Cape Henry, Va., in 1947, a distance of 1,300
miles. The last return was from the Strait of
Canso, Nova Scotia, in 1949. Templeman noted
(1954), ". . . most of the tagged fish were mature
females carrying young and the recaptures show
a southward late fall movement of some at least of
these large pregnant females, with presumably a
compensating northward movement in the spring
and early summer." In an earlier report (1944)
he suggested that the dogfish migrate rapidly and
for long distances in the upper layers of the water.

While the tag returns reported by Templeman
indicated a coastwise migration, he did report an
astonishing offshore migration from a later tag-
ging experiment (Templeman, 1958) . A fish that
had been tagged on the southwestern slope of the
Grand Bank in June 1947 was recaptured in Faxa
Bay, Iceland, in August 1957. The straight line
distance between the tagging area and the point
of recapture is over 1,300 nautical miles.

Returns of dogfish tagged in the Gulf of Maine
area have done little to confirm either a north-

70° 65° 60° 55°

Figure 3. — Results of dogfish tagging in the Northwest Atlantic
LIFE HISTORY OF SPINY DOGFISH

50°

45°

533

south or inshore-offshore migration pattern (Jen-
sen, 1961). In these experiments, 155 dogfish
were tagged near Cape Ann, Mass., in July 1956,
and 50 were tagged on Browns Bank in October
1957. To date, nine tags have been returned
(5.8 percent), eight from the 1956 experiment and
one from the 1957 experiment. Most of the tag-
ged fish were recaptured relatively close to the
areas in which they had been released; six were
caught less than 50 miles from the tagging area;
one, 73 miles away ; and another, 140 miles away.
One, however, at liberty nearly 5 years, was re-
captured 200 miles away, on the eastern edge of
Georges Bank. In general, the recaptures suggest
that spiny dogfish return to the same general area
at about the same time of year and the same fish
probably school together for long periods of time.

An interesting recapture was made recently of
a dogfish tagged in a later series of experiments
carried out aboard the Delaware. The fish was
1 of 143 caught on handlines in 18 m. of water,
July 22, 1961. It was tagged and released 3 miles
off Halibut Point, Cape Ann, Mass., and was re-
captured by a commercial otter trawler in 119 m.
on December 30, 1961, in the vicinity of the Hud-
son Canyon. The fish had moved about 250 miles
in 23 weeks and was caught south and offshore of
the tagging area. This recovery adds further
evidence to support the hypothesis that some of
the dogfish that spend the summer in the inner
Gulf of Maine migrate south and offshore to spend
the winter.

Table 2 gives the tagging and recapture in-
formation for 17 spiny dogfish tagged by person-
nel of the Bureau of Commercial Fisheries Bio-
logical Laboratory at Woods Hole. The 17 re-
present the returns from a total of 844 dogfish
tagged in 1956, 1957, 1960, and 1961.

SEROLOGICAL STUDIES

An approach to the identification of spiny dog-
lisli subpopulations, by blood typing techniques,
was made by Sindermann and Mairs (1961). The
authors proposed a two-antigen blood group sys-
tem. They found that individual dogfish collected
in the Gulf of Maine were of blood types Si, S2,
S,S2, or S0. Blood groups of pregnant females
and their unborn pups were compatible, "...
with a simple genetic hypothesis of three alleles,
S1, S'-'. :uid S°, controlling the system." Continua-

tion of the work, complemented with tagging and
other population studies, will make it possible to
determine the existence of reproductively isolated
subpopulations of spiny dogfish. In addition sero-
logical techniques may clarify the relationship be-
tween the various Squakis species and groups
throughout the world.

Table 2.—

Returns of tagged spiny dogfish

Date and locality of—

Time at
liberty

Distance

Tagging

Recapture

Weeks

Miles

July 7, 1956, Boon Island,

July 22, 1957, Cape Ann,

Maine (43°05' N.-70°28'

Mass. (42°44' N.-70°19'

W.).

July 29, 1959, Cape Eliza-

159

beth, Maine (43°28' N.-

70°12' W.).

July 21, 1960, Cape Eliza-
beth. Maine (43°27' N.-

210

70-12' W.).

July 8, 1956, Cape Ann,

Nov. 15, 1956, Cape Eliza-

Mass. (42°48' N.-70°15'

beth, Maine (43°28' N-

W.).

70°10' W.).

Mar. 2, 1957, Cape Ann,

Mass. (42°38' N.-70°17'

W.).

May 22, 1957, Chatham,

Mass. (41°40' N.-69°42'

W.).

July 16, 1959, Cape Eliza-
beth. Maine (42°28' N-

157

70°10' W.).

May 15, 1961, Georges

248

185

Bank (41°33' N.-66°35'

W.).

Sept. 4, 1961, Port Mouton

274

280

Harbour, Nova Scotia

(43°57' N.-64°38' W.).

Oct. 14, 1957, Browns

July 12, 1958. Chance Har-

140

Bank (42°36' N.-65°46'

bour. New Brunswick

W.).

(44°55' N.-66°21' W.).

Julv 8, 1960. Stellwagen

June 13. 1961, Buzzards

Bank (42°13' N.-70°17'

Bav, Mass. (41°32' N.-

W.).

70°40' W.).

May 26, 1961. Woods Hole.

June 11, 1961, Buzzards

Mass. (41°31' N.-70°40'

Bav. Mass. (41°36' N-

W.).

70°50' W.).

June 15, 1962, Montauk
Point, N.Y. (40°54' N.-
71°39' W.).

June 13, 1961, Stellwagen

Aug. 22, 1962, Cape Ann,

Bank (42°25' N.-70°21'

Mass. (42°46' N.-70°39'

W.).

Julv 22, 1961, Cape Ann.

Dec. 30, 1961, Hudson

250

Mass. (42°44' N.-70°36'

Canyon, (39°41'

W.).

N.-72°12' W.).

Aug. 24, 1962. Seguin
Island. Maine (43°38'
N.-69°37' W.).

July 26, 1961. Cape Ann,

Sept. 5, 1961, Portsmouth,

Mass. (42°46' N.-70"41'

N.H. (43°01' N.-70°41'

W.).

FOOD HABITS

Several studies of the stomach contents of spiny
dogfish from many parts of the Northern Hemi-
sphere have shown that it is primarily a fish eater
but will also feed on invertebrates, both swimming
and bottom-dwelling forms. In many areas, clu-
peoids are important in the diet of the dogfish, but
it undoubtedly feeds on whatever species it can
capture.

In the Pacific Ocean three important studies of
dogfish feeding habits have been made. One such

534

U.S. FISH AND WILDLIFE SERVICE

study was conducted to determine the amount of
predation, if any, by dogfish on salmon smolts as
they descended the Fraser River, British Colum-
bia (Chatvvin and Forrester, 1953). In the river
mouth, 249 dogfish were examined and 20 (8 per-
cent) had empty stomachs. Of those that con-
tained food, 100 percent contained eulachon (a
smelt, Tlutleichthys pacificus), or traces of it, 5
percent contained sand lance, Ammodytes. and 19
percent contained invertebrates, including shrimp,
crabs, small crustaceans, squid, and octopus. A
large number (21 percent) contained sticks and
leaves, no doubt ingested accidentally with the
food items. Outside the river mouth, the dogfish
diet was much the same : 91 percent eulachon, 29
percent invertebrates, and 5 percent sticks and
leaves. Miscellaneous food items included a
honeybee and polychaete worms. On the basis of
their findings the authors concluded the spiny dog-
fish was an opportunistic feeder.

Another study in the same general area was made
by Bonham (1954) who examined more than 1,100
spiny dogfish stomachs, of which nearly 60 per-
cent contained food. He found more than 77 dif-
ferent food items; fish constituted two-thirds of
the diet. The three most common food items were
ratfish, Hydrolagus colliei, (20 percent) ; herring,
Olupea harengus paUasii, (18 percent) ; and krill,
Euphausiidae, (9 percent). The only evidence of
cannibalism was the finding of a 230-mm (new-
born?) dogfish pup in the stomach of a large preg-
nant female. Bonham concluded, "Large and
small dogfish eat much the same kind of food, with
the exception of very small dogfish in whose diet
worms and other mud-inhabiting organisms ap-
pear prominently."

Sato's (1935) studies of the spiny dogfish in the
water around Japan indicate that clupeoids are
important in the diet in this area as they are in
other parts of the world. He examined the stom-
ach contents of 128 dogfish collected in gill and
set nets in June and July. Sixty stomachs con-
tained fish; 48 contained sardines, Sardinops
■s-aga-x melanosticta; and 12 contained other fishes,
including herring, Olupea harengus pallasii, sal-
mon OncorhynckvA keta, and cod, Gadus macroce-
phalus. Invertebrates were found in 21 stomachs.

In waters north of Japan, around Sakhalin.
food items found in the stomachs of spiny dogfish
were noted by Kaganovskaia (1937). The items

were listed simply as herring, iwashi (sardine),
cod, octopus, crab, squid, and sea cucumbers.

Food habits of the dogfish in the North Atlantic
are quite similar to those of the dogfish in the
Pacific. From waters around the British Isles,
Ford (1921) reported food items from 143 spiny
dogfish with recognizable stomach contents.
Fishes were found in 137 stomachs and included
herring and pilchard (67 percent), mackerel (19
percent), and gadids (4 percent). Six stomachs
contained Crustacea, and three had mollusks. The
stomachs were collected at a time when the clupe-
oids and mackerel were abundant and thus readily
available to the dogfish.

In the Northwest Atlantic, around Newfound-
land, capelin, Mallotus villosus, are important in
the diet of the spiny dogfish. Templeman (1944)
made a casual examination of 24 dogfish stomachs
collected in July 1942 and found all of them con-
tained capelin. During this month the capelin
were plentiful on the inshore grounds and the dog-
fish appeared to be feeding almost exclusively on
them. He notes, "Some of the stomachs were full
of capelin, one containing 13 capelin, 1 of 7 cm.
and 12 from 14 to 19 cm. long."

From August to November, Templeman (1944)
made a detailed analysis of 1,171 dogfish stomachs
of which 665 were empty, 367 contained only the
bait used to capture them, and 139 contained food.
In the stomachs that contained food, about 60
percent contained fishes, about 45 percent con-
tained Crustacea, about 8 percent contained coelen-
terates, and a few contained mollusks, polychaetes,
algae, and miscellaneous items. The recognizable
fishes were herring (14 percent), capelin (5 per-
cent), and cod (5 percent).

In the Gulf of Maine, spiny dogfish feed on a
wide variety of species and at one time or another
prey on practically all species smaller than them-
selves. They are regarded as the chief enemy of
the cod, and also feed on mackerel, haddock, her-
ring, squid, worms, shrimps, and crabs. They are
one of the few fishes that eat ctenophores (Bige-
low and Schroeder, 1953)

My own observations of spiny dogfish stomach
contents have revealed a curious condition in which
the stomachs were distended with a clear watery
fluid. Casual observations of 50 dogfish stomachs
collected during a cruise of the research vessel
Delaware in June 1961 on Stellwagen Bank re-

LIFE HISTORY OF SPINY DOGFISH

535

vealed fish remains in only three stomachs. Five
stomachs contained about 4 ounces of a light-gray,
custardlike material, evidently fowl well advanced
in digestion. Most of the stomachs, however, were
filled with clear fluid; only a few stomachs were
empty and flaccid.

Fifty stomachs examined at Pt. Judith, R.I., in
July 1959, contained mostly amphipods {Lepto-
cheirus) and occasional fish remains.

In July 1961, John M. Hoberman found silver
hake (Merbwociua bilinearis) in the stomachs of
dogfish collected in Ipswich Bay during a cruise of
the Delaware. Silver hake were abundant in the
area at the time.

Fishes and rock crabs {Cancer) were the prin-
cipal food items of 33 spiny dogfish collected in
June 1963 off Block Island, R.I. The dogfish were
examined aboard the. research vessel Albatross IV.
Sixty percent contained fish, 33 percent contained
rock crabs, and 7 percent contained squid. Rec-
ognizable food items included squirrel hake,
Vrophycis chuss; silver hake; winter flounder,
Pseudopleuronectes americamis ; and sculpin, My-
oxocephalus sp.

It is evident spiny dogfish have no food pref-
erences, but eat nearly anything that moves. It is
evident too, they are opportunistic feeders, prey-
ing on whatever species are abundant and avail-
able. Their catholic food habits probably con-
tribute greatly to the species' biological success.

AGE AND GROWTH

The traditional techniques used in fishery
biology for age determination are not, unfortu-
nately, applicable to the spiny dogfish. The dog-
fish does not have scales suitable for examination,
and being a cartilaginous fish, it has no true bones
in which visible growth zones are formed. Dog-
lisli otoliths, unlike the calcareous otoliths of the
teleosts, are simply aggregations of sand particles
loosely joined in a gelatinous substance, and thus
offer no opportunity for detection of growth zones.

A possible solution to the problem of determin-
ing the age of the dogfish is presented in an ob-
scure Russian paper (Kaganovskaia, 1933) read
in English translation. Briefly, the paper notes
thai the dorsal spines of t he dogfish are marked
with annulations apparently related to growth
periodicity (tig. 4). The Russian biologisl had
collected the dogfish from the waters around

Sakhalin. At first she examined the vertebrae,
but the barely noticeable rings in them became
even less visible after treatment. Cross sections
of the teeth and of the dorsal spines were ex-
amined, but without success. The teeth showed
no zones, and the spines were found to have an
internal cavity along their entire length. The
enamel coating of the spines, however, had mark-
ings, ". . . which doubtless represent annual
deposits."

Figure 4. — Photograph of a dogfish spine showing the
annulations.

The makeup of the spine is quite similar to the
makeup of a mammalian tooth. Daniel (1934) de-
scribes the structure of the spine as follows :

For almost half its length the spine is buried in the
Integument. The buried part is designated as the root or
base and the exposed portion the crown or spine
proper . . .

. . . The spine contains a large central cavity which
when in place fits over a cartilage of the tin skeleton.
The walls of the spine are made of dentine which in the
crown consists of a double layer. The more superficial
layer is bounded anteriorly and laterally by a layer of
enamel, but enamel does not extend over the posterior
groove which fits up against the basal cartilage of the
fin skeleton. A more or less compact layer of pig-
ment . . . separates the enamel ... in front from the
layer iff dentine.

Kaganovskaia (1933) did not try to validate
the spine markings as year marks although she
noted that the spines of fish less than 1 year old
were light gray in color and had no markings. She
examined a sample of rear dorsal spines (the
posterior spines are more clearly marked than the
anterior spines) from 210 dogfish, 380-1,180 mm.
in length, and reported their ages as "2-25 years.

536

U.S. FISH AND WILDLIFE SERVICE

Her data were presented in a table which I have
incorporated into a growth curve (fig. 5). It
seems reasonable to consider the spiny dogfish a
long-lived species in view of the evidence of tagged
dogfish at liberty for up to 10 years.

. KAGANOVSKAIA (19531
i QONHAM tf ol (1949)

AGE IN YEARS

Figure 5. — Two growth rates for the spiny dogfish, based
on interpretation of spine markings.

Using the Russian method, Bonham et al. ( 1949)
examined the spines from 215 dogfish collected in
State of Washington waters. The fish were 34—127
cm. long and 1-29 years old, and although there is
variation in the Washington data, the trend is
similar to that in the Russian paper. To prepare
the spines for reading, Bonham (personal com-
munication) removed them by slicing down along
the bases of the spines into the back of the dogfish
and freeing the spines from the skin or muscle.
The spines were not treated; and low magnifica-
tion (5X) or none at all was used in actual
examination.

Only about 20 percent of the spines (215 out of
1,100) had markings that were sufficiently dis-
tinct to be readable without appreciable disagree-
ment by different observers (Bonham, personal
communication). In the report (Bonham et al.,
1949) the authors cautioned, "It must be under-
stood that rejection of unclear or doubtful spines
would probably eliminate from consideration most
of the old dogfish, whose spines usually are broken,
badly eroded, and have the annulations closely
crowded near the bases of the spines."

A recent study by Holden and Meadows (1962)
supports the hypothesis of annual zone formation

in dogfish spines. The authors examined the
spines from dogfish landed by trawlers that fished
the grounds around the north and west coasts of
Scotland. A total of 317 males (41.3-82.5 cm.
long) and 445 females (39.6-97.5 cm. long) were
examined. The ages determined were 1-19 years
for males and 1-21 years for females. The rate
of growth for both sexes was about the same up
to the time of sexual maturity (at an age of about
9 years). After the fish became mature, the fe-
males grew faster than the males.

Comparisons between dogfish growth calculated
from spine readings or length frequencies, and
growth observed in tagged dogfish indicate that
the growth of the tagged individuals is often half,
or less, of the calculated values. Bonham et al.
(1949) report that on the basis of a study of eggs
and embryos, the suggested rate of growth is 7 cm.
in 2 years or about 3.5 cm. per year. The rate cal-
culated from spine readings is 3.1 cm. per year, and
from length frequencies 3.3 cm. per year, but from
tagging studies the rate is only 1.4 cm. per year.

In the above example, the spine readings were
from fish 40-100 cm. long (2.5-21 years, indicated
age). An examination of Kaganovskaia's (1933)
data for fish of similar lengths and indicated ages
suggests a growth of 3.5 cm. per year. Temple-
man (1944) calculated ". . . approximately U/fc
cm. as the average growth per year for all mature
females and 1.6 cm. for the first mature year . . ."
However, a tagged dogfish at liberty for 10 years
grew only about 8.1 cm. in that time (Templeman,
1958), but he concludes the fish was in worse con-
dition when recaptured than when tagged, hence
the poor growth rate. Kauffman (1955) reports
the growth of two tagged spiny dogfish from the
Pacific Coast as 14 cm. after 8V2 years at liberty
(2.3 cm./year). A dogfish tagged in British
Columbia waters and at liberty almost 8 years
grew 5% inches (Fisheries Research Board of
Canada, 1952), or about 14.1 cm. (1.8 cm./year).
My own experience with the growth of tagged dog-
fish is limited to one specimen at liberty nearly 1
year during which time it grew only 0.7 cm.

At the present time there is no way to resolve the
differences reported for the annual growth of the
spiny dogfish. No doubt it is a long-lived species,
attaining a maximum age of 25-30 years. The
lengthy time interval between tagging and recap-
ture, up to 10 years for certain individuals, is

LIFE HISTORY OF SPINY DOGFISH

537

perhaps the strongest evidence supporting the re-
ported age determination studies.

LENGTH-WEIGHT RELATION

As with many fishes, female spiny dogfish grow
longer and heavier than the males. Templeman
(1944) reported that the immature females are
slightly heavier than the males at all sizes. Mature
and pregnant females are significantly heavier
than either mature males or immature females.
He presents a length-weight graph and lists the
following lengtlis and average weights for dogfish
from the Newfoundland area:

Length

Weight

Males

Mature
females

Cm.

Pounds
1.7
3.3

4.5

Pounds

Pugsley (1939) reported that Pacific dogfish
females tend to be heavier per unit of length than
males. He includes a length- weight graph that
shows this relation for males, females, and preg-
nant females.

Some length-weight data were collected from
210 dogfish at Point Judith, R.I., as part of a study
of the Southern New England industrial fishery.
These data (sexes combined) were used to calculate
the length-weight relation presented in table 3.

Table 3. — Length-weight relation for spiny dogfish, sexes
combined, Point Judith, R.I., October 1965

Length

Weight

Length

Weight

28...

Cm.

75
90
110
140
180
230
310
390
470
570
680
790

Cm.

31...

40....

2.000

2,560
2.850
3,200

61.... ..

POPULATION STATUS

The total population of the spiny dogfish is not
known, although there is no doubt that it is rela-
tively abundant and may be subject to long-term
Hurt nations in abundance. In the spring of 1846
they were so numerous around Gay Head, Mass.,

that 600 were caught on hooks in 1 day by the crew
of a single boat (Storer, 1867).

Collins (1884) relates an eyewitness report from
a fisherman who observed a school of mackerel at
the surface of Wood Island, Maine, that was being
harried by an immense school of dogfish in August
1880. The fisherman estimated there were about
"100 barrels of dogfish" in the school. The dogfish
surrounded the mackerel ". . . in such a manner
as to inclose the mackerel on all sides and under-
neath, completely preventing their escape."
Many of the mackerel were seen with their tails
bitten off and with wounds in their flanks.

Cod as well as mackerel suffered from the at-
tacks of the dogfish. Earll (1880) considered the
dogfish to be the principal enemy of the cod and
reported that adult cod in the market were seen to
have teeth marks and spine wounds in their flesh,
a result of attacks by dogfish. "The arrival of a
school of dogfish in any locality," Earll noted, "is
the signal for all other species to leave; and in this
way the work of the fisherman is often suddenly
terminated."

Bowers (1906) reported good groundfishing in
Boston Bay in July and August 1903, but in 1904
". . . horned dogfish [were] present in such great
numbers that it was impossible to catch anything
else."

Dogfish were much more numerous in Massa-
chusetts Bay during the last quarter of the 19th
Century and during the early 1900's than they had
been previously, although in the Woods Hole re-
gion they were more plentiful before 1887 than
they have been at any time since (Bigelow and
Schroeder, 1953). These authors felt that per-
haps the period 1904-05 marked a peak in the cycle
of dogfish abundance.

It may be, however, that the population of dog-
fish does not fluctuate greatly but that in their sea-
sonal migrations the main body of fish may visit
one area this year and other areas next year. Our
lack of knowledge about the nature of the popula-
tion (s) makes it difficult to come to any firm con-
clusion regarding the absolute or relative numbers
of fish involved.

As a result of his early studies of the dogfish
around Newfoundland, Templeman (1944) said,
"It is obvious . . . that dogfish migrate rapidly
and for long distances, and since they swim chiefly
in the upper layers of water there are no hinder-

538

U.S. FISH AND WILDLIFE SERVICE

ances to migration such as the contours of the
bottom offer to haddock and cod. Thus, it is quite
possible that the dogfish stocks on the whole eastern
coast of North American mingle sufficiently to con-
stitute a single population."

He modified this somewhat later (1954) after
analyzing his tag return data. "The distant recap-
tures are also numerous enough, considering the
small number tagged, and occur in enough differ-
ent years to show that even if there is not indeed a
single population, there is at least a widespread
intermingling of the populations of adult female
Squabus aoanthias on the Atlantic Coast of North
America."

Exploratory cruise data indicate that, rather
than being distributed relatively homogeneously
over large areas, dogfish congregate in dense, lo-
calized schools. Thus, high concentrations of dog-
fish at a given time and locality provide no
accurate indication of their overall abundance, as
they may be exceedingly scarce a few miles distant.
Large hauls of dogfish tend to be grouped within
a period of a few days, as the vessel fishes the same
general area during the interval. Similarly, con-
secutive tows at different depths may produce no
dogfish at one depth but numerous dogfish at only
slightly greater depths (table 4) .

There is evidence that dogfish may vary in
availability, or abundance, from year to year as
well as from place to place. Data were analyzed
from survey cruises of the research vessels
Albatross III and Delaioare (table 5). The rela-
tive abundance of dogfish, expressed as catch per
30-minute tow, was high in 1948, 1949, and 1950.
Abundance declined markedly in 1955 and 1956
but was moderately high in 1958. In 1959, abun-
dance of spiny dogfish declined once more, but
during 1960-62 it reached a high level nearly on
a par with the peak in 1949. The changes in abun-
dance are also reflected in the commercial catch
of dogfish (see figs. 8 and 9). No explanation
exists for this apparent periodicity in abundance.

POPULATION DYNAMICS

The dynamics of the spiny dogfish population
would be difficult to study now to any fine degree
because much of the necessary information is lack-
ing or is imperfectly known. Perhaps the greatest
gap in our understanding of the species is a knowl-
edge of the nature of the population itself.

Table 4. — Dogfish catches on Albatross III Cruise 126, by
depth, temperature, and sex along Middle Atlantic Coast,
January-February 1959

Transect

Date

Depth

Bottom
tem-
pera-
ture

Males

Fe-
males

Total
fish

Martha's Vineyard

Feb. 3
Feb. 2

Jan. 23
Feb. 1

Jan. 24

Jan. 25
Jan. 26

Meters

116

150

183

268

384

122

168

186

326

417

113

146

289

113

158

213

280

329

119

146

184

229

274

402

131

238

436

141

196

317

•c.

6.6
11.7
10.6
9.4
8.9

7.2
8.9
11.1
10.0
9.4
6.7

Number
48

Number
11

Number
59

14
423

353

367
428

Hudson Canyon

2
10

40
6

2
5

2
10
42
10

7.2
10.6
11.1
11.1

10.0
11.7
11.7
11.1
10.0

53
144

251

138
466

282
717

Delaware Bay -

10.0
12.2
12.2
11.1
11.1
9.4

14
53

66
1
1

119
3

Winterquarter...

10.0
12.2
13.3
11.1

68
4

1
1

59
5
1

8.9
12.2
12.8
12.2
10.0

Table 5. — Spiny dogfish catch on annual survey cruises, all
seasons, all grounds from Nova Scotia to Hudson Canyon,
1948-62

Year

Total tows

Tows with
dogfish

Total
caught

Catch per
tow

1948 ... -

Number
233
115
339
279
93
159
212
117
161
138

Number
57
21
173
64
40
63
38
41
42
37

Number

4,551

3,755

10, 333

672

727

1,923

1,106

2,636

3,799

3,444

Number
19

1949 -- -

1950 -

1955 --

1956

1958 — - -

1959 .

1960

1961

1962 -

The basic plus and minus factors of natality
and mortality lack adequate quantitative investi-
gation. There have been some studies, however, of
certain phases in the reproductive cycle, and these
are discussed below.

REPRODUCTION

Spiny dcgfish are ovoviviparous. The eggs in
the female are fertilized internally by means of the

LIFE HISTORY OF SPINY DOGFISH

539

male's claspers, and the young are born alive. The
period of fetal development is lengthy, perhaps
up to 2 years. The number of young produced at
each delivery by a female dogfish is small.
Sex Ratio

During development in the females, and pre-
sumably at birth, the sex ratio of the pups is very
nearly 1 : 1. Ford (1921) collected 2,720 embryos
at the fish market in Plymouth, England, and
found 1,377 were males and 1,343 were females.
Temple.man (1944) counted 933 males and 931
female embryos in the uteri of 492 females col-
lected in July-November 1942, off St. John's, New-
foundland. For dogfish in the Pacific, Bonham et
al. (1949) report, "Males and females occur in
equal numbers among the embryos." Aasen
(1964b) examined the pups in a sample of 41 fe-
males collected in November 1958 about 100 miles
west of the Orkney Islands. There were 126 males
and 130 females. Our observations for dogfish in
the Gulf of Maine agree with those from other
waters. In July-August 1961 on a cruise of the
Delaware in Ipswich Bay, 234 female dogfish were
examined. Fifty-three contained pups, of which
155 were males and 140 were females.

From the time of birth to the time of attaining
sexual maturity, the young dogfish tend to school
together, but the mature adults tend to school by
sex. Ford (1921) classified the schools, or shoals,
as follows: (1) Shoals of large fish consisting
exclusively of females, the majority in the pregnant
condition; (2) shoals of medium-sized fish exclu-
sively males in the mature condition; (3) shoals
of medium-sized fish of which the majority were
immature females; and (4) shoals of immature
fish in which the males and females were equal in
number.

Sex-size segregated schools are also reported by
Hickling (1930) around Ireland, Temple.man
(1944) off Newfoundland, and Bigelow and Sch-
roeder (1953) in the Gulf of Maine. In the eastern
Pacific, however, Quigley (1928b) observed that
t he schools contained both sexes, and the data listed
by Bonham (1954) for the same general area sup-
port this statement, although in individual catches
the percentage of males varied as much as from
35 to 76 percent. In the western Pacific, however,
Kaganovskaia (1933) observed the schools of dog-
fish to be segregated by sex, size, age, and depth.
She notes, ". . . the shore-set nets caught mainly

immature sharks from 4 to 8 years of age, the bot-
tom-set nets older fish, from 10 to 18 years, mainly
males — (July-October) ; the drift pelagic nets —
chiefly mature females." Thus, her observations
agree in general with those reported from other
parts of the world. I suspect that the dogfish in
the eastern Pacific also school by sex despite the
reports to the contrary by Quigley (1928b) and
the data presented by Bonham (1954) .

On the basis of the reports from areas that in-
clude the known range of the spiny dogfish, it is
difficult, therefore, to determine the sex ratio of the
adults because of the manner in which they school.
Size at Sexual Maturity

Sexual maturity in male dogfish is attained at a
smaller size than in females, and reported studies
indicate that the larger the maximum size of fish
in a population, the larger the size at maturity.
Table 6 lists the data extracted from reports that
specifically mention average size at first maturity
for the spiny dogfish.

Table 6. — Maximum size and size at first maturity of spiny
dogfish from several areas

Locality

Size of males

Size of females

Author

Matu-
rity

Maxi-
mum

Matu-
rity

Maxi-
mum

Ford (1921) ...

Plymouth, Eng-
land.

Cm.

59-60

Cm.
83

Cm.
70-80

70-80
100

74
92

Cm.
110

Hickling (1930)

1 124

(1937).
Templeman (1944)...
Bonham etal. (1949).

Newfoundland

Washington

60
72

100

101
124

' Sex not specified, probably a female.

Because of the age determination problem dis-
cussed earlier, it is difficult to assign an age value
to the time of first maturity. Templeman (1944),
however, suggests that, ". . . it takes the average
female dogfish 9 or 10 years from the fertilized egg
or 7 or 8 years after birth to reach sexual matur-
ity." Based on the spine readings of Bonham et
al. (1949), the data indicate 11 years for males
and 19 to 20 years for females as the age of first
maturity for spiny dogfish in waters off Wash-
ington. Kaganovskaia (1937) did not discover
mature females less than 19 years old or less than
1,000 mm. long. It seems incredible that dogfish
mature at such a late age, but a critical examina-
tion of the evidence offers support for Bonham's
data and Kajmnovskaia's statement.

r,4n

U.S. FISH AND WILDLIFE SERVICE

The reported sizes of spiny dogfish at time of
first maturity are about 72 percent (range 68-80
percent) of the reported maximum sizes for the
species. This is in general agreement with similar
data reported by Bigelow and Schroeder (1953)
for nine species of sharks from the Gulf of Maine
where the sizes at first maturity are about 62 per-
cent (range 52-75 percent) of the maximum sizes.
If we assume (1) that the maximum age (sexes
combined) of the spiny dogfish is 25 to 30 years,
(2) that we can equate length with age, and (3)
that the largest individuals are females, then the
age at first maturity of the females is about 72 per-
cent of the maximum or about 18 to 21 years.

Mating

Although there are no recorded observations of
the actual mating of spiny dogfish and no con-
clusive data to confirm the season of year when it
takes place, the evidence presented by most au-
thorities suggests that mating takes place during
months when the water temperatures are low.
Ford (1921) found newly formed embryos at
Plymouth during November to May. Templeman
(1944) concludes that the eggs are fertilized and
pass into the uteri in February and March, but
more generally in March. He cautions, however,
that his lack of information about the spring tem-
peratures when the eggs are developing may vary
the dates a month in either direction. An exami-
nation of dogfish captured in the Woods Hole area
suggests that ovulation probably occurs in Feb-
ruary or March (Hisaw and Albert, 1947) and
perhaps we can infer that mating and fertilization
of the eggs take place soon after. Bigelow and
Schroeder (1948) believe that in the Atlantic
Ocean, mating probably takes place shortly after
the young are born, although no definite informa-
tion is available.

Reports on mating of the spiny dogfish in the
Pacific Ocean tend to be contradictory, but in gen-
eral support the hypothesis that mating takes place
in the cold months, as in the Atlantic Ocean.
Quigley (1928b) examined slightly over 200 dog-
fish collected in June, July, and August and found
embryos that ranged in size from the smallest to
those with the umbilical scar completely healed and
apparently ready for birth. These observations
suggested that ". . . in the vicinity of Nanaimo,
Squalm sucklli breeds at all times of the year."
We know now, of course, that what she had seen

LIFE HISTORY OF SPINY DOGFISH
795-358 O — 66 2

were the two broods of young that are typical of
the species. Hart (1942) on the other hand, re-
porting the work of Lucus, concluded that breed-
ing takes place during the winter and that,
". . . fertilization by the male takes place soon
after the birth of the young . . ." Bonham et al.
(1949) admitted that the season at which mature
dogfish mate is not known, but regards as a popular
misconception the belief that dogfish breed and
bear young at all times of the year. Sato (1935)
concluded, without much firm basis for the state-
ment, that dogfish breed throughout the year
around Hokkaido.

Fecundity

As might be expected for a live-bearer, the
number of young produced per female spiny
dogfish is small and the period of development
within the mother is long, lasting nearly 2
years. The eggs are large and contain a great
deal of yolk and have been well described by Tem-
pleman ( 1944) . Following fertilization, and dur-
ing early development of the fetus, the eggs (figs.
6 and 7) are contained in a horny capsule ("can-
dle") that later breaks down leaving the embryos
free in the enlarged part of the oviduct (termed
the "uterus"). There is no placental attachment
(Bigelow and Schroeder, 1953) as with some other
species of sharks, but additional material (at least
water) is obtained from the uterine wall (Temple-
man, 1944). The reported number of pups per
female probably should be considered a minimal
figure. The observations were made of fish
caught by otter trawls or other fishing gear and
examined on board the vessel or in the market.
I have seen pups that were apparently near term
prematurely delivered when the females were
landed on the deck of our research vessel. It seems
reasonable to assume that this also happened in
the studies reported in the literature. Fortu-
nately, the number of premature pups was never
very great so that the reported data may be ac-
cepted with a fair degree of confidence.

The greatest number of pups per female was
reported by Kaganovskaia (1937) who recorded 5
to 19, with an average of 11, for the spiny dogfish
near Sakhalin. The least number of pups per
female was reported by Templeman (1944) who
recorded 1 to 7, with an average of 4, for the dog-
fish near Newfoundland. Ford (1921) reported 1
to 11, mostly 2 to 4, from England, while from the

541

Figure 6. — Spiny dogfish egg collected July 1961 in Ipswich Bay. Note the embryo, probably about 4 months old.

West Coast of North America, Quigley (1928b)
reported 3 to 11 (average 7), Clemens and Wilby
(1961) reported 3 to 14, and Bonham est, al. (1949)
reported 2 to 17, mostly 7 to 8. Female spiny dog-
fish collected about 100 miles west of the Orkney
Islands contained 2 to 13 pups, with an average of
6.2 pups per female (Aasen, 1964b).

In the Gulf of Maine, Bigelow and Schroeder
i L953) state that the number of pups per female
may be as many as 8 to 11, or as few as 2, but
mostly 4 to 6. Data collected in July-August
1961, in the inner Gulf of Maine (Ipswich Bay),
show the females may contain from 1 to 11 pups,
mostly 4 to 7.

To examine the relation between the size of
pregnant female and the size and number of pups
Eel use.-) per female, I grouped the data by length
of females by 3-cm. groups (table 7). In addition
to the data for fetuses, the measurements and
numbers of embr3Tos are also included.

Table 7.-

—Fecundity of spiny dogfish examined aboard R/V
Delaware, 1961

Females

wit h
embryos

Embryos

Females
with
fetuses

Fetuses

Length

Average

per
female

Average
length

Average

per
female

Average
length

Cm.

Number
1

Number
5.0

Mm.
4

Number

Mm.

5.0
3.0

5
5

2
6
6

14
9
5
8

4.5
6.0
4.7
3.7
5.6
5.6
7.2
7.9
8.0

154

190

2
6
4
4
1

4.5
4.5
4.2
6.2
9.0

3
9
12

7
6

186

194

197

194

197

205

102

3.0

220

The data suggest that the larger females tend
to have slightly more and slightly larger pups
than the smaller females. This, in general, agrees
with the reports from other parts of the range of
the spiny dogfish. A comparison between the aver-

542

U.S. FISH AND WILDLIFE SERVICE

Figure 7. — Microphotograph of the embryo shown in Figure 6. Actual size of embryo is 19 mm.

age number of embryos per female and the average
number of fetuses per female seems to indicate
there is very little loss (mortality?) between the
two stages of development. The size of the young
dogfish at the time of birth is 20-30 cm., regardless
of the part of the world from which the observa-
tions are reported (table 8) .

Table 8 —

Size of dogfish at birth

Author

Locality

Reported size

of dogfish

pups

Ford (1921)

Plymouth, England _

Cm.
25-31.

Hickling (1930)

About 26.

Kaganovskaia (1933, 1937)

24-31.

Hisaw and Albert (1947)

Bigelow and Schroeder (1918).
Bonham, et al. (1949)

25-30.

22-33.

State of Washington

Average 27.

Aasen (1964b)

Average 26.

Process of Birth

There are two recent instances of spiny dogfish
giving birth to young in tanks at the Bureau's
Woods Hole aquarium. In one instance, I suspect
the female aborted rather than having a normal,
full-term delivery.

The first dogfish was caught with hook and line
October 19, 1962, in water about 27 m. deep. The

surface water temperature was 14.2° C. The fish
was placed in the aquarium the same day, in water
of the same temperature, and apparently adjusted
well to the tank conditions. On November 22,
1962, during the night, she gave birth to three
pups that measured 20.0, 20.3, and 20.7 cm. None
of the pups had any evidence of the yolk sac ex-
cept for a small scar on the ventral surface be-
tween the pectoral fins where the yolk sac had
been attached. Presumably the yolk had been
resorbed and the pups were fully developed. The
water temperature in the tank at the time was 8.4°
C. The pups did not survive, although the mother
continued to live for several weeks until she was
sacrificed.

The second dogfish was collected in a fish trap
and placed in the aquarium on July 24, 1963. The
next day the aquarium attendant observed the de-
livery of two pups. The female was resting
motionless at a slight incline on a pile of rocks in
the tank. Two pups were delivered simultane-
ously, head first, in rhythmical movements that
suggested uterine contractions during mammalian
birth. Delivery of the two pups took about 10
minutes. The female also delivered four more
pups, but the aquarium attendant had been called

LIFE HISTORY OF SPINY DOGFISH

543

away and could not observe the delivery. An hour
later, about 2 cm. of the caudal fin of a pup could
be seen protruding from the female's vent. This
pup was not delivered, and the female died later
in the day. The average length of the pups was
21 cm., and each had a yolk sac attached. Al-
though their size suggests the pups were nearly
full term, presence of the yolk sac indicates they
were still developing. Presumably the female
aborted, perhaps from the shock of capture and
handling or perhaps from the water temperature.
The surface water temperature in the trap was
19.5° C. and the tank temperature was the same.
This is well above the temperature where the
species is commonly found.

When the female was examined, post mortem,
the partially delivered pup was found to be held
by one dorsal spine in the anterior part of the
female's left uterus. The dogfish pup is morpho-
logically suited to head presentation in birth. No
doubt the caudal presentation noted here was ac-
cidental; the rearward sloping dorsal spines —
small as they are — deter smooth, tail-first move-
ment out of the uterus. It is not known if partial
delivery occurs among dogfish in the sea, and none
has been observed aboard our researcli vessels.

Season of Birth

The gestation period of dogfish is nearly 2 years,
although the authorities differ in the exact number
of months involved. Birth generally occurs in the
cold months of the year. Ford's (1921) extensive
studies at Plymouth led him to conclude that gesta-
tion occupies 21-25 months, with the fetuses ready
for birth from August to December. Hickling
(1930) confirmed Ford's findings. Templeman
(1944) suggested a gestation period of almost 24
months with birth between January and May.
Assen's (1964b) data suggest that in the offing of
the Orkney Islands, dogfish pups are ready for
birth in late November or soon after.

A somewhat shorter gestation period for dog-
fish captured in the vicinity of Woods Hole is re-
ported by Hisaw and Albert (1947) who state,
"The gestation period apparently covers about 20
to 22 months and a female gives birth every other
year." The pups, they note, are born in the late
fall, somewhere south of Woods Hole. Bigelow
and Schroeder (1953) report a gestation period of
18 to 22 months with birth probably taking place
on the offshore wintering grounds, although some

may be born in the spring and summer. Latham
(1921) confirmed that some may be born in the
summer when he reported many young dogfish
only a few hours old that were caught in a fish trap
in Long Island Sound in August.

In the Pacific the gestation period is 2 years
with birth taking place during the winter (Hart,
1942), more specifically in November and Decem-
ber (Bonham et al., 1949).

An individual female produces young only in
alternate years (Hart, 1942; Hisaw and Albert,
1947; Bonham et al., 1949; Clemens and Wilby,
1961). The data presented by Ford (1921), Hick-
ling (1930), and Templeman (1944) confirm the
broods-in-alternate-years conclusions of the work-
ers cited above.

MORTALITY

The spiny dogfish has few enemies and is canni-
balistic only to a very small degree. Thus, except
for disease, there is little to act as a deterrent to the
buildup of dogfish populations, and this no doubt
is one of the prime reasons for the vast numbers
of dogfish reported in one area or another. The
predators of the spiny dogfish are mostly the large
sharks and large bony fishes. In table 9, I have
listed the predators as reported in Bigelow and
Schroeder (1953) and noted certain appropriate
remarks. It should be stressed that in all but
twTo of the instances the prey is specifically identi-
fied as the spiny dogfish. The remaining two in-
stances were simply listed as "dogfish" and possi-
bly may be the smooth dogfish.

Table 9. — Predalors of the spiny dogfish

Predator

Mackerel shark (Lamna nasus)

Maneater (CarchaTodon carcharias)

Tiger shark (Galeocerdo cuvier)

Blue shark (Prionace glauca)

Barndoor skate (Raja laevis)

Lancetfish f Alepisaurus ferox)

Tuna (Thunnus thynnus)

Tilefish (Lopholaiilus

chamaeleonticeps) .
Goosefish (Lophius americanus) . . .

Remarks

Known to prey on spiny dogfish in the

eastern Atlantic; probably Gull of

Maine also.
One spiny dogfish, evidently torn off a

line trawl.
Dogfish (species T) from one captured

in Woods Hole.
Preys on spiny dogfish in northern

waters.
Spiny dogfish from Woods nole records.
Small spiny dogfish eaten by Block

Island specimen.
Swallowed whole dogfish (species ?)

weighing 8 pounds.
One contained two spiny dogfish.

One contained a spiny dogfish 1 foot
long and the vertebral columns of 6
others.

Marine mammals apparently are not a threat to
the dogfish. In a study of the food habits of seals
(Fisher and Mackenzie, L955), dogfish remains

544

U.S. FISH AND WILDLIFE SERVICE

were found in the stomach of a grey seal {Hali-
choerus grypus) but constituted only 1 percent of
the volume of the stomach contents. Killer
whales {Grampus orca) may feed on dogfish, but
probably only when other food is unavailable.
One killer whale was seen, "Scavenging round
longlining vessel, eating dogfish." in the Strait of
Belle Isle, July 1953 (Sergeant and Fisher, 1957).
No doubt the relatively large size, spines, and
tough, scabrous skin of the dogfish are effective
deterrents to predation.

UTILIZATION OF THE SPINY DOGFISH

The dogfish is not completely valueless or use-
less. It has some slight value, in limited quantity,
in the United States, and it has greater value in
some parts of the world where it is sought as a food
fish. The greatest value of the dogfish in North
American waters is as an industrial fish for proc-
essing into oil and meal, and at one time it was
under intense exploitation for its liver as a source
of natural vitamin A (fig. 8).

The Bureau of Commerical Fisheries collects
and publishes yearly summaries 3 of U.S. fisheries
by regions. In this paper, data collected from the
Puget Sound, Middle Atlantic, and New England
regions are discussed. The data given in table 10,
and shown in figures 8 and 9, are taken from vari-
ous sections of the statistical reports.

Table 10. — Catch of grayfish ' at principal regions,
1915-61— Continued

Table 10. — Catch of grayfish ' at

principal regions, 1915-61

Year

New England
States

Middle Atlantic
States

Puget Sound, Wash.

Catch

Value

Catch

Value

Catch

Value

Pounds

Dollars

Pounds

Dollars

Pounds
7, 093, 996

Dollars
15,959

1919
1922

63,667

184

6,359
53,400
97,005
41,549
290, 395
89, 707
3,203
286, 419
371, 180
778, 560

1923

21,950

367

247

1925

1926

6,755

347

1,452

1927

449

206, 309
213, 306
93, 196
44,330
27, 049
13, 428

3,312

2,829

3,049

454

374

151

1929
1930
1931
1932
1933

38,605
12,690
4,796
8,140
6,739

552
267
90
81
135

1,060
1,309
2,335

1935
1936

35,300

733

115,500

2,053

277, 500

330, 700

1, 620, 100

578, 100

2, 365, 200

3, 341, 100

23, 532, 300

527
764

1937
1938

1939

1940
1941=

31,600
46,200
85,700
575, 500
575, 500

578
1,111
1,124
19. 426
19,426

57,700
102, 200
47,800
51,800
51,800

545

1,021

478

1,009

14,360

4,153

17,738

36,504

751, 620

See footnotes at end of table.

New England

Middle Atlantic

Puget Sound, Wash.

States

Year

Catch

Value

Catch

Value

Catch

Value

Dollars

Pounds

Dollars

Pounds

Dollars

1942

127,300
47,300

3,802
1,959

16, 932, 400
22, 021, 500

liti.H, SHI

1943

89,700

1,637

1, 243, 858

1944

53,300

1,446

6,600

200

39, 513, 700

2, 094, 217

1945

31.100

565

31,000

1,211

22, 149, 100

1, 063, 149

1946

107, 600

2,472

54,200

3,327

20, 991, 800

1, 366. 513

1947

24,000

455

21,200

1,046

14, 984, 800

954.535

1948.

55,100

775

3,000

150

12, 302, 700

711, 125

1949

625,200

5,718

55,500

2,163

10, 587, 000

447, 828

1950

111,200

1,171

37,200

1,829

1, 914, 600

33, 197

1951

39,600

539

63,700

3,051

2, 412, 900

58,750

1952 ..

11,200

254

42,700

1,857

2, 981, 400

47,535

1953

9,000

<500

65,000

3,000

2, 225, 600

17,669

1954

2,000

<500

61,000

3,000

2, 008, 800

19, 931

1955

7,000

<500

86,000

3,000

1,935,300

14,029

1956

486, 000

4,000

60,000

2,000

1, 526, 400

12,808

1957

1,287,000

10,000

55,000

2,000

1, 860, 900

33, 390

1958

893,000

8,000

50,000

1,000

4, 233, 100

26, 675

1959

763,000

6,000

71,000

3,000

3, 091, 900

28,189

1960

1, 006, 000

7.000

52,000

2,000

1 1,378,400

6,931

1961

970,000

6,000

70,000

3,000

790, 700

3,953

i Grayfish is the market name for dogfish. .

2 No survey on east coast. Data reported were those collected in 1940.

' Fishery statistics of the United States. 1919-63, U.S. Depart-
ment of the Interior, Fish and Wildlife Service, and predecessor
agencies.

Figure 8. — Dogfish catch from Puget Sound, Wash.,
1915-61.

LIFE HISTORY OF SPINY DOGFISH

545

The fishery for dogfish on the west coast of the
United States has been studied by Alverson and
Stansby (1963), who discussed the technological
developments in the use of dogfish and some
methods for control of the extensive populations.
They reviewed the fishery and its effects on the
abundance of the dogfish and recommended that
an economic use be developed for the. dogfish and
that research be instituted to determine the bio-
logical effects of control of the species.

The possible uses of dogfish are the subject of
an extensive review by Osterhaug (1961), who
included a bibliography of 166 references on the
subject. The first part of the review discusses
the significance of the urea content of dogfish
flesh. The second part discusses possible uses in-
cluding animal feeds, particularly for ruminants
that are able to utilize urea in their diets.

The fishery for dogfish on the east coast of the
United States was never as intensive, nor did it
ever reach the heights reported for the fishery on
the west coast. However, from time to time the
east coast fishery was active for oil, guano, meal,
and human food (fig. 9) . Details of the fishery are
outlined below.

New Engiond States
Middle Atlantic Sto

Figure 9. — Dogfish catch from the New England and
Middle Atlantic States, 1919-61.

INDUSTRIAL USES

One of the earliest mentions of an industrial
use for dogfish was made by Perley (1852), who
reported on the species in the Gulf of St. Law-
rence. He noted that the skins were used by cabi-
net makers to polish hardwood, the livers were
used for oil, and the carcasses were dried and fed

as a winter food supplement to cattle. Pigs in
particular were said to thrive on this diet.
Reduction for Oil and Meal

A fishery for dogfish existed around Province-
town, Mass., during the late 19th century and was
prosecuted with handlines baited with silver hake
(Storer, 1867). The fishery took place in Sep-
tember through November when the dogfish ap-
peared in the area during their seasonal migra-
tion. Only the livers were wanted for their oil —
one thousand livers yielded one barrel of oil —
and the oil was sold to tanners and curriers for
preparing and treating leather.

In other places, the whole dogfish was used for
reduction, especially when more desirable species
such as menhaden were less abundant. A men-
haden reduction plant in East Boothbay, Maine,
processed dogfish for oil and guano (Gallup,
1883). The fishermen were paid $1 per 100 fish,
but it was suggested that the Federal government
pay a subsidy to encourage greater fishing effort.
Spiny dogfish was the principal species used for
oil and guano when a guano factory was estab-
lished at Woods Hole (Smith, 1898), but a scar-
city of the species in the season of 1897, and the
general irregularity of their supply, caused the
factory to turn to menhaden for raw material.

Many early writers tried to stimulate utilization
of the dogfish by citing the different ways the fish
could be used. I. Field (1907) mentions that dog-
fish oil (liver oil?) was used for illumination in
some areas and that on Cape Cod the carcasses
were dried and used for fuel. G. Field (1912)
reports that on Cape Breton Island dogfish were
dried on fences and fed to horses as a diet supple-
ment and the well-yolked eggs were used experi-
mentally as a substitute for hen's eggs to tan
leather.

Barraclough (1953) cites interesting historical
information about the early uses and develop-
ments of dogfish oils in and around the coastal
areas of British Columbia. The local Indians
processed the livers and used the oil obtained for
dressing skins and hides. Later, as lumbering
operations began in the area, the oils were used to
lubricate skidways on logging roads. The oil was
used extensively for lubrication and illumination
in sawmills, coal mines, and coastal lighthouses.
Most of the oil was processed in small home-type
operations, but in 1877 the first large commercial

546

U.S. FISH AND WILDLIFE SERVICE

factory was established for oil production. It is
worth noting here that during the time of World
War I (1916-18) almost the entire catch of dog-
fish from British Columbia was exported as
"grayfish" to the U.S. fresh fish market.
Extraction of Vitamin A

No doubt the greatest industrial use of the dog-
fish took place about 1937-47 when the species was
fished intensively in Puget Sound and surround-
ing waters. Their rich, oily livers were in demand
as a valuable source of natural vitamin A. The
livers contain 50-75 percent oil, and the vitamin
A content of the oil is 5,000 to 30,000 U.S. Phar-
macopeia (U.S. P.) units per gram (Harrison and
Samson, 1942).

The first extraction of vitamin A from shark
liver oil was begun on a commercial scale about
1936-37, and the dogfish fishery was underway in
Puget Sound in 1937-38 (Harrison and Samson,
1942). The fishery was on a small scale until
about 1940, then, with the entry of the United
States in World War II and the loss of foreign
sources of vitamin A from cod liver oil, the fishery
increased in intensity. In 1940 the average price
paid to the fishermen for the livers was 5.7 cents
per pound, but by 1943 the average price was 46
cents per pound and at one point reached a high
of 54 cents (Bonham et al., 1949). The intensity
of the fishery undoubtedly had a marked effect on
the size of the dogfish population. Barraclough
(1953) reports a decline in availability of the
species in Hecate Strait beginning in 1944.

Dogfish liver oil has high vitamin A potency.
Bonham et al. (1949) note that oil rendered com-
mercially from livers of dogfish taken in the
waters in and around Washington varies from
5,000 to 25,000 U.S.P. units of vitamin A per
gram. The vitamin values increase several hun-
dred percent when the fish attain sexual maturity,
and the content is greater in winter than in other
seasons. In contrast, Templeman's (1944) lab-
oratory extractions of vitamin A from Canadian
dogfish liver oil ranged from 300 to 19,700 U.S.P.
units per gram with an average value for imma-
ture females of 1,183 units, for mature males of
1,662 units, and for mature females of 2,780 units.
(For purposes of comparison, pharmaceutical cod
liver oil must contain not less than 850 U.S.P.
units of vitamin A per gram (Bailey, 1952).)
Hirao, Yamada, and Kikuchi (1959) report vita-

min A values of spiny dogfish flesh from 329 to
5,220 U.S.P. units per 100 grams of flesh. Liver
oil from the same fish contained from 2,080 to
38,800 U.S.P. units of vitamin A per gram.

Following the end of World War II, two major
events occurred that had a devastating effect on
the west coast fishery for dogfish. First, foreign
sources of vitamin-rich fish oils again became
available, and second, vitamin A was synthesized
in 1947. Soon after this the dogfish fishery col-
lapsed except for relatively small volumes landed
for reduction and an extremely limited food
market.

During World War II the Canadian govern-
ment became interested in the east coast dogfish
liver oils and their vitamin content, but the prices
paid to the fishermen were too low to develop a
fishery (Tern pieman, 1944).

Oils obtained from dogfish are of value today
chiefly as raw materials for other industrial proc-
esses. The liver oil is sulfurized and used as a
rubber extender, and the body oils are used in the
tanning of leather (Bailey, 1952).
New England Industrial Fishery

The late 1940's saw the beginning of a new kind
of fishery in New England — the so-called trash
or industrial fishery — in which nonfood species,
including spiny dogfish, were landed in great
quantities for reduction to meal and oil. Sayles
(1951) marks 1948 as the start of the trash fishery
at southern New England ports with the processed
meal destined for use as supplements in hog and
poultry feeds.

The amount of dogfish used was small at the
start of the industry. For example, the species
composition of a sample from one boat that
landed at New Bedford in October 1949 included
only 1 dogfish in the sample of 536 fishes (Snow,
1950), but by 1956, 259,000 pounds of spiny dog-
fish were landed by the industrial fleet at New
Bedford (Edwards and Lux, 1958). The dogfish
represented 1 percent of the total industrial land-
ings and were caught off No Mans Land, mostly
in November and December.

In 1957 the Southern New England industrial
landings of spiny dogfish were slightly more than
5 million pounds (3 percent of the total), with
most of them landed at Point Judith, R.I.
(Edwards, 1958a). There were two peaks in the
landings of dogfish, one in the spring and one in

LIFE HISTORY OF SPINY DOGFISH

547

the fall, no doubt representing periods when they
were locally abundant during their migrations.
The industrial fishery fleet at Gloucester caught
quantities of dogfish off Cape Ann, Mass., on
Stellwagen Bank, and off Nauset, Mass., although
the volume landed represented only from 1.5 to
3 percent of the total pounds landed (Edwards,
1958b).

Reduction plants do not like to process large
amounts of spiny dogfish because they yield only
meal, with very little oil, and there are serious
mechanical problems involved in handling the
species. The rough skin of the dogfish causes
these fish to jam conveyor belts, and to pack in
bins and chutes. The collagen in the carcasses
clogs screens (Tarr, 1958). Tarr also states that
the dogfish result in a poor yield of meal com-
pared to other fishes.

Change in the design of processing machinery
is suggested as one way to overcome the problems
in handling dogfish carcasses. For example, in-
stallation of grinders designed specifically for
dogfish may solve the jamming problem, but fur-
ther technological research is needed before dog-
fish carcasses can profitably be used (Alverson
and Stansby, 1963).

The rapidly expanding pet-food industry has
been suggested as a potential user of great quanti-
ties of dogfish. Jones (1959) reports that on the
Pacific coast the estimated potential annual pro-
duction of dogfish for dog and cat food is on the
order of 60 to 80 million pounds.

FOOD USES

A vast protein food resource is wasted each year
in the 'United States because only infinitely small
amounts of spiny dogfish are used for human food.
Under present economic conditions, however, and
because of prejudice toward eating shark flesh, it
probably would be most unprofitable to fish and
market dogfish for human food.

The repugnance (and perhaps fear) that most
people feel towards sharks in particular does not
help to make dogfish popular as a food fish. The
rery name "dogfish" connotes something not suit-
able for humans. Efforts to disguise the species
under a euphemism have included simply not
mentioning what it was. Thus, Field (1907) re-
ports it was served as "fish" on two occasions in
the Marine Biological Laboratory (Woods Hole)

mess hall and enthusiastically accepted by the un-
suspecting diners. It has been served experi-
mentally in hotels and listed on the menu as "Jap-
anese halibut." In England, dogfish are gutted,
skinned, beheaded, and marketed as "flake" and
"rock salmon" and are widely used as one of the
ingredients in the popular carryout dish, fish-and-
chips.

In the United States during World War I, a
great effort was made to popularize a number of
relatively unexploited fishes to increase their ac-
ceptance by the consumer and thus relieve the
war-induced meat shortage. Spiny dogfish was
one such fish, and it was dubbed "grayfish," the
name by which it is marketed today. A 14-ounce
can of grayfish sold retail for 10 cents, and a
Government circular (U.S. Bureau of Fisheries,
1916) was published in which 17 different recipes
for preparing grayfish were listed.

Canned grayfish did not prove to be a practical
solution to the problem of dogfish utilization.
Corrosion of the cans, caused by changes in the
chemistry of the meat, and the offensive ammonia
smell that developed caused the buying public to
reject the product. The flesh of dogfish, as with
other elasmobranchs, contains large amounts of
urea, which rapidly decomposes to form ammonia
(Mavor, 1921). Fresh and frozen dogfish tissue
contain about the same amounts of urea (0.9-
1.5 percent), and hydrolysis, with the subse-
quent release of ammonia, occurs in the frozen
flesh (Benson, 1924). Moyer, Southcott, Baker,
and Tarr (1959) tested several methods of storing
fresh dogfish flesh for periods up to 21 days. The
storage included in ice and in refrigerated sea
water, with and without added antibiotics (chlo-
rotetracycline). They concluded, ". . . dogfish,
when stored under nearly ideal conditions, appear
to spoil no more rapidly than most other sea fish."
It seems obvious though that dogfish is best eaten
when very fresh.

The keeping quality of dressed dogfish was fur-
ther studied by Southcott, Moyer, Baker, and Tarr
(1960). The fish were stored in individual poly-
ethylene bags at 0°, 5°, and 10° C, with a control
lot unbagged in crushed ice. The experiment
lasted 21 days. Each day two fillets were cut from
a single fish from each treatment and used for
bacteriological and chemical determinations.
The authors found that, "Less ammonia and

548

U.S. FISH AND WILDLIFE SERVICE

trimethylamine were produced in iced fish samples
than in bagged fish samples at 0° C, although
bacterial counts in the two treatments were com-
parable." They suspected, however, that the melt
water from the ice leached some of the chemical
products from the flesh. Bacterial and chemical
values rose rapidly at 5° C. and 10° C, and these
treatments were ended at 17 days and 8 days, re-
spectively. In general, pronounced ammonia
odors were noted in only a few samples, and these
were "strongly masked" by putrid odors.

Dogfish flesh is quite palatable and may be pre-
pared in a variety of ways. My family and I
have eaten fried dogfish fillets and enjoyed the
meal. The fillets are easily cut from the fish and
easily skinned. The meat is bone-free and white
and has a flaky consistency and firmness similar
to haddock fillets. The flavor is mild, and the
frying produced no odors other than would be ex-
pected with any fish.

Dogfish fillets were prepared in several different
ways and eaten by a test panel at the University of
Washington in 1959 (Liston, 1960) . The steamed
fillets were rated very good and brined and smoked
dogfish was well accepted. In a comparison be-
tween fishsticks made with dogfish and two brands
of fishsticks bought in a retail store, those made
with dogfish were rated as first or second prefer-
ence by all panel members.

Dogfish is popular in Europe today as a food
fish, not only in England but also in Continental
Europe. In 1960, 25,600 metric tons, worth nearly
11 million kroner (1 krone is about (U.S.) 14
cents), were landed by Norwegian fishermen and
shipped to England (Food and Agriculture Or-
ganization of the United Nations, 1961). It is
marketed both in steak and fillet form.

A small but steady market for dogfish (listed as
grayfish) exists in New York's Fulton Fish
Market where it has an ex-vessel value of 3-^ cents
per pound but has gone as high as 8-10 cents per
pound.4 The fish are mostly incidental to otter
trawl catches of other food fishes. The dogfish
are gutted, skinned, and cut into small pieces, and
sold at retail mostly to buyers of southern
European extraction (Italians, Portuguese,
Greeks), Chinese, and Negroes. Some retailers

* Ledner, J. F., 1964. Fishery products report, N-252, Dec.
29. 1964. U.S. Bureau of Commercial Fisheries, Market News
Service, New York, N.Y., 4 pp. [Unpublished processed report.]

fry the pieces to order for "fish and chips."
(Farther south on the Atlantic coast, in the
Chesapeake States, the species sold as grayfish is
the smooth dogfish.)

MANAGEMENT OF THE SPECIES

The problem of the spiny dogfish as a pest of
the commercial fishermen has led to a search for
some method to control the species and at least
reduce their numbers to the point where they
would no longer constitute a problem. Many
ideas have been advanced — some quite fanciful —
including the usual solution to such pest problems,
the payment of bounties for their capture. Un-
fortunately, most of the schemes suffer from a
lack of, or incomplete, knowledge of the life his-
tory and habits of the dogfish.

Some of the earlier control methods proposed
were based on methods used to control terrestrial
pests. Atkins (1904) recounts a few suggestions
offered by the public as to how the dogfish problem
might be handled. Among these are the follow-
ing: (1) Attach streamers, bells, chains, etc. to
hundreds of dogfish and release them to frighten
off the school (like belling a rat in a pack) ; (2)
inoculate some of the dogfish with a fatal disease
organism, such as had been done with rabbits in
Austrialia; (3) dynamite the dogfish schools
when they appear; (4) employ Government boats
and men to capture the dogfish, until the plague is
reduced; (5) pay a bounty to fishermen for
capturing the dogfish; and (6) use long seines of
strong cord, 41,000 yards or more in length, and
surround the schools as is done with the schools
of sharks in India.

The best control method, however, would be
greater utilization of the dogfish, particularly as
human food. Or, as Atkins stated it: let the
public ". . . apply their teeth and eat the dogfish
up."

Increased use of the species, particularly indus-
trial utilization, carried out over a period of years,
would undoubtedly reduce the numbers and keep
them at a relatively low level. There is evidence
that short-term programs designed to reduce the
dogfish population, particularly if carried out in
local areas, are not successful. Templeman (1944)
notes, "In Placentia Bay alone during the 1938
attempt to reduce dogfish numbers, about 10,391,-
000 pounds of dogfish were caught or approx-

LIFE HISTORY OF SPINY DOGFISH

549

imately 2 or 3 million fish without any apparent
diminution of the supply."

The results of increased exploitation of the
North European oceanic stock of dogfish are dis-
cussed by Aasen (1961, 1963, 1964a, 1964b). In
the period 1957-62, the Norwegian catch of dog-
fish increased by 50 percent. Returns from dog-
fish tagged in 1958-60 indicated an annual fishing
mortality rate of 7 percent and an annual natural
mortality rate of 20 percent.

During the 1961-62 fishing season, there was
an annual mortality rate of 38 percent, (Aasen
did not separate fishing and natural mortality.)
And he reported (1964a) an average total instan-
taneous mortality rate of 72 percent in the years
1960-63. He interpreted the high figure as a
"danger signal." A measure of catch per unit of
effort for the period 1957-63 ". . . shows a heavily
declining stock [of spiny dogfish]."

The evidence presented by Aasen in his several
papers, and by Barraclough (1953), shows that
long-term exploitation of the dogfish can produce
a real reduction in their numbers. Thus, increased
fishing effort, on the dogfish off the United States
could bring about some marked changes in the size
of the population. It is not unreasonable to sus-
pect that future fishery biologists might be called
on for studies to save declining dogfish stocks in
North American coastal waters.

If increased use of the dogfish is not feasible,
either for food or industrial purposes, some other
method of control should be investigated. A rather
unique method — the sterile-male technique — has
been used successfully to control the screw-
worm, an insect pest of cattle, and may prove of
some Value in the case of the spiny dogfish. The
method is described by Knipling (1959) and,
briefly, involves sterilizing laboratory-reared male
screwworms through the use of gamma irradia-
tion. The treated males are released in the area
of infestation in the ratio of 5 to 10 times the num-
ber of normal males. Females that mate with the
sterile males lay infertile eggs, thus reproduction
is greatly reduced. The treatment has been suc-
cessful in eliminating the pest on the island of
Curacao and controlling it in Florida. Knipling
states that this control method is based on the
following biological principle: "The introduction
of sexually sterile but otherwise sexually vigorous
males, and to a lesser extent females, into the

natural population of an animal species will have
greater influence in reducing the biotic potential
of the population than elimination of the same
number of individuals from the same population
by destruction or removal." The sterilization
could be done either by irradiation or with
chemicals.

It would be difficult at the present time to try to
evaluate on a theoretical basis the sterile-male tech-
nique applied to the spiny dogfish problem. We
lack some very necessary knowledge of the life his-
tory of the species. For example : ( 1 ) How many
dogfish need to be sterilized to effect control (that
is, how many dogfish are present in the total popu-
lation), (2) how many times in its lifespan will
a dogfish mate (screwworms mate once), and (3)
does one male dogfish mate with more than one
female in a given season?

The low fecundity of the spiny dogfish and the
long period of gestation are factors very much in
the favor of any control method that might be
applied. But mere control is not a very satisfy-
ing solution to the problem of dogfish abundance.
From a conservation standpoint it would be more
desirable, of course, to find a use for what is very
obviously a rich potential resource. It is possible
that in future years, when additional sources of
animal protein are needed for human food, we
may see development of an active fishery for the
species. Such a development would then remove
the dogfish from the pest classification.

SUMMARY

The spiny dogfish, SquaJus acanthias, is a small
shark of the family Squalidae. It is extremely
abundant locally and seasonally and has proved to
be a costly nuisance to commercial fishermen in the
United States.

It grows to a maximum length of 100-124 cm.
and a maximum weight of 7.3-9.8 kg. The fe-
males usually are slightly larger than the males.
Two sharp spines, one anterior to each dorsal fin,
are the features that give the species its common
name and serve to separate it readily from the
smooth dogfish, Mustel/us en nix.

Although the spiny dogfish is distributed in
many parts of the world, this report deals mostly
with the groups found in the Northwest Atlantic.
Pertinent information, however, is reported from
studies of the species made in other areas.

550

r/.S. FISH AND WILDLIFE SERVICE

The spiny dogfish usually is found in large
schools composed of: (1) large, mature females;
(2) medium-size-fish, either mature males or imma-
ture females; or (3) small, immature fish of both
sexes in about equal numbers. The schools may
spend considerable time in an area and then move
rapidly from one area to another.

In the Northwest Atlantic they move from the
southern part of their range, off North Carolina
to New York, northward with the advance of the
spring season. It is suspected they spend the win-
ter offshore in deep water. In addition to the
seasonal migrations, spiny dogfish take part in a
daily migration, rising to or near the surface dur-
ing the night and returning to the bottom during
the day.

Tagging studies have had low rates of return
compared with tagging studies of commercially
valuable fishes. But the returns have shown that
the spiny dogfish is capable of long-distance migra-
tions— one individual travelled 4,700 miles — and
is long-lived since several tagged fish were at lib-
erty 7 to 10 years. In the New England area, the
recaptures suggest that spiny dogfish school to-
gether for long periods of time and return to the
same general area at about the same time of year.

Food habits studies show that spiny dogfish are
primarily fish eaters but also feed on invertebrates,
both swimming and bottom-dwelling forms. Clu-
peoids, smelts, and chimeroids were the fishes
found most frequently in dogfish stomachs. They
also feed on shrimp, crabs, and squids and are one
of the few fishes that eat ctenophores. In gen-
eral, they are considered opportunistic feeders,
preying on whatever is abundant and readily
available to them.

Age and growth studies based on interpreta-
tion of annulations on the dorsal spines suggest
the spiny dogfish is long-lived with some individu-
als attaining ages of 20 to 30 years. Based on the
spine readings, the growth rate is about 3% cm.
per year. Growth of tagged dogfish, however, is
less, usually about 1% cm. per year. At a given
length, female dogfish are slightly heavier than
male dogfish; mature and pregnant females are
the heaviest and longest individuals.

It is difficult to make any. analyses of the dynam-
ics of dogfish populations because so much of the
basic life history information is lacking. More is

known about the natality of the species than about
the mortality.

The spiny dogfish is ovoviviparous. Sex ratio
of the developing fetuses is very nearly 1 : 1, and
presumably the young are born in the same ratio.
Sex ratio of the older fish varies with the sexual
maturity of the individuals; in general they tend
to group themselves by sex. Sexual maturity is
attained by males at 80-100 cm. in length and by
females at 100-124 cm.

Mating takes place during the cold months,
probably on the wintering grounds, and the young
are born after a 2-year development. The num-
ber of young born per female varies with location.
In the Pacific it averages about 11 in the western
part and about 7 in the eastern part. In the
Atlantic it averages about 4 in the western part
and about 3 in the eastern part. At the time of
birth the young dogfish are about 20-30 cm. long.

The natural mortality of the adults apparently
is low. In the Western Atlantic their principal
predators are the large sharks and large bony
fishes. Records of cannibalism are rare, and there
are few records of marine mammals feeding on
spiny dogfish. Fishing mortality, however, takes
a relatively high toll.

In the United States the spiny dogfish has been
exploited mostly as an industrial fish for reduc-
tion to meal and oil. Immediately preceding and
during World War II, the groups on the west coast
were heavily exploited for their livers, an impor-
tant source of natural vitamin A. At the peak of
the fishery, in 1944, more than 40 million pounds
of dogfish were taken from Puget Sound. The
fishery collapsed when vitamin A was synthesized
in 1947, and today about 2 million pounds are
landed yearly. Most dogfish are caught with ot-
ter trawls or gill nets.

There is a small and relatively steady market in
the United States for dogfish as human food.
Technological problems, however, have prevented
it from becoming more than just locally popular.
Fresh dogfish fillets have a flavor and texture
somewhat resembling those of haddock. It is a
popular food fish in parts of Europe.

Management of the species is indicated to re-
duce the damage it causes to more valuable com-
mercial fisheries. Finding an economically at-
tractive use for the dogfish would be the most
worthwhile management method. Lacking this,

LIFE HISTORY OF SPINY DOGFISH

551

perhaps some form of biological control must be
instituted. However, more detailed information
is needed about the life history and biology of the
spiny dogfish before any management plan can be
drawn up.

ACKNOWLEDGMENTS

Robert L. Edwards contributed many valuable
observations on the dogfish in the Southern New
England industrial fishery. Raymond L. Fritz
collected specimens and made many of the obser-
vations at sea.

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554

U.S. FISH AND WILDLIFE SERVICE

PYGMY WHITEFISH PROSOPIUM COULTERI IN THE NAKNEK RIVER

SYSTEM OF SOUTHWEST ALASKA

By William R. Heard and Wilbur L. Hartman, Fishery Biologists (Research)
Bureau of Commercial Fisheries Biological Laboratory, Auke Bay, Alaska

ABSTRACT

The pygmy whitefish is widely distributed through-
out the lakes of the Naknek River system in southwest
Alaska. It is a small abundant species in some lakes
of the system and may occupy a more prominent place
in the population dynamics of fishes in the Naknek
system than in other geographic areas where it has been
studied. Specimens were collected with a variety of
sampling gear including gill nets, tow nets, otter trawls,
and seines. Pygmy whitefish occurred in all benthic
habitats from shallow littoral depths to bathybenthic
areas. Seasonally in certain age groups and in certain
areas they occurred in limnetic areas of lakes and in
streams. In the Naknek system, 18 species, including
the young of commercially valuable sockeye salmon
and the closely related round whitefish, were ecological
associates of pygmy whitefish.

Two populations, one in South Bay of Naknek Lake
and the other in Brooks Lake, were studied in detail.
The oldest and largest pygmy whitefish collected was
an age V 163-mm. female from South Bay. An age III
83-mm. female was the oldest and longest specimen
from Brooks Lake. Length frequency distributions
from other lakes were intermediate between these
extremes. Growth rates were back calculated from
polynomial body length-scale length equations for
Brooks Lake and South Bay populations.

Dipteran insects were the principal foods eaten by
pygmy whitefish in South Bay. Crustacean plankton
dominated their diet in Brooks Lake. In other areas
insects and zooplankton were about equal in impor-
tance. Growth and insect consumption were correlated
positively.

Spawning occurs in November and December, appar-
ently only at night. South Bay fish spawn in lower
Brooks River. Eggs in ripe females from South Bay
averaged 2.4 mm. in diameter, and the ovaries were
16.5 percent of the body weight. The fork length-
fecundity relation of Naknek system pygmy whitefish
has the equation

Log E= -2.9552 + 2.7513 Log L

Both sexes mature earlier in Brooks Lake than in
South Bay.

Slow growth, low fecundity, and short life character-
ize pygmy whitefish in Brooks Lake. These factors
are compensated for in part by early maturity and
probably by a low mortality from fertilized egg to
maturity. The wide range of pygmy whitefish popu-
lations in the Naknek system probably reflects adaptive
responses of a highly plastic species to the wide variety
of environmental characteristics found in different
lakes of the system.

Pygmy whitefish, Prosopiwm coulteri (Eigen-
mann and Eigenmann), are widely distributed
throughout lakes of the Naknek River system in
southwest Alaska (fig. 1). These lakes, which are
important fresh-water rearing areas for juvenile
sockeye salmon, Orworhynchus nerka (Walbaum),
are studied by the Bureau of Commercial Fish-

Note. — Approved for publication March 4, 1965.

eries to determine factors limiting fresh- water pro-
duction of this highly important commercial spe-
cies. These studies embrace a variety of limnolog-
ical and biological research, including interspecific
relations of fishes associated with juvenile salmon.
Pygmy whitefish are apparently the most ab-
undant species in some lakes of the Naknek system,
and it is possible that they may compete directly

FISHERY BULLETIN: VOLUME 65, NO. 3

555

IDAVAIN LAKE-

<«,

COVILLE-
LAKE

**A

ff,

NAKNEK LAKE

WEST
END

SOU?,

!?S>

NORTH

ARM

BROOKS RIVER-

GROSVENOR RIVER

BROOKS LAKE

.**

,0*'

RIVER

ILIUK ARM-

—i —

—i—

MILES

• LOCALITY RECORDS

O AREAS WHERE PRINCIPAL COLLECTIONS WERE MADE

Figure 1. — Naknek River system of southwest Alaska, showing areas where pygmy whitefish were collected. Dots
represent locality records ; circled numbers are locations where 10 or more pygmy whitefish were collected in a
specific sampling effort.

or indirectly with juvenile sockeye salmon for food
or space. Other fishes, for instance the threespine
stickleback (Gasterosteus aculeatus) , have also
been characterized as actual or potential competi-
tors with juvenile sockeye salmon (Krogius and
Krokhin, 1948; Greenbank and Nelson, 1959; and
Burgner, 1960). Pygmy whitefish may also act
as a buffer between salmon predators and young
salmon.

There is relatively little literature concerning
pygmy whitefish, and specific studies on the biol-
ogy of this species are few. They were discovered
in British Columbia in 1892 and were first col-
lected in Alaskan waters in 1912 (Kendall, 1917).
Although locality and life history data accumu-
lated for several years (Snyder, 1917; Kendall,
1921; Schultz, 1941; and Wynne-Edwards, 1947

and 1952), published material was based on few
specimens. Meyers (1932) reported on 21 speci-
mens from Chignik Kiver on the Alaska Pen-
insula, and Weisel and Dillon (1954) reported on
23 pygmy whitefish from western Montana. Esch-
meyer and Bailey (1955) collected 1,623 pygmy
whitefish from Lake Superior during a 2-year
study and reported the discovery of a relatively
large population in the lake and described its
morphology and life history. Comparisons were
made with previous collections from the Pacific
slope. McCart (1963) has recently studied the
growth and morphology of pygmy whitefish from
several British Columbia lakes.

Pygmy whitefish were first collected in the Nak-
nek River system at Brooks Lake in 1957, and ob-
servations in Brooks Lake have continued since

556

U.S. FISH AND WILDLIFE SERVICE

then.1 Beginning in 1961 and continuing through
1963, observations were extended throughout the
Naknek system. More than 10,000 specimens have
been collected by various methods since 1961.

The present study was undertaken to investigate
the distribution, age and growth, food habits, re-
production, and general life history of pygmy
whitefish in the Naknek system. Emphasis was
placed on determining the relation of pygmy white-
fish biology to that of other fishes in the system,
particularly the sockeye salmon.

STUDY AREA

The Naknek River system, much of which lies
within Katmai National Monument, consists of
seven interconnecting lakes : Hammersly, Murray,
Coville, Grosvenor, Brooks, Idavain, and Naknek.
These lakes drain into the northeast side of Bristol
Bay through the Naknek River (fig. 1). All are
glacial in origin, dating from Wisconsin times
(Midler, 1952; and Karlstrom, 1957). Naknek
Lake comprises three major basins and a shallow
outwash plain. The basins, Iliuk Ann, North
Arm, and South Bay, and the outwash plain, West
End, will be referred to hereafter without refer-
ence to Naknek Lake. The maximum depths are
not known for Murray, Idavain, or Hammersly
Lakes. The other lakes vary between a maximum
depth of 53 m. in Coville Lake and 173 m. in Iliuk
Arm.

The lakes and basins of the Naknek system in-
clude a broad range of environmental types. Most
of them are oligotrophic and usually have ice
cover from December through early May. Iliuk
Ann frequently does not freeze over completely,
probably because of its depth and excessive tur-
bidity, which is due to glacial melt water and
volcanic ash. In Iliuk Arm, Secchi disk visibility
is generally less than 0.5 m., while in the other
basins and lakes it ranges between 3 and 12 m. A
horizontal turbidity gradient occurs in South Bay,
increasing in intensity toward Iliuk Arm. Ther-
mal gradients commonly exist, although classical
thermoclines develop only occasionally and are un-
stable. The waters are slightly alkaline, and oxy-
gen levels remain at or near saturation at all
depths measured throughout the year. The basic

limnology of lakes in the Naknek River system is
described in detail elsewhere.2

MATERIALS AND METHODS

Most pygmy whitefish were collected in the
Naknek system with small otter trawls, tow nets,
beach seines, and small-meshed gill nets. A few
specimens were collected with fyke nets and float-
ing lake traps and by divers using hand nets.
These same methods were used to sample juvenile
sockeye salmon in various stages of their fresh-
water life. Heard (1962) described the small-
meshed gill nets, and the three other principal
types of gear are described below. All mesh sizes
are given in stretch measure.

The otter trawls were Gulf Coast shrimp try-
trawls about 6 m. long, 2.6 m. wide, and 0.6 m.
deep. The cotton webbing varied from 50.8-mm.
mesh in the front section to 25.4-mm. in the cod
section, with a 13-mm. mesh cod liner. The foot-
rope was weighted with a 19-mm. mesh chain, and
the otter doors were 30.5 by 45.7 cm. Except for
use of a tow cable guide ring on the transom, our
use of these trawls behind an outboard skiff was
basically the same as described by Baldwin (1961) .

Trawl drags varied in time, in length of drag,
and in depth. Generally they were between 8 and
15 minutes long and covered from 325 to 1,000 m.
The trawls were fished effectively for pygmy
whitefish to depths of 79 m.

The tow nets were 3.1 m. in diameter and 6.9
m. long, and they were used generally at night in
limnetic (offshore or open water) portions of the
lakes. They were towed behind two outboard
skiffs with the. top of the net at the surface or 3.1
m. deep. A standard tow was 492 m. Mesh sizes
of nylon webbing varied from 38 mm. at the net
opening to 3 mm. in the cod end. Burgner (1960)
describes the construction and general use of this
net. A 1-m. tow net such as that described by .
Johnson (1956) was used to collect one sample of
pygmy whitefish in Brooks Lake.

Three types of beach seines were used. The two
principal types, which were set in a semicircular
pattern from shore with an outboard skiff, were
3.1 m. deep and 32.8 or 42.6 m. long. The 32.8-m.
seine consisted solely of 3 mm. webbing, and the

1 The annual field reports of the research operations at Brooks
Lake (1957-62) are on file at the Bureau of Commercial Fish-
eries Biological Laboratory. Auke Bay, Alaska.

PYGMY WHITEFISH OF SOUTHWEST ALASKA
7195-358 O — 66 3

'Hartman, Wilbur L.. and Robert L. Burgner. The limnology
of sockeye salmon nursery lakes in southwest Alaska. The
manuscript is filed in the U.S. Bureau of Commercial Fisheries
Biological Laboratory, Auke Bay, Alaska.

557

42.6-m. seine consisted of a center section (9.8 m.
long) of 6-mm. webbing and two end sections (16.4
m. long) of 12-mm. webbing. The third type was
1 m. deep with 3-mm. webbing and was either 3.1
or 6.1 long.

Most collections of pygmy whitefish were pre-
served and processed for various biological data;
specimens from the other collections were dis-
carded after the catch was recorded. Fork lengths
were measured in millimeters and weights in
tenths of grams. Most collections were preserved
in 10-percent formalin for at least 48 hours before
processing. The conversion factor of 0.977 to ac-
count for shrinkage was applied to length data on
one group of fresh specimens. All lengths given
are preserved lengths or equivalents. Because
Eschmeyer and Bailey (1955) presented their
pygmy whitefish data in total lengths, we deter-
mined factors for converting fork lengths to total
lengths. Fork length times 1.0777 equals total
length for specimens shorter than 100 mm., and
fork length times 1.0845 equals total length for
specimens longer than 100 mm.

Biological information determined from indi-
vidual specimens included age and growth deter-
minations, stomach content analyses, and repro-
ductive data. Age and growth were analyzed
from scale samples and length frequencies. Stom-
ach content analyses were made either on all of
the specimens or on random samples from different
collections. The occurrence of food items was
determined for individual fish, while volumetric
analyses were made by combining food items from
all fish in a specific collection. Sex ratios and age
and vlength at maturity were determined for ran-
dom samples or for all fish in different collections.
Egg content was determined for 85 females by
total count.

DISTRIBUTION AND ABUNDANCE OF
PYGMY WHITEFISH

Pygmy whitefish have the greatest discontinuous
range of any fresh-water fish in North America ac-
cording to Eschmeyer and Bailey (1955). In ad-
dition to its occurrence in Lake Superior of the.
Atlantic slope, this species has been recorded from
the Columbia River drainage in Washington,
Montana, and British Columbia (Schultz, 1936;
AWisel and Dillon, 1954) and from the Fraser,
Skeena, Yukon, and Mackenzie River systems of

the Pacific and Arctic slopes (Carl, Clemens, and
Lindsey, 1959). It also occurs in both Pacific and
Bering Sea drainages of southwest Alaska, hav-
ing been reported from the Nushagak (Snyder,
1917), Chignik (Kendall, 1917), Naknek (Mer-
rell, 1964), and Kvichak (personal communica-
tion, Ole A. Mathisen and O. E. Kerns) River
systems. Pygmy whitefish probably occur in other
Bristol Bay river systems on the Alaska Penin-
sula, such as the Ugashik and Egegik, where large
lakes appear to provide suitable habitat.

Eschmeyer and Bailey (1955) concluded that
the present disjunct populations of pygmy white-
fish are all referable to the same species and most
likely represent relicts of a continuously distri-
buted species in late Pleistocene that survived in
deep lakes after the retreat of Wisconsin glacia-
tion. McCart (1963) compared meristic and
morphological variation in pygmy whitefish from
British Columbia with those from other areas and
found the species to be highly variable both within
and between populations.

The sizes attained by pygmy whitefish in dif-
ferent geographic areas varied, most likely be-
cause of differences in growth rates related to dif-
ferent environments. The maximum size reported
from Lake Superior was 149 mm. Carl, Clemens,
and Lindsey (1959) reported a population of
"giant" pygmy whitefish in Maclure Lake, British
Columbia. McCart (1963) found pygmy whitefish
in this lake as large as 262 mm. The maximum
sizes in the Naknek system varied considerably
between lakes, ranging from 84 mm. in Brooks
Lake to 163 mm. in South Bay (fig. 2).

NAKNEK SYSTEM

Pygmy whitefish are widely distributed through-
out the Naknek system and were collected in every
major water area in the system except Idavain and
Murray Lakes and West End (table 1). No at-
tempt was made to collect them in Idavain Lake,
and only one small-meshed gill-net set, which was
unproductive, was made in Murray Lake. Pygmy
whitefish may have been collected in 1962 from the
West End in tow nets, but the discarded specimens
were recorded on field data sheets only as "white-
fish." It is likely that they do occur in these three
major areas, however.

The abundance of pygmy whitefish varied
throughout the system. The distribution is best

558

U.S. FISH AND WILDLIFE SERVICE

Figure 2. — Pygmy whitefish from the Naknek system.
From top to bottom : 5-year-old mature female, 163 mm.
long, collected November 9, 1962, in Soutb Bay ; 2-year-

old immature female, 98 mm. long, collected November
9, 1962, in South Bay ; 3-year-old mature female, 76
mm. long, collected November 7, 1962, from Brooks Lake.

known in Brooks Lake where the greatest sam-
pling effort was expended. Pygmy whitefish were
collected in all sections of Brooks Lake, and two
areas of heavy abundance were found at opposite
ends of the lake (areas 1 and 5 (fig. 1)). They
also occurred throughout. South Bay and Iliuk
Ann. A concentration of this fish apparently oc-
curs in the semiprotected bay of South Bay near
the mouth of Brooks River and in the upper end
of Iliuk Arm. The known distribution of pygmy
whitefish in North Arm is spotty, but it is believed
to be widely distributed in this basin. In 1962 and
1963, small whitefish were not specifically identi-
fied on field collection sheets of seine records from
that basin. We suspect that at least some of these
were pygmy whitefish. In Grosvenor Lake, pygmy
whitefish were collected in most areas of the lake;
but, in Coville Lake, they were collected only from
the east end of the lake. The one Hammersly Lake

collection was made near the lake outlet.

The most widely used sampling gear through-
out the system was tow nets, which was used in
open-water limnetic, areas, primarily to sample
juvenile sockeye salmon. Otter trawls, gill nets,
and seines, which were more effective than tow
nets in sampling pygmy whitefish, were used to
different degrees in different areas (table 1) . The
unknown vulnerability of pygmy whitefish to dif-
ferent types of gear and the unequal use of each
type in various lakes and basins should be kept
in mind when considering relative abundance.

On the basis of the number of specimens ob-
tained in other geographic areas by previous col-
lectors, populations of pygmy whitefish may oc-
cupy a more dominant role in the overall fish
population structure in parts of the Naknek sys-
tem than in other areas. In the Lake Superior
study, the greatest single collection of pygmy

PYGMY WHITEFISH OF SOUTHWEST ALASKA

559

Table 1. — Sampling efforts l with otter trawls, low nets, small-meshed gill nets, and beach seines in Naknek system and percent

of samples yielding pygmy whitefish, 1961-68

Otter trawl

Tow net

Gill net *

Seine

Sampling area and year

Sampling
efforts

Samples

with pygmy

whitefish

Sampling
efforts

Samples

with pygmy

whitefish

Sampling
efforts

Samples

with pygmy

whitefish

Sampling
efforts

Samples

with pygmy

whitefish

Brooks Lake:

1961..

Number

Percent

33
43

Number

108
154

60
41

101
53
20

57
61
39

49
72
36

32
94
12

21
52
44

Percent

31
8
8

0
2
2

3
4
5

4
10
3

2
6
6

1
0

30
0

Number

Percent

Number

5
37

Percent

1962..

2
9

100
78

1963..

Coville Lake:

1961

1962..

15
5

0
0

1
3

100
0

324

1963

Grosvenor Lake:

1961

7
26

1962.

21
1

1
8
2

10
100

100
75
100

3 12

1963

Naknek Lake:
South Bay:

1961

47
6

12
2

1962

100
100

100

1963

Iliuk Arm:

1961

1962.

1963

3
3

100
100
100

100

North Ann:

1961

1962

1963..

West End:
1961

1962

1963

Hammersly Lake:

1962

1
1

100
0

Murray Lake:

1962

Brooks River:

1963 _

100

' A sampling effort equals one trawl haul, tow net haul, gill net lift, or individual seine haul.

2 Includes only those gill net sets with mesh sizes 1-inch stretch measure or smaller.

3 Not including sampling efforts containing unidentified small whitefishes which may have included pygmy whitefish.

whitefish was 171 specimens taken in an otter trawl
in Siskiwit Bay (Eschmeyer and Bailey, 1955).
Our largest single collection was 1,701 specimens
taken in a beach seine haul on August 14, 1962,
in Brooks Lake (table 2). The largest Lake
Superior collection had about 80 percent age 0 +
fish, while the largest Brooks Lake collection had
100 percent age 0+ fish. Our second largest col-
lection was made July 10, 1962, by a trawl drag
in Brooks Lake that yielded 1,567 age 1+ and
age 11+ fish. A beach-seine haul in South Bay on
August 4, 1962, yielded 964 specimens (table 2).
Of these, 962 were age 1+ and older. All of the
1961-63 collections of pygmy whitefish from the
Naknek system in which 10 or more specimens
were caught in a sampling effort are listed by
date, area, gear, depth, and number of specimens
in table 2.

ECOLOGICAL AND SEASONAL DISTRIBUTION

Pygmy whitefish occupy a wide variety of eco-
logical habitats in the Naknek system. They were
caught not only in benthic habitats, ranging from

a depth of 168 m. (in Iliuk Arm and North Arm)
to littoral areas less than 1 m. deep, but also in
limnetic areas at or near the surface over deep
water and in several streams.

The capture of pygmy whitefish in littoral areas
with seines and trawls and in limnetic areas with
tow nets was somewhat unexpected. In Lake
Superior, Eschmeyer and Bailey (1955) caught
pygmy whitefish only in benthic areas below 10
fathoms. Except for six specimens caught in gill
nets, all Lake Superior pygmy whitefish were
caught in otter trawls.

Most littoral catches of pygmy whitefish in the
Naknek system were made at the northeast end of
Brooks Lake and in a semiprotected bay in South
Bay (areas 1 and 8, fig. 1). Part of this littoral
area in Brooks Lake consisted of a shallow sandy
shelf 1 to 2 m. deep that extended 300 to 500 m.
into the lake. This shelf is subject to heavy wave
action and is barren of vegetation except for small
patches of Ranunculus sp. Large schools of age
0+ pygmy whitefish were observed by biologists

560

U.S. FISH AND WILDLIFE SERVICE

Table 2. — Collections of pygmy whitefish from the Naknek system in which 10 or more specimens were caught per sampling

effort ' by area, gear, depth, and number of specimens, 1961-63

Sampling area and
date

Brooks Lake:

July 17, 1961.

July 18, 1961.

July 20, 1961.

July 21, 1961.

Aug. 7, 1961..

Aug. 8, 1961..

Aug. 10, 1961.

Aug. 11, 1961.

Sept. 1, 1961..

Sept. 14. 1961

Sept. 26, 1961.

June 29, 1962.

July 10, 1962.

July 11, 1962.

July 22, 1962.

July 23, 1962.

July 26, 1962.

July 27, 1962.

Aug. 10, 1962.

Aug. 14, 1962.

Sept. 14, 1962

Nov. 7, 1962..

Nov. 8, 1962..

July 2, 1963..

July 8, 1963..

July 16, 1963.

July 22, 1963.

July 26, 1963.

Aug. 7, 1963.

Aug. 9, 1963.

Aug. 20, 1963

Dec. 16, 1963.
South Bay:

July 15, 1962.

July 22, 1962.

Num-
bered
area2

Type of gear

Otter trawl

....do

....do..

....do

Tow net (3.1 m.).

....do

Otter trawl

Tow net (3.1 m.).
Otter trawl

— .do..

....do...

....do....

....do—.

....do

Tow net (1-m.) —
Otter trawl

— .do.

Seine

....do

—do

— .do..

—do—

Otter trawl

—do —

Gill net

— .do—

Hand net

Seine

do.

Gill net

Otter trawl

Gill net.

Seine -.

Gill net

do.

Seine.. .
do..

Total

Depth

specimens

caught

Meters

Number

290

150

308

344

0-3.1

321

0-3.1

3. 1-6. 1

425

1,567

0-1

168

1,701

306

3 75

Sampling area and
date

South Bay— Con.

July 23, 1962, . ,

July 23, 1962—

July 23, 1962...

Aug. 4, 1962...

Aug. 4, 1962.-.

Aug. 4, 1962—

Aug. 24, 1962- .

Sept. 26, 1962..

Nov. 9, 1962—

Nov. 10, 1962-

Apr. 16, 1963..

May30, 1963...

June 14, 1963..

July 11, 1963—

Oct. 29. 1963...

Nov. 5, 1963- -

Dec. 12, 1963..
Brooks River:

July 27, 1963—

Aug. 24, 1963..

Aug. 24, 1963. .

Aug. 25, 1963. .

Aug. 25, 1963..
Iliuk Arm:

July 9, 1963....

July 27, 1963...
North Arm:

July 22, 1962—

Aug. 9, 1962.-
Coville Lake:

June 7, 1962. ..

June 7, 1962 . . .

June 9, 1962 —

July.12, 1962. -
Grosvenor Lake:

June 30, 1962..

Aug. 5, 1962—

Aug. 19, 1963..
Hammersly Lake:

Aug. 20, 1962. ,

Num-
bered

Type of gear

Seine

.—do....

do....

do...

do....

do...

.do..

Gill net.

do...

do-
Seine

.do..

Gill net.
....do...
do-

Seine

Otter trawl.

do„

Seine. ..
do..

Gill net.
do-

Seine...

do.

Otter trawl.
do

Gill net.

Depth

Meters

3
3
3
3
3
2
2
2
2
2
2
2
2
2

3
3

169
169

2
2
2
2

Total
specimens
caught

Number

16
25
16
63
10

542
16
22

345
11

964
96

148

124

116
20
12
12

144
33
66
81

468
178
18
200
150

10
21

12
10
10

48
64
96

1 A sampling effort is an individual trawl haul, tow net haul, beach seine haul, or gill net lift.

- See figure 1.

3 Gill net was buoyed so that it was fishing horizontally 3 m. off the bottom in water 78 m. deep.

skin diving along this shelf during June, July, and
August, 1962 and 1963. These fish were routinely
caught with seines or hand nets. On July 23, 1962,
168 age 0+ pygmy whitefish were caught on the
edge of this shelf in a 1-m. tow net (table 2) . This
particular catch was made in an area where Arctic
Terns (Sterna paradisaea) were feeding on small
fishes near the surface, presumably pygmy white-
fish. Littoral collections in South Bay were made
during April, May, June, July, August, Sep-
tember, October, November, and December in
either 1962 or 1963 (table 2). Pygmy whitefish
apparently remain in the littoral area of this bay
throughout most of the year. No sampling was
attempted during late winter or early spring.

In addition to the above areas, substantial num-
bers of pygmy whitefish were also caught in lit-
toral areas in the narrows between South Bay and
Iliuk Ann, at the upper end of Uiuk Arm, and

near the outlets of Grosvenor and Coville Lakes
(areas 9, 11, 12, and 14, fig. 1) .

Pygmy whitefish in the Naknek system appar-
ently are associated with the benthic zone at all
lake depths. Benthic collections have been made
from all depths in Brooks Lake with seines, trawls,
or gill nets and from shallow shoreline and the
deepest areas of North Arm and Iliuk Arm with
seines and gill nets. This distribution differs from
the bathybenthic distribution found in Lake Supe-
rior (Eschmeyer and Bailey, 1955) and the inter-
mediate benthic distribution found in four British
Columbia lakes (McCart, 1963). In each of these
studies, pygmy whitefish were sampled primarily
with one collecting gear — trawls in Lake Superior
and gill nets in British Columbia.

Although pygmy whitefish are generally asso-
ciated with the benthic zone, concentrations of
them were typically spotty. A series of 11 conse-

PYGMY WHITEFISH OF SOUTHWEST ALASKA

561

cutive seine hauls made along a 600-m. stretch of
beach in South Bay on August 4, 1962 (table 3),
shows that catches are variable and suggests that
pygmy whitefish are frequently grouped in large
schools. Approximately 80 percent of the pygmy
whitefish collected throughout the Naknek system
came from specific sampling efforts that yielded
100 or more specimens.

Table 3. — Age 0+ and older pygmy whitefish caught in 11
consecutive seine hauls in South Bay, August 4, 1962

Seine haul number

Fish per haul

Age0+

AReI+
and older

Number
0
1
1
2
12
20
0
0
4
7
2

Number
642

5. -.-

6. .

341

10 . . _ - -

11 .

962

Underwater observations on the schooling and
feeding behavior in lower Brooks River indicated
that pygmy whitefish are frequently grouped in
schools of several thousand fish. Fishes in these
schools were evenly spread out over several meters
of stream bottom. Individuals fed independently
of other fish, and the undisturbed school of fish
would slowly move from one area to another.
When disturbed by an observer or predator, schools
of pygmy whitefish in Brooks River became tightly
grouped.

The distribution of age 0+ pygmy whitefish,
particularly in Brooks Lake, changes in late sum-
mer. > Many of these young whitefish remain in
littoral areas on the sandy shelf along the north-
east shoreline of Brooks Lake throughout much
of the summer, but by mid-August they begin dis-
appearing. They are scarce in this area in Sep-
tember. During the same period, limnetic catches
of pygmy whitefish in tow nets increase. Age 0 +
sockeye salmon in Wood River Lakes behave simi-
larly (Burgner, 1960). Naknek system age 0 +
sockeye salmon also show this behavior, although
it is not as pronounced. The reasons for this fall
change in distribution of young pygmy whitefish
are not known. The autumn lake turnover,
changes in diet attendant with shifts in food sup-
plies, or other limnological changes may be in-

volved. During the fall, weather on the Alaska
Peninsula is characterized by severe storms with
gale winds. The resultant heavy wave action may
tend to disperse young pygmy whitefish from
littoral areas.

About 95 percent of the pygmy whitefish caught
with tow nets in all lakes and basins were age 0 +
fish. In 1961 tow nets were used in Brooks Lake
from mid-August throughout September, while
otter trawls were used primarily from mid-July
to mid- August. A comparison of length frequen-
cies of pygmy whitefish caught in limnetic areas
with tow nets with those caught in benthic areas
with trawls during these periods indicates (fig. 3)

t 70

I AGE 1+
AGE0+ I AND OLDER

3 0 40l 50 60

FORK LENGTH (MM.)

Figure 3. — Comparison of length frequencies of pygmy
whitefish caught from mid-July to mid-August in
benthic areas with otter trawls with those caught from
mid-August through September in limnetic areas with
3.1-m. -diameter tow nets, Brooks Lake, 1961.

that while both age 0+ and older fish were caught
in the benthic zone, most of those caught in the
limnetic zone were age 0 + . Differences in the
selectivity of the two gears could have affected
these catches; however, we do not feel trawls were
selectively collecting older, larger pygmy white-
fish since comparative catches of other fishes sug-
gest that larger specimens are usually caught in
tow nets. Our interpretation of these data is that
fewer age 1+ and older pygmy whitefish were
present in limnetic areas than in benthic areas.
Differences in length frequencies of age 0+ fish
shown in figure 3 are due to sampling periods and
not to differences in size of fish caught in separate
ecological areas or with different sampling gear.
In 1962 and 1963 when tow nets were used in
Brooks Lake throughout July and August, no
pygmy whitefish were caught in limnetic areas

562

U.S. FISH AND WILDLIFE SERVICE

until late August. Some age 0+ fish may have
been present in limnetic areas before this time,
although they probably would have been too small
to capture in the available gear. Few tow net
hauls were made in September, except in Brooks
Lake in 1961.

Although no permanent stream populations of
pygmy whitefish are known to exist in the Naknek
system, large numbers seasonally occupy the lower
100 to 400 m. of Brooks River. These fish are part
of the South Bay population (area 8, fig. 1) and
do not go above a rapids area below Brooks River
falls. They occupy lower Brooks River from late
June to early September for feeding and from
mid-November to mid-December for spawning.
Feeding pygmy whitefish in Brooks River char-
acteristically occupy neither the fastest moving
nor the slowest moving water, but seem to prefer
a moderate current adjacent to a faster one.

A few pygmy whitefish have been collected or
observed in other streams in the system. With the
possible exception of an annual downstream drift
of spent fish in midwinter, these collections ap-
parently represent only sporadic downstream
movements of fish from Brooks, Coville, and
Grosvenor Lakes. LJnderwater surveys of upper
Brooks River from May through November and
of Coville River from May through August re-
vealed that pygmy whitefish did not occupy these
streams during this period.

ASSOCIATED FISHES

Nineteen species of fishes were collected with
pygmy whitefish in various parts of the system.

The percent frequency occurrence of these species
(table 4) provides a basis for discussing associated
species. Throughout the system the cottids Coitus
aleuticus Gilbert and C. cognatus Richardson
were the most frequent associates, occurring in 55
percent of all sampling efforts that yielded pygmy
whitefish (table 4) . Juvenile sockeye salmon were
the second most frequent associates, occuring in 42
percent of the samples. Next in frequency of
association with pygmy whitefish were ninespine
sticklebacks, threespine sticklebacks, round white-
fish, and least cisco (table 4). The greatest num-
ber of sympatric associates in a specific area was
17 species in South Bay.

Certain fishes in the Naknek system were not
caught with pygmy whitefish in all lake areas.
Least cisco, humpback whitefish, pond smelt, and
longnose sucker, were collected widely in other
parts of the system but not in Brooks Lake.
Alaska blackfish, abundant in Brooks Lake, were
not collected in South Bay or Iliuk Arm. Dif-
ferences in sampling gear and effort may account
for species not being caught in certain areas.

The two most common associates of pygmy
whitefish in Lake Superior were cottids and nine-
spine sticklebacks (Eschmeyer and Bailey, 1955).
Round whitefish, which were never collected in
association with pygmy whitefish in Lake Su-
perior, occurred in 17 percent of the Naknek sys-
tem samples yielding pygmy whitefish. These
whitefishes were collected together in six of eight
major lakes, basins, or streams (table 4). This
apparent difference in association between pygmy
whitefish and its closest relative in Lake Superior

Table 4. — Percent frequency occurrence of associated fishes in sampling efforts ' that yielded pygmy whitefish

Species

Brooks
Lake

South
Bay

Iliuk
Ann

North
Arm

Coville
Lake

Grosvenor
Lake

Hammersly
Lake

Brooks
River

All areas
combined

Percent
60
35
39

Percent
53
41
36
24
29
20

Percent
38
71
10
38
29
52

Percent
63
25
62
38
50
38

Percent
67
67
25
92

Percent
42
58

Percent
100

Percent
17
33

Percent

67
33

15
2
3

11
3
3
5
3
9
3

1
2

100

50
13

100

1 Sampling efforts of all gears were combined (or each area, then for all areas; see table 1 for total sampling effort by gear and area.

2 Juveniles only.

PYGMY WHITEFISH OF SOUTHWEST ALASKA

563

and the Naknek system may be related to the use
of only trawls in Lake kSuperior and several gears
in the Naknek system. In the present study few
round whitefish were captured in trawls. McCart
(1963), using gill nets, found little or no associ-
ation between pygmy whitefish and mountain
whitefish Prosopium williamsoni (Girard) or lake
whitefish Coregonus clupeaformis (Mitchill) in
Cluculz and Tacheeda lakes, British Columbia.

AGE AND GROWTH
BODY-SCALE RELATION

The relation between body length and the an-
terior scale radius (mm. multiplied by 80) was de-
termined for 456 pygmy whitefish from Brooks
Lake and 500 from South Bay. Data from both
lakes indicate this relation is highly sigmoid.
Rounsefell and Everhart (1953, p. 324) suggest
that problems of curvilinearity can be solved by
omitting the earliest years and back calculating
only those ages that do not deviate appreciably
from linearity. The persistence of a curvilinear
body-scale relation in the older age groups of
Naknek system pygmy whitefish prevented any
linear treatment of older fish. Also, these fish are
relatively short lived, reaching a maximum age of
3 years in Brooks Lake and 5 years in South Bay.
Age was determined from scale annuli, which, ex-
cluding scales from a few older fish, were not
difficult to locate.

Fourth degree polynomial equations were found,
excluding highly spurious intercepts, to fit fairly
closely the empirical data for the body-scale re-
lations of Brooks Lake and South Bay pygmy
whitefish. These equations were calculated from
individual pairs of body-scale observations. Mean
body lengths for each scale radius are plotted
against the calculated relations for both areas
(figs. 4 and 5). Body length at scale formation
is apparently between 22 and 27 mm. as determined
by: (1) staining small fish for the first evidence
of scale development and (2) calculating the inter-
cept for collections of age 0+ fish after scale de-
velopment. Separate equations were necessary for
the Brooks Lake and South Bay collections be-
cause of strikingly different growth rates in the

20 40 60

ANTERIOR SCALE RADIUS (MM.X80)

Figure 4. — Body length-scale radius relation of pygmy
whitefish in Brooks Lake. Solid line is calculated equa-
tion ; points represent mean body lengths for given scale
radii ; dashed line connects estimated intercept of 25
mm. with the logical portion of calculated curve.

160

140

120

100

20 -

/ 't.= 442.62-25.l7622S+0.596IIS2-0.00574S3-+0.00002S4

20 40 60 80 100

ANTERIOR SCALE RADIUS (MM.X80)

120

Figure 5. — Body length-scale radius relation of pygmy
whitefish in South Bay. Solid line is calculated equa-
tion ; points represent mean body lengths for given scale
radii ; dashed line connects estimated intercept of 25
mm. with the logical portion of calculated curve.

564

U.S. FISH AND WILDLIFE SERVICE

two populations.3 Growth rates were back calcu-
lated from these quartic equations.

CALCULATED GROWTH

Fork lengths attained at each year of life and
the annual increments were calculated by sex for
330 pygmy whitefish from Brooks Lake (table 5)
and 779 from South Bay (table 6). A comparison
of these growth rates reveals that pygmy whitefish
grew considerably faster in South Bay than in
Brooks Lake. The largest pygmy whitefish col-
lected from Brooks Lake was an 84-mm. mature
female that had just completed its third growing
season. Two slightly older (III+) but smaller,
slower growing females were collected from
Brooks Lake, In South Bay the largest and oldest
pygmy whitefish was a 163-mm. age V mature
female.

During their first year of life, males in Brooks
Lake grew slightly faster than females. In sub-
sequent years in Brooks Lake and in all years in
Naknek Lake, females consistently grewT at a faster
rate than males (tables 5 and 6). Males in Lake
Superior grew slightly faster than females dur-
ing the first year, grew at about the same rate as
females during the second year, and grew slower
than females during later years. Male pygmy
whitefish in Lake McDonald, Mont., grew faster
in their first year but slower than females in sub-
sequent years, while females in Bull Lake, Mont.,
grew faster in all years (Eschmeyer and Bailey,
1955). With minor variations, these growth pat-
terns are similar to those reported by McCart
(1963) for pygmy whitefish in MacLure, McLeese,
Cluculz, and Tacheeda Lakes, British Columbia.
Males grew at about the same rate as females for
the first 2 years, after which females consistently
grew faster than males.

Table 5. — Average fork length at time of capture and
calculated length at end of each year of life for pygmy
whitefish collected in Brooks Lake during summer and fall
1962

3 Additional study is needed to understand fully the curvi-
linear body-scale relation of these whitefish. Few specimens
have been collected from South Bay as small as the age I and II
fish from Brooks Lake with usable scales. Obviously the cal-
culated curve for South Bay fish below 75 mm. is not biologically
valid. With adequate data the lower portion of the South Bay
curve could approach the Brooks Lake curve for the same size
fish, in which ease a single equation might express the body-
scale relation for both populations. The problem is aggravated
by the ease with which small pygmy whitefish lose their rela-
tively large scales. Also, South Bay fish grow as large in 1 year
as Brooks Lake fish do in 2 years, and it is not known what ef-
fect different growth rates between populations or between year
classes within the same population have on body-scale relation
curvilinearity.

Age group

Sex

Fish

sample

Fork
length

at
capture

Calculated fork length
at end of year of life

/Male

1 Female

/Male

IFemale

/Male

IFemale

/Male

Num-
ber
80
70
32
134
2
12

Mvi.
57.2
57.2
63.9
69.6
70.5
74.5

Mm.
42.4
42.4
41.0
41.7
41.9
35.6
42.0
41.6
42.0
41.6
114
216

Mm.

61.3
65.2
66.1
64.2
61.6
65.1
19.6
23.5
34
146

III

68.9

Grand average

71.3

68.9

71.3

Average increment..

/Male.

7.3

6.2

Number of fish

/Male

IFemale

114
216

2
12

Table 6. — Average fork length at time of capture and cal-
culated length at end of each year of life for pygmy
whitefish collected in South Bay during summer and
fall 1962

Age group

Sex

Fish
in

sam-
ple

Fork
length
at
cap-
ture

Calculated fork length at end of
year of life

/Male

IFemale

/Male

IFemale

/Male

IFemale

/Male

IFemale

/Male

IFemale

/Male

No.

161

175

214

181

Mm.
77.0
76.2
108.6
112.4
117.6
127.1
132.5
138.2

Mm.
61.5
60.6
62.8
64.7
65.0
64.1
64.0
64.2

Mm.

100.7
103.3
98.9
99.6
103.3
103.8

II ...

114.1
116.2
116.6
118.0

119.9
129.1

155.0

59.0
62.4
62.8
62.4
62.8
393
386

82.4
100.6
102.8
38.2
40.0
232
211

117.5
114.6
117.0
14.0
14.2
18
30

125.7

119.9

128.6

6.3

11.6

135.8

/Male

7.2

Number of
fish.

/Male
IFemale

393
386

The annual growth of female pygmy whitefish
from Lake Superior (Keweenaw and Siskiwit
Bays) , Mich., and Bull Lake and Lake McDonald,
Mont., when compared with growth of females
from Brooks Lake and South Bay (fig. 6),
revealed that the slow growth in Brooks Lake was
similar to that in Lake Superior, while growth
in South Bay was intermediate between growth
in Bull Lake and Lake McDonald. Comparisons
of annual growth rates of female pygmy whitefish
from the Naknek system with those from Mac-
Lure, McLeese, Cluculz, and Tacheeda Lakes (Mc-
Cart, 1963) indicate (fig. 6) that growth in South
Bay was intermediate between growth in Mc-
Leese and Cluculz Lakes, while growth in Brooks
Lake was slower than in any of the British Colum-
bia lakes. The length attained by pygmy white-

PYGMY WHITEFISH OF SOUTHWEST ALASKA

565

SOUTH BAY. NAKNEK LAKE

KEWEENAW BAY.
LAKE SUPERIOR

SISKIWIT BAY.
LAKE SUPERIOR

BROOKS LAKE

260

240

220

200

180

160

140

120

100

MocLURE LAKE — i ,-""''

McLEESE LAKE -
SOUTH BAY,

\ZC

pCLUCULZ LAKE

- NAKNEK LAKE -i /"/ ^^-"O-" ...-
j/ /^^ . —

-1

LTACHEEDA LAKE

1— BROOKS LAKE

-r

r i i

1 1

1 1 I

1 2

3 4

5 6 7

YEAR OF LIFE

Figure 6. — Calculated growth of female pygmy whitefish
from Brooks Lake and South Bay. Naknek River sys-
tem, compared with data from Lake Superior, Mich.,
and Lake McDonald and Bull Lake, Mont., ( Eschmeyer
and Bailey, 1955) and MacLure, McLeese, Cluculz, and
Tacheeda Lakes, British Columbia (McCart, 1963).
Data from Eschmeyer and Bailey were converted from
total to fork length.

fish in MacLure Lake is by far the greatest, known
for this species.

EMPIRICAL GROWTH

Although the average annual growth was not
calculated for all lakes in the Naknek system,
length frequency distributions of collections from
six areas (table 7) provide a basis for growth com-
parison. The broad range of length frequencies
suggests differences in growth rates that reflect
the ecological differences in various lakes and
basins in the system. The oldest pygmy whitefish
collected from Grosvenor Lake, Hammersly Lake,
and North Arm were age III+ females 95, 96,
and 100 mm.4 long, suggesting growth rates inter-
mediate between those from Brooks Lake and

South Bay. In Iliuk Arm the length of the larg-
est pygmy whitefish, a 132-mm. age IV+ female,
is comparable with the average calculated length
of the same age fish in South Bay.

The striking difference in growth of pygmy
whitefish in Brooks Lake and South Bay is ap-
parent during the first summer. The earliest col-
lections of age 0+ pygmy whitefish were made
there in late June and early July. In early July,
age 0+ pygmy whitefish were about equal in
length in the two areas, averaging between 20 and
23 mm. long. By late August, however, age 0 +
pygmy whitefish from South Bay were almost 10
mm. longer than fish from Brooks Lake (fig. 7).
Based on the average calculated growth rates,
South Bay pygmy whitefish are about 20 mm.
longer than Brooks Lake fish at the end of the first
growing season ( fig. 6 ) . There was little difference
in the lengths of age 0+ fish taken in mid- July
from Brooks River, North Arm, South Bay, and
Brooks Lake. A sample of age 0+ pygmy white-
fish from Grosvenor Lake in mid- August indicated
an average length similar to that in Brooks Lake in
mid-August.

An interesting comparison of the first year
growth of pygmy whitefish with that of its close
relative, round whitefish (fig. 8), indicates that
age 0+ samples of both species collected in the
same seine haul from Brooks Lake on August 10,
1962, had no overlap in lengths and round white-
fish were considerably larger.

FOOD HABITS

Stomach contents were examined from 62 age
0+ and 396 age 1+ and older pygmy whitefish.
The age 0+ fish were from South Bay and Brooks
and Grosvenor Lakes, while the older fish were
from Brooks, Grosvenor, and Hammersly Lakes,
South Bay, North Arm, Iliuk Arm, and Brooks
River. These fish were collected with seines, otter
trawls, and gill nets.

DIET OF AGE 1+ AND OLDER FISH

Insects and zooplankton were the two principal
groups of food in the diet, of age 1+ and older
pygmy whitefish in the Naknek system (table 8).
The relative importance of these two foods varied
greatly between lakes. I )ipteran insects dominated

'Two larger females, 102 and 115 mm. long were collected In
North Arm with (rill nets on Aug. 9. 11HVJ. Both specimens were
mutilated, however, and no scales were available for aging.

566

U.S. FISH AND WILDLIFE SERVICE

the South Bay and Iliuk Arm samples, while,
crustacean zooplankton dominated samples from
Brooks Lake. Stomach samples from Brooks
River fish contained predominantly insects, while
samples from North Arm and Hammersly and
Grosvenor Lakes fish contained about equal
amounts of insects and zooplankton.

Larvae, pupae, and adult dipteran and plecop-
teran nymphs were the main insects eaten by Nak-
nek system pygmy whitefish. Dipteran larvae and
pupae (chiefly Chironomidae) accounted for 68,
50, 33, and 88 percent of the food volume from the
four South Bay collections (table 8) . Forty-seven
percent of the volume of stomachs examined from
Iliuk Arm consisted of dipteran adults. In all
other samples, adult insects accounted for 5 percent
or less of the volume. Plecopteran nymphs were
the second most important insects eaten, account-
ing for 32 percent of the volume from a South Bay

sample and 40 percent from a Brooks River sam-
ple. Five additional orders of insects were occa-
sionally eaten by pygmy whitefish, but these never
accounted for more than 5 percent of the volume
of any sample.

The principal crustacean foods eaten were the
cladocerans Daphnia, Bosmina, and Holopedium
and the copepods Cyclops and Diaptomus (table
8). The crustacean percentage of total volume
varied from a trace (South Bay, August 24, 1962)
to 100 percent (Brooks Lake, November 7, 1962).
Ostracods and amphipods, which were the prin-
cipal foods eaten by pygmy whitefish in Lake
Superior (Eschmeyer and Bailey, 1955), were
minor items in the diet of Naknek system fish,
occurring in only 8 of 13 samples and never ac-
counting for more than 6 percent of the sample
volume.

Table 7. — Length frequencies of -pygmy whitefish age 1+ and older collected from various areas in the Naknek system, 1961-63

[M represents males; F, females; C, sexes combined)

Brooks Lake

Grosvenor Lake

Hammersly Lake

Fork length in mm.

Aug. 7, 1961

Sept. 14, 1961

June 29, 1962

July 10,
1962

Total

Aug. 5, 1962

Aug. 19,
1963

Total

Aug. 20, 1963

Total

26-28

29-31

32-34 .

35-37

38-10

254

361

276

111

114

102

116

406

495

323

123

152

146

116

108

41-43

44-46 ..

9
28
68
44

5
14
14

2
3

1
1

1
2
4

10
5
3
2
3
3
2

2
7
14
13

47-49 .

4
9
22

15
8
1
1

1
9
14
14
9
7
5
3
3
1

6
3
3
1

2
2
4
6
5
4
3
2

50-52

1
1

7
12
10

6
10
9
4
3
3
2
2
1

53-55

56-58

59-61 .

62-64

1
2

2
2

65-67

68-70

71-73

74-76 .

77-79

80-82

1
1

83-85 _.

86-88 .

89-91

92-94

95-97 _._

98-100

101-103

104-106

107-109

110-112

113-115

116-118. .

119-121 .

122-124

125-127

128-130...

131-133

134-136

137-139_ .'..

140-142

143-145

146-148

149-151

152-154

PYGMY WHITEFISH OF SOUTHWEST ALASKA

567

Table 7.

-Length frequencies of -pygmy whitefish age /+ and older collected from various areas in the Naknek system,

1961-63— Continued

North Arm

Illuk Arm

South Bay

Fork Length
in mm.

July 21-Aug. 9, 1962

Total

Aug. 2, 1962

July 9,
1963

July 27,
1963

Total

July 22, 1962

Aug. 4, 1962

Total

26-28

29-31

32-34

35-37

38-40

41-43

44-46

47-19

50-52 -

53-55 .

1
1
4

5
4

2
1
4

5
5
5
3
3
2
2

56-58 -

59-€l

1
1
4

14
12

8
6

62-64 .

2
12
23
95
174
193
124
52
10
2

107

244

229

145

65-67

6
13
11
14

68-70

3
1

2
2

71-73 -

229

74-76 .

441

77-79

444

80-82

277

83-85 -

3
4

7
5
6
3
1

4
7
5
6
3
1

86-88

89-91

92-94

95-97

1
1
2

98-100

1
1

101-103

5
4

14
8
7
6
1

104-106

107-109

5
5
6
3
5
2
1
1
3
1
1
1

110-112 .

113-115 ..

116-118

119-121

1
1

122-124

125-127 -.

128-130 ..

1
1

2
2

131-133 ..

134-136

137-139 .

140-142

143-145

146-148

149-151 ..

152-154

Other invertebrates found in the diet were pele-
cypods, nematodes, and arachnids (table 8).
Only pelecypods, which accounted for from 5 to
13 percent in samples from North Arm and
Brooks and Grosvenor Lakes, were of more than
minor importance.

Peri phy ton (diatoms and other algae), which
were present in one Brooks Lake sample and two
Brooks River samples, never accounted for more
than 4 percent by volume of any sample (table 8).

Fish eggs occurred in both of the Brooks River
samples and in the November South Bay samples,
amounting to 3, 14, and 38 percent of the volume of
food (table 8). Although the eggs were partially
digested in some stomachs and could not be iden-
tified, they all appeared to be salmon eggs. Large
numbers of adult sockeye salmon spawn in Brooks
River during the summer and early fall. Even
after spawning is completed in the fall there is
a frequent drift of dislodged eggs out of Brooks

River into South Bay. Kendall (1921) found
salmonid eggs in stomachs of pygmy whitefish
collected from Lake Aleknagik in August, and
Eschmeyer and Bailey (1955) found whitefish
eggs in stomachs of pygmy whitefish collected
from Lake Superior in January. Eschmeyer and
Bailey speculate that fish eggs, when available,
may be an important item in the diet of the pygmy
whitefish.

Sand grains accounted for 29 percent of the
volume in the Grosvenor Lake sample and repre-
sented from 6 to 10 percent of the volume in four
additional samples (table 8). Only two samples,
both from Brooks Lake and containing principally
zooplankton, were entirely devoid of sand grains.
Occasionally fish were found with more than 100
sand grains in their stomachs. Eschmeyer and
Bailey (1955) found sand grains in 9 percent of
t lie Lake Superior fish examined.

568

U.S. FISH AND WILDLIFE SERVICE

I-
o

or
o

Li_

a
m
■
□

BROOKS LAKE
SOUTH BAY
BROOKS RIVER
NORTH ARM
GROSVENOR LAKE

OH"

-L

30
JUNE

ii CD

2 T7

-L

10 20
JULY

10 20
AUGUST

10 20 30
SEPTEMBER

Figure 7. — Length frequencies of age 0+ pygmy whitefish collected in 1962 and 1963. Vertical bar represents length
range ; horizontal line represents mean length of each collection. Asterisk indicates collection was made in 1963.

N=65 1 |

PYGMY WHITEFISH

N=fiq 1 | 1
-A 1 1 1 1

20 30 40

FORK LENGTH (MM.)

Figure 8. — Range and mean length of age 0+ round white-
fish and pygmy whitefish caught in the same seine haul
in Brooks Lake, August 10, 1962. Horizontal bar shows
range ; vertical bar indicates mean length of samples.

Plant debris such as small twigs, bits of wood,
grass, seeds, and spruce needles occurred in nine
samples and accounted for 14 percent of the vol-
ume in both samples from Brooks River (table 8).
The relatively high occurrence of these items in
Brooks River probably represents drift items.

The significance of fish scales in six samples
(table 8) is not understood. All undigested scales
that could be identified were from pygmy white-
fish. No fish remains other than scales were found
in any stomachs. Our observations suggest that
pygmy whitefish might readily ingest any small
bright object either in the current or from the
stream or lake bottom.

PYGMY WHITEFISH OF SOUTHWEST ALASKA

Underwater observations of pygmy whitefish
feeding in lower Brooks River showed that they
frequently picked up mouthfuls of material off
the bottom and passed fine silt, sand grains, and
bits of debris posteriorly through their gill open-
ings. They did not feed along the bottom in a
suckerlike manner, but made short distinct jabs or
darts, apparently at specific food items, such as
insect larvae, when picking up mouthfuls of bot-
tom material. Sand grains and other bits of de-
bris are undoubtedly passed into the alimentary
tract during such feeding behavior. Not all
pygmy whitefish feeding activity in Brooks River
was associated with the bottom. Frequently in-
dividual fish would rise off the bottom, as much as
35 to 50 cm. in water 1 m. deep and would pick
specific items out of the passing current. With the
diet of pygmy whitefish being primarily zooplank-
ton and insects in various parts of the Naknek
system and macrobenthic crustaceans in Lake Su-
perior (Eschmeyer and Bailey, 1955), it is obvious
that the species has a flexible diet and feeding
behavior.

569

Table 8. — Percentage of total volume ' of different food items in stomachs and (in parentheses) percent frequency occurrence 2
for 13 samples of age I + and older pygmy whilefish taken with seines, gill nets, and otter trawls from various parts of the
Naknek system

[T represents Trace]

South Bay

Brooks River

Iliuk
Arm

North
Arm

Gros-
venor
Lake

Ham-
mersly
Lake

Brooks Lake

Food item

Aug. 4,
1962,
Seine

Aug. 24,
1962,
Seine

Nov. 9
1962,
Seine

Apr. 16,

1963,
Gill net

July 28,
1963,
Seine

Aug.

24-25,

1963,

Trawl

July 9,
1963,
Seine

July 22-
Aug. 9,

1962,
Gill net

Aug. 19,
1963,
Trawl

Aug.

17-20,

1962,

Gill net

July 10,
1962,
Trawl

Nov. 7,
1962,
Trawl

July
22-26,

1962,
Trawl

Insects:

Dipteran:

Larvae __

Percent

49
(67)

19
(43)

(6)

9
(13)

(11)

(2)

(15)

(7)
T
(2)

Percent

9
(70)
41
(97)

Percent

33
(50)

Percent

(100)

(5)

Percent

9
(83)

9
(70)

1
(3)

40
(73)

Percent

14
(95)

(80)

(40)

8
(43)

(10)

(13)

(40)

(43)

Percent

7
(59)

16
(70)

47
(85)

(44)

Percent

34
(78)

Percent

(90)

(30)

Percent

28
(75)

34
(88)

Percent

(25)

(18)

Percent

Pupae .

(57)
T

Adults

(5)
4

Plecopteran:

Nymphs,.

32
(73)

(24)

Tricopteran:

Larvae _ ._

(5)

Other insects 3 _

5
(30)

(81)

(30)

Crustaceans:

T
(10)
T
(3)

8
(40)

4
(10)

(21)
2

(21)
6

(26)

(37)

(23)

16
(67)

(89)

(17)

20
(85)

14
(65)

(5)

9
(38)
27
(62)
1
(38)

69
(100)
29
(95)
1
(34)

(100)

(94)

(76)
44

Ostracods _

(100)
T

Amphipods. . . _ .

(4)

(5)

Other invertebrates:

Pelecypods8

(28)

(39)

(10)

1
(10)

1
(17)

(11)

(10)

(32)

(3)

(35)
14
(22)
6
(82)
14
(70)
1
(27)

(4)

(25)

(5)
1

Arachnids...

(2)

(38)

Miscellaneous:

Periphyton 7_ .

(10)
3

(13)
6

(87)
14

(60)
1

(30)

Fish eggs _ _.

(30)
9

(80)
8

(30)
T

(10)

10
(67)

2
(17)

3
(22)

(27)
1
(20)
15
(40)

(26)
1

(21)

(11)
T

(18)
T

(22)

1
(17)
T
(6)

29
(90)

(25)

Plant debris'

(10)
T

Fish scales ___

(5)

Number of stomachs examined..
Percent empty stomachs

68-130

0.11

72-113

0.23

100-134

0.13

80-111

0.09

97-136

0.27

81-144

0.46

27
0

56-130

0.39

10
76-100

0.10

5
52-97

0.18

11
68-80

0.12

0
53-80

0.18

0
55-77

0.17

0
55-77

Mean volume of contents 2 (in

0 06

1 Based on aggregate contents of all stomachs in each sample.
1 Based only on stomachs containing food.

3 Tricopteran adults, coleopteran adults and larvae, hemipteran
nopteran, and collembolan adults.

4 Daphnia lonqiremis, D. rosea, Bosmina coregoni, Holopedium gibberum

s Cyclops strenuus and Diaptomus gracilis.
fl Pisidium.
hyme- 7 Diatoms and filamentous algae.

8 Small sticks, bits of wood, seeds, and leaves.

DIET OF AGE 0+ FISH

Crustacean zooplankton was the major food in
two samples of age 0+ fish — one from South Bay,
July 11, 1963, and one from Brooks Lake, August
14, 1962. Insects and zooplankton were about
equal in volume in the September 26, 1962, South
Bay and August 19, 1963, Grosvenor Lake sam-
ples (fig. 9). It appears that in those areas where
insects are heavily utilized by older pygmy white-
fish, the diet shift of fish from zooplankton to in-
sects occurs late during the first summer of life.
Eschmeyer and Bailey (1955) found copepods to

be the dominant food of age 0+ pygmy whitefish
from Lake Superior in September.

DIEL VARIATIONS IN DIET

The sample of age 1+ and older fish from
Brooks River on August 24-25, 1963 (table 8),
was collected from the same riffle area at four ad-
jacent 6-hour intervals to determine diel differ-
ences in quantity and quality of foods eaten. No
significant difference in the composition of diet
items was found throughout the 24-hour period;
however, the average volume of food material per

570

U.S. FISH AND WILDLIFE SERVICE

stomach was three times as great at midday as at
midnight (fig. 10). The most intense feeding
period during this 24-hour period apparently was
during daylight hours and not during darkness.

COMPARISONS OF GROWTH AND DIET

By comparing the dramatically different
growth rates and sizes that pygmy whitefish at-

100

< _

O z
I- HJ

en o

w " 50

2 </>

=> K

_I Z

O UJ

> K

< o 25

■ insects

r~l ZOO PLANKTON
I I OTHER

JULY II, 1963 I SEPTEMBER
26, 1962
SOUTH BAY

AUGUST

14, 1962

BROOKS

LAKE

AUGUST 19,1963

GROSVENOR
LAKE

Figure 9. — Percent of total volume of stomach contents
of age 0+ pygmy whitefish by major food categories.

0.8

z
o

0.7

0.6

0.4

uj 0.3

0.1

0.0

N = I5

N=I5

N=ie

1800 2400

AUGUST 24

0600 1200

AUGUST 25

Figure 10. — Variation by time of day in mean volumes of
stomach contents of 63 pygmy whitefish caught at 6-
hour intervals from the same area in Brooks River,
August 24 and 25, 1963.

tain in the Naknek system (figs. 2 and 6) with the
differences in diet, a strong positive correlation
between size of fish and utilization of insects be-
comes apparent. An analysis was made by first
grouping all contents from each sample into three
categories (insects, zooplankton, and other), then
grouping the samples according to the relative im-
portance of insects and zooplankton. Three rather
distinct groups of samples resulted: one with
heavy, one with moderate, and one with almost no
insect utilization. These grouped samples com-
pared with the largest known pygmy whitefish
from the same grouped areas (fig. 11) illustrate
the correlation between insect utilization and size.
Maximum size is not the only index, because the
general ranges of length frequencies from different
parts of the system (table 7) fall into the same
groupings. If this correlation is biologically
valid, it raises a question as to why Brooks Lake
pygmy whitefish do not eat insects. Merrell
(1964) has shown that other Brooks Lake fishes
utilize insects, which indicates their general avail-
ability. No comparative data are available, how-
ever, on differences in insect populations in the
Naknek system.

Preference for, access to, or utilization of spe-
cific foods may not directly account for differences
in growth rates of pygmy whitefish populations
in Brooks Lake and South Bay-Iliuk Arm. Basic
differences in ecological characteristics of the areas
such as morphometry, limnology, productivity,

SOUTH BAY NORTH ARM
BROOKS RIVER HAMMERSLY
ILIUK ARM GROSVENOR LAKES

BROOKS LAKE
N = 96

N=250 N=50

tot ^

/Hfr~""x

I I 1 ^

//\l \

v V

I63MM II5MM

84MM.

■i INSECTS

I 1 ZOOPLANKTON

1 1 OTHER

Figure 11. — Relative importance of insects, zooplankton,
and other foods in diet of pygmy whitefish from three
areas of Xaknek system. Data based on percent of
sample volumes shown in table 8. Number beneath
each figure represents largest pygmy whitefish collected
from the grouped area.

PYGMY WHITEFISH OF SOUTHWEST ALASKA

571

species combinations of fishes, and food organisms
are interwoven in a complex of relations that re-
sult in distinctly different environments. Differ-
ences in growth rates, longevity, and food habits
of pygmy white-fish in the Naknek system prob-
ably reflect adaptive responses to these overall en-
vironmental differences and not simply the avail-
ability or use of certain food items.

The differences we found in Prosopiwm coulteri
populations in Brooks Lake and South Bay-Iliuk
Arm parallel the differences in Coregomi-s peled
(Gmelin) populations in the Swedish lakes Vjom-
sjon and Uddjaur-Storavan (Lindstrom and Nils-
son, 1962). In Sweden, 0. peJ-ed was a slow-grow-
ing plankton feeder in Lake Vjomsjon and a fast-
growing insect feeder in Lakes Uddjaur-Storavan.
As previously discussed, P. coulteri is a slow-grow-
ing plankton feeder in Brooks Lake and a fast-
growing insect feeder in South Bay-Iliuk Arm.
Lake Vjomsjon had fewer associated whitefish
species, proportionately less littoral area, and
probably lower productivity than Lakes Uddjaur-
Storavan. In the Naknek system, Brooks Lake
has fewer associated whitefish species, less littoral
area, and lower productivity than South Bay-
Iliuk Arm. The observed plasticity of the genus
Prosopiwm in response to environmental differ-
ences in the Naknek system is similar to that
widely recognized in coregonid and leucichthid
whitefishes (Walters, 1955; Svardson, 1957; and
others) . The variability in meristics and morphol-
ogy found in pygmy whitefish by McCart (1963)
also emphasizes this plasticity in Prosopiwm.

REPRODUCTION

Data on pygmy whitefish reproduction were
collected from various areas as follows: sex ratio
and age and size at maturity — South Bay and
Brooks Lake; fecundity — South Bay, Brooks
Lake, and North Arm; and seasonal maturation
and spawning behavior — South Bay and Brooks
River.

SEX RATIOS

Only a few large sampler from Brooks Lake and
South Hay were processed for sex ratios, but they
revealed nearly equal ratios ((able !>). The largest
specimens were almost always females (table 7),
a phenomenon undoubtedly due to the greater
longevity and the faster growth rate of females.

These larger females, however, constituted a nu-
merically minor segment of the population. Esch-
meyer and Bailey (1955) and McCart (1963) also
found females to be the oldest and largest fish in
their collections.

Table 9. — Sex ratios of pygmy whitefish, Brooks Lake and
South Bay, collected during the summers 1961-62

Location and date

Brooks Lake:

Aug. 7, 1961.

June 29, 1962
South Bay:

July 23, 1962.

Aug. 24, 1962

Sex ratio

females to

males

1:0.92
1:1.08

1:1. 13

1:0.82

AGE AND SIZE AT MATURITY

The degree of maturity in age groups I and II
varied between lake populations and between
sexes within a single population (table 10). In
Brooks Lake 10 percent of the females and 36 per-
cent of the males reached sexual maturity during
their second growing season (age 1+ ). In South
Bay no females and only 2 percent of the males
matured as age 1+ fish. In both lakes more than
95 percent of the age 11+ fish and all of the older
fish were mature.

Table 10. — Age at maturity of pygmy whitefish collected
during the summer and fall from Brooks Lake and South
Bay, 1961-62

Brooks Lake

South Bay

Males

Females

Males

Females

Age

Fish

sample

Ma-
ture

Fish

sample

Ma-
ture

Fish

sample

Ma-
ture

Fish

sample

Ma-
ture

Num-
ber
67
28
2

Per-
cent
36
96
100

Num-
ber
58
96
11

Per-
cent
10
97
100

Num-
ber
160
214
14
4

Per-
cent
2
99
100
100

Num-
ber
175
181
16
12
2

Per-
cent
0

11+

III+

100

JV+ .

100

In Brooks Lake and South Bay, only a slight
tendency exists for males to mature at a smaller
size than females. In contrast, Eschmeyer and
Bailey (1955) found 100 percent of the males ma-
ture at sizes smaller than the smallest mature
females. Because of the great differences in
growth rates in the Naknek system, there is no
overlap in the size at maturity between Brooks
Lake and South Hay pygmy whitefish (table 11).

572

U.S. FISH AND WILDLIFE SERVICE

Table 11. — Size at maturity of pygmy whitefish collected
during the summer and fall from Brooks Lake and South
Bay, 1961-62

1,200

Brooks Lake

South Bay

Length

Males

Females

Males

Females

Fish

sample

Ma-
ture

Fish

sample

Ma-
ture

Fish

sample

Ma-
ture

Fish

sample

Ma-
ture

Mm.
44-46

ATu??i-
ber
10
35
81
73
28
25
18
13
3
3

Per-
cent
0
0
0
8
29
76
94
100
100
100

Num-
ber

Per-
cent

Num-
ber

Per-
cent

Num-
ber

Per-
cent

47-49

72
71
29
19
24
26
22
36
20
4
2

0
0
0
3

21
71
96
100
100
100
100
100

50-52

53-55

56-58

59-61

17
69
121
256
237
151
45
9

62-64

65-67 .-

105

185

207

126

0
0
0
0
0
0
2
5
20
0

0
0

68-70 .

71-73...

74-76

77-79

80-82

83-85

86-88

95-97

98-100

100
94
100
98
100
100
100
100
100
100
100
100
100

100

101 103

100

107-109

110-112

113 115

100

119-121

100

122-124

100

125-127

100

128-130

100

131-133

100

134 136

100

137 139

100

146-148

5
1

100

161 163

100

FECUNDITY

The total number of maturing eggs in pygmy
whitefish ovaries were counted for 59 fish from
South Bay, 19 from Brooks Lake, and 7 from
North Arm. The number of eggs ranged
from 103 to 1,153 per female. Body length-
fecundity equations comjmted for each sample
showed some difference between areas. However,
a single equation was determined (fig. 12) by
grouping all 85 females, because there was no
overlap in the size range of females between
samples.

The salient features of these fecundity data are
(1) that a broad range of fecundities exists in
different parts of the system and (2) that pygmy
whitefish from the Naknek system are consider-
ably more fecund than the same size fish from
Lake Superior. We transformed the total length-
fecundity relation given by Eschmeyer and Bailey
(1955) into a fork length-fecundity relation for
comparison with our data. A 120-mm. female

PYGMY WHITEFISH OF SOUTHWEST ALASKA
795-353 O — 66 i

2.9552*2.7513 1 09 L

_L_

_L-

90 100 110 120
FORK LENGTH (MM.)

130 140 150

Figure 12. — Length-fecundity relation of pygmy white-
fish from three areas of Naknek system. Equation
derived by combining data from the three areas.

from Lake Superior (130 mm. total length) aver-
aged about 4-40 eggs, while the same size female,
from the Naknek system averaged about 580 eggs.
These differences in fecundity could be adaptive
responses of the various populations to different
environmental conditions that produce higher or
lower survival opportunities for the species
(Svardson, 1949; Nikolsky, 1963).

SPAWNING SEASON AND BEHAVIOR

Egg size in maturing females from South Bay
in 1962 increased markedly between late summer
and the fall spawning period. Egg diameters
that averaged 1.1 mm. in early August increased
to 2.4 mm. in ripe females in early November,
while ovary weight increased from 3.5 to 16.5 per-
cent of the total body weight (fig. 13). Egg size
and ovary weight relative to body weight in near
ripe fish from Lake Superior (Eschmeyer and
Bailey, 1955) were 2.0 mm. and 15 percent.

Spawning of pygmy whitefish in Brooks Lake
and South Bay in 1962 and 1963 apparently oc-
curred between mid-November and mid-Decem-
ber. Mature, ripe males and females from South
Bay were collected near the mouth of Brooks
River on November 7 and 9, 1962. The water
temperature in South Bay on November 9, 1962,
was 3.9° C. Both eggs and sperm could easily be
extruded by exerting slight pressure on the abdo-
men, and females as well as males were tuberculate
over much of the body. The ventral fins of both
sexes were orange. Pygmy whitefish from
Brooks Lake on November 7, 1962, were not quite

573

O MATURING NONRIPE EGGS
• RtPE EGGS

ClO

•_

_l I I I L.

_l I I I I I I I I l_

5 10 15 20 25 301 5 10 15 20 25 3015 10 15 20 25 301 5 10 15 20 25 30
AUGUST SEPTEMBER OCTOBER NOVEMBER

Figure 13. — Seasonal maturation of pygmy whltefish col-
lected from South Bay, 1962. Average egg diameter
based on minimum of 10 eggs per female. N equals
number of females examined.

as ripe as those from South Bay. Although ma-
ture fish taken in South Bay on October 29 and
November 5, 1063, were not quite ripe, three speci-
mens taken from Brooks River on the night of
November 6 apparently were, because sex products
could be readily extruded from them.

The spawning period in the Naknek system
agrees with most other spawning information on
pygmy whitefish. The time of spawning in Lake
Superior (Eschmeyer and Bailey, 1955), Glacier
National Park, Mont. (Schullz, 1941), and four
British Columbia lakes (McCart, 1963) was be-
lieved to be in November or December. The
November-December spawing in the Naknek sys-
tem compares closely with the supposed time of
spawning in Lake Superior and Glacier National
Park, Mont. (Eschmeyer and Bailey, 1955; and
Schultz, 1941). Weisel and Dillon (1954) col-
lected sexually mature and spent pygmy whitefish
from Bull Lake between December 26 and Janu-
ary 12. Kendall (1917 and 1021) reported on six
pygmy whitefish collected from the Chignik River
system. Alaska, about November 1, 1912. These
fish (Kendall, 1921) were "mature individuals
ready to spawn," which agrees with the other
known spawning times of this species.

Exceptions to the late fall and winter spawning
of pygmy whitefish have been noted. Kendall
(1921) reported thai sonic pygmy whitefish col-
lected on July 20, L909, and August 2, L912, from
the outlel of Lake Aleknagik were in breeding

condition. Apparently the collector of one of
these samples reported that pygmy whitefish were
passing out of Lake Aleknagik in large numbers,
and Kendall interpreted this as a spawning run.
We question the validity of this interpretation and
doubt that a spawning migration was occurring as
early as July 20 or August 2, although individual
specimens might have seemed ready to spawn.
McCart. (1963) found a physiologically atypical
female in Cluculz Lake, British Columbia, on
July 15, 1962, which appeared to be ripe. We ex-
amined pygmy whitefish collected on July 13, 1963,
from Wood River just below the outlet of Lake
Aleknagik by Dr. R. L. Burgner of the Fisheries
Research Institute, University of Washington, and
found the condition of the gonads to be 3 or 4
months from full maturity. Two of the AVood
River females had average egg diameters of 1.0
mm., and the ovaries made up only 2.7 percent
of the body weight (fig. 13). Burgner (personal
communication) reports that large numbers of
pygmy whitefish can be seen throughout much of
the summer in Wood River below Lake Aleknagik.
These observations and Kendall's (1921) comments
on fish passing out of the lake could represent the
seasonal feeding movements of a lake population
similar to that observed during the summer in
South Bay and lower Brooks River. Pygmy white-
fish may spawn below Lake Aleknagik, but prob-
ably later than Kendall believed.

Although specific details of spawning behavior
were not observed, we determined that pygmy
whitefish (in Brooks River at least) spawn only
at, night, as do mountain whitefish in Montana
(Brown, 1952). Routine underwater surveys in
early November in 1962 and 1963 revealed no
pygmy whitefish in Brooks River during daylight
hours, although large numbers of ripe or nearly
ripe fish were known to be in South Bay off the
river mouth. On a dive just after dusk on Novem-
ber 5, 1963, divers using underwater hand lamps
observed that a few large pygmy whitefish had
moved into lower Brooks River from South Bay.
Between 20 and 25 pygmy whitefish were observed
in the same area the following night about 3 hours
after darkness. These fish probably represented
the beginning of the spawning run in 1963.

South Bay fish probably remain in the lake in the
vicinity of Brooks River until they reach full
maturity, when they move into the river at night

574

U.S. FISH AND WILDLIFE SERVICE

to spawn. Periodic observations along the stream-
hank at night with a lantern in late November and
early December in 1963 continued to reveal the
presence of pygmy whitefish in the stream. Un-
seasonably cold temperature, however, caused ice
conditions that precluded intensive observations.
About 100 fish were seen just at the mouth of
Brooks River during a night dive on December
16, 1963. Most of these fish were individually
scattered over the stream bottom, although one
congregation of 8 to 10 fish may have represented
a spawning group. These particular fish darted
wildly about upon encountering the underwater
spotlight. The water temperature in Brooks River
on December 16 was 0.3° C. All adult pygmy
whitefish taken in gill nets under ice in South Bay
near the river mouth on December 12 and 18 were
spent.

DISCUSSION

In the Naknek River system pygmy whitefish
apparently reach their greatest density in Brooks
Lake where they may be the most abundant species
in the lake. These conclusions are based on the
combined numbers of each species caught in all
sampling gears from 1961 to 1963. In Brooks
Lake, South Bay, and Iliuk Arm, pygmy white-
fish are commonly associated with juvenile sock-
eye salmon. This relation merits consideration be-
cause of the commercial value of the Naknek
River system sockeye salmon.

Although the association of two species prede-
termines some sort of interspecific relation, in fishes
it is usually difficult to determine the exact nature
of this relation. Larkin (1956), who considered
competition in a concise limited sense, points out
that competition itself is difficult to separate from
other complex interrelations between fish species.
Rogers (1961), after carefully considering the
diets of young-of-the-year sockeye salmon and
three age groups of threespine sticklebacks collect-
ed from similar ecological areas of Wood River
Lakes, could only conclude that "potential food
competition exists." Greenbank and Nelson
(1959), in studying the threespine stickleback in
Karluk Lake, conclude that "Quantitative infor-
mation is insufficient to assess accurately the bene-
fit or harm to salmon production caused by the
stickleback population." Johnannes and Larkin
(1961) could demonstrate -severe competition be-

tween redside shiners (Richardxonius balteatus)
and rainbow trout for amphipods in Paul Lake,
British Columbia, only because of long-term data
that included preshiner amphipod densities along
with feeding habits and growth rates of the trout.

In the present study it is impossible on the basis
of existing data to demonstrate direct interspecific
competition in any form between pygmy white-
fish and juvenile sockeye salmon or other white-
fishes. It is possible, however, that the combined
effects of interspecific and intraspecific relations
of these species may influence the growth and
general well-being of each in various parts of
the Naknek system. Although McCart (1963)
could not demonstrate direct competition between
pygmy whitefish and other whitefishes, he found
indications of interactive segregation between
whitefishes which resulted in differences in depth
distribution and growth rates. He also noted that
the large Mac Lure and McLeese Lake pygmy
whitefish were the only ones in British Columbia
that did not coexist with another species of the
genus Prosopiwm. In the present study the largest
pygmy whitefish were found in South Bay and
Iliuk Arm where three other whitefishes occur
(round and humpback whitefish and least cisco),
while the smallest pygmy whitefish were found in
Brooks Lake where round whitefish is the only
other whitefish. Although growth rates of pygmy
whitefish in the Naknek system are correlated with
different diets, McCart (1963) found no differences
in diets of this fish in four lakes where growth was
quite different.

Both pygmy whitefish and juvenile sockeye sal-
mon feed heavily on zooplankton in Brooks Lake,
although Merrell (1964) points out that during
late spring and early summer, insects may be the
most important item in the diet of Brooks Lake
sockeye salmon (age 1+ and older) . Even though
differences in the production of sockeye salmon
smolts in Brooks Lake have varied from 60,000 to
360,000 during recent years, there has been little
difference in the mean size of age 1+ smolts. This
suggests that densities of young salmon, together
with other environmental influences such as poten-
tially competitive dense populations of pygmy
whitefish, have not altered the basic growth rate of
sockeye salmon in Brooks Lake.

Interspecific association of juvenile sockeye sal-
mon and pygmy whitefish in South Bay and Iliuk

PYGMY WHITEFISH OF SOUTHWEST ALASKA

575

Arm is complicated by several factors. First, a
greater number of other associated species occur
in these areas than in Brooks Lake. Second, in
addition to serving as primary rearing areas for
salmon produced in adjacent spawning areas such
as Brooks River and M argot Creek (a tributary
of Iliuk Arm), both South Bay and Iliuk Arm, of
necessity, serve as migration lanes for salmon
produced in upsystem areas. This point is further
complicated by interlake movement whereby some
juvenile sockeye salmon begin their nursery lake
existence in upstream lakes (i.e. Coville and
Brooks), then migrate into downstream nursery
areas (i.e. Iliuk Arm and South Bay) to complete
their first year of life.5 Tims, the juvenile, sockeye
salmon populations in South Bay and Iliuk Arm
are frequently undergoing dramatic changes in
density apart from normal fluctuations in the local
population. Although pygmy whitefish feed
primarily on insects in South Bay and Iliuk Ann,
the diet of young sockeye salmon in these areas is
not known. It may be that no possible food com-
petition exists between these species in South Bay
and Iliuk Arm.

The reasons for the marked differences in the
biology of pygmy whitefish populations in Brooks
Lake and South Bay are poorly understood.
Pygmy whitefish in Brooks Lake grow slower,
mature earlier, and live shorter lives than those in
South Bay or Iliuk Arm. Consequently, spawn-
ing females are younger, significantly smaller, and
less fecund in Brooks Lake. Yet, the species is
extremely successful in Brooks Lake, as evidenced
by abundance. Factors contributing to this suc-
cess undoubtedly deal with lower mortalities from
fertilized egg; to maturity. Because of early matu-
rit v, short life span, and small size, pygmy white-
fish in Brooks Lake fit the concept of a "dwarfed
or small form" discussed by Svardson (1957),
Aim (1959), and Fenderson (1964). As pointed
out by Aim, a "dwarfed form" with short life and
early maturity is distinct from a slow-growing
"normal fonn" which has greater longevity and
matures at an older age but still at a small size.
Dwarfism may provide a species with advantages

^'Summary report of studies "ti the optimum escapement of
sockeye salmon in southwestern Alaska, 1961—62. Prepared by
the Bureau of Commercial Fisheries Biological Laboratory. Aula*
Bay, Alaska, and Fisheries Research Institute, University of

Washington, Spattlc ( Manuscript on tile at tin- BCF Laboratory.)

in survival and competition ( Lindstrom and Nils-
son, 1962; McCart, 1963; and Fenderson, 1964).

On the basis of recent data from Lake Alek-
nagik and Chignik Lake, Peter J. McCart (per-
sonal communication) believes that two distinct
sub-populations of pygmy whitefish may occur
sympatrically in these lakes. One form, which is
generally larger, is a river-oriented insect feeder
with low gill raker counts and is apparently con-
fined to shallow water. The other form is a lake-
oriented plankton feeder with high gill raker
counts and inhabits deep water. These criteria, in
part, apply to some of the differences found in
populations in the Naknek system. This is partic-
ularly time with the insect feeders in South Bay
where the population is strongly oriented to
Brooks River and the relatively shallow waters of
South Bay. In other parts of the system, however,
differences in ecological distribution represent
exceptions to this general scheme. In Iliuk Arm,
large fast-growing insect feeders occur from shal-
low beaches to maximum depths of 168 m., whereas
in Brooks Lake, slow-growing insect feeders occur
from the shallow to the deepest depths. Although
we have not studied meristic variation of popula-
tions of pygmy whitefish in the Naknek system in
detail, the insect feeders in South Bay and Brooks
River have lower gill raker counts than the plank-
ton feeders in Brooks Lake. Eschmeyer and
Bailey (1954, p. 174) point out that gill rakers
from pygmy whitefish in rivers, or lakes domi- ,
nated by rivers, tend to be fewer in number and
shorter in length than those from lacustrine en-
vironments. Whether differences found in popu-
lations of pygmy whitefish in the Naknek system
represent genetically distinct subpopulations or
the adaptive, responses of the species in utilizing
the many environments present in the system can-
not be determined without additional study.

Differences in diet in various parts of the system
have been discussed and correlated with growth
rates. Actually, growth rates are correlated not
only with the degree of insect utilization but also
with the rate of phytoplankton productivity in
various areas. Primary productivity is relatively
high in South Bay and Iliuk Ann, low in Brooks
Lake, and intermediate in North Arm and Gros-
venor Lake.6 A notable exception to correlating
growth rates of pygmy whitefish with primary

576

* Sep footnote 2 on p. 557.

U.S. FISH AND WILDLIFE SERVICE

productivity is that Coville. Lake, which has the
shallowest mean depth, the highest water tempera-
tures, and the highest primary productivity in the
system, apparently has only a small population of
intermediate size pygmy whitefish; however,
Coville Lake may have denser populations of other
species (i.e. pond smelt, humpback whitefish, and
juvenile sockeye salmon) than other parts of the
system.

Until comparative data are available on the
relative abundance of various food groups and
the diets of associated fishes in different areas, it is
impossible to determine the role of food availabil-
ity or preference for specific foods in evaluating
differences in the biology of pygmy whitefish in
the Naknek system. Rather than simple differ-
ences in diet, growth, or ecological distribution, we
feel the dramatic differences found in pygmy
whitefish populations in the Naknek system prob-
ably reflect widely varying adaptive responses of
a highly plastic species to the complex of environ-
mental differences found throughout the system.

SUMMARY

The pygmy whitefish has the greatest discontin-
uous distribution of any fresh-water fish in North
America, occurring in the Atlantic, Pacific, and
Arctic Ocean drainages. It is widely distributed
and locally abundant in lakes of the Naknek River
System in southwest Alaska.

More than 10,000 pygmy whitefish were collected
from the Naknek system with seines, otter trawls,
tow nets, and gill nets from 1961 to 1963. This
species seems to have a prominent role in the dy-
namics of some Naknek system fish populations.

In the Naknek system, pygmy whitefish occur
in all benthic areas from shallow littoral depths
to the deepest areas available. Seasonally, in cer-
tain age groups and in certain areas, they occur
in limnetic waters of lakes and in streams.

Nineteen species, including the closely related
round whitefish, occurred in catches with pygmy
whitefish in various parts of the Naknek system.

Polynomial equations were used to express the
curvilinear relation between body length and an-
terior scale radius. Body length at scale formation
is about 25 mm.

The oldest and largest fish from the two areas
studied most intensively was an age V 163-mm.
female from South Bay and an age III 84-mm.

female from Brooks Lake. Length frequency dis-
tributions from other areas were intermediate be-
tween these extremes. Calculated and observed
growth indicated that growth was much greater
in South Bay than in Brooks Lake. Both sexes
in Brooks Lake showed a tendency to mature at an
earlier age than in South Bay.

Dipteran insects were the principal foods eaten
by pygmy whitefish in South Bay. Crustacean
plankton dominated their diet in Brooks Lake.
In other areas insect and zooplankton foods were
about equal in importance. In areas where insects
were important in the diet of older fish, the shift
from zooplankton to insect foods in age 0+ fish
began during the first summer of life. A positive
correlation between growth and insect utilization
was found.

The fork length-fecundity relation of Naknek
system pygmy whitefish is expressed by the equa-
tion

Log E= -2.9552+2.7513 log L.

where E equals number of eggs per female and L
equals fork length of the fish. Fecundity in Nak-
nek system fish exceeds that in Lake Superior fish.

Spawning occurs in November and December.
South Bay fish move into Brooks River for spawn-
ing only at night. Eggs in ripe fish from South
Bay averaged 2.4 mm. in diameter, and the ovaries
were 16.5 percent of the body weight.

Potential interspecific competition exists be-
tween pygmy whitefish and juvenile sockeye
salmon, particularly in Brooks Lake where foods
are similar and the whitefish are numerous.

Slow growth, low fecundity, and short life
characterize Brooks Lake pygmy whitefish.
These factors must be compensated for by lower
mortality from fertilized egg to maturity than in
the South Bay population, which is characterized
by fast growth, higher fecundity, and longer life.

The wide range in growth rate, fecundity, lon-
gevity, and diet of populations of pygmy white-
fish in the Naknek system is probably due to the
adaptive responses of a highly plastic species to
the variety of environmental characteristics, such
as water quality and clarity, drainage geology,
phytoplankton productivity, lake morphometry,
fish species, and food organism associations found
in different parts of the system.

PYGMY WHITEFISH OF SOUTHWEST ALASKA

577

ACKNOWLEDGMENTS

Many persons helped collect specimens for this
study, particularly Robert Dewey, resident biol-
ogist, at the Brooks Lake Field Laboratory.
Donald Bevan of the Fisheries Research Institute
made arrangements for the computer analysis and
derivation of body length-scale length equations.
Charles J. DiCostanzo of the Bureau of Com-
mercial Fisheries provided helpful guidance on
the use of these equations, and Charlotte Heard
counted the eggs in ovaries for the fecundity data.

LITERATURE CITED

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1959. Connection between maturity, size and age in
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Baldwin, Wayne J.

1961. Construction and operation of a small boat
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Brown, C. J. D.

1952. Spawning habits and early development of the
mountain whitefish, Prosopium williamsoni, in
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Burgner, Robert L.

1960. Study of population density and competition
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Carl, G. Clifford, W. A. Clemens, and C. C. Lindsey.
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Eschmeyer, Paul H.. and Reeve M. Bailey.

1955. The pygmy whitefish, Coregonus coulteri, in
pake Superior. Trans. Amer. Fish. Soc. 84 : 161-
199.
Fenderson, Owen C.

1964. Evidence of suhpopulations of lake whitefish,
Coregonus clupeaformis, involving a dwarfed form.
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Greenbank, John, and Philip R. Nelson.

1959. Life history of the threespine stickleback,
Gasterosteus aculeatus Linneaus, in Karluk Lake
and Bare Lake. Kodiak Island, Alaska. U.S. Fish
Wildl. Serv.. Pish. Bull, 59:537-559.
Heard, William R.

1962. The use and selectivity of small-meshed gill
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Johannes, R. E., and P. A. Labkin.

1961. Competition for food between redside shiners
( Richwrdsonius balteatus) and rainbow trout

(Salmo gairdneri) in two British Columbia Lakes.
J. Fish. Res. Bd. Can. 18(2) : 203-220.
Johnson, W. E.

1956. On the distribution of young sockeye salmon
(Oncorhynchus ncrka) in Babine and Nilkitkwa
Lakes, B. C. J. Fish. Res. Bd. Can. 13(5) : 695-708.

Karlstrom, Theodore X. V.

1957. Tentative correlation of Alaskan glacial
sequences. 1956. Science 125(3237) : 73-74.

Kendall, William C.

1917. A second record for the Coulter's whitefish
(Coregonus coulteri Eigenmann). Copeia 1917
(45) : 54-56.
1921. Further observations on Coulter's whitefish
(Coregonus coulteri Eigenmann). Copeia 1921
(90) : 1-4.
Krogius, F. V.. and E. M. Krokhin.

1948. Ob urozhainosti Molodi Krasnoi (Oncorhyn-
chus nerka Walbaum). [On the production of
young sockeye salmon (Oncorhynchus nerka Wal-
baum).] Izv. Tikhook. Xauch.Tssledovatel. Inst.
Rybn. Khoz. Okeanogr. 28:3-27. [Fish. Res. Bd.
Can., Transl. Ser. 109, 1958.]
Larkin, P. A.

1956. Interspecific competition and population con-
trol in freshwater fish. J. Fish. Res. Bd. Can.
13(3) : 327-342.
Lindstrom, Thorolf, and Nils-Arvid Nilsson.

1962. On the competition between whitefish species.
In E. D. LeCren and M. W. Holdgate (editors).
The exploitation of natural animal populations,
p. 326-340. John Wiley and Sons, Inc., New York.

McCart, Peter J.

1963. Growth and morphometry of the pygmy white-
fish (Prosopium coulteri) in British Columbia.
M.S. Thesis, Univ. Brit. Columbia, Vancouver,
97 p.

Merrell, Theodore R., Jr.

1964. Ecological studies of sockeye salmon and re-
lated limnological and climatological investiga-
tions, Brooks Lake, Alaska, 1957. U.S. Fish Wildl.
Serv., Spec. Sci. Rep. Fish. 456, 66 p.

Meyers, George S.

1932. A new whitefish, Prosopium- snyrieri, from
Crescent Lake, Washington. Copeia 1932(2) :
62-64.
Muller, Ernest Hathaway.

1952. The glacial geology of the Naknek district,
the Bristol Bay region, Alaska. Ph. D. Thesis.
Univ. 111., Urbana, 98 p.
Nikolsky, G. V.

1963. The ecology of fishes. Academic Press, New
York, 352 p.
Rogers, Donald E.

1961. A comparison of (be food of red salmon fry
and threespine sticklebacks in the Wood River
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Rounsefbll, George A., and W. Harry Everhart.

1053. Fishery science its methods and applications.
John Wiley and Sons, Inc., New York, 444 p.
Schultz, Leonard P.

1936. Keys to the fishes of Washington, Oregon and
closely adjoining regions. Univ. Wash.. Puhl. Biol.
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U.S. Fish Wildl. Serv., Cons. Bull. 22, 42 p.
Snyder, J. O.

1817. Coulter's whiteflsh. Copeia 1917(50) : 03.

SVARDSON, GUNNAR.

1049. Natural selection and egg number in fish.

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Walters, Vladimir.

1055. Fishes of western Arctic America and eastern
Arctic Siberia. Bull. Anier. Mus. Natur. Hist.
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Weisel, George F., and John B. Dillon.

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1054(2) : 124-127.
Wynne-Edwards. V. C.

1047. The Yukon Territory. In North West Ca-
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PYGMY WHITE FISH OF SOUTHWEST ALASKA

579

A REVIEW OF WESTERN ATLANTIC CAT SHARKS, SCYLIORHINIDAE, WITH
DESCRIPTIONS OF A NEW GENUS AND FIVE NEW SPECIES

By Stewart Springer, Fishery Biologist (Research)

Bureau of Commercial Fisheries Ichthyological Field Station

Stanford, Calif.

ABSTRACT

A new genus Schroederichthys is described, together
with its type species Schroederichthys maculatus from
the western Caribbean and a second species
Schroederichthys tenuis from the Atlantic off Brazil.
Scyliorhinus meadi from the east coast of Florida,

Scyliorhinus hesperius from the western Caribbean,
and Galeus cadenati from the vicinity of Panama are
also described. All 15 of the known western Atlantic
species are illustrated, and species characters thought
to be of value for revisionary studies are noted.

The purpose of this paper is to review the west-
ern Atlantic cat sharks with especial attention to
description of those characteristics of genera and
species that are of interest for a revision of the
cat sharks of the world ; and also to describe new
material collected by exploratory fishing vessels
of the Bureau of Commercial Fisheries in the
western Atlantic, including representatives of a
new genus and five new species.

For a revision of the family, more material
should be examined than is now available in
American museum collections. The distinctions
between the genera 8cyliorhinus and Halaelurus,
for example, appear to be somewhat superficial,
but a revision of generic arrangement is imprac-
tical without a survey of all known species and the
use of a greater number of diagnostic characters
than can be gleaned from the terse and noninform-
ative descriptions of many of the nominal spe-
cies. A family revision which is in progress will
provide a better opportunity for treatment of
genera.

SOURCES OF MATERIAL

Collections of cat sharks made by the Bureau of
Commercial Fisheries exploratory fishing vessels,

Note. — Approved for publication July 9, 1965.

Oregon, Silver Bay, and Combat, are the princi-
pal source of material for this report. Studies of
these collections were supplemented by examina-
tion of the relatively small numbers of cat sharks
in the U.S. National Museum, the Museum of
Comparative Zoology at Harvard College, and the
Natural History Museum of Stanford University.
An important series of Apristuri/~s in the Museum
of Comparative Zoology collected by the CajPn
Bill II, a fishing vessel chartered by the Woods
Hole Oceanographic Institution, was examined.
For purposes of comparison, an excellent series of
the Pacific species, Aprisherus brunnev-9 (Gilbert)
was assembled from specimens collected from the
research vessels of the University of Washington
College of Fisheries and by the exploratory vessel
John N. Cobb of the Bureau of Commercial Fish-
eries. Similarly a young example of Cephalo-
scyTlivmb uter (Jordan and Gilbert) and also a
series of the Pacific cat shark Parmaturus xanmrus
(Gilbert) were obtained for comparison with At-
lantic scyliorhinids from collections made by the
research vessel N. B. Scofield of the California
Department of Fish and (Tame. The type of
Scylliv/m laurusmnii Saemundsson was loaned by
the Natural History Museum, Reykjavik. Iceland,
for examination.

FISHERY BULLETIN! VOLUME 65, NO. 3

581

No specimens from the coast of Argentina were
seen. Halaelurus Mvius (Smith) has been re-
corded from Argentina by Berg (1895), Lahille
(1921, 1928), and Norman (1937). Halaelurus
chUensis (Guichenot) mentioned by Lahille
(1928) as a synonym of Halaelurus Mvius
(Smith) probably is a valid species and two spe-
cies referrable to Halaelurus occur in Argentine
waters according to information received from
Professor Elvira M. Siccardi (personal communi-
cation). Professor Siccardi also found a popula-
tion of Scyliorhinus on the coast of Argentina,
either S. boa (Goode and Bean) or an undescribed
species very similar to S. boa. Species found on
the coast of Argentina are given very brief treat-
ment here, based chiefly on photographs, measure-
ments, and records of specimens that Professor
Siccardi has kindly allowed me to see. Illustra-
tions in this paper of Halaelurus are of specimens
from Chile in the collection of the U.S. National
Museum.

Ideal study series, that is, series including adults
of both sexes, young in various states of growth,
and specimens collected from a number of locali-
ties sufficient to outline the probable limits of
geographical and vertical distribution, are not
available for any of the 15 species treated here.
For example : available specimens of ScyUorhinus
retifer (Garman) satisfy ideal requirements
except that no adult females with eggs have been
examined; the series of Apristurus riveri Bigelow
and Schroeder includes two adult males and three
adult females, one with a partly extruded egg case,
and a few young examples, material sufficient to
show sexual dimorphism in the teeth of the adults
and to show the oviparous habit, but the series
lacks immature males.

Family SCYLIORHINIDAE

The definition of the family given by Bigelow
and Schroeder (1948, pp. 195-196) is followed
provisionally. Separation of the cat sharks from
members of the family Orectolobidae on the basis
of external form is comparatively simple when
dealing witli American material. No Atlantic
American cat shark has barbels or has the nostrils
connected with the mouth by a groove, while
orectolobids in general have these characteristics.
One Indian ( )cean genus, C onoporodernia , referred
to Scyliorhinidae by Bigelow and Schroeder, has
barbels and another, HaploolepTuirus, does have

the nostrils connected with the mouth by a groove.
Otherwise the use of these characters to separate
the Scyliorhinidae from the Orectolobidae is the
most practical one. Of the characters given by
Bigelow and Schroeder for separartion of the two
families, Orectolobidae and Scyliorhinidae (1948,
pp. 178 and 195), the only characterization of the
Scyliorhinidae always applicable is that the
scyliorhinids have three rostral cartilages, united
at their tips; whereas orectolobids have none, one,
or three rostral cartilages which are small and, if
present, are not united at their tips. I have veri-
fied this only in a few western Atlantic species.
Even tooth characters do not hold unless excep-
tions are noted. Adult males of Apristurus riveri
Bigelow and Schroeder, instead of having small
teeth with several cusps as in all other known
scyliorhinids including female ^4. riveri, have
single cusped teeth in about 20 median rows.

Grace White (1936), commenting on forms
generally known as cat sharks, states that varia-
tion in the catuloids (cat sharks and allied groups)
is so extreme as to make the distinction even among
genera difficult. Certainly it is difficult to find
family characteristics to which there are no excep-
tions and which set off scyliorhinids sharply from
obviously related families. Although there has
been reasonably general agreement on the kinds of
sharks constituting the group known by the
common name cat shark, precise morphological
definitions of the family or families constituting
the cat sharks and their allies have been various
and apparently not entirely satisfactory even to
those proposing the definitions. The cat sharks
are, with few exceptions, small demersal forms of
moderately deep water, and, again with excep-
tions, are not well known and are poorly repre-
sented in study collections. It is not unlikely that
the group contains representatives of several evo-
lutionary lines and that at the family level most
of the classifications that have been proposed em-
brace horizontal groupings.

Miiller and Henle (1841) placed all the sharks
known by them to be egg layers in the family
Scyllia, including both the scyliorhinids and the
orectolobids without making a distinction between
sharks in which egg cases are resorbed after for-
mation or are retained in the oviducts until hatch-
ing (ovoviviparous species) and forms that dis-
charge eggs in leathery cases at an early stage in

,->N2

U.S. FISH AND WILDLIFE SERVICE

development ( oviparous species) . It has long been
known that orectolobid species are either oviparous
or ovoviviparous, but according to Bigelow and
Schroeder (19-18, p. 196), the scyliorhinids so far
as known are oviparous. Poll (1951) and Cadenat
(1959) subsequently reported the ovoviviparous
condition in one species of Galeus. Probably more
data will show that additional scyliorhinid species
are ovoviviparous.

Began (1908) separated the scyliorhinids and
orectolobids as families and included Pseudotri-
akis in the Scyliorhinidae. He recognized only
two other genera in the family and included espe-
cially divergent species within the genus Scylwr-
hinus. White (1937), with the intention of
providing a vertical classification that would bet-
ter reflect phylogenetic lines, proposed two new
families, Aetelomycteridae and Halaeluridae, and
retained the family Catulidae ( = Scyliorhinidae) .
All genera of these three families of White except-
ing Prist iurus (= Galeus) were included in
Regan's genus Scyliorhinus.

Bertin (1939) in a review of the classification
of the cartilaginous fishes placed the cat sharks
together with the orectolobids in the family
Scyliorhinidae, but placed PseudotriaJcis and
Pentanchus in monotypic families. Pseudotriakis
has a very long and low first dorsal fin with its
base entirely in advance of the pelvic fins, and this
is the primary morphological feature separating
it from the scyliorhinids which have short-based
dorsal fins (or single dorsal fin) located poste-
riorly, over or behind the pelvics. Pseudotriakis
is represented by two large species, one, Pseudo-
triahis microdon Brito Capello, reported from the
western Atlantic. Both species are larger than
any known cat sharks. Although PseudotriaJcis
is not treated here as a member of the family
Scyliorhinidae, its relegation to another family
may not be warranted. The distinctive arrange-
ment of tooth rows as diagonal bands character-
istic of PseudotriaJcis also occurs to a lesser degree
in Atelomycterus and has some similarities to the
tooth arrangement in Apristurus. Additional
similarities are found between PseudotriaJcis and
the small scyliorhinid shark from the coast of
Chile originally designated Scyllium canescens
Giinther, 1878.

Pentanchus profundicollis Smith and Radcliffe,
1912, was described from a single Philippine speci-

men as a notidanoid shark intermediate between
the Hexanchidae and Chlamydoselachidae but
with five gill openings instead of six or seven char-
acterizing the former. It is so close to the scylio-
rhinids of the genus Apristunis in general appear-
ance and details of gross structure, however, that
except for the presence of only one instead of two
dorsal fins, it would certainly fall within that
genus. Regan (1908) was of the opinion that
Pentanchus belonged in the family Scyliorhinidae
and suspected that the absence of one dorsal fin was
abnormal or accidental. Although additional
specimens are not yet known, the type USNM 70260
is an adult male in fair condition. This specimen,
disregarding the number of dorsal fins as a charac-
teristic, does not fit the description of any known
species of Apristurus. Furthermore, there is no
evidence from external examination or the appear-
ance in radiographs that the absence of a dorsal
fin (absent from the position occupied by the first
dorsal in Apristurus) is in any way a result of
accident or structural abnormality. Short sections
of the vertebral column from the trunk and caudal
portions of the type were missing when I examined
the type specimen but dissections had been care-
fully made somewhat off center and should not
have affected fin-base vestiges had these been pres-
ent. It appears to me that the separation of
Pentanchus and Apristurus (as in Bigelow and
Schroeder, 1948) is justified and that the two
genera are properly to be placed in the family
Scyliorhinidae.

Distribution and Segregation

About 58 species in 14 genera are known in the
family Scyliorhinidae. With the exception of the
Indian Ocean species, Atelomycterus marmoratus
(Bennett), cat sharks appear very rarely in warm
waters and inhabit shore waters only in the higher
latitudes or in comparatively cool-water areas.
The common rough-dog, Scyliarhmus caniculus
(Linnaeus), of Europe, which figures as a labora-
tory animal in much of the physiological and ex-
perimental work on sharks, is an example of a
species entering shallow waters. Cephaloscyllium
uter (Jordan and Gilbert) of the California coast
frequents relatively shallow water. In the west-
ern Atlantic one species is occasionally taken on
the continental shelf north of the Carolinas and
another species is said to frequent the shallow shore
waters in the vicinity of Cape Horn, but from the

REVIEW OF WESTERN ATLANTIC CAT SHARKS

583

Carolinas to Argentina cat sharks are exclusively
inhabitants of the continental slopes. Atlantic
American records of Apristurus are for the most
part from depths of 750 to 1500 meters, and lower
latitude records of other cat sharks in the region
are from depths of 200 to 750 m.

Along Atlantic American coasts, fewer hauls
have been made in depths in excess of 1,000 m. than
in shallower water and trawling has been limited in
areas where rough bottom topography produced
severe gear losses. Deficiencies in the representa-
tive quality of the collections are due chiefly to
these factors.

Ford (1921), writing about Scyliorhinus cani-
cuius at Plymouth, England, noted that there is a
curious alternating seasonal predominance of the
sexes in adults. In the winter the males were
found to be the predominant sex, whereas in the
summer the females were the more numerous.
Differential preferences by the sexes for depth
(and by inference for temperature) were noted by
Springer (1960) in shallow-water carcharhinid
sharks. This may be true also of some of the cat
sharks. The importance of segregation by size as
a means for protecting the young against preda-
tion by members of their own species is less ap-
parent for cat sharks than for the large voracious
earcharhinids, but perhaps is a useful trait. It is
of interest in this connection that Ford (1921)
reports Scyliorhinus stellaris feeding on the
smaller S. ccmi-culus in the Plymouth area.

Nearly all specimens of cat sharks from the
western Atlantic have been taken in trawls. Most
of those collected by exploratory vessels were
caught in shrimp trawls having 1%- or 2-inch
mesh (stretched). Only the smallest sizes, less
than 6 inches, would be able to escape through the
meshes; larger cat sharks, over 24 inches long,
might sometimes evade the nets.

WESTERN ATLANTIC GENERA

The cat sharks known from the western Atlan-
tic fall into five well marked groups correspond-
ing to the five genera recognized here. Differences
of species within genera in the western Atlantic
are not great except between the two species of
Iliihieliiriis reported from Argentina. Of the
five western Atlantic genera, one genus, Apris-
turux, is probably cosmopolitan in waters of suit-
able depth outside of Arctic and Antarctic Re-

gions. Galeus is present both in the North Atlan-
tic and North Pacific Oceans but has not yet been
found in the Southern Hemisphere if recognition
is accorded Whitley's genus Figaro (1934).
Schroederirhfhys is restricted to the Caribbean
and tropical Atlantic. Western Atlantic mem-
bers of the genus Scyliorhinus form a compact in-
frageneric group differing less from one another
than from species found in the eastern Atlantic or
in the western Pacific. Halaehirus, as understood
here, includes species from the Indo-Pacific region
and the Southern Hemisphere.

The area of marine situations suitable to most
of the species of cat sharks is very small in com-
parison to the total ocean area. Apristurus, which
on Atlantic American coasts is found most com-
monly at depths from 750 to 1,500 m. and may
range into deeper water, occurs over a much
greater geographical area than species of other
genera, possibly being present in ocean basins of
moderate depths. Figure 1 showing the extent
and distribution of bottom along the Atlantic
coast of temperate North America at depths be-
tween 100 and 500 fathoms illustrates the rather
narrow bands in some areas to which cat sharks
may be restricted. Along tropical and subtropical
western Atlantic continental slopes, the ranges of
cat sharks other than Apristurus are extremely
narrow bands.

The largest of the western Atlantic species prob-
ably do not ordinarily attain a length as great as
80 cm., and the smaller species (one species of
Scyliorhinus, one Apristwus, the three American
Gafaus, and Schroed-erichthy*) probably do not ex-
ceed 50 cm. Some eastern Atlantic and South
African species are larger. Scyliorhinus stellaris
(Linnaeus) of the eastern Atlantic reaches a
length of 150 cm. in the Atlantic but only about
75 cm. in the Mediterranean (Tortonese, 1956).
Smith (1949) gives maximum sizes of 4 feet (122
cm.) or more for Scyliorhinus capensis (Midler
and Henle) and Conoporoderrna africanwm
(Gmelin) of South African coasts.

At the present time, a revision of the family in-
volving a review of generic or family classifica-
tions using some of the more advanced modern
methods that are available is impractical because
insufficient descriptive data exists for most named
species. Furthermore, it is very likely that a rela-

584

U.S. FISH AND WILDLIFE SERVICE

Figure 1. — More than 95 percent of the specimens of scyliorhinids from the western North Atlantic available for
study have been collected within the 100- to 300-fathom (183- to 914-m.) depth range shown here.

tively large number of unnamed species exist, tin-
described not because their differences from other
species have not been recognized, but undescribed
because examples have not yet been caught. For
this study, more than half the specimens have been
collected within the past five years.

To anticipate in detail the needs of future
studies is presumptuous, but some of the char-
acters of the genera of the cat sharks of the west-
ern Atlantic that have been little used in orthodox
or classical studies seem worth discussion even
though these cannot be fully utilized in reaching

taxonomic decisions in this geographically limited

study.

Color and color pattern

Western Atlantic cat sharks fall in two groups
with respect to color pattern. All Apristurus are
nearly uniform in color, and preserved specimens
are either black or dark brown of various shades
but with no tendency to the formation of any
pattern. A few specimens that I have seen
brought to the surface from hauls in the northern
Gulf of Mexico were uniform black, but these
became either very dark gray or dark brown after

REVIEW OF WESTERN ATLANTIC CAT SHARKS

585

preservation. Areas of skin not covered by den-
ticles, around the gills for example, remained
darker; and edges of fins, where denticles are
sometimes either more numerous or are absent, be-
came a different shade of brown or black than the
rest of the body surfaces after preservation. The
material examined suggests that there is no diag-
nostic significance to brown or black color in mu-
seum specimens because color changes variously
after preservation.

Excepting Apristurus, all Atlantic American
cat sharks now known are somewhat darker above
and lighter below, and furthermore, all have some
pattern of spots, blotches, or lines on the dorsal
surfaces, either lighter or darker than the back-
ground color. This does not pertain outside the
western Atlantic where the genus Galeus. for ex-
ample, is represented by some species without
markings, at least as adults, and other genera,
Parmatwrus for example, are represented by spe-
cies that are uniformly dark.

The two species of western Atlantic Galeus have
color patterns that differ in intensity among the
three forms but show more resemblances to one
another than to color patterns in any other genus.
The patterns in Galeus are complex and difficult
to describe. Because pattern differences in this
genus are obscured by differences in intensity of
pattern, they are of low value in field identification
and other characters are not only more easily
described but also may be more reliable.

Species of the three other genera as represented
in the western Atlantic, ScyliorMnus, Schroeder-
ichthys, and Halael/wrus, have essentially similar
basic color patterns but have diagnostically useful
modifications of the basic patterns. As indicated
by the few species of which juvenile examples are
available, and in its simplest and most persistent
form, the basic pattern consists of a series of seven
dorsal saddles or blotches. Depending upon
species, either more saddles may be present in in-
termediate positions or some of the main saddles
may be obscure.

A parallel development of pattern in Scyli-
orhinus torrei Howell-Rivero and Si-hroederirh-
thys maculatus (one of the new species described
here) illustrates this. Both species have the seven
dorsal saddles appearing in some individuals but
generally more prominent in the young. In
adults of both species, however, the saddles may

become quite indistinct with a partial substitution
of a pattern of small white spots on a tan back-
ground color. The tan color here is the color in
life and is not brought about by preservation.
The saddles seem to become more distinct with
preservation. In life or when freshly preserved
the two species are so similar in appearance of the
color and pattern that the rather great structural
differences may be overlooked easily.

Variation in pattern within species in t he-
material at hand is moderate and reasonably well
defined. Figure 2A shows a rather extreme ex-
ample of the absence of full development of a retic-
ulate pattern characteristic of ScyliorMnus retifer
(Garman), whereas figure 2B shows a specimen
with the reticulate pattern fully, but not uni-
formly, developed. Although this pattern is
variable, it can be distinguished readily from pat-
terns made up of discrete black spots or white
spots.

Reproduction

Most cat sharks lay eggs in cases which, when
first laid, are impervious and sealed against the
entry of seawater. During development of the
embryo, slits appear in corners of the egg cases to
permit a flow of sea water through the egg case.
Tendrils, one from each of the four corners of the
egg case, attach it to objects on the bottom when
the eggs are laid.

In addition to information on the egg laying
habits of Apristurus riveri, available records and
material show that ScyliorMnus retifer and
Schroederichthys maculatus lay eggs. No positive
information is at hand for other western Atlantic
species, but an egg case with developing embryo
(fig. 3) may be presumed to be either Scylior-
Mnus meadi or S. torrei on indirect evidence of
locality.

The genus Galeus is represented in the eastern
Atlantic, including Icelandic waters, by four
species among which are two little-known forms
without markings or color patterns; these were
described from specimens from the Hebrides and
from Iceland. The remaining eastern Atlantic
forms include Galeus melastom/us Rafinesque, an
egg layer, and Galeus poll! Cadenat, an ovovivip-
arous species that retains vgg* in the oviduct until
after the egg shell has been absorbed and after the
embryo has completed absorption of the yolk
saC. No positive evidence has been found to

586

U.S. FISH AND WILDLIFE SERVICE

Figure 2. — ScyHorhimis retifer (Garcnan) : A, Drawn from a 465-mm. female; B, drawn from a 3S0-mm. female.
Both specimens collected in 365-385 m. off Pensacola, Fla. The upper figure shows a specimen with seven major
saddles but with the addition of one intermediate saddle between the two dorsal fins. The darker reticulations
in the lower figure can be seen to delineate seven major saddles.

show whether or not western Atlantic species pro-
duce living young. Probably both western
Atlantic species are ovoviviparous. No shelled
eggs have been found in oviducts of the many
adult female specimens that have been examined,
and no unidentified egg cases small enough to be-
long to Galeus have been seen.

Claspers and clasper siphons

Leigh-Sharpe has proposed that more considera-
tion be given to the structure of the claspers and
clasper siphons or clasper glands in taxonomie
studies of elasmobranchs. In a series of papers
published between 1920 and 1926 he described these

Figure 3. — Egg case of a cat shark collected off Cape Ken-
nedy, Fla.. showing a developing embryo within its en-
tirely transparent and colorless case and showing the
characteristic method of attachment of the case. The
degree of transparency of the egg case, the shape, and
the nature of surface markings on it vary with species.
Transparent egg cases which may be quite free from
color when fresh may become brownish after storage in
alcohol. The embryo color pattern and the site of col-
lection of the egg case suggests that it is SoyliorMnus
tneadi. Drawn from an egg case approximately 1.4 by
4.0 cm. exclusive of tendrils.

REVIEW OF WESTERN ATLANTIC CAT SHARKS

587

Figure 4. — Diagrams showing general shapes of claspers and clasper siphons in adult male eat sharks : A,
Scyliorltinus torrei and B, Galeus arae, both from the Florida Straits; C, Schroederichthys tnacufatus
from the western Caribbean ; and D, Apristurus riveri from the southwestern Caribbean. Each drawn
to scale but scales are unequal.

structures in some scyliorhinids in detail (Leigh-
Sharpe 1920, 1922, 1924, 1926a, and 1926b). In
practical application for taxonomic studies, how-
ever, fhere is some difficulty because of inadequate
series of specimens. Of the 15 western Atlantic
scyliorhinids treated here, for example, adult
male specimens were not available for 6 species.

Diagrams outlining the genera] size and shape
of claspers in relation to the pelvic fins and outlin-
ing roughly the extent of the clasper siphons are
shown in figure 4 for representatives of four west-
ern Atlantic genera. No important differences in
gross examination were noted among adult males
of the two species of western Atlantic Galeus.
Supplementary examination of a few adult male
Galeus from the eastern Atlantic and from the
Pacific failed to reveal substantial differences in
clasper structures within the genus excepting the
presence of hooks on specimens of western

Atlantic' species examined and the absence of these
on the only eastern Atlantic adult male available.
The available material is insufficient to show
whether clasper structures of western Atlantic
scyliorhinids are useful in the diagnosis of species,
but from a necessarily cursory review it appears
that they might be quite useful as generic
characters.

Hooks were present on claspers of the species
of Galeus but were absent on Apristurus and
Schroederichthys and from the claspers of west-
ern Atlantic tScyliorhhius examined. Hooks were
not found on a clasper of one Galeus melastoirms
from the eastern Atlantic.

The denticles on the surfaces of claspers in all of
the specimens examined have their points directed
forward toward the base of the clasper. The re-
versal of direction of the denticles is noted as oc-
curring in Scyliorhinus stellaris (=ScyUium

f,NS

U.S. FISH AND WILDLIFE SERVICE

catulus) by Leigh-Sharpe (1920) and apparently
is a feature common to all galeoid sharks but not to
sharks of other suborders.

Shape of body and fins

The caudal axis in the family Scyliorhinidae is
little elevated and, excepting adults of Scyliorhi-
nus, the overall shape of western Atlantic species
is slender. One genus, Schroederichthys, has a
very elongate postpelvic trunk region.

The length of the body cavity relative to the
overall size of the fish (volume) differs consider-
ably in the four genera found in the tropical and
northern Atlantic. This difference is reflected in
the size of the liver and it appears likely that
with sufficient material for study it would be found
that liver characteristics would be useful as tax-
onomic criteria. The general shape of the liver
is shown in figure 5.

A series of Pacific Apristurus brunneus ex-
amined in comparison with Apristurus riveri from
the Atlantic show some apparently constant dif-
ferences in liver shape. In A. brunneus the liver
is larger and in most specimens the right and left
posterior lobes are united for most of their length,

excepting only that part just anterior to and ex-
tending past the cloaca. In A. brunneus the liver
almost completely covers the visceral cavity when
viewed from the ventral aspect. Only the falci-
form ligament and the rectum are visible in addi-
tion to the liver when the body cavity is opened
vent-rally. Thus it would seem from casual inspec-
tion that large ripe eggs from the ovary located
under the liver when viewed from the ventral as-
pect (only right ovary functional in scyliorhinids)
would have to make a remarkably long or tortuous
journey to reach the opening of the oviducts.

It may be significant in indicating possible deri-
vation of the orectolobids which have quite short
snouts with reduced or absent rostral cartilages,
that western Atlantic ScyUorhinus and Halae-
lurus have relatively short snouts, Schroederich-
thys has a moderately short snout, but both Galeus
and Apristurus are long-snouted. Associated with
the long snouts of Galeus and Apristurus is the
comparatively greater prominence of the external
pores for the Ampullae of Lorenzini. The exten-
sive pore system of the Ampullae of Lorenzini in
Apristurus may be associated with its habitat

Fioure 5. — Diagrams of the arrangement of visceral organs showing liver shai>es (stippled areas) in repre-
sentatives of four western Atlantic genera: A, ScyUorhinus retifer; B, Galeus arac; C, Schroederichthys
maculatus; and D, Apristurus riveri.

REVIEW OF WESTERN ATLANTIC CAT SHARKS 589

793-358 O — «6 5

which is in comparatively deeper water than any
of the other cat sharks. Pineal windows were not
seen in the specimens of Apristurus or any other
cat sharks examined. Among sharks, these are
consistently present in the squaloid genus
Etmopterus, members of which are black.
Dermal denticles

The size, arrangement, and structure of dermal
denticles are often quite useful characters for prac-
tical problems in identification of sharks. Ordi-
narily the typical dermal denticles used in descrip-
tive accounts of species are those from a lateral
surface near the first dorsal fin but below the mid-
dorsal line. Here, unless some specific location
is indicated, denticle descriptions are from den-
ticles taken at a point about halfway along a line
between the axil of the pectoral fin and the origin
of the first dorsal fin. In some instances, differ-
ences in the denticle structure are the most reliable
and definite, means of determining species. For
example, Squalus blainvillei is readily distin-
guished from Squalus cubensis by great differences
in denticle shapes. Among scyliorhinids of the
western Atlantic, denticle differences are either
less well marked or need qualification as to loca-
tion or as to the size or age of the specimens in-
volved in comparisons.

In Scyliorhinus retifer the denticles increase in
size as the shark becomes larger and the denticles
change somewhat in shape. In some sharks it is
evident that the number of denticles increases as
the shark grows large, but in the series of S. retifer
examined, positive evidence of an increase in the
number of denticles with increasing size was not
apparent in a cursory examination. The general
aspect of a section of skin surface with denticles is
shown in figure 6.

In Scyliorhinus retifer denticle shapes on differ-
ent parts of the body vary and the variation fol-

Figure (>. — Dermal denticles from a series of female
Scyliorhinus retifer from the Gulf of Mexico. I/eft
from a specimen 1 T.I mm., center from a 295-mm. speci-
men, and right from a 465-mm. specimen. Camera
lucida drawings to the scale indicated.

lows a pattern more or less characteristic of all
galeoid sharks. On the ventral surfaces the denti-
cles have much less prominent ridges and the lat-
eral points are generally absent. On leading edges
of fins the denticles are usually smoother and flat-
tened so that there are no projecting points. On
the head and especially those parts of the head
used sometimes for bumping objects, the denticles
are somewhat shorter with thicker edges or points.

Denticles of Gal-ens and Apristurus follow this
plan to a less marked degree. The denticles of
ventral surfaces are about the same shape as those
of the dorsal surfaces, but their construction is
lighter.

Specialized dermal denticles forming a crest
along the upper margin of the caudal fin are found
on all species of the genus Galeus, varying slightly
among species but probably not sufficiently to be
used in practical field identification. The genus
Figaro Whitley has been described from Austra-
lian waters and differs in having the specialized
scales on both the upper and lower margins of the
caudal fin. The eastern Pacific genus Parniaturus,
quite unlike Galeus in many respects, has a denticle
crest on the upper caudal fin margin.

Although not having a definite crest, Apristurus
profumdorwm has several rows of compactly ar-
ranged, imbricate denticles along the upper mar-
gin of the caudal fin. The body and sides of the
fins in that species are quite sparsely clothed with
denticles which are nearly erect.

The young of Scyliorhinus canicuhis and S.
stellaris have a series of enlarged scales, one series
on each side of the middorsal line extending from
the shoulder area back to the first dorsal fin. Ac-
cording to Ford (1921), these scales are visible in
embryos of S. caniculus taken at Plymouth, Eng-
land, when the embryos are 44 mm. long. They
persist for a short time after hatching, but similar
scales are present on S. stellaris and may still re-
main in place until the sharks are over a foot long.

Enlarged scales are present on an embryo (fig.
8) presumed to be S. retifer. They are not visible
in specimens of 150 mm. or more, but on specimens
of newly hatched S. retifer they are represented
sometimes by a series of scars. Enlarged denticles
in a similar position but widely spaced are present
in Halaebwrus from Chile, usually surrounded by
a ring of somewhat modified smaller denticles.
Series of enlarged denticles are present on both

590

U.S. FISH AND WILDLIFE SERVICE

■ kr-'

r ■ ••-"

I 1 mm.

"*~"

C L.

Figube 7. — Camera lueida drawings of denticles from some western Atlantic catsharks : A, Scyliorhinus
meadi from 264-mm. immature male; B, Apristurus prof undo rum from 380-mm. immature female; C,
Scyliorhinus torrei from 243-mm. adult male; D, Scyliorhinus hesperius from 296-mm. immature male;
B, Apristurus riveri from 450-mm. adult female ;• F, Schroederichthys maculatus n. sp., from 295-mm. adult
female ; G, Scyliorhinus retifer from 410-mm. adult male ; H, Galcus arae from 287-mm. immature
female. Note : Denticles of Apristurus profundorum are more erect over most of the body surfaces than
shown here, their points projecting almost perpendicularly from the plane of the skin surface.

sides of the middorsal line of a 160-mm. specimen
of CephaloscyUiwrn uter from Monterey Bay,
Calif.

Teeth

The teeth of scyliorhinid sharks are small, most
commonly with a larger central cusp having one
or more smaller lateral cusps on each side. In some
species of Apristurus the teeth nearer the corners
of the mouth may have many cusps (as many as
nine have been noted) with the central cusp but
little higher than adjacent ones. In Atelo-
nvycterus from the Indo-Pacific, the cusps of some
of the teeth near the corners of the mouth are
much reduced and the rows are fitted so close to-

gether as to form an almost smooth grinding sur-
face.

Except for specimens of Apristurus, the tooth
form does not vary greatly in the scyliorhinid
specimens examined from the western Atlantic
and it is probably impractical to attempt to dis-
tinguish most species from teeth alone. Western
Atlantic Apristurus, as a general rule, have teeth
with more cusps and, in some Apristurus, crowd-
ing of some of the lateral cusps in front of the
central cusp (see fig. 9D) is frequent.

In Apristurus riveri the most extreme tooth
dimorphism yet reported for sharks occurs. The
two adult males that constitute our entire series of

REVIEW OF WESTERN ATLANTIC CAT SHARKS

591

Figure 8. — Egg case of a cat shark collected from 100
fathoms off the coast of North Carolina, showing an em-
bryo with the two series of enlarged denticles that
characterize the young in some species of scyliorhinid
sharks. Presumably this is an embryo of Scyliorhinus
retifer. The somewhat opaque white banding in the
shell has not been reported previously and may not
always be evident in egg cases of the species.

males of that species not only have teeth twice
as long as the teeth of females of comparable size
but the teeth of the males are also quite different
in shape from those of the females, with lateral
cusps entirely absent on the teeth of the central
part of the jaws. A few teeth with lateral den-
ticles or cusps are present among the last few rows
toward the angles of the jaws.

This degree of dimorphism illustrated by the ac-
companying diagram (fig. 10) does not occur in
the other species of Apristurus that are represent-
ed by sufficient material to check. The teeth of
males of the Pacific species, Apristurus brunneus,
are somewhat larger than the teeth of females of
comparable size, but there is no important differ-
ence in tooth shape, No significant dimorphism
is present in A. pr&fundorum, A. indicus, or A.
laurussoni.

It is suggested that (he modification in teeth
would function effectively to hold the female, per-
haps by the pectoral fin, during copulation.

With reference to Halaehirus from Patagonia,
Yaillaiu (1891) states that: one finds greal vari-

1 mm

Figure 9. — Camera lucida outlines of teeth from upi>er and
lower jaws, shark's right side, fifth lateral row count-
ing from the symphysis: A, Soyliorhinus hespervus, a
272-mm. female ; B, Galcus arac. a 365-mm. male ; C,
Schroederichthus maculatus, a 220-mm. male; and D,
Apristurus indicus, a 430-mm. female.

ation in the teeth of the lower jaw with differences
following size and perhaps sex. Also in a table
of differences between Scyllium biviu/m and S.
chMense {ScyMium= Halaehirus), Vaillant notes
that the lower jaw teeth of biviiim are not very
small and are either without lateral cusps or with
lateral cusps not very distinct, whereas the teeth
of the lower jaw in chilense are very small and
have no lateral points. In spite of complications
of nomenclature and contradictions in the litera-
ture, it is obvious that South American Halaehirus
exhibit a transition in tooth form. A more
thorough study is necessary to determine whether

592

U.S. FISH AND WILDLIFE SERVICE

|CO

5 mm

I CO

IU5

Figure 10. — Camera lucida outlines of teeth of 405-mm.
adult female Apristurus riveri (left) compared with
same scale outlines of teeth of 430-mm. adult male

( right) both specimens from 860- to 914-ni. depth off the
Caribbean coast of Panama.

changes in tooth form occur at sexual maturity or
whether several species with different tooth forms
are involved with or without changes during
growth. South American HaZaelurus (not in-
cluding the deeper water form ScyUhim eanescens
Giinther) shows a trend toward development of
spike dentition in the lower jaw. Spike teeth in
the lower jaw and cutting teeth in the upper jaw
always characterize species of the larger and more
specialized galeoids wherever differences in ap-
parent function between upper and lower jaws
exist. In contrast, in the notidanoids and squal-
oids it is the upper jaw that has spike teeth.

It has been customary to express a tooth for-
mula for extant sharks simply as the number of
teetli in the upper jaw over the number of teeth
in the lower jaw. In sharks having only one
functional band of teeth, the counts are rather
easily determined. In C ' archarhinm leucos, for
example, this would be 27/25 where 27 is the num-

ber of teeth on the upper jaw and 25 is the number
on the lower jaw. A refinement of this kind of
formula, used for example by Bigelow and
Schroeder (1948), breaks down the count to indi-
cate the number of very small teeth at or near the
jaw symphyses. In C. leucas such a count might
be expressed as 13 + 1 + 13/12 + 1 + 12, where 13
is the number of teeth on each side of the upper
jaw, 12 the number on each side of the lower jaw
and 1 represents the number of very small teeth at
the symphysis. Leriche (1905) developed a clas-
sification of the various types of teeth found in
the jaws of fossil sharks which permits the use of
a more descriptive and meaningful formula to ex-
press conditions found in various species. Apple-
gate (1965) has proposed some modification of the
Leriche system and an extension of its use to ex-
tant species. This system has obvious merits al-
though its formulas are perhaps less informative
about scyliorhinids than about, species in most

REVIEW OF WESTERN ATLANTIC CAT SHARKS

593

other shark families. No attempt has been made
to use it here because of this and because only
about half the scyliorhinid genera are being
reviewed.

Strasburg (1963), in discussing tooth replace-
ment in a squaloid species, fsistius, used the terms
independent dentition, alternate overlap, imbricate
overlap, and mixed alternate and imbricate over-
lap to describe the arrangement of teeth in a trans-
verse band and to distinguish these arrangements
from the modified imbricate overlap found in
Isistms. He found no pure alternate dentition in
the species he examined, but these did not include
a scyliorhinid.

In scyliorhinids several transverse series of
teeth are functional. For the purposes of this dis-
cussion a series of teeth is defined as a file or array
of teeth along a single line running parallel to the
jaw cartilage axis from one corner of the jaw
opening to the other. A row of teeth on the other
hand is defined as a file of teeth in a line extending
from a germinal area on the inner surface of the
jaw to the outer rim of the jaw or lip. Rows of
teeth are frequently, but not always, arranged in
a line on a plane perpendicular to the axis of the
jaw cartilage.

In all scyliorhinid sharks several series of teeth
are functional, and in addition two or more series
of developing teeth are present along the inner
side of the jaw. The developing teeth are covered
there by the lining of the mouth which forms a
protected space, in which tooth buds form. In
Scyliorhinus, Galeus, and Schroederichthys four
or five functional series are usually present in each
jaw and in Apr'tsturus five or six functional series.
Impressions or scars of tooth bases are often vis-
ible at the outer ends of tooth rows. If two series
are considered together as one band, the arrange-
ment is alternate, the teeth in the outer series being
present in half the tooth rows with their bases
overlapping the alternately occurring teeth of the
next functional series. The teeth of all specimens
of scyliorhinids examined were somewhat crowded
with a considerable degree of overlap (see fig. 11).
Alternate dentition with less crowding is to be
found in some sharks of other groups. The ar-
rangement of teeth which, following Strasburg
i L963), would probably be called modified alter-
nate dentition if found in Pristiophorusi but with
less crowding has a quite different appearance from

the typical arrangements in scyliorhinids. In
Prist to pharus (fig. 12) the number of rows of teeth
are readily counted, and no confusion results from
the appearance of diagonal files of teeth.

Figure 11. — Head of a 430-mni. adult male Apristurus
riveri showing diagonal files of teeth in the lower jaw
at the left side of the photograph. Dentition in this
specimen is alternate throughout. Reflections from
base of some of the teeth appear in the photograph to
depict accessory cusps, but in reality none are present
on teeth that are shown in the photograph.

The presence or absence of a separation of the
teeth of one side of a jaw from teeth of the other
side by a band of fleshy material seems to be a
variable in the scyliorhinid specimens examined.
Many specimens of Apristurus have such a sepa-
ration either in the upper or lower jaw or both,
whereas some do not. Furthermore this vari-
ation occurs in series of the same species. The
extent to which this variation may be the result of
stretching of ligaments at the symphysis has not
been determined.

The number of tooth rows in some scyliorhinids
is difficult to count for a variety of reasons. The
teeth are small, and toward the angles of the jaws
low-crowned multicusped teeth are not clearly de-
fined. The teeth are crowded, and in a few speci-
mens, or perhaps a few species, the arrangement of
the teeth is not a simple alternate arrangement but
is mixed. Similarities between the cat sharks,

594

U.S. FISH AND WILDLIFE SERVICE

Figure 12. — Teeth of the saw shark, Pristiopho-rus
schroederi (Pristiophoroidea), showing a modified al-
ternate tooth arrangement differing from the arrange-
ment found in the Scyliorhinidae (Galeoidea) chiefly
in the lesser degree of crowding. Photograph by Los
Angeles County Museum.

Scyliorhinidae, and the false cat sharks, Pseudo-
triakidae, already have been noted. The upper
and lower jaw teeth of Pseudotriakis microdon
Bocage and Capello are illustrated in Bigelow and
Schroeder (1948) and are described and discussed
in more detail by Jaquet (1905). The arrange-
ment of teeth in the lower jaw in Pseudotriakis
and Apristurus have some similarity in ap-
pearance due to the rather well defined diagonal
files of teeth. Gross examination of the type spec-
imen of Pseudotriakis acrages Jordan and
Snyder (SU 12903) shows the diagonal files of
lower jaw teeth continuing widely separated, but
with the teeth within a file quite close together,
back to the germinal area (see fig. 13). This ap-
pears to indicate a diagonal movement of the teeth
from the area of budding into the functional posi-
tion, but such an explanation is superficial. A
study of the comparative histology of the develop-
ing teeth in several families of sharks should prove
helpful in indicating relationships.

NUMBER OF VERTEBRAE

Vertebrae were counted from radiographs of
specimens of the family, but the diplospondylous
vertebrae near the tail tips were difficult to count.

Figure 13. — Upper photograph showing diagonal files
of teeth in the lower jaw of the type specimen of
Pseudotriakis acrages Jordan and Snyder (SU
12903). Lower photograph, same jaw rolled out-
ward with the tooth germinal area exposed and
showing .continuation of the files diagonally on the
dental lamina where they become progressively
smaller and softer to the point of their apparent
origin.

Furthermore, in some radiographs it was not pos-
sible to determine whether all of the terminal ver-
tebrae appeared. Since it was always possible to

REVIEW OF WESTERN ATLANTIC CAT SHARKS

595

count the number of monospondylous vertebrae
with confidence, only these counts are given here
(table 1).

The series reported here is too small for defini-
tive use, but is sufficient to give promise that a
more comprehensive study would be helpful in
species diagnosis. Several kinds of interpretive
factors may require consideration in a more com-
prehensive study. Some variation in meristic
characters would not be surprising in a sample col-
lected over a large geographical range. In our
series of 33 counts from Apristv/rus indicus, the
counts vary from 35 to 41, and localities of capture
range over 20 degrees in latitude. In the series of
25 counts for Aprixtvrux Imiruxxoni a single count,
higher than the cluster, is the count for the holo-
type, taken about 20 degrees north of any of the
other specimens of the series.

The reliability of counts of vertebrae for pur-
poses of numerical analysis or for identification is
reduced because of abnormalities occasionally
present. In the distribution of counts in 34 speci-
mens of Schroederiohthys maculatus, for example,
where 33 are clustered but one count is somewhat
apart, the high count in this specimen appears to
be attributable to an uneven transition to diplo-
spondyly. Here a few displospondylous verte-
brae, appeared well forward in the trunk region.

MORPHOMETRICS

The conventional ways to measure sharks are
comprehensively illustrated by Garrick and
Schultz (1963, figs. 1A and IB), and this system
of measurement is used here insofar as possible.
Unfortunately measurements very useful for some
sharks are difficult to apply to others. In the
scyliorhinids, for example, the axis of the caudal

fin is not perceptibly elevated and the point at
which the upper lobe of the caudal fin begins is
merely an estimate. The fins of scyliorhinid
sharks, especially Apristurus, are soft and are gen-
erally rounded or lobelike structures making fin
measurements difficult to define.

Most diagnostic accounts of scyliorhinids rely
greatly upon morphometries as key characters to
separate species or genera. These characters are
at least accessible and their use does not require
a microscope. As applied to scyliorhinids, how-
ever, some kinds of comparative measurements
seem to be particularly unreliable.

In comparing fin sizes, for example, the state-
ment that the length of the base of the anal is 4
times the length of the base of the first dorsal fin
in one species, but only 2i/> times the length in an-
other species, introduces a variety of difficulties in
practical application. Precise measurements of
the length of fin bases are not easily made because
of the gradual slope of the forward end of the fin.
This is sometimes complicated by the distortion or
shriveling of the specimen in preservation. The
lengths of fin bases may vary independently.
Thus a comparison that seems quite clearly to dif-
ferentiate species when some specimens are com-
pared may be quite inadequate for other
specimens.

In scyliorhinids there are occasionally speci-
mens having much longer gill slits on one side than
on the other, and gill slits are especially subject to '
distortion in length or even in position by
preservation.

The ease with which data on measurement can
be communicated and the difficulty of correctly
and adequately describing shape seem to have led
to overemphasis of measurements and less than

Table 1. — Frequency of occurrence of various numbers c

/ monospondyl

OUS

vertebrae in some

western Atlantic cat st

arks

Number of monospondylous vertebrae

39
2

5
4

41
8

7
1

1
....

3
3

2
2
1

"i"

4
1

1
12
7

14
1
4

1
1

4
3

13
2

8
8

1
4

596

U.S. FISH AND WILDLIFE SERVICE

desirable treatment of other characters. Measure-
ments remain useful in description, but some bet-
ter balance and the use of a large number of char-
acters, including some that can best be described in
illustrations, seems desirable and perhaps neces-
sary for a revision of the family.

KEY TO GENERA OF WESTERN ATLANTIC
SCYLIORHINIDAE

The following key to western Atlantic genera
is sufficient for their separation, but the degree of
difference between them is better illustrated in
the chart given as table 2.

KEY TO WESTERN ATLANTIC GENERA OF
SCYLIORHINIDAE

1A. Color uniform lilaek or dark brown except for lighter

or darker fins in some species Apristnrus

IB. Color variegated with spots, blotches or saddles.

lighter below 2A or 2B

2A. Crest of enlarged denticles along upper edge of caudal

fin Galeus

2B. No crest of enlarged denticles along upper edge of

caudal fin 3A or 3B

3A. Tip of snout to anus about one-third of total

length Schroederichthys

3B. Tip of snout to anus about three-eighths to one-half

of total length 4A or 4B

4A. Labial fold present only along lower jaw

Scyliorhinus
4B. Labial fold around corner of mouth extending along

both jaws Halaelurus

Genus Scyliorhinus Blainville 1816
Type species — Squalus canicula Lac£pede, designated
by Gill, 1861.

Western Atlantic species of /Scyliorhinus differ
from one another primarily in color pattern al-
though one species, Scyliorhinus torrei, is much
smaller than the other four and another, S. meadi,
has more erect and slightly larger denticles than
any of the others, giving it a somewhat shaggy
appearance.

Scyliorhinus t&razame (Tanaka) [ = Halaelurus
nulls (Pietchmann)] of Japanese waters, S. stel-
lar Is (Linnaeus) and S. canicula (Linnaeus) of
eastern North Atlantic waters, and S. capensls
(Miiller and Henle) of South Africa and the east-
ern Indian Ocean, all differ in details of color pat-
tern from one another and from American species.
No eastern Pacific species are known. Specimens
of S. torazams that have been examined have the
pelvic fins united to a point somewhat nearer their
tips than most specimens of the American species
and have enlarged and nearly erect dorsal denticles
rather regularly scattered on dorsal surfaces
among more numerous smaller ones ; but the larger
denticles are not arranged in rows, and the charac-
ter seems to be variable. The American species,
excepting S. torreL have slightly longer snouts
than other species. The European S. canicula has
the two nasal flaps united at the midline, and the
confluent flap reaches the edge of the upper lip.
As for other members of the genus, nasal flaps are
often smaller in examples of the American species
than in others, but specimens can be selected from
series of S. stellaris and S. retifer, for example, in

Table 2. — Characteristics of genera of the family Scyliorhinidae as present in western Atlantic species

Characters

Scyliorhinus

Halaelurus (shortest
snout)

Galeus

SchToederichthys

Apristurus (longest
snout)

Color.

Caudal crest.

Labial grooves

Union of pelvic fins
posterior to anus.

Enlarged dorsal
denticles.

Claspers

Clasper siphons.
Egg retention

Sexual dimorphism in
tooth shape.

Pores on snout

Liver size in adults

Variegated; dorsal sad-
dles present but
sometimes obscure.

None

Weak; present only on

lower jaw.
About two-thirds

united.
Present in embryos;

and scars in very

young.
Short; hooks weak or

absent.

Moderately short.

Oviparous as far as

known.
Not found

Not prominent

Large; posterior tips
usually reach as far
back as anal opening.

As in Scyliorhinus.

Strong on both jaws...

Basal one-fourth to
one-half united.

A few remain in some
adults.

Not examined

Oviparous as far as

known.
Said to be present to

slight degree.

Not prominent.
Not examined...

Plain color or variegated
but without well-
marked saddles.

Present

Moderate on both jaws..

Basal one-half to two-
thirds united.

Few scars on very
young.

Long; hooks present

Moderately long

Both oviparous and

ovoviviparous species.
Not found

Prominent

Moderate; posterior tips
of liver lobes not
reaching as far back
as anus.

As in ScyliOThinus.

None.

Moderate on both jaws.
No union

Not found on material
available.

Long; no hooks

Long

Oviparous as far as

known (in 1 species).
Not found

Not prominent

Short; small; not ex-
tending appreciably
into posterior half of
body cavity.

Black or sometimes
brown; color uniform
without strong mark-
ings.

Absent except partly
developed in one
species.

Strong on both jaws.

Only trace of union.
Not found.

Short; no hooks.

Short.

Oviparous as far as
known (in 2 species).

Strong tooth dimorph-
ism in 1 species, not
in 3 others.

Very prominent.

Large; very long; tips
reaching posterior to
anus.

REVIEW OF WESTERN ATLANTIC CAT SHARKS

597

which there are no appreciable differences in the
shape of the nasal flap or its nearness to the mouth.
Thus throughout the genus Scyliorhinus, except-
ing only S. canicula where the nasal flaps do pro-
vide a structural feature differing from that found
in all other species, the best and by far the most
reliable character for identification of specimens
is their color pattern. Differences in proportions
do exist, and there are other differences in denticle
and tooth structure and in the shape, and position
of fins; but these differences seem to be of little
practical usefulness at this stage of the study of the
family except in the analysis of series of specimens
and in preliminary determinations of probable
relationships.

KEY TO WESTERN ATLANTIC SCYLIORHINUS

Note. — Preservatives dissolve nil from shark livers,
adding yellowish pigments to specimens, sometimes turn-
ing gray colored specimens to brown.

la. Dorsal surfaces (except fins) with randomly arranged
but almost uniformly spaced, light-colored and
nearly round spots in a brown background (browD
in life as well as in preservative) ; darker areas
representing seven saddles may be present but are
usually obscure ; lighter below, without spots.

x. torrei; Florida Straits, off northern coast of
Cuba,
lb. Dorsal surfaces neither brown in life ( but may be
brown in preservative) nor covered by randomly
arranged white spots ; all species with variations on
a basic pattern of seven saddles, a prepeetoral, a
pectoral, postpectoral, first dorsal, second dorsal,
precaudal, and caudal saddles ; additional darker
areas (blotches or saddles) may occasionally ap-
pear in intermediate positions such as between the
dorsal fins, but such blotches or saddles are
usually more obscure than the seven principal sad-
.dies; lateral pattern, when present, sometimes with
a series of blotches roughly alternating with
saddles.
2a. Saddles made up of simple blotches of darker color,
usually without included darker lines or darker
spots ; lighter areas within saddles sometimes
present but rather indistinct, not api>earing as
round whitish spots smaller than diameter of eye;
intermediate saddles and spots outside basic pat-
tern few or absent.

8. meadi new species; Florida Straits. St. Au-
gustine to Santaren Channel.
2b. Saddles and lateral blotches with nearly round, while
or light-colored spots included within their mar-
gins, these spots usually smaller than diameter of
eye; no dark lines or dark spots within the sad-
dles; some specimens with reduced number of

middles.

S. hespcrius new species; western Caribbean, off
Honduras, Nicaragua, and Jamaica.
2c. Dorsal saddles with black marginal lines enclosing
areas of the lighter background color, the enclosed
areas usually not round, in most specimens the
lines forming a reticulate pattern ; the reticulate
pattern commonly extended to form intermediate
patterns obscuring basic pattern of saddles, but
in a few specimens reduced and showing only as
saddles with marginal lines but without reticulat-
ing lines (fig. 2A and 2B show patterns near ex-
tremes of variation in material examined) ; no
round white spots and isolated black spots few.
8. rctifrr (Garman) ; southwestern edge of
Georges Bank (New England) along the outer
continental shelf and the continental slope to the
Carolinas and along the continental slope south-
ward ; off both east and west coasts of Florida ;
along the continental slope in the Gulf of Mexico
and the western side of the Yucatan Channel ;
present on western Caribbean Banks including
Pedro Bank as far south as Latitude 13°30' N.
Not yet reported from Cuba or the Antillean
side of the Straits of Florida.
2d. Pattern of saddles usually outlined by small rounded
black spots which may lw> present also outside the
pattern ; in some specimens black spots are so nu-
merous as to obscure saddles ; no white spots.
S. boa (Goode and Bean) ; Lesser Antilles and
continental slopes of South America from Vene-
zuela to northern Argentina.

Scyliorhinus torrei Howell-Rivero, 1936

Figures 4, 7, 14, and 27 ; tables 1, 3, and 4.

Scyliorhinus torrei Howell-Rivero, Proc. Boston Soc.
Natur. Hist. 41(4) : 43-44, pi. 9, 1936 (type locality
off Havana in deep water).

S. torrei is the smallest species of the genus, the
males becoming mature at about 250 mm. In this
connection it should be noted that Ford (1921)
finds no marked difference in sizes attained by
males and females in Scyliorhinm canicula. and
that the series of all scyliorhinids examined in this
study show no indication that there is a disparity
in size attained by the sexes. The numbers of
adult specimens examined, however, are too few to
show this conclusively for any western Atlantic,
species. The largest specimen of S. torrei recorded
is 209 mm. (Bigelow and Schroeder 1948). As
might be expected from its small size and slender
form, S. torrei has a short liver occupying only a
part of the anterior half of the body cavity. Pro-
portionally large ovarian eggs (in the right ovary
in adult females) with diameters up to 10 mm.
crowd other organs. In gross appearance the
nidamental eland and oviducts in S. torrei are

598

U.S. FISH AND WILDLIFE SERVICE

much the same as in other western Atlantic
scyliorhinids, but it is not known whether S. torrei
is oviparous or ovoviviparous.

Howell-Rivero (1936) in describing S. torrei
noted the presence of a nictitating membrane and
by this (among other characters) distinguished it
from S. torazame of Japanese waters. Among
specimens of both species examined for this study
there is some difference in the degree of develop-
ment, of the subocular fold. Gilbert and Oren
(1964) have called attention to inconsistencies in
use of the terms subocular fold and nictitating
membrane or nictitans, and I follow their rec-
ommendation in restricting the meaning of sub-
ocular fold to indicate a poorly developed lower
eyelid. The presence of a nictitans or its state of
development has sometimes been assumed from the
presence of a subocular fold or its length relative
to the length of the eye. Although there are dif-
ferences in the extent of development of the
subocular fold in different species, there is also
much variation within species apparent in museum
specimens, some of it due to differences in methods
of preservation. Winking by the nictitans was
observed in the two European Scyliorhinus Gil-
bert. (1963), but its functional movement has not
been observed and reported for other scyliorhinids.

In males the extent of union of pelvic fins along
their inner edges is variable in the material ex-
amined. In one immature male the inner edges are
united throughout, and one adult male has tins that
are not united at all. Other males examined have
fins united along two-thirds to three-fourths of
their inner margins. Bigelow and Schroeder
(1948) state that male S. torrei have claspers ex-
tending far beyond the tips of the pelvics. The
illustration (1948, fig. 35), however, shows that
the claspers of their largest specimen reach only a
short distance beyond the pelvic tips. In the mate-
rial at hand, the fully calcified claspers of one
adult male (the largest) fail to reach the tips of
the pelvics. In two others the claspers extend a
very short distance beyond the tips of the pelvics.
The ventral (outer) surfaces of the claspers, in
the unflexed condition, are covered with denticles
except for the extreme tip. Denticle points are
directed anteriorly (toward the clasper base) as in
other sharks of the suborder Galeoidea. The
inner surface does not have either denticles or
hooks in the position indicated by Schmidt (1930)
for hooks on claspers of Scyliorhiniis torazame
(Tanaka). On the adult male S. torrei at hand,
there are somewhat irregular series of slightly en-
larged denticles having sharp points directed ante-

Figure 14. — A, Scyliorhinus torrei Howell-Rivero. drawn from a 258-mm. adult female collected at M/V
Silver Bay station 2457; B, Scyliorhinus meadi new species, drawn from a 190-mm. young male taken
at M/V Combat station 51.

REVIEW OF WESTERN ATLANTIC CAT SHARKS

599

riorly (toward the base of the clasper), but these
denticles are on the side of the rhipidion adjacent
to the main axis of the. shark and in quite a dif-
ferent poistion than the hooks of the claspers of S.
torazame.

The claspers of S. torn i are quite small and
simple structures as compared with the claspers of
Galeus area. The claspers of an adult male
Galeus arae 275 mm. long are obviously more than
10 times the weight or volume of the claspers of
an adult male Scyliorhinus torrei 272 mm. long
and are considerably more complicated.

The stomach on one .6'. torrei contained cepha-
lopod remains (beaks) including a cartilaginous
eye capsule {Sepia?) 12 mm. in minimum diam-
eter. Also present, were several fish scales 4 to
7 mm. in breadth.

In addition to specimens for which measure-
ments are summarized in table 4 (M/V Silver Bay
stations 2457 and 3474 in Santaren Channel),
specimens have been seen from M/V Silver Bay
stations 2475 and 2477 in Santaren Channel; from
M/V Oregon stations 1340 and 1343, also in the
Santaren Channel; from M/V Oregon stations
2482, 3474, and 3512, northward from the San-
taren Channel to the offing of Jupiter, Florida;
and from M/V Orego-n station 2650, near the
Virgin Islands. Previously recorded specimens
were, from the north coast of Cuba (Bigelow and
Schroeder. 1948). All recorded captures were
from 366 to 550 m. except the one near the Virgin
Islands which was in 229 m.

The teeth in the specimens at hand are in 21 +
21/20 + 2 + 20 to 23 + 23/21 + 1 + 21 rows. The
tooth shape is similar to that of other Atlantic
species of Scyliorhinus. In the specimens ex-
amined, the cusps of the extreme lateral teeth of
the lower jaw are variably reduced, in some al-
most absent.

Scyliorhinus meadi new species

Figures a, 7. 14. and 27 ; tables 1, 3, and 4.

Holotype.—An immature male. CSXM 188049, 247 mm.

in total length, taken at M V Silver Ray station 3711.

la I. 2K°21' X.. long. 78°51' W., at 329-m. depth off

Cape Kennedy, Flu.. January 26, 1962.
Vdditional material examint </. The species is known
only from the liolotype, an immature male and two im-
mature females from the same station as the liolotype.
an immature male from M V Silver />'»;/ station '_'17.~i
from r>4!)-m. depth in Santaren Channel, and an immature
male from M/V Combat station 51, off St. Augustine, Fla.
in 329-m. depth.

Diagnosis. — S. meadi differs from other species
of the genus Scyliorhinus in color pattern. The
upper parts are light gray in fresh specimens
(brownish in specimens preserved in alcohol)
with seven quite distinct darker rectangular
blotches or saddles extending across the middorsal
area, the first anterior to the pectorals, the second
and largest (in specimens of the type series) at the
level of the pectoral tips, the third anterior to the
pelvic origin, the fourth through the first dorsal
fin, the fifth through the second dorsal fin, the
sixth at the base of the caudal fin, and the seventh
across the caudal fin, anterior to the notch. In
additional to the dorsal saddles, a series of lateral
blotches of color alternate in more or less checker-
board fashion with the first three or four dorsal
saddles, some of these extending indistinctly to the
upper surfaces of the pectoral and pelvic fins.
Traces of additional dorsal blotdies are present
between some of the principal dorsal saddles in
some of the specimens. Lighter colored areas are
included in some of the blotches, but these are
indistinct and larger than the eye.

Two species of Scyliorhinus, torrei and retifer,
are present in the same geographical area as
meadi, but the color patterns of these are so strik-
ingly different from that of meadi that there
should not be any possibility for confusing them.
No intergrades have been observed.

S. meadi appears to be closest in appearance to
S. hesperius which is described in the following'
pages. Differences in color pattern between the
two are constant in the material examined.

S. meadi also differs from other American
members of Scyliorhinus in having the typical
dermal denticles of dorsolateral surfaces some-
what larger in comparison with specimens of
equal size, somewhat more erect, somewhat nar-
rower, and somewhat more widely spaced. These
differences are all a matter of degree and are not
necessarily apparent unless specimens of similar
size are compared. The differences do, in com-
bination, give S. meadi a more shajr.oy appearance
than any of the other American representatives
of the genus.

Description of liolotype. — An immature male,
247 nun. in total length and having dimensions as
given in table 3. Body robust, caudal axis little
elevated; head broad; snout broadly rounded.
short ; nasal flaps rather large, separated from one

600

U.S. FISH AND WILDLIFE SERVICE

another in the midline, nearly reaching month, no
groove connecting nasal apertures with mouth;
mouth broad, strongly arched; well-developed
labial folds along the inner sides of the jaws ex-
tending about one-fourth the distance toward the
symphysis, no labial folds along outer margins of
jaws; orbital opening elongate, slitlike, a well-de-
veloped fold below the eye, not touching eyeball;
spiracle small, its diameter less than one-fifth
length of eye, located slightly below level of eye
and at a distance about one-third the eye's lon-
gitudinal diameter from corner of eye ; third gill
slit above origin of pectoral, fourth, and fifth gill
slits over pectoral; first dorsal fin slightly larger
than second, its origin over the posterior half of
base of pel vies and slightly nearer tip of snout
than tip of caudal fin; pelvic fins united along
their inner margins for about half the distance
from cloaca to fin tips ; pectorals broad, their free
corners rounded, distal margins nearly straight.

Bases of typical denticles of dorsolateral sur-
faces separated from one another by distances one
to four times the diameter of their bases; denticles
three pointed, the central point long and heavy,
lateral points weak and quite small with a strong
central ridge, most denticles nearly erect, much
longer than wide, their points directed upward
and posteriorly; belly denticles similar; a few
denticles of the edges of fins flattened, leaf-like,
and without lateral points.

Teeth similar in the upper and lower jaws, three-
cusped with an additional pair of lateral denticles
on some teeth: the central cusp of teeth of the
midportion of the upper jaw about twice as high
as lateral cusps; teeth toward the angles of both
jaws and in the lower jaw with somewhat lower
central cusps; about three series of teeth func-
tional, in about 25 + 0 + 25/25 + 0 + 25 rows.

Color pattern as described in preceding key
and diagnosis.

Notes. — 8. mendi specimens were collected with-
in the general geographical range of S. retifer and
adjacent to the areas in which 8. torrei have been
found. It is possible that all three species occupy
different habitats. Species of Scyliorhinus taken
by exploratory fishing vessels off the southeastern
States and in the Caribbean have been, with one
exception, collected from depths between 180 and
914 m. Along much of the Atlantic coast this is
a relatively narrow strip (fig. 1). In the Florida

Straits region, a wider band of sea-bottom falls
within this depth range and supports a remark-
ably diverse fauna of sharks and rays. Collections
in the area in general suggest that many of these
have quite restricted distributions, possibly due
to narrow habitat preferences.

S. meadi is named for Giles W. Mead, who first
called my attention to a specimen of the species.

Scyliorhinus boa Goode and Bean, 18%

Figures 15 and 27 ; tables 1, 3, and 4

Scylliorhinus boa Goode and Bean, Spec. Bull. U.S. Nat.

Mus., p. 17, 1S96 (type locality, Blake station 291, off

Barbados).
Catalus haeckelii Miranda-Ribeiro. Mem. Mus. Nac. Rio

de Janeiro, 14 :163, pi. 8, 1907.
Scyliorhinus fernandezi Weibezahn, Novedades Cient.

Mus. Hist. Nat. La Salle, Caracas, Ser. Zool. No. 9:

3-7, 1953.

Goode and Bean (1896, p. 17) did not intend to
describe the species but did, in fact, satisfy the re-
quirements of a valid description by publishing a
name and a diagnosis based on the single 6-inch
specimen collected off Barbados which is the type
(Harv. Mus. Comp. Zool., 1335). They note a
general correspondence in color with 8. retifer
and state that in approximately the track of the
narrow lines observable in Garman's specimen (S.
retifer) may be found various spots and blotches
of blackish-brown. The similarity to a basic color
pattern in each of the Atlantic American species
has been mentioned. In the 14 specimens of 8.
boa examined and reported in table 3 and a few
other specimens that have been examined, the
color pattern is consistent in the absence either
of the reticulating black lines or of continuous
unbroken black lines around saddles that charac-
terize specimens of 8. retifer at all ages. Also
none of the specimens of 8. boa examined have
white spots in the saddles as do all of the specimens
of 8. hesperius examined.

The pattern of spots in S. boa, however, does
vary considerably. The dorsal saddles or their
outlines are obscure in one. specimen, and small
black spots are quite numerous and randomly dis-
tributed over the dorsal and lateral surfaces. In
most of the specimens the saddles and lateral
blotches are outlined by discrete black spots, more
or less round and much smaller than the eye. The
spots extend on to the upper surfaces of the
pectoral and pelvic and are present on the dorsal

REVIEW OF WESTERN ATLANTIC CAT SHARKS

601

fins and on both the upper and lower lobes of the
caudal fin.

Species described as Catulus haeckelii Miranda-
Riheiro, 1907, and as Scyliorhinus fernandezi
Weibezahn, 1953, are regarded here as being syn-
onymous with S. boa. The geographical range of
S. boa extends at least from the continental slope
of central Venezuela eastward and southward to
Rio de Janeiro where it was taken by Miranda-
Ribeiro (1907). Dr. Elvira M. Siccardi has told
me (personal communication) of the presence of
S. boa or a closely allied population off the north-
erly coast of Argentina. A photograph of one
specimen shows somewhat longer and larger black
spots than characterize the specimens seen from
Venezuela and the Guianas. Whether the juvenile
specimen reported by Bigelow and Schroeder
(1948) from the north coast of Cuba is correctly
identified as S. boa now appears questionable.
Material examined in this study in addition to
the type is from 10 stations of the M/V Oregon
off the coasts of Venezuela, the Guianas, and
Brazil, from lat, 11°34' N., long. 62°52' W., to hit.
01°52' N., long. 46°54' W., in 293 to 402 m.

The teeth in S. boa in specimens examined were
from 24 + 24/21 + 1 + 21 to 25 + 25/23 + 1+23. The
teeth were somewhat smaller than the teeth of other
western Atlantic Scyliorhinus of similar size.
Also the central cusps are comparatively shorter,
and nearly all teeth have five cusps, with only teeth
of the central part of the upper jaw having the
middle cusp of each tooth twice as long as the cusps
next to it.

The dermal denticles of the dorsolateral sur-
faces differ from the denticles of S. meadi in being
smaller, wider (some of them nearly as wide as
long), set. closer together, and less erect. The
denticles of 8. boa differ very little from denticles
of other Atlantic American members of the genus.
Denticle differences due to age and perhaps also to
intraspecific variation are so great, however, that
these are probably not ordinarily useful in identi-
fying material.

S. boil seems to he a smaller species than S.
retifer or S. hesperius, since a 346 nun. male is
sexually mature. The claspers of I his male reach
4 mm. past the tips of the pelvics which are united
to one another along their inner margins to within
6 mm. of their tips. The claspers are not provided
with hooks hut have a few slightly enlarged den-

ticles which have points directed anteriorly (to-
ward the base of the claspers) as in the denticle
arrangement on claspers of all galeoid sharks.

Scyliorhinus retifer (Garman), 1881
Figures 2, 5, 6, 7. 8, and 27 ; tables 1. 3, and 4

Soyllium retiferum Garman, Bull. Mus. Comp. Zool.
8:233, 1881 (type locality, lat. 38°23' N., long 73°34'
W.).

This species is easily recognized by its unique
pattern of reticulating lines sometimes reduced to
black edging lines along margins of saddles and
blotches. It is the only Atlantic American cat-
shark known well enough to have acquired an
English common name, the chain dogfish. It is
frequently taken by trawlers operating off the
Virginia Capes.

The known range of the species extends from the
offing of southern New England and the south-
western edge of Georges Bank to Nicaragua.
Bigelow, Schroeder, and Springer (1953) note
that it has been taken at depths of 73 to 229 m.
in the northern part of its range. Specimens of
S. retifer have been seen from more than 100 sta-
tions of Bureau of Commercial Fisheries Explora-
tory Fishing vessels between the Virginia Capes,
the lower Gulf of Campeche, and off central Nica-
ragua (lat. 13°30' N., long. 82°00' W.), along the
continental slope. The station with the least depth
was at 165 m. off Cape Henry, Va., where over
500 juveniles about 160 to 200 mm. long were taken
in early May, 1961. Southward the collections
were at greater depths, for the most part from 330
to 450 m. off Florida and in the Gulf of Mexico,
but 500 to 550 m. off Nicaragua. One specimen
of S. retifer was taken from M/V Oregon station
1883 on the continental slope off Honduras at 365
m. where a specimen of S. hexperius was also taken.
Southward from this station along the continental
slope for a distance of about 200 miles, where the
two forms occupy adjacent or nearly overlapping
ranges, *S'. retifer was taken in an average depth
of 525 m. (460 to 550 m.) at 16 stations, while .V.
hesperius was taken at an average depth of 400
m. (274 to 530 m.) at 7 stations.

A peculiarity of the distribution of S. retifer
is that records of it occurrence on the Antilles!)
side of the Straits of Florida (off Cuba and the
Bahama Banks) are absent. X. torrei records are
chiefly from this area, and one of the three sta-

6(12

U.S. FISH AND WILDLIFE SERVICE

.-..-.5- •■?■■- * . - *ss^v

Figure 15. — A, Scyliorhinus boa (Goode and Bean) drawn from a 348-mni. female from M/V Oregon station
2351; B, Scyliorhinus hesperius new species, drawn from a 260-nim. female from M/V Oregon station
1883.

tions where S. meadi was taken is close to the
Bahama Banks.

Despite the extensive collection of S. retifer
available for study, few of the specimens are
adults. A male, 395 mm. in total length, taken by
the Bureau of Commercial Fisheries M/V Dela-
ware in 128 m. off Delaware Bay, was the only
specimen observed that was determined to 'be sex-
ually mature.

A 475-mm. female taken from 402 m. off Pensa-
cola, Fla,, was the largest specimen examined. The
ovary was extremely small, without evidence of
developing eggs.

The stomach of the 475-mm. specimen contained
12 cephalopod beaks of more than one type.

Teeth of specimens of S. retifer are in 21 + 21/
19 + 2+19 to 26 + 26/21 + 4 + 21 in specimens ex-
amined. In form, the teeth of retifer do not dif-
fer greatly or consistently from teeth of other
Atlantic American species of Scyliorhinus.

Scyliorhinus hesperius new species

Figures 7. 9, 15, and 27 : tables 1, 3, and 4.

Holotype. — An immature female, USNM 187732, 415 mm.
in total length, taken at M/V Oregon station 3598, lat.

09°03' N., long. 81°22' W., at 360- to 400-m. depth on
the Caribbean coast of western Panama, May 31, 1962.
Additional material examined. Twelve specimens, 177
to 466 mm. total length, taken at M/V Oregon stations
1870, 1883, 3522, 3565, 3574, 3575, 3598, 3599, 3626, 4480,
and 4482, all in the western Caribbean from the vicinity of
Jamaica and Honduras, southward to Panama and off Bar-
ranquilla, Columbia, in 274- to 530-m. depth.

Diagnosis. — 8. hesperius resembles 8. boa, 8.
meadi, and 8. retifer in proportions and external
structural features but differs from these species in
having from 2 to about 35 round white spots, small-
er than the diameter of the eye, within each of the
dorsal saddles and lateral blotches. The species
differs from 8. retifer in the absence of reticulating
lines or in the absence of darker margins around
the saddles and blotches. It differs from 8. boa in
the absence of small black marketings either scat-
tered or outlining the saddles and blotches. The
presence of small white spots in 8. hesperhix
separates it from 8. meadi in all the specimens seen.
The. white spots in 8. hesperius are concentrated in
the saddles and blotches and are not more or less
randomly distributed as in 8. torrei.

Description of holotypc. — An immature female,
415 mm. in total length and having dimensions as

REVIEW OF WESTERN ATLANTIC CAT SHARKS

603

given in table 3. Body robust, caudal axis not
elevated; head broad; snout broadly rounded,
short ; nasal flaps rather large, each with a central
swelling dividing each flap into two portions which
cover the two parts of each nasal aperture, sepa-
rated from one another in the midline, nearly
reaching mouth, no groove connecting nasal aper-
tures with mouth; mouth broad, moderately
arched; well-developed labial folds extending a
short distance along the inner sides of lower jaws,
no labial folds along outer margin of upper jaws;
orbital opening elongate, slitlike, a well-developed
fold below eye, not touching eyeball; spiracle
small, located short distance from rear corner of
eye, about same level as eye ; fourth and fifth gill
slits over pectoral base; first dorsal origin over
end of base of pelvics, its area about twice that of
second dorsal ; second dorsal origin slightly in ad-
vance of posterior end of anal fin base; anal fin
origin very slightly posterior to free tip of first
dorsal, its free tip reaching end of base of second
dorsal ; caudal fin less than one- fourth total length ;
pectoral fins broad, short, their distal margins
nearly straight ; pelvic fins united along their inner
margins about half the distance from anus to fin
tips.

Denticles, three-ridged, imbricate, with a single
strong apical (posterior) point with a weak lateral
point on each side, denticle size not uniform, some
twice as large as others.

Teeth similar in upper and lower jaws, small,
in 24 + 0 + 24/22 + 2 + 22 rows; each tooth with 3
or more smooth-edged cusps, the central cusp long-
est, most teeth with two pairs of lateral cusps, the
outer pair very small.

Color pattern of type approximately as illus-
trated for specimen shown in figure 15B.

Schroederichthys new genus
Type species — Schroederichthys maculatus n. sp.

Members of this genus differ from nearly all
other sharks in having the posfpelvic trunk region
in advance of the caudal fin greatly elongated, the
distance from the origin of the pelvics to the origin
<>f the caudal fin lobes about one and three-fourths
times the distance from the tip of the snout to the
origin of the pelvics. In this character of body
proportions, members of the genus St-hrorderirh
thys show a parallel development with some Aus-
tralian sharks of the family Orectolobidae.

particularly Hemiscyllium. These orectolobids,
however, have quite different arrangements of
parts near the mouth and have nasoral grooves
and barbellike structures. In Schroederichthys
also the anal fin is separated from the lower caudal
lobe by a considerable distance (a distance equal
to about two times the length of the base of the
anal), whereas in some orectolobids (Hemiscyl-
r/uw- and related genera) only a notch separates
the anal from the lower caudal lobe.

Schroederichthys differs from ScyJiorhinus in
having definite though short labial grooves along
both upper and lower jaws at the corners of the
mouth. It is similar to the two Chilean-Patago-
nian species provisionally referred to the genus
Halaelurus in having upper labial grooves or folds.
Schroederichthys differs from these species in
having a somewhat longer postpelvic trunk,
shorter labial grooves, and consistently (at all
ages in S. maculatus) multicusped teeth in both
jaws.

Generic description. — Small slender sharks of
the family Scyliorhinidae having greatlv elon-
gated caudal regions with relatively short caudal
fins; distance from tip of snout to vent about half
the distance from vent to tip of tail; caudal axis
little elevated, lower caudal fin not produced as a
lobe; two dorsal fins, second dorsal slightly larger
than first and similar in shape, first originating
behind posterior end of pelvic base; anal fin rela-
tively low, its base longer than base of either dor-'
sal fin; pectoral fins relatively broad, their distal
margins straight or very slightly convex, their
outer corners rounded; pelvic fins with their in-
ner-posterior comers somewhat produced and
their distal margins oblique, pelvics of males
united at bases for a very short distance, not form-
ing an apron.

Snout only moderately rounded; nasal flaps
small but extending across the nasal apertures;
nostrils not united with mouth by a groove and
separated from mouth by a distance as great as or
greater than width of nasal flap; mouth strongly
arched; labial grooves short but extending around
corners of mouth; eye elongate, with well-marked
fold below, not in contact with eye; spiracle small,
on level of eye and close behind it; gill slits five,
anterior longest, two posterior slits over pectoral
base: no ridges or keels in skin, no precaudal pits,
a shallow groove on midventra] line posterior to

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U.S. FISH AND WILDLIFE SERVICE

pelvics and extending, interrupted by anal fin,
nearly to lower caudal fin.

Teeth similar in upper and lower jaws (fig. 9),
principal ones with three or five cusps, central
cusp of each tooth much the longest, three to five
series functional. Dorsolateral denticles (fig.
7F) for the most part imbricate, three pointed,
the central posteriorly directed point much the
longest, ventral denticles leaf-shaped, with a sin-
gle point.

Vertebrae (in 36 specimens) 132 to 142, raono-
spondylous vertebrae 29 to 35.

Type species oviparous, eggshells (fig. 19) with
rather thick walls, their surfaces striated longi-
tudinally, opaque, about 44 mm. by 14 mm., not
including tendrils developed at the four corners.

Claspers of adult males of type species long,
extending well beyond tips of pelvics, their tips
tapered, without hooks; clasper siphons very
large, long, extending under skin of belly as far
forward as axils of pectorals.

Livers relatively small, occupying only the an-
terior half of body cavity in adults.

General pattern of seven dorsal saddles of
darker color showing at least in young; sometimes
obscure in adults in the type species.

The genus is named for William C. Schroeder,
whose careful and pioneering work with Henry
B. Bigelow on cartilaginous fishes contributed

greatly to a renewal of interest in problems relat-
ing to this important group of marine animals.

Schroederichthys maculatus new species

Figures 4, 5, 7, 0, 16, 17, and 19; tables 1, 5, and 6.

Rolotype.— Adult male 328 mm. total length, USNM
185556, collected in shrimp trawl at R/V Orraon
station 1870, August 21, 1957, from about 410 m. ; lat.
16°39' N., long. 82°29' W., in the Caribbean sea NNW
of Cape Graeias a Dios. Honduras.

Paratype. — An adult female 335 mm. in total length,
taken in the same haul with the holotype.

Diagnosis. — Schroederichthys maculatus is
readily distinguished from sharks of all other gen-
era by the proportionately greater length of the
tail region. It differs from the other species of
Schroederichthys described in this paper in color,
in the shape of the nasal flap, which in S. macu-
latus is triangular with a somewhat bilobed distal
margin as compared to the narrower, longer flap
with a simple rounded tip of the other species.
The color differences are so great between the two
species of Schroederichthys that other differences
are of comparatively little interest for practical
identification of the two forms. S. maculatus has
a color pattern almost identical with that of Scyli-
orhinus torrei Howell-Rivero. The dorsal sur-
faces are tan or light brown with round, ovoid, or
irregularly shaped white or cream-colored spots
about 1 to 3 mm. in diameter scattered over the
dorsal surfaces except on the surfaces of the dorsal

— ■ — -*m — . — __ —

Figure 16. — A, Schroederichtliys maculatus new species, drawn from the type, USNM 185556, a 328-mm.
adult male; B, Schroederichthys lenuis new species, drawn from the type, USNM 188052, a 230-mm.
immature male.

REVIEW OF WESTERN ATLANTIC CAT SHARKS 605

795-35S 0—66 6

fins and the paired fins, and with traces of 10
dorsal saddles appearing as areas of somewhat
intensified brown color; these saddles are obscure
or absent anteriorly in some adults. This color
pattern is so close to that of ScyliorMnus torrel
that specimens in a mixed lot of the two species
are not readily distinguishable from one another
on the basis of color. The other species of
Schroederichthys resembles ScyliorMnus boa in
general coloration, having a pattern of dark spots
spots and lines on a lighter background.

Description of the holotype. — The holotype is
shown in figure 16A, and measurements are given
in table 5. Teeth in 24 + 2 + 24/(18 + ) +2 +
(18+) rows; most of them tricuspid but some
with additional small lateral cusps; largest upper
jaw teeth about 0.9 mm. high by 0.7 mm. in great-
est width, central cusp projecting beyond base
about five times length of lateral cusps, edges of
cusps smooth, six or more low surface ridges ex-
tending from bases about half-way toward tips of
cusps; lower jaw teeth similar but central cusps
somewhat lower, length of central cusp of largest
tooth about four times height of lateral cusps, sur-
face ridges very short, present only on lower por-
tion of the bases.

Typical denticles of dorsalateral surfaces about
0.4 mm. long by about 0.2 mm. wide, with three
points directed upward and posteriorly, central
point much the longest, not very close set, with
skin surface showing around each denticle but
points overlapping, imbricate.

Color of dorsolateral surfaces of bod}' light
brown with numerous round or oval spots of
lighter color, about half the length of the eye or
smaller and irregularly scattered; darker brown
dorsal saddles without definite darker edging
present but obscure anteriorly and extending to
fins only as a trace of darker color; no definite
spots on fins; ventral surfaces white, unmarked.

Notes. — Sckroederichthys maculatus is known
from 48 specimens, all from the Caribbean con-
tinental slope of Central America off Honduras
and Nicaragua. The specimens were collected
from depths of 190 to 410 m., most of them near
Rosalind Hank and Quita Sueno Hank. The cap-
ture of more than .'ill specimens in one net haul
suggests that the species is locally abundant.

Figure 17. — Schroederichthys maculatus
new species, ventral side of head of the
type, USNM 185556.

Schroederichthys tenuis new species

Figures 16 and 18 ; tables 1, 5, and 6.

Holotype. — An immature male 230 mm. in total length,
USNM 188052, collected in a shrimp trawl at M/V
Oregon, station 2083 on November 17, 1957, from about
410 m. at lat. 01°49' N, long. 46°48' W., in the Atlan-
tic off the mouth of the Amazon River.

Paratype. — An immature male 180 mm. long, USNM
188053, taken in the same haul with the holotype.

Diagnosis. — Schroederichthys tenuis is known
only from the types, both immature males. There
appear to be no important differences in body
proportions between these specimens and speci-
mens of S. maculatus of comparable size. S. tenuis
is, of course, readily separable from sharks of other
genera. From S. maculatus, it differs greatly in
color pattern. In addition, S. tenuis has a nasal
flap longer than wide, and its tip is simply
rounded, not pointed or bilobed. The typical der-
mal denticles of dorsal surfaces in S. tenuis are
proportionally somewhat narrower than in S. ma-
culatus and more erect. Some have three pos-
teriorly directed points, but many of them lack
lateral points and are needlelike, although usually
showing a central ridge. The color pattern of S.
tenuis is made up of dark spots on a lighter
ground color, the spots assembled to form a series
of dorsal saddles.

Description, of Iwlotype. — The holotype is
shown in fijrure 1BH and measurements are given

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U.S. FISH AND WILDLIFE SERVICE

in table 5. Teeth in 22 + 22/16 + 2+ 16 rows, about
half with three cusps and half with five cusps.
Color of dorsolateral surfaces light brown with-
out lighter colored spots or markings; pattern of
seven dorsal saddles plus several more or less dis-
tinct intermediate saddles edged with broken lines
of darker color, saddles at the first dorsal and sec-
ond dorsal fins more intense and extending across
the fins, caudal fin strongly marked, paired fins
and anal fin only faintly marked.

Figure 18. — Schroederichthys tenuis new
species, ventral side of head of the type.
USNM 188052.

Notes. — The collection of only two specimens of
this species nearly 2,000 miles from the area from
which S. macidatus is known illustrates the incom-
pleteness of the sampling of the fauna from con-
tinental slopes.

Genus Galeus Rafinesque, 1810

Type species — Galeus melastomus Rafinesque, desig-
nated by Fowler, 1908.

Galeus is a genus with about eight nominal
species, one of which, Galeus melastomus Rafin-
esque, of the eastern North Atlantic region, is well
known. Members of the genus are characterized
by the presence of a spiny crest of enlarged den-
ticles on the upper margin of the caudal fin (fig.
21) and a comparatively long snout. An Aus-
tralian scyliorhinid with enlarged denticles form-
ing crests along both the upper margin of the
upper caudal lobe and the anterior margin of the
lower caudal lobe has been split off from Galeus

Figure 19. — Partially formed egg ease of Schroederich-
thys maculatus taken from an oviduct of a 342-mm.
female collected at M/V Oregon station 1870, August 21,
1957. The egg case was 44 mm. long by 14 mm. in
greatest width, and the posterior tendrils (broken off
in drawing) were 225 mm. long. The anterior end of
the egg case was still within the nidamental gland
area when taken, and anterior tendrils had not formed.
The egg case wall was rather thick, opaque, olive
colored, and striated longitudinally.

under the name Figaro boardmani (Whitley). A
group of two Pacific scyliorhinid species, Parma-
turus xaniurus (Gilbert) and P. pilosus Garman,
have crests with specialized denticles along the
upper margin of the caudal fin, but these crests ex-
tend somewhat onto the lateral surface of the up-
per caudal lobe, and the marginal scales, although
enlarged, do not project outward from the tail to
the degree characteristic of these, scales in Galeus.
Also, these sharks, Parmaturus, have compara-
tively short snouts and broad heads, much different
in general shape from members of the genus Gal-
eus. One other cat shark, Apristurus profund-
orum (Goode and Bean), also has denticles on the
upper margin of the dorsal fin differing in size
and shape as well as in spacing from denticles on
the lateral surfaces of the tail and most other parts
of the body (see fig. 23). The crest is less well
defined in Parmaturus than in Galeus, and in
Apristurus profundorum there are no enlarged
and projecting denticles marking the margin of a
crest.

The presence of an upper caudal crest with

REVIEW OF WESTERN ATLANTIC CAT SHARKS

607

much enlarged marginal scales, the crest not ex-
tending appreciably onto the lateral surface of the
tail, appears to be a unique feature of Galeus and
sufficient for diagnosis in the present treatment
of scyliorhinid genera. Other characters, such as
the long and structurally specialized claspers, may
also be useful in the definition of the genus; but
until more Pacific and eastern Atlantic specimens
have been examined, I wish to avoid tampering
with generic definitions and will rely on char-
acters clearly outlined in the literature.

Species of the genus as presently understood
may be divided into two groups on the basis of
color pattern. One group comprises plain colored
species, sometimes with fin markings of contrast-
ing color but. without a pattern of cloudy spots or
blotches generally distributed over dorsolateral
surfaces. Plain colored species are Galeus sauteri
(Jordan and Richardson) of the western Pacific
and Galeus jenseni (Saemundsson) and Galeus
murinus (Collett) of the northeastern Atlantic.
Another western Pacific species, Galeus hertwigi
(Engelhardt ) , said to have a short snout and a tail
with contrasting color pattern, has been included
in the genus Galeus by Fowler (1941).

The other group of the genus is characterized
by the presence of a pattern of blotches or spots
over the dorsolateral surfaces. This group in-
cludes Galeus melastomus Rafinesque of the east-
ern North Atlantic, Galeus polll Cadenat from the
west coast of Africa, and the western Atlantic
forms treated here. In addition, a Pacific species,
Galeus eastmani (Jordan and Snyder, 1904), has
been described as having "indistinct clouds of
deeper shade." It appears from examination of
the type (SIT 7740) that these markings are less
pronounced than in any of the western Atlantic
forms. Galeus eastmani differs markedly from
Atlantic species in being more slender, having a
more sharply pointed snout, having a larger spir-
acle, and in having heavier denticles.

KEY TO ADULT SPECIMENS OF WESTERN
ATLANTIC GALEUS

1A. Anal fin long, its origin under ;i vertical through the
posterior tip of the first dorsal fin and its rear t i I «
nearly reaching (to Within one-halt diameter of the
eye) origin of lower caudal lobe__ Galeus caa\ wait

n. sp.

IB. Anal fin short, its origin in hack of a vertical through
the posterior lip of the first dorsal tin and its rear
tip separated from the origin of the lower caudal

lobe by a distance equal to the horizontal diameter
of the eye or more Galeus arae (Nichols)

Galeus arae (Nichols), 1927

Figures 4, 5, 7, 20, 21, and 27 ; tables 1, 5, and 6.

Galeus arae is a much smaller species than G.
melmtornus of the eastern North Atlantic and
Mediterranean. None of the G. arae seen exceed
37 cm. while G. melastomus reaches a length of
over 90 cm. G. melastomus lays eggs in leathery
cases similar in general appearance to egg cases of
other scyliorhinids. Although adult female G.
arae with large ovarian eggs have been collected,
none have been observed with eggs or embryos in
the oviducts and no egg cases have been collected
that can be referred with confidence to western
Atlantic Galeus.

Galeus arae is very commonly taken in shrimp
trawls off the coast of Florida, both in the Atlantic
and the Gulf of Mexico. Examples have been
recorded for more than 100 stations of exploratory
fishing vessels, usually with several specimens
from each station. Collections from single hauls
indicate strong tendencies to segregation by size
and sex, but no well-defined pattern in the. depth
of occurrence of immature or of adult males or
females has appeared.

The records at hand show Galeus arae to be
locally common from about 330- to 460-m. depth
around Florida, from the offings of Jacksonville
to Pensacola, and usually at greater depths, 400
to 620 m., in the Yucatan Channel, near Pedro
Bank and Jamaica, and around some of the
banks and islands of the Caribbean off the coasts
of Nicaragua and Costa Rica southward to lat.
13°30' N. Three atypical specimens from the
vicinity of Puerto Rico, provisionally referred to
G. arae,, are from 293- and 402-m. depth. The
Puerto Rican specimens are more robust than
the typical G. arae and have a poorly defined pat-
tern of spots (fig. 20C). They may represent an
un described species, but closely resemble G. arae
in morphology and proportions. Larger series
are needed to assess the status of the Puerto Rican
specimens.

Bigelow anil Schroeder (1948), referring to a
series of specimens taken off Tortugas and off the
north coast of Cuba, note that one specimen of
about 295 mm. has claspers falling short of the tip
of the pelvics, wltile in another male of 317 mm.,
the claspers extend far beyond the tips of the

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U.S. FISH AND WILDLIFE SERVICE

lilt

Figure 20. — A, Gale it 8 arae (Nichols), drawn from a 290-inrn. female; B, Galeits cadenati new species, drawn
from a 300-nini. female ; C. Galeits arae, drawn from a 320-mm. female from Puerto Rico, showing color
pattern found on large examples from that area.

pelvics. From this they conclude that maturity
is probably attained at about 300 mm. The ex-
tensive series of G. arae that I have examined in-
cludes large numbers of adult, males from the
Florida and Central American slope. These are
265- to 290-mm. specimens for the most part, and
no examples of either sex exceed 330 mm. The
specimens from Puerto Rico already mentioned
include two adults, a 368-mm. male, and a 352-mm.
female. They are not only appreciably larger than
any observed from the continental slope but also
differ in some body and fin proportions. As
shown in table. 6, the Puerto Rican specimens have
a proportionally shorter anal fin and differ in
other measurements from Florida examples of
G. arae.

Galeus cadenati new species

Figures 20, 21, and 27 ; tables 1, 5. and 6.

Holoti/pe.—A female 303 mm. in total length, USNM
260468, Fl collected at R/V Oregon, station 3592, lat.
09°13' N., long. 80°44' W., in 439-m. depth off the Car-
ibbean coast of Panama, May 30, 1962.

Diagnosis. — A small species of the genus Galeus
differing from G. arae in having a comparatively
longer anal fin (13.2 to 15.0 percent of total length
compared to 8.7 to 13.6 percent in G. arae) with
the tip of the anal reaching nearly to the lower
caudal origin, separated from it only by a distance
less than half the horizontal diameter of the eye
as compared to separation by a distance equal to
the horizontal diameter of the eye or more in G.
arae. The pectoral fins and the two dorsal fins of

REVIEW OF WESTERN ATLANTIC CAT SHARKS

609

Figube 21. — Enlarged scales of caudal crests drawn from
sections near the origin of upper caudal lobes of: A,
Galeus arae; and B, Galeus cadcnati.

G. cadenati are proportionally somewhat, longer
than the fins of G. arae (table 6). Minor differ-
ences in the caudal crest are shown in figure 21, the
crest in G. cadenati being about three-fourths the
width jof the crests in G. arae of comparable size.

This species is similar to Galeus polli Cadenat,
1959, which is found abundantly on the west coast
of Africa. I have compared specimens of the new
species with a large series of G. polli, including
examples from several localities, collected by
vessels of the Guinean Trawling Survey and
loaned to me through the Smithsonian Institution
Sorting Center. Both G. polli and G. cadenati
have long anal fins and are readily separable from
G. arae on this basis. G. polli has a longer snout
(as measured from the front of the mouth) and a
narrower head than G. cadenati, but proportional
differences in snout length and distance between
I he nostrils are not great in all specimens at hand.
In Cadenat's table (1959) of proportions for four

large adult G. polli, distances from the top of the
snout to the front of the mouth are shown as 7.4
to 8.5 percent of total length as compared to 6.0 to
7.3 percent in our specimens of G. cadenati.

Differences between G. polli and G. cadenati
that are not especially notable in comparison of
measurements are easily seen in side by side com-
parison of the two species. G. cadenati has a more
robust form, a wider and shorter head, and a wider
and shorter mouth. The color differences in the
specimens examined are also striking. The speci-
mens of G. cadenati are brown with the spots and
saddles of the posterior part of the trunk rather
indistinct. All of the specimens of G. polli avail-
able for examination are grayish with black or
nearly black spots and saddles. In most of the
specimens the spots and saddles are more clearly
defined ; but a few specimens are dark all over, and
the spots and saddles are indistinct.

Description of the holotype. — Measurements of
the type, TJSNM 260468-F1, are given in table
5, and the color pattern in the type does not differ
appreciably from that illustrated (fig. 20B) for
the species. Body moderately slender, caudal axis
not elevated, body sector (tip snout to anus) about
two-fifths of total length ; head broad, snout mod-
erately pointed and not greatly flattened dorso-
ventrally, with large, medially located, and elon-
gate patches of mucous pores above and below,
the pore openings small, arranged in irregular
rows; nasal apertures large, about half the length
of snout measured to front of mouth, oblique, with
a triangular flap covering the posterior opening
when closed, well separated from mouth; mouth
large with labial grooves above and below, the
lower longer, reaching about one-fourth the dis-
tance toward the symphysis; eye large, oval, length
of orbit more than two times its width, no func-
tional nictitating membrane, but a subocular fold ;
spiracle moderate, located immediately behind and
slightly below level of horizontal axis of eye; gill
openings short, longest about half the horizontal
diameter of eye, the fourth and fifth located above
the origin of the pectoral; pectoral long, about
two times length of snout and broad, its greatest
width about two-thirds the length of its anterior
margin, its distal corners rounded ; first dorsal fin
origin nearly over middle of pelvic base, its distal
margin only slightly convex, its apical and lower
tips moderately rounded; second dorsal fin about

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U.S. FISH AND WILDLIFE SERVICE

as large as first dorsal ; dorsal fin bases separated
by a distance about equal to length of anal base;
second dorsal similar in shape to first dorsal, its
origin posterior to middle of base of anal, its pos-
terior tip separated from origin of caudal crest
by a distance equal to one-half horizontal diameter
of orbit; pelvic fins large and long, united and
adnate to body for a short, distance posterior to
anus, their posterior tips pointed; anal fin long,
its base 2y2 times base of first dorsal, its height
about equal to height of second dorsal; upper
caudal with crest of modified denticles (see fig.
21B), caudal fin slightly less than one-third total
length; lower caudal fin about same height as anal,
its margin rounded without forming a pointed
lobe, a notch near the tip.

Denticles over dorsolateral surfaces small, three
pointed, the central point much the longest, similar
to denticles of G. arae (see fig. 7) .

Teeth relatively small, multicusped, largest
three or five cusped with central cusp much the
longest, similar in shape in upper and lower jaws,
several series functional; upper teeth in 31 + 31
rows; lower teeth in oblique series, not readily
counted by row.

Notes. — Galeus cadenati, so far as known, is
found only in the southwestern Caribbean off the
coast of Panama. Although this is quite near the
range of Galeus arae, which occurs off the coast
of Nicaragua, the collections seen show no over-
lapping.

Eastward and along the Caribbean or Atlantic
coasts of Columbia, Venezuela, the Guianas, and
northern Brazil, specimens of Galeus have not
been reported although collections from these areas
have produced many small sharks of other genera
in depths at which Galeus would be expected to
occur.

Genus Apristurus Garman, 1913

Type species Scylliorhinus indicus Brauer, 1906, by
original designation.

The genus Apristurus as understood here
(Pentanehus profundicollis Smith and Radcliffe
is excluded) contains about 16 species. Four west-
ern Atlantic species are recognized. Members of
the genus are small sharks, for the most part less
than a meter long, with broad and flattened heads
which are sometimes described as shovel-shaped.
All of the known species are rather uniform black
or dark brown in life. Lighter colors on some

museum specimens (Apristurus profundorum) are
thought to be due to handling accidents or to ef-
fects of preservatives.

Various sets of characters have been used in de-
scriptions of species of Apristurus, but most
authors have relied on morphometries to define
species. This has not been very satisfactory be-
cause some descriptions have had to rest on single
specimens and at best the series are small. Added
to this, specimens of Apristurus preserved in
alcohol quickly become wrinkled and fragile.
Measurements are difficult to make, and the body
proportions and fin positions in the series measured
appear to vary considerably within species.

So far as known, all species inhabit deep water,
specimens for the most part being taken from
depths of more than 600 m.

KEY TO WESTERN ATLANTIC APRISTURUS

1A. Denticles over most dorsolateral areas narrow,
erect, not imbricate, their bases separated by dis-
tances greater than the diameter of a denticle base ;
a caudal crest of wide, imbricate denticles of about
uniform size, their tips not pointed upward, form-
ing a rather smooth surface, extending a short dis-
tance onto the lateral surface of the tail, the crest
denticles in sharp contrast (see fig. 23) to the very
sparsely scattered, narrow and erect denticles of
the lateral surface of the tail ; pelvic fins compara-
tively short, somewhat thickened, broadly ovate in
shape; anal fin relatively high, its anterior and
distal margins forming a continuous smooth
curve Apristurus profundorum

IB. Denticles over most dorsolateral surfaces moderate-
ly broad, close together, imbricate or at least very
closely arranged with small spaces between bases;
denticles of upper margin of tail not differing great-
ly in shape, size or density of arrangement from
denticles of lateral surfaces of tail ; pelvic fins com-
paratively long, lanceolate; anal fin either high
or low but with its anterior margin and distal mar-
gin forming an angle, the two margins not rounded
as a continuous curve . 2A or 2B

2A. Head comparatively narrow with narrow band of
prominent mucous pores of underside of snout ex-
tending medially from front of mouth nearly to tip
of snout in four or sometimes six longitudinal rows ;
tip of snout notably constricted at anterior end of
nostrils; teeth comparatively large and sexually
dimorphic Apristurus riveri

2B. Head comparatively broad with a wide band of prom-
inent mucous pores of underside of snout extending
medially from front of mouth nearly to tip of snout
in eight or more longitudinal rows ; tip of snout not
notably narrowed at nostrils ; teeth comparatively
small with no sexual dimorphism 3A or 3B

REVIEW OF WESTERN ATLANTIC CAT SHARKS

611

3A. 'Second dorsal fin substantially greater in area than
first dorsal fin ; first dorsal fin origin usually be-
hind posterior end of base of pelvic fins

Apristurus indicus

3B. First and second dorsal fins of nearly equal area ;
first dorsal fin origin over the middle of the pelvic
base Apristurus laiirussoni

Apristurus profundorum (Goode and Bean), 1896

Figures 7, 22, 23, 25, and 27 ; tables 1, 7, and 8.

The type specimen of .4. profundorum, USNM
35646, is in quite, poor condition and very fragile.
The fins are frayed, the skin looks scuffed, and the
general impression given is that denticles, pieces
of skin, and pieces of fins must be missing. Actu-
ally very little is missing although there is no
doubt that the specimen had been severely dam-
aged either when captured or during 69 years of
its existence as a preserved specimen. Some ques-
tions about this specimen came up during the
course of preparation of a report on sharks (Bige-
low, Schroeder. and Springer, 1953), and if my
memory is correct it fell to my lot to reexamine it.
Apparently my reexamination missed some of the
important features, and I am thus primarily re-
sponsible for failure to note that the material
studied and held to be profundorum in that report
included two species.

A. profundorum is easily separated from the
other three western Atlantic species by the char-
acters given in the preceding key. Several differ-
ences also are evident from table 8 which shows
ranges of measurements in the series examined.
These ranges of measurements show a lesser dis-
tance from the tip of the snout to the origin of the
first dorsal fin than in the other three western At-
lantic species and a lesser distance from the tip of
the snout to the origin of the second dorsal. The
table also shows a wide degree of variation in
proportions for all Apristurus.

The teeth of the type, an adult male, are in
25 + 25/25 + 25 rows, and the teeth of a smaller
female specimen, MCZ 38299, are in 31 + 31/25 + 25
rows. The teeth are difficult to count because they
are arranged in alternate series, and the number of
functional series varies from about five near the
symphysis to three or less at the corners of the jaw.

The type of profundorum was collected from
1,492 m. off Delaware Bay, and the specimens in-
cluded in the series of five specimens measured here
was collected by the M/V Cap^n Bill II at depths
from 686 to 1,317 m. off New Jersey and New
England.

I'm. i re 22. — .1, Apristurus profundorum (Goode and Bean), drawn from a 390-mm. female, MCZ 38299; B,
Apristurus indicus < Brauer), drawn from a 395-mm. female from M/V On-yon station 3586.

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^^^^^^H

Figure 23. —Lateral view of portion of caudal fin of
Apristurus profundorum (Goode and Bean), showing
closely packed denticles on and near the upper margin
of the tin and the widely spaced denticles on the lateral
surfaces of the tail.

Apristurus indicus (Brauer), 1906

Figures 9, 22, and 27 ; tables 1, 7, and 8.

It is clear that the western Atlantic specimens of
Apristurus at hand may be divided into four
groups on the basis of characters given in the pre-
ceding key. Three of these groups of specimens
clearly represent respectively Apristurus profun-
dorum (Goode and Bean), J., riveri Bigelow and
Schroeder, and A. laurussoni (Saemundsson).
The fourth group includes specimens referred to
Apristurus atlanticus (Koefoed) by Bigelow and
Schroeder (1948) and Bigelow, Schroeder, and
Springer ( 1953) . The specimens available for ex-
amination are about 40 examples from the Gulf of
Mexico, the Caribbean, and adjacent Atlantic wa-
ters, most of them immature. All are referred to
Apristurus indicus (Brauer) with some missgiv-
ing because A. indicus has been regarded as
restricted to the Indian Ocean.

Koefoed states (1927) that atlanticus is related
both to profundorum Goode and Bean, and indicus
Brauer, but that it differs in having a larger eye.
From Koefoed's measurements of the type, a 247-
mm. specimen from the Atlantic near Gibraltar, it
can be calculated that the orbit is 4.9 percent of the
total length. Among the specimens referred here

to A. indicus, the orbit is 2.5 to 4.0 percent of the
total length and in available specimens of other
Atlantic species 2.2 to 3.9. Koefoed's figure of the
type of atlanticus (1927, pi. 3, fig. 3) shows the
second dorsal fin only slightly larger in area than
the first. In Western Atlantic specimens of A.
indicus the second dorsal fin has less than half the
area of the first dorsal. Furthermore, Koefoed
specifically states that the first and second dorsal
fins of atlanticus are equally large.

The number of tooth rows in the western North
Atlantic specimens of A. indicus at hand varies
from 33 + 33/33 + 33 to 45 + 45/45 + 45. The teeth
of these specimens are much smaller and more
numerous than in A, profundorum and A. riveri.
Although the teeth of A. laurussoni are slightly
larger than in the A. indicus specimens, the differ-
ence is not great enough to be notable except on
direct comparison of specimens of equal size.

Apristurus riveri Bigelow and Schroeder, 1944

Figures 4, 5, 7, 10, 11, 24, and 27 ; tables 1, 7, and S.

In one haul with a 40-foot shrimp trawl at M/V
Oregon station 3586 off the Caribbean coast of
Panama, five Apristurus of about equal size were
taken. The haul was made in 860 to 914 m. A
temperature determination at the bottom was not
made at this station but in nearby stations the fol-
lowing temperatures were recorded : 366 m., 11.6°
C ; 457 m., 8.8° C ; 750 to 768 m., 5° C. Four of the
specimens collected were adults of A. riveri, one
male and three females. The fifth specimen was
an immature example of A. indicus. Of the three
female riveri, one had short filamentous processes
of egg cases protruding. In all three the cloacal
area was surrounded by a flattened ring of white
tissue. All had large eggs ( 10-12 mm. diameter)
in the single ovary, and one had egg cases with
eggs in both oviducts. The egg cases were about
50 mm. long, not including filaments, and about
15 mm. in greatest width. The shells appeared to
be smooth surfaced. The egg shells were not com-
pletely formed or finished at their inner ends, and
the nature of the processes at the posterior ends
could not be determined, except that they were not
the single tendrils at each corner found in
Scyliorhinus but were more numerous and ar-
ranged as a filamentous fringe across the end of
the case. The cases were greenish, semitranspar-
ent, and with some longitudinal lines of lighter
color.

REVIEW OF WESTERN ATLANTIC CAT SHARKS

613

The uniformly flattened cloacal area was appar-
ent as an unusual feature of the specimens only
when they were fresh or were preserved in forma-
lin. After transfer to alcohol this flattening dis-
appeared.

The presence of an adult male in the haul also
revealed the remarkable difference in tooth size
and shape (fig. 10) between adult males and fe-
males. Although later collections produced an-
other adult male from near Key West, the only
immature specimens seen thus far have been fe-
males, so it has not been determined when the tooth
dimorphism first appears.

The teeth in the six specimens examined are in
24 + 0 + 24/19 + 0 + 19 to 29 + 0 + 29/22 + 0 + 21
rows with no teeth at the symphysis in either jaw.
The teeth of the females are generally tricuspid
in the central portion of the jaws but have five,
seven, or nine cusps toward the angles of the jaws.
The number and shape of the teeth of females of
the series described here are about as described for
A. riveri by Bigelow and Schroeder (1944, 1948).
Using the definition of series of teeth given earlier
in this paper, however, the number of functional
series in riveri is five or six. The tooth arrange-
ment, as in other Apristurus or, for that matter, in
all scyliorhinids, is in alternate series with series

defined as teeth arranged along a single line paral-
lel with the axis of the jaw. This arrangement
gives the appearance of diagonal rows (see fig. 11) .
It may be described also as Bigelow and Schroeder
(1944) have done as an arrangement in quincunx.

In dealing with somewhat larger series than
were available to Bigelow and Schroeder, some
difficulties have appeared in the use of distances
between gill openings and angles formed by the
labial grooves as means for differentiating species,
because of greater variation in the larger series.
Among western Atlantic species the narrower
head of riveri seems the most outstanding and re-
liable criterion for quick identification. The com-
paratively narrower head is shown quite clearly
in figure 27. In riveri the band of pores on the
underside of the snout is consistently narrower
than in other western Atlantic species, generally
being composed of about four rows of pores in-
stead of eight or more.

The claspers of the adult males are rather short,
reaching about 2.3 percent of total length beyond
the tips of the pelvic fins, and quite stout. There
are no hooks. The clasper siphons are also rela-
tively short, extending only about 10 mm. in ad-
vance of the origin of the pelvics.

Figure 24. — A, Apristurus riveri Bigelow and Schroeder, drawn from a 400-mm. female from M/V Oregon
station 3586; B, Apristurus laurussoni (Saemundsson), drawn from a 540-mm. male, MCZ 38406.

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U.S. FISH AND WILDLIFE SERVICE

Apristurus laurussoni (Saemundsson), 1922

Figures 24, 25, and 27 ; tables 1, 7, and 8.

Saemundsson's only specimen, the type of Scyl-
lium laurussonii, was a 673-mm. female. This
specimen, which is in excellent condition, was ex-
amined through the courtesy of the Natural His-
tory Museum, Reykjavik, as a loan. It differs from
the type specimen Goode and Bean of Scyllim-hinus
profundorum, 1896, with respect to characters
given in the preceding key.

The separation of the broadheaded A. laurus-
soni from the narrow-headed A. riven and the
separation of A. laurussoni from A. profundorum
on the basis of the pelvic shape (see fig. 25) or the
denticle distribution problem presents no difficul-
ty except perhaps in very small specimens.

Figure 25. — Diagram to show shapes of pelvci tins : At
left, Apristurus profundorum ; at right, Apristurus la-u-
ru^soni.

A. laurussoni differs from our specimens of A.
indicus in having the two dorsal fins of approxi-
mately equal size. In A. indicus the first dorsal
fin has about half the area of the second. Both
laurussoni and indicus in the material examined
are quite variable in number of tooth rows, num-
ber of vertebrae, and fin positions.

The teeth of A. laurussoni are small and com-
paratively numerous in 34 + 0 + 34/34+0 + 32 to
42 + 0 + 41/53 + 0+43 rows. The two largest males
examined, 520 and 540 mm., are apparently im-
mature, but there is no indication of sexual dimor-
phism in teeth in comparison with a 580-mm.
female or the type, a 673-mm. female. Saemunds-

son (1922) noted that the teeth of the type are in
22 rows on each side of the symphysis. My count
of the teeth of the type specimen is approximately
41 rows on each side. This difference is the result
of a different method of counting rows. The
alternate arrangement of teeth together with their
generally small size makes routine tooth counting
in Apristurus impractical. In many specimens the
diagonal rows are very prominent and seem to be
the logical ones to count. In our specimens if
diagonal rows were counted, the tooth formula
would be close to that given by Saemundsson.

It may be helpful to subsequent workers with
the genus to note that Goode and Bean's type and
only specimen of profoundorum is an adult male
while their illustration (1896, pi. 5, fig. 16) ap-
pears to be a female. Saemundsson's text refer-
ences to illustrations on plate V (1922, pp. 173
and 200) for Pristiurus Jensenii and Scyllium
Laurussonii are reversed, and the illustration of
the lateral view of a shark in Bigelow and Schroe-
der (1948, fig. 38) captioned as the type of
profundorum may not represent that species since
the illustration shows either a female or a male
with claspers not showing, while the type is a male
with claspers extending past the tips of the pelvics.

Exclusive of the type which was collected from
560-m. depth near Vestmanneyjar, off the south-
ern coast of Iceland, I have examined about 25
specimens that I refer to the species. These are
from the northern half of the Gulf of Mexico and
from the Atlantic coast of the United States from
latitude 40°40' N. (off Massachusetts) southward
to 38°41' N. (off Delaware). Specimens were
taken from depths of 760 to 1,460 meters.

Genus Halaelurus Gill, 1861

Type species — Seyllium biirgeri Miiller and Henle, 1841,
by original designation.

The group of scyliorhinid sharks usually as-
sembled in the genus Halaelurus seems to include
leftovers and poorly known species. It is in
special need of nomenclatural revision. Changes
can best be made in a general revision of the
world's scyliorhinid genera, which will require
more extensive collections than are available now.

The American representatives of Halaelurus
have long and strong labial grooves along both up-
per and lower jaws and thus differ from American
species of the genus Scyliorhinus which have weak
and short labial folds only on the lower jaw. The

REVIEW OF WESTERN ATLANTIC CAT SHARKS

615

two South American species considered here both
have patterns of dorsal saddles somewhat resem-
bling those in Scyliorhinus and from this feature
can be readily separated from Apristwrus. They

have no caudal crests and so differ from Gateus.
They differ from Schroede?-u;hthys in having
caudal trunk sections somewhat shorter, in having
much longer and more prominent labial folds, and

I'k.i its 26. — A, Halaclitritx chilensis (Miiller and Henle), an immature male collected at Coquimbo Ray, at lat.
29°56' S., on the coast of Chile (the pelvic tin of this specimen has heen damaged) : B, Halaelurus
bivius (Guichenot), collected near Puerto Montt. Chile, at lat. 41°54' S.

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U.S. FISH AND WILDLIFE SERVICE

in having a reduction (in the. larger specimens ex-
amined) in the number and size of the accessory
cusps on the teeth of the lower jaw.

In many features the Halaelwrus of the southern

part of South America resembles Schroederieh-
thys. Dr. Elvira Siccardi who has examined
many specimens from Argentina has called my at-
tention (in personal communication) to several

Figure 27. — Photographs of lower side of heads: A, Scyliorliinus torrei; B, Scyliorhinus retif&r; C, Scylior-
hinus meadi; D, Scyliorhinus hesperius; E, Scyliorliinus boa; F, Galeus arae; G, Galeus cadenati; H,
Galeus arae; I, Apristurus profundorum; J, Apristurus riven; K, Apristurus laurussoni ; L, Apristurus

indicus.

REVIEW OF WESTERN ATLANTIC CAT SHARKS

617

similarities such as the development of long, very
slender nasal flaps in species of each genus {H.
bivius and S. tenuis), the relatively short caudal
lobes in combination with long postpelvic trunk in
both groups, and certain somewhat subtle similari-
ties in denticle structure.

Problems in connection with names to be ap-
plied to South American Halaelurus cannot be ade-
quately treated here because of insufficient study
material. My view that more species than Hala-
elurus chilensis (Guichenot, 1847) and HalaeVwrus
bivius (Muller and and Henle, 1841) are involved
in the material described by various authors has
been strengthened by discussions with Dr. Sic-
cardi.

Some unresolved questions on the status of types
add to the difficulties with nomenclature. The
types of both H. bivius and H. chilensis are stuffed
specimens. The specimen designated as the type
of bivius by Giinther (1870) is said to be from
southwest. Africa but Gunther's description is not
in close agreement with the earlier description of
Muller and Henle (1841). The confusing synon-
omy of bivius can be seen in the treatment given
in Norman's work (1937) on Patagonian fishes.

It seems probable that all of the accounts of
South American Halaelurus, including this one,
have been based on material quite inadequate to
delineate species. Available material suggests
that considerable differences in some characters
may exist between young and adults of the same
species. This makes the development of meaning-
ful synonymy impractical. It is possible that
both Berg (1895) and Lahille (1921, 1928) dis-
cussed the form here referred to H. chilensis under
the name bivium or bivius. Vaillant's account
(1891), under Scyllium chilense Guichenot, states
that he believes Scyllium bivhim Smith is not a
distinct species, but goes on to state that all the
small examples he had seen were females.

A more extensive study of these scyliorhinids
should provide some answers of great interest to
the phylogeny of carcharhinid sharks because
these sharks, perhaps considered together with
Schroederirhlhi/s, have more characters approach-
ing the carcharhinid line than do other scylior-
hinids. The longer jaw of H. bivius together
with lower jaw spikelike teeth is a feature more
familiar in the Carcharhinidae than in the Scylior-
hinidae. The claspers and clasper siphons of

Schroederichthys bear many resemblances to those
of the carcharhinids.

Halaelurus bivius (Muller and Henle), 1841

Figure 26; tables 7 and 8.

The specimens of H. bivius from Chile examined
for this report are very easily separated from
Chilean examples of H. chilensis by differences in
general shape. As can be seen in the photographs
(fig. 26), H. chilensis has a shorter head, a some-
what shorter and definitely less pointed snout, and
a shorter and much less strongly arched jaw.

The specimens of H. chilensis examined were im-
mature, showing a well-marked series of enlarged
denticles in rows along the back, and in this dif-
fered from the adult H. bivius available for com-
parison. The specimens of H. bivius, however,
had some enlarged dorsolateral denticles.

In direct comparison of H. bivius with H. chU-
ensis specimens, it was noted that the nasal flaps
of H. bivius were longer and narrower, the gill
slits were somewhat longer, the anal fin base was
somewhat longer (see table 7 and 8) , and the denti-
cles prevalent on dorsolateral surfaces had longer
points.

Halaelurus chilensis (Guichenot), 1847

Figure 26 ; tables 7 and 8.

Based on specimens from the Pacific coast of
South America, it appears that there are relatively
great differences between H. chilensis and H. ,
bivius. It should be noted, however, that all of
the specimens of H. bivius seen were adult males
while all the specimens referred to H. chilensis
were immature.

SUMMARY AND COMMENT

To have accomplished its purpose, this study
should have indicated some of the kinds of infor-
mation about catsharks needed for an adequate
revision of the family. Great variation within
species, particularly in morphometries, the occur-
rence of sexual dimorphism (at least in one
species) , and the finding of a new genus and several
new species point to the need for more comprehen-
sive collections from the continental slopes and
from ocean basins as a basis for understanding
the group.

Western Atlantic scyliorhinids all have been
taken at depths where relatively cool temperatures
prevail ; and in the course of a more general study
of the group, if will be interesting to note which,

618

U.S. FISH AND WILDLIFE SERVICE

if any, species enter relatively warmer areas or
shallow-water areas. The discovery by Poll
(1951) and Cadenat (1959) that the ovoviviparous
condition and the oviparous condition both occur
within a single genus (Galeus) points to the need
for much more observation on life histories of
catsharks.

The order in which genera are taken up in this
paper is not intended to have any phylogenetic
implication. Galeus, Apristurus, and Schroede-
richthys, as far as these are known at present, are
quite compact groups of similar species and are
separable from each other and from other of the
world's scyliorhinid genera by many differences.

The separation of Scyliorhimts from Halaslurus
and from some other genera of the Indo-Pacific
region has, in the past, been based primarily upon
differences in the arrangement of skin folds near
the mouth, by the presence or absence of nasoral
grooves, and by the relative development of anter-
ior and posterior nasal valves. Keys to genera and
also to species used by Garman (1913) and by
Fowler (1941) emphasize these characters. I have
given little descriptive space to them because they
appear to be of little use for determination of west-

ern Atlantic species and also because they are some-
what variable in the specimens at hand. I have
also had some difficulty in understanding the ter-
minology. For example, Garman (1913) states
that nasal cirri are absent or rudimentary in
Scyliorhmus, but he separates Poroderma, an
Indian Ocean genus, from Scyliorkinus in his
key by the complete absence in Poroderma of a
rudimentary nasal cirrus. This rudimentary cir-
rus, in the material I have examined, is merely
a thickening of a portion of the anterior nasal
flap, broader and thicker near the base of the flap,
narrower and thinner near the posterior margin
of the flap, but not extending at all beyond the
edge of the flap. If one is familiar with the shape
of nasal cirri of orectolobid sharks, this structure
looks like a nasal cirrus entirely embedded in the
flap. I find it difficult to accept the idea that this
is necessarily a rudimentary structure and suspect
that it may function in directing the flow of water
past the nasal aperture.

Nevertheless, differences in skin structures near
the mouth and nasal apertures may be of great
usefulness in the practical description of species
and as criteria for their identification, especially
among Indo-Pacific forms.

Table 3. — Measurements c

/ selected examples and

type specimens of Atlantic Scyliorhinus

S. retifer
ORE 4163

S. meadi

(type)

USNM 188049

S. hesperius

(type)
USNM 187732

S. boa
USNM 186195

S. torrei
SB 2457

S. canicidus
USNM 195861

USNM 34352

Mm.

465

237

194

282

314

346

354

203

108

Mm.

247

116

107

143

153

180

185

112

Mm.

415

210

176

252

283

315

320

190

Mm.

346

180

145

213

238

268

274

155

Mm.

270

140

105

162

188

210

215

114

Mm.

383

182

148

213

251

292

298

156

Mm.

370

Tip of snout to —

Eye

OiU I

Gill V

185

160

220

242

275

285

170

20
9
4
9
71
44
106
70
45
34
30
3

22
9
9
4
20
69
21
100
46
33
27
27
3

Height gill I„__

Height gill V

REVIEW OF WESTERN ATLANTIC CAT SHARKS

619

Table 4. — Range of total lengths and range of measurements expressed as percent of total length in western Atlantic Scyliorhinus

Species...

Number of specimens measured.
Length range in millimeters

S. retifer

10
173-465

S. meadi

5
183-264

S. hesperius

16*466

S. boa

143-34S

S. torrei

7
129-270

Tip of snout to —

Anterior nasal aperture

Posterior nasal aperture

Front mouth. _

Eye

Gill I

Gill V

Origin pectoral

First dorsal fin

Pelvic fins

Anal fin

Second dorsal fin

Lower caudal fin

Upper caudal fin

Anus

Length upper caudal fin

Base first dorsal fin

Base second dorsal fin

Base anal fin

Distance between dorsal fins

Intemasal distance.

Length orbit -.

Length lower labial fold

Length upper labial fold

Width mouth

Length mouth

Height gill I.

Height gill V

Tip second dorsal to caudal

Tip pelvic to second dorsal

Tip pelvic to anal

Tip pelvic to lower caudal

Length outer margin pectoral

Length anterior margin first dorsal

Length anterior margin second dorsal.

Length anterior margin anal...

Distance eye to spiracle.

Percent

2.3-3.4

3.6-4.7

4.4-5.8

4.5-6.1

14.1-16.5

18. 1-22. 2

16. 4-20. 7

45. 7-51. 1

39.6-41.8

56. 5-60. 7

62. 5-67. 5

72. 3-76. 7

71.7-78.2

41.0-44.4

21.6-25.4

5. 5- 7. 0

4.5-5.8

7.2- 9.1

10.6-11.9

1.5-2.3

3.2- 4.3

1.3-2.1

Percent

3.0-3.8

4.2- 4.5

4.4-4.9

5.3-6.0

13.1-15.8

18.6-21.6

16. 7-20. 0

4r, :', -is. .-,

40.4-42.1

55. 7-57. 6

62.8-64.8

71. 5-75. 0

73. 6-75. 9

43.2-45.5

25.2-28.0

5. 8- 6. 8

5.3-6.3

7. 8- 9. 5

10.5-11.6

5. 8- 6. 8

2.6-3.8

1.6- 2.3

Percent
2.3-4.0

3. 7- 5. 1

4. 5- 5. 7

5. 0- 6. 8
14.5-16.6
18.9-21.5
17. 7-19. 8
46. 9-53. 7
39. 5-44. 4
54.4-62.5

t,i 8-tw i

73. 0-77. 4

74. 4-79. 3

41.2-51.0

20. 7-27. 5

5. 6- 6. 7

4.3-5.2

7.2- 9.2

9.2-11.3

1. 7- 2. 7

3. 1- 4. 7
0.9- 1.9

Percent

2.5-3.5

3.8-4.9

4. 2- 5. 6

5.2- 6.3

13. 7-16. 0

18. 0-20. 4

16. 2-18. 8

45.5-52.0

38. 9-41. 9

53.8-61.6

63.6-68.9

72. 7-78. 2

74. 8-79. 5

40. 1-44. 8

19.9-25.2

5. 4- 6. 8

4. 4- 5. 8

7. 2- 9. 3

10. 3-13. 7

1.8- 2.8

2.9-4.3

0.4- 1.8

6. 3- 8. 1
2.8-4.5
1.6- 2.3
0.6-1.2
1.8-3.7
13.6-15.9
6.8-10.7
21.3-25.6
11.4-15.0
8. 1-10. 0
5. 7- 7. 7
5.3-8.2
0.4-1.2

7.4-8.9

3. 3- 4. 3

1.1- 2.6

0.5- 1.3

2. 7- 4. 7

10.5-13.2

5.8-8.4

21.1-25.0

10.9-13.6

8. 8-10. 6

6. 8- 8. 7

6 8-9.1

1.1- 1.6

6. 9- 8. 8
3. 3- 4. 4
1.5-2.5
0.6- 1.5
1.7- 4.2
9.6-15.4
4.3-10.2

20. 8-25. 4
10. 7-14. 9

7. 5-10. 1

5. 7- 8. 2

5.8- 9.2
0.7- 1.5

5. 8- 7. 8

2.8-4.0

1.3-1.9

0.6-1.2

2.0-4.9

13.0-16.3

6.3-11.5

22.3-26.6

11.8-13.7

8. 0-10. 4

5. 4- 7. 9

6. 9- 8. 3

0. 7- 1. 3

Percent
1.4- 2.2
2.7- 3.9
3. 5- 4. 7

4. 1- 6. 4
13.0-14.7
16. 4-18. 0
15.4-17.2
44.9-51.8
33.2-39.5
54.2-60.0
63. 6-69. 6
73. 6-78. 5
75.2-79.6
37.9-42.2
20. 4-24. 0

5.9-7.0

4.2- 4.7
7.3-9.4

10. 9-14. 5
1.6-2.3
3. 1- 3. 5
1.2-2.0

6. 1- 7. 8

3.5- 5.5

1.6- 2.3
0.2- 1.2
2 7- 4.7

14.7-18.2
6. 2-10. 1

24.6-28.2
8.5-11.3
7. 8- 8. 6

4.2- 5.7
5.5-7.4
0. 7- 1. 2

Table 5. — Measurements of type specimens of Schroederichthys, Galeus cadenati and selected examples of Galeus arae

S. maciUatus

(type)
USNM 185556

S. tenuis

(type)

USNM 188052

Galeus arae
S.B. 2458

Q. arae

USNM 1981o4

(type)
ORE 3592

Totallength.. .

Mm.

328

126

100

172

201

260

265

104

135

Mm.

230

120

136

179

182

Mm.

290

131

115

165

183

210

206

126

Mm.

368

156

144

214

233

270

267

162

100

Mm.
303

Tip of snout to—

Eye..

Gill I

GillV

133

109

151

186

210

120

5.5

Width mouth

Height gill I

Height gill V

620

U.S. FISH AND WILDLIFE SERVICE

Table 6. — Range of total lengths and measurements expressed as percent of total length in Schroederichthys

and Galeus

S. maculatus

■S. tenuis

Qaleus arae

Q. arae

Q. cadenati

0. melastomut

145-342

180-230

190-321

269-368

273-348

313-635

Tip of snout to —

Percent
1.4- 2.4
2.4-3.9

3.1- 4.7

3. 7- 5. 2
9. 9-13. 1

12.9-17.0
12. 0-16. 3
34. 7-40. 8
28. 9-33. 6
49. 4-54. 5
58.3-62.6
77. 5-82. 8
79. 3-83. 5
28. 7-36, 4
15. 9-20. 7
3. 5- 5. 1

5.2- 8.1
6.6-9.0

17.2-20.0
1.9- 2.5

2. 7- 3. 5
0.8- 1.7
0.6- 1.2
5.2- 6.8
1.8-3.9
1.2- 2.1
0.3-0.7
9.6-12.9

18. 4-23. 1
9. 3-13. 4

37.2-42.0
8.2-11.8
6. 1- 8. 4

6. 8- 9. 9

3. 4- 6. 8
0.5-1.5

Percent
1.3- 1.7
3.0-3.3
3.9- 3.9

4. 4- 4. 4
10.4-11.1
13. 9-14. 4
13. 0-13. 3
34. 4-35. 6
29.4-30.0
49.4-52.2
57.2-59.2
77. 7-77. 8
79. 1-79. 4
30. 5-30. 9
16. 5-20. 5

4.4-4.4
6. 1- 6. 5

7. 8- 9. 1
18. 3-19. 4

2.4-2.5
3.0-3.1
1.7- 1.7
1.3-1.7

5. 7- 6. 1
2.6- 2.8

1.1- 1.7
0.4-0.7

10.4-12.2
19. 4-20. 4
12.2-13.1
40.0-40.0
9.4-9.6

7.2- 7.8

8. 7- 8. 9
6.1- 7.2
0. 8- 0. 9

Percent

3. 1- 4. 1
4.3-5.2
5.3-7.1
5.3-7.5

13. 8-16. 0
16. 3-19. 8
15.3-19.3
42. 4-17. 3
37.2-42.0
50. 9-56. 9
59. 0-67-7
68. 8-74. 1
67.5-72.0
39. 8-46. 3
28.0-31.6

4.2- 5.9

4. 4- 6. 7
10.3-13.6
11.3-12.9

2.5-3.3
3.4- 3.9
1.4- 2.2
1.0-1.5
6.2- 7.5
3.2- 4.3
1.3-2.1
0.6-1.3
0.2- 1.5
8.8-12.6
1.6-6.7
18.4-21.7
10.5-12.2
7.2- 8.3
7. 0- 8. 0

5. 5- 8. 0
0.8-1.5

Percent

3. 4- 3. 9

4.5- 5.2

6. 0- 6. 9
5.9-7.8

14. 9-16. 7
20. 1-20. 7
19. 0-20. 1
40. 9-43. 4
34. 6-39. 1
52.7-58.2
59. 8-63. 3
68. 8-74. 7
68. 4-74. 5
39. 8-44. 0
26.2-30.1
4. 3- 5. 1

4.1- 5.2
8. 7- 9. 5

14. 1-16. 6

3. 0- 3. 3

3. 1- 3. 7

1.7- 2.6
1.4-2.0
7.1- 9.2
3.0-4.1
1.1- 1.7
0.6-1.1
1.5- 2.7

10.4-13.3

4.8- 7.1
19.7-22.0

9.9-11.9
6.3-7.9
6.1- 6.9
5. 7- 6. 2
0.9- 1.6

Percent
3.2- 6.1
4.6-5.8
6.0-7.3
6.3-7.6
15. 5-18. 5
18.2-22.2
16.7-21.8
43.2-17.9
34.5-40.2
49. 8-55. 6
60. 1-64. 7
69. 0-75. 1
69. 3-75. 1
39. 5-46. 5
24. 5-29. 7
4. 9- 6. 3
5. 0- 6. 3
13.2-15.0
12.3-14.7
2.4- 3.2

3. 0- 4. 0
1.6- 2.2
1.3-1.7
6.6-9.1
3.2- 5.5
1.3-2.1
0.7- 1.3
0.0-2.2
9.8-11.9
0.7- 3.2

17.9-22.6
12.9-15.6
8. 5-10. 5
7.9-9.2
6. 4- 8. 6

1.1- 1.4

Percent
3.2- 4.8

4.2- 6.7

6.3- 8.6

6.3- 8.3

Gill I

12. 6-17. 5

Gill V - -- -

17.2-23.0

16.7-22.1

44.9-48.2

36. 9-39. 6

62. 1-53. 9

61. 6-63. 9

69.4-70.6

70.0-72.6

40.3-42.8

27.9-30.2

4. 4- 5. 1

4. 6- 5. 4

12.8-15.5

10.9-14.0

2.4-3.5

3. 6- 4. 6

1.3- 1.9

1.0- 1.6

6.2- 7.9

3. 3- 5. 4

Height gill I -

1.9-2.8

Heightgill V

0.9-1.4

0.5-1.3

10.2-14.2

1.3-3.6

19, 5-20. 4

11.9-13.2

7. 7- 8. 9

7.6- 8.9

6.4- 8.1

0.7- 1.3

Table 7. — Measurements of a type specimen of Apristurus and of selected examples of Apristurus and Halaelurus

Museum No. or other designation.

A. profundorum
MCZ 38299

A. indicus
ORE 3654

A. riveri
ORE 3586

A. lauruasoni
MCZ 38406

H. bivius

Coast Chile

42° S.

H. ch'lensis

Coast Chile

30° S.

Total length

Tip of snout to —

Anterior nasal aperture

Posterior nasal aperture

Front mouth

Eye

GUI I

GillV

Origin pectoral

First dorsal fin

Pelvic fins

Anal fin -

Second dorsal fin

Lower caudal fin

Upper caudal fin

Anus

Length upper caudal fin

Base first dorsal fin __

Base second dorsal fin

Base anal fin

Distance between dorsal fins

Internasal distance

Length orbit

Lenth lower labial fold

Length upper labial fold

Width mouth

Length mouth

Height gill I

Height gill V

Tip second dorsal to caudal

Tip pelvic to second dorsal

Tip pelvic to anal

Tip pelvic to lower caudal

Length outer margin pectoral

Length anterior margin first dorsal

Length anterior margin second dorsal.

Length anterior margin anal

Distance eye to spiracle

Mm.

390

104

170

150

192

212

243

253

164

115

-10

Mm.

303

152

125

151

185

206

210

139

-3

-4

Mm.

430

109

105

210

180

230

270

296

308

195

123

Mm.

540

110

130

124

252

230

295

338

378

390

257

148

"44

Mm.

100
128
120
270

55
68
64
140

509

260

116

100

293

135

45
40
45
27

REVIEW OF WESTEiRN ATLANTIC CAT SHARKS
795-358 O— 66 7

621

Table 8. — Range of total lengths and measurements expressed as percent of total length in Apristurus and Halaelurus

A.profundorum

A. indicus

A. river i

A. laurussoni

H. bivius

230-390

235-475

338-460

212-580

555-625

365-392

Tip of snout to —

Percent
4. 8- 7. 2

7. 4-10. 4

8. 7-10. 9
10. 9-13. 0
19. 1-22. 8
23. 5-26. 7
23. 0-26. 4
40. 9-43. 6
38.3-41.6
46. 1-50. 8
53. 9-58. 3
61. 3-64. 4
64. 8-66. 9
42. CM4. 3
29. 5-33. 5

4.8- 7.0
6. 5- 7. 4

13. 2-14. 8
6. 0- 9. 6
3. 6- 4. 8
2. 2- 3. 3
2. 0- 3. 8
1.6-2.8
5. 7- 8. 7

3. 9- 5. 1
0. 9- 2. 0
0.9-1.6

Percent

4. 2- 5. 9

6. 6- 9. 3

7.6-11.2

8.4-11.9

16. 8-22. 0

21. 5-25. 8

20. 2-25. 1

47. 9-51. 8

38. 2-42. 7

49. 5-53. 6

58.5-63.6

65. 6-71. 8

67. 2-72. 6

42. 8-49. 6

29. 3-32. 2

3. 4- 4. 8

5. 0- 6. 8

13. 5-18. 3

6. 0- 8. 8
3. 7- 4. 7

2. 5- 4. 0
1. 6- 2. 6
1. 9- 3. 9
6. 3- 9. 4

3. 3- 4. 8
1. 0- 2. 2
0.4-1.3
0 - 1.3
6. 7-12. 6

-1.6- 2.5

14. 9-18. 1
8.4-11.6
». 2- 7. 5
7. 2- 9. 7
5. 8- 9. 1
0.8- 1.3

Percent

4. 7- 6. 3
6. 5- 8. 3
7. 4-10. 0

10.0-11.8
18. 3-21. 3
22. 2-25. 3
21. 0-24. 4
45. 6-48. 9
39. 4-42. 7
47. 9-53. 6
56. 8-62. 8
64.5-68.8
65. 1-71. 6
43. 5-47. 7
28. 3-32. 1
3. 3- 4. 4

5. 4- 6. 8
13. 0-18. 0

5. 9- 8. 9
3. 7- 4. 3
3. 3- 3. 5
2. 2- 2. 8

2. 2- 2. 7
5. 3- 7. 3

3. 2- 5. 2
2. 2- 2. 6
0.9- 1.9
0-3.5
7.4-11.5
0 - 2.0

14. 8-16. 3
9.8-11.9

5. 4- 7. 4
8.4-11.0

6. 5- 8. 1
0. 9- 1. 2

Percent
3. 8- 5. 4

6. 1- 8. 3

7. 5- 9. 6
8.0-11.5

17.0-21.4
22. 2-26. 8
21. 6-25. 8
43. 4-51. 2
40. 1-47. 8
47. 6-57. 9
59. 0-67. 2
63. 6-72. 4
66. 0-79. 3
42. 9-51. 2
25.9-31.0
4.5-6.6
4. 8- 7. 3
13. 8-16. 9

8. 7-10. 8
3. 6- 5. 0
2. 7- 3. 9
2. 1- 3. 2
3. 1- 3. 9
6. 1-10. 0
3.3- 5.9
0. 8- 2. 3
0. 5- 1. 1
0 - 1.8

6. 6-10. 8
0-1.7

14. 1-18. 4
8. 3-13. 0
7. 1- 9. 3

7. 4- 9. 9
7. 1- 9. 3
0. 9- 1. 2

Percent

3. 5- 3. 8

3.3-3.3

Eye _ ___ ...

Gill I

15. 1-16. 0
18. 4-20. 5
18. 0-19. 2
40. 5-43. 2

15. 2-16. 6

GiUV

18. 3-21. 4

17. 5-20. 4

38. 4-38. 6

78. 0-81. 4
37. 9-40. 0
18. 6-22. 0
5. 6- 6. 2
6. 7- 8. 3
9. 4- 9. 9
16. 0-16. 2

2. 3- 2. 7
2. 7- 2. 9
2. 2- 2. 7
2. 7- 3. 2
5. 8- 6. 4
5. 0- 5. 6

1.4- 1.6
0. 7- 1. 0

74. 7-80. 3

37. 0-38. 2

19. 7-20. 2

7.4- 7.7

8. 8- 9. 2

7. 9- 8. 9

16. 4-16. 6

2.0- 2.2

2. 7- 2. 8

2. 2- 2. 6

Width mouth _

7. 4- 7. 7

Length mouth.. ..

Height gill I

3. 6- 3. 6
1.6-2.0

Height giUV

0. 1- 1. 3

5. 2- 9. 3
-3. 0- 2. 0
13.0-16.2
8. 8-10. 9
7. 0- 8. 9
7.8-11.5
6. 1- 6. 0
0. 9- 1. 6

11.7-12.2
9. 0-10. 2

10. 9-12. 6
7. 4- 7. 5

12.0-12.3

10.4-11.0

12. 0-12. 3

7.4-8.2

A look at the literature on scyliorhinids of the
Indo- Pacific and an examination of very few speci-
mens suggests that studies of Indo-Pacific species
will provide a better basis for estimates of phylo-
genetic relationhips than can be made from At-
lantic species alone. The Atlantic material does
suggest, however, that more detailed study of den-
tition would be desirable, especially with attention
to tooth development. For this review no positive
evidence on scyliorhinid migration and very little
information on habit patterns were found. Fur-
ther studies of species found in the higher latitudes
off South America appear most promising for esti-
mating the course of scyliorhinid phylogeny.

ACKNOWLEDGEMENTS

Work on this paper was started in 1957 when
the intention was to describe a new species of
Scyliorhinus from the single specimen of that
species then known. An illustration of this
specimen was prepared at the time by Nancy
Mead and is used here. Additional material be-
came available later, requiring description of
other new species. Illustrations of several of

these were prepared by Mildred Carrington.
With a decision to expand the paper to cover cat-
sharks of the western Atlantic region, other illus-
trations were prepared by Mary Wagner.

Examinations of type material by Dr. Daniel
M. Cohen and radiographs prepared by staff tech-
nicians at the Bureau of Commercial Fisheries
Ichthyological Laboratory in Washington, D.C.,
helped me reach an opinion on the status of Apris-
turus profwndorum (Goode and Bean).

I am especially indebted to Finnur Gudmunds-
son, Director of the Museum of Natural History,
Reykjavik, for arranging the loan of Saemunds-
son's type of Scylliwm laurussomi, and to F. Wil-
liams, Director, Guinean Trawling Survey, for the
loan of specimens of scyliorhinids from the west,
coast of Africa.

Photographs of Halaelurus bivius and H. chi-
lensis included in this paper were made by
Smithsonian Institution staff photographers.
One photograph of jaws of Apristurus riverl was
made by Ruth Ortman, and a photograph of tooth
arrangement in Pristiophtmis was made by staff

622

U.S. FISH AND WILDLIFE SERVICE

photographers of the Los Angeles County
Museum.

Suggestions and comments on a draft of this
paper received from Shelton P. Applegate, E. A.
Best, Harvey R. Bullis, Daniel M. Cohen. Giles
Mead, O. E. Sette, Elvira M. Siccardi, and John
Thompson are gratefully acknowledged.

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REVIEW OF WESTERN ATLANTIC CAT SHARKS
795-358 0^66 8

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1936. Some new, rare and little-known fishes from
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1905. Description de quelques parties du squelette
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KOFOED, ElNAB.

1927. Fishes from the sea -bottom from the Michael
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1921. Enumeraci6n de los Pesces Cartilaginosus
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1926-1928. Nota sobre unos peces elasmobranquios.

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1920. The comparative morphology of the secondary

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Morph. 34 (2) : 245-265.

1922. The comparative morphology of the secondary
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220.

1924. The comparative morphology of the secondary
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623

1926. The comparative morphology of the secondary
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1926. The comparative morphology of the secondary
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claspers, clasper siphons, and clasper glands.
Mem. X. J. Morph. Phys. 42 (1) : 335-348.

Leriche, Maurice.

1905. Les poissons Eocenes de la Belgique. Mem.
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11 : 49-228.

MlRANDA-RlBEIRO, ALIPIO DE.

1907. Fauna Braziliense. Peixes. Arch. Mus. Nac.
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1841. Systematische Beschreibung der Plagiostomen.
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1927. A new shark from the continental slope off
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Norman, J. R.

1937. Coast Fishes. Part II, The Patagonian
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Poll, Max.

1951. Poissons, I Generalities. II. S^lachiens et
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1810. Caratteri di Alcuni Nuovi Generi e Nuove
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1922. Zoologiske Meddelelser fra Island. Vidensk
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Schmidt, Peteb J.

1930. A selachian clasper with a hundred hooks.
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1912. Description of a new notidanoid shark from
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1949. The sea fishes of Southern Africa. Central
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1960. Natural history of the sandbar shark, Eulamia
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1953. Una nueva especie de Seyliorhinus de Vene-
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624

U.S. FISH AND WILDLIFE SERVICE

SURVEY OF PELAGIC FISHES OF THE CALIFORNIA CURRENT AREA

By Frederick H. Berry,* Research Systematic Zoologist, and Herbert C. Perkins,** Fishery Technician, Bureau
of Commercial Fisheries California Current Resources Laboratory, La Jolla, Calif.

ABSTRACT

The pelagic fishes off central California to central
Baja California were surveyed with four kinds of nekton-
collecting nets. Construction and operation of one of
these nets, the collapsible midwater beam trawl, are
described. The survey was made during eight cruises
between May 1961 and March 1963. More than 189
fish species and about 52,000 specimens were taken.

The number and size range of specimens at each station
of capture are listed for all the species; charts of the
location of capture are given for most species; and
several species are illustrated. The records for many
of the species are annotated with remarks and data on
taxonomy, range, ecology, and ontogeny.

A survey of the nekton off central California to
central Baja California was begun in January
1962 by the Life History and Taxonomy Program
of the Bureau of Commercial Fisheries, California
Current Resources Laboratory, La Jolla, Calif.
The purpose of this survey was twofold : to begin
to learn what larger pelagic organisms (primarily
fishes) occur in the area sampled and to investi-
gate certain aspects of the life history of the hake
(Merlucciii.s), a species of potential commercial
importance. This report presents a list of the
more than 189 species of fishes taken on the sur-
vey, with annotations on life history, distribution,
and taxonomy for many of the species. A subse-
quent report will give data obtained on the hake
other than records of occurrence. The inverte-
brates collected were placed in the Marine Inverte-
brate Collection of Scripps Institution of Oceanog-
raphy.

Since development of the Isaacs-Kidd midwater
trawl (IKMWT) in 1950, a large number of tows
have been made in the Pacific with this type of

Note : — Approved for publication July 12, 1965.

•Present address: Tropical Atlantic Biological Laboratory,
Miami, Fla.

••Present address : Biological Laboratory, Boothbay Harbor,
Maine.

net (Aron, 1960; King and Iversen, 1962; Clarke,
1963). Specimens collected with the IKMWT
have been deposited in various museums, but only
the collections made by Aron (1960) have been
reported comprehensively. Wisner (1962) gave a
list of species and numbers of each taken in 14
IKMWT tows during Operation "Wigwam" off
Baja California.

In addition to the 10-ft. IKMWT, this survey
used a 10- by 14-ft. collapsible midwater beam
trawl (CMWBT), to be described in a later sec-
tion, a 5- by 5-ft. nekton net (Blackburn, 1960:
53-55), and the large Cobb Mark-II pelagic trawl
of about 70- by 80-ft. mouth opening (McNeely,
1963).

After examining the catches made by the var-
ious nets, it seems obvious that none of the nets
used is adequate by itself to sample the nekton of
the bathypelagic area and that a variety of nets
should be used in future surveys. The Cobb trawl,
because of its large size, is more efficient than other
nets used in catching the larger and more elusive
organisms. Direct comparisons of the catching ef-
ficiencies of these nets are not made in this re-
port, because of the many variables that entered
into the survey.

FISHERY BULLETIN: VOLUME 65, NO. 3

625

CRUISES

This report has used the collections from eight
cruises made from May 1961 through March 1963
( table 1 ) . Four cruises were made by the Bureau's
R/V Black Dougla* (B6203, B6204, B6212, and
B6303) ; two by the R/V John N. Cobb through co-
operation of the Bureau of Commercial Fisheries
Exploratory Fishing Base, Seattle, Wash.
(C6208 and C6303) ; and two cruises by the R/V
Horizon through cooperation of Scripps Insti-
tution of Oceanography (H6105 and H6204).
The cruises are briefly summarized below. The
stations at which no fish were caught are listed
below as "negative tows." The depths of tows
in meters and the number of tows (in paren-
theses) follow the information on the types of
nets used.

Cruise H6105 : R/V Horizon.; May 27-28, 1961 ;
135 to 160 km. (85 to 100 miles) west of San Diego,
Calif.; 5 tows with IKMWT: 18 (2), 178 (1),705-
1,093(2).

Cruise B6203 : R/V Black Douglas; March 2-30,
1962; San Francisco, Calif., to south-central Baja

California, up to 970 km. (600 miles) seaward; 29
tows with CMWBT and 2 tows with 5- x 5-ft. nek-
ton net : 9-132 (6), 256-264 (9), 419-423 (15), 622
(1) ; negative tows, stations 70.80a, 70.130, 80.51,
80.80, 90.150; other cruise work, oblique tows with
1-m. standard plankton nets and 2-m. stramin nets,
bottom trawls with 16-ft. otter trawls.

Cruise H6204 : R/V Horizon; March 16 to April
24, 1962; San Francisco, Calif., to Cedros Island,
Baja California, up to 970 km. (600 miles) sea-
ward; 48 tows with IKMWT: 148 (1), 298 (25),
410 (1), 1,490 (1), 1,676 (14), 1,863 (4), 2,234 (2).

Cruise B6204 : R/V Black Douglas; April 6-7,
1962; 16 to 19 km. (10 to 12 miles) SW. of San
Diego, Calif.; 6 tows with CMWBT: 38 (3), 282
(1), 564 (2) ; other cruise work, oblique tows with
1-m. standard plankton net.

Cruise C6208 : R/V John N. Cobb; August 6 to
September 7, 1962; San Francisco, Calif., to En-
senada, Baja California, up to 970 km. ( 600 miles)
seaward; 61 tows with Cobb pelagic trawl Mark
II: surface-92 (31), 183-296 (4), 366-403 (23);
negative tows, stations 90.49a, 91.39c.

Table 1. — Pelagic survey station, data
[Asterisks indicate that values are approximate]

Station

Se-

Vessel

quence

and

occu-

cruise

pied

C6208...

H6204...

C6208. . _

H6204...

C6208...

H6204...

C6208...

H6204...

('671 IS

1162111

C6208. . .

B6203. . .

H6204...

B6203. . .

H6204...

B6203. . _

H6204...

B6203...

I102O4

C6208. . .

105

C6208. . _

102

C6208. . .

103

C6208

ream

104

nviiw

106

ream

101

B6203

( IVJIIM

100

B6203

C62IIM

ream

116204 .

Location of haul

Start

Lat. N. Long. W.

End

Lat. N. Long. W.

Date

Time of tow
(P.s.t.)

Start End

Tow-

Depth of

ing

Depth

bottom

wire
out

fished

1, 189-2, 379

1, 052

•366

3,331

5,032

•1. V,3

3,111-2,928

1, 052

•366

3,843

805

•298

3,843

1,052

•366

4,117

6,039

•2, 234

4,209

1,052

•366

4,392

805

•298

4,484

1,052

•366

4,502

4,032

•1,863

4,575

1,052

•366

4,575

604

•1,419

3,697

805

•298

4,602

5,032

•1,863

5, 124

604

•423

1, SI*

805

•298

5, 124

604

•423

4,826

4, 026

•419

4,941

604

•423

4,941

•31

5,051

805

•298

110-275

4,675

183

•46

183-92

366

•92

238 677

686

201

4, 118

1,052

'366

4, 026

604

•256

4, 026

121

•29

4, 026

•9

4. UK

4,209

604

•256

4,209

4,667

1,052

•366

3,6611

604

•423

4,694

4, 529

•1.676

Type of haul

60.55

60.60

60.70

60.70 ...'.._

60.80 _

60.80

60.90

60.100-. ..

60.100

60.120

60.140

60.160

60.180

60.200a

60.200b

60.200

65.54

66.. 51 la ...

66.60b
66.100

68.50

70.61.
70.60

70.80a ..
70.80b
70.80 .Mi

70.80

70.90

70.100

70.130

37°45.5'.

37°36.6'.

37°37.0'_

37°07.9'.

37°22.2'.

36 5,4 II'.

36°55.5'.

36°34.4'_

36°36.0'_

36°n.ef_

36°15.0\

35°27.2'.

35°35.2'_

34°57.0\

34°19.0'.

34°16.0/.

33°40.5'.

33°38.0'_

32°56.8'.

32°55.0,_

37°05.0\

36 57 II'

36°58.0\

35°29.0'.

36°43.0'.

36°10.5'.

35°14.0'.

35° 13.5'.

35°13.5'.

35° 18.0'.

35°14.0'.,

31 ...i IP'

34°53.0'.

34°34.0'.

33 39 11'

31°15.0'.

123°20
123°37.
123°37
124°25
124°I2
125°04
125°04
125°46
125°38
126"31
126°32
128°00,
127°54
129° 19.
130°39.
130°41,
137 im
131°54.
133°26,
133°26.
133°28.
122°34.
122°10.
122°09,
125°51
121°58,
121°4M
123°52
123 47
123°47.
123 44
173 62
124°30.
124°33
125°15,
127°0O.
137 16

37°42.0'.

37°42.2'.
37°17.8 '.

37°03.5'.
36°38."6'~

36°12.¥'.

36°59.0'.
36°55.5'_.
36°57.0'..

36°42.0\.
36°08.0'..
35°07.5'..

123°23.8'.
i23°34.0V.

124°15.0'_

125°34.0'.

121V 25.(1'

122°32.5'.
122°07.0/.
122°07.0'.
125°52.4'_

171 5K 1 1'

i '1 i; a
123°58.5'_

35°07.5'_...

173 58.6'

. 34°47.0'.
. 34°30.0'.

124°31.0'_

125' 12.(1'

6 Aug.
26-27 Mar.

7 Aug.
27 Mar.

7 Aug.

27 Mar.
-8 Aug.

28 Mar.

8 Aug.

28 Mar.

8 Aug.

13 Mar.
28-29 Mar.

29 Mar.
13-14 Mar.
29-30 Mar.

14 Mar.
3(1 Mar

15 Mar.
15 Mar.
31 Mar.
15 Aug.
11 Aug.
11 Aug.

8-9 Aug.

13 Aug.

15 Aug.

9-10 Aug.

6 Mar.

7 Mar.
9-10 Aug.

6 Mar.

9 Aug.
9 Aug.
5 Mar.

31 Mar

1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962

Hour
1750
2024
0655
0613
1440
1250
2225
0012
0655
0809
1545
0035
2205
1022
2310
2330
1140
1300
0050
0400
0255
0044
0044
0330
2325
0841
1432
2312
1930
2300
0040
2312
1050
1520
iisni
1200
1905

Hour
2000
0005
0915
0750
1657
2000
0025
0147
0905
1226
1800
0400
0010
1511
0210
0110
1425
1650
040(1
0520
0425
0145
0144
(143(1
0125
6917
1532
0112
2300
2400
0235
0112
1455
172(1

1020

1520
2330

Oblique.

Horizontal.

Oblique.

Horizontal.

Oblique.

Horizontal.

( iblique.

Horizontal.

Oblique.

Horizontal.

Oblique.

Do.
Horizontal.

Do.
Oblique.
Horizontal.

Do.

Do.
Oblique.

Do.
Horizontal.

Do.

Do,

Do.
Oblique.

Do.
Horizontal.

Do.
Oblique.
Horizontal.
Oblique.

Do
Horizontal.

626

U.S. FISH AND WILDLIFE SERVICE

Table 1. — Pelagic survey station data — Continued

Vessel
and
cruise

Se-
quence
occu-
pied

Location of haul

Start

Lat. N. Long. W.

End

Lat. N. Long. W.

Date

Time of tow
(P.s.t.)

Start End

Depth of
bottom

Tow-
ing
wire
out

Depth
fished

Type of haul

B6203

C6208...

B6303. .

B6203..

C6208..

C6303..

116204..

B6203..

H6204..

C6208-.

C6303..

B6303..

B6203..

H6204..

C6208 .

C6303...

B6303.

B6203.

H6204.

C6208.

C6303...

B6203...

H6204...

B6203...

H6204...

B6203...

C6208...

(Y.20S .

C6208...

C1208 .

H6204___

C6208...

C6208.._

C6303...

C6303__.

B6303...

C6303...

C6303._.

C6303. . .

C6303...

B6303...

C6303...

B6303...

B6303__.

C6303...

B6203...

B6303...

B6203...

H6204...

B6203. . .

H6105.-.

H6105...

H6204...

C6208...

H6105...

C6208...

06208. .

B6203...

H6204...

C6208...

H6204...

C6208...

C6303...

C6208..

B6203...

C6303...

H6204...

C62US

H6204___

C6208. . .

B6203...

C6208..

H6204.._

25
107
163
6
112
164

113

165

166

114

167

168

115

169

116

117

118

119

120

121

122

123

108

191

183

184

185

186

188

172

170

192

191

187

182

171

189

175

162

194

181

176

173

174

110

109

111

134

133

132

180

131

178

130

129

128

30 .is ii

35°01.5'_.

34°32.0'..

34°26.5'__

34°22.3'_.

34°31.8'__

34°18.6'..

34°10.0'-.

34°06.6'._

34°09.5'..

34°11.1'..

33°59.0'._

33°49.2'__

33°54.0'__

33°48.7'_.

33°40.0'_.

33°39.0'__

33°28.7'._

33°33.0'__

33°26.0'..

33°30.0'..

33°09.0'._

33°07.0'..

33°13.1'..

32°49.0'..

32°57.0'..

32°28.3'__

32°08.7'..

31°55.0'._

31°26.0'__

31°10.0'..

30°50.0'__

30°30.0'__

30°07.0'..

29°49.0'..

29°29.0'

29o29.0'__

34°18.0'..

33°26.3'__

33°12.0'._

33°18.0'._

33°12.5'_.

33°11.5'..

33°10.7'_.

33°04.0'._

32°37.7'_.

33°12.8'._

33°12.3'__

33°06.5'_.

33°09.0'._

32°19.0'..

33°05.0'__

32°07.3'__

32°29.3'._

33°14.0'..

32°17.0'..

31°40.5'..

28°20.0'._

31°06.0'_.

31°04.6'_.

33°20.2'..

33°19.0'_.

33°21.0'__

32°45.0'._

33°00.9'__

32°55.5'__

32°49.0'. .

32°49.6'__

32°46.0'..

32°444'..

32°46.0'__

32°46.0'_.

32°21.0'_.

32°28.5'__

32°25.0'..

31°57.0'._

32°05.0'__

31°46.5'..

31*21.0'..

31°03.0'_.

30°42.5'._

30°47.0'_.

30°28.8'._

30°27.0'..

29°42.1'..,

29°42.0'._

29°25.0'._

29°24.0'._

29°03.0'_.

131°53.2'...

121°00.0'...

120°50.5'.._

120°32.8'...

120°44.0'...

120°40.2'...

120°48.0'...

121°09.7'.__

121°08.0'...

121°11.0'.._

121°10.0'-

121o30.5'_.

121°51.8'..

121°50.0'..

12!°51.0'_.

121°54.4'._

122°11.5'-.

122°32.6'._

122°35.0'._

122°30.0'._

122°38.0'..

123°14.0'..

123°15.0'._

123°16.0'._

123°55.0'..

123°56.0'._

124°36.2'.„

125°17.8'__

126°06.0'..

126°39.0'_.

127°17.5'_.

127°57.0'..

128°36.0'..

129°16.0'..

129°55.0'._

130°36.0'..

119°55.0'..

121°27.1'..

121°26.7'._

121°32.0'..

121°27.5'_.

121°25.2'..

121°30.0'..

12r5S.8'._

122°47.2'_.

121°11.0'..

121°12.0'__

121°21.5'_.

12l°28.0'..

122°52.0'_

121°12.0'..

122039.5'..

121°09.0'..

121°22.0'__

121°44.0'_.

122°03.5'._

130°22.0'...

123°12.2'_.

123°07.5'._.

118°05.3'...

118°02.7'...

118°18.3'...

118°48.6'...

119°08.3'._.

118°54.5'...

UQ'OS.O'...

119°05.7'...

119°05.4'...

119o05.1'...

119°12.0'...

119°12.0'..

119°46.8'._.

120°06.0'...

119°58.5'-_.

120°37.0'...

120M1.5'-..

12r33.0'.,.

122°01.0'..

122°32.0'._.

123°21.2'._.

123°18.8'...

124TJ6.6'...

123°59.0'...

125°16.0'-..

125°21.0'...

125°59.5'._.

125°57.0'._.

126°37.5'__.

34°59.4'...
34°30.5'...

34°18.0'-.
34°29.4'_.

34°05.8'._.
34°06.1'._.
33"53.2'...

33°42.5'...
33°44.0'...
33°34.7'...

33°21.0'.
33°22.3'.

31°50.0'...-

31°24.0'.

31°06.0'.

30°47.0'..__

30°27.0'....

30°05.0'_

29°46.0'.

29°26.0'.

34°18.0'.

33°23.8'.

33°08.5'.

33°13.5'.

33°11.5'....

33°09.0'_

33°04.8'.

32°58.0'.

32°31.4'.

33°09.5'..--

33°09.3'.

33c00.0'.

33°05.0'.

32°14.0'.

33°03.0'....

32°00.5'.

32°32.0'_

32°20.8'.
31°37.0'....

31°04.6'.
31°03.o'.

33°00.1'...
32°48.1'..,

32046.5'._
32°53.4'_.
32°51.4'__
32°49.0'..
32°44.0'..
32°44.0'..

32"22.5'.

32°03.0'.._
31°42.0'.._
31°33.2'_.
31°00.0'...

30°43.0'.

30°22.0'.

29"38.0'..__

120°59.3'.,
120°5».2'.

120°43.5'_
120°37.7'_

121o08.0'.
121°04.4'.
121°27.7'.

121°49.7'.
121°49.7\
122°29.0'.

122°29.0'.
122°38.2'.

126°07.5'.
126°40.0'.
127°18.0'.
127°55.0'.
128°38.0'.
129°19.0'.
129°54.0'.

130°34.0'.
119°53.0'.
121°24.0'.
121°26.0'.
121°27.5'.
121°25.2'.
121°20.2'.
12r25.0'.
121°55.5'.
122°49.3'_
121°08.2'.
121°09.5'.
121°19.0'.
121°26.5'.
122°48.0'.
121°07.0'.
122°41.4'.
121°04.0'.

121°45.5'.
122°04.3'.

123°07.5'.
123°02.0'.

119°05.2'.
118°44.1'.

118°57.0'.
119°n9.5'.
119°10.7'.
119°10.0'.
119°09.0'.
119°09.0'.

119°55.0'...

120"39.0'.
121°20.0'.
121°56.0'.
122°33.0'.

123°20.0'.
i24°O0."0'!

125°24.0'.
i26°62."0'".

15-16 Mar.
16 Aug.

1 Mar.

2 Mar.
20 Aug.

1 Mar.

16 Mar.
2-3 Mar.

17 Mar.
20 Aug.

4 Mar.

3 Mar.
17 Mar.
20 Aug.

4-5 Mar.

5 Mar.
3 Mar.

17 Mar.
20-21 Aug.

5 Mar.
3 Mar.

3 Mar.

18 Mar.

4 Mar.
18 Mar.

4 Mar.

4 Mar.
22 Aug.
22 Aug.

22 Aug.
22-23 Aug.

23 Aug.
23 Aug.
23 Aug.

1 Apr.
23-24 Aug.

16 Aug.
13 Mar.

8 Mar.
8 Mar.

8 Mar.
8-9 Mar.

9 Mar.

6 Mar.

5 Mar.
13 Mar.
13 Mar.

8-9 Mar.

8 Mar.

6 Mar.

9 Mar.
6 Mar.

28 Feb.

18 Mar.
8 Mar.

6-7 Mar.

16-17 Mar.

6 Mar.

22 Mar.

6-7 Apr.

22 Mar.

27-28 Mav

28Mav

6 Apr.

17 Aug.
27 May

27 May
27Mav
17 Aug.

17 Aug.
20-21 Mar.

6 Apr.

28 Aug.
5 Apr.

28 Aug.

27 Aug.

7-8 Mar.

27 Aug.

19 Mar.

7 Mar.
4 Apr.

26-27 Aug.
3-4 Apr.
26 Aug.

18 Mar.
26 Aug.

3 Apr.

1962
1962
1963
1962
1962
1963
1962
1962
1962
1962
1963
1963
1962
1962
1962
1963
1963
1962
1962
1962
1963
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1962
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1963
1962
1963
1963
1962
1962
1962
1961
1961
1962
1962
1961
1961
1961
1962
1962
1962
1962
1962
1962
1962
1962
1963
1962
1962
1963
1962
1962
1962
1962
1962
1962
1962

Hour

2310

0033

1513

1750

0227

1800

1927

2340

0100

0850

1550

2011

0830

U94S

1600

2302

0445

1405

2045

2320

0605

2030

2300

0500

0330

1512

0930

1630

0600

1110

1750

2250

0652

1135

1835

1358

2350

1951

1947

1810

1933

2058

2219

0850

0800

1400

1517

1243

2350

1310

0305

1410

1617

0645

0825

0525

2238

2035

1313

1537

0953

2320

0345

2335

0535

1605

1507

1055

1500

1845

2127
2315
0450
1220
2100
0345
2013
2050
0945
1820
0512
1045
2213
2242
1030
1715
0245
0810

Hour

0210

0133

1640

2110

0447

1955

2135

0235

0236

1100

1830

2140

0935

1424

1813

0125

0725

1635

2230

0120

0850

2200

2400

1050

0635

1654

1150

1915

0700

1245

1925

0050

0825

1315

1935

1535

0140

2051

2140

2130

2064

2215

0020

1115

1015

1700

1710

1420

0300

1530

0525

1630

1945

0845

1540

0755

0020

0100

1525

1756

1501

0215

0440

0505

1015

1735

1807

1400

1720

2100

2227
0305
0620
1400
2240
0540
2215
0025
1140
2105
0640
1600
0015
0026
1230
1945
0445
1223

4,758
348-366
503
119
458-686
77-81
695
2,196
2,196
2,196
1,501
3,294
3,660
4,260
3,660
3,569
3,660
3,660
4,209
4,392
4,026
4, 392
4, 392
4,172
3,660
3,935
4,392
4,209
4,392
4,392
4,392
4,026
4,392
4,392
4,392
4,502
4,392
458
3,660
4,026
4,026
4,026
4,026
3.660
3,843
3,843
3,294
3,477
4, 026
4,026
3,660
2,562
4,209
3,843
3,843
3,843
4,026
4,758
4,026
4,026
769-549
787
86
,391-1,684
1,510
1,720
,007-1,373
842
842
641
183-55
183-55
1,007
1,610
842-915
3,697
3,843
3,843
4,118
4,026
3,843
4,392
4,081
4, 026
4.264
4,392
4,209
4,246
4,365

M.
604
110
600
132

805

377

805

1,052

648

150

377

5, 032

1,052

377
805

640

377

6,039

377

805

377

128

1,200

1,200
1,200

805
1,200

549
686
300
80
400
600

1,464

1,144
961
824
824

1.098
700
869

1,738
650
800

1,738
64
604
800
800
800
800
190

1,812

800

1.052

1,006
251
49

604
403

1,200
800

1,200

229

1,200

600

275

4,530

800

1,200

600

4,530

•423

•13

•386

•92

•24

*27

•298

•264

•298

•366

•201

•55

•264

•1,863

•366

•264
•298

24
•183
•264

•9
•2,234
•264
•298
•264
•264

24
•403
•403

24
•298
•403

18
•165
•183
•113

18
•168
•201
•489
•366
•238
•247
•220
•311
•311
•238
•640
•274

•640

•423

•311

•320

•622

•298

1,093

•298

•366

•704

178

•423

•148

•403

•298

•403

•82

•403

•423

•92

•1,676

•298

•403

423

•1,676

Do.
Do.

Oblique.

Do.
Horizontal.

Do.

Do.
Oblique.
Horizontal.
Oblique.
Horizontal.
Oblique.

Do.
Horizontal.
Oblique.
Horizontal.
Oblique.

Do.
Horizontal.

Do.

Do.
Oblique.
Horizontal.

Do.
Oblique.
Horizontal.
Oblique.

Do.
Horizontal.
Oblique.

Do.
Horizontal.

Do.
Oblique.
Horizontal.

Do.

Do.
Oblique.
Horizontal.

Do.
Oblique.

Do.
Horizontal.

Do.
Oblique.

Do.
Horizontal.

Do.
Oblique.

Do.
Horizontal.
Oblique.
Horizontal.

Do.

Do.
Oblique.
Horizontal.

Do.

Do.
Oblique.
Horizontal.
Oblique.
Horizontal.

Do.
Oblique.
Horizontal.

Do.

Do.
Oblique.
Horizontal.

Do.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

627

Table 1. — Pelagic survey station data — Continued

Se-

Vessel

quence

and

occu-

cruise

pied

C6208...

127

B6203...

H6204...

C6208...

126

C6208...

125

H6204...

C6208...

124

C6208...

146

C6208. .

147

C6208...

148

C6208...

150

B6303...

177

C6208. . .

141

C6208...

142

C6208. . .

140

C6303...

190

C6303...

179

C6208...

139

C6208...

143

C6208...

135

C6208...

136

C6208...

137

C6208. .

149

C6208...

151

C6208...

144

B6204...

C6208...

145

B6204...

C6303...

197

B6203...

C6303...

195

C6208...

138

H6204...

C6303...

198

H6204...

C6303...

196

H6204...

C6303...

199

C6303...

200

C6303...

201

H6204...

C6303...

203

C6303...

204

H6204...

C6303...

202

B6203...

H6204...

H6204__.

H6204...

C6303...

207

C6303...

208

C6303...

205

C6303...

206

C6303...

209

C6303. ._

210

B6212...

152

H6204...

B6212...

153

H6204...

II6204...

B6212...

154

B6203...

B6212...

155

B6212...

156

B6212...

157

B6212...

158

B6203...

B6212...

159

B6212...

160

B6212...

161

Location of haul

Start

Lat. N. Long. W.

End

Lat. N. Long. W.

Date

Time of tow
(P.s.t.)

Start

End

Depth of
bottom

Tow-
ing
wire
out

Depth
fished

Type of haul

29°05.0'..

28°25.0'_.

28°22.0'..

28°26.0'..

28°06.5'_.

27°46.0'_.

32°53.3'_.

32°52.9'..

32°51.7'..

32°59.5'..

30°18.8'_.

33°03.5'..

32°58.5'_.

32°53.5'_.

32°51.1'..

30°31.2'_.

32°49.5'..

32°50.5'_.

32°47.0'..

32°44.0'_.

32°46.5'_.

32°43.5'..

32°47.0'_.

32°39.C

32"33.0'..

32°35.4'_.

32°37.0'_.

32°29.0'.

32°29.0'..

32°31.4'_.

32°30.7'_.

3r49.0'_.

31°35.0'..

3r00.0\.

31°54.4'..

31°21.2'..

31°21.0'..

31°00.0'_.

30°39.0'..

30°32.5'..

29°58.5'__

29°38.0'__

29°19.0'._

28°40.5'._

27°59.4'..

27°22.6'..

30°18.4'..

29°30.0'..

29°12.1'..

29°46.5'..

29°46.3'__

29°41.2'__

29°32.4'__

29°28.4'._

29°16.5'_.

27°32.1'_.

26°56.8'..

26°16.0'..

25°34.7'..

29°41.5'..

29°39.1'..

29°34.7'..

29°38.9'..

29°13.0'..

29°21.0'..

28°11.0'._

27°43.2'..

27°44.0'..

27°29.1'..

27"00.0'..

26°51.0'..

26°31.0'..

26°09.0'..

27°08.0'..

2fi°58 I)'

26°32.8'_.

26°12.0'_.

25°45.5'_.

25°O6.0'..

24°40.0'_.

24°35.5'_.

24°11.0'_.

23°42.0'_.

126°38
127=58
128°00.
127°57.
128°33
129°14.
129°14.
118°23
118°24.
118°22.
117°24
123°27
117°19.
117°23
117°25
117°35
122°15
117°20
1I7°20
117°19
117°18
117°18
117°17
117°19
117°24.
117°27.
117°30.
117°23
117°21.
117°21.
117°21.
117°23
117°53
118°30.
119°32
116°59.
117°26.
117°27
118°09.
118°45.
119°09.
120°07
120°46
121 °25
122'46.
124°05
125°20
117°47
118°00
118"09
115°58
116°01
116°41
116°15
116°47
116°59
120°14
121 °32
122°49
124°07
115°59
116°01
116°00
116°01
115°30
115°38
115°41.
115°32.
115°33
115°51.
116°36.
117° 09.
117°47.
118°26.
115°11,
115°31
114°54,
114°14
113°27
112°56
114°02
112°42
112°03
1U°44

0'...
V...
0'...

29°03.0'...

126°42.0'_.

28°23.0'.
28"03.5'.

128°00.0'.
128°40.0\

27°43.0'.
32°32.8'.
32°51.8'.
32°51.5'.
33°03.0'.
30°12.O'.
33°01.5'.
33°00.5'.
32°53.5'_
32°49.2'_,
30°26.2'.
32°47.5'.
32°48.0'_.
32°45.5'_
32°46.0'_
32°45.0'..
32°42.0'..
.32°44.0'..
32°38.0'.,
32"35.4'_.
32°38.6'..
32°35.0'..
32°30.6'..
32°30.7'..
32°30.7'..
32°32.2'_.
31°45.2'..

129°16.0'.

118°22.0/.
118°22.0'.
117°24.5'_.
123°24.0'„
117°18.0/..
117°24.0'.
117°27.0'.
117°32.3'.
122°09.8'.
117°20.5'.
117°19.5'_.
WT19.V..
117'18.S'..
117°19.7'.,
117°17.5'.
117°18.0'..
117°23.5'.,
117°30.8'.
117°33.3'..
117°21.5'..
117°23.1'_.
117°24.5'..
117°24.5'..
117°25.5'..
117°46.7'..

30°54.7'.
31°51.5'.

119°28.4'.
116°57.5'.

31°18.0'..

117°27.3'_.

119°06.2'...

30'05.5°.
29°21.0'.
29°13.8'.

117"45.2'_
118°00.0'.
118°03.5'.

29°42. 8'.
29°36.2'_

115°69.0'.
115°59.0'.

29°34.7'.
29°32.4'.
29°32.0'.
29°31.0'.
29°10.8'.
29°14.5'.
28°08.0'.

115°57.5'.
116°00.6'.
115°59.0'.
116°00.4'.
115°28.5'.
115°32.4\
115°40.5'.

27°38.7'_...

115°30.2'.

27°01.2'.

1.V09.4'.

26°27.5'.
26°07.0'.
25°41.5'_
25°01.0'.

114°50.7'.
114°14.0'.
113°31.0'.
112° 56.0'.

24°29.0'.
24°08.0'.
23°39.5'.

112°42.0'.
112°02.3'.
111°36.0'.

25 Aug.

962

18 Mar.

.962

2 Apr.

962

25 Aug.

962

24-25 Aug.

962

2 Apr.

962

24 Aug.

962

5 Sept.

.962

6 Sept.

962

6 Sept.

962

6 Sept.

962

7 Mar.

'It'ut

3 Sept.

962

3-4 Sept.

962

3 Sept.

962

12 Mar.

963

7 Mar.

963

2 Sept.

962

4 Sept.

962

31 Aug.

962

1 Sept.

962

1 Sept.

962

6 Sept.

962

7 Sept.

962

4 Sept.

962

7 Apr.

962

7 Apr.

062

4 Sept.

962

6 Apr.

962

6-7 Apr.

962

7 Apr.

962

7 Apr.

962

21 Mar.

963

27 Mar.

962

19 Mar.

963

1-2 Aug.

962

12 Apr.

962

22 Mar.

963

12 Apr.

962

12-13 A Dr.

962

19 Mar.

963

13 Apr.

962

14 Apr.

962

14 Apr.

962

14 Apr.

962

15 Apr.

962

6 Apr.

'.«;■_■

22 Mar.

963

22-23 Mar.

963

23 Mar.

963

21 Apr.

962

23 Mar.

963

24 Mar.

963

20 Apr.

962

23 Mar.

963

28 Mar.

962

19 Apr.

962

18 Apr.

962

18 Apr.

962

17 Apr.

962

26 Mar.

963

26 Mar.

963

25 Mar.

963

25 Mar.

963

26 Mar.

in;)

27 Mar.

963

1 Dec.

962

22 Apr.

962

1 Dec.

962

22-23 Apr.

962

23 Apr.

962

23 Apr.

962

24 Apr.

962

24 Apr.

962

1-2 Dec.

962

28-29 Mar.

962

2 Dec.

962

2 Dec.

'.".J

2 Dec.

962

3 Dec.

962

29-30 Mar.

962

3 Dec.

962

3 Dec.

962

3 Dec.

962

Hour
1930
0020
1900
0600
2225
0534
1525
2037
0015
1005
2256
0030
2017
2315
0840
1305
1215
0115
0230
1142
0745
1913
1715
0142
2025
0218
0400
2025
1320
2305
0043
1434
1822
0140
0858
2245
0229
0450
1020
2120
1530
1630
0O48
0941
2230
1008
0306
1300
2230
0328
0200
2100
1225
2120
1412
0100
0520
1644
0653
1530
0200
0900
0912
1425
1700
1040
1257
1634
1724
2305
0850
1640
0044
0715
2312
2325
0520
1219
1952
0309
2152
0803
1457
1925

Hour
2110
0200
2040
0740
0025
1006
1705
2120
0134
1030
2356
0255
2130
0015
1215
1510
1450
0215
0400
1310
0943
2022
1820

2131
0350
0545
2131
1422
0025
0207
1625
2115
0415
1245
0020
0414
0620

0205
1930
2100
0305
1347

1416
0724
1830
0200
0620
0400
2315
1624
2300
1600
033a
0700
2057
0750
1930
0550
1330
1255
1900
1840
1435
1434
1813
1922
0328
1023
2042
0223
1135
0137
0225
0752
1433
2148
0510
0034
1032
1612
2150

M.
4.301
4,026
4,484
4, 392
4,392
4,209
4,392
732
366

458
4,026
37-55

549

732

4,026

366

73-146

275
92
92

275
549-641

961

137

686-1098

421^39

2,196

3,477

732
1,874
1,995
1,739
2,782
3,111
3,962
3,861
3,843
4,099
4,209
4, 145
2,837
3,569
1,830
1,153
1,153
1,830
2,416
1,830
3,660
3,953
4,269
4,108
4,200
1,830
2,196
2,196
2,196

220

549

586
3,294
2,196
3,916
3,660
3.660
3,861
4,063
4,118
3,660
3,203
2,745

366
1,281
3,660

732
176-183

275

1,200
600
800

1,200

4,530
1,200

915
916
549

400
800
92
800
732
600
1,372

800

4. 530

1, 372

4,530

800

4,530

800

4,530

824

1,372

800

732

1,190

800

640

600

800

4,530

1,100

4,530

686

1,372

1,372
640
686
657
800
600

4,530
800

4.530
150
600
600
800
500
400
600
800
390
400

•403

•423

•298

•403

1,676

•403

Surface

•73

Surface

201

•274

•105

Surface

296

•9

•82

Surface

183

'37

•37

Surface

•282

•563

•37

•563

•274

•423

•458

•298

•1,676

•458

•1,676

•298

•1,676

•298

•1,676

220

•458

•298

•201

•403

•298

•156

•423

•298

•1.676

•410

•1,676

•165

Oblique.
Horizontal.

Do.
Oblique.
Horizontal.

Do.

Do.
Oblique.
Horizontal.

Do.

•366
•403
150
•192
•306
•298
•311

M.676
•298

•1,676
•298

•1,676
•55
•423
•320
•412
•240
•176
•423
•426
•152
•176

Oblique.

Do.
Horizontal.
Oblique.
Horizontal.

Do.

Do.
Oblique.

Do.

Do.
Horizontal.
Oblique.

Do.

628

U.S. FISH AND WILDLIFE SERVICE

Cruise B6212 : R/V Black Douglas; December
1-3, 1962; central to southern Baja California, to
about 80 km. (50 miles) seaward; 10 tows with
CMWBT: 55-176 (4), 240-311 (3), 386-426 (3);
other work, collections at Marquis Point and Mag-
dalena and Santa Maria Bays, Baja California,
using seines, rotenone, otter trawls, and dip nets.

Cruise B6303 : R/V Black Douglas; February
28 to March 18, 1963 ; Point Conception to off San
Diego, Calif., to about 480 km. (300 miles) sea-
ward; 13 tows with CMWBT: 18-73 (3), 113-201
(3), 274-386 (5), unknown (2) ; negative tows,
stations 87.70a, 87.70b; other work, oblique and
horizontal tows with 1-m. standard plankton net

and 1-m. closing net and bottom trawling with
16-ft. otter trawl.

Cruise C6303 : R/V John N. Cobb; March 1-27,
1963; Point Conception, Calif, to central Baja
California, to about 430 km. (270 miles) seaward;
36 tows with Cobb pelagic trawl Mark II : 9-27
(5), 82-192 (10), 201-403 (15), 458-489 (4), 640
(2) ; negative tows, stations 80.70, 85.68, 111.36b.

STATION DATA

The basic station numbering system in use since
1950 for the California Cooperative Oceanic
Fisheries Investigations (CalCOFI) was used for
station designation during the pelagic survey (fig.
1 ) . An explanation of this numbering plan was

n — r

t — i — i — r

l i i r

- — i — r

CALCOFI
BASIC STATION PLAN

SINCE 1950

Svrm.

• »*• * ■ • j» ■ -= ••% ?.• \,

J L

J I I L

J L

J I L

J L

J I L

J L_J L

Figure 1. — CalCOFI basic station plan since 1950.
PELAGIC FISHES, CALIFORNIA CURRENT AREA

6or

given by Scripps Institution of Oceanography
and Fish and Wildlife Service (1952). The sta-
tions occupied during the eight cruises are shown
in figures 2A and 2B.

The station data for the cruises are given in
table 1. An asterisk in the table indicates an ap-
proximate value. The stations are listed in in-
creasing numerical order by line from north to
south and by station number from east to west.
When the same station was occupied more than
once during a cruise, the earliest occupancy was
designated "a", the next "b", . . . The depth
fished was determined or estimated in a variety of
ways. A depth telemeter with a conducting cable
was used for some stations on cruise C6208; the
Brown Depth Recorder for several stations on
cruises H6105 and H6204; and a bathykymograph
for a few stations on cruises B6203, B6204, B6212,
and B6303. For some stations on cruise H6204,
a factor of 0.37 times the length of the wire out,
was used to estimate the depth fished.

The depth of bottom at each station, the amount
of wire out, and the depth fished are recorded in
meters. This has produced some, uneven or ir-

regular numbers that are frequently repeated in
table 1. One reason for this is that depth of bot-
tom at each station was originally recorded in
fathoms, either from the depth recorder or chart
reading, and was subsequently converted to meters
to conform to the required style of this report. At
a number of stations on some of the cruises, the
amount of wire out was set at a particular number
of meters, and the calculated or estimated fishing
depth was a reflection of amount of wire out (for
example, on cruise H6204 most stations were made
with either 800 or 4,500 m. of wire out, and the
estimated depth of fishing was 298 and 1,676 m.,
respectively).

The types of tows are listed as horizontal or
oblique. For horizontal tows, a selected amount
of wire was let out and the trawl was towed within
a generally restricted dearth range. Obviously,
the trawl was fishing in descent to and ascent from
this depth, but most of the fishing effort for a
horizontal tow was usually near the maximum
depth fished. It is recognized that after the
selected amount of wire has been let out, the trawl
may sink for a time while being towed. Also, if

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133 M
137 90

140 39 J
143 3tf^
14730

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I'm, i be 2. — (A) Stations occupied during pelagic survey, (B) Stations occupied in the central and shoreward portion

of the pelagic survey .

630

U.S. FISH AND WILDLIFE SERVICE

the ship's speed is reduced when the wire retrieval
begins, the trawl may sink and continue fishing
deeper than the calculated maximum depth re-
corded for the horizontal tow. The oblique tows
were made in two ways: (1) by letting out a
selected length of wire as fast as feasible and re-
trieving slowly or in stages (as, on a deep tow,
taking in 100 m. of wire during about 3 to 5 min-
utes and towing for 10 minutes before retrieving
more wire) and (2) by letting the wire out slowly
or in stages and retrieving as fast as possible.

COLLAPSIBLE MIDWATER BEAM TRAWL

On vessels such as the Black Douglas, inade-
quately equipped to operate (most) large nets, it
was necessary to have a collapsible net (fig. 3).
Views of operation of the net and certain details
of construction and the jury-rigged winch and H-
frame aboard the Bl-ack Douglas are shown in
figures 4 and 5.

In devising the CMWBT, several features desir-
able in operating such a net were considered, and
attempts were made to incorporate these features
into the design and function.

Mouth opening. — This should be large to sample
a relatively large area and to reduce escapement.

The horizontal opening was fixed at 10 feet by the
top and bottom beams. The vertical, nonrigid
opening was hung at 14 feet. In towing, the
vertical opening was reduced to about 12 feet at 2
knots and to about 10 feet at 4 knots; the latter
still left a sampling area of about 100 square feet.

Towing speed. — The CMWBT was strongly
constructed. The maximum speed at which it
was towed was about 5 knots, but faster speeds
could have been used.

Mouth opening obstruction. — There was no ob-
struction from the top beam bridle, and that from
the bottom beam bridle was not great ; this could
be eliminated by a spreader bar.

Specimen damage. — This was reduced by a
specially constructed cod end (figs. 3 and 5D).

The bullet-shaped device attached to the top
beam in figure 4 is a bathykymograph. This
model functioned sporadically and unsatisfactor-
ily in our experiments.

SUMMARY OF FISHES COLLECTED

More than 189 species of fishes were taken in the
survey. The exact number cannot be determined
at. this time because of the uncertain identifica-
tion of more than 18 forms. At least one previous-

.-—TOWING LINE CLAMP

\\ .-TOP BRIDLES
\\/ 12' 3" LENGTH

\ \ 1*

10'

BEAU

\ \ ^ TOP BEAM

\s"

4' 3" LENGTH

BOTTOM BRIDLES'1
25' 9" LENGTH

- BOTTOM BEAM
-DEPRESSORS

-TWO IRON RINGS
-METER 0IAMETER

CANVAS COD END
WITH 1/8" ACE
NYLON LINER

. 2" BAR NYLON WITH
1/8" BAR ACE NYLON LINER

Figure 3. — Diagram (lateral view) of 10- by 14-ft. collapsible mid water beam trawl (CMWBT).
PELAGIC FISHES, CALIFORNIA CURRENT AREA

631

Figure 4. — CMWBT. A, emerging. B, boarding. C, top beam secured to H-frame. bauling in bottom
beam. D, both beams secured. Cylinder attached to middle of top beam is bathykymograph.

ly unnamed and undescribed genus and at least
four undescribed species were taken; these speci-
mens have been made available to specialists work-
ing on the groups concerned. Sixteen orders of
fish and 71 families are represented, including 52
species of the order Isospondyli, 51 species of
Iniomi, and 37 of Percomorphi. The greatest
number of species in a single family was 40 in the
Myctophidae. The greatest number of species in
a single genus was 12 in Lampanyctu*- (Mycto-
phidae) ; the next greatest was 8 in Melam phurx
(Melamphaidae).

About 52,000 fish were taken in the pelagic sur-
vey. The order Isospondyli comprised about 56
percent of this total, including the numerically
most abundant species, Engraulis mordax, which
itself was 34' percent of the total number. The
Iniomi was the second most abundant order, about
38 percent of the total; the family Myctophidae
comprised most of this percentage. The mycto-
phid genus Lampanyctws (including the subgenus
Triphoturus) , was 21 percent of the total, and
Lampanyctus (Triphoturus) mexlcanus was the
second most abundant species — about 18 percent

632

U.S. FISH AND WILDLIFE SERVICE

Figure 5. — CMWBT. A, towing; note H-frame, slush block, angle indicator, meter wheel, winch, and
capstan. B, depressor and rib on back of bottom beam for lashing net. C, afterpart of net with two
detachable one-meter rings. D, lined cod end and cod-end clamp.

of the total. Forty-four of the species were rep-
resented by a single specimen. The preponder-
ance of anchovies (Engraulismordax) in the above
figures does not indicate a high relative abundance
of this species over the survey area — as is true for
Lampanyctus (T.) mexicanus — because the bulk
of the anchovies taken on the survey was from two
large catches at stations close to shore.

During the survey, 198 tows caught one or more
fish (12 other tows did not catch fish, for various
reasons). Species of Myctophidae were taken at

more of the "successful stations" than any other
family. Lampanyctus (T.) mearicanus was taken
at 76 stations — more than any other species. Other
myctophids caught at a relatively large number
of stations were : Heirops crockeri and Ceratosco-
pelus tovmsendi (66 stations each), Lampanyctus
ritteri (63 stations), Diaphm iheta (61) , Symbolo-
■phorus calif orniense (55), and Stenabrachius leu-
copsarus (54). Of the Gonostomatidae, Cyclo-
thone signata was taken at 64 stations, Cyclothone
acclimdens at 49, and Danaphvs oculatus at 47.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

633

Three species of Sternoptychidae were captured
at a large number of stations — Argyropelecus
hawaiensM at 54, A. pam'ficus at 49, and A. inter-
medius at 45. Three other species collected at a
number of stations were Idiacanthus antrostorrmx
and Scopelogadus mizoleph bispinosus (50 each)
and Merluccms productus (42). Sixty of the
species recorded were caught at only one station.

The most abundant species in a single tow was
Engraviis mordax — about 9,000 specimens (450
pounds) taken at a single station. Larripanyctus
(T.) mzxieanus had the next highest numbers —
about 3,000 specimens at one station and 1,857 at
another. Other large single collections were
Ceratoscopelus townsendi (944), Stenobrachius
leucopsarus (735), Vinciguerria lucetia (537),
Merluccius productus (495), and Leuroglossus
stilbius (396).

The maximum number of species in a single tow
was 44, with the Cobb pelagic trawl on cruise
C6303 at station 86.92. On the same cruise, re-
latively large numbers of species per tow were
taken at stations 100.65 (41 species), 83.77 (38),
and 87.80 (37). Maximum numbers of species per
tow with the 10-ft. Isaacs-Kidd midwater trawl
(IKMWT) were taken on cruise H6204 at stations
80.90 (34 species) and 60.60 (32) . The maximum
number of species per tow with the collapsible net
was 21 on cruise B6303 at station 84.92.

Many variables affected the numbers and spe-
cies of fishes caught on the survey including depth
of tow, time of year, diurnal migration, speed and
length of tow, size of net, size of net webbing, and
water mass sampled. Because of these variables,
many of the numbers and percentages just cited
relate to the survey rather than to the character of
the pelagic environment.

For abundant and for more significant species,
the locations of capture are shown on distribution
charts. These charts bear one symbol for each sta-
tion at which a species was caught — they do not
indicate the capture of a species more than once at a
single station.

The specimens preserved from the pelagic survey
have been placed in four collections. Some of the
larval and juvenile forms are in the Bureau of
Commercial Fisheries California Current Re-
sources Laboratory. A small representative series
of the bathypelagic species is in the Stanford Uni-

versity Natural History Museum. A large repre-
sentative series of most species taken is in the Fish
Division of the U.S. National Museum. The re-
mainder of the material, comprising the bulk of the
collection and representatives of most species
taken, is in the Marine Vertebrate Collection of
Scripps Institution of Oceanography. The dis-
position of all the specimens is recorded in the Field
Data Books of the Bureau Laboratory at La Jolla
and in the collection records at Scripps Institution
of Oceanography. Representative type material
of any new taxa that are based on these specimens
will be placed in the U.S. National Museum.

ANNOTATED LIST OF FISHES

In preparing the data for this report we at-
tempted, with the help of other ichthyologists, to
determine specific identifications of the specimens.
Many taxonomic problems were not solved; we
briefly describe these in the annotations of the spe-
cies and also include our resolutions of some of the
problems.

The fishes listed below are arranged phylogene-
tically by order and family. Each record of cap-
ture is listed under the species in the following ab-
breviated form, from left to right: the station of
capture; the cruise during which the station was
occupied; the number of specimens taken at that
station, in parentheses; and the length or length
range in millimeters of the specimens. For some
collections, numbers or lengths of specimens are not-
available; for others, weight instead of length is
given. At a few stations specimens were discarded
at sea before accurate records were made.

Lengths of specimens are given in millimeters of
standard length (SL), except where otherwise
noted. Total length (TL) is used for a few species,
and where this designation is given for the initial
entry in a species list, all subsequent measurements
in that list are in total length. Specimens 100 mm.
in length and larger were measured to the nearest
millimeter; most specimens smaller than 100 mm.
were measured either to the nearest millimeter, or
to the nearest half-millimeter. In collections with
damaged specimens that were not measured, "dis."
(disintegrated) is used instead of a length. A plus
sign following the length measurement of some
specimens indicates that a portion of the posterior
end of the body was missing.

634

U.S. FISH AND WILDLIFE SERVICE

ELASMOBRANCHII
CARCHARHINIDAE

1. Prlonace glauca (Linnaeus).

Figure 6A.
60.55. C6208, (4) 865-1.785 mm. TL : 65.54, C6208, (3)
1,255-1.365 mm.; 91.39b, C6208, (1) 568 mm.; 107.60,
C6303, (1) 1,200 mm.

MYLIOBATIDAE

2. Holorhinus califormcus (Gill).

Figure 6A.
93.26, C6208, (3) ea. 5 kg., no length recorded.

TORPEDINIDAE

3. Torpedo californica Ayres.

Figure 6A.

77.51, C6208, (1) 453 mm. TL; 80.52, C6208, (1) 422
mm. ; 94.28b, C6208, ( 1 ) ca. 5 kg. ; no length recorded.

This species is generally considered to be a ben-
thic inhabitant of moderately deep water. For
the first two records above, however, night tows of
the Cobb pelagic trawl at the surface (trawl fish-
ing no deeper than 24 m.) captured single speci-
mens of Torpedo about 24 km. (15 miles) offshore
in water about 350 to 690 m. deep.

ISOSPONDYLI
CLUPEIDAE

4. Sardinops caerulea (Girard).

Figure 6B.
94.28b, C6208, (9) 225-275 mm.; 94.29b, C6208, (43)
195-235 mm.; S4.29c, C6208, (2) 195 mm.; 94.30, C6208,
(1) 225 mm.

ENGRAULIDAE

■5. Engrmdis mordax Girard.

Figures 6B and 7.

65.54, C6208, (ca. 450) 113-150 mm. ; 66.50, C6208, (few)
ca. 102 mm.; 70.60, C6208, (1) 33 mm.; 70.80, C6208, (2)
29-30 mm.; 70.90, C6208, (17) 21-27 mm.; 77.51, C6208,
(ca. 250) 102-143 mm.; 80.52, C6208, (10) 28.5-143 mm.;
80.60, C6208, (1) 37 mm. ; 80.65, B6303, (1) 121 mm. ; 80.80,
H6204, (1) 141 mm.; 82.45, C6208, "10 lbs. (4 kg.) in all,"
sample (19) 109-150 mm. ; 82.69, C6303, (58) 118-144 mm. ;
83.70b, B6303, (25) 120-140 mm.; 83.70c, B6303, (1) 131
mm.; 84.70, C6303. (44) 120-137 mm.; 87.90 C6303, (1)
150 mm.; 90.32, H6204, (3) 108-123 mm.; 90.45, H6105,
(13) 4-14 mm.; 90.48b, H6105, (193) 4-28 mm.; 92.28,
C6208, (50) ca. 125 mm.; 93.28, C6208, (ca. 100) 2 kg.
adults; 93.29, C6208, (200 kg.) 100 fish sample, 85-135
mm.; 94.29b, C6208, (4) ca. 100 mm.; 94.29c, O6208, (16)
55-125 mm. ; 95.30, C6208, (1) 150 mm. ; 97.40, C6303, (1)
121 mm. ; 99.31, C6208, (16) ea. 50 mm. ; 107.60, C6303, (2)
123-126 mm.; 110.35. C6303, (6) 116-126 mm.; 113.34b,
C6303, (ea. 170 kg.) 115-135 mm.; 120.45, H6204, (2)
16-17.5 mm.; 120.50, H6204, (2) 12.5-14 mm.

Anchovies were taken at 33 stations. Nine of
these records were of larvae or small juveniles from
close inshore to about 260 km. (160 miles) off-
shore. Three stations produced records of an-
chovies that add significantly to our knowledge of
the biology of this species. (1) At station 89.90,
C6303, one adult was taken about 400 km. (250
miles) from nearest landfall. (2) At station
83.70, B6303, in the San Juan Seamount area —
where hake eggs were abundant in routine
oblique plankton tows (to about 140 m.), and
where freshly spent hake were caught in about 121
and 165 m. — anchovy eggs were abundant in a
near-surface plankton tow (about 5.5 m.), and
running ripe anchovies were caught in a midwater
trawl at about 81 m. The Cobb echo sounder
showed subsurface concentrations at 73 m. and 146
to 220 m. in this area. These concentrations prob-
ably represented anchovies spawning above a
deeper school of hake that was spawning or had
just finished spawning. (3) At station 93.29,
C6208, 13 km. (8 miles) off La Jolla over water
about 475 m. (260 fathoms) deep, the Cobb Simrad
registered a dense concentration at about 201 m.
(110 fathoms) (fig. 7) . With the aid of the depth
telemeter, the trawl was towed through this area.
The resulting catch was 200 kg. of anchovies. The
Simrad was monitored throughout the tow; and
the lack of other concentrations indicated that a
dense and unusually deep school of anchovies was
sampled. A bathythermograph (BT) cast at this
station showed a surface temperature of 68° F., a
thermocline at about 18 to 82 m., and a temperature
of 74° F. at 201m.

ALEPOCEPHALIDAE

6. Alepocephalus tenebrosus Gilbert ?

Figure 6C.

80.90, H6204, (1) 12.5 mm.; 100.60, H6204, (1) 25 mm.;
100.80, H6204, ( 1 ) 28 mm. ; badly damaged. .

The specific identifications are questionable be-
cause of the small size of the specimens.

7. Tallsmania bifwrcata (Parr).

Figure 6C.

90.120, H6204, (1) 33 mm. ; 110.120, H6204, (1) 47 mm. ;
120.50, H6204, (1) 44 mm.

SEARSIDAE

8. Sagamichthys abei Parr.

Figure 6C.

60.60, H6204, (2) 25.5-41.5 mm.; 60.80, H6204, (1) 45.5
mm.; 60.80, C6208, (2) 106-139 mm.; 60.90, H6204, (1)

PELAGIC FISHES, CALIFORNIA CURRENT AREA

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Figure 6. — Locations of capture of: A, Prionace glauca, ffolorliinux californicux. Torpedo californica. B,
Sardinops earn/lea, Engraulis mordax. C, AJepocephalua tenehrosust, Talismtmia bif areata. Saga-
michthys abei. D, Pellisolus faeilis, Mirorietu.i taaningi, lloltbyrnia maeropst, lloltbyrnia sp.

636

U.S. FISH AND WILDLIFE SERVICE

40N!

Figure 7. — Simrad tracing of a concentration 110 fathoms deep, presumed to be a school of Engraulis
mordax. The recording, from left to right, is nearly continuous — the two vertical white lines were
caused by brief intervals when the machine was not inking the paper. The vertical black line on
the left is the reference mark indicating start of the tow at depth. John N. Cobb station 93.29,
cruise C6208.

77 mm.; 60.100, H6204, (1) 24.5 mm.; 80.55, H6204, (1)
63 mm. ; 80.70, H6204, (1) 21 mm. ; 83.77, C6303, (4) 53.5-
116 mm. ; 86.92, C6303, (3) 106-215 mm. ; 87.80, C6303, (3)
96-147 mm. ; 90.48a, H6105, (5) 26-28.5 mm. ; 90.70, H6204,
(1) 38.5 mm.; 90.70, C6208, (2) 164-171 mm.; 95.31c,
B6204, (4) 18-36.5 mm. ; 97.50, B6203, (1) 35.5 mm. ; 97.65,
C6303, (8) 43-223 mm. ; 100.40, H6204, (1) 37 mm. ; 100.60,
H6204, (1) 118 mm.; 100.65, C6303, (28) 63-252 mm.;
100.90, H6204, (1) 90 mm.; 100.100, H6204, (1) 121 mm.;
108.63. C6303. (52) 128-245 mm.; 120.80, H6204, (1) 58.5
mm. ; 140.35, B6212, ( 1 ) ca. 18 mm.

These specimens differ in certain respects from
the original description of the holotype by Parr
(1960 : 42), but further study is necessary to eval-
uate these differences (R. J. Lavenberg, personal
communciation). The Cobb Mark-II pelagic
trawl took this species in relatively large numbers
(52 in one tow and 28 in another) and at larger
sizes (up to 252 mm.) than were previously re-
corded.

9. PeUisolus facilis Parr.

Figure 6D.
90.120, H6204 (1) 56.5 mm.

This specimen represents an appreciable range
extension from the type locality south of Panama
given by Parr (1960 : 97) .

10. Mirorhctus taaningi Parr.

Figure 6D.
120.70, H6204, (1) 120 mm.

The jaw morphology and mechanism in this and
another specimen examined are like that of all
other alepocephalids and most other fishes and not
like that described for the apparently distorted
holotype by Parr (1960: 30). This fish and a
specimen in the collection of Scripps Institution of
Oceanography from near Guadalupe Island ex-
tend the recorded range of the species from the
type locality in the Gulf of Panama.

11. Holtby7Tiia. macrops Maul ?

Figure 6D.

80.90, H6204, (2) 23-64 mm.; 100.140, H6204, (1) 33
mm.

These specimens are questionably identified, be-
cause slight differences suggest that they may be
specifically distinct from the species described
from off Madeira by Maul (1957: 11) (R. J.
Lavenberg, personal communication). This
species was placed in a new subgenus, Krefftia, by
Parr (1960:71).

PELAGIC FISHES, CALIFORNIA CURRENT AREA

637

12. Holtbyrnia sp.

Figure 6D.

80.100, H6204, (1) 22.5 mm.; 90.45a, H6105, (2) 28-29.5
mm.; 90.-L8a. H6105, (9) 15-33.5 mm.; 120.90, H6204, (1)
31.5 mm.

These specimens are specifically distinct from
those listed above as Holtbyrnia mazrops Maid ?
and may represent an undescribed species (R. J.
Lavenberg, personal communication).

ARGENTINIDAE

13. Nameniasp.
90.120, H6204, (1) 10.5 mm.

This specimen was taken about 500 km., south-
east of Point Conception, Calif. There appear to
be two species of Namenia in the eastern North
Pacific — a more northern form described as N.
Candida by Cohen (1958: 53) and a more south-
ern form which is apparently undescribed. The
above specimen, because of its small size and the
intermediate location of its capture between the
known ranges of the two species, cannot now be
specifically identified (E. H. Ahlstrom, personal
communication). The familial classification of
this and the six following genera of argentinoid
fishes was proposed by D. M. Cohen (personal •com-
munication).

14. Argentina sialis Gilbert.
95.31b, B6204, (1) 22.5 mm.

This specimen was taken about 25 km. ( 15 miles)
west of San Diego, ( Jalif.

15. Microstoma microstoma (Risso).
83.90, C6303, (1) 115 mm.

This specimen was taken about 275 km. (170
miles) southeast of Point Conception, Calif.

BATHYLAGIDAE

16. Leitrogloxsux xtill>'nt.s Gilbert.

Figure 8A.
70.80-5N, B6203. (1) 31 mm.; 77.51, C6208, (1) 89 mm.;
80.55, H6204, (5) 33.5-107 mm.; 80.60, H6204, (1) 46mm.;
80.70, H6204, (1) 32 mm.; 80.90-5N, B6203, (4) 28.5-32
mm.; 80.90, H6204. (3) 30.5-69 mm.; 82.45, C6208, (123)
47-!>4 mm.; 82.69, C6303, (39) 28-109 mm.; 83.70c, B6303,
(2) 61.5-74 mm.; 83.70, C6303, (3) 78-90 mm.; 84.70,
('6303, (28) 61-110 mm.; 90.32, H6204, (52) 32-99 nun.:
90.45a, H0105, (99) 22-106 mm.; 90.48a, H6105, (339)
5.5-51 mm. ; 90.48b, H6105, (396) 5-23 nun. : 90. is,-, in; l <>.-.,

(2) 22-25 mm.; 90.80, 1 16204, (10) 31-74.5 i. ; 90.70,

C6208, (1) 28 miii.: 94.32a, B6204, (19) 29.5-55 mm.;
94.32l>, 156204, (25) 25.5 54.5 mm.; 95.31a, B6204, (2) 33-

34.5 mm. ; 95.31b. B6204, (14) 32.5-47 mm. ; 95.31c, B6204,
(18) 31.5-41 mm. ; 97.40, C6303, (239) 35-105 mm. ; 100.40,
H6204, (1) mm.: 100.40, C6303, (1) 92.5 mm.: 100.65,
C6303, (1) 18 mm.; 110.35, 06303, (338) 35^109 mm.;
111.36a, 06303, (ca. 50) adults damaged and discarded at
sea; 120.45, H6204, (3) 26.5-44 mm.; 123.45, B6212, (1)
23.5 mm.: 133.35, B6212, (4) 33^0 mm.: 140.35, B6212,

(1) 28 mm.

17. Bathylagus ochot-ensu Schmidt.

Figures 8A and 9.

60.60, H6204, (3) 18.5-25 mm.; 60.70, H6204, (1) 13.5
mm.; 60.80, H6204, (4) 18-22 mm.; 60.80, C6208, (1) 37.5
mm.; 60.90, H6204, (4) 24-30 mm.; 60.100, H6204, (3) 17-
24 mm.; 60.140, H6204, (1) 23 mm.; 70.80b, B6203, (3)
18-22 mm.; 70.80-5N, B6203, (1) 21 mm.; 80.60, H6204,

(2) 49-65 mm. ; 80.70, H6204, (1) 25 mm. ; 80.90-5N, B6203,
(12) 48-80 mm.; 80.100, B6203, (1) 77 mm.; 83.69, C6303,
(6) 75.5-119 mm.; 84.70, C6303, (2) 64-86 mm.; 86.92,
C6303, (1) 55.5 mm.; 90.70, H6204, (1) 29 mm.; 108.63,
06303, (2) 56-66 mm.

This and the other three species of Bathylagus
captured were identified with a key prepared by
D.M. Cohen.

18. Bathylagus wesethi Bolin.

Figures 8B and 10.
60.60, H6204, (2) 68-72 mm.: 60.90, H6204, (6) 22-33.5
mm.; 60.100. H6204, (3) 23.5-16 mm.; 60.120, B6203, (3)
36.5-70 mm.; 60.140, H6204, (3) 28.5-38 mm.; 60.160,
B6203, ( 1 ) 27 mm. ; 60.180, H6204, ( 1 ) 25.5 mm. ; 80.55,
H6204, (6) 28.5-33 mm. ; 80.60, B6203, (1) 60.5 mm. ; 80.70,
B6203, (1) 28 mm.; 80.70, H6204, (3) 33-34 mm.; 80.90-
5N, B6203, (9) 32-52 mm.; 80.90, H6204, (11) 23.5-78
mm. ; 80.100, H6204, (3) all ca. 27 mm. ; 82.69, C6303, (12)
25-69 mm.; 83.70a, B6303, (1) 28 mm.; 86.92, C6303, (2)
39.5-47 mm.; 87.80, C6303, (3) 26.5-83.5 mm.; 90.45a,
H6105, (22) 38-75 mm.; 90.60. H6204, (1) 27 mm.; 90.70,
H6204, (.3) 23-75 mm.; 90.120, H6204, (2) 17-23 mm.;
97.40, C6303, (71) 26.5-89 mm.; 97.50, B6203, (2) 29.5-33
mm.; 100.40, H6204, (5) 28.5-42 mm.; 100.60, H6204, (2)
22.5-25 mm.; 100.65, C6303, (14) 27.5-84 mm.; 100.80,
H6204, (3) 21-82.5 mm.; 108.63, C6303, (98) 25-86 mm.;
110.46, C6303, (1) 30 mm.; 110.50, B6203, (27) 23-41.5
mm.; 120.45, H6204, (4) 27^8.5 mm.; 120.50, H6204, (5)
32-42.5 mm. ; 120.80, H6204, ( 1 ) 44 mm. ; 120.90, H6204,
(1) 21.5 mm.; 123.45, B6212, (22) 22-42 mm.; 123.50,
B6203, (1) 26.5 mm.

19. Bathylagus paoificus Gilbert.

Figure 8B.

60.60. H6204, (4) 31-65.5 mm.; 60.80, H6204, (2) 30-51
mm.; 60.100, H6204, (3) 57-92 mm.; 80.90, H6204, (3)
42.5 149 mm. : 90.48a, H6105, (1) 127 mm.

20. Bathylagus m Uteri Jordan and Gilbert.

Figure 8B.

60.80, C6208, (5) 86-128 mm.: 60.120, H6204, (2) 37.5-
45.5 mni.: 86.92, C6303, (10) 126-179 nun.; 87.80, C6303,
(5) 128-163 mm.; 90.70, C6208, (6) 128-170 mm.

638

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Figure 8. — Locations of capture of: A, Leuroglossus stilbius, Bathylagus ochotensis. B. Bathylagus wesethi,
Bathylagus paeificus, Bathylagus milleri. C, Macropinna microstoma, Dolichopteryx longipes. D,
Argyropelecus pacificus, Argyropelecus intermedins, Sternoptyx diaphana.

PELAGIC FISHES, CALIFORNIA CURRENT AREA 639

795-358 O— 66 9

Figure 9. — Bathylagus oohotensis, juvenile, 25.5 mm. SL, station 73.50, H5204.

Figure 10. — Bathylagus wesethi, juvenile, 27 mm. SL, station 92.117, S4903.

This species has at times been referred to by its
junior synonyms, B. almcanus Chapman and B.
arm' Schmidt (D. M. Cohen, personal communica-
tion).

OPI STHOPROCTIDAE

21. Macropiwna microstoma Chapman.

Figure 8C.

60.70, H6204, (2) 18.5-20.5 mm.; 60.90, H6204, (1) 20.5
mm.; 83.77, C6303, (1) 31 mm.; ,86.92, C6303, (11) 89-127
mm.; 87.80, C6303, (2) 120-133 mm.; 100.65, C6303, (1)

24.5 mm.

Previous collections in the eastern North Pacific
had indicated this to be a rare and solitary species
that did not attain a large size — no more than two
specimens had been taken together in the same net,
and the largest size reported was 40.7 mm.
(Bradbury and Cohen, 1958:59). The large
Cobb Mark-II pelagic trawl caught 11 specimens
up to L33 mm. SL in one tow; such large nets
clearly sample the bathypelagic zone more ade-
quately. The 13 larger specimens (89-133 mm.)
all appeared sexually mature; the females had
large ovarian eggs.

The ovarian eggs showed the following (John S.
MacGregor, personal communication). The larg-
est developing eggs had diameters of '2.17 to 2.53

mm. — a 95-mm. SL female had 497 eggs. The
largest remnant egg was 3.47 mm. in diameter and
had a 0.91-mm. oil drop in a 123-mm. SL female
that also contained 669 developing eggs of 0.76 to
1.01 mm. diameter.

22. Dolichopteryx longlpes (Vaillant).

Figure 8C.

83.90, C6303, (1) 74 mm.; 97.65, C6303, (1) 138 mm.;
108.63, C6303, (4) 51-180 mm.; 110.140, H0204, (1) 53.5
mm.

These specimens were identified with a key pre-
pared by D. M. Cohen.

STERNOPTYCHIDAE

23. Argyropelecus paedficus Schultz.

Figure 8D.

60.60, H6204, (2) 25-42 mm.; 60.70, H6204, (1) 30.5
mm.; 60.70, C6208, (1) 15.5 mm.; 60.90, C6208, (1) 56.5
mm.; 60.160, B6203, (2) 62.5-69.5 mm.; 80.55, H6204, (2)
17-18.5 mm.; 80.60, H6204, (6) 15-52.5 mm.; 80.60, C6208,
(8) 42-58 mm.; 80.70, H6204, (1) 19 mm.; 80.70, C6208,
(2) 47.5-54 mm.; 80.90, H6204, (2) 16.5-39 mm.; 83.74,
C6303, (105) 17-80 mm.; 83.90, C6303, (62) 19.5-63 mm.;
84.67, C6303, (9) 18-27.5 mm.; 84.70, C6303, (1) 50 mm.;
86.92, C6303, (5) 19-68 mm.: 87.80, C6303, (3) 27-78.5
mm.; 90.45a, H6105, (1) 48 mm.; 90.45, H6204, (2) 18.5-
19 mm. : 90.47, C6208, (37) 18-54 mm. ; 90.48a, H6105, (1)
24.5 mm.; 90.60, C6208, (5) 50-59.5 mm.; 90.70, H6204,

640

U.S. FISH AND WILDLIFE SERVICE

(2) 21-45 mm.; 90.70, C6208, (11) 40-02 mm.; 90.120,
H6204, (4) 12-37 mm. ; 90.140, H6204, (1) 55 mm. ; 94.32b,
B6204, (2) 17-18 mm.; 97.40, C6303, (17) 36-73 mm.;
97.50, B6203, (2) 45-50 mm. ; 97.65, C6303, (39) 22.5-68.5
mm.; 100.40, H6204, (2) 22-35.5 mm.; 100.60, H6204, (11)
24.5-66.5 mm.; 100.65, C6303, (45) 24-67 mm.; 100.90,
H6204, ( 1 ) 55 mm. ; 100.160, H6204, ( 1 ) 66.5 mm. ; 108.63,
C6303, (195) 13-69 mm.; 110.35, C6303, (1) 58 mm.;
110.46, C6303, (40) 21-67.5 mm.; 110.120, H6204, (3) 38-
62 nun.; 111.36a, C6303, (ca. 30) adults and juveniles
damaged and discarded at sea; 111.37b. C6303, (71) 21-
70 mm.; 120.45, H6204, (1) 26 mm.; 120.50. H6204, (3)
15.5-45.5 mm.; 120.70, H6204, (9) 22-56.5 mm.; 120.80,
H6204, (3) 51.5-59 mm.; 120.90, H6204, (5) 23.5-50.5
mm.; 123.50, B6203, (5) 15.5-49 mm. ; 130.40. B6212, (12)
30.5-55.5 mm.; 140.35. B6212, (8) 21.5-52 mm.

24. Argyropelecus intermedins Clarke.

Figure 8D.

60.70, H6204, (17) 9.5-23.5 mm.; 60.80, H6204. (2)
23-27 mm.: 60.90. H6204, (34) 12-34 mm.: 60.90, C6208,
(2) 15.5-18 mm.; 60.100, H6204, (3) 14-25 mm.: 60.100,
C6208, (2) 18.5-19 mm.; 60.120. B6203, (3) 23-24.5 mm.:
60.120, H6204, (8) 24-34 mm.; 60.140, H6204, (1) 26.5
nmi.; 60.160, B6203, (1) 33 mm.; 60.160, H6204, (1)
33 mm.; 70.60, C6208, (1) 12.5 mm.; 80.55, H6204, (2)
16-19 nun.; 80.70, H6204, (1) 16.5 mm.; 80.80, H6204,
(4) 22-25 mm.; 80.90, H6204, (4) 12-26 mm.; 80.140,
C6208, (5) 18.5-33 mm.; 83.77, C6303, (8) 13.5-24 mm.;
83.90, C6303, (9) 18.5-31.5 mm.; 84.68, C6303, (1)
20 mm.; 84.92, B6303, (8) 20-28 mm.; 84.70, C6303,
(1) 22 mm.; 86.92, C6303, (2) 20.5-23.5 mm.; 87.80,
C6303, (1) 23 mm.; 87.90, C6303, (1) 24 mm.; 88.105a,

B6303, (8) 18-23 mm.; 90.60, C6208, (2) 16.5-19 mm.;
90.70, H6204, (1) 19 mm.; 90.70 C6208, (2) 17 mm.;
90.100, C6208, (15) 15-31.5 mm.; 90.120, H6204, (1)

14 mm.; 90.140, H6204, (1) 28.5 mm.; 90.150, C6208, (1)
21 mm.; 90.200, C6208, (1) 28 mm.; 100.60, H6204, (1)

15 mm.; 100.65, C6303, (3) 21.5-29 mm.; 100.80, H6204,
(3) 19.5-28 mm.; 100.90, H62u., ^3.5-28.5 mm.;
100.120, H6204, (3) 24-26 mm.; 100.140, H6204, (2) 18.5-
26.5 mm.; 110.120, H6204, (1) 20 mm.; 110.140, H6204,
(1) 23.5 mm.; 110.160, H6204, (3) 11-26 mm.; 120.80,
H6204, (9) 13.5-23.5 mm.; 120.90, H6204, (1) 15 mm.

25. Argyropelecus lychnus Garman.

Figures 11 and 13A.

87.80, C6303. (1) 25 mm. ; 90.45, H6204, (2) 15-17.5 mm. ;
90.47, C6208, (1) 32 mm.; 90.48a, H6105, (2) 17.5-19.5
mm.; 90.120, H6204, (1) 12 mm.; 94.29a, C6208, (2) 30-
30.5 mm. ; 97.40, C6303, (4) 14-15.5 mm. ; 97.50, B6203, (2)
21-39 mm.; 100.60, H6204, (2) 12-46 mm.; 100.90, H6204,
(1) 48 mm.; 108.63, C6303, (2) 49-71.5 mm.; 110.35,
C6303, (1) 17 mm.; 110.140. H6204, (1) 17.5 mm.; 120.45,
H6204, (9) 14.5-27 mm.; 120.60, H6204, (2) 15.5 mm.;
120.80, H6204, (18) 20-61 mm.; 123.50, B6203, (6)
18-44 mm.; 130.40, B6212, (30) 17-58.5 mm.; 133.35,
B6212, (1) 24.5 mm.; 137.50, B6203, (8) 19-43.5 mm.;
140.35, B6212, (3) 31-39 mm.

26. Argyropelecus hawaiensis Schultz.

Figures 12 and 13A.

60.60, H6204, (1) 12.5 mm.; 60.70, H6204, (3) 11-14.5
mm.; 60.80, H6204, (1) 16 mm.; 60.80, C6208, (2) 27-29
mm.; 60.90, H6204, (1) 13 mm.; 60.90, C6208, (2) 23-27
mm.; 60.100, H6204, (1) 30.5 mm.; 60.100, C6208, (4)

* * * - * . * v. . '

fff^

Figure 11. — Argyropelecus lychnus, juvenile, 17 mm. SL, station 110.140, H6204.
PELAGIC FISHES, CALIFORNIA CURRENT AREA

641

20.5-56 mm.; 60.120, BG203. (4) 36-39 mm.; 60.120,
H6204, (1) 43 mm.; 60.140, H6204, (1) 37 mm.; 60.160,
B6303, (2) 39.5-44 mm.; 60.160, H6204, (3) 15-51 mm.;
60.200, H6204, (2) 48-53 mm.; 70.60, C6208, (2) 20
mm.; 70.80b, B6203, (2) 14-38 mm.; 70.100, C6208, (1)
38 mm.; 80.55, H6204, (1) 37 mm.; 80.60, C6208, (5)
14.5-21 mm.; 80.70, C6208, (3) 18.5-19.5 mm.; 80.80,
H6204, (4) 24-43 mm.; 80.90, B6203, (2) 18.5-44.5 mm.;
80.100, B6203, (5) 36-50 mm.; 80.140, C6208, (2) 44-56
mm.; 80.150, C6208, (1) 50.5 mm.; 83.70c, B6303, (1)
39.5 mm.; 83.77, C6303, (18) 23-40.5 mm.; 83.90, C6303,
(10) 18-47.5 mm.; 84.67, C6303, (9) 16-35.5 mm.; 84.68,
C6303. (3) 20-35 mm.; 84.70, C6303, (6) 20-37.5 mm.;
84.92, B6303, (9) 19.5-45.5 mm.; 86.92, C6303, (5) 37^3
mm.; 87.80, C6303, (1) 28 mm.; 90.32, B6203, (3) 16-18
mm.; 90.45, H6204, (1) 15.5 mm.; 90.47, C6208, (1) 46.5
mm.; 90.60, C6208, (1) 49.5 mm.; 90.180, C6208, (1) 58
mm.; 93.31, C6303, (4) 25-39 mm.; 94.29a, C6208, (3)
28-29.5 mm.; 97.40, C6303, (17) 18-43.5 mm.; 97.50,
B6203, (1) 26.5 mm.; 97.65, C6303, (4) 30.5-43 mm.;
100.40, H6204, (1) 21.5 mm.; 100.40, C6303, (1) 40 mm.;
100.60, H6204, (2) 14.5-39 mm.; 100.65, C6303, (5) 33-
43.5 mm.; 100.80, H6204, (1) 20 mm.; 100.90, H6204, (1)
35.5 mm.; 100.120, H6204, (1) 62 mm.; 103.50, C6303, (1)
22 mm.; 108.63, C6303, (2) 25-28 mm.; 110.46, C6303, (1)
26.5 mm.; 110.50, B6203, (2) 23-47.5 mm.; 120.60, H6204,
(2) 16-53 mm.; 123.50, B6203, (4) 19.5-60.5 mm.

Argyropelecus hawaiensis was first described
as a subspecies of Argyropelecus lychnus by
Schultz ( 1961 :615) . With uncertainty, prompted
by the small number of available specimens,
Schultz recognized a complex of three subspecies :

A. I. lychnus Garman, eastern Pacific and

Atlantic;

A. I. hawaiensis Schultz, around and north of

Hawaiian Islands;

A. I. sladeni Regan, western Pacific and Indian

Oceans.

In none of our specimens of this type is the
body depth of as great a percentage of standard
length as that given for A. sladeni by Schultz
(1961 and 1937:4), and we do not consider A.
sladeni, if valid, to occur within our area of study.

We conclude that A. hawaiensis is a species dis-
tinct from A. lychnus. In our study area A. ha-
waiensis has the more temperate distribution, and
A. lychnus, the more subtropical (fig. 13A) ; but
both species, often represented by specimens of
similar size, were taken together at 11 stations of
the survey. With a comparable size series of ju-
venile and adult specimens of about 12 to 62 mm.
SL, certain character differences readily dis-
tinguish the two species.

The upper preopercular spine in juvenile A.
hawaiensis curves outward and slightly dorsopos-
teriad in a nearly even arch, while in juvenile A.
lychnus it curves outward and slightly ventropos-
teriad at its distal end. With increased body
length this spine becomes relatively shorter and
thicker in both species, but more strongly hooked
upward in A. hawaiensis and more strongly
hooked downward and backward in A. lychnus.

Juvenile specimens of A. hawaiensis possess
considerably more lateral pigment along the pos-
terior portion of the body (fig. 12). At about 14

■Ml ;>•' '

^taSSsatt*' v

642

Kkiure 12. — AryyropelecuH hawa-i^nsUs. juvenile, 17 mm. SL, station 84.67, C6303.

U.S. FISH AND WILDLIFE SERVICE

mm. SL, A. hmoalensis has a vertical band of pig-
ment above the subcaudal photophores, a medial
patch over the anal photophores, and a row of
pigment spots along the lateral midline anterior
to the anal photophores Specimens of A. lychnus
of the same size possess no pigment on the poste-
rior portion of the body, and pigment in the areas
above the subcaudal and anal photophores begins
to show only faintly at about 17 mm.

At about 25 mm. SL, body pigment extends
backward to the posterior edge of the anal group
of photophores on both species. The vertical area
between the anal and subcaudal photophores in A.
hawaiensis bears a row of pigment spots along the
lateral midline (a posterior extension of the an-
terior row mentioned for the 14-mm. size) . The
area above the subcaudal photophores is strongly
pigmented on both species and gives, on gross ex-
amination, the impression of a colorless, vertical
band between the anal and subcaudal groups of
photophores. This "banded" area fills in with
pigment dorsoventrally in adults, and in 25-mm.
specimens of A. hawaiensis the beginning of this
process is evident. Specimens of the same size of
^4. lychnus have little or no pigment in this area,
and the lower portion of this area immediately
between the anal and subcaudal photophores may
be void of pigment in specimens of A. lychnus as
large as 42 mm. SL.

Body depth in relation to standard length over-
laps between the two species in the smaller juve-
nile sizes. At larger sizes A. lychnus has the deeper
body; above 32 mm. SL the body depth of A.
lychnus is about 62-71 percent SL and that of A.
hawaiensis about 54—60 percent SL.

An additional character useful in separating the
two forms at sizes of about 45 mm. SL and larger
is the formation of small spines along the ventral
edges of the scales overlying the subcaudal photo-
phores on specimens of A. lychnus. The spines
start to develop on specimens between 40 and 45
mm. SL. These spines are absent on all specimens
of A. hatoaiensis examined including the largest in
our collections (62 mm. SL) and one of the para-
types at Scripps Institution of Oceanography
(SIOH53-372, 52 mm.).

27. Argyropelecus sp.

110.50, B6203, (1) 15 mm.

This damaged specimen cannot be specifically
identified.

28. Sternoptyx diaplunui Hermann.

Figure 8D.
60.80. H6204, (1) 43 mm.; 60.100, H6204, (3) 13-18.5
mm.; 60.180, H6204, (5) 8-29 mm.; 70.200, H6204, (6)
11-37 mm.; 80.70, H6204, (2) 14.5-16 mm.; 80.100, H6204,

(1) 34 mm.; 83.77, C6303, (1) 25 mm.; 84.67, €6303, (1)
22.5 mm.; 86.92, C6303, (13) 14.5-57 mm.; 87.80, 06303,
(3) 19-59 mm.; 87.90, C6303, (1) 54 mm.; 90.45a, H6105,

(2) 24-37 mm. ; 90.48a, H6105, (1) 27 mm. ; 90.160, H6204,
(5) 24-42.5 mm.; 90.180, H6204, (1) 19.5 mm.; 90.200,
H6204, (4) 7-27.5 mm. ; 95.31a, B6204, (1) 15 mm. ; 100.65,
C6303, (1) 28 mm. ; 100.80, H6204, (4) 15-37 mm. ; 100.140,
H6204, (3) 28.5-36.5 mm.; 100.160, H6204, (3) 13-28.5
mm.; 110.120, H6204, (3) 32-39.5 mm.; 110.160, H6204,
(10) 12.5-51 mm.; 120.45, H6204, (1) 32.5 mm.; 120.50.
H6204, (1) 26.5 mm.; 120.90, H6204, (1) 31 mm.

29.

GONOSTOMATIDAE

Gonostoma atlanticum Norman?

Figure 13B.
80.55, H6204, (1) 65 mm.; 80.80, H6204, (1) 45 mm.;
80.90, H6204, (1) 56 mm.; 90.100, C6208, (1) 28.5 mm.;
97.65, C6303. (1) 52 mm.; 100.120, H6204, (1) 63.5 mm.

These specimens appear to represent G. atlanti-
cum Norman, but are only tentatively identified
because of the arrangement of the maxillary teeth.
Grey (1960: 107) described the last four enlarged
maxillary teeth of G. atlanticum as having no in-
terspace teeth. The above specimens possess inter-
space teeth between the enlarged teeth on the
maxillary.

30. Gonostoma ebelmgi Grey.

Figure 13B.
90.160, C6208, (1) 124 mm.

This specimen represents an appreciable range
extension from the original area of its description,
the Marshall Island area, by Grey (1960:109).

31. Cyclothone Goode and Bean.

This is probably the most abundant deepwater
genus of fishes off the coast of California. How-
ever, the collection data indicate that hauls made
shallower than 550 m. do not adequately sample
their population. Of the several thousand speci-
mens taken by the IKMWT (the most efficient
device in present use for the consistent capture of
these fishes), only about 11 percent were, taken
where the net was fishing above an estimated depth
of 550 m., and nearly all of these fish were C. sig-
nata and C. acclinidens — apparently the two most
abundant species in the California-Baja California
area at any depth.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

643

Lj<- >L

•n

1 , 7—

o o o o o o

o o

WSAN FRANCISCO

o o

*■><>.

o o o o o

o ooV^

° 8

Po.

o •

0 8 o

•

JD/ SAN

8 8*f°'EG0 /
oo " V
o ) JL \

•

° \{ }

•

•til 1

0 J I \

v„.

• \ 1 (

O ARGYROPELECUS HAWAIENSIS

• ARGYROPELECUS LYCHNUS

'fo.

■ >
V SAN FRANCISCO

~4>.

o o

• o

/ SAN

4 DIEGO

^0.

i J

?»•

O GONOSTOMA ATLANTICUM ?
• GONOSTOMA EBELINGI

•to. '<-•>

*• -4

8 8

88808

080 ooo<9'
o 8 0

8 o 8 o° 00 gg

8 o
8 8 8 o 80

800

o o o 00 ,
o

O CYCLOTHONE SIGNATA
• CYCLOTHONE SP

O CYCLOTHONE CANINA

• CYCLOTHONE ACCLINIDENS

A CYCLOTHONE ATRARIA

Figure 13. — Tyocations of capture of: A, Argyropelectu hawaieiMis, Argyropelectu lychnus. B, Qonostoma atlanticumf,
Oonostomn el '' h<mc signata, Cyclothone sp. I), Cyclothone canina, Cyclothone acclinidens, Cyclo-

thone iiinn

till

U.S. FISH AND WILDLIFE SERVICE

Our first attempts to identify the abundant spec-
imens of Cy clot hone in the survey collections by
literature existing at that time were unsatisfactory.
A detailed examination was made of this group,
and the results and conclusions are summarized be-
low. At least, five species of Cyclothone are repre-
sented in our collections.

Some of the specimens of G . signata from the
more otfshore localities may represent the tersely
described and inadequately know:. C. alba Brauer
(B. N. Kobayashi, personal communication).

The form we designate as Cyclothone sp. (num-
ber 33) may be an un described species. There is a
possibility that it represents C. pseadopallida, re-
cently described by Mukhacheva (1964) (B. N.
Kobayashi, personal communication).

Although Cyclothone microdon (Giinther) has
been reported from California waters, none of the
specimens taken in the survey can be definitely
attributed to this species. C. pallida Brauer has

also been reported off California, but we find that
the form here closely resembles Gilbert's descrip-
tion of C. canina ( 1905 :604) ; especially significant
is Gilbert's description of the palatine and ptery-
goid teeth of C. canina — "palatine teeth confined to
the anterior end, in two small detached groups —
pterygoid teeth all small, forming a single, some-
what irregular series." Actually his two small de-
tached groups of palatines were one group (an-
terior) of palatines and one group (posterior) of
pterygoids, as is typical of the genus. The irregu-
lar series of pterygoid teeth is thus far unique in
this genus. They lie along the upper edge of the
bone for nearly its entire length (fig. 14 C) ; how-
ever, the size and number of these teeth may be in-
traspecifically variable. As mentioned, this fact
alone separates C. canina from other California
species, and, unless the type specimens of G. pallida
are found to contain such an arrangement of teeth
(all other characters being equal), the two forms
must certainly stand as distinct.

'^^.l^-^wsfca'.s^vr.K.tiia***'"

'ffl&Sss/J.JSj A*"

',*■*■'

;-.- —

Figure 14. — Cyclothone. A, upper jaw of C. acclinidens showing the arrangement of teeth along the maxillary and
premaxillary ; the premaxillary is at the extreme left ; the long slender bone possessing most of the teeth is the
maxillary ; and the small bone at upper right is the supramaxillary. B, upper jaw of C. canina. C, palatine and
pterygoid bones of C. canina showing the unique row of teeth on the entopterygoid ; the anterior end is at the left.
D, posterior part of the first gill arch of Cyclothone sp. showing the typical arrangement of two gillrakers at the
angle. E, posterior part of the first gill arch of C. signata showing the unique arrangement of only one gillraker
at the angle of the epibranchial and eeratobranehial bones. F, branchiostegal membrane and rays of C. signata
showing photophore and pigment arrangement. G, branchiostegal membrane and rays of C. acclinidens showing
photophore and pigment arrangement.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

645

All California species posses a photophore im-
mediately below the eye and slightly forward of
the eye's midline, a photophore above the posterior
extremity of the maxillary on a level with the eye,
and a photophore immediately behind the angle of
the preoperele. Other photophores are mentioned
in table 2. The photophores between the bases of
the. pelvic and anal fins have not been dealt with as
a separate imit because an exact dividing line be-
tween these and the anal-to-caudal group is diffi-
cult to determine in many fish. Generally, C. sig-
nata has four photophores between the pelvics and
anal and the other species have five. The first two
pairs in this group are markedly close-set in Cy-
clothone sp., while the interspaces are equal or
slightly greater posteriorly in the other species.

KEY TO ADULTS OF THE CALIFORNIA AND BAJA
CALIFORNIA SPECIES OF THE GENUS CYCLO-
THONE

I. Branehiostegal membranes without pigment except
for a thin line over all but a few of the most posterior
rays and along the upper and lower margins (fig. 14F).
Roof of mouth pigmented mainly along its midline. Gill
cavities nearly colorless. Gillrakers totaling less than
20 on the lateral side of the first gill arch. One or two
gillrakers at angle of first gill arch.

A. Total gillrakers on lateral side of first gill arch not
more than 15 (usually 4+10). Only one gillraker at

angle of first gill arch (fig. 14E)

C. signata Garman.

B. Total gillrakers on lateral side of first arch 17-19

(the position of the medial rakers on the arch ac-
centuated by a thin pigment line). Two gillrakers
at angle of first gill arch (fig. 14D).__Cj/c7oi/ioHe sp.
II. Entire branehiostegal membranes and most of the
oral and gill cavities darkly pigmented (fig. 14G). Gill-
rakers more than 20 on the lateral side of the first gill
arch. Two gillrakers at angle of first gill arch.

A. None of the teeth on the premaxillary directed
strongly anterioventrad ; generally, every third or
fourth of the oblique teeth enlarged ; canines con-
spicuous on premaxillary (fig. 14B). Entoptery-
goid teeth not confined to an anterior cluster (fig.
14C. C. catiina Gilbert.

B. Teeth along posterior three quarters of maxillary
directed strongly anterioventrad, generally increas-
ing in obliqueness and decreasing in size anteriorly ;
no conspicuous canines on the premaxillary (fig.
14A). Entopterygoid teeth confined to an anterior
cluster.

1. Branehiostegal photophores 8 or 9. Branehios-
tegal rays 12. Pigmentation dark brown and
usually persistent ; photophores relatively small ;
scale pockets conspicuous. C. atraria Gilbert.

2. Branehiostegal photophores 10 or 11. Bran-
ehiostegal rays 14. Pigmentation light brown or
greyish ; photophores of relatively moderate size ;

scale pockets not conspicuous.

C. acclinidens Garman.

32. Cyclothone canina Gilbert.

Fifrures 13D. 14B. and 14C.

60.60. H6204, (3) 24-61 mm.: 60.80, H6204, (1) 62mm.;
60.100, H6204, (4) 24-48.5 mm.: 60.140, H6204, (3) 24-49
mm.; 60.180, H6204, (6) 22-70 mm.; 70.200, H6204, (2)
24.5-63.5 mm.; 80.70, H6204, (1) 56 mm.; 86.92, C6303,

Table 2. — Comparative morphological data for the five species of Cyclothone occurring off the coasts of California and Baja

California

Morphological

Species

character

signata

Sp. No. 33

canina

acclinidens

atraria

13-14

13-15 .

14-15

13-15

13-14.

19-20

19-21—

18-19

18-20.

18-19.

8-10...

9...

9-10

9-10.

3-44-9-10

14 .

12.

6-7+11-12

9-10+14-16

7-8+14-15

8-9+14.

13+18-19...

12-13+19-20 .

13+18-19

13+18

13+19.

Photophores:

8-9

9-11

9-10

10-11

8-9.

7+1 or 7+2

7+2

7+2.

i:i

13.

Small .

20-21 -

20-21

18-19

19-21.

Moderately slender

Pale — rarely pigment

flecks on flanks.
Yes

Moderately slender. __

Brown flanks or

grey cast.
Yes

Pale or flanks brown . .
Yes

others.

Yes

No.

and Interhaemals.

Slight irregular..

Moderate

Usually absent, mi-
nute i( present.
Immediately behind

|ii'l\ if hasc

2-4 distinct canines

Irregular, nearly

forming canines.
Very strong

forming canines.

Position of anus between pelvics

Much nearer pelvics

than anal.
No ..

Midway or less

d anal.

Yes.

2...

2 .

ireh.

646

U.S. FISH AND WILDLIFE SERVICE

(4) 31.5-57 mm.; 87.80. C6303. (1) 58.5 mm.: 87.90,
C6303, ill 43.5 mm.; 90.120, H6204, (3) 43-58 mm.;
90.160. H6204, (4) 31-59 mm.; 90.200. IK;2(M. (9) 30.5-
58.5 mm.; 100.60. H6204, (6) 52-62 mm.; 100.80. H6204,
(2) 41-51.5 mm.; 100.100, H6204, (5) 40-62 mm.; 100.140.
H6204, (4) 31-59 mm.: 100.160, H6204. (6) 47-60 mm. :
110.140. H02O4, (2) 25-33 mm.: 110.160. H6204, (8) 28-
60 mm. ; 120.50, H6204, (2> 56-58 mm. : 120.70. HH204, (1)
44 mm.; 120.90. H6204, (4 I 42-62 mm.

33. (' yd of hone sp.

Figures 13C and 14D.

60.60. H6204. (8) 27-12.5 mm.; 60.80, H6204, (16) 18-
47 mm.; 60.90, H6204, (6) 19-31.5 mm.; 60.100, H6204.
(34) 24-17 mm.: 60.140. H6204, 111) 26-47.5 mm.; 60.180,
H6204, (27) 15-46 mm. ; 70.200, H6204, (20) 21.5-42mm.;
80.90, H6204, (2) 35-37.5 mm.; 83.77, C6303, (6) 32-45
mm.: Mini'. C6303, (7) 27-37.5 mm.: 90.48a, H6105, (3)
36.5-11 mm.; 90.120. H6204. (7) 30.5-36 mm.; 90.160,
H6204, (4) 12-36 mm.; 90.180. H6204, (1) 28.5 mm.;
90.200, H6204. (11) 20-38 mm.: 97.65. C6303, (2) 27
mm. : 100.65. C6303, (1) 26.5 mm. ; 100.80, H6204, (6) 35.5-
41.5 mm.; 100.100. H6204, (4) 36-3S.5 mm.; 100.140,
H6204, (9) 18-40 mm.: 100.160, H6204, (9) 29-38.5 mm.;
108.63, C6303, (1) 27 mm. : 110.160, H6204. (2) 35-40 mm.

34. Cyclothotw signata Garman.

Figures 13C. 14B. and 14F.

60.60, H6204. ( 95 ) 19-36 mm. ; 60.60, C6208, (1) 26 mm. ;
60.70. H6204, (7) 19-30 mm.; 60.80, H6204. (108) 15-36
mm. ; 60.90, H6204, (9) 24-29 mm. ; 60.100, H6204, (99) 14-
38.5 mm.; 60.140, H6204, (128) 13.5-36 mm.; 60.180,
H6204, (97) 16-34 mm.; 70.200, H6204, (83) 18.5-34.5
mm.; 79.54, B6303, (9) 16.5-29.5 mm.; 80.55, H6204, (23)
19-29 mm.; 80.60, H6204, (49) 16-31 mm.; 80.70, H6204.
(98) 12.5-34.5 mm.; 80.70, C6208, (1) 22.5 mm.; 80.75,
B6303, (1) 20 mm.; 80.80, H6204, (37) 14-32 mm.; 80.90,
H6204, (152) 17-34 mm.; 80.100, H6204, (93) 20-30 mm.:
80.170. C6208. ( 1 ) 24 mm. ; 80.200, H6204, ( 1 ) 28.5 mm. ;
83.77, C6303, (114) 21.5-33 mm.; 83.90. C6303, (67) 17.5-
30 mm.; ,84.70. C6303. (1) 28 mm.; 86.92, C6303, (73) 21-
34 mm. : 87.80, C6303. (3) 24.5-33.5 mm. : 87.90, C6303, (2)
28-38 mm.; 90.45a, H6105, (16) 23.5-33.5 mm.; 90.48a,
H6105, (132) 16-33 mm.; 90.48b, H6105, (9) 20-30 mm. :
90.60, H6204, (2) 24-3S mm.; 90.60, C6208, (21) 16-26
mm. ; 90.70. H6204, (1) 21 mm. ; 90.70, C6208, (15) 21.5-32.5
mm.; 90.100, C6208, (17) 17-26 mm.: 90.120, H6204, (92)
12.5-36 mm.: 90.140, H6204, (1) 19.5 mm.: 90.140, C6208,
(1) 25 mm.: 90.160, H6204, (51) 16-32.5 mm.; 90.160,
C6208, (1) 30 mm.; 90.200, H6204, (41) 15-33 mm.; 97.40,
C6303, (21) 22-30 mm.; 97.65, C6303, (94) 17.5-38 mm.;
100.60, H6204, (6) 25-33 mm.; 100.65, C6303, (409) 17-35
mm. ; 100.80, H6204, (91) 17-36 mm. ; 100.100, H6204, (29)
10-34.5 mm.: 100.140. H6204, (22) 18.5-35 mm.; 100.160,
H6204. (31) 17.5-35.5 mm.: 108.63, C6303. (149) 19.5-36
mm.; 110.35, C6303. (3) 26-30 mm.: 110.46, C6303, (29)
23-33 mm.: 110.120, H6204, (25) 22-35 mm.; 110.140,
H6204, ( 13) 18-28.5 mm. ; 110.160, H6204, (33) 16-32 mm. ;
111.37b, C6303. (9) 25-30 mm.; 118.43, B6212, (24) 21.5-
33.5 mm.; 120.45, H6204. (12) 20-29 mm.; 120.50, H6204,

(2) 27-32 mm.; 120.60, 11(1204, (4) 25-30 mm.; 120.70.
H6204, (8) 22.5-33 mm. ; 120.90, H6204, (16) 22.5-32 mm. ;
123.50, B6203, (1) 22 mm.: 130.40, B6212, (5) 22.5-26.5
mm.; 140.35, B6212. (14) 23.5-32 mm.

35. Cyclothone acclinidens Garman.

Figures 13D, 14A. and 14G.

60.60, H6204, (33) 15-54.5 mm.; 60.70, H6204, (3) 27-
42.5 mm.; 60.80, H6204, (13) 26-55.5 mm.; 60.90. H6204,

(I) 34 mm. ; 60.100, H6204, (10) 28-55 mm. ; 60.140, H6204.
(37) 27-56.5 mm. ; 60.180, H6204, (7) 31.5-58 mm. : 70.200,
H6204, (5) 30.5-40 mm.; 80.55. H6204, (41) 20-40 mm.;
80.60, H6204, (4) 21^6 mm. ; 80.70, H6204, (23) 22.5-58
mm.; 80.80, H6204, (1) 31 mm.; 80.90, H6204, (66) 20.5-
57 mm.; 80.100, H6204, (32) 21-45.5 mm.; 83.77, C6303,
(86) 21-37 mm. ; 84.70, C6303, (4) 35-53 mm. ; 86.92, C6303,
(141) 26.5-56 mm.; 87.80, C6303, (57) 30-55 mm.; 87.90,
C6303, (6) 32.5-50 mm.; 90.45a, H6105, (71) 23.5-43.5
mm.; 90.48a, H6105, (207) 15.5-43.5 mm.; 90.48b, H6105,
(10) 16.5-24.5 mm. ; 90.120. H6204 (29) 19-56 mm. ; 90.160,
H6204, (6) 32.5-50.5 mm. ; 90.200, H6204, (16) 23-58 mm. ;
95.31a, B6204, (2) 26-31 mm.; 97.65, C6303, (7) 17.5-32
mm. ; 100.60, H6204, (98) 20.5-53 mm. ; 100.65. C6303, (12)
25-45.5 mm.: 100.80, H6204. (62) 23-58 mm.; 100.100,
H6204, (65) 14-56 mm ; 100.140, H6204, (18) 25.5-54 mm. ;
100.160, H6204, (16) 24-57 mm. ; 108.63, C6303, (12) 18-34
mm.; 110.35, C6303, (1) 26 mm.; 110.46, C6303, (3) 22-27
mm.; 110.120. H6204, (88) 19-56 mm.; 110.140, H6204.

(II) 19-35 mm. ; 110.160, H6204, (35) 16-56 mm. ; 111.37b,
06303, (5) 17-30 mm.; 118.43, B6212, (16) 17.5-31 mm.;
120.45, H6204, (4) 21.5-25.5 mm.; 120.50, H6204, (174)
17-51 mm. ; 120.60, H6204, (1) 25 mm. ; 120.70, H6204 (152)
14.5-55 mm.; 120.90, H6204, (276) 19.5-63 mm.; 130.40,
B6212, (81) 13.5-38.5 mm. ; 133.35, B6212, (3) 17-22 mm. ;
140.35, B6212, (77) 14-40 mm.

36. Cyclothone atrarla Gilbert.

Figure 13D.

60.60, H6204. (4) 36.5-50 mm.; 60.70, H6204, (1) 51
mm.; 60.80, H6204, (5) 21-49.5 mm.; 60.100, H6204, (6)
31-56 mm.; 60.140, H6204. (6) 37.5-51.5 mm.; 60.180,
H6204, (11) 28-51 mm.; 70.200, H6204. (9) 28-54.5 mm.;
80.90, H6204, (1) 55 mm.; 120.70, H6204, (1) 53.5 mm.

37. Diplophos sp.

133.35, B6212, (1) 50 mm.

It is not possible to identify this slightly dam-
aged specimen specifically from the revision by
Grey (1960:57-125).

38. Valenciennellus tripiinctulatus (Esmark) ?

Figure 15A.

70.200, H6204, (1) 28 mm.; 73.200, B6203, (2) 25
mm.; 90.120, H6204, (1) dis. adult; 90.160, H6204, (1)
ca. 10 mm. ; 90.180, H6204, (1) 25 mm. ; 90.200, H6204, (1)
25.5 mm.

This specific identification is questioned because
most of these specimens have four groups of anal

PELAGIC FISHES, CALIFORNIA CURRENT AREA

647

to caudal (AC) photophores rather than the five
groups reportedly characteristic for V. trlpunctu-
latus; this difference may indicate that these speci-
mens are actually V. stellatus Garman. This
problem was discussed by Grey (1960: 68).

39. Danaphos oculatus (Garman).

Figure 15A.

60.60, H6204, (1) 19.5 mm.; 60.70, H6204, (7) 20-25
mm. ; 60.80, H6204, (4) 22-38 mm. ; 60.90, H6204, (7) 20.5-
31 mm.; 60.90, C6208, (2) 32 mm.; 60.100, H6204, (2)
22.5-23.5 mm.; 60.120, H6204, (21) 29-40 mm.; 60.160,
B6203, (3) 34.5-36 mm. ; 60.160, H6204, (1) 31 mm. ; 60.180,
H6204, (1) 40 mm.; 70.60, C6208, (1) 23 mm.; 70.200,
H6204, (1) 44 mm.; 80.55, H6204, (3) 30-30.5 mm.; 80.60,
H6204, (1) 27 mm. ; 80.70, H6204, (3) 26.5-38.5 mm. ; 80.75,
B6303, (1) 22.5 mm. ; 80.80, H6204, (14) 26-39 mm. ; 80.90,
H6204, (7) 24-38 mm.; 80.100, H6204, (3) 30-32 mm.;
80.140, C6208, (1) 30 mm.; 83.77, 06303, (44) 27-40 mm.;
83.90, C6303, (61) 23-40.5 mm.; 84.67, C6303, (3) 29-30
mm.; 86.92, C6303, (4) 28-30 mm. ; 87.80, C6303, (4) 34.5-
40 mm.; 90.32, B6203, (2) 33 mm.; 90.45a, H6105, (1)
32.5 mm. ; 90.60, H6204, (1) adult, damaged; 90.70, H6204,
(4) 31-37 mm. ; 90.110, B6203, (1) 36 mm. ; 90.120, H6204,
(1) 31 mm.; 90.140, C6208, (2) 24-30.5 mm,; 90.160,
H6204, (1) 37.5 mm.; 97.65, C6303, (3) 20.5-39 mm.;
100.60, H6204, (1) 34 mm.; 100.65, C6303, (18) 25.5-39
mm.; 100.80, H6204, (9) 31-35 mm.; 100.90, H6204, (1) 34
mm. ; 100.160, H6204, (1) 32.5 mm. ; 108.63, C6303, (5) 29-
38 mm.; 110.120, H6204, (2) 25-35 mm.; 110.140, H6204,
(1) 29 mm.; 110.160, H6204, (2) 32.5-35 mm.; 120.45,
H6204, (1) 29 mm.; 120.60, H6204, (1) 32 mm.; 120.70,
H6204, (1) 34 mm.; 140.35, B6212, (1) 34 mm.

40. Vinciguerria nimbaria (Jordan and Wil-
liams).

Figure 15B.

00.200a, B6203, (2) 24.5-38 mm.; 73.200, B6203, (1) 39
mm. ; 80.140, C6208, (1) 23.5 mm. ; 80.170, C6208, (2) 16-22
mm.; 90.110, C6303, (4) 20-43 mm.; 90.150, C6208, (10)
.ill ca.»?6 mm.; 90.160, H6204, (2) 18-19.5 mm.; 90.180,
H6204, <1) 39.5 mm. ; 93.100, C6303, (1) 21.5 mm. ; 100.140,
H6204, (1) 20 mm.; 100.160, H6204, (1) 26 mm.

41. Vinciguerria, lucetla (Garman).

Figure 15B.

S3.77, C6303. (1) 34 mm.; 83.90, C6303, (1) 35.5 mm.;
87.80, C6303, (1) 42 mm. ; 90.48b, H6105, (1) ca. 10 mm.;
90.120, C620S, (5) 16.5-28 mm.; 90.140, H6204, (1) 49.5
mm.; 90.150, C6208, (7) 17-19 mm.; 100.100, H6204, (3)
32.5-42 mm.; 100.160, H6204, (1) 24 mm.; 110.100, H6204,
(1) 24 mm.; 110.120, H6204, (3) 28-44 mm.; 110.140,
II0204, (1) 19 mm.; 120.45, B6212, (24) 17-22.5 mm.;
120.60, H6204. (4) 34-36 mm.; 120.70, H6204, (4) 28-41
mm. ; 120.80, H6204, (10) 31.5-47 mm. ; 120.90, H6204, (19)
27.5-49 mm.; 123.45, B6212, (158) 18-44.5 mm.; 123.50,
isiiLUi. (3) 22-27 mm.; 127.45, B6212, (7) 21-32.5 mm.;
130.40, B6212, (142) 15-56.5 mm.; 133.35, B6212, (87)

15.5-53.5 mm. ; 137.35, B6212, (536) 12.5-48.5 mm. ; 137.50,
B6203, (7) 28.5-52 mm.; 140.35, B6212, (388) 14.5-50 mm.

42. Vinciguerria poweriae (Cocco).

Figure 15B.

60.120, B6203, (2) 24-28 mm.; 60.160, B6203, (1) 26
mm.; 60.180, B6203, (1) 24.5 mm.; 60.200, H6204, (1) 31
mm.; 70.200, H6204, (1) 18mm.; 73.200, B6203, (2) 27-30
mm.; 80.140, C6208, (2) 23-23.5 mm.; 80.200, C6208, (1)
34 mm.; 83.77, C6303, (2) 23-28 mm.; 90.110, C6303, (8)
26-33.5 mm.; 90.120, C6208, (2) 17.5 mm.; 90.124, C6208,

(2) 16 mm.; 90.160, H6204, (2) 17.5-18 mm.; 90.160,
C6208, (1) 27.5 mm.; 90.200, H6204, (1) 17.5 mm.; 92.115,
B6303, (1) 18.5 mm.

The specimens from station 83.77 are closer to
the continent (about 195 km. (120 miles) offshore)
than is usual for this species (see Ahlstrom and
Counts 1958, fig. 25).

43. Vinciguerria sp.

90.140, 06208, (3) 18-20 mm.

These damaged specimens are unidentifiable to
species.

44. Ichthyococcus elongatus Imai.

Figure 15C.
80.70, H6204, (1) 65 mm.

This record extends the known range of the
species from Japan and lat. 41°42' N., long. 150°
00' W. to near the coast of California and also
extends its geographical range into that of /. ir-
regularis as described by Rechnitzer and Bohlke
(1958).

45. Ichthyococcus irregularis Rechnitzer and
Bohlke.

Figure 15C.

90.47, 06208, (1) 37 mm.; 100.60, H6204. (1) 61.5 mm.;
108.63, C6303, (1) 51 mm.; 120.90, H6204, (1) 41 mm.

STOMIATIDAE

46. Stomias atriventer Garman.

Figure 15D.

82.69, 06303, (1) 59 mm.; 84.70, C6303, (1) 209 mm.;
86.92, 06303, (5) 52.5-227 mm.; 87.80, C6303, (2) 195-218
mm.; 87.90, O6303, (1) 74 mm.; 90.45a, H6105, (1) 202
mm.; 90.48a, H6105, (1) 116 mm.; 90.110, C6303, (1) 228
mm.; 95.31a, B6204, (1) 158 mm.; 97.40, C6303, (1) 232
mm.; 97.65, C6303, (1) 45 mm.; 100.40, H6204, (3) 122-
204 mm.; 100.40, C6303, (1) 161 mm.; 100.100, H6204, (1)
29 mm.; 108.63, C6303, (24) 128-235 mm.; 110.35, C6303,

(3) 123-205 mm.; 110.40, II6204, (1) 142 mm.; 110.46,
O6303, (7) 180-226 mm.; 120.45, H6204, (8) 138-214 mm. ;
120.45, B6212, (1) 48 mm.; 120.50, H6204, (1) 212 mm.;
120.60, H6204, (1) 131 mm.; 120.80, H6204, (1) 186 mm.;

648

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Figure 15. — Locations of capture of: A, Valenciennellus tripunctulatust, Dannphos oculatus. B, Vinoiguerria
nimbaria, Vinoiguerria lucetia, Vinoiguerria poweriae. C, Ichthyococcus elongatus, Ichthyococcus irregularis.
D, Stomias atriventer, Stomias sp., Chauliodus macmini.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

649

123.50. B6203, (7) 83.5-214 mm.; 137.35. B6212, (1) 49
mm.; 137.50, B6203, (2) 127-178 mm.

This species was listed as a subspecies of Stomias
boa (Risso) by Ege (1934:23) but is now gen-
erally regarded as a distinct species. In a few of
the 78 specimens collected during the survey, the
barbel was broken off, but the normal three equal-
sized filaments at the end of the barbel were pres-
ent in the others, except one. On the exceptional
specimen, one of the three filaments was branched
to near its base, giving the superficial appearance
of four filaments at the end of the barbel.

47. Stomias sp.

Figure 15D.
110.35, H6204, (1) 189 mm.

This specimen, occurring within the range of S.
atriventer, represents either a morphological var-
iant or an undescribed species. It differs in a
number of characters from S. atriventer and from
all known species of Stomias in having six equal-
sized filaments, each with a separate base, at the
end of the barbel.

MELANOSTOMIATIDAE

48. Leptostomias sp.
90.200.C6208, (1) 186 mm.

This specimen was taken about 1,000 km. (620
miles) WSW. of Point Conception, Calif. The
number and taxonomic limits of the species of this
genus are uncertain, and this specimen is not spe-
cifically identified, pending needed study of the
genus.

49. Oposfomias mMsuii Imai.

60.80, C6208, (1) 164 mm.; 83.77, C6303, (1) 77 mm.

These specimens, taken about 185 km. (115
miles) west of San Francisco and about 195 km.
( 120 miles) SE. of Point Conception, Calif., are
the first of this species to be reported from waters
off California. The three known species of this
genus, including 0. micripmts (Giinther) and O.
gibsonpaoei Barnard, appear to be valid, but
further comparison is necessary (R. IT. Gibbs,
personal communication) .

50. FlageUostorrdas boureei Zugmayer.

80.80, H6204, ( 1 i 13-1 mm.; 87.80, C6303. I 1 > 186 mm.

These specimens, taken about 200 and 240 km.

( 125 and L50 miles) off Point Concept ion. Calif.,

differ only slightly from the detailed description
of F. boureei from the western Atlantic by Beebe
and Crane (1939 : 179-185). Comparison of other
Atlantic and Pacific specimens indicates that they
are the same species (R. H. Gibbs, personal
communication).

51. M elanostomim valdiviae Brauer.

86.92, C6303, (2) 163-175 mm.

These two specimens taken about 305 km. (190
miles) SSW. of Point Conception, and one speci-
men in the collections of Scripps Institution of
Oceanography collected off San Juan Seamount,
constitute the first records of this species in this
area.

52. Photonectes margarita (Goode and Bean).

Figure 16A.

60.120. B6203, (1) 138 mm. ; 60.160, H6204, (1) 171 mm. ;
60.200, H6204, (2) 118-193 mm.; 80.90, H6204, (1) 135
mm.; 90.160, C6208, (1) 45 mm.; 93.100, C6303, (1) 138
mm.; 100.80, H6204, (1) 50.5 mm.; 100.120, H6204, (1)
91 mm.; 100.140, H6204, (1) 68 mm.

These specimens appear to be this species, re-
described from material from the North Atlantic
by Beebe and Crane (1939: 175-179). The above
listed specimens vary considerably in several
characters, especially barbel structure (at least
some of this variation is ontogenetic). Although
more than one species may be represented, the
variation in barbel structure is thought to be
intraspecific.

53. Tactostoma, macropus Bolin.

Figure 16A.

60.60, H6204, (1) 175 mm.; 60.80, H6204, (1) 85 mm.;
60.80, C6208, (13) 54.5-325 mm.; 60.90, H6204, (3) 143-
234 mm.; 60.90, C620S, (9) 135-247 mm.; 60.100, C6208,
(1) 231 mm.; 60.120, B6203, (1) 232 mm.; 60.120, H6204,

(1) 228 mm.; 66.100, C6208, (1) 200 mm.; 80.55, H6204,

(2) 85.5-233 mm.; 80.60. H6204, (2) 91-231 mm.; 80.60,
C6208, (2) 156-204 mm.; 80.90-5N, B6203, (2) 91-91.5
mm.; 80.130, C6208, (1) 44 mm.; 82.69, C6303, (1) 81
mm.; 83.77, C6303, (4) 63-163 mm.; 84.92, B6303, (21
56-66 mm.; 80.92, C6303, (3) 210-293 mm.; 87.80, C6303.
(1) 320 mm.; 88.105a, B6303, (1) 76 mm.; 90.60. C6208.
( 1 ) 101 mm.

54. Bathophilv-x flem'mgi Aron and McCrery.

Figure 16A.

60.80, C6208, (1) 64 mm.; 60.120, B6203, (1) 65 mm.;
66.100, C6208, (1) 41.5 mm.; 80.60. C6303, (3) 76-85 mm.;
80.90, H6204, (1) 72.5 mm.; 82.68, C«303, (1) 65 mm.;
84.67, C6303, (1) 84 mm.; 86.92, 06303, (1) 131 mm.;
87.200. B6203, (1) 36 mm. ; 88.105b, B6303, (2) 68-82 mm. ;

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Figure 16. — Locations of capture of: A, Photonectes margarita, Tactostoma macropus. Bathophilus flemingi.
B, Idiacanthus antrostomus, Borostomias panamensis, Aristostomias scintillans. C, Hierops crockeri,
Electrona rissoi. D, Hygophum sp., Tarletonbeania crenularis.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

651

90.140, H6204, (1) 56.5 mm. ; 90.160, H6204, (1) 33 mm. ;
97.40, C6303, (1) 97 mm.; 97.65, C6303, (4) 75-120 mm.;
100.65, C6303, (1) 70 mm.; 100.120, H6204, (1) 62 mm.;
100.140, H6204, (1) 67 mm.

B. flemingi was described as a new species
from the Eastern North Pacific (Aron and Mc-
Crery, 1958 :181) , although it differed only slightly
from the inadequately described B. indicas Brauer
from the Indian Ocean. Recent evidence indicates
that the two species may be synonymous (R. H.
Gibbs, personal communication). We found a
range in pelvic fin rays of 2 + 2 to 2 + 5 in several
specimens counted.

55. Melanostomiatidae, unidentified.
60.180, H6204, (4) 18-30 mm.

These larval specimens have not been identified.

IDIACANTHIDAE

56. Idiacanthus antrostomus Gilbert.

Figure 16B.

60.80, H6204, (5) 53-118 mm.; 60.80, C6208, (1) 216
mm.; 60.90, H6204, (1).207 mm.; 60.90, C6208, (1) 154
mm.; 60.100, H6204, (4) 65-79 mm.; 60.100, C6208, (1)
149 mm. ; 60.120, B6203, (3) 168-269 mm. ; 60.160, B6203.
(1) 160 mm.; 60.180, H6204, (3) 62-124 mm.; 70.80b,
B6203, (2) 100-137 mm.; 70.80-5N, B6203, (1) 121 mm.;
73.200, B6203, (1) dis. ; 80.55, H6204, (1) 135 mm.; 80.70,
H6204, (1) 67 mm. (larva) ; 80.100, B6203, (1) 241 mm.:
82.69, 06303, (2) 99-252 mm.; 83.77, C6303, (16) 64-348
mm.; 84.70, C6303, (1) 150 mm.; 84.92, B6303, (1) 115
mm.; 86.92, C6303, (17) 61-371 mm.; 87.80, O6303, (4)
66-266 mm. ; 87.90, C6303, (4) 123-260 mm. ; 88.105a,
B6303, (1) 344 mm ; 90.48a, H6105, (2) 69-333 mm. ; 90.60,
H6204, (1) 73 mm.; 90.110, C6303, (4) 236-300 mm.;
90.120, H6204, (2) dis., 70 mm. ; 90.140, H6204, (1) 95 mm. ;
90.140, C6208, (2) 58-84 mm. ; 90.150, C6208, (1) 125 mm. ;
90.160, H6204, (1) 65 mm.; 90.160, C6208, (1) 73 mm.;
90.180, H6204, (1) 104 mm.; 90.200, H6204, (1) 42 mm.;
93.100, C6303, (4) 60-342 mm.; 97.40, C6303, (10) 66-320
mm. ; 97.65, O6303, ( 1 ) 210 mm. ; 100.60, H6204, ( 1 ) 249
mm.; 100.65, O6303, (8) 60.5-274 mm.; 100.80, H6204, (2)
dis., 59 mm.; 100.90, H6204, (1) 233 mm.; 103.50, C6303,
(1) 259 mm.; 108.63, C6303, (9) 134-343 mm.; 110.46,
C6303, (3) 209-348 mm.; 110.35, C6303, (8) 156-212 mm.;
110.120, H6204, (1) 98 mm.; 110.160, H6204, (2) 77-115
mm.; 120.80, H6204, (1) 292 mm.; 123.45, B6212, (1) 144
mm. ; 123.50, B6203, (7) 178-292 mm.

This is probably the only species of this genus
that occurs in the eastern Pacific ; as /. panamensis
Regan and Trewavas, described from the Gulf of
Panama, may lie a junior synonym of /. antrosto-
mus (R. II. Gibbs, personal communication). An
adult male of 70 mm. SL from station 60.80,
II('>204 is larger than maximum sizes of males re-

ported as 44 mm. (adult) and 48 mm. (post larva)
by Beebe (1934:234-236). This was the most
abundant and ubiquitous of the 12 species of the
suborder Stomiatoidei taken on the survey.

ASTRONESTHIDAE

57. Borostoniias pcmam-ensis Regan and Tre-
wavas.

Figure 16B.

80.90, H6204, (1) 244 mm.; 84.70, O6303, (1) 195 mm.;
86.92, C6303, (4) 85-270 mm. ; 90.45, H6105, (1) 218 mm. ;
90.48a, H6105, (1) 111 mm.; 120.90, H6204, (1) 186 mm.

B. macristius and B. panamensis, both described
as new species from the Gulf of Panama by Regan
and Trewavas (1929: 26-27), are synonymous (R.
H. Gibbs, personal communication). According
to specimens taken by this survey and in the col-
lections of Scripps Institution of Oceanography,
B. panamensis ranges at least from the Gulf of
Panama to SSE. of Point Conception, Calif.

CHAULIODONTIDAE

58. Chauliodus macouni Bean.

Figures 15D and 17.

60.60, H6204, (5) 27.5-184 mm.; 60.80, H6204, (1) 39
mm. ; 60.80, C6208, ( 1 ) 120 mm. ; 60.90, C6208, ( 1 ) 68 mm. ;
60.100, H6204, (2) 36-53 mm.; 60.140, H6204, (1) 36 mm.;
80.55, H6204, (3) 32-127 mm.; 80.70, H6204, (1) 26 mm.;
80.70, O6208, (1) dis.; 80.90, H6204, (2) 35.5-36 mm.;
80.100, H6204, (1) 31 mm.; 83.77, O6303, (3) 32-36 mm.;
83.90, O6303, (4) 51-64 mm.; 84.67, C6303, (1) 32.5 mm.;
84.70, O6803, (3) 33-198 mm.; 86.92, O6303, (5) 162-213
mm.; 87.80, C6303, (7) 169-204 mm.; 87.90, C6303, (5)
184-207 mm.; 90.60, H6204, (1) 40 mm.; 90.110, C6303,
(2) 162-171 mm.

The genus Chauliodus has been revised by Re-
gan and Trewavas (1929), Ege (1948), and Mor-
row (1961). Only two species of Chauliodus are
known in the eastern Pacific. C. barbatus Garman
ranges from Peru (Morrow, 1961 : 270) northward
to about 1,770 km. (1,100 miles) SE. of southern
Baja California (lat. 13°01' N., long 127°11' W.,
SIO 60-215 ) . C. macouni ranges from Japan, the
southern part of the Bering Sea, and through the
Gulf of Alaska (Morrow, 1961:275-276) south-
ward to the offshore waters of northern Baja
California (station 90.110, C6303). With one
.exception, all evidence points to a geographic
separation of these two species, about 1,770 km.
(1,100 miles) separating their known ranges.

The one exception is a single specimen recorded
by Ege (1948: 108) as C. macouni from lat. 0°18'

652

U.S. FISH AND WILDLIFE SERVICE

S., long. 99°07' W., near the Galapagos Island.
Ege also reported three specimens of C. barbatus
from the same station (3558). Morrow (1961:
256), on the basis of a partial reexamination of
the excepted specimen, stated that, "the Dana spe-
cimen of C. macouni does not appear to have been
mis-identified." Yet nowhere is this specimen so
adequately described, or compared with specimens
from the usual range of O. macouni, that it can
confidently be considered to be G. macouni, in
view of the known occurrence of all other
specimens of C. macouni.

Kegan and Trewavas (1929:32 and 34) stated
that in C. sloani Bloch and Schneider and in C.
danae Regan and Trewavas the proportion of the
eye diameter into the length of the lower jaw is
"larger in male than female." We have deter-
mined that external morphological sexual di-
morphism exists in C. macouni. Of 20 of the
larger specimens taken on cruise C6303 (stations
84.70, 86.92787.80, 89.90, and 90.110), 8 are fe-
males with large, ovarian eggs, ranging from 183-
207 mm. SL (mean size 197), and 12 are males,
162-202 mm. (mean 177). The males have larger
eyes than the females (eye into head 3.3 to 3.8 in
the males, 4.0 to 4.6 in the females). One of the
most pronounced differences between the sexes is
the relative size and shape of the postocular organ.
Morrow (1961:273) found that in C. macouni the

postocular organ was generally elongate and tri-
angular; the exposed luminous portion was trian-
gular or at least, pointed behind, while in other
species of Chm/Iiodus the postocular photophore
was round or nearly so. His characterization is
descriptive of the postocular organ of male speci-
mens of C. macouni, especially of the exposed
luminous portion, but in the females the organ is
different and more variable than in the males.
The organ is always smaller in the adult females.
In some females the exposed luminous portion is
reduced to a small rounded area, less than one-
quarter of the area of that in the adult males; in
others it is elongated, probably owing to a dif-
ferential contraction following preservation of
the surrounding tissue (fig. 17).

MALACOSTEIDAE

59. Aristostomias scintilla/as Gilbert.

Figures 16B and 18.

60.60, H6204, (1) 56 mm. ; 60.80, C6208, (8) 73-214 mm. ;
60.90, C6208, (2) 62-168 mm.; 60.120, H6204, (1) 189
mm.; 60.180, H6204, (1) 55.5 mm.; 70.80b, B6203, (4)
52-64 mm. ; 70.80-5N, B6203, (6) 55-70 mm. ; 80.90, B6203,
(1) 78.5 mm.; 80.90-5N, B6203, (2) 64-67 mm.; 83.77,
C6303. (1) 92 mm.; 86.92, C6303, (1) 54 mm.; 88.105a,
B6303, (1) 58 mm.; 90.70, C6208, (1) 148 mm.; 90.80,
O6208, (1) 51.5 mm. ; 97.40, C6303, (4) 44-140 mm. ; 97.50,
B6203, (2) 82-129 mm.; 100.40, H6204, (1) 114 mm.;
108.63, C6303, (2) 46-109 mm.; 110.40, H6204, (1) 123
mm. ; 120.80, H6204, (1) 101 mm.

?X2.4
l97mm.SL

?X2 8

187mm.

$ X3
202mm.

Figure 17.— Chaiiliodus macouni, postocular organs, showing the typical triangular shape in juveniles and
adult males (right) and.the variable and frequently elongated shape in adult females (left and middle).

PELAGIC FISHES, CALIFORNIA CURRENT AREA

6S."

Figure 18. — AristostortAas scintillans, adult, ca. 280 mm. SL, station 20.40, B50O3.

BATHYLACONIDAE

60. Bathylaco nigricans Goode and Bean.

Figure 19.

86.92, 06303, (1) 244 mm.

The four previously known specimens of this
rare isospondylid (including Macromastax gym-
mis Beebe) were compared by Maul (1059:1-8).
G. E. Maul has lent us another specimen taken off
Madeira. Of the six specimens known to us, four
are from the North Atlantic, and the other Eastern
Pacific specimen is from off Colombia. The two
Pacific specimens differ slightly from the Atlantic
specimens, but all appear to be conspecific. The
specimen taken with the Cobb trawl from about
305 km. (190 miles) SSW. off Point Conception,
Calif., is the largest. known.

GIGANTUROIDEA
GIGANTURIDAE

61. Bathyleptus lisae Walters.

Figures 20 and 25C.
86.92, 0)303, (1) 182 mm.

This is one of the larger and better preserved'
specimens of this species that has been taken (V.
Walters, personal communication). Alive when
it came on deck in the trawl, it bit the junior au-
thor on the finger. Despite a number of trench-
ant morphological differences (that may have an
ontogenetic basis), there are certain similarities
between this species and Bosaura rotunda Tucker
that suggest that they may have at least an intra-
subordinal relationship.

LYOMERI
MONOGNATHIDAE

62. Monognathus sp.
60.140, H6204, (1) 51.5 mm.

This specimen, from about 630 km. (390 miles)
WSW. of San Francisco, Calif., is probably one of
the largest specimens of this little known group to
be recorded; the intrageneric relationships are un-
certain, and this specimen is therefore best not
identified to species (G. L. Orton and R. H. Rosen-
blatt, personal communications).

654

Figure 19. — Bathylaco nigricans, 244 mm. SL, station 86.92, C6303.

U.S. FISH AND WILDLIFE SERVICE

Figube 20.—Bathyleptus lisae (head and lateral views), 182 mm. SL, station 86.92, C6303.

CETUNCULI
CETOMIMIDAE

63. Ditrapichthys sp.

90.200, H6204, (1) 38.5 mm.

This specimen, from about 1,000 km. (620 miles)
WSW. off Point Conception, Calif., is identified
as an undescribed species of Ditroplchthys by
R. R. Rofen (personal communication), who is
preparing a detailed description for publication.

INIOMI

64.

NEOSCOPELIDAE

Scopelengys tristis Alcock.

86.92, C6303, (1) 182 mm.; 90.45a, H6105, (2) 115-143
mm. ; 120.50, H6204, (1) 103 mm.

These specimens were taken about 305 km. (190
miles) SE. of Point Conception, about 95 km. (60
miles) SE. of San Pedro, Calif., and about 70 km.
(45 miles) W. of Punta Eugenia, Baja California.

MYCTOPHIDAE

65. Hierops crockeri (Bolin).

Figure 16C.

60.60, H6204, (1) 29 mm.; 60.70, H6204, (11) 24-35
mm.; 60.70, C6208, (7) 30-36.5 mm.; 60.80, H6204, (8)
22-39 mm.; 60.80, C6208, (2) 35-36 mm.; 60.90, H6204,
(16) 15-40 mm.; 60.100, H6204, (3) 23-27 mm.; 60.100,
C6208, (1) 38 mm.; 60.120. B6203, (4) 22-38 mm.; 60.120,
H6204, (5) 34-38 mm.; 60.140, H6204, (3) 21.5-37 mm.;
60.160, H6204, (4) 34-39 mm.; 60.180, H6204,(l) 24mm.;
60.200, B6203, (1) 30 mm.; 60.200, H6204, (1) 22 mm.;
70.60, C6208, (2) 22-37 mm.; 70.100, C6208, . (2) 36-39
mm.; 80.60, C6208, (2) 23.5-38 mm.; 80.70, B6203, (1) 27
mm.; 80.70, H8204, (3) 10-27 mm.; 80.70, C6208, (1) 19
mm.; 80.75, B6303, (1) 15.3 mm.; 80.80, H6204, (6) 26-42
mm.; 80.100, H6204, (2) 15-16 mm.; 80.140, C6208, (4)
27-46 mm.; 80.150, C6208, (6) 30-52 mm.; 80.170, C6208,
(2) 39-45 mm.; 80.180, C6208, (2) 39 mm.; 80.190,
06208, (1) 24 mm.; 80.200, 06208, (1) 45 mm.; 83.77,
C6303, (26) 25-36 mm.; 83.90, C6303, (79) 25-39 mm.;
84.67, C6303, (11) 15-36 mm.; 84.68, O6303, (6) 26-35.5
mm.; 86.92, C6303, (4) 27.8-34.5 mm.; 87.80, O6303, (2)
19-28 mm. ; 90.45, H6204, (1) 35.5 mm. ; 90.48a, H6105, (1)
18.5 mm.; 90.48b, H6105, (5) 12.5-14 mm.; 90.60, C6208,
(2) 26-28 mm.; 90.70, H6204, (2) 35-42 mm.; 90.100.
C6208, (2) 19-23.5 mm.; 90.140, O6208, (2) 20-46 mm.;

PELAGIC FISHES, CALIFORNIA CURRENT AREA

655

90.160, C6208, (3) 31-40 mm.; 90.180, C6208, (3) 34-43
mm.; 90.200, C6208, (3) 33-40 mm.; 93.31, C6303, (1)
18.5 mm.; 94.32a, B6204, (1) 26 mm.; 97.40, C6303, (2)
17.5-21 mm. ; 97.50, B6203, (2) 29-dis., mm. ; 97.65, C6303,
(4) 31-45 mm.; 100.60, H6204, (1) 25 mm.; 100.65, 06303,
(6) 26.5-32.5 mm.; 100.80, H6204, (1) 17.5 mm.; 100.90,
H6204, (1) 27.5 mm. ; 100.120, H6204, (1) 49 mm. ; 100.160,
H6204, (1) 45 mm.; 103.50, C6303, (4) 20-23 mm.; 108.63,
C6303, (2) 23^3.5 mm.; 110.100, H6204, (1) 15 mm.;
110.140, H6204, (2) 31^4 mm.; 110.160, H6204, (1)
45 mm.; 120.60. H6204, (5) 18.5-26 mm.; 120.70, H6204,
(1) 43 mm. ; 120.80, H6204, (12) 20-46 mm. ; 120.90, M6204,
(3) 29-32 mm.

66. Electrona rissoi (Cocco).

Figure 16C.

80.150, C6208, (1) 30 mm.; 84.92, B6303, (1) 43.5 mm.;
90.100, C6208, (1) 58.5 mm.; 100.65, C6303, (3) 44.5-45.5
mm.; 110.140, H6204, (1) 48 mm.

67. Hygophum sp.

Figure 16D.

60.180, H6204, (1) 43 mm.; 60.200a, B6203, (5) 33-44
mm.; 73.200, B6203, (1) 45 mm.; 80.160, C6208, (246) 19-
52.5 mm.; 80.170, C6208, (11) 30-47 mm.; 80.190, C6208,
(28) 43-52 mm.; 80.200, C6208, (8) 39-53 mm.; 83.77,
C6303. (1) 34 mm.; 86.92, C6303, (1) 36 mm.; 90.80,
C6208, (3) 41^4 mm.; 90.90, C6303, (2) 37.5-39.5 mm.;
90.100, C6208, (2) 42 mm.; 90.110, B6203, (1) 42 mm.;
90.120, C6208, (86) 32-51 mm. ; 90.140, C6208, (1) 40 mm. ;
90.150, C6208, (40) 35-49 mm.; 90.160, H6204, (1) 26
mm. ; 90.160, C6208, (10) 33.5-52 mm. ; 90.190, C6208, (26)
41-55 mm. ; 90.200, H6204, (3) 16-32 mm. ; 92.115, B6303,
(6) 24.5-40 mm.; 100.65, C6303, (1) 21.5 mm.; 100.100,
H6204, (2) 37-13 mm.; 100.140, H6204, (3) 27-43 mm.;
100.160, H6204, (1) 13 mm.; 120.80, H6204, (1) 59 mm.;
123.45, B6212, (1) 45 mm. ; 127.45, B6212, (1) 31.5 mm.

Taxonomic differentiation of the species in this
genus is not definitive or convincing. Fraser-
Brunner (1949:1050) synonymized H. atratum
(Garman) with 77. reinhardti (Liitken). There
are indications, from other studies, that these two
species are distinct (E. H. Ahlstrom, personal
communication). The above specimens appear to
represent either one or both of the cited nominal
species.

68. Benthosemasuborbitale (Gilbert).
90.160, H6204, (1) 31 mm.

This specimen was taken about 740 km. (460
miles) SK. of Point Conception, Calif.

69. Diogenichthys atlanticus (Tuning).

Figure 21A.

60.80, H6204, (1) 19 mm.; 60.160, B6203, (2) 27 mm.;
60.180, H6204, (6) 15-24 mm. ; 60.200a, B6203, (3) 19-26

mm.; 60.200b, B6203, (4) 19.5-23.5 mm.; 70.80b, B6203,
(1) 20 mm.; 70.80-5N, B6203, (8) 15-25 mm.; 70.200,
H6204, (6) 9-22 mm.; 73.200, B6203, (2) 23-26 mm.;
80.80, C6208, (1) 18 mm.; 80.90, B6203, (1) 23 mm.;
80.90-5N, B6203, (55) 18-25 mm.; 80.90, H6204, (4) 13-
22 mm.; 80.160, C6208, (7) all ca. 16 mm.; 80.190, C6208,

(4) 16.5-20.5 mm.; 84.92, 06303, (1) 22.5 mm.; 90.48a,
H6105, (1) 23 mm.; 90.80, C6208, (5) 20-23 mm.;
90.110, C6303, (3) 21-23.5 mm.; 90.120, H6204, (2) 22
mm.; 90.150, C6208, (1) 23 mm.; 90.160, H6204, (3) all
15 mm.; 90.190, C6208, (1) 20 mm.; 90.200, H6204, (5)
12-16.5 mm.; 100.60, H6204, (2) 22.5-25 mm.; 100.65,
C6303, (4) 19.6-23.6 mm.; 100.80, H6204, (3) all 20 mm.;
100.100, H6204, (4) 22-24.5 mm.; 100.140, H6204
(10) 15-23 mm.; 100.160, H6204, (3) all 13mm.; 110.120,
H6204, (1) 16 mm.; 110.160, H6204, (1) 14.5 mm.

The records of capture shown on the chart sug-
gest that D. atlanticus is a northern species in this
area and D. laternatus is a southern species.
Records from other collections show that in waters
farther offshore than sampled by the survey, the
distribution of D. atlanticus extends southward at
leasttolat.20°N.

70. Diogenichthys laternatus (Garman).

Figure 21A.

120.70, H6204, (3) 23.5-24 mm.; 120.80, H6204, (2)
22.5-25 mm.; 120.90, H6204, (6) 22-25 mm.; 127.45,
B6212, (1) 14 mm.; 130.40, B6212, (5) 16-25 mm. ; 133.35,
B6212, (1) 18.5 mm.; 137.35, B6212, (2) 13-18 mm.;
137.50, B6203, (6) 14.5-26 mm.; 140.35, B6212, (16)
12.1-24 mm.

71. Symbolophorus calif orniense (Eigenmann
and Eigenmann) .

Figure 21B.

60.80, C6208, (4) 60-95 mm.; 60.120, B6203, (4) 29-90
mm.; 60.160, B6203, (1) 32 mm.; 60.160, H6204, (1) 95
mm,; 66.100, C6208, (12) 48-71 mm.; 70.60, C6208, (4)
55-74 mm. ; 70.80-5N, B6203, (9) 45-67 mm. ; 70.80, C6208,
(167) 39-91 mm. ; 70.100, C6208, (1) 70 mm. ; 80.52, C6208.

(1) 75 mm.; 80.55, H6204, (1) 90 mm.; 80.60, H6204, (1)
73 mm.; 80.60, C6208, (7) 71-86 mm.; 80.65, B6303, (12)
42-94 mm. ; 80.70, C6208, (2) 78-81 mm. ; 80.75, B6203, (6)
27-59 mm.; 80.80, H6204, (2) 52-67 mm.; 80.80, C6208,
(6) 53-73 mm.; 80.90, B6203, (4) 43-76 mm.; 80.90-5N,
B6203, (5) 25-59 mm.; 80.90, H6204, (4) 32-67 mm.;
80.100, B6203, (34) 44-94 mm.; 80.200, C6208, (1) 30.5
mm.; 82.69, C6303, (24) 37.5-90 mm.; S3.77, C6303, (124)
32.5-85 mm. ; 83.70b, B6303, (16) 51-95 mm. ; 83.90, C6303,

(2) 56-66 mm.; 83.70, C6303, (7) 53-70.5 mm.; 84.67,
C6303, (3) 56.5-65.5 mm. ; 84.92, B6303, (10) 39.5-90 mm. ;
84.70, C6303, (28) 48-75 mm.; 86.92, C6303, (1) 57 mm.;
87.80, C6303, (2) 52.5-55.5 mm.; 87.90, C6303, (5) 46.5-
64.5 mm.; 90.48a, H6105, (3) 57-77 mm.; 90.60, H6204,
(1) 65 mm.; 90.70, C6208, (2) 66-70 mm.; 90.80, C6208,

(5) 40-63 mm.; 90.90, C6303, (1) 73 mm.; 90.120, C6208,
(5) 28-29.5 mm.; 90.190, C6208, (1) 27 mm.; 91.39a,

656

U.S. FISH AND WILDLIFE SERVICE

C6208, (4) 37.5-67 mm.; 91.39b, C620S, (3) 65-77.5 mm.;
97.40, C6303, (11) 48-86 mm.; 97.50, B6203, (4) 54-70
mm.; 97.65, C6303, (24) 32.5-51.5 mm.; 100.40, H6204,
(1) 51 mm.; 100.60, H6204, (2) 24-60 mm.; 100.65, C6303,
(86) 28-87.5 mm.; 100.90, H6204, (1) 28 mm.; 100.120,
H6204, (1) 24 mm.; 103.50, C6303, (1) 54 mm.; 107.60,
C6303, (21) 47-66 mm.; 108.63, C6303, (6) 49.5-62.5 mm.;
110.50, B6203, (1) 46 mm.

This species has generally been known as Myc-
tophum califormense. It was designated as the
type species of the new genus Symbo/op/wrv.s by
Bolin and Wisner in Bolin (1959 : 11) .

1-2. M yctophum rdtidulum Garman.

Figure 21B.
60.200a, B6203, (1) 65 mm.; 90.150, C6208, (2) 50-68
mm.; 90.200, H6204, (1) 19 mm.; 100.65, C6303, (13) 48-
63 mm.; 108.63, C6303, (1) 70 mm.; 110.120, H6204, (2)
25 mm.; 123.50, B6203, (2) 26-36 mm.

This species was recently synonymized with M.
margaritatum Gilbert, the name by which it has
been more commonly known, and was distin-
guished from M. affirie (Liitken) by Bolin
(1959:14).

73. Gonichthys tenuiculus (Garman).

130.40, B6212. (1) 28 mm.; 137.50, B6203, (1) 44 mm.

These specimens were taken about. 70 km. (45
miles) SW. of Ballenas Bay and about 160 km.
(100 miles) W. of Santa Maria Bay, Baja
California.

74. Tarletonbeania crenularis (Jordan and Gil-
bert) .

Figure 16D.
60.60, H6204. (8) 12-62 mm.; 60.60, C6208, (7) 38-59
mm. ; 60.70, H6204, (6) 22-35 mm. ; 60.70, C6208, (3) 43-64
mm. : 60.80, H6204, (8) 12.5-32 mm. ; 60.80, C6208, (9) 29-
54 mm.; 60.90, H6204, (4) 23-31 mm.; 60.90, C6208, (2)
17-36 mm.; 60.100, H6204, (4) 13-31 mm.; 60.100, C6208,
(3) 15-29 mm.; 60.120, B6203, (2) 26-30 mm.: 60.180,
H6204, (3) all 15 mm. ; 65.54, C6208. (8) 37-74 mm. ; 70.51,
C6208, (1) 44 mm.; 70.60, C6208, (1) 17 mm.; 70.80-5N,
B6203, (1) 24 mm.; 77.51, C6208, (3) 34.5-45 mm.; 80.52,
C6208, (77) 34-80 mm.; 80.55, H6204, (1) 32 mm.; 80.60,
B6203, (1) 31 mm.; 80.60, H6204, (2) 30-31 mm.; 80.60,
C6208, (8) 34-60 mm.; 80.65, B6303, (7) 28-36.5 mm.;
80.70, C6208, (2) 19 mm.; 80.75, B6303, (1) 27 mm.;
80.80, C6208, (1) 26 mm.; 80.90-5N, B6203, (3) 27-29
mm.; 80.90, H6204, (3) 17-34 mm.; 80.100, B6203, (1) 36
mm.; 80.100, H6204, (1) 16.5 mm.; 83.69, C6303, (43)
32.5-68 mm. ; 83.70a, B6303, (2) 23-28 mm. ; 83.70b, B6303,
(3) 30.5-32.5 mm.; 83.77, C6303, (2) 18-50 mm.; 83.90,
C6303. (15) 19.5-30.5 mm.; 84.67, C6303, (29) 37.5-61
mm.; 84.70, C6303, (16) 37.5-66.5 mm.; 84.92, B6303, (3)
14-26 mm. ; 90.35, B6203, ( 1 ) 43 mm. ; 90.45a. H6105, ( 1 )

PELAGIC FISHES, CALIFORNIA CURRENT AREA
795-35S 0—66 10

14.5 mm.; 90.45, H6204, (1) 29 mm.; 90.48a, H6105, (7)
16-32.5 mm.; 90.48b, H6105, (1) 14.5 mm.; 90.60, H6204,
(8) 33-48 mm.; 90.70, C6208, (1) 28 mm.

75. Lobianchia gemellari (Cocco).

Fig 21D.
90.160, C6208, (5) 50-53 mm.; 90.200, C6208, (1) 31
mm.; 100.160, H6204, (1) 57 mm.

This species was listed as Diaphm (Hyperpho-
tops) gemellari (Cocco) by Fraser-Brunner
(1949:1066). It was reestablished as the type
species of the genus Lobianchia. Gatti by Bolin
(1959: 18). Taken some 800 km. (500 miles)
WSW. of San Diego, these records would appear to
approach the limit of its eastward distribution in
this latitude.

76. Diaphus theta Eigenmann and Eigenmann.

Figure 21C.

60.60, H6204, (27) 24-53 mm.; 60.60, C6208, (13) 37-
42 mm.; 60.70, H6204, (251) 28-40 mm.; 60.70, C6208,
(8) 34-45 mm.; 60.80, H6204, (11) 25-71 mm.; 60.80,
C6208, (34) 34-54 mm.; 60.90, H6204, (9) 29-63 mm.;
60.90. C6208, (8) 37-41 mm.; 60.100, H6204, (6) 30-63
mm.; 60.100, C6208, (1) 41 mm.; 60.120, B6203, (5) 32-
66 mm.; 60.120, H6204, (2) 30-47 mm.; 60.160, H6204,
(1) 56 mm.; 70.51, C620S, (12) 37.5-57 mm.; 70.80b,
B6203, (4) 33-64 mm.: 70.80-5N, B6203, (38) 24-41 mm.;
70.80, C620S, (15) 32-48 mm.; 70.90, B6203, (1) 32 mm.;

79.54, B6303, (3) 30-52 mm. ; 80.52, C6208, (2) 36-40 mm. ;

80.55, H6204, (2) 29-31 mm. ; 80.60, B6203, (2) 32-34 mm. ;
80.60, H6204, (5) 25-34 mm.; 80.60, C6208, (16) 33-54
mm.; 80.70, B6203, (1) 26 mm.; 80.70, H6204, (1) 33
mm.; 80.70, C6208, (5) 37-44 mm.; 80.75, B6303, (8) 26-
59 mm.; 80.80, H6204, (5) 27-67 mm.; 80.80, C6208, (22)
15-60 mm.; 80.90, B6203, (1) 55 mm.; 80.90-5N, B6203,
(6) 22-39 mm.; 80.90, H6204, (3) 26-50 mm.; 82.69,
CO303, (15) 26-57.5 mm.; 83.70a, B6303, (17) 29-60 mm. :
83.70b, B6303, (2) 135-53 mm.: 83.77, C6303, (45) 24-51
mm.; 83.90, C6303, (63) 22-56.5 mm.; 83.70, C6303, (11)
27-57.5 mm.; 84.67, C6303, (206) 24-50 mm.; 84.68,
C6303, (70) 26.5-41.5 mm.; 84.70, C6303, (74) 23-50 mm. ;
84.92, B6303, (1) 30 mm.; 87.80, C6303, (1) 26.5 mm.;
88.105b, B6303, (6) 21-24.5 mm.; 90.32, B6203, (16) 24-
34 mm.; 90.32, H6204, (2) 27-31 mm.; 90.45, H6204, (3)
35-53 mm.; 90.47, C6208, (13) 35-40 mm.; 90.48a, H6105,
(3) 34-39 mm.: 93.31, C6303, (5) 21-28.5 mm.; 97.40,
C6303, (6) 23-29 mm.; 97.50, B6203, (2) 26-58 mm.;
97.65, C6303, (1) 29 mm.; 100.65, C6303. (1) 23 mm.;
100.120, H6204, (1) 33 mm.; 100.160, H6204, (1) 30 mm.
(specimen damaged, identification questionable).

77. Diaphus fulgens Brauer.

Figure 20.C.
60.200a. B6203, (1) 36 mm.; 87.200, B6203. (1) 30
mm.; 90.150, C6208, (2) 42 mm.; 90.200, C6208, (1)
38 mm.; 110.160, H6204, (3) 28.5 — 43 mm.

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Figure 21. — Locations of capture of : A, Diogenichthys atlanticus, Diogenichthys latematus. B, Bymbolophorus cali-
forniense, Myotophum nitidulum. C. Diaphus theta, nia/iliiis fulgens, Diaphua protoculus. I). Labianrhia gvmcllari,
Diuphux andersonit, Aethoprora elucens.

658

U.S. FISH AND WILDLIFE SERVICE

These specimens and those of D. protoculus (fol-
lowing) were identified according to Fraser-Brun-
ner ( 1949 : 1075 ) . The differences between the two
forms are slight, however, and D. fulgens may be a
junior synonym of D. protoculus.

78. Diaphus protoculus Gilbert.

Figure 21C.
80.200, C6208, (1) 36.5 mm.; 90.160, C6208, (8) 31.5-43
mm.; 90.180, B6203. (1) 24 mm.; 90.190, C6208, (1) 37
mm.; 90.200, H6204. (1) 27 mm.; 110.140, H6204, (2)
43 mm.

79. Diaphus andersoni Tailing?

Figure 21D.
60.120, B6203, (21) 23-33 mm.; 60.120, H6204, (1) 30
mm.; 60.160, B6203, (1) 35 mm.; 60.180, H6204, (1) 25
mm.; 60.200, H6204, (1) 28 mm.; 73.200, B6203, (2) 25-
28 mm.; 80.190. C6208, (1) 32 mm.; 80.200. C6208, (2)
26-29 mm. ; 87.200, B6203, ( 1 ) 27 mm. ; 90.140, C6208, ( 1 )
27.5 mm.; 90.160, H6204, (1) 27 mm.; 90.160, C6208, (3)
26-30.5 mm. ; 90.180. B6203, (3) 25-27 mm. ; 90.1S0, H6204,
(2) 29 mm.; 100.160, H6204, (3) 26.5-30.5 mm.; 110.140,
H6204, (1) 30 mm.

D. andersoni had previously been recorded only
from the South Pacific. The above specimens are
obviously closely related to D. andersoni, but cer-
tain slight differences, especially the relative length
of the luminous patch of tissue extending back
from the lateral pectoral photophore (PLO), sug-
gest that they may be distinct (R. L. Wisner, per-
sonal communication). If these differences war-
rant specific distinction of the above specimens
from D. andersoni, then these specimens represent
an undeseribed species.

80. Aethoprora elwcens (Brauer).

Figure 31D.
80.200, C6208, (1) 51mm.

This species was listed as Diaphus (Lamprossa)
elucens Brauer by Fraser-Brunner (1949: 1073).
It was later placed in the genus Aethoprora Goode
and Bean by Bolin (1959:22). This single rec-
ord from about 970 km. (600 miles) off Point Con-
ception undoubtedly represents a rare occurrence
of the species off California.

81. Notolychnusvaldiviae (Brauer).

Figure 22A.

60.180. H6204. (4) 20-24 mm.; 60.200a. B6203. (14) all
ca. 14 mm.; 60.200. H6204, (3) 22-24 mm.; 70.200, H6204,
(11) 17-25 mm.; 73.200, B6203, (67) 14-26 mm.; 80.200,
C6208, (1) 22.5 mm. ; 84.92, B6303, (2) 22-25 mm. ; 87.200,
B6203, (9) 18-26 mm.; 90.120, C6208, (2) 14.5-18.5 mm.;

90.160, H6204, (9) 18-25 mm.; 90.1SO, H6204, (2) 24-26
mm.; 90.200, H6204, (7) 20-24 mm.; 100.60, H6204, (1)
19 mm.; 100.80, H6204, (2) 23 mm.; 100.100, H6204,
(1) 22 mm.; 100.140, H6204, (20) 19.5-24.5 mm.; 100.160,
H6204, (24) 13-24 mm.; 110.160, H6204, (16) 20-30 mm.

82. Lampadena urophaos Paxton.

Figure 22B.
60.160. H6204, (1) 57 mm.; 86.92, C6303, (1) 50 mm.;
100.40, H6204, (1) 103 mm.

These specimens extend northward and seaward,
the known range of this species recently described
by Paxton (1963:29-33).

83. Taaningichthys bathyphilus (Taning).

Figure 22B.
120.70, H6204, (1) 66.5 mm.

This species, previously known as Lampadena
bathyphila, was designated as the type species of
the new genus Taaningichthys by Bolin (1959:
25).

84. Taaningichthys minimus (Taning).

Figure 22B.
80.200, C6208, (1) 52 mm.; 100.140, H6204, (1) 55 mm.

This species, formerly known as Lampadena
minima, was one of the two species included in
the new genus Taaningichthys described by Bolin
(1959: 25). T. ■minimus was described from the
North Atlantic Ocean — we know of no previous
records of it from the Pacific Ocean.

85. Taaningichthys spp.

Figure 22B.
60.60, H6204, (1) 90 mm.; 60.140, H6204, (2) 80-85
mm.; 80.90, H6204, (1) 30 mm.; 100.60, H6204, (1) 70
mm.; 100.80, H6204, (1) 83 mm.; 110.160, H6204, (1) 51
mm.

The above six station records include more than
one species of Taaningichthys. They are not, so
far as known, T. bathyphilus or T. minimus, the
only two species ascribed to this genus by Bolin
(1959:25). Some of the above specimens lack
photophores, and all of them may represent un-
deseribed species.

86. Stenobrachim leucopsarus (Eigenmann and
Eigenmann).

Figure 22A.

60.60, H6204, (95) 19-70 mm.; 60.70, H6204, (4) 20-26
mm. ; 60.80, H6204, (20) 15.5-82 mm. ; 60.80, C6208, (26)
25-63 mm.; 60.90. H6204, (10) 29-56 mm.; 60.90, C6208,
(1) 51 mm. ; 60.100, H6204, (1) 35 mm. ; 60.120, H6204, (1)
38 mm.; 70.80b, B6203, (4) 33-64 mm.; 70.80-5N, B6203,
(57) 26-60 mm. ; 77.51, C6208, (6) 50-66 mm. ; 79.54, B6303,

PELAGIC FISHES, CALIFORNIA CURRENT AREA

659

(8) 35.5-58 mm.; 80.52, C6208, (3) 49-52 mm.; 80.55,
H6204, (117) 32-82 mm.; 80.60. B6203, (13) 33-57 mm.;
80.60, H6204, (154) 30-75 mm.; 80.60, C6208, (735) 22.5-
78 mm.; 80.65, B6303, (4) 28-69 mm.; 80.70, H6204, (3)
36-71 mm.; 80.70, C6208, (24) 43-70 mm.; 80.75, B6303,
(4) 34.5-71.5 mm.; 80.80, H6204, (8) 34-78 mm.; 80.90,
B6203, (5) 38-60 mm.; 80.90-5N, B6203, (11) 31-51 mm.;
80.90, H6204, (4) 17-35 mm.; 80.100, B6203, (2) 32-36
mm.; 82.69, C6303. (38) 29-68.5 mm.; 83.70, C6303, (44)
49-72 mm.; 83.70a, B6303, (4) 57-59 mm.; 83.70b, B6303,
(1) 29 mm.; 83.77, 05303, (29) 31-73 mm.; 83.90, O6303,
(3) 38-62.5 mm.; 84.67, C6303, (43) 44-7i mm.; 84.70,
C6303, (143) 31-74 mm.; 84.92, B6303, (4) 55-70 mm.;
90.32, B6203, (27) 29-72 mm.; 90.32, H6204, (21) 32-80
mm.; 90.45, H6105, (51) 37-78 mm.; 90.47, C6208, (74)
44-72 mm.; 90.48a, H6105, (135) 10.5-74 mm.; 90.48b,
H6105. (4) 10-17.5 mm., 90.60, H6204, (257) 30-65 mm.;
90.70, H6204, (1) 38 mm.; 90.70, C6208, (10) 42-63 mm.;
93.29, O6208, (1) adult; 94.32a, B6204, (4) 36-69 mm.;
94.32b. B6204, (7) 52-67 mm.; 95.31a, B6204, (8) 33^49
mm.; 95.31b, B6204. (11) 35-66 mm.; 95.31e, B6204, (20)
34-59 mm.; 97.40, C6303, (67) 32-76 mm.; 97.50, B6203,

(1) 51 mm.; 97.65, C6303, (3) 50-63 mm.; 100.40, H6204,
(12) 39-72 mm.; 100.65, C6303, (12) 49.5-62 mm.

This species has usually been recorded as Lam-
panyctus leucopsarus, although it was recorded as
Lampanyctus (StenobracMus) leucopsarus by
Fraser-Brunner (1949:1082). StenobracMus is
distinctive enough to warrant full generic status
(R. L. Wisner, personal communication).

87. Lampanyctus (Triphoturus) mexicanus
(Gilbert").

Figure 22C.

60.60. H6204, (1) 35 mm. ; 80.55, H6204, (2) 34-55 mm. ;
80.60, H6204, (3) 35-47 mm.; 80.65, B6303. (1) 23 mm:;
80.70. H6204. ( 4 ) 28-57 mm. ; 80.75, B6303. ( 1 ) 24.5 mm. :
80.80, H6204, (3) 27-62 mm.; 80.80, C6208, (2) 37-43
mm.; 80.90-5N, B6203. (13) 26-58 mm.; 80.90, H6204,
(12) 24-60 mm.; 80.100. B6203, (1) 4.8 mm.; 82.69, C6303.
(29) 22-61.5 mm.; 83.70a, B6303, (1) 23.5 mm.; 83.70b,
B6303, (3) 28-29 mm.; 83.77, C6303, (84) 24-67.5 mm.;
84.67, 06303. (1) 44 mm.; 84.92, B6303, (1) 50 mm.;
86.92, C6303, (93) 44-67 mm.; 87.80, C6303, (58) 38.5-66.5
mm.; 87.90, C6303. (1) 43.5 mm.; 90.32, B6203, (10) 32-
58 mm. ; 90.32, HG204, ( 11 ) 28-49 mm. ; 90.45, H6105, (35)
29-54 mm.; 90.45, H6204, (1) 29 mm.; 90.47, C6208, (3)
42-60 mm.; 90.48a, H6105, (79) 14-66 mm.; 90.60. B6203,
i 1 i 24 mm. ; 90.60, H6204, (10) 30-59 mm.; 90.70, C6208.

(2) 47-54 mm.; !»0.120, H6204, (1) 27 mm.; 90.160, H6204,
(li 56 mm.; 91.39a, C6208, (1) 43 mm.; 93.100, C6303,
(3000) 25 7(i mm.; 94.32a, B6204, (14) 30-57 mm. ; 95.31b,
B6204, (2) 31-34 mm.; 97.40, C6303. (715) 23-66 mm.:
97.50, B6203, (5) 29-57 mm.; 97.65, C6303, (20) 26-66
mm.; 100.40, H6204, (20) 38-65 mm. ; 100.40, C6303, (2)
54 mm.; 100.50, H6204, (1) 60 mm.; 100.60, H6204.
(22) 30-66 mm.; 100.65, ('6303, (461) 22.5-67 mm.; 100.80,
H6204, (3) 27 (Ml mm.; 100.90, H6204, (17) 52-71 mm.;

100.100, H6204, (7) 23-63 mm.; 100.120, H6204, (1) 58
mm.; 100.140, H6204, (5) 31.5-58.5 mm.; 107.60, C6303,

(1) 37 mm.; 108.63, C6303, (1857) 24-72 mm.; 110.35,
H6204, (11) 35-66 mm.: 110.40, H6204, (83) 28.5-70
mm.; 110.46, C6303, (2) 47.5 mm.; 110.50, B6203, (22)
23-69 mm.; 110.120, H6204, (13) 24-67 mm.; 110.160,
H6204, (1) 28 mm.: 111.36a, C6303, (ca. 600) adults and
juveniles; 111.37b, C6303, (101) 32-62 mm.; 113.34a,
C6303, (29) 25-60 mm. ; 118.43, B6212, (613) 16.5-43 mm. ;
120.45, H6204, (307) 22-69 mm.; 120.45, B6212, (22) 16.5-
56 mm.; 120.50, H6204, (299) 26-68 mm.; 120.60, H6204,

(2) 23.5-24 mm. ; 120.70, H6204, (33) 25.5-64 mm. ; 120.80,
H6204, (S3) 26.5-66 mm. ; 120.90, H6204, (28) 27-65 mm. ;
123.45, B6212, (98) 15.5-56 mm.; 123.50, B6203, (135)
23-70 mm.; 127.45, B6212, (48) 17.5-60.5 mm.; 130.40,
B6212, (40) 18-56.5 mm. ; 133.35, B6212, (20) 17.5-40 mm. :
137.35, B6212, (6) all 20 mm.; 137.50, B6203, (5) 25-59
mm. ; 140.35, B6212, (183) 16.5-53 mm.

88. Lampanyctus (Triphoturus) nlgrescens
Brauer.

Figure 22C.

60.180, H6204, ( 1 ) 25 mm. ; 60.200. H6204, ( 1 ) 28 mm. :
70.200, H6204, (2) 26 mm. and damaged adult; 80.160,
C6208, (3) 30-33 mm.; 87.200, C6208, (2) 32-38 mm.;
90.160, C6208, (1) 31 mm.

89. Lamp •any 'ctus (Triphoturus) microchir
Gilbert.

Figure 22C.
80.200,06208, (1) 35 mm.

90. Lampanyctus ritteri Gilbert.

Figure 22D.

60.60, H6204, (6) 38-84 mm.; 60.80. H6204, (9) 30-83
mm.; 60.80, O6208, (35) 43-88 mm.; 60.90, H6204, (5)
35-9Smm. ; 60.90. 06208, (2) 42-51 mm. ; 60.100, H6204, (6)'
29-67 mm. ; 60.120, B6203, (13) 28-92 mm. ; 60.120, H6204,
(12) 43-115 mm.; 60.140. H6204, (8) 20-105 mm.; 60.160,
H6204, (4) 36-118 mm.: 70.80b, B6203, (7) 39-44 mm.;
70.80-5N, B6203, (120) 28-57 mm.; 73.200, B6203, (1)
25 mm.: 80.55, H6204, (8) 40-104 mm.; 80.60, B6203, (7)
22-64 mm.; 80.60, H6204, (20) 36-105 mm.; 80.60, C6208,
(42) 33-80 mm.; 80.70, H6204, (10) 44-115 mm.: 80.75,
B6303. (8) 34-76.5 mm.: S0.80, H6204, (35) 35-109 mm.;
80.90, B6203, (5) 38-60 mm.: 80.90-5N, B6203, (4) 37-44
mm.; 80.90, H6204, (27) 26-96 mm.; 80.100. B6203, (14)
28-70 mm.; 82.69, 06303, (121) 30-84 mm.; 83.70, C6303,

(3) 49-72.5 mm.; 83.70a, B6303, (5) 43.5-70 mm.; 83.77,
06303, (259) 28.5-90 mm.; 83.90, C6303, (1) 66 mm.:
84.67. 06303, (36) 31-65.5 mm.; 84.70, 06303, (6) 37-95
mm.; 84.92, B6303, (31) 23-93 mm.; 86.92, C6303, (31)
38-110 mm.; 87.80, C6303, (8) 34-78 mm.; 90.32, B6203,
(8) 36-60 mm.; 90.32. H6204. (1) 47 mm.: 90.45a, H6105,
(2) 47-107 mm.: 90.47, C6208, (2) 51-73 mm.; 90.48a,
H6105, (120) 23.5-97 mm.; 90.60, B6203, (2) 48 mm.;
90.60, H6204, (60) 35-106 mm.; 90.70. H6204, (201 39-112
mm.: 90.70, C6208, (14) 27.5-7(1 mm.: 91.39a, C6208, (1)
54 mm.; 93.100. C6303, (8) 82-93 mm.; !M.32a, 156204, (1)
95 mm. ; 94.32b, B6204, (2) 66-82 mm. ; 97.40, 06303, (88)

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Figure 22. — Locations of capture of: A, Notolychnus valdiviae, Stcnobrachius leucopsarus. B, Lampadena
urophaos, Taaningichthys bathyphilus, Taaningiohthy smmimus, Taaningichthys spp, C. Lampanyctus
(Triphotvrus) mexicanus, Lampanyctus (Triphoturus) nigrescens, Lampanyctus (Triphoturus)
microchir. D, Lampanyctus ritteri, Lampanyctus niger.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

661

28-108 mm.; 97.50, B6203, (7) 32-97 mm.; 97.65, C6303,
(2) 46 mm.; 100.40, H6204, (12) 48-97 mm.; 100.60,
H6204, (6) 28-110 mm.; 100.65, C6303, (47) 27.5-99.5
mm.; 100.90, H6204, (1) 107 mm.; 100.100, H6204, (1)
24.5 mm. ; 100.120, H6204; (1) 84 mm. ; 108.63, C6303, (15)
28-99 mm.; 110.35, H6204, (1) 30 mm. ; 110.40, H6204, (3)
88-105 mm. ; 110.50, B6203, (2) 46-90 mm. ; 120.45, H6204,
(2) 35-115 mm.; 123.50, B6203, (1) 27 mm.; 137.50,
B6203, (2) 43 mm.

91. Lampanyctus regalis (Gilbert).

Figure 23A.
60.60, H6204, (3) 57-76 mm.; 60.80, C6208, (1) 64 mm.;
60.90, H6204, (2) 50-58 mm.; 60.100, H6204, (1) 36 mm.:
60.120, B6203, (1) 38 mm.; 60.180, H6204, (2) 24-25 mm.;
70.200, H6204, (1) 4.5 mm. ; 80.55, H6204, (3) 41-53 mm. ;
80.60, B6203, (1) 40 mm.; 80.60, H6204, (2) 42-44 mm.;
80.75, B6303, (2) 27.5-39.5 mm. ; 83.69, C6303, (1) 36 mm. ;
83.77, C6303, (1) 39 mm. ; 84.67, C6203, (1) 43 mm. ; 87.200,
B6203, (2) 34-35 mm.; 90.32, H6204, (1) 43 mm.; 90.45a,
H6105, (2) 48-52 mm.; 90.60, H6203, (1) 35 mm.; 90.160,
H6204, (3) 38-49 mm.; 97.50, B6203, (2) 44 mm.; 100.65,
C6303, (2) 36-48 mm.; 100.120, H6204, (1) 39 mm.

92. Lampanyctus idostigma Parr.

Figure 23A.
120.80, H6204, (1) 44 mm. ; 120.90, H6204, (3) 30-59 mm.

93. Lampanyctus niger Giinther.

Figure 22D.
73.200, B6203, (1) 36 mm.; 80.200, C6208, (1) 42 mm.;
86.92, C6303, (7) 51-88 mm.; 100.65, C6303, (1) 62 mm.;
100.140. H6204, (2) 111 mm.

94. Lampanyctus niger Giinther ?

60.180, H6204, (1) 64 mm. ; 87.80, C6303, (2) 72-89 mm. ;
100.100, H6204, (1) 44.5 mm. ; 100.160, H6204, (1) 102 mm.

These damaged specimens appear to represent
this species, but their identity is uncertain.

95. Lampanyctus steiribecki Bolin.

Figure 23B.

60.140, H6204, (1) 54 mm.; 60.160, H6204, (1) 77 mm.;
60.1S0, H6204, (3) 37.5-47.5 mm.; 60.200a, B6203, (2)
39 mm.;60.200, H6204, (3) 28-112 mm.; 70.200, H6204,
(7) 26-53 mm.; 73.200, B6203, (6) 25-42 mm.; 80.200,
C6208, (1) 40 mm.; 83.77, C6303, (1) 30.5 mm.; 87.80.
C6303, (1) 35.2mm.; 90.160, H6204, (1) 43.5 mm.; 90.160.
C6208, (2) 35-41 mm. ; 90.180, B6203, (1) 39 mm. ; 90.180,
H6204, (12) 35-47 mm.; 90.200, H6204, (3) 28-33 mm.;
100.140, H6204, (3) 25-37 mm.; 110.160, H6204, (6)
23-51 mm.

96. Latm.panyctus tenui formes (Brauer).

Figure 23B.
83.77, C6303, (1) 38 mm. ; 100.65, C6303, (2) 34-35 mm.

97. Lampanyctus parvicauda Parr.

Figure 23B.
137.50, B6203, (1) 60 mm.

This species was distinguished from the closely
related L. omostigma Gilbert by Wisner (1963:
16-23.)

98. Lampanyctus sp. (no pectorals).

Figure 23B.

60.180, H6204, (1) 63 mm.; 60.200, B6203, (3) 30-65
mm.; 60.200, H6204, (3) 56-60 mm.; 70.200, H6204, (2)
23-39 mm.; 73.200, B6203, (3) 57-66 mm.; 80.80, H6204,
(1) 61 mm. ; 80.100, B6203, (1) 62 mm. ; 80.200, C6208, (4)
31.5-62 mm. ; 83.77, C6303, (1) 32 mm. ; 86.92, C6303, (10)
47.5-60 mm.; 87.80, C6303, (1) damaged adult; 90.32,
H6204, (1) 46 mm.; 90.48a, H6105, (1) 30 mm.; 90.70,
C6208, (1) 48 mm.; 90.160, H6204, (4) 26-64 mm.; 90.160,
C6208, (12) 45-58 mm.; 90.180, H6204, (10) 27-68 mm.;
90.200, H6204, (2) 59-63 mm.; 100.60, H6204, (2) 25-32
mm.; 100.90, H6204, (1) 35 mm.; 100.120, H6204, (1) 55
mm.; 100.140, H6204, (7) 25.5-59 mm.; 100.160, H6204,
(4) 49-60 mm. ; 110.120. H6204, (1) 50 mm. ; 120.90, H6204,
(1) 47 mm.

These specimens probably represent an unde-
scribed species. None of them possesses visible
pectoral fins, and cleared and stained specimens
have no pectoral fin ray bases or actinosts and
fewer vertebrae than are usually found in the
genus Lampanyctus. Pattern and numbers of
photophores also reveal certain differences between
this form and other members of the genus. They
are specifically distinct from the pectoral-less Lam-
panyctus achirus described as a new species by
Andriashev (1962:257-259).

99. Lampanyctus sp.

110.160, H6204, (1) 22 mm.

This single specimen, from about 800 km. (500
miles) westward of Punta Eugenia, Baja Califor-
nia, probably represents an undescribed species
(R.L. Wisner, personal comunication).

100. Lampanyctus spp., unidentified.

60.100, H6204, (1) head only; 84.68, C6303, (1) juve-
nile; 84.92, B6303, (2) juvenile and adult; 90.70, H6204,
(3) 52-90 mm. ; 90.160, H6204, (1) 20 mm. ; 90.190, C6208,
(1) 40 mm. ; 90.200, H6204. (2) larva and juvenile; 100.50,
H6204, (1) 67 mm.; 100.160, H6204, (3) juveniles; 110.35,
H6204, (1) 37 mm.; 110.140, H6204, (5) juveniles; 137.50,
B6203, (4) 30-35 mm.

These specimens probably represent several
species, but they are either too damaged or too
immature to allow specific identification without
adequate comparative material.

662

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Figure 23. — Locations of capture of: A, Lampanyctus regalis. Lampanyctus idostigma. B, Lampanyctus sp.
(no pectorals), Lampanyctus stcinbecki, Lampanyctus tenuiformes, Lampanyctus parvicauda. C,
Parvilux ingots, Lepidophanes pyrsobolus. D, Ceratoscopelus townsendi, Xotoscopelus resplendens.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

663

101. Parvikix ingens Hubbs and Wisner.

Figure 23C.

60.80, C6208, (3) 108-128 mm.; 60.90, H6204, (1) 95
mm.; 60.100, H6204, (1) 74 mm.; 60.120, H6204, (2) 56-
96 mm.; 83.77, C6303, (1) 51.5 mm.; 86.92, C6303, (6) 93-
178 mm.; 87.80, C6303, (1) 174 mm.; 90.70, C6208, (2)
134-157 mm.; 90.120, H6204, (1) 121 mm.; 97.40, C6303,

(2) 52 mm.; 97.50, B6203, (2) 74-76 mm.; 100.40,
H6204, (1) 72 mm.; 100.60, H6204, (1) 76 mm.; 100.65,
C6303, (4) 139-192 mm.; 110.46, C6303, (1) 166 mm.

102. Lepidophanes pyrsoboJus (Alcock).

Figure 23C.

60.180, H6204, (1) 25 mm.; 70.200, H6204, (1) 42 mm.;
73.200, B6203, (4) 21-30 mm.; 80.200, C6208, (1) 33.5
mm.; 83.77, C6303, (6) 29.5-42 mm.; 90.70, C6208, (2)
36 mm.; 90.120, H6204, (2) 31-37 mm.; 90.160, H6204,

(3) 22-38 mm.; 90.160, C6208, (8) 29-40 mm.; 90.180,
H6204, (1) 38 mm. ; 90.200, H6204, (2) 30-34 mm. ; 100.65,
C6303, (6) 30.5-45.5 mm.; 100.80, H6204, (1) 30 mm.;
100.100, H6204, (3) 29.5-31.5 mm.; 100.140, H6204, (5)
22.5-46 mm.; 110.120, H6204, (2) 24-28 mm.; 110.160,
H6204, (5) 23-44 mm.; 137.50. B6203, (1) 27 mm.

103. Ceratoscopehis townsendi (Eigenmann and
Eigenmann).

Figure 23D.

60.80, H6204, (3) 33-55 mm.; 60.100, H6204, (6) 35-60
mm.; 60.120, B6203, (2) 40-56 mm.; 60.120, H6204, (1)
43 mm.; 60.140, H6204, (2) 53 mm.; 60.160, H6204, (2)
72-83 mm.; 60.180, H6204, (2) 31-32 mm.; 60.200, B6203,

(1) 25 mm. ; 66.100, C6208, (7) 23-35 mm. ; 70.80b, B6203,

(2) 20-38 mm.; 70.80-5N, B6203, (35) 22-52 mm.; 70.200,
H6204, (3) 13-44 mm.; 73.200, B6203, (1) 52 mm.; 80.70,
H6204, (1) 52 mm.; 80.75, B6303, (1) 52 mm.; 80.80,
H6204, (3) 22-52 mm.; 80.90-5N, B6203, (66) 20-55 mm.;
80.90, H6204, (15) 40-59 mm.; 80.100, B6203, (1) 54 mm.;
80.160, C6208, (1) 22.5 mm.; 80.190, C6208, (1) 24 mm.;
80.200, C6208, (11) 19-56 mm.; 82.69, C6303, (24) 33.5-
57.5 mm.; 83.77, C6303, (716) 33.5-61 mm.; 83.90, C6303,
(142) 33-51 mm.; 84.67, C6303, (11) 40-50 mm.; 84.70,
C6303, (1) 44 mm.; 84.92, B6303, (4) 29.5-57 mm.; 86.92,
C6303, (11) 33.5-52.5 mm. ; 87.80, C6303, (6) 36-47.5 mm. ;
90.48a, H6105, (1) 42 mm.; 90.70, H6204, (2) 45-48 mm.;
90.80, C6208, (5) 23-32 mm. ; 90.110, C6303, (1) 25.5 mm. ;
90.120, H6204, (4) 18-49 mm.; 90.120, C6208, (64) 19-26.5
mm.; 90.150, C6208, (73) 15-27 mm.; 90.160, H6204, (5)
19-50 mm.; 90.160, C6208, (6) 48-53 mm.; 90.180, B6203,
(1) 21 mm. ; 90.180, H6204. (6) 29-57 mm. ; 90.180, C6208.
(1) 21 mm. ; 90.200, H6204, (9) 15-53 mm. ; 91.39a, C6208,

(1) 52 mm.; 92.115, B6303, (1) 24 mm.; 97.40, C6303,
(7) 38-51 mm.; 97.65, C6303, (85) 28.5-44 mm.; 100.60,
H6204, (9) 38-51 mm.; 100.65, C6303, (944) 20-52 mm.;
100.80, H6204, (2) 36-40 mm. ; 100.90. H6204, (1) 38 mm.;
100.100, H6204, (9) 22.5-59 mm.; 100.120, H6204, (3) 47-
50 mm. ; 100.140. H6204. (9) 20-29 mm. ; 100.160, H6204,

(2) 21-39 mm.; 108.63, C6303, (118) 29.5-40.5 mm.;

110.40, H6204, (1) 40 mm.; 110.120, H6204, (3) 24-30
mm.; 110.160, H6204, (13) 17-54 mm.; 120.70, H6204, (8)
30-41 mm. ; 120.80, H6204, (9) 26.5-46 mm. ; 120.90, H6204,
(9) 25-39 mm.; 123.45, B6212, (6) 24-29.5 mm.; 127.45,
B6212, (1) 22.5 mm. ; 133.35, B6212, (1) 20.5 mm. ; 140.35,
B6212, (1) 32.5 mm.

104. Notoscopelus resplendens Richardson.

Figure 23D.

66.100, C6208, (3) 29-37 mm. ; 80.80, H6204, (1) 58 mm. ;
80.160, 06208, (2) 27 mm.; 80.170, C6208, (1) 31 mm.;
80.190, C6208, (3) 27.5-31 mm.; 86.92, C6303, (3) 56.2-60.5
mm.; 90.120, C6208, (15) 26-31 mm.; 90.140, C6208, (1)
27 mm. ; 90.150, C6208, (12) 22.5-32.5 mm. ; 90.160, H6204,

(1) 64 mm.; 90.200, H6204, (1) 15 mm.; 100.65, C6303,
(18) 43-64 mm.; 100.100, H6204, (1) 34.5 mm.; 100.120,
H6204, (1) 70 mm.; 100.160, H6204, (1) 26 mm.; 108.63,
C6303, (2) 44-60 mm. ; 110.120, H6204, (1) 61 mm. ; 120.90,
H6204, (1) 67 mm.

105. Myctophidae, unidentified.

60.55, C6280. (1) discarded at sea ; 70.80-5N, B6203, (1)
adult; 70.200, H6204, (1) juvenile; 80.80, C6303, (2) dis-
carded at sea; 80.90, B6203, (4) adults; 90.140, C6208,

(2) juveniles; 90.150, C6208, (1) adult; 90.160, H6204,
(2) juveniles; 90.200, H6204, (2) larvae, may be Lepido-
phanes pyrosobolus.

These specimens are badly damaged or other-
wise unidentifiable and probably represent several
species.

PARALEPIDIDAE

106. Sudis atrox Rofen.

Figures 24 and 25A.

80.160, C6208, (1) 21.5 mm.

The genus Sudis of the monotypic subfamily
Sudinae was for many years known only from the
eastern Atlantic off Madeira and the Mediter-
ranean as Sudis tiyalina- Rafinesque. The larval
stages of this species were described and illustrated
by Sanzo (1918). A review of the genus Sudis
was presented by Harry (1951 : 33-35). A new
species from the eastern Pacific, Sudis atrox, was
recently described by Rofen (1963: 5, fig.l). S.
atrox was based on a 75-mm. SL holotype and "35
identifiable remains'' taken from stomach contents
of Alepisaurus and Parethunnus sibi at two sta-
tions several hundred kilometers west of Baja
California. Fourteen specimens of S. atrox, 3.4
mm. Notochord Length to 12.5 mm. SL had been
sorted from 13 stations of Norpac Expedition be-
tween Hawaii and the American mainland (E.H.
Ahlstrom, personal communication) .

664

U.S. FISH AND WILDLIFE SERVICE

Figure 24.—Sudis atrox. 21.5 mm. SL station 80.160, C620S.

107. Lestidium ringens (Jordan and Gilbert).

Figure 25A.

60.80, C6208, (1) 60 mm.; 60.120, B6203, (1) 72 mm.;
70.S0, B6203, (1) 39 mm. ; 80.80, H6204, (1) 53 mm. ; 80.90,
H6204, (2) 20-71 mm.; 80.100, H6204, (1) 78 mm.; 90.90,
C6203, (35) 42-64 mm. ; 90.120, H6204, ( 1 ) 28 mm. ; 100.40,
H6204, (1) 150 mm.

The 35 specimens taken in the Cobb pelagic
trawl at station 90.90 indicate that this species
may occur in large schools at least in certain areas.
It has been identified from a large number of rou-
tine CalCOFI plankton-tow stations, but only one
or a few specimens had been taken in a single tow.
Lestidium elongatum Ege is undoubtedly a junior
synonym of this species (E. H. Ahlstrom and
R. R. Rofen, personal communications). The
specimen reported as Macroparalepis sp. by Harry
(1953 : 186, fig. 5) is a young stage of L. ringens.

108. Notohjm rissoi (Bonaparte).

Figure 25A.
70.200, H6204, (1) 59 mm. ; 80.160. C6208, (2) ea. 37-ca.
65 mm.; 80.200, C6208, (1) ca. 30 mm.; 90.120, C6208,
(10) 32-49 mm.

This species has generally been designated under
the name of Notolepis coruscans (Jordan and Gil-
bert) (R. R. Rofen, personal communication).
Our relatively small and mostly damaged speci-
mens have lower numbers of anal fin rays (a max-
imum of 26 or 27) than other eastern Pacific
specimens that have been reported (A. 29 to 33)
(Harry, 1953:210).

109. Macroparalepis macrurus Ege.

Figure 25A.

70.200, H6204, (1) 41.5 mm.; 80.160, C6208, (1) ca. 59
mm.; 80.170, C6208, (1) ca. 73 mm.; 80.180, H6204, (1)
135 mm.; 80.200, C6208, (4) ca. 42-ca. 74 mm.; 90.80,
C6208, (1) ca. 70 mm.; 90.100, C6208, (1) ca. 62 mm.;
90.120, C6208, (13) 67-77 mm.; 90.140, C6208, (1) ca.
72 mm. ; 90.150, C6208, (73) ca. 61-82 mm. ; 90.200, H6204,
(1) ca. 27 mm.

This species is more widespread in the eastern
Pacific, and perhaps more gregarious, than pre-
viously shown. The larvae have been taken in
offshore plankton-net collections, but most catches
had only one or two individuals. Most of the
records reported by Ege (1957:94-95) are of
single specimens ; the maximum at one station was
nine. The 73 specimens taken at station 90.150
in September by the Cobb pelagic trawl indicate
that the species is at times locally abundant.

The above records extend the known range of
the species. Previously Ege (1957:68) had re-
corded it from northeast of the Galapagos Islands.
Harry (1953:231) placed this species in the
genus Stemnosudis Harry, but our specimens,
and apparently those of Ege, possess characters
more like those of Macroparalepis. The 135-mm.
specimen, one of the largest specimens of the species
to be recorded, has the anterior lateral line scales
only slightly higher than long (1.17X) , the nostrils
well in advance of a vertical line through the
posterior end of the maxillary, D. 8, A. 38, verte-
brae 96 total and 33 prehaemal, and the anterior
peritoneal pigment spots coalesced (about 14 were
present) .

SCOPELARCHIDAE
110. Benthalbella dentata (Chapman).

Figure 25B.

83.90, C6303, (1) 43.5 mm.; 88.77, C6303, (1) 42 mm.;
87.80, C6303, (1) 118 mm.; 100.65, C6303, (1) 200 mm.;
108.63, C6303, (1) 167 mm.

Chapman (1939:530) described this species in
the new genus he proposed, Neoscopelarchoi-des.
Marshall (1955:314) used this generic name rather
than Benthalbella. Zugmayer 1911. These two ge-
neric names, however, are synonymous, and under
the current International Rules of Zoological
Nomenclature, Benthalbella has priority (E. H.
Ahlstrom, personal communication).

PELAGIC FISHES, CALIFORNIA CURRENT AREA

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Figure 25.— Locations of capture of: A, Sudix atrox, Lestidium ringenx, Nototcpis rissoi, Macroparalepis
macrurus. B, Benthalbclla dentata, Scopelarchua nicholai, Scopelorchus t/nrnthcri, Scopelarchua sp.,
Evermannella indica. C, Anotoptcrus pharao, Bathyleptus lisae, Ditropichthys sp., Cololabis saira. D,
Scrrivomer xcctnr, X< michthys scolopaccus.

666

U.S. FISH AND WILDLIFE SERVICE

111. Scopelarchus nichohl ( Parr) .

Figure 25B.
120.50, H6204, (1) 42.5 mm.; 120.80, H6204, (1) 62 mm.

112. Scopelarchus guentheri Alcock.

Figure 25B.
108.63, C6303, (1) 50 mm.; 110.35, C6303, (1) 46 mm.

113. Scopel-archus sp.

Figure 25B.

84.70, C6303, (1) 28 mm.; 90.47, C6208, (1) 26 mm.;
97.40, C6303, (2) 37 mm. ; 110.46, C6303, (1) 28 mm.

There is a very good possibility that these speci-
mens represent an undescribed species.

EVERMANNELLIDAE

114. Evermannella indica Brauer.

Figure 25B.
120.90, H6204, (1) 55.5 mm.

ANOTOPTERIDAE

115. Anotopterws pharao Zugmayer.

Figure 25C.

60.180, H6204, (1) 173 mm.; 90.120, H6204, (1) 80.5
mm.; 90.160, H6204, (1) 59 mm.; 100.140, H6204, (1) ca.
179 mm.; 100.160, H6204, (2) 96-103 mm.

APODES
DERICHTHYIDAE

116. Derichtkys serpentinus Gill.

Figure 26A.
108.63,06303, (1) 200 mm.

This specimen and one in the collections of
Scripps Institution of Oceanography from about
215 km. (135 miles) southward of Punta Eugenia
are the first records of this species from this area.

CYEMIDAE

117. Cyema atrum Giinther.

Figure 26A.

60.70, H6204, (1) 1014- mm.; 60.100, H6204, (1) 145+
mm. ; 60.140, H6204, (1) 1264- mm.; 60.180, H6204, (1)
1314- mm.; 70.200, H6204, (1) 1064- mm.; 80.100, H6204,
(1) 964- mm.; 83.90. C6203, (1) 50 mm.; 90.120, H6204,
(1) 1074- mm.; 100.60, H6204, (1) 115+ mm.; 100.80,
H6204, (1) 100+ mm.; 100.160, H6204, (3) 125-134+
mm.; 110.160, H6204, (1) 147+ mm.; 120.50, H6204, (1)
110+ mm.

SERRIVOMERIDAE

118. Serrivomer sector Garman.

Figure 25D.

60.60, H6204, (1) 557+ mm. ; 83.77, C6303, (1) 582 mm. ;
84.70, C6303, (1) 461 mm. ; 86.92, C6303, (15) 312-645 mm. ;
87.80, C6303, (4) 500-541 mm.; 87.90, C6303, (2) 436-
537 mm. ; 100.60, H6204, (1) 461+ mm. ; 100.65, C6303, (1)
386 mm.; 108.63, C6303, (2) 532-574 mm.; 110.120, H6204,

(1) 490+ mm.; 120.70, H6204, (1) 532+ mm.

NEMICHTHYIDAE

119. Avocettina boicersi (Garman).

Figure 26A.

60.100, H6204, (1) 551 mm.; 84.67, C6303, (1) 320 mm.;
86.92, C6303, (8) 395-675 mm.; 87.80, C6303, (5) 319-550
mm.; 87.90, C6303, (2) 460-462 mm.; 90.110, C6303, (1)
229 mm.; 90.160, H6204, (1) 445+ mm.; 93.100, C6303,

(2) 395-485 mm.; 100.100. H6204, (1) 612 mm.; 110.120,
H6204, (1) 541 mm.; 120.70, H6204, (1) 532 mm.; 120.80,
H6204, (1) 499+ mm. ; 123.50, B6203, (5) ca. 364-510 mm.

120. Nemichthys scolopaceus Richardson.

Figure 25D.

60.140, H6204, (1) 453 mm. ; 60.160, B6203, (1) 477 mm. ;
60.200, H6204, (1) 621 mm. ; 70.80b, B6203, (1) 545+ mm. ;
70.80, C6208, (1) 500+ mm.; 73.200, B6203, (1) 392 mm.;
80.90, H6204, (1) 561 mm. ; 80.160, C6208, (5) 108-252 mm, ;
90.70, H6204, (1) 273 mm.; 90.140, H6204, (1) 442 mm.;
90.160, C6208, (17) 118-220 mm.; 97.40, C6303, (2) 300-
350 mm.; 100.40, C6303, (1) 406 mm.; 100.65, C6303, (1)
525 mm.; 120.45, H6204, (1) 761 mm.; 120.60, H6204, (1)
607 mm. ; 123.50, B6203, (1) 761 mm.

121. Nemichthyidae, unidentified.
120.70, H6204, (1) 327+ mm.

This specimen is badly damaged.

CONGRIDAE

122. Ariosoma gilberti (Ogilby).

Figure 26A.
137.35, B6212, (3) 135-223 mm.; 140.35, B6212, (1)
145 mm.; 147.30, B6212, (1) 155 mm.

123. Congridae, unidentified.
133.35, B6212, (1) 144 mm.

This Congrina "like" specimen is damaged.

OPHICHTHYIDAE

124. Ophichthyidae, unidentified.

137.35, B6212, (1) 71 mm.; 143.30, B6212, (1) 121 mm.
These leptocephali have not been otherwise
identified.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

667

SYNENTOGNATHI

SCOMBERESOCIDAE

125. Cololabis saira (Brevoort).

Figure 25C.

60.200, B6203, (1) 66 mm.; 70.200, H6204, (1) 57 mm.;
80.100, B6203, (1) 69 mm.; 84.92, B6303, (1) 31.5 mm.;
127.45, B6212, (1) 25 mm.

ANACANTHINI
MORIDAE

126. Melwnonus zugmayeri Norman?

Figure 26B.
60.90, H6204, (1) 112mm.; 60.160, H6204, (1) 120 mm.;
86.92, C6303, (1) 214 mm.; 87.80, C6303, (1) 115 mm.;
108.63, C6303, (2) 148-209 mm.

These specimens are tentatively identified as
this species pending further study (D. M. Cohen,
personal communication).

GADIDAE

127. Merluccius products (Ayres).

Figure 26B.

60.55, C6208, (7) 179-114 mm.; 65.54, C6208, (1) 265
mm.; 70.51, C6208, (186) 150-244 mm.; 80.55, H6204, (1)
166 mm. ; 80.60, C6208, (4) 375-415 mm. ; 80.70, H6204, (1)
10.5 mm.; 80.80, H6204, (2) 9-10 mm.; 80.90, H6204, (9)
7.5-10 mm.; 80.100, H6204, (12) 6-11 mm.; 82.45, C6208,
(38) 80-220 mm. ; 82.69, C6303, (38) 285-518 mm. ; 83.70a,
B6303, (1) 471 mm.; 83.70, C6303, (9) 327-505 mm.';
83.77, C6303, (5) 299-361 mm.; 84.67, C6303, (4) 396-504
mm.; 84.70, C6303, (2) 374-478 mm.; 84.71, C6303, (1)
492 mm.; 90.45a, H6105, (1) juvenile, damaged; 90.47,
C6208, (3) 192-345 mm. ; 90.48a, H6105, (3) 16-25.5 mm. ;
90.48b, 96105, (33) 17-31.5 mm.; 90.48c, H6105, (6) 20.5-
36 mm.; 94.28b, O6208, (1) 430 mm.; 94.30, C6208, (7)
162-420 mm.; 94.32b, B6204, (1) 17 mm.; 95.31d, B6204,
(3) 19.5-36.5 mm.; 97.40, C6303, (29) 327-688 mm.; 99.31,
C6208, (2) 192-370 mm.; 100.40, H6204, (4) 20-22 mm.;
100.40, C6203, (1) 398 mm.; 110.35, H6204, (1) 23 mm.;
110.35, C6303, (131) 244-577 mm.; 110.36, C6303, (3) 376-
496 mm.; 111.36a, C6303, (495) ca. 258-598 mm.; 111.36b,
C6303, (ca. 300) ca. 239-515 mm.; 111.37a, 06303, (65)
282-479 mm. ; 113.34a. C6303, (8) 20.5-392 mm. ; 120.45,
H6204, (2) 19-23 mm. ; 120.45. B6212, (1) 266 mm. ; 120.50,
H6204, (2) 31-34.5 mm.; 120.60, H6204, (1) 23.5 mm.;
147.30, B6212, (8) 105-150 mm.

MACROURIDAE

128. Coryphaenoides acrolepis (Bean) ?

Figure 26B.
60.60, H6204, (1) 515 mm.

The species of this genus in this area are con-
fused, and this identification must be tentative
until the problems are resolved.

129. Macrouridae, unidentified.

86.92, C6303, (2) 333-347 mm.

These two specimens from about 305 km. (190
miles) SW. of Point Conception, Calif., repre-
sent an undescribed genus and species of
bathy pelagic macrouroid (C. L. Hubbs, personal
communication) .

130. Macrouridae, unidentified.

100.40, H6204, (1) 32 mm.

This specimen is too small to identify without
comparative material.

LOPHOBRANCHII

SYNGNATHIDAE

131. Syngnathus arcta (Jenkins and Evermann).
90.45, H6105, (1) 166 mm.; 95.31b, B6204, (1) 72 mm.

ALLOTRIOGNATHI
TRACHIPTERIDAE

132. Desmodema polystictum (Ogilby).

Figure 26C.
89.90, C6303, (1) 614 mm.; 90.160, C6208, (1) 1,106
mm. ; 100.80, H6204, (1) 455+ mm.

133. Trachipterus t. altwelis Kner.

Figure 26C.
60.90, C6208, (2) 49.5-1,435 mm.; 70.60, C6208, (1) 1,014
mm.; 80.52, C6208, (2) 177-297 mm.; 82.45, C6208, (2)
187-275 mm. ; 85.68, C6303, (1) 133 mm. ; 86.92, C6303, ( 1 )
605 mm.; 90.47, O6208, (1) 1,000 mm.; 93.29, C6208, (1)
445 mm

LOPHOTIDAE

134. Lophotus sp.

Figure 26C.
80.170, C6208, (1) 46.5 mm.

This specimen is too small to allow specific
identification (J. E. Fitch, personal communica-
tion).

BERYCOMORPHI
MELAMPHAIDAE

135. Scopelogadm mizolepis bispinosus (Gil-
bert).

Figure 26D.

60.60, H6204, (2) 24-72 mm. : 60.80, C6208, (1) 33 mm.;
60.90. H6204, (3) 18-51 mm.; 60.100, H6204, (2) 13-75

668

U.S. FISH AND WILDLIFE SERVICE

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Figure 26. — Locations of capture of: A, Derichthys serpentinus, Cyema atrum, Avocettina bowersi, Ariosoma
gilberti. B, Melanonus zugmaycrl'i, Merlucoius productus, Coryphaenoides acrolcpsisl, C, Desmodema
polystictum, Trachipterus trachipterus altivelis, Lophotus sp. D, Scopelogadus mizolepis bispinosus,
Poromitra crassiceps, Poromitra sp., Scopeloberyx robust us.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

669

mm.; 60.120. H6204, (10) 63-75 mm.; 60.140, H6204, (1)
67 mm.; 60.160, H6204, (2) 64-75 mm.; 60.180, H6204,
(2) 30-43 mm. ; 60.200, B6203, (1) 53 mm. ; 70.200, H6204,

(1) 28 mm.; 80.55, H6204, (1) 63 mm.; 80.60. H6204, (2)
18-68 mm.; 80.80, H6204, (7) 45-60 mm.; 80.90, B6203,

(2) 41-47 mm. ; 80.90, H6204, (3) 65-79 mm. ; 86.92, C6303,
(13) 25-90 mm.; 87.90, C6303, (8) 29-90 mm.; 90.45a,
H6105, (1) 47 mm.; 90.70. H6204, (11) 45-68 mm.; 90.70,
C6208, (3) 61-70 mm. ; 90.110, B6203, (1) 70 mm. ; 90.140,
H6204, (2) 66-74 mm.; 90.160, H6204, (2) 21^4 mm.;
90.160, C6208, (2) 56-58 mm.; 93.100, C6303, (1) 35 mm.;
94.32a. B6204, (2) 56-58 mm.; 97.40, C6303, (12) 36-45
mm.; 100.40, H6204, (2) 54-55 mm.; 100.40, C6303, (1) 49
mm.; 100.60, H6204, (5) 56-82 mm.; 100.65, C6303, (17)
43-76 mm. ; 100.80, H6204, (4) 20-52 mm. ; 100.90, H6204,
(5) 34-74 mm.; 100.100, H6204, (3) 35-54 mm.; 100.120,
H6204, (1) 56 mm.; 100.140, H6204, (1) 53 mm.; 100.160,
H6204, (3) 25-64 mm.; 108.63, C6303, (26) 45-87 mm.;
110.35, H6204, (1) 62 mm.; 110.35, C6303, (2) 30-43 mm.;
110.40, H6204, (1) 45 mm.; 110.50, B6203, (2) 55.5
mm.; 110.120, H6204, (3) 18-79 mm.; 110.160, H6204, (5)
10-83 mm. ; 120.45, H6204, (1) 54 mm. ; 120.60, H6204, (1)
55 mm. ; 120.70, H6204, (6) 45-62 mm. ; 120.80, H6204, (3)
28-51 mm.; 120.90, H6204, (3) 46-83 mm.; 137.50, B6203,
(5) 26-58 mm.

This species, previously known as Melamphaes
bispinosus or Seopelogadus bispinosus, has re-
cently been shown to be a subspecies of Scopelo-
gadus mizolepis (Giinther) by Ebeling (1963:19).

136. Poromitra crassiceps (Giinther).

Figure 26D.

60.60. H6204, (1) 127 mm. ; 60.100, H6204, (1) 117 mm. ;
60.140, H6204, (1) 30 mm.; 60.180, H6204, (2) 22-45.5
mm.; 80.90, H6204, (1) 24 mm.; 90.48b, H6105, (1) 25
mm.; 90.160, C6208, (2) 91-96 mm.; 120.45, H6204, (1) 89
mm.; 120.90, H6204, (2) 92-97 mm.

This species has been listed under the name of
its junior synonym, Poromitra cristiceps (Gilbert) .

137. Pjoromitra sp.

Figure 26D.

70.200, H6204. (2) 51-64 mm.; 100.100, H6204, (1) 70
mm.; 120.70, H6204, (1) 75 mm.

These specimens, with relatively small eyes and
a low number of dorsal fin rays (III, 10 or 11) are
representative of a new species. This was called
to our attention by A. W. Ebeling (personal com-
munication), who is preparing a detailed descrip-
tion for publication.

138. Scopeloberyx rdbutus (Giinther).

Figure 26D.

60.180, H6204. (1) 31 mm.; 70.200, H6204, (2) 18-21
mm. ; 80.180, C6208, (1) 12 mm. ; 90.200, H6204, (2) 31.5-
32 mm.; 100.60, II6204, (1) 71.5 nun.; 100.160, H6204, (6)

18-32 mm. ; 120.45, H6204, (3) 57-59 mm.; 120.70, H6204,
(1) 60 mm.

This species has generally been known in this
area as Scopeloberyx nycterinus (Gilbert). The
synonymy of S. nycterinus with S. robustus has
recently been determined by A. W. Ebeling (per-
sonal communication).

139. Melamph-aes acanthamus Ebeling.

Figure 27A.

90.45a, H6105, (2) 83-92 mm.; 100.65, C6303, (1) 81
mm

140. Melamphaes indicus Ebeling.

Figure 27A.
90.160, H6204, (1) 35.5 mm.

This record extends the known range of this
species eastward from west of the Hawaiian Is-
lands, as delimited by Ebeling (1962, fig. 47).

141. Melamphaes laeviceps Ebeling.

Figure 27B.

60.200a. B6203. (2) 28-29 mm.; 60.200, H6204, (1) 27
mm.; 73.200, B6203, (4) 24-29 mm.; 80.200, C6208, (3)
27-28 mm.; 87.200, B6203, (1) 27 mm.; 90.150, C6208, (1)
26 mm.; 90.160, H6204, (1) 28 mm.; 100.140, H6204, (1)

28 mm

This species previously has only been reported
from the tropical eastern and central Pacific (Ebel-
ing, 1962, fig. 53).

142. Melamphaes longivelis Parr.

Figure 27B.

90.120, H6204, (1) 33 mm.

This specimen represents a range extension for
the species of about 260 km. (160 miles) northeast
from that shown by Ebeling (1962 : 77, not fig. 44) .

143. Melamphaes lugubris Gilbert.

Figure 27B.
60.60, H6204, (2) 30-84 mm. ; 60.80, H6204, (1) 55 mm. ;
60.80, C6208, (1) 19 mm.; 60.90, H6204. (3) 22-79 mm.;
60.120, B6203, (2) 38 mm.; 70.80b, B6203, ( 1 ) 37 mm.;
80.55, H6204, (3) 38-41 mm.; 80.60, H6204. (1) 44 mm.;
80.75, B6303, (1) 17 mm. ; 80.80, H6204, (3) all ca. 40 mm. ;
80.90, H6204, (5) 37-43 mm.; 80.100, B6203, (1) 37 mm.;
80.100, H6204, (2) 20-22 mm. ; 80.110, B6203. (1) 13 mm. ;
83.77, C6303, (1) 22 mm.; 84.92, B6303. (7) 36-39 mm.;
86.92, O6303, (5) 36-52 mm. ; 87.80, C6303, (4) 35-38 mm. ;
90.45a, H6105, (4) 51-77 mm.; 90.70, H6204, (2) 40-43
mm.; 90.70, C6208. (7) 25.5-50 mm.; 97.40, C6303, (7) 31-
36 mm.; 97.50, B6203, (1) 38 mm.; 100.60, 116204, (1) 21
mm.; 100.65, C6303, (1) 38 mm.; 108.63, C6303, (2) 32-37
mm.

670

U.S. FISH AND WILDLIFE SERVICE

144. Melamphaes macrocephalm Parr.

Figure 27A.
120.90, H6204, (1) 116 mm.

145. Melamphaes parvus Ebeling.

Figure 27A.

60.120, B6203, (1) 25.5 mm.; 60.120, H6204, (2) 35-37.5
mm.; 60.140, H6204. (4) 36-45 mm.; 60.160, B6203, (3)
36-18 mm.; 60.180, H6204, (1) 27 mm.; 80.80, H6204, (3)
37-38 mm.; 80.90, B6203, (1) 36 mm.; 80.90. H6204, (1)
45 mm.; S0.200, C6208, (1) 18 mm.; 82.69, C6303, (2) 33-
38 mm.; 84.92, B6303, (3) 43-47 mm.; 86.92, C6303, (5)
33-44 mm. ; 87.80, C6303, (2) 38-43 mm. ; 90.70. H6204, (2)
ca. 3S mm.; 97.40, C6303. (1) 39 mm.; 100.60, H6204,
(1) 41 mm.: 100.65, C6303. (20) 31-48 mm.; 100.160,
H6204, (1) 18 mm.; 108.63, C6303, (6) 30-43 mm.

146. Melamphaes sub orbital is (Gill).

Figure 27B.
60.180. H6204, (1) 37 mm.

147. Melamphaes spp.

60.200, H6204, (1) 15 mm.; 80.80, H6204, (1) 17 mm.;
133.35, B6212, (1) 15 mm.

These damaged specimens probably represent
more than one species.

ANOPLOGASTERIDAE

148. Anoplogaster cornuta (Valenciennes).

Figure 27A.
80.200, C6208, (1) 94 mm.; 86.92, C6303, (7) 86-121
mm.; 87.80, C6303, (1) 94.5 mm.; 90.45a, H6105, (1) 94
mm. ; 108.63, O6303, (1) 88 mm.

As pointed out by Grey (1955: 293), Caulolepis
longidens Gill is a junior synonym of this species.

PERCOMORPHI
CARISTIIDAE

149. C aristius macropus (Bellotti).

Figure 29A.
83.77, 06303, (1) 165 mm.

150. C aristius maderenis Maul?

Figures 28 and 29A.
108.63, C6303, (2) 148-160 mm.
The phylogenetic position of the Caristiidae
and the true identity of these specimens are under
study (C. L. Hubbs, personal communication).

SERRANIDAE

151. Serranidae, unidentified.
140.30, B6212, (6) 9-12 mm.

These specimens are too small to identify with-
out comparative material.

CHEILODIPTERIDAE

152. Howetta brodiei (Ogilby) ?

Figure 29A.

60.120, B6203, (2) 52.5-70.5 mm.; 60.160, H6204, (1) 71
mm.; 80.80, H6204, (1) 29.5 mm.; 80.90, H6204, (3) 30.5-
34 mm. ; 100.80, H6204, (1) 36 mm.

The generic limits and the intrageneric com-
ponents of Howella Ogilby 1898 are not definitive
at this time. It apparently contains as synonyms
the genera Galeagra Heller and Snodgrass 1903
and Rhectogramma Norman 1930; and, also ap-
parently, these genera should be included in the
family Cheilodipteridae (rather than Serranidae).
The above specimens may represent a new species,
but their characters are close to the descriptions
given by Ogilby (1898:734) for H. brodiei from
Lord Howe Island, and are similar to the accounts
of this species from the Philippines given by Herre
and Herald (1951:330) and from the North At-
lantic Ocean by Koefoed (1952 : 5) . Other speci-
mens of Howella from the equatorial eastern Pa-
cific that we have examined are specifically distinct
from these tentatively designated as H. brodiei,
and appear to be the Galeagra pammelas of Heller
and Snodgrass. The monotypic Sphyraenops
bairdianus Poey that has at times been placed in
this complex apparently is generically distinct.

CARANGIDAE

153. Trachurus symmetricus (Ayres).

Figure 29A.

68.50, C6208, (1) 180 mm.; 70.80, C6208, (25) 64.5-503
mm.; 70.90, C6208, (1) 61 mm.; 70.100, C6208, (1) 60
mm.; 80.70, C6208, (1) 65 mm.; 80.80, C6208, (9) 28-69
mm.; 90.4Sb, H6105, (1) ca. 5 mm.; 90.49b, C6208, (12)
51-224 mm.; 90.80, C6208, (5) 23.5-64.5 mm.; 90.150,
C6208, (1) 40 mm.; 91.39a, C6208, (1) 190 mm.; 91.39b.
C6208, (3) 100-240 mm.; 93.26, C6208, (2) 100-125 mm.;
94.28b, C6208, (1) 435 mm.; 94.29b, C6208, (3) 335 mm.;
94.29c, C6208, (12) ca. 125 mm. ; 99.31, C6208, size and num-
ber not recorded, discarded at sea; 113.34a, C6303, (1) 63
mm. ; 120.50, H6204, (1) 23 mm.

Nine of the above records of jack mackerel were
based on larvae or small juveniles. One of these
was taken about 420 miles offshore (90.150, C6208) .
At station 70.80, C6208, about 185 km. (115 miles)
offshore, a night surface drag with the Cobb trawl
caught 1 small juvenile and 24 spawning and spent
males and females.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

671

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Figure 27. — Locations of capture of: A, Mclamphacs acanthomus, ilrlamphaes indicus, ifclamphacx macro-
cephalus, Mvlamphaes parvus, Anoploffiistrr rorniita. B, ilrtamphacx tacriccps, Melatnphaes longivelis,
Melamphaes lugubris, Melamphacs suborbitalitt. C, Cithariclitlij/.s sordidus, Citharichthys xanthostiffma,
Citharichthys stiff maeus, Bothus leopardinus. I), Microstomus pacificus, Olyptocephalus zachirus,
Eopsetta jordani.

672

U.S. FISH AND WILDLIFE SERVICE

CORYPHAENIDAE

154. Coryphaena hippurus Linnaeus.
147.30, B6212, (1) ca. 24 mm. damaged.

This specimen was taken about 80 km. (50
miles) offshore, south of Almejas Bay, Baja Cali-
fornia.

STROMATEIDAE

155. Cubiceps gracilis (Lowe) .

Figure 29B.

80.180, C6208, (2) 32.5^7 mm.; 80.190, C6208, (2) 31-
40.5 mm.

Two recognized species of Cubiceps occur in the
eastern Pacific, and C. gracilis appears to be the
most suitable name to apply to the above speci-
mens. The other species, C. carinatus Nichols and
Murphy (1944:245), has fewer dorsal and anal
fin softrays, fewer lateral line scales, and a more
tropical distribution.

156. Iciehthys lockingtoni Jordan and Gilbert.

Figure 29B.

60.80, H6204, (3) 11-15 mm.; 60.140, H6204, (2) 98-193
mm.; 70.80, B6203, (6) 20.5-27 mm.; 80.60, H6204, (1)
19 mm.; 80.90, B6203, (4) 2CM6 mm.; 80.90, H6204, (13)
1L44.5 mm.; 80.100, B6203, (1) 19.5 mm.; 80.100, H6204,
(2) 9-10.5 mm.; 80.120, B6203, (1) 14.5 mm.; 83.70a,
B6303, (5) 27-42.5 mm.; 83.70c, B6303, (1) 32.5 mm.;
83.77, C6303, (1) 29.5 mm.; 90.45b, H6105, (1) 26 mm.;
90.48c, H6105, (1) 57.5 mm.; 90.80, C6208, (1) 40 mm.;
90.120, H6204, (1) 8 mm.; 94.29d, C6208, (3) 81-95 mm.;
100.65, C6303, (1) 39 mm.

157. Palometa simillima. (Ayres).

Figure 29B.

80.52, C6208, (3) 51.5-61 mm. ; 82.45, C6208, (1) 48 mm. ;
93.26, C6208, (83) ca. 50-75 mm. ; 94.28a, C6208, (2) small,
size not recorded, discarded at sea; 94.28b, C6208, (4)
ca. 50-75 mm.; 94.29b, C6208, (37) 78-147 mm.; 94.29c,
C6208, (3) ca. 50 mm.; 99.31, C6208, (32) 85-165 mm.;
120.50, H6204, (7) 12-20 mm.

TETRAGONURIDAE

158. Tetragonurus cuvieri Risso.

Figure 29B.
100.65, C6303, (1) 51 mm.; 88.105a, B6303, (1) 37 mm.

When first seen in the cod end of the collapsible
net, the 37-mm. specimen was alive within the
cavity of a pyrosome. A few records of associa-
tion of T. atlanticus Lowe and T. cuvieri with
medusae were summarized by Mansueti (1963 : 59-
60).

PELAGIC FISHES, CALIFORNIA CURRENT AREA
795-358 — 66 1 1

BRAMIDAE

159. Brama japonica Hilegendorf.

Figure 29C.
70.80, C6208, (3) 215-220 mm.; 70.200, H6204, (1) 15.5
mm. ; 80.180, C6208, (1) 52.5 mm.

Two names previously used for pomfrets from
the North Pacific, B. brama (Bonnaterre) and B.
rail (Bloch), do not apply to this species (G. W.
Mead, personal communication).

160. Pteraclis velifera (Pallas) ?

Figure 29C.
110.160, H6204, (1) 9.5 mm.

This small specimen can be identified only ten-
tatively at this time (G. W. Mead, personal com-
munication).

GEMPYLIDAE

161. Gempylus serpens Cuvier.

Figure 29C.

70.200, H6204, (1) 28 mm.; 80.180, C6208, (1) 52 mm.;
90.180, C6208, (1) 105 mm.

TRICHIURIDAE

162. Lepidopus xantusi Goode and Bean.

Figure 29C.
113.34a, C6303, (2) 230-249 mm.

SCOMBRIDAE

163. Sarda lineolata (Girard).

92.28, C6208, (3) 2-3 kg., discarded at sea, no length
record taken; 93.26, C6208, (8) 2-4 kg., no length record;
93.28, C6208, (60) 340-490 mm.; 94.28b, C6208, (18) all
ca. 300 mm.; 94.29b, C6208 (1) 335 mm.; 94.29c, C6208,
(1) 4 kg., no length record; 94.30, C6208, (20) 2-4 kg., no
length record ; 95.30, C6208, (11) 2-A kg., no length record ;
113.34b, C6303, (1) adult, no size record.

These records are of adult fish taken close
inshore and generally near the surface'.

164. Scomber japonicus Houttuyn.

90.49b, C6208, (1) 288 mm.; 99.31, C6208, (16) 300-340
mm.

This species has also been referred to as Scomber
diego Ayres, Pneumatophorus japonicus, and
Pneumatophorus diego. This complex apparently
also includes Scomber colias Gmelin of the At-
lantic, and has previously been cited as such by
various authors (B. B. Collette, personal com-
munication) .

673

Figure 28. — Caristius maderensist, 160 mm. SL, station 108.63, C6303.

SCIAENIDAE

165. Seriphus politus Ayres.

93.25, C6208, (1) 175 mm.; 94.29c, C6208, (3) 165-186
mm

166. Roncador stearnsi ( Steindachner) .

93.26, C6208, (131) ca. 150-175 mm.

SPHYRAENIDAE

167. Sphyraena argentea Girard.
93.26, C6208, (4) 260-325 mm.

CHIASMODONT1DAE

168. Chiasmodon niger Johnson.

120.90, H6204, (1) 47.5 mm.

This specimen was taken about 320 km. (200
miles) west of Punta Eugenia, Baja California.

169. Kali sp.

100.100, H6204, (1) 172 mm.

This specimen was taken about 480 km. (300
miles) west of Rosario Bay, Baja California. It
cannot be specifically identified from current ref-
erences, and t lie generic limits of Kali are con-
fused— two genera appear to be included under
this one name (D. M. Cohen, personal communi-

cation). Compared to specimens identified as K.
indica (Lloyd) and K. normani (Parr) in the col-
lections of Scripps Institution of Oceanography,
this specimen is unique in having a reduced num-
ber of broad-based, short, blunt teeth in both jaws.

170. Pseudoscopelus scriptus Liitken.

137.50, B6203, (1) 83.5 mm.

This specimen was taken about 160 km. (100
miles) west of Santa Maria Bay, Baja California.
Parr (1933: 36-42) considered P. scriptus to con-
sist of two subspecies and also described a new
species, P. altipinnis. The above specimen is
closer to the description Parr gave for P. scriptus,
but it is possible that the two species are synony-
mous (R. J. Lavenberg, personal communication).

SCORPAENIDAE

171. Sebastolobus alascanus Bean.

Figure 29D.
60.60, H6204, fl) 26 mm.

172. Selaxtolobus altivelis Gilbert.

Figure 291).

60.120, H6204, (li 40.5 mm.; 80.55, H6204. (5) 30.5-

39.5 mm.; 80.60, B6203. (1) 31 mm.; S0.60, IIG204, (1)

29.5 mm.: 80.70, C(i2(>s. ill 14.5 mm.: 80.80, H6204, (2)

33 mm.; 80.90, H6204. ID 36 mm.; 84.92, B6303. (2)

674

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Figube 29. — Locations of capture of: A, Curistius macropus, Caristius maderen&tef,
Hotvella brodiei?, Trachtirus symmetricus. B, Cubiceps gracilis, Icirhthys loekingtoni,
Palometa simillima, Tetragonurus cuvieri. C, Brama japonica, Pteraclis veliferaf,
Gempylus serpens, Lepidopits xantusi. D, Sebastolobus alascanus, Sebastolobus
altivelis, Coryphopteriis nicholsi.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

675

30-35 mm.; 90.32, H6204, (3) 34-47.5 mm.; 90.70, H6204,
(1) 41.5 mm. ; 90.70, C6208, (3) 13-15.5 mm. ; 97.50, B6203,
(3) 35.5-42 mm. ; 100.40, H6204, (4) 39.5-^15.5 mm. ; 110.35,
C6303, (4) 28-36.5 mm.

All these specimens are pelagic, prejuvenile
specimens, taken from close inshore to 480 km.
(300 miles) at sea.

173. Sebastodes diploproa (Gilbert).
91.39b, C6208, (100+) ca. 31^1 mm.

174. Sebastodes saxicolu (Gilbert).
60.60, H6204, (5) 16-23 mm.

175. Sebastodes proriger (Jordan and Gilbert) ?

60.60, H6204, (2) both 26.5 mm.

This identification is uncertain because of the
small size of the specimens.

176. Sebastodes goodei Eigenmann and Eigen-
mann.

68.50, C6208, (8) 197-231 mm.

177. Sebastodes jordani ( Gilbert) .
94.30, C6208, (2) 188-192 mm.

178. Sebastodes spp.

60.60, H6204, (2) 10-13 mm.; 60.70, H6204, (1) «5.5

mm.; 70.S0-5N, B6203, (1) 15 mm.; 80.90, B6203, (1) 15.5

mm.; 90.48a, H6105, (1) 4.5 mm.; 90.48b, H6105, (1) 21.5
mm.

Specific identifications were not made because
of the small size of these specimens.

ANOPLOPOMATIDAE

179. Arwplopoma fimbria (Pallas).
68.50, C6208, (1) 182 mm.

ZANIOLEPIDAE

180. Zaniolepis frenata Eigenmann?

90.32, B6203, (1) 22 mm.; 113.34a, C6303, (1) 39.5 mm.

These two small specimens may represent the
sympatric Z. latipinnis Girard — adequate com-
parable material is not available to confirm our
identification. The larger specimen appears, how-
ever, to be Z. frenata, because its third anal spine
is shorter than the second.

AGONIDAE

181. Agonidae, unidentified.

90.48a, H6105, (1) 20.5 mm.; 90.48b, H6105, (2) 24.5-
24.5 mm.; 90.60, B6203, (1) 19 mm.; 113.34a, C6303, (1)
15.5 mm.

Comparative material is not available that will
allow identification of these small specimens
(J. E. Fitch, personal communication) .

GOBIIDAE

182. Caryphoptei'usnicholsi (Bean).

Figure 290.

60.140, H6204, (2) 20-29 mm.; 80.90, H6204, (1) 15.5
mm.

These specimens, taken about 560 and 260 km.
(350 and 160 miles) offshore, appear to be pelagic,
oceanic, protracted prejuvenile stages of this spe-
cies, which is generally known as an inshore, shal-
low-water, benthic inhabitant. Other specimens
of this form have been taken in offshore waters at
various times in CalCOFI routine, 140-m.-deep
plankton tows.

183. Gobiidae, unidentified.
90.48a, H6105, (2) 7-8 mm.

BATRACHOIDIDAE

184. Porwhtkys notatits Girard.
94.29c, C6208, (2) 98-133 mm.

185. Parichthys sp.

65.54, C6208, (1) 125 mm.

This specimen was not identified to species and
was discarded at sea.

BLENNIIDAE

186. Hypsoblennius gentilis (Girard).
123.45, B6212, (1) 15 mm.

ZOARCIDAE

187. Melarwstigma pa?rvmel-as Gilbert.
90.45a, H61 05, (1) 108 mm.

HETEROSTOMATA

BOTHIDAE

188. Citharichthys sordidtis (Girard).

Figure 27C.
60.60, C6208, (1) 25 mm.; 70.51, C6208, (6) 27-36 mm.;
70.60, C6208, (1) 32 mm.; 70.80-5N, B6203, (1) 27 mm.;
80.60, B6203, (1) 25.5 mm; 80.60, C6208, (3) 28-32 mm.;
S4.92, B6303, (1) 16 mm.

These are all pelagic larval and juvenile speci-
mens taken from close inshore to about 290 km.
(180 miles) at sea.

676

U.S. FISH AND WILDLIFE SERVICE

189. C 'ithwichthys xanthostigma Gilbert.

Figure 27C.

113.34a, C6303, (a) all ca. 22 mm.

190. C itharichthys stigm teus Jordan and Gilbert.

Figure 27C.

60.60, H6204, (2) 32.5-38.5 mm.; 60.60, C6208, (1) 26.5
mm; 60.70, C6208, (1) 28.5 mm.; 60.80, C6208, (1) 32.5
mm.; 70.51, C6208, (6) 29.5-34 mm.; 80.60, C6208, (8)
24.5-30 mm.; 80.100, H6204, (2) 26.5-28 mm.; 83.70c,
B6303, (1) 21 mm. ; 83.90, C6303, (1) 22 mm. ; 84.92, B6303,
(1) 22 mm.; 90.45, H6105, (1) 29.5 mm.; 90.45a, H6105,

(1) 29 mm. ; 90.90, C6303, (14) 13-21.5 mm. ; 90.48c, H6105,

(2) 31 mm.; 97.40, C6303, (3) 23.5-26.5 mm.

These are all pelagic larval and juvenile speci-
mens taken from close inshore to about 320 km.
(200 miles) at sea.

191. C itharichthys sp.

67.50, C6208, (1) 150 mm.

This specimen was discarded at sea and not spe-
cifically identified.

192. Bothus leopard inus (Giinther).

Figure 27C.
140.35, B6212, (2) 13-20 mm.

These specimens may be B. constellatus (Jor-
dan), if B. constellatus is a distant species. Until
distinction or synonymy can be established, we
choose to use the earlier name.

PLEURONECTIDAE

193. Microstomia pacificus (Lockington) .

Figure 27D.

70.51, C6208, (1) 28.5 mm. ; 70.60, C6208, (1) 26.5 mm. ;
80.70, H6204, (1) 21.5 mm.; 84.92, B6303. (1) 24 mm.;
97.40, C6303, (1) 30 mm.; 100.65, C6303, (2) 26-34 mm.;
100.160, H6204, (1) 42 mm.; 107.60, C6303, (1) 28.5 mm.

These larval specimens were taken from close in-
shore to about 840 km. (520 miles) off northern
Baja California.

194. Glyptocephdbus zachirus Lockington.

Figure 27D.
60.70, C6208, (1) 55.5 mm. ; 60.90, C6208, (3) 36-62 mm. ;
60.100, C6208, (1) 33 mm.; 70.60, C6208, (3) 39-45 mm.;
80.60, C6208, (1) 51mm.

These larval specimens were taken about 55 to
315 km. (35 to 195 miles) offshore.

195. Eopsetta jordani (Lockington).

Figure 27D.
60.70, H6204, (1) 20 mm.

CYNOGLOSSIDAE

196. Symphurus atrwauda (Jordan and Gilbert) .
94.30, C6208, (1) 130 mm.

PLECTOGNATHI
MOLIDAE

197. Mola mola- (Linnaeus).

94.28a, C6208, (13) "moderate size"; 94.28b, C6208. (4)
500-750 mm.; 94.29b, C6208, (3) all 380 mm.; 94.29c,
C6208, 94.29d, C6208, (12) 378-1,460 mm.; (3) all ca. 450
mm.

PEDICULATI

ONEIRODIDAE

198. Oneirodes eschrichtii Lutken.

Figure 30.
80.80, H6204, (1) 52 mm.; 90.160, H6204, (1) 98 mm.;
100.140, H6204, (1) 25 mm.; 110.35, C6203, (1) 29 mm.;
120.45, H6204, (1) 26 mm.

These specimens fit the 0. eschrichtii group as
defined by Bertelsen (1951: 77-84), and further
compare well with 0. eschrichtii s.s. (R. H.
Rosenblatt, personal communication).

199. Oneirodes eschrichtii Lutken ?

Figure 30.

120.70, H6204, (2) 13.5-29.5 mm.

These two small specimens appear to represent
this species (P. Struhsaker, personal communica-
tion).

200. Oneirodes acanthim (Gilbert) ?

Figure 30.
123.50, B6203, (1) 24 mm.

This small specimen appears to represent this
species (P. Struhsaker, personal communication).

201. Chctenophryne parvicomts Regan and Tre-
wavas.

Figure 30.
108.63, C6303, (1) 52 mm.

202. Oneirodidae, unidentified.
110.140, H6204, (1) 14 mm.

The identity of this free-living male is uncertain.

PELAGIC FISHES, CALIFORNIA CURREiNT AREA

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Figure 30. — Locations of capture of : Oneirodes eschrichtii,
Oneirodes esohrwhtiif, Oneirodes acanthiasf, Chaeno-
pliryne parvioonus.

ALPHABETICAL LIST OF FISHES

The species, genera, families, and orders of
fishes taken on the pelagic survey are listed al-
phabetically. Each entry is followed by the phy-
logenetic sequence number assigned to that name.

Aethoprora elucens (Brauer), 80
AGONIDAE, 181
Agonidae, unidentified, 181
ALEPOOEPHALIDAE, 6-7
Alepocephahis tenebrosus Gilbert?, 6
ALLOTRIOGNATHI, 132-134
AXAOANTHINI, 126-130
Anoplogaster cornuta (Valenciennes), 148
AM HT,< KJASTERIDAE, 148
Anoploponut fimbria (Pallas), 179
ANOPLOPOMATIDAE, 179
ANOTOPTERIDAE, 115
Anotopterus pharao Zugmayer, 115
APODES, 116-124
Argentina sialis Gilbert. 14
ARGBNTINIDAE, 13-15
Irgyropelecus hawaiensis Schultz, 26
Argyropelecus intermedins Clark, 24

Argyropelecus lychnus Gannan, 25

Argyropelecus pacificus Schultz, 23

Argyropelecus sp., 27

Ariosoma gilbert i (Ogilby), 122

Aristostomias scintilkins Gilbert, 59

ASTROXESTHIDAE, 57

Avocettina bowersi (Garnian), 119

Bathophilus flemingi Aron and McCrery, 54

BATHYLACOXIDAE, 60

Bathylaco nigricans Goode and Bean, 60

BATHYLAGIDAE, 16-20

Bathylagus milleri Jordan and Gilbert, 20

Bathylagus ochotensis Schmidt, 17

Bathylagus pacificus Gilbert, 19

Bathylagus wesethi Bolin, 18

Bathyleptws li-sae Walters, 61

BATRACHOIMDAE, 184-185

Benthalbella dentata (Chapman), 110

Benthosema suborbitale (Gilbert), 68

BERYCOMORPHI, 135-148

BLEXXIIDAE, 186

Borostomias panamensis Regan and Trewavas, 57

BOTHIDAE, 188-192

Bothus leopardinus (Giinther), 192

Brama japonica Hilgendorf, 159

BRAMIDAE, 159-160

CARANGIDAE, 153

OAROHARHIXIDAE, 1

OARISTIIDAE, 149-150

Caristiu-s m-acropus ( Bellotti ) , 149

Caristius maderensis Maul?, 150

Ceratoscopelus townsendi (Eigenmann and Eigenmann),

103
OETOMIMIDAE, 63
OETUXOULI, 63

Chacnophryne parvioonus Regan and Trewavas, 201
OHAULIODOXTIDAE, 58
Chauliodm macouni Bean, 58
CHEILODIPTERIDAE, 152
Chiasmodon niger Johnson, 168
CHIASMODOXTIDAE, 168-170
Citharichthys sordidus (Girard), 188
Citharichthys sp., 191

Citharichthys stigmaeus Jordan and Gilbert, 190
Citharichthys xanthostigma Gilbert, 189
CLUPEIDAE, 4
Cololabis saira (Brevoort), 125
CONGRIDAE, 122-123
Congridae, unidentified, 123
Coryphaena hippurus Linnaeus, 154
CORYPHAEXIDAE, 154
Coryphacnoidcs acrolepis (Bean) ?, 128
Coryphopterus nicholsi ( Bean), 182
Cubiceps gracilis (Lowe), 155
Cyclothone Goode and Bean, 31
Cyclothonc acclinidens Garman, 35
Cyclothone atraria Gilbert, 36
Cyclothone sp., 33
Cyclothonc canina Gilbert, 32
Cyclothone signuta Garman, 34

678

TT.S. FISH AND WILDLIFE SERVICE

Oyema atrum Giinther, 117

CYBMIDAE, 117

CYNOGLOSSIDAE, 196

Danaphos oculatus (Garrnan), 39

DERICHTHYIDAE, 116

Derichthys serpentinus Gill, 116

Desmodema polystictum (Ogilby), 132

Diaphus andersoni Tfining ?, 79

Diaphus fulgens Brauer, 77

Diaphus protoculus Gilbert, 78

Diaphus theta Eigenmann and Eigenmann, 76

Diogenichthys atlanticus (Tuning), 69

Diogenichthys laternatus (Garrnan), 70

Diplophos sp., 37

Ditropichthys sp., 63

Dolichopteryx lo-ngipes ( Vaillant), 22

ELASMOBRANCHII, 1-3

Electrons, rissoi (Cocco), 66

ENGRAULIDAE, 5

Engraulis mordax Girard, 5

Eopsetta jordam (Loekington), 195

Evermannella indica Brauer, 114

EVERMANNELLIDAE, 114

Flagellostomias boureei Zugmayer, 50

GADIDAE, 127

GEMPYLIDAE, 161

Gempylus serpens Cuvier, 162

GIGANTURIDAE, 61

GIGAXTUROIDEA, 61

Glyptocephalus zachirus Loekington, 194

GOBIIDAE, 182-183

Gobiidae, unidentified, 183

Gonichthys tenuiculus (Garman), 73

Gonostoma atlanticum Norman ?, 29

Gonostoma ebelingi Grey, 30

GONOSTOMATIDAE, 29-45

HETEROSOMATA, 188-196

Hierops crockeri (Bolin),65

Holorhinus califomious (Gill), 2

Holtbyrnia macrops Maul ?, 11

Holtbyrnia sp. 12

Howella brodiei (Ogilby) ?, 152

Bygophum sp., 67

Hypsoblennius gentilis (Girard), 186

Ichthyococcus elongatus Imai, 44

Ichthyococcus irregularis Rechnitzer and Bohlke, 45

Icichthys loekingtoni Jordan and Gilbert, 156

IDIACANTHIDAE, 56

Idiacanthus antrostomus Gilbert, 56

INIOMI, 64-115

ISOSPONDYLI, 4-60

Kali sp., 169

Lampadena urophaos Paxton, 82

Lampanyctus idostigma Parr, 92

Lampanyctus niger Giinther, 93

Lampanyctus niger Giinther ?, 94

Lampanyctus parricauda Parr, 97

Lampanyctus regalia (Gilbert), 91

Lampanyctus ritteri Gilbert, 90

Lampanyctus sp. (no pectorals) , 98

Lampanyctus sp., 99

Lampanyctus spp., unidentified, 100

Lampanyctus steinbecki Bolin, 95

Lampanyctus tcnuiformcs (Brauer), 96

Lampanyctus (Triphoturus) mexicumis (Gilbert), 87

Lampanyctus (Triphoturus) microchir Gilbert, 89

Lampanyctus (Triphoturus) nigresccns Brauer, 88

Lcpidophanes pyrosobolus (Alcock), 102

Lepidopus xantusi Goode and Bean, 162

Leptostomias sp., 48

Lestidium ringens (Jordan and Gilbert), 107

Leuroglossus stilbius Gilbert, 16

Lobianchia gemcllari (Cocco), 75

LOPHOBRANCHII, 131

LOPHOTIDAE, 134

Lophotus sp., 134

LYOMERI, 61

Macroparalcpis macrurus Ege, 109

Macropinna microstoma Chapman, 21

MACROURIDAE, 128-130

Macrouridae, unidentified, 129

Macrouridae, unidentified, 130

MALACOSTEIDAE, 59

Melamphaes acanthomas Ebeling, 139

Melamphaes indicus Ebeling, 140

Melamphaes laeviceps Ebeling, 141

Melamphaes longivelis Parr, 142

Melamphaes lugubris Gilbert, 143

Melamphaes tnacrocephalux Parr, 144

Melamphaes parvus Ebeling, 145

Melamphaes spp., 147

Melamphaes suborbitalis (Gill), 146

MELAMPHAIDAE, 135-147

Melanonus zugmayeri Norman ?, 126

Melanostigma pammelas Gilbert, 187

M elanostomias ratdiviae Brauer, 51

MELANOSTOMIATIDAE, 48-55

Melanostomiatidae, unidentified, 55

Merluccius productus (Ayres), 127

Microstoma microstoma (Risso), 15

Microstomus paoiftous (Loekington), 193

Mirorictus taaningi Parr, 10

Mola mola (Linnaeus), 197

MOLIDAE, 197

MONOGNATHIDAE, 62

Monognath us sp., 62

MORIDAE, 126

MYCTOPHIDAE, 65-105

Myctophidae, unidentified, 105

Myctophum nitidulum Garman, 72

MYLIOBATIDAE, 2

Nansenia sp., 13

NEMICHTHYIC-AE, 119-121

Nemichthyidae, unidentified, 121

Nemichthys scotopaceus Richardson, 120

NEOSCOPELIDAE, 64

Notolepis rissoi (Bonaparte), 108

Notolychnus vaMiviae (Brauer), 81

Notoscopelus resplendens Richardson, 104

One>irodes acanthais (Gilbert) ?, 200

PELAGIC FISHES, CALIFORNIA CURRENT AREA

679

Oneirodes eschrichtii Liitken, 198

Oneirodes eschrichtii Liitken ?, 199

ONBIRODIDAB, 198-202

Oneirodidae, unidentified, 202

OPHICHTHYIDAE, 124

Ophichthyidae, unidentified, 124

OPISTHOPROCTIDAB, 21-22

Opostomias mitsuii Imai, 49

Palometa simillima (Ayres), 157

PARALEPIDIDAE, 106-109

Parvilux ingens Hubbs and Wisner, 101

PEDICULATI, 198-202

Pellisolus facilis Parr, 9

PERCOMORPHI, 149-187

Photonectes margarita (Goode and Bean), 52

PLECTOGNATHI, 197

PLEURONECTIDAE, 193-195

Porichthys notatus Girard, 184

Porichthys sp., 185

Poromitra erassiceps (Gunther), 136

Poromitra sp., 137

Prionace glauca (Linnaeus), 1

Pseudoscopelus scriptus Liitken, 170

Pteraclis velifera (Pallas) ?, 160

Roncador stearnsi (Steindachner), 166

Sagamichthys abei Parr, 8

Sarda Uneolata (Girard), 163

Sardinops caerulea (Girard), 4

SCIAENIDAE, 165-166

Scomber japonicus (Houttuyn), 164

SCOMBERESOCIDAE, 125

SCOMBRIDAE, 163-164

SCOPELAROHIDAE, 110-113

Scopelarchus yuentheri Alcock, 112

Scopelarchus nicholsi (Parr), 111

Scopelarchus sp., 113

Scopelengys tristis Alcoek, 64

Scopeloberyx robustus (Gunther), 138

Scopelogadus mizolepis bispinosis (Gilbert), 135

SCORPAENIDAE, 171-178

SEARSIDAE, 8-12

Sebastsdes diploproa (Gilbert), 173

Sebastodes goodei Eigenmann and Eigenmann, 176

Sebastodes jordani (Gilbert), 177

Sebastodes prorigcr (Jordan and Gilbert) ?, 175

Sebastodes saxicola (Gilbert), 174

Sebastodes spp., 178

Sebastolobus alascanus Bean, 171

Sebastolobus altivelis Gilbert, 172

Seriphus politus Ayres, 165

SERRANIDAE, 151

Serranidae, unidentified, 151

SERRIVOMERIDAE, 118

Serrivomcr sector Garman, 118

Sphyraena argentea Girard, 167

SPHYRAENIDAE, 167

Stenobrachius leucopsarus (Eigenmann and Eigenmann),

86
STERNOPTYCHIDAE, 23-28
Sterncptyx diaphana Hermann, 28

Stomias atriventer Garman, 46
Stomias sp., 47
STOMIATIDAE, 46-47
STROMATEIDAE, 155-157
Sudis atrox Rofen, 106

Symbolophorus californiense (Eigenmann and Eigen-
mann), 71
Symphurus atricauda (Jordan and Gilbert), 196
SYNENTOGNATHI, 121
SYNGNATHIDAE, 131

Syngnathus arcta (Jenkins and Evermann), 131
Taaningichthys bathyphilus, (Taning), 83
Taamingichthys minimus (Taning), 84
Taaningichthys spp., 85
Tactostoma macropus Bolin, 53
Talismania bifurcata (Parr), 7

Tarletonbeania crenularis (Jordan and Gilbert), 74
TETRAGONURIDAE, 158
Tetragonurus cuvieri Risso, 158
TORPEDINIDAE, 3
Torpedo californica Ayres, 3
TRACHIPTERIDAE, 132-133
Trachipterus t. altivelis Kner, 133
TRICHIURIDAE, 162

V 'alenciennellus tripunctulatus (Esmark) ?, 38
Vinoiguerria lucetia (Garman), 41
Vinciguerria nimbaria (Jordan and Williams), 40
Vinciguerria poweriae (Coceo). 42
Vinciguerria sp., 43
ZANIOLEPIDAE, 180
Zaniolepis frenata Eigenmann ?, 180
ZOARCHIDAE, 187

ACKNOWLEDGMENTS

Many individuals, institutions, and agencies co-
operated in this survey. Much effort and time
were expended by staff members of the Bureau of
Commercial Fisheries Biological Laboratory,
Brunswick, Ga., and Tropical Atlantic Biological
Laboratory, Miami, Fla. The following individ-
uals identified specimens or furnished information
on taxonomy of various species: Alfred W.
Ebeling, University of California, Santa Barbara ;
John E. Fitch, California Department of Fish and
Game; Robert H. Gibbs, Jr., and Leonard P.
Schultz, U.S. National Museum; Carl L. Hubbs,
Bert N. Kobayashi, Grace L. Orton, Richard H.
Rosenblatt, Phillip R. Sloan, and Robert L. Wis-
ner, Scripps Institution of Oceanography ; Robert
J. Lavenberg, Los Angeles County Museum; G.
E. Maul, Museu Municipal do Funchal ; Giles W.
Mead, Museum of Comparative Zoology; John R.
Paxton, University of Southern California;
Robert R. Rofen, Stockton Aquatic Research In-
stitute; Daniel M. Cohen and Bruce B. Collette,
Bureau of Commercial Fisheries Ichthyological

680

U.S. FISH AND WILDLIFE SERVICE

Laboratory, Washington, D.C. ; Paul Struhsaker,
Bureau of Commercial Fisheries Exploratory
Fishing Base, Brunswick, Ga. ; and Elbert H.
Ahlstrom and H. Geoffrey Moser, Bureau of
Commercial Fisheries California Current Re-
sources Laboratory, La Jolla, Calif. Collecting
assistance was provided by Richard L. McNeely,
Bureau of Commercial Fisheries Exploratory
Fishing Base, Seattle, Wash. We wish to credit
the following for illustrations used in this pub-
lication : George Mattson, Bureau of Commercial
Fisheries, California Current Resources Labora-
tory, La Jolla, Calif, (figs. 9, 10, 11, 12, 18, and
20) ; Grady W. Reinert, Bureau of Commercial
Fisheries, Tropical Atlantic Biological Labora-
tory, Miami, Fla. (figs. 3, 17, and 24) ; Robert C.
Counts, Bureau of Commercial Fisheries, Cali-
fornia Current Resources Laboratory, La Jolla,
Calif, (figs. 4 and 5) ; and James E. Ruppert,
Scripps Institution of Oceanography (figs. 7, 19,
and 28).

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1960. The distribution of animals in the Eastern
North Pacific and its relationship to physical and
chemical conditions. Univ. Wash. Dep. Oceanogr.,
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1958. A description of a new species of stomiatid
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1934. Deep-sea fishes of the Bermuda Oceanographic
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1939. Deep-sea fishes of the Bermuda Oceanographic
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1951. The ceratioid fishes, ontogeny, taxonomy, dis-
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1960. Scripps tuna oceanography research (STOR)

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Scripps Inst. Oceanogr., SIO Ref. 60-50, 83 pp.
Bolin, Rolf.

1959. Iniomi Myctophidae from the "Michael Sars"
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N. Atl. Deep Sea Exped. 1910, 4, pt. 2(7) : 1-45.

Bradbury, Margabet G., and Daniel M. Cohen.

1957. An illustration and a new record of the North
Pacific bathypelagic fish Macropinna microstoma.
Stanford Ichthyol. Bull. 7(3): 57-59.

Chapman, Wilbert McLeod.

1939. Eleven new species and three new genera of
oceanic fishes collected by the International Fish-
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Clarke, Wm. D.

1963. Field data for the Isaacs-Kidd midwater
trawl collections of Scripps Institution of Oceanog-
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Cohen, Daniel M.

1958. Nansenia Candida, a new species of argentinid
fish from the North Pacific, with notes on other
species of Nansenia. Stanford Ichthyol. Bull.
7(3) : 52-57.

Ebeling, Alfred W.

1962. Melamphaidae I. Systematics and zoogeog-
raphy of the species in the bathypelagic fish genus,
Melamphaes Giinther. Dana Rep. 58, 164 p.

Ebeling, Alfred W., and Walter H. Weed III.

1963. Melamphaidae II. Systematics and distribu-
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Scopclogadus Vaillant. Dana Rep. 60, 58 p.

Ege, Vilh.

1934. The genus Stomias Cuv., taxonomy and bio-
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1948. Chauliodu* Schn., bathypelagic genus of
fishes. A systematic, phylogenetic and geographical
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1957. Paralepididae II (Macroparalepis) . Taxon-
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Fraser-Brunner, A.

1949. A classification of the fishes of the family
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Gilbert, Charles Henry.

1905. The aquatic resources of the Hawaiian Is-
lands. Part II, Section II — The deep-sea fishes.
U.S. Fish Comm., Bull. 23, pt. 2: 575-765.
Grey, Mabion.

1955. Notes on a collection of Bermuda deep-sea
fishes. Fieldiana : Zool. 37 : 265-302.

1960. A preliminary review of the family Gonosto-
matidae, with a key to the genera and the descrip-
tion of a new species from the tropical Pacific.
Mus. Comp. Zool., Bull. 122(2) : 57-125.

PELAGIC FISHES, CALIFORNIA CURRENT AREA

681

Harry, Robert R.

1951. Deep-sea fishes of the Bermuda Oceanographic
Expeditions. Family Paralepididae. Zoologica 36,
pt. 1 (2) : 17-35.
1953. Studies on the bathypelagic fishes of the family
Paralepididae (order Iniomi). 2. A revision of
the North Pacific species. Acad. Natur. Sci.,
Philadelphia, Proc. 105 : 169-230.
1953. Studies on the bathypelagic fishes of the family
Paralepididae. 1. Survey of the genera. Pac.
Sci. 7 (2) : 219-249.
Heller, Edmund, and Robert Evans Snodgbass.

1903. Papers from the Hopkins Stanford Galapagos
Expedition, 1898-1899. XV. New Fishes. Wash.
Acad. Sci., Proc. 5: 189-229.
Herre, Albert W., and Earl S. Herald.

1951. Noteworthy additions to the Philippine fish
fauna with descriptions of a new genus and species.
Philippine J. Sci. 79(3) : 309-340.

Jespersen, P., and A. Vedel TAning.

1926. Mediterranean Sternoptychidae. Rep. Danish

Oceanogr. Exped. 1908-1910 Mediter. and adj. seas,

2(9) (biology), A. 12, 59 p.
King, Joseph E., and Robert T. B. Ivebsen.

1962. Midwater trawling for forage organisms in
the central Pacific, 1951-1956. U.S. Fish. Wildl.
Serv., Fish. Bull. 62: 267-321.

Koefoed, Einab.

1952. Zeomorphi, Percomophi, Plectognathi from
the "Michael Sars" North Atlantic deep-sea ex-
pedition 1910. Rep. Sci. Results "Michael Sars"
North Atl. Deep-Sea Exped. 1910, 4, pt. 2(2) : 1-27.

Manbueti, Romeo.

1963. Symbiotic behavior between small fishes and
jellyfishes, with new data on that between the
stromateid, Peprilus alepidotus, and the scypho-
medusa, Chrysaora quinquecirrha. Copeia 1963(1) :
40-80.

Marshall, N. B.

1955. Alepisauroid fishes. Discovery Rep. 27 :303-
336.
Maul, G. E.

1949. Alguns peixes notaveis. Mus. Munic. Funchal,

Bol. 4, art. 11 : 22-42.
1957. Further additions to the previously revised
family Searsidae. Mus. Munic. Funchal, Bol. 10,
art. 25 : 5-21.
1959. On a specimen of Bathytoco nigricans Good
and Bean taken from the stomach of Aphanopus
cwrbo. Bocagiana 4, 8 p.
McNeely, Richard J.

1963. Development of the John N. Cobb pelagic trawl :
a progress report. Com. Fish. Rev. 25(7) : 17-27.

Morrow, James E., Jr.

1961. Taxonomy of the deep-sea fishes of the genus
Chauliodus. Mus. Comp. Zool., Bull 25(9) : 249-294.

Ml'KHACHEVA, V. A.

1964. Ovidovom sostave roda Cyolothone (Pisces,
Gonostomatidae) v Tikhom okeane. (Species com-

position of the genus Cyolothone (Pisces, Gonosto-
matidae) in the Pacific Ocean.) Tr. Inst. Okeanol.
73 : 93-138.

Nichols, John Tbeadwell, and John Cushman Mubphy.
1944. A collection of fishes from the Panama Bight,
Pacific Ocean. Amer. Mus. Natur. Hist., Bull. 83,
art. 4 : 217-260.

Ogilby, J. Douglas.

1898. Additions to the fauna of Lord Howe Island.
Linnean Soc. New South Wales, Proc. 23: 734-745.

Parr, Albert Eide.

1933. Scientific results of the third oceanographic
expedition of the "Pawnee" 1927. Deep-sea Bery-
comorphi and Percomorphi from the waters around
the Bahama and Bermuda Islands. Bingham
Oceanogr. Collect., Bull. 3, art. 6. 51 p.

1960. The fishes of the family Searsidae. Dana Rep.
51, 109 p.

Paxton, John R.

1963. A new lanternfish (family Myctophidae) of
the genus Lampadcna from the Eastern Pacific
Ocean. Copeia 1963 (1) : 29-33.
Rechnitzer. Andreas B., and James Bohlke.

1958. Ichthyococcus irregularis, a new gonostomat-
ine fish from the Eastern Pacific. Copeia 1958
(1) : 10-15.
Regan, C. Tate, and Ethelwynn Tbewavas.

1929. The fishes of the families Astronesthidae and
Chauliodontidae. Danish "Dana" — Exped., 1920-
22, 5 : 1-39.
Rofen, Robert R.

1963. Diagnoses of new genera and species of alepi-
sauroid fishes of the family Paralepididae. Aqua-
tica 2 : 1-5.
Sanzo, Luigi.

1918. Stadi larvali di Paralepis hyalina C.V. R.
Comitato Talassografico Italiano, Mem. 59:1-7.
Schultz, Leonard P.

1937. Reports on the collections obtained by the first
Johnson-Smithsonian deep-sea expedition to the
Puerto Rican Deep. A new species of deep-sea fish,
Argyropelecus antrorsospinus, of the family Ster-
noptichidae. Smithsonian Misc. Collect. 91 : 1-27.

1961. Revision of the marine silver hatchetfishes
(family Sternoptychidae). U.S. Nat. Mus., Proc.
112 (3449) : 587-649.

Scbipps Institution of Oceanography and U.S. Fish
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1952. Station positions of the California Coopera-
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16 pp.
Wisner, Robert L.

1962. Midwater trawl surveys. Limnol. Oceanogr.
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1963. Lampanyctus hubbsi, a new myctophid fish
from the East-Central Tropical Pacific Ocean, with
notes on the related, sympatric Eastern Pacific
species, h. omostigma and L. pnrvicauda. Copeia
1963 (1) : 16-23.

682

U.S. FISH AND WILDLIFE SERVICE

COMPARISON OF TWO METHODS OF N-ETHYLCARBAZOLE
CARBOHYDRATE ANALYSIS »

By Kenneth T. Marvin and Raphael R. Proctor Jr., (Chemists)
Bureau of Commercial Fisheries Biological Laboratory, Galveston, Tex.

Two currently used N-ethylcarbazole (NEC)
methods for determining the amount of dissolved
substances in sea water which respond to the NEC
reagent and which will be referred to here as
"carbohydrates," are the original one described
by Erdman and Little 2 and the modification de-
scribed by Zein-Eldin and May (1958). It has
been assumed by many investigators that those
methods give comparable results when used to es-
timate the amount of carbohydrates in water.
Recently, however, data obtained through both
methods at the Bureau of Commercial Fisheries
Biological Laboratory in Galveston, Tex., sug-
gested that their corresponding estimates differ
significantly. This difference prompted us to de-
termine experimentally if the two methods yield
the same results when used to analyze the carbo-
hydrate content of aliquots from the same sample.

The original method described by Erdman and
Little consists of adding the NEC reagent ( 1 g./l.
of 36 N H2S04) to the sample in one step, warming
the mixture in a water bath, and then comparing
color density with that of similarly treated arabi-
nose (D-(-) -Arabinose) standards. This proce-
dure will be called the "one-step" method. The
method described by Zein-Eldin and May is the
same as the above except that the NEC reagent is
added in two steps. We will therefore refer to this
procedure as the "two-step" method. Results of
both procedures are based on the density of color

Note. — Approved for publication May 1. 1965.

1 Contribution No. 195, Bureau of Commercial Fisheries Bio-
logical Laboratory, Galveston, Tex.

2 Erdman, J. G. and A. B. Little. 1950. Analysis of marine
coastal and estuarine waters, 50 pp. Multiple fellowship of
Gulf Research and Development Co., Mellon Institute, Pitts-
burgh, Pa. (Unpublished.)

development when NEC reagent reacts with car-
bohydrates. Units are expressed in mg. equival-
ents of arabinose.

We compared the two methods by analyzing
carbohydrate determinations obtained routinely
from many samples with each procedure. The
one-step method yielded significantly higher
results (table 1).

Table 1. — Concentration of carbohydrates in samples of
water collected from Galveston Island's East Lagoon during
the period February-August, 1963

[Units are mg./l. of arabinose equivalents]

Date, 1963

Feb. 16.
Feb. 19..
Mar. 1...
Mar. 12..
Mar. 15..
Mar. 19..
Mar. 22..
Mar. 26..
Mar. 29..
Apr. 2...
Apr. 9...
Apr. 23..
May 8...
May 10..
May 14. .
May 17..
May 21..
May 24..
May 28..
May 31..
June 4..
June 7. .
June 11.

Method

One-
step

Mg./l.
4.15
4.00
3.80
4.55
4.35
3.65
3.50
3.20
2.55
3.11
5.14
3.17
4.06
3.43
3.91
3.94
3.28
2.31
3.03
3.60
4.13
3.33
4.58

Two-
step

Mg./l.
1.06

.61
1.98
1.71
2.61

.78
1.15

.85

.73
1.86
3.01
2.33
1.98
2.15
2.36
2.02
2.13
2 24
L71
2.25
2.70
1.99
2.63

Date,
1963

6-14

6-18

6-21

6-25

6-28

7-2

7-5

7-9

7-12

7-16

7-19

7-23

7-26

7-30

8-2

8-7

8-9

8-13

8-16

8-20

8-21

8-22

Method

One-
step

Mg./l.
3.80
4.71
3.92
3.66
4.64
5.69
5.85
7.21
5.07
4.28
5.36
4.28
6.50
4.71
5.07
5,07
7.85
4.57
5.00
4.07
2.55
3.60

Two-
step

Mg./l.
2.27
3.76
2.32
1.78
3.25
3.90
3.70
3.18
3.24
3.03
4.45
2.58
3.48
3.15
2.94
2.18
3.03
2.67
3.51
2.70
2.47
2.36

Upon investigating the reason for the differences
noted between estimates secured by the two meth-
ods, we found that the color density resulting from
interacting NEC and carbohydrates in natural
waters varied only slightly with the method used.
However, when the NEC reagent was added to
standard or calibration samples that consisted of

FISHERY BULLETIN: VOLUME 65, NO. 3,

683

known concentrates of arabinose in distilled or
saline water, the resulting color density varied
with the method used. The variation was such

♦_

ONE-STEP METHOD

Logoon Sample-^

t^~fl ___---""" _. 4mgVL~-| •

— . - " 3mg./L.-.

.^-> — o " * a

C~-> , =^ ?mg/l -,

■"■ ♦ ■

. Lllfti/'-— '-' — t

^^♦-. * ' Omg,/L y

TWO-STEP METHOD

— i 1 1 r

0 20 «0 60 80 100 120 l«0 160 180

RATE OF CARBAZ0LE REAGENT DELIVERY (SEC/27 ML)

Figure 1. — Color density values obtained for six standard
water samples and for one sample taken from Galveston
Island's East Lagoon using two methods of carbohydrate
analysis at five rates of reagent addition.

that estimates by the one-step method were higher
than those obtained by the two-step method. We
also found that the precision of estimates by either
method is reduced if the reagent is added at a rate
faster than about 27 ml. — the amount required by
each procedure — per 65 seconds.

These conclusions become apparent from figure
1, which shows the raw data used to estimate the
carbohydrate concentration in a water sample by
both methods at various rates of reagent addition.
If we consider only those portions of the curves
from the 65-second addition rate and beyond, it
can be seen that response of the carbohydrate
in the sample to the NEC reagent corresponds to
that of 6 to 7 mg./l. of arabinose by the one-step
method, and 2.5 to 3 mg./l. by the two-step method.
If the entire curves are considered, the sample
estimates of carbohydrate concentration vary from
about 0.3 to 7.0 mg./l. depending on the method
used and also on the rate of reagent addition. The
erratic results recorded when the reagent deliver}'
rate was less than about 27 ml. per 65 seconds seem
to be characteristic of both methods.

LITERATURE CITED

Zein-Eldin, Zoula P., and Bii.lje Z. Mat.

1958. Improved N-ethylcarbazole determination of
carbohydrates with emphasis on sea water samples.
Anal. Chem. 30(12) : 1935-1941.

()S4

U.S. FISH AND WILDLIFE SERVICE

RAPID METHOD FOR DETERMINING WATER CONTENT IN OYSTER TISSUE

By Thomas C. Carver, Jr., Fishery Biologist (Research)1
Bureau of Commercial Fisheries Biological Laboratory, Oxford, Md.

Medcof (1941) defined Condition Index (CI)
as the ratio of the dry weight of the meat to the
volume of the space between the valves X 1000.
To dry the meat, Engle (1958) used 72 hours ex-
posure at 90° C. in a convection-type oven. This
will reduce a 25 g. sample to constant weight ; how-
ever, it is frequently desirable to avoid the 72-hour
waiting period.

Korringa (1956) reported a method by which
the water content of oyster meats could be deter-
mined volumetrically using toluene distillation.
The homogenized sample was placed in a flask and
covered with toluene. The flask was connected to
a condenser fitted with a distillation trap and main-
tained at 100° C. for 1 hour. The volume of water
collected was measured and converted to weight.
The total time required was about 1 hour. We
were unable to get the reproducible accuracy de-
sired because of the tenacity with which small
droplets of water adhered to the sides of the con-
denser and fittings. To overcome this problem we
devised a gravimetric adaptation of Korringa's
method which eliminates the condenser and its as-
sociated problems and in which the weight of water
is determined directly. This adaptation is dis-
cussed below.

Figure 1 shows all major components of the ap-
paratus. The function of the intake drying

NOrB. — Approved for publication April 13, 1965.

1 The present address of Thomas C. Carver, Jr., is Pesticide
Registration Review Staff, Patuxent Wildlife Research Center,
Laurel, Md.

tubes is to provide an atmosphere free of moisture.
A 10 g. sample of homogenized oyster tissue is
covered with toluene and heated to 100° C. for 45
minutes. The water vapor is collected in the tared
outlet drying tubes. All tubes contain the drying
agent, calcium chloride. Plastic check valves con-
trol direction of water vapor flow. The number of
drying tubes needed can be determined by a trial
run in which weights of the individual tubes are
recorded. The last tube in direction of flow on
both sides of the flask should not show a weight
increase. In practice, once the proper number of
tubes is determined, the tubes can be weighed as
a unit. Suction should be applied very gently.
With this method, we have been able to produce the
same accuracy in 45 minutes that requires 72 hours
in a conventional drying oven.

LITERATURE CITED

Engle, James B.

1958. The seasonal significance of total solids of
oysters in commercial exploitation. Proc. Nat.
Shellfish. Ass. 48 : 72-78.
Korringa, P.

1955. Qualitatsbestimmungen an Miesmuseheln und
Austern. Arch, Fischereiwiss, 6 : 189-193. ( Trans-
lation by N. M. Carter. 1956. Quality determina-
tions of mussels (Mytilus edulis) and oysters.
Fish. Res. B. Can., Transl. Ser. 76.)
Medcof, J. C.

1941. The influence of temperature and salinity on
the condition of oysters (Ostrea virginicus). J.
Fish. Res. B. Can. 3: 253-257.

FISHERY BULLETIN: VOLUME 65, NO. 3

685

'»TA

C¥>

1. PLASTIC CHECK VALVE

2. PLASTIC DRYING TUBE

3. TO SUCTION CONNECTION

HEAT SOURCE

Fioube 1. — Diagram of extraction apparatus.

()S(i

U.S. FISH AND WILDLIFE SERVICE

U.S. GOVERNMENT PRINTING OFFICE : 1966 O — 795-358

INDEX TO VOLUME 65

Aethoprora elucens 658,

Agonidae spp

Alepocephalus tenebrosus

Alewife (Alosa pseudoharengus)

Allen, Donald M

Allot riognathi

Alosa pseudoharengus

Anaeanthini

Anchovies (Engraulidae)

Anchovy, northern (Engraulis mordax)

633, 634, 635,

Anoplogaster cornuta

Anoplopoma fimbria

Anotopterus pharao

Aplodinotus grunniens 490,

Apodes

Apristurus. 581-597, 611-615, 619,

allanlicus

brunneus 581,

milieus 613,

laurussoni 615,

profundorum 612,

riveri 582, 589, 613-614,

Archosargus probalocephalus

Argentina sialis

Argentine, Pacific {Argentina sialis)

Argentinidae

Argyropelecus:

hawaicnsis 641-

intermedius

lychnus

pacificus 640-

spp

Ariosoma gilberli

Aristostomias scintillans

Astronesthidae

Alelomyeterus

Avicennia nitida

Avoeeltina bowersi 667,

Page
659, 678
676, 678
635, 678
... 490
449-459
668, 678

490

668, 678

635, 679
. 632,

636, 679
671,678
676, 678
667, 678
491, 494
667, 67S
621, 622

613
589, 592
621, 622
621, 622
621, 622
621, 622
370-373
638, 678
638, 678
638, 678

643, 678
641, 67S
641, 678
-641, 678
643, 678
667, 678
653, 67S
652, 678
583, 591
377

669, 678

Bairdiella chrysura 378

Baptist, John P 427-436

Barracuda, Pacific (Sphyraena argentea) 674, 680

Barracudas (Sphyraenidae) 674, 680

Barreleye (Macropinna microstoma) 639, 640, 679

Barreleyes (Opisthoproctidae) 640, 6S0

Bass, white (Roccus chrysops) 490

Basses, sea (Serranidae) 671, 680

Bathophilus flemingi 650, 651, 678

i Fishery Bulletin Volume 65. No. 1, pp. 1-298 has its own index.

Page

Bathylaco nigricans 654, 678

Bat hvlaconidae 654, 678

Bathylagidae 638-640, 678

Bathylagus:

miller i 638, 678

ochotensis 638, 678

pacificus 638, 678

wesethi 638, 678

Bathyleplus lisae 654, 678

Batrachoididae 676, 678

Bay of Fundy 299

Benthalbella dentata 665, 666, 67S

Benthosema suborbitalc 656, 678

Berry, Frederick H 625-682

Berycomorphi 668-671, 678

Bibliographies (and lists) :

alphabetical, pelagic fishes, California Current

Area 678-680

annotated, pelagic fishes, California Current

Area 634-677

Brama japonica 673, 67S

Bothus leopardinus • ■ ■ 677, 678

Bothidae 676-677. 67S

Borostomias panamensis 651, 652, 678

Bonito, California (Sarda lineolata) 673, 680

Bodola, Anthony ■ 391-425

Blenny, bay (Hypsoblennius gentilis) 676, 679

Blenniidae 676, 678

Blennies, combtooth (Blenniidae) 676, 678

Bramidae 673, 678

Breams, sea (Bramidae) 673, 67S

Brevoortia:

gunteri 37a

patronus 375, 376

smithi 375, 376

lyrannus 4.33

Bureau of Commercial Fisheries:

Biological Field Station, Miami, Fla 449

Biological Laboratory :

Ann Arbor, Mich 489

Auke Bay, Alaska 461, 495, 555

Galveston, Tex ... 313, 437, 683

Honolulu, Hawaii 479

Oxford, Md 685

Seattle, Wash 381

Woods Hole, Mass 299. 527

Biological Station, St. Petersburg Beach, Fla. . 369
California Current Resources Laboratory, La

Jolla, Calif 625

Columbia Fishery Program Office, Portland,

Oreg 339

6S7

Pago

Ichthyologies] Field Station, Stanford, Calif. . 581

Radiobiological Laboratory, Beaufort, N.C . . . 427

Butterfishes (Stromateidae) 673, 680

CalCOFI stations 629-631

California Current fishes 625 -682

Callinectes sapidus. . . 372, 376, 428, 429, 430, 431, 433, 434

Carangidae 671, 678

Caranx hippos 370,371,372,373,374,375,376

Carbohydrate ■ • ■ <|S:;

Carcharhinidae ■ 635, 67s

Carcharhinus leucas 593

( 'aristius:

macropus 671, 678

maderensis 671,678

Carver, Thomas C, Jr 685-686

i ', phaloscyllium uter ■ 581, 59 1

( 'eratoscopelus tovmsendi 664. 678

( letomimidae 655, 678

Cetunculi 655,678

Chaenophryne parviconus. . . . .... 677, 67S

Chauliodontidae. . . ■ 652,678

Chauliodus macouni. . 649,652-653

Cheilodipteridae 671, 67S

< 'hiasmodon niger 674, 678

Chilipepper (Sebastodes goodei) 676, 680

Cigarfish, longfin (Cubiceps gracilis) 673, 678

Cisco (Coregonus artedi) 489

Citharichthys:

sordidus 676, 678

spp 677,678

stigmaeus 677, 678

xanlhostigma 677, 678

Clam, hiirdi Mercenaria mercenaries) 430-432

Clupeidae 635, 678

Cobb Mark-II pelagic trawl 625

Codfishes and hakes I Gadidae) 668, 679

Collapsible midwater beam trawl 625, 626, 629, 631

Cololabis saira : . . . 668, 678

Combfish, shortspine (Zaniolepis frenata) 676, 680

Combfisb.es (Zaniolepidae) 676, 680

Congridae spp 667, 678

Conoporoderma

african uum 584

spp 582,584

Cook, Harry L 437-447

( 'oregonus:

artedi 489

clupeaformis 489

Coryphaena hippurus 673, 678

( 'oryphcu noidi s acroh pis 668, 678

Coryphopterus nicholsi 675, 676, 67n

Costello, T.J . 149-459

i 'rah. blue {Callinectes sapidus) 372

376, 128,429,430,431,433, 134

Crassostrea virginica 376,434 435,685 686

( Y.'st fishes (Lophotus spp.) 668, 669, 679

Croaker: Pa«

Atlantic (Micropogon undulatus) 428, 433

spotfin (Roncador stearnsi) 674, 680

Cubiceps gracilis 673, 678

Cutiassfishes (Trichiuridae) 673, 680

Ci/clolhone:

acclinidens 647, 678

atraria 647, 678

canina 646-647,678

signata . . 647, 67*

spp 647, 678

Cyema atrum 667, 679

Cynoglossidae 677, 679

Cynoscion ;

arenarius 379. 372

nebulosus 370,372

Cyprinodon variegatus 430

Danaphos oculatus 648, 649, 679

D-(-)-Arabinose 683

l)i richthys serpenlinus 667, 669, 679

Desmodema polystictum . 668, 669, 679

I>iii phus:

andersoni 658, 659, 679

fulgens 657, 679

protoculus 659, 679

theta 657, 679

Diapterus plumieri 370, 371, 372, 373. :;74. 375, 376

Diogenichthys:

atlanticus 656, 679

laternatus 656, 679

Diplanthera wrighlii 377

Diplophos spp 647, 679

Ditropichthys spp 655, 679

Dolichopteryx longipes 640. 679

Dolphin (Coryphaena hippurus) 673, 678

Dorosoma cepedianum .... 391-425, 490, 491, 492. 493, 494
Drum:

black (Pogonias cromis)

371, 372. 373,374,

freshwater (Aplodinotus grunniens) 490,

red ( Sciaenops ocellata)

371, 372, 373, 374,

star {Slellifcr liiiitrolnliis). . .

1 Irums (Sciaenidae)

Duke, Thomas W

. 370,
375, 376
491, 494
37(1,
375, 376
433
674, 680
427-436

E
Eel, long-necked (Derichlhys strpnilinits) . . 667,669,679

Eelpouts (Zoarchidae) 676, 680

Eels:

eonner (Congridae) 667, 668

snake (Ophichthidaei 667, 680

snipe (Nemichthyidae) 667. 678

Elasmobranchii 635, 679

El clrona rissoi 656, 679

Engraulidae 635, 679

Engraulis mordax 632. 633, 63 I. 635, 636, 679

Kopsi /In junliiiii . 672, 677, 679

fiNN

Ksi uarine:

engineering
fishes . . .

in Florid:]

nurseries:

engineering disruption of 377-

pollution of

Etmopterus

Eucinostomus:

argenleus 370, 371, 372, 373, 374, 37"),

gula 370, 371, 372, 373, 374, 375,

En rmanndhi indica (566, 667,

Page
369
369

378
377
590

376
376

679

Figaro 590,

Finueane, John II 369

Fisheries, Gulf of Mexico 369-

Fish nurseries, relation of, to Gulf of Mexico

fisheries 377-

Flagellostomias boureei 650,

Florida:

effect? of dredging and filling

Grounds, Tortugas and Sanibel 449-

Flounder (Paralichthys spp.)

Flounders:

lefteye (Bothidae) 676-677,

righteye (Pleuroncctidae) 677,

Food of young-of-the-year walleyes in Lake Erie . 489

French, Robert R 339

Fundulus heteroclitus

Gulf of Mexico fisheries

Gadidae

Galeus:

arae 608-609,

cadenati n.sp 609-611,

eastmani

hertwigi

jenseni

melastomns

murinus

polli

sauleri

spp 583-611,617,

Gempylus serpens 673,

Georges Bank . . . . 299, 300, 301,

Giganturidae

Gill net mesh curves

Pacific salmon:

pink salmon 381—386,

sockeye salmon 381-382,

chum salmon 381-382,

Glyptocephalus zachirus 672,

Gobies (Gobiidae spp.)

Goby, bluespot (Coryphopterus nicholsi). . . . 675,

Gold 199

Gonichthys tenuiculus

369-
668,

620,
(121).

60S.

619
675,
304,
654,
381

388-
384-
387-
677,
676,
676,
427-
657,

607

379
379

378

679

369
459
433

678
680
-494
-36S
434

379
679

621
621
608
60S
608
621
608
608
60S
621
679
308
679
-390

-390
-390
-390
679
679
678
-436
679

(ionoslomu Page

atlanticum 643, 644, 679

ebelingi 643,644,679

< Irass :

cord (Syringodium filiforme) 377

manatee (Sir cord grass).

shoal (Diplanthera wrightii) 377

turtle (Thalassia testudinum) 377

( livnadiers (Macrouridae) 668, 679

I lake-
Pacific (Merluccius productus) 634,

silver (Merluccius hilinraris)

Hakes (Sec codfishes and hakes).

Halaeluriis:

bivius 582,618,621,

chilemis 582,618,621,

spp 582, 615-618, 621,

Haploblepharus

Harengula pcnsacolae

Harris River

Hartmah, Wilbur L 555-

Heard, William R 555-

Hemiscyllium

Herring, lake (See Cisco).

Herrings (Clupeidae)__ ■ 635,

Heterosomata 676-677,

Hierops crockeri 651, 655,

Holorhinus californicus 635, 636,

Holtbyrnia:

macrops 636, 637,

spp 636, 638,

Hoss, Donald E 427-

Howella brodiei 671,

Hydrobiology, Franz Theodore Stone Institute of,

Ohio State University, Put-in-Bay, Ohio

Hydrology of Tampa Bay

Hijgophum spp 651, 656,

Hypsoblennius gentilis 676,

I
Ichthyococcus:

elongatus 648, 649, 679

irregularis 648, 649, 679

Icichlhys lockingtoni , 673, 675, 679

Idiacanthus antrostomus 651, 652, 679

Indian Creek 501

Iniomi 655-667, 679

Isistius 594

668
536

622
622
622
582

377
501
579
579
604

678
679
679
679

679
679
436
675

391
371
679
679

Isospondyli .

635-654. 679

Jack, crevalle (Caranx hippos) 370,

371, 372, 373, 374, 375, 376

Jacks, scads, and pompanos (Carangidae) 671, 678

Jenny, silver (Eucinostomus gula) 370,

371, 372. 37::, 374, 37:.. 376

Jensen, Albeit C 527-554

Juvenile commercial fishes, seasonal and area!

distribution in Tampa Bay 371

689

K PaSe

Kali spp 674,679

Kalsuwonus pelamis 479-488

Key to:

Apristurus, western Atlantic 611-612

Galeus, western Atlantic 608

Scyliorhinidae, western Atlantic 597

Scyliorhinus, western Atlantic 598

Kutkuhn, Joseph H 313-338

Lake Erie walleyes, food 489-494

Lake Erie, western 391

Lampadena urophaos 659, 661, 679

Lampanyctus:

idostigma 662, 663, 679

mexicanus 660, 661, 679

microchir 660, 661, 679

niger 661, 662, 679

nigrescens 660, 661, 679

parvicauda 662, 663, 679

regalis 662, 663, 679

rilleri . . . 660-662,679

spp 662, 679

steinbecki 662, 663, 679

tenuiformes 662, 663, 679

Lanternfishes (Myctophidae) 632, 633, 655-664, 679

Leiostomus xanthurus 370, 371, 372

Lepidophanes pyrosobolus 663, 664, 679

Lepidopus xantusi 673, 675, 679

Leptoslomias spp 650, 679

Lestidium ringens 665, 666, 679

Leuroglossus stilbius 638, 639, 679

Lobianchia gemellari 657, 658, 679

Lophobranchii 668, 679

Lopholus spp 668, 669, 679

Lyomeri . . . 654, 679

MackereJ:

jack (Trachurus symmetricus) 671, 675

Pacific (Scomber japonicus) 673

snake (Gempylus serpens) 673, 675, 679

Spanish (Scomberomorus maculatus) 370

371,372, 373,374,375

Mackerels and tunas (Scombridae) 673, 680

Macroparalepis macrurus 665, 666

Macropinna microstoma , . 639, 640, 679

Macrouridae 668, 679

Malaeosteidae 653, 679

Mangrove:

black (Avicennia nitida) ... -177

red (Rhizophora mangle) '177

Marvin, Kenneth T 683 68 1

McNeil, William J 495-523

Medusafish (Icichthys Inrkinijlimi) 673, 675, 679

Melamphaes:

acanthomas 670, 672, 679

milieus 670, 672, 670

i/ii via j,r ... 670, 672, 679

690

Page

longivelis 670, 672, 679

lugubris 670, 672, 679

macrocephalus 671, 672, 679

parvus 671, 672, 679

spp 671,679

suborbital 671, 672, 679

Mclamphaidae 668-670, 679

Melanonus zugmaytri 668, 669, 679

Mi lanostigma pammelas 676, 679

M elanostomias valdiviae 650, 679

Melanostomiatidae spp 652, 679

Menhaden:

American (See Atlantic menhaden)

Atlantic (Brevoortia tyrannus) 433

finescale (Brevoortia gunteri) 375

largescale (Brevoortia patronus) 375, 376

yellowfin (Brevoortia smithi) 375, 376

M i n nl in beryllina 378

Merct iiuria nu ret nana 430—432

Merluccius:

bilinearis 536

productus 634, 668

Merrill, Arthur S 299-311

M icropogon undulatus 428, 433

Microstoma microstoma 638, 679

Microstomas pacificus 672, 677, 679

Midshipmen i Porichlhys spp.) . 676, 680

Midwater trawls 625-634

Minnow, sheepshead Cyprinodon variegalus 430

Mirorictus taaningi 636, 637, 679

Mojarra:

striped (Diaphiris plumieri) 370,

371, 372, 373, 374, 375, 376

spotfin (Eucinostomus argenteus) 370,

371, 372, 373, 374, 375, 376

Mola mola 677, 679

Molaa (Molidae) 677. 679

Molidae 677, 679

Molluscan growth studies, methodology of. . 299, 303-31 1

Mollusks 299-311

Monognathus spp 654, 679

Moridae 668, 679

M uijil:

cephalus 370, 371, 372, 373, 374, 375. 376

curema 372, 373, 374, 375. 376

trichodon 370, 371, 372, 373, 374. 375. 376

Mullet:

fantail l Mugil trichodon) 370,

371, 372. 37:;. 371. 375, 376
silver (Mugil curema) (See white mullet).
silver (Mugil trichodon) (Sec fantail mullet).

striped I Mugil cephalus) 370,

371.372, :;;:;. 374, 375, 376

white (Mugil curema) 372. 37:;. 374, 375, 376

Mummichog (Fundulus heteroclitus) l;;t

Mustelus nun.-- 529

Myctophidae 632, 6:;:;. 655 664, 67<J

Myctophum nitidulum 657, 679

Mvliobatidae 635, 679

N Pass

Naknek River System 461-478

Nansenia spp 638, 679

Nemichthys scolopaceus 666, 667, 679

Nemichthyidae spp 667, 679

Neoscopelidae 655, 679

N-cthylcarbazole 683

Nichy, Fred E 299-311

Notolcpis rissoi 665, 666, 679

Notolychnus valdiviae 6.59, 671, 679

Notoscopelus resplendens 663, 664, 679

Notropis:

atherinoides 490, 491 . 492, 493, 494

hudsonius 490, 491. 492, 493, 494

Oncorhynchus:

gorbuscha

keta

kisutch

nerka 339-346, 348-368,

tshawytscha

351, 353, 359-360, 361-362,
Out irodes:

acanthias 677,

eschrichtii 677,

Oncirodidae spp

Ophichthyidae spp

Opisthoproctidae

Opostomias mitsuii

Opsanus lau

Orectolobidae

Osmerus mordax

( >yster, American (Crassoslrea virginica)

434-435,
Oyster water content

495-523
495-523
495
461-476
. 340,
365, 495

678, 679
678, 680
677, 680
667, 680
640, 680
650, 680
428-430
582
490
. . 376
685-686
685-686

Palomtta simillima 673, 675, 680

Paralepididae 664-665, 680

Parol iehthys spp 433

Parmaturus:

pilosus 607

xaniurus 607

Parvilux ingens 663, 664, 680

Pearleye, northern (Benthalbella dentata) 665, 67S

Pearleyes (Scopelarchidae) 665, 667, 680

Pecten 301

Pediculati 677, 680

Pelagic fishes:

range extensions 637,

643, 648, 650, 652, 654, 659, 667, 670, 676

survey of 625-682

Pdlisolus facilis 636, 637, 680

Penaeus:

aztecus 314, 326, 374, 438

duorarum 313-338, 437-447, 449-459

setiferus 433-434

Pentanchus:

profundicollis 583

spp 5S3

Perca flavescens

Perch:

silver i Bairdiella chrysura)

.vellow (Perca flavescens)

Percomorphi 671-

/'/ nnpsis omiscomaycus

Perkins, Herbert C

Permit ( Trachinotus falcatus)

371, 372, 373, 374,

Petersen disc

Peterson, Alvin E

Photonectes margarita 650,

Pintarroja (Halaelurus chilcnsis) 582, 618,

Pipefish, snubnose (Syngnathus arcta)

Pipefishes and seahorses (Syngnathidae)

Placopecten magellanicus

Plectognathi

Pleuronectidae

Pogonias cromis 370, 371, 372, 373, 374,

Pomfret (Brama japonica)

Pomfrets (Bramidae)

Pompano:

common (Trachinotus carolinus)

371, 372, 373,

Pacific (Palometa simillima) 673.

Pompanos (See Jacks, scads, and pompanos)

Porichthys spp

Poromilra crassiceps 669,

Posgay, Julius A

Prionace glauca 635,

Pristiophorus:

schroederi

SPP

Proctor, Raphael R., Jr

Prosopium coalteri

Pseudoscopelus scriptus

Pseudolrinkis:

Page
490

acrages . .
niicrodon .
spp

Pleraclis velifera 673,

Queenfish (Seriphus politus) .

378
490

676, 680
490

625-682
370,
375, 376
304
381-390
651, 680
621, 622
668, 680
668, 680
299-311

677, 680
677, 6S0
375, 376
673, 67S

673, 678

370,
374, 375

675, 680

676, 680
670, 680
299-311
636, 680

595
594, 595
683-684
555-579

674, 680

595

583
583

675, 6S0

674, 680

Radioactive gold 427-

Radioactive tracers 427-

Ray, electric, Pacific (Torpedo calif ornica) . . 635, 636,

Rays:

eagle (Myliobatidae) 635,

electric (Torpedinidae) 635,

Rhizophora mangle

Roccus chrysops

Rockfish:

longspine (Sebastolobus allivelis) 674, 675,

shortspine (Sebastolobus alascanus) 674, 675,

436
436
6S0

679
680

;;77
490

680

0.SO

691

Rockfish: Pi>£e

redstripe (Sebastodes proriger) 676, 6s0

shortbelly (Sebastodes jordani) . . 676,680

splitnose (Sebastodes diploproa) 676, 680

stripetail (Sebastodes saxieola) 676, 680

Rock Island Dam fishways, passage of salmon at.. 339

Roncador stearnsi 674, 6S0

Sablefish (Anoplopoma fimbria)

Sagamichthys abei 635,

Salmon:

chinook (Oncorhynchus tshawytscha)

351-353, 359-360, 361-362,

spring 339,

summer 339,

chum (Oncorhynchus keta)

abundance 504-

eggs 496, 497, 49S, 499, 500, 501,

larvae 496. 497. 498, 499, 500, 501,

mortality 504,

spawners. - . 503-504, 50S,

coho (Oncorhynchus kisutch I

pink (Oncorhynchus gorbuscha)

abundance 504-

eggs 496.497.498,499,500,501,

larvae 496. 497, 498, 499, 500, 501,

mortality 504,

-pawners 503-504. 508,

sockeye (Oncorhiinchns iicrku)

348-368,

age groups in run 468-469, 473-

age groups on spawning grounds

delays at Rock Island Dam 35S,

loss below Rock Island Dam

mortalities 345-346,

age

sex

size

segregation of spawning populations

465

tagging

Sanddab:

longfin (Citharichthys xanthostigma) ...

Pacific (Citharichthys sordidus)

-pickled (Citharichthys stigmaeus)

Sandperch (See Mojarra)

Sarda lineolata

676, 67S
636, 680

340,
365, 495
351-353
351-353
495-523
505, 520
503, 504
503, 504
506-519
513-517
495
495-523
•505, 520
503, 504
503, 504
506-519
513-517
339-346,
461-478
-474, 477
468-469,
474-477
360-361
345
348-358
464-465
464-465
464-465
461-463,
468 17s
340-345

Sardine:

Pacific (Sardinops caerulea) 635

scaled (Han ngula pensacolae)

Sardinops caerulea 635

Sauries (Scomberesocidae)

Saury, Pacific (Cololabis saira)

Scabbardfish (Lepidopus xanlusi) 673

Scads i. S'cc .lacks, scad-, and pompanos)

Scallop, sea (Placopecten magellanicus) .... 299 311

annual rings 299 3 I I

calcareous plates . . 301, 302. 304. 305

677, 67s

676, 67s

677, 67s

673. 680

, 636, 680

377
636, 680

COS. oso
60s, 07s
675, 6,79

Page

circuli 299,300,301

clues to aging 299-303, 30S-310

growth marks 299-303, 310

resilium and resilifer. 299, 301, 302, 303, 304, 305, 310

shell as indicator of growth 299-311

shock rings 299, 301, 304

tagging techniques 304, 305, 309

temperature, influence on growth 300

Schroederichthys:

maculatus new species 605-606, 620, 021

n, u genus 604-605, 620, 621

tenuis new species 006-607, 620, 621

Sciaenidae 674, 680

Sciaenops ocellata 370, 371. 372. 373, 374, 375, 376

Scomberesocidae 668, 680

Scomber japonicus 673

Scomberomorus maculatus 370, 371, 372, 373, 374, 375

Scombridae 673. 680

Scopelarchidae 665, 667, 680

Scopelarchus:

guentheri 666, 667, 680

nicholsi 666, 667. 680

spp 666, 667. Oso

Scopelengys tristis 655, Oso

Scopeloberyx robustus 669, 670, Oso

Scopelogadus mizolepis 668, 669, 670, 6S0

Scorpaenidae 674, 676, 680

Scorpionlishes and rockfishes (Scorpaenidae) 674,

676, 680

Seyliorhinidae 581-624

Scyliorhinus:

boa 5.82, 601-602, 619, 620

caniculus. 583, 584, 590, 598, 619

i up, nsis

584

herperius new species 603-604, 619. 620

meadi new species 600-601, 619, 620

r< lifer. . . . 582, 5s7, 602-603, 619. 621 1

spp 597-604.019. 620

stellaris 584,590,619

torazame 599

torrei 598-600, 619, 620

Scyllia 582

Scyllium canescens 583, 593

Searsidae 635. 637 638, 680

,s', bastodi s;

diploproa 676. Oso

Sebastodes:

goodei 676. 680

jordani 676. 680

proriger ■ 676, 680

saxieola 676, 680

spp 076. 6S0

Sebastolobus:

alascuu us 674, 075, 680

altivelis 674, 675, 070. oso

Sediment tracer 427 136

Si ' iphus politus 674, oso

Serranidae 671. oso

Serrivomeridae • 667. oso

St rrirunier sector 667, 680

692

Page

Sexual dimorphism 653

Shad, gizzard (Dorosomu ceprditiniim) 391-425,

490, 491, 492, 493, 494

age composition 398

seasonal changes 398, 411-418

calculated growth 405-406

digestive tract 418-420

food and feeding habits 420-422

lengths and weights of age groups 403-405

life history 391

development and maturation of the egg. 409-41 1

fecundity 412-413

hatching and early development. 417-418

reproduction and early development. . 407-418

reproduction and spawning 413-417

length-weight relation 400-403

ovaries 401-402

seasonal and annual differences in weight . 402-403
scales

annulus 395-397

body-scale relation 398

described 395

survival rate 399-400

yellowfin (See Menhaden, yellowfin)
Shark:

blue (Prionace glauca) 635, 636, 680

bull (Carcharhinus leucas) 593

cal :

brown. (Apristurus brunneus) 581, 589, 592

false (Pseudotriakis mierodon) 583

filetail (Parmaturus xaniurus) 607

dogfish:

Cuban (Squalus cubensis) 590

smooth (Mustelus canis) 529

description 529

food habits 529

range 529

size 529

spiny (Squalus acanthias) 527-554

age determination 536-538

birth process 543-544

birth season 544

color - 528

description 528

distribution 529-530

fecundity 541-543

fishery for 545

food habits 534-536

growth 536-538

length-weight 528, 538

management of 549

mating 541

migrations 530

mortality 544

mortality rate 550

population dynamics. ... . 539-545

populations 538

predators 544

reproduction 539-544

salinity, and 532

Page

serology 534

size at sexual maturity 540-541

spines 529, 536

tagging 532-534

utilization of 545 549

venom gland . 528 529

vitamin A 547

water temperature, and 531

swell (Cephaloscyllium uter) 581, 591

Sharks 527 554, 5S1-624, 635, 678

Sharks:

cat (Scyliorhinidae) 581-624

Ampullae of Lorenzini 589

claspers and clasper siphons 5S7-589, 597

color and color pattern 585-586

denticles, dermal 590-591

denticle crests. 590

growth.. 590

distribution and segregation 583-584

egg cases 582, 586-587

labial fold 597

liver shapes 589

morphometries 596-597,618-622

nasoral grooves 582

nictitating membrane 599

reproduction 582-583, 586-587

rostral cartilages 582

shape of body and fins 589, 591

teeth 591-595, 597

sexual dimorphism 591-593,597

tooth formulas 593

vertebrae :

diplospondylous 595

monospondylous 596

vertebral numbers 595-596

nurse (Orcctolobidae) 582

requiem (Carcharhinidae) 635, 678

Sharks, rays, skates, and chimaeras (Elasmo-

branchii) 635, 679

Sheepshead (Archosargus probatocephalus) 370-373

Shiner:

emerald (Notropis alherinoides) . 490, 491, 492. 49:'.. 494
spottail (Notropis hudsonius) . . 490, 491, 492, 493, 494

Shrimp, brown (Penaeus aztecus) 314, 326, 374, 438

Shrimp, penaeid:

Gulf of Mexico (northwestern) .... ... 437-447

generic key to ■ 438-444

larvae 439-443

myses.... 441,443

nauplii ■ 439-440

postlarvae 441, 443

protozoeae 440, 442

Shrimp, pink (Penaeus duorarum) 313-

338, 374, 438, 449-459

age (size) at recruitment 326, 331-334

distribution :

areal ir':l :,,:'

time ^51 455

693

Pago
estimating growth parameters — fitting curves. 323-

326

estuary, related to 449-454

growth 321-326

Gulf of Mexico 313-338

management 313-338

marking:

Sanibel area 321

Tortugas area 314-321

maximum age 326

migrations 451-457

mortality 326-331

population dynamics 313-338

range:

Sanibel stocks 457

Tortugas stocks 455-457

sex ratio 324

total length — carapace length relation 322-323

weight-length relation 323

yield :

value 334-336

yield:

weight 331-334

Shrimp, rock:

Sicyonia brevirostris 438

Sicyonia dorsalis 438

Sicyonia laevigata 374

Sicyon ia typica 374

Shrimp, seabob {Xiphopeneus krfyeri) 438

Shrimp, white (Penaeus setiferus) 433-434

Sicyonia:

brevirostris 438

dorsalis 438

laevigata 374

typica 374

Silverside, tidewater (Menidia beryllina) 378

Smelt, American (Osmerus mordax) 190

Smelts, deepsea (Bathylagidae) 638-640, 678

Smoothtongue, California (Leuroglossus stilbius) . . . 638,

639, 679
Sole:

Dover (Mieroslomus pacificus) 672,

pet rale (Eopselta jordani) 672.

rex (Glyptoce phulu. s zachirus)

Spawning bed, salmon

dissolved oxygen

intragravel water

metabolic wastes

permeability of bottom materials

677, 679

672, 677, 679

. . 496-501

497

496

499

500
salinity.. 199-500

stability 501

water temperature 496-497

Spawning pelagic fishes 635, 671

Spin/nil mi argentea 674, 680

Sphyraenidae 674, 680

Spot ( l.i iostomus xanihurus) 370, 371, 372

Springer, Stewart 581-624

Squalus:

a, iinthias 527, 554

blainvillei 590

Page

cube7isis 590

Squaretail, smalleye {Tetragonurus cuvieri) . . 673, 675, 680

Stellifer lanceolatus 433

Stenobrachius leucopsarus 659-660, 661, 680

Sternoptychidae 640-643, 680

Sternoplyx diaphana 639, 643, 6S0

Stingray, bat (Holorhinus californicus) 635, 636, 679

Stizostedion vitreum 489-494

Stomias:

alriventer 648, 649, 650

spp 649, 650

St omiatidae .• . . . 648. 650, 680

Straty, Richard R 461-47N

Stromateidae 673, 680

Sudis alrox 664, 665

Sunfish, ocean (Mola mola) 677, 679

Swallower, black (Chiasmodon niger) 674, 678

Sykes, James E 369-379

Symbolophorus californiense 656-657, 680

Symphurus atricauda 677, 680

Synentognathi 668, 6S0

Syngnathidae . . . 668, 680

Syngnathus arcta 668, 680

Syringodium filiforme 377

Taaningichthys:

bathyphilus 658, 659, 680

minimus 658, 659, 680

spp 658, 659, 680

Tactostoma macropus 650, 651, 680

Tagging, salmon:

above and below Rock Island Dam 340-366

below Bonneville Dam 366-368

Talismania bif areata 635, 636, 680

Tampa Bay fishes 369-379

Tampa Bay, West Florida Coast, and Gulf of

Mexico fisheries 370-371

Tetragonurus cuvieri 673, 675, 680

Thalassia lestudinum 377

Toadfish, oyster (Opsanus lav) 428-430

Toadfishes (Batrachoididae) 676, 678

Tonguefish, California {Symphurus atricauda) . . . 677. 680

Tonguefishes (Cynoglossidae) 677, 679

Torpedinidae 635, 680

Torpedo calif or n ica 635, 636, 6S0

Trachinotus:

carolinus 370, 371, 372, 373, 374, 375

falcatus 370, 371, 372, 37:;, 37 1. 375, 376

Trachurus symmetricus 671, 675

Trachypeneus:

constrictus 374

similis 374,438

Trawl:

Cobb Mark-II pelagic 625, 626, 629

collapsible midwater beam 625, 629, 631

Isaacs-Kidd midwater 625, 626, 63 1

midwater 625 63 I

pelagic 625-634

Trawlers, shrimp 314-320

IV. 1 1

Page

Trichiuridae 673, 680

Trout-perch (Percopsis omiscomaycus) 490

Trout:
sea:

spotted (Cynoscion nebulosits) 370, 372

white (Cynoscion arenarius) 370, 372

Tuna, skipjack (Katsuwonus pelamis) 470 4SS

fecundity 484

gonad index 484-485

sexual development and schooling 485-486

spawning 479-488

frequency 483-484

season 482-483

size 481-482

Twelvemile Creek 501

Valenciennellus tripunctulatus 647-648, 649

Venom gland, spinydogfish 528-529

Vessels :

Albatross III 539

Black Douglas 626

Cap'n Bill II 581

Combat 581

Delaware 531, 542

George M. Bowers 317

Horizon 626

John N. Cobb 581, 626

N. B. Scofiehl 581

Oregon 581

Silver Bay 581

Vinciguerria:

lucelia 648, 649, 680

nimbaria 648, 649, 680

poweriae 648, 649, 680

spp 648,680

Vitamin A from dogfish livers 547

W
Wahle, Roy J 339-368

Page
Walleyes (Stizosledion vilreum):

Lake Erie, food of young-of-the-year 489- 494

algae 492

cladocerans 492

copepods 492

fish 490, 491, 492. 493

insects 491, 492, 493

Whitefish (Corcgonus clupeaformis) 489

Whitefish, pygmy (Prosopium coulter/) 555-579

abundance and distribution 556, 558

age and growth 564

associated fishes 563-564

body-scale relation 564-565

dwarfed form 576

ecological distribution 560-563

food habits 566-571

dielvariations in diet 570-571

feeding behavior 569

growth and diet 571-572

interlake movement 563, 576

interspecific competition 575-576

Naknek River distribution 558

maturity 572

reproduction 572-575

fecundity 573

sex ratios 572

spawning 573-575

schooling behavior 562

species plasticity 572, 576, 577

trawls, tow nets, seines, gill nets 557-558

underwater observations 562, 569, 574

Wolf ert, David R 489-494

X YZ

Xiphopi neus kroycri 438

Yoshida, Howard 0 479-488

Zaniolepidae 676, 680

Zaniolepis frenata 676, 680

Zoarchidae 676, 680

<;<)-

FISHERY
BULLETIN

Volume 65

No. 1

UNITED STATES
DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service
Bureau of Commercial Fisheries

PUBLICATION BOARD

Robert L. Hacker Carl E. Abegglen

Philip R. Nelson Sidney Shapiro

Edward A. Power Frank T. Piskur

Mitchell G. Hanavan Walter H. Stolting

MB'. WHOI MBKAm

WH 11VR V

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