NOAA TR NMFS SSRF-656

A UNITED STATES
DEPARTMENT OF
COMMERCE
PUBLICATION

NOAA Technical Report NMFS SSRF-656

/ V \

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Marine Fisheries Service

The Calico Scallop,

Argopecten gibbus

DONALD M. ALLEN and T. J. COSTELLO

lianne Biotogical Lalwuluii
LlBRARy
SEP13W2
Vitoods Hole, Mass.

SEATTLE, WA
May 1972

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^O ATMOSp^^

''Went of

U.S. DEPARTMENT OF COMMERCE
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NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
Robert M. White, Administrator

NATIONAL MARINE FISHERIES SERVICE
Philip M. Roedel, Director

NOAA Technical Report NMFS SSRF-656
The Calico Scallop,

Argopecten gibbus

DONALD M. ALLEN and T. J. COSTELLO

Marine Biologic2l Lbor :tory

LIBRARY

SEP 1 3 1972

Woods Hole, Mass.

SEAHLE, WA
May 1972

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CONTENTS

Page

Introduction 1

Biology

Classification 1

Description 2

Distribution 2

Environment 4

Relative abundance 5

Reproduction 5

Age and growth 8

Mortality 9

Associated organisms 10

Behavior 10

Fishery

General 12

North Carolina 15

Florida east coast 15

Northeastern Gulf of Mexico 16

Summary 16

Literature cited 17

Figures

No. Page

1. Calico scallop, showing left valve (top) and right valve (bottom) 2

2. General distribution of the calico scallop is shown by the stippled area 3

3. Relative abundance of the calico scallop, Cape Kennedy grounds, 1960-1966. One

fathom equals 1.8 m 6

4. Spawn, ejected by the calico scallop on the left, appears as a milky cloud 7

5. A spat trap is a nylon mesh bag (top) containing unlaid polyethylene line (bottom

right). Young scallops enter the bag as larvae, grow, and are permanently
trapped when their size (center) exceeds that of the mesh opening. Spat traps
are used to monitor spawning success by season and area 8

6. Animals associated with calico scallops on the Cape Kennedy grounds, Florida, include

shrimp, crabs, gastropod and bivalve mollusks, starfish, brittle stars, sea urchins,

sand dollars, and fish H

7. Juvenile calico scallops swimming in aquarium 12

8. Locations of calico scallop fishing grounds (wavy lines) and cities referred to in text

(numerals) 13

9. A factory-type scalloper, with sorting and shucking machinery mounted on deck 14

Table

No.
1. Annual production and value of calico scallops, southeastern United States 1959-1970 . 13

iii

The Calico Scallop, Argopecfen gibbus

By

DONALD M. ALLEN and T. J. COSTELLO, Fishery Biologists

National Marine Fisheries Service

Southeast Fisheries Center

Miami Laboratory

Miami, Florida 33149

ABSTRACT

The calico scallop, Argopecten gibbus, supports a developing fishery off the southeastern
coast of the United States and in the Gulf of Mexico. Information is given on classification,
description, distribution, environment, relative abundance, reproduction, age and growth,
mortality, associated organisms, behavior, and the fishery.

INTRODUCTION

The calico scallop, Argopecten gibbus, a com-
mercially valuable shellfish, is fished in the At-
lantic Ocean off North Carolina and Florida and
in the northeastern Gulf of Mexico. Develop-
ment of the fishery has been slow^ and erratic,
due to problems related to stock availability and
processing. The apparent large concentrations
of scallops off the Florida east coast and the in-
troduction of scallop shucking and eviscerating
machines suggest, however, that the harvest of
calico scallops will increase in the next few years.

Biologists at the National Marine Fisheries
Service, Southeast Fisheries Center, Miami Lab-
oratory, Miami, Fla., are studying the biology of
the calico scallop to determine which ecological
factors control distribution and abundance and
to predict seasonal and annual availability of
the harvestable stock. As a first step, this re-
port summarizes available information concern-
ing the biology and the fishery of the calico
scallop.

BIOLOGY

Classification

' Contribution No. 207, National Marine Fisheries
Service, Southeast Fisheries Center, Miami Laboratory,
Miami, Fla.

The calico scallop, Argopecten gibbtis (Linne) ,
is a benthic marine pelecypod mollusk of the
family Pectinidae. Formerly known as Pecten
gibbiis or Aqidpecten gibbtcs, the species was
placed in the genus Argopecten by Waller
(1969). In the same genus he also placed two
closely related species that occur within the
range of the calico scallop. These are the nucleus
scallop, Argopecten nucleiis (Born) , and the bay
scallop, Argopecten irradians (Lamarck) , which,
unlike the calico scallop, are generally restricted
to very shallow water in the region of overlap-
ping distribution. Methods of separating these
scallops by shell characteristics were given by
Waller. A calico scallop is shown in Fig-
ure 1.

The shell morphology of the calico scallop var-
ies with locality (Bullis and Ingle, 1959) and
perhaps environment (Waller, 1969). The sub-
specific status of a less convex form, A. gibbtis
portusregii, from buoys off South Carolina was
questioned by Waller.

Figure 1. — Calico scallop, showing left valve (top) and
right valve (bottom).

Description

A thorough description of the calico scallop
shell was given by Waller (1969). He noted
that this species generally reaches 40 to 60 mm
in shell height (a straight line measurement of
the greatest distance between the umbo and the
ventral margin). Maximum size reported is
about 80 mm in shell diameter (a straight line
measurement of the greatest distance between

the anterior margin and the posterior margin)
(Roe, Cummins, and Bullis, 1971). Shell di-
ameter is about the same as shell height in in-
dividual small scallops. As height increases,
however, diameter increases more rapidly." The
height-diameter relationship for calico scallops
ranging from 43 to 61 mm in height was shown
by Wells, Wells, and Gray (1964).

Both valves are well inflated and according to
Waller (1969) "generally equiconvex to slightly
left-convex." The disk outline is "roughly equi-
lateral to slightly produced posteriorly." There
are 17 to 23 ribs on the right valve. Waller noted
that the color of the left (upper) valve is var-
iable, usually with red or maroon mottling or
banding on a white or yellow background. The
right (lower) valve is more lightly pigmented
with the same colors as the left valve.

Distribution

The calico scallop apparently is restricted to
the western North Atlantic Ocean. Distribution
of this species is shown in Figure 2. Its known
range extends from the northern side of the
Greater Antilles and throughout the Gulf of
Mexico to Bermuda and slightly north of Cape
Hatteras (Waller, 1969; Kirby-Smith^ Mer-
rill'). According to Waller, however, the "pre-
cise southern limit" of the calico scallop is ob-
scured by confusion with other species. Calico
scallop shells, but no living animals, were found
off Delaware Bay (Merrill, see footnote 4). Al-
though this species might be expected from the
Bahama Islands, its occurrence there has not
been verified.

This scallop, generally found on continental
or insular shelves, was reported from depths less
than 2 m (Kirby-Smith, see footnote 3) to 370 m
(Waller, 1969). The depths of occurrence vary
with locality. Near the southern end of its range,
on the northern side of the Greater Antilles, this
species was caught in depths of 22 to 26 m

- Unpublished data on file at the National Marine
Fisheries Service, Southeast Fisheries Center, Miami
Laboratory, Miami, Fla. 33149.

^ William W. Kirby-Smith, Duke University Marine
Laboratory, Beaufort, N.C. Personal communication,
1971.

* Arthur S. Merrill, Laboratory Director, National
Marine Fisheries Service, Northeast Fisheries Center,
Oxford Laboratory, Oxford, Md. Personal communica-
tion, 1971.

N,
40

30-

20-

10-

ELAWARE BAY

,;CAPE HATTERAS
>^pkPB LOOKOUT

BERMUDA

NORTH ATLANTIC
OCEAN

■^^'•^^ Dominican I™

REPUBLIC

RICO

CARIBBEAN SEA

\»

If

T

100

15

— I r; 'T — r; "t

90 80

Figure 2. — General distribution of the calico scallop is shown by the stippled area.

60W

(Waller)" and 277 m (Waller, 1969). In the
southeastern Gulf of Mexico, off the Yucatan
Peninsula, it was reported from 37 m (Springer
and Bullis, 1956) to 78 m (Rice and Kornicker,
1965) . In the northern Gulf, this species is com-
mon in depths of 32 to 65 m (Parker, 1960);
and in the northeastern Gulf, it was reported
from 11 to 93 m (Carpenter, 1967) . In the east-
ern Gulf, calico scallops were found in depths
from 6 m (Bullis and Thompson, 1965) to 46 m
(Bullis and Ingle, 1959). Off the Florida east
coast, the calico scallop was reported from 9 to
74 m by Drummond (1969) , although maximum

^ Thomas R. Waller, Associate Curator, Division of
Invertebrate Paleontology, Smithsonian Institution,
Washington, D.C. Personal communication, 1970.

depth of occurrence in this area may be greater
(Cummins) ." Off North Carolina, south of Cape
Hatteras, calico scallops were found from about
13 m (Bullis and Thompson, 1965) to at least
94 m (Cummins, Rivers, and Struhsaker, 1962).
At the northern end of its range, north of Cape
Hatteras, reported depths of occurrence range
from 33 to 44 m (Merrill, see footnote 4). At
Bermuda, the calico scallop occurs in less than
2 m of water (Kirby-Smith, see footnote 3) .

The calico scallop inhabits open marine water
and does not usually occur in estuarine areas as
do the nucleus scallop and the Atlantic bay

° Robert Cummins, Jr., Chief, National Marine Fish-
eries Service, Southeast Fisheries Center, Brunswick
Laboratory, Brunswick, Ga. Personal communication,
1971.

scallop (Waller, 1969). At Bermuda, however,
calico scallops were found in an almost complete-
ly enclosed sound (Neumann, 1965; Kirby-Smith,
see footnote 3).

Environment

Factors that probably influence distribution
and/or growth of the calico scallop include cur-
rents, temperatui-es, salinities, substrates, and
food supply.

Currents may be of primary importance in
controlling distribution of scallop larvae and, ul-
timately, the positioning of the scallop beds.
Kirby-Smith (1970) suggested that North Car-
olina populations of scallops may be at least par-
tially maintained by larvae transported from
Florida scallop grounds via the Gulf Stream.
The greatest concentrations of calico scallops are
found near coastal prominences such as Cape
San Bias and Cape Kennedy, Fla.; and Cape
Lookout, N.C. Bullis and Cummins (1961) sug-
gested that the Cape Kennedy projection causes
"interruption and eddying" that produces "re-
petitive settling of scallop larvae . . . creating
a permanent resource." The scallop beds are
generally distributed along the flow lines of cur-
rents (National Marine Fisheries Service)' and
are thus oriented parallel to the coastline. On
the Cape Kennedy grounds, scallops are irreg-
ularly distributed but "occur in long narrow
bands" (Bullis and Cummins, 1961). Some
bands or beds are more than 800 m long and
several hundred meters wide (Roe, Cummins
and Bullis, 1971). An elliptical-shaped bed
16 km long near Cape Lookout was reported by
Cummins, Rivers, and Struhsaker (1962). A
bed 16 km long and 8 to 16 km wide near Cape
San Bias was reported by Bullis and Ingle
(1959).

The importance of temperature in controlling
reproduction and survival, and thus geographic
distribution, of marine bivalves, including the
calico scallop, was emphasized by Pulley (1952).
Waller (1969) suggested that calico scallop dis-

tribution is limited primarily by temperature.
According to Parker (1956), the calico scallop
is one of a faunal assemblage in the northern
Gulf of Mexico that inhabits waters deep enough
to avoid winter cooling. Bottom temperatures
associated with calico scallops range from 9.9°C
(Merrill see footnote 4) to 33.0°C (Waller,
1969). Vernberg and Vernberg (1970) ob-
served, however, that calico scallops collected
near the northern end of their range, off North
Carolina, did not survive 48-hr exposure to lab-
oratory water temperatures of 10°C, and have
"tropical affinities." Near Cape Lookout, a cal-
ico scallop bed was "usually dominated by Car-
olinian coastal waters" (Wells, Wells, and Gray,
1964), although bottom temperatures in this
area show considerable fluctuation in conjunction
with winter and spring meanders of the Gulf
Stream (Grassle, 1967). North of Cape Hat-
teras, the existence of calico scallops may coin-
cide with a mass of relatively warm water (Mer-
rill, see footnote 4).

Salinities from areas where calico scallops
occur are fairly stable and range from about 31
to 37;:*', (Anderson, Moore, and Gordy, 1961;
Hulings, 1961; Grassle, 1967; Pequegnat and
Pequegnat, 1968).

The substrates required or preferred by the
calico scallop may vary with scallop size. Young
scallops up to about 25 mm in height are found
byssally attached to whole or broken mollusk
shells. Although commonly attached to dead
scallop shells (Commei'cial Fisheries Review,
1962) , they are also found on dead shells of other
mollusks (Allen)' and on live scallop shells
(Wells, Wells, and Gray, 1964). Shells may be
necessary for successful settlement of small scal-
lops (Kirby-Smith, 1970) , but spat may com-
pete with adults for optimum substrate (Roe,
Cummins, and Bullis, 1971).

Larger scallops, usually unattached, are re-
ported from bottoms composed of hard sand
(Rivers, 1962a), sand and shell (Sastry, 1962;
Cummins, Rivers and Struhsaker, 1962), quartz
sand (Hulings, 1961), smooth sand-shell-gravel
(Struhsaker, 1969a), fairly clean, medium-

' National Marine Fisheries Service (in cooperation
with state, industry, and university groups in Florida,
Georgia, South Carolina, and North Carolina). 1971.
Joint plan for the calico scallop fishery. Unpublished
report, 115 p., filed at the National Marine Fisheries
Service, Southeast Fisheries Center, Miami Laboratory,
Miami, Fla. 33149.

' Allen, D. M. 1971. Ecology of the calico scallop,
Argopecten gibbus, as determined by spat monitoring.
Unpublished manuscript filed at the National Marine
Fisheries Service, Southeast Fisheries Center, Miami
Laboratory, Miami, Fla. 33149.

grained quartz sand (Hulings and Hemlay,
1963), and sand and dead shell (Drummond,
1969). Grassle (1967) found calico scallops as-
sociated with a mud sediment that contained a
high percentage of quartz and shell.

Essentially nothing is known concerning the
food requirements of the calico scallop. This
subject was discussed by Kirby-Smith (1970),
who suggested that zooplankton may be an im-
portant source of nutrition. Where scallop
abundance is greatest, plankton concentration
may be high, since upwelling in the general areas
of Cape San Bias, Cape Kennedy, and Cape Look-
out is reported respectively by Gaul, Boykin, and
Letzring (1966), Taylor and Stewart (1959),
and Wells and Gray (1960).

On the Cape Kennedy grounds, the locations
of individual scallop beds vary from year to year
and probably are determined by environmental
conditions which control setting and survival of
larval scallops (National Marine Fisheries Ser-
vice, see footnote 7). Personnel of the Miami
Laboratory are attempting to relate scallop
abundance and growth to substrate types, and
to water temperatures and currents now being
monitored on the Cape Kennedy grounds.

Relative Abundance

The relative abundance of calico scallops var-
ies between areas. The greatest known abun-
dance is located off the Florida east coast near
Cape Kennedy, with lesser concentrations near
Cape Lookout, N.C., and in the northeastern
Gulf of Mexico near Cape San Bias, Fla. Con-
centrations were also reported from the eastern
Gulf of Mexico between Sanibel Island and Dry
Tortugas (Bullis and Ingle, 1959; Carpenter,
1967). Generally fewer scallops are found else-
where within the calico scallop range.

Abundance also varies within areas. Young
calico scallops in the northeastern Gulf of Mex-
ico were more abundant on fouling arrays an-
chored 18 km offshore in 31 m than on those an-
chored 3 km offshore in 19 m and 40 km offshore
in 46 m (Pequegnat and Pequegnat, 1968) . Vari-
ations in average abundance of commercial size
scallops off the Florida east coast for 1960 to 1966
were given by Drummond (1969) as follows:
Scallops were most abundant on the southern
portion of the grounds in 28 to 65 m (Fig. 3).
At these depths, the average rate of catch with

a 2.4-m (8-ft) scallop dredge ranged from 3.9
to 12.8 bu per hour. For these catches, 1 bu
equaled 36 kg (80 lb.) of scallops in the shell.
The rate of catch was highly variable; within
one area, catches ranged from 0 to 54 bu per
hour. Within a scallop bed, also located off the
Florida east coast, average scallop densities were
about 43 individuals per square meter (4 per
square foot) (Cummins, 1971), but densities
may exceed 108 per square meter (10 per square
foot) (Roe, Cummins, and Bullis, 1971).

Abundance varies with scallop size, although
this is poorly documented. Dense concentrations
of scallop spat are caught in spat traps, e.g., 107
individuals per liter (3,000 per cubic foot) per
2-month period (Allen, see footnote 8). While
density of spat set naturally on the bottom is
probably much less, catches of small scallops with
dredges at times exceed catches of large indi-
viduals (Commercial Fisheries Review, 1968).

Abundance varies both seasonally and annu-
ally. Monthly changes in scallop abundance by
area off the Florida east coast were shown by
Drummond (1969). On these grounds, abun-
dance (as measured by catch rate) was highest
from September to December in 1967 and 1968
(Roe, Cummins, and Bullis, 1971). Abrupt
yearly differences in scallop abundance have been
reported for the grounds off North Carolina
(Cummins, 1971; Lyles, 1969) and in the north-
eastern Gulf of Mexico (Bullis and Ingle, 1959;
Hulings, 1961).

Reproduction

The calico scallop is hermaphroditic. When
this species spawned in the laboratory, the sperm
and eggs (in that order) were ejected sepa-
rately into the water where fertilization took
place (Costello et al.).°

We observed, based on gonadal color (see be-
low) , that some calico scallops as small as 19 mm
in height are ripe, which indicates either ripeness
at a very early age or that these small scallops
are older than suspected (see footnote 2). Roe,
Cummins, and Bullis (1971) stated that spawn-
ing of the calico scallop "is related to age rather

" Costello, T. J., J. H. Hudson, J. L. Dupuy, and S.
Rivkin. 1971. Larval development of the calico scallop,
Argopecten gibbus. Unpublished manuscript filed at the
National Marine Fisheries Service, Southeast Fisheries
Center, Miami Laboratory, Miami, Fla. 33149.

Figure 3. — Relative abundance of the calico
scallop, Cape Kennedy grounds, 1960-1966.
One fathom equals 1.8 m. (Modified from
Drummond, 1969.)

than size," and suggested that spawning can be-
gin at a young age.

Spawning in the calico scallop, similar to that
in certain other bivalves, is perhaps controlled
primarily by water temperatures and may be
initiated by rising temperatures (Roe, Cum-
mins, and Bullis, 1971) . The gonads of scallops
caught on the Cape Kennedy grounds in October
1969 and maintained in the laboratory at about
25 °C changed color from light pink to orange-
red within 2 weeks. These scallops were then
induced to spawn (Fig. 4) by rapidly raising

the ambient water temperature to 30°C (Miller
and Drummond).'" Conversely, low tempera-
tures may terminate spawning (Roe, Cummins,
and Bullis, 1971).

Several methods have been used to determine
the seasonal pattern of spawning of the calico

'" Miller, G. C, and B. R. Drummond. 1969. Report
on gonadal color change and spawning of calico scallops
at TABL, October 23-November 13, 1969. Unpublished
report, 5 p., filed at the National Marine Fisheries Ser-
vice, Southeast Fisheries Center, Miami Laboratory,
Miami, Fla. 33149.

Figure 4. — Spawn, ejected by the calico scallop on the left, appears as a milky cloud.
(Photo by George C. Miller, National Marine Fisheries Service.)

scallop. The color of calico scallop ovaries var-
ies with the degree of ripeness and is useful to
determine maturation and spawning time.
Resting ovaries are whitish-yellow, maturing
ovaries are yellow-orange, and ripe ovaries are
bright reddish-orange, according to Roe, Cum-
mins, and Bullis (1971). The seasonal distri-
bution of scallops of known age may also provide
some insight concerning spawning time. Preli-
minary growth data for young scallops (see sec-
tion on Age and Gro\vth) suggest that scallops
2 months old are about 17 mm in shell height.
Consequently, occurrence of scallops of this size
or smaller may indicate recent spawning. In ad-
dition, spawning time may be determined by ex-
posure of spat collecting traps for known time
periods throughout the year (Fig. 5).

Techniques dependent upon the minimum sizes
of scallops and on the catches of spat traps may

not be valid for determining spawning time for
a particular area if scallop larvae ai'e transported
into the area from great distances as suggested
by Kirby-Smith (1970).

Off the Florida east coast, maturation, based
on ovarian color, begins in late summer and cul-
minates in the spring, with spawning extending
from late February to June (Roe, Cummins, and
Bullis, 1971). These authors concluded, how-
ever, that protracted spawning occurs in some
areas because small scallops were found through-
out most of the year. Our observations on ovar-
ian color, minimum sizes, and spat trap collec-
tions also indicate that some spawning occurs
year around (see footnote 2).

Off North Carolina, observations on scallop
gonads indicated that spawning took place from
May to June (Kirby-Smith, 1970). Small scal-
lops 10 mm or less in height, however, were

Figure 5. — A spat trap is a nylon mesh bag (top) containing unlaid polyethylene line (bottom right).
Young scallops enter the bag as larvae, grow, and are permanently trapped when their size (center)
exceeds that of the mesh opening. Spat traps are used to monitor spawning success by season and area.

observed in April (Wells, Wells, and Gray,
1964); in May (Commercial Fisheries Review,
1962); and in May, June, and October (Kirby-
Smith, 1970). According to Kirby-Smith
(1970), the fall occurrence of small scallops in
the absence of local spawning may indicate larv-
al transport into North Carolina waters.

In the northeastern Gulf of Mexico, gonads
of calico scallops were highly developed in the
spring, and spawning was presumably finished
by late summer, according to Bullis and Ingle
(1959). Small calico scallops," however, were
found attached to fouling arrays from September
to July (Pequegnat and Pequegnat, 1968).

'"■ Specimens reported as Aquipecten gibbiis nucleus
by Pequegnat and Pequegnat (1968) were later identi-
fied as Argopecten gibbiis (Waller, see footnote 5).

In the eastern Gulf of Mexico, calico scallops
about 12 mm in shell height were abundant in
late July (Joyce)," indicating that spawning
occurred at least in the late spring or early
summer.

Age and Growth

Rate of growth of the calico scallop probably
varies with size, season, and environment.

Larval development was described from lab-
oratory studies (Costello et al, see footnote 9).
These authors reported that the length of plank-
tonic larval life from fertilization to settlement

'° Edwin A. Joyce, Jr., Supervisor, Marine Research
Laboratory, Florida Department of Natural Resources,
St. Petersburg, Fla. 33731. Personal communication,
1971.

is about 14 days and that the spat are about
0.25 mm in shell height when first set.

A few observations have been made on the
shell growth of young calico scallops following
setting. Calico scallops (apparently small spe-
cimens) collected from fouling arrays in the
northeastern Gulf of Mexico grew at a minimum
rate of 3.1 mm (presumably in shell height) per
week in April (Pequegnat and Pequegnat, 1968) .
Oflf the Florida east coast, young calico scallops
found in spat collecting traps after 10 weeks'
exposure time had a maximum size of 27 mm
in shell height (Allen, see footnote 8).

Shell growth of large scallops was estimated by
Bullis and Ingle (1959) for calico scallops caught
in the northeastern Gulf of Mexico. From re-
portedly "inadequate" size frequency data, they
tentatively estimated that scallops averaging
54 mm (probably in shell diameter) were 24
months old.

Growth of calico scallops from the North Car-
olina grounds was estimated using several tech-
niques and reported as increases in shell depth by
Kirby-Smith (1970). In this case, shell depth
refers to shell height (Kirby-Smith, see footnote
3) . For scallops ranging from about 19 to 28 mm
in height, maximum growth (converted from the
daily rate) was 2.2 mm per month. Calico scal-
lops from North Carolina that ranged from 43
to 61 mm in shell height were estimated to be
2 years old (Wells, Wells, and Gray, 1964).

Roe, Cummins, and Bullis (1971) estimated
growth rates from size frequencies of calico scal-
lops collected oif the Florida east coast. They
reported that growth (in shell diameter) in-
creases rapidly up to about 50 mm. For scallops
having mean sizes from 13.9 to 37.8 mm, average
growth was 4.0 mm per month. For scallops
having mean sizes from 63.5 to 65.5 mm, average
growth was 0.3 mm per month. These authors
concluded that the calico scallop becomes senile
at a size of 75 to 80 mm, that maximum size is
80 mm, and that maximum age averages 18 to 20
months and does not exceed 24 months.

In a recent innovation, calico scallops were
marked with a quick-setting cement to measure
growth increments over known time periods
(Hudson)." Preliminary studies oh the Cape

Kennedy grounds indicate that marked scallops
reach 40 to 45 mm in shell height in 6 to 8 months
(Miller and Hudson)." Age-growth estimates
shown by Weeks (1970) are in error.

Mortality

The disappearance of calico scallops from an
area is common (Bullis and Ingle, 1959; Hulings,
1961; Commercial Fisheries Review, 1962;
Kirby-Smith, 1970; Roe, Cummins, and Bullis,
1971; Porter and Wolfe, in press ; Joyce, see foot-
note 12) and has often been attributed to mor-
tality or migration, although the ability of calico
scallops to migrate has not been shown. Mortal-
ity or poor recruitment is indicated when only
empty scallop shells are found on formerly pro-
ductive scallop grounds.

Very heavy natural mortality of calico scal-
lops was reported to occur in late winter on the
northern two-thirds of the Cape Kennedy
grounds (Bullis and Cummins, 1961). The
joined valves containing scallop flesh indicated
very recent mortality. At the same time, live
scallops were fairly abundant on the southern
third of the Cape Kennedy grounds. Therefore,
these authors concluded that factors affecting
mortality may be limited to distinct areas.

The causes of mass mortalities of calico scal-
lops are not known. Near Cape Hatteras, N.C.,
where calico scallops occur, drastic fluctuations
of water temperature may cause mortalities of
benthic invertebrates ( Cerame-Vivas and Gray,
1966) . Some mortalities may be a result of pre-
dation. For example, sea stars (Asterias) , which
have been observed feeding on scallops, occur in
vast numbers on the Cape Kennedy grounds
(Roe, Cummins, and Bullis, 1971). Extremely
large scallops which are "often in poor condition"
and may be "at the end of their life span" are
present year around on the Cape Kennedy
grounds; the adductor muscle in these scallops is
small, discolored, and often too weak to close the
shell (Bullis and Cummins, 1961). According
to Carpenter (1967) , calico scallops in the north-
eastern Gulf of Mexico die in the late summer,
"presumably after spawning" and following

'* Hudson, J. H. Marking scallops with quick-setting
cement. Submitted to Proc. Natl. Shellfish Assoc, for
1971, vol. 62, 7 MS p.

" Miller, G. C. and J. H. Hudson. 1971. Growth of
calico scallops, Argopecten gibbus. Unpublished manu-
script filed at the National Marine Fisheries Service,
Southeast Fisheries Center, Miami Laboratory, Miami.
Fla. 33149.

a decrease in the size of the adductor muscle.
There were also indications of a postspawning
die-off on the Cape Kennedy grounds (Roe, Cum-
mins, and Bullis, 1971).

For the Cape Kennedy grounds, average
monthly mortality rates, primarily natural, cal-
culated for the period December to October were
about 20 '^r (Roe, Cummins, and Bullis,
1971).

Associated Organisms

Plants and animals associated with the calico
scallop undoubtedly influence its setting, growth,
and survival.

Calico scallops have been reported to occur in
beds of turtle grass, Thalassia testudinum, in
Bermuda (Kirby-Smith, see footnote 3).

Marine animals associated with the calico
scallop are categorized as follows: epifaunal
and endofaunal community (Wells, Wells, and
Gray, 1964) ; benthic invertebrates (Grassle,
1967); crustaceans (Hulings, 1961); mollusks
(Wells, Wells, and Gray, 1961; Hulings and
Hemlay, 1963; Porter and Wolfe, in press) ; echi-
noderms (Wells, Wells, and Gray, 1961, 1964;
Hulings and Hemlay, 1963; Gray, Downey, and
Cerame-Vivas, 1968) ; and fishes (Moe, 1963;
Anderson and Gehringer, 1965; Struhsaker,
1969a). A few animals associated with calico
scallops on the Cape Kennedy grounds are shown
in Figure 6.

Marine invertebrates that live on and in the
calico scallop "probably reduce growth or repro-
ductive potential . . . rather than cause the scal-
lop's death," according to Wells, Wells, and Gray
(1964). Sindermann (1971) reported, however,
that "barnacles, tube worms, and corals can re-
duce survival of calico scallops." We have noted
that fouling by barnacles may prevent complete
closure of the valves and thus predators can be
admitted more easily (see footnote 2).

Invertebrates reported as parasites (in some
cases, commensals) of the calico scallop are a
nematode Porrocaecum pectinis (Hutton, 1964);
a trematode Procfoeces sp. (Sindermann)"; the

" Carl J. Sindermann, Laboratory Director, National
Marine Fisheries Service, Northeast Fisheries Center,
Sandy Hook Laboratory, Highlands, N.J. 07732. Per-
sonal communication, 1970.

polychaetes Ceratonereis tridentata and Poly-
dora websteri (Wells and Wells, 1962) ; the
decapod crustaceans Pontonia margarita and
Pinnotheres maculatus (Wells, Wells, and Gray,
1964); and the gastropod mollusks Odostomia
seminuda (Wells and Wells, 1961) and Odosto-
mia bisutalaris (Cheng, 1967).

Predators of the calico scallop are poorly
known and observations on food habits of the
many associated species would be useful. Re-
ported as known predators are the starfishes
Astropecten articukttus (Wells, Wells, and Gray,
1961) and Asterias (Roe, Cummins, and Bullis,
1971), and puffers Sphoeroides (Roe, Cummins,
and Bullis, 1971). Scallops held in cages on the
Cape Kennedy grounds were drilled by unidenti-
fied gastropod mollusks (see footnote 2).

Reported as possible predators are the gastro-
pod mollusks Cantharus multangulus and Murex
fulvescens (Wells, Wells, and Gray, 1964); and
the thorny stingray Dasyatis centroura (Struh-
saker, 1969b). In addition, the Florida horse
conch Pleuroploca gigantea and an unidentified
octopus may be predators (see footnote 2).

Behavior

Calico scallop larvae are planktonic and appar-
ently occur at all levels in the water column
since young scallops were found attached to
fouling arrays distributed from surface to bot-
tom in 46 m of water in the northeastern Gulf
of Mexico (Pequegnat and Pequegnat,
1968).

Small calico scallops attach byssally to a va-
riety of surfaces, including mollusk shell, tile,
and various synthetic materials. Although bys-
sal attachment is most pronounced in small scal-
lops (those less than about 25 mm in height),
scallops up to about 54 mm in height attached
to a fiber glass-coated water table (Allen, see
footnote 8) .

Several observations have been made on the
swimming activity of the calico scallop. Accord-
ing to Mellon (1969), the calico scallop "has
heavy valves and swims only rarely." Zahl
(1969) reported, however, that the calico scal-
lop is a "champion" swimmer. From a submer-
sible on the Cape Kennedy grounds, "sporadic"
swimming by some calico scallops was noted al-

io

Figure 6. — Animals associated with calico
scallops on the Cape Kennedy grounds,
Florida, include shrimp, crabs, gastro-
pod and bivalve mollusks, starfish, brit-
tle stars, sea urchins, sand dollars, and
fish. (Photo by George C. Miller, Na-
tional Marine Fisheries Service.)

though most remained inactive." Swimming
ability, however, may be enhanced by the rela-
tively flat, lightweight valves of small scallops
as compared with the convex, heavy valves of
large scallops (Waller, 1969) which are often
heavily fouled (Cummins, see footnote 6). In
the laboratory, small scallops swim more readily
than large scallops (Fig. 7). On the Cape Ken-

nedy grounds, scallops 10 to 20 mm in shell di-
ameter swam "up to the camera" of RUFAS
(Remote Underwater Fisheries Assessment Sys-
tem)'' and scuba divers observed a scallop about
40 mm in shell height swim to 1 m off the bottom
(see footnote 2). From a submersible, lying in
a dense concentration of adult scallops on the
Cape Kennedy grounds, a few individuals were

'" Bureau of Commercial Fisheries (now National
Marine Fisheries Service) , Brunswick, Ga., Quarterly
Report 12/31/69.

" Bureau of Commercial Fisheries (now National
Marine Fisheries Service) , Pascagoula, Miss., RV George
M. Bowers Cruise 93, 6/1-3 and 6/17-25/70, July 10, 1970.

11

Figure 7. — Juvenile calico scallops swimming in aquarium.

obsei-\'ed to swim to about 46 cm off the bottom
and then resettle about 30 cm away (Cummins,
see footnote 6).

Calico scallops are often found in depressions
on the sea bottom, as suggested by Rivers
(1962a). Video tapes of the bottom off Cape
Kennedy produced by RUFAS show that gen-
erally, scallops (size not given) were in furrows
that run in a northwest-southeast direction or
"settled individually in small conical depres-
sions" (Commercial Fisheries Review, 1970).

FISHERY

General

The locations of the calico scallop fishing
grounds off North Carolina and the Florida east
coast and in the northeastern Gulf of Mexico are
shown in Figure 8. Production and value of cal-

ico scallops for these areas are given in Table 1.
Scallops landed in Georgia were caught off the
Florida east coast.

The commercial production of calico scallops
remains relatively low and fluctuates markedly
in all three fishing areas. This condition is ap-
parently caused by yearly variations in location
and productivity of scallop beds compounded by
problems of sorting, shucking, and eviscei'ating
scallops (National Marine Fisheries Service, see
footnote 7). The size and shape of the calico
scallop generally prevent economical shucking
by hand (Commercial Fisheries Review, 1960);
and there is only one locality (near Cape Look-
out, N.C.) where hand-shucking was feasible for
an extended period (Cummins, 1971). This has
led to the development and use of shore-based
processing equipment that automatically shucks
and eviscerates scallops, and to factory-type scal-
lop vessels (Fig. 9) with machinery to sort the

12

20-

10-

LEGEND

©Williston ®St. Marys ©Carrabelle

©Beaufort ®St. Augustine @Apalachlcola

©Salter Path ®Daytona Beach i5>Panama City

©Darien ©Port Canaveral @Gult Shores

©Brunswick @Ft. Pierce ©Mobile

XI

90°

1^

:x

70° W.

Figure 8. — Locations of calico scallop fishing
grounds (wavy lines) , and cities referred
to in text (numerals). (Modified from
Cummins, 1971.)

Table 1. — Annual production and value of calico scallops, southeastern United States 1959-1970.
[In thousands of pounds of meats and thousands of dollars (ex-vessel price).]

Year

North Carolina

Georgia

Florida East Coast

Northeastern'
Gulf of Mexico

Poiinds

Dolla'

1959'

6

3

1960

112

45

1961

22

9

1962

__

1963

— —

1964

- —

1965

871

245

1966

1,857

369

1967

1,389

309

1968'

__

_^

1969

__

_^

1970

1,574

498

Pounds

Dollars

59

2

63

28
1

34

Pounds

21

30

181

196

Dollars

Pounds

Dollars

No data

No data

No data

No data

No data

No data

16

5

8
13

172
196

16

^ In the Gulf of Mexico, calico scallop production began in 1958. Until 1962, however, calico scallops were in-
cluded with and listed as bay scallops in the U.S. Fish and Wildlife Service Statistical Digests (Carpenter, 1967).

= 1959-1967 data from U.S. Fish and Wildlife Service Statistical Digest Nos. 51-61.

' Dash indicates less than 500 pounds or 500 dollars.

* 1968-1970 data rounded off from North Carolina Landings, Georgia Landings, and Florida Landings, published by
Bureau of Commercial Fisheries for 1968 and 1969, and National Marine Fisheries Service for 1970 (in cooperation
with state agencies). Data shown for 1970 are preliminary and subject to change.

13

Figure 9. — A factory-type scalloper, with sorting and shucking machinery mounted on deck.
(Photo by George C. Miller, National Marine Fisheries Service.)

catch and shuck and eviscerate live scallops at
sea (Anon., 1968; Anon., 1969 ; Cummins and
Rivers, 1970; Cummins, 1971).

Insofar as the resource is concerned, the fol-
lowing is pertinent to the fishery. Catches of
calico scallops are considered commercially sig-
nificant when 20 bu (in the shell) or more are
caught per hour. Furthermore, to be harvest-
able, these scallops should be 40 mm (1.6 inches)
in shell diameter or larger (Drummond, 1969).
The weight of a bushel of scallops in the shell
is variable and has been reported as 36 kg (80
lb.) (Drummond, 1969) and "about 70 pounds"
[31 kg] (Cummins, 1971). From 1.75 bu, an
average of about 3.6 kg (8 lb.) of meats (adduc-
tor muscles) can be obtained, but this figure var-
ies with scallop condition and size, according to
Cummins (1971). Meats as large as 101 count

per kilogram (46 count per pound) have been
reported (Commercial Fisheries Review, 1968).
Minimum sizes of meats acceptable for hand-
shucking are 198 count per kilogram (90 count
per pound) (Cummins, 1971). Machine-pro-
cessed meats as small as 341 count per kilogram
( 155 count per pound) are large enough for com-
mercial use (Bullis)."

Uses for calico scallops are expanding. In ad-
dition to the market for scallop meats, the orange
roes are sold in Europe (Cummins, 1971). The
scallop viscera, with or without the adductor
muscles, are excellent when steamed in the shell

" Office memorandum, dated November 28, 1969, to
Acting Regional Director, Bureau of Commercial Fish-
eries Region 2, St. Petersburg, Fla., from Harvey _R.
Bullis, Jr., Director, Bureau of Commercial Fisheries
Exploratory Fishing and Gear Research Base, Pasca-
goula. Miss.

14

or deep-fried (Miller).'" The viscera, now usu-
ally discarded, can be used for animal feeds,
and the shells in poultry feed and as a filler in
concrete products (Bullis and Love, 1961). In
addition, the shells have been used for oyster
cultch.

The possibility exists that the resource may
be adversely affected if large quantities of scal-
lop shell, a natural cultch for scallop spat (see
section on Environment) , are removed from the
scallop grounds by the fishery.

lops were machine-processed in shore-based
plants located at Williston, Beaufort, and Salter
Path, N.C. In 1970, two factory-type scallop
vessels worked the North Carolina beds.

In North Carolina waters, the supply of calico
scallops fluctuates widely between years. No
scallops were available in 1962, 1963, and 1964;
but overall production increased greatly in 1966
and 1967. Again, no scallops were available in
1968 and 1969 but in 1970 scallops became avail-
able and production was resumed.

North Carolina

Calico scallops have long been known from the
vicinity of Cape Hatteras and Cape Lookout in
depths over 19 m. In April 1949, abundant
quantities of calico scallops were located in 19 m
southwest of Cape Lookout by the Institute of
Fisheries Research of the University of North
Carolina. The small size of the scallops and lack
of information on distribution and abundance
delayed development of a fishery in this area
(Chestnut, 1951).

According to Cummins (1971) , the North Car-
olina fishery began in 1959, following explora-
tions by the Bureau of Commercial Fisheries
(now the National Marine Fisheries Service).
The results of exploratory scalloping, and a de-
scription of a scallop concentration oflp Cape
Lookout in 31 to 37 m were given by Cummins,
Rivers, and Struhsaker (1962).

The North Carolina fishery was described by
Cummins ( 1971 ) . The principal scallop grounds
are located northeast and southwest of Cape
Lookout in 19 to 37 m (Cummins, Rivers, and
Struhsaker, 1962; Porter and Wolfe, in press).
The scallops were first caught with scallop dredg-
es which were soon replaced with scallop trawls
that function better than dredges on the hard
sand of North Carolina beds (Rivers, 1962a).
Although these trawls can catch up to 60 bu of
shell stock per 5-min drag, average catch-per-
boat-per-day is 400 to 600 bu (Cummins, 1971).
The scallops are deck-loaded and landed the same
day in the shell. They were all hand-shucked
in the fishing communities near Cape Lookout
until recently when increasing numbers of scal-

" George C. Miller, Zoologist, National Marine Fish-
eries Service, Southeast Fisheries Center, Miami Lab-
oratory, Miami, Fla. Personal communication, 1970.

Florida East Coast

Large quantities of calico scallops were discov-
ered by the Bureau of Commercial Fisheries off
Daytona Beach, Fla., in January 1960 (Taylor,
1967). Subsequent explorations by the Bureau
showed that the area of commercial abundance
extended from the St. Johns River south to Ft.
Pierce in 19 to 74 m of water (Cummins, 1971).
Explorations from 1960 to 1968 showed variable
areas of greatest concentration, all between 28
and 65 m (Bullis and Cummins, 1961; Drum-
mond, 1969; Roe, Cummins, and Bullis, 1971).
In this area, catch rates and meat yields are high-
est from September to December (Roe, Cum-
mins, and Bullis, 1971).

The types of vessels used to catch scallops on
the Cape Kennedy grounds have included shrimp
trawlers. New England scallopers, Chesapeake
Bay dredgers, and factory-type scallopers (Cum-
mins and Rivers, 1970; Cummins, 1971). The
scallops are caught with dredges and trawls. Al-
though Rivers (1962b) reported that "dredges
generally outfish the trawls" on the softer bot-
toms of the Cape Kennedy grounds, it was
learned from more recent trials that "the North
Carolina type scallop trawl is an excellent device
for catching scallops on the Florida grounds,
and that catch rates exceed those of smaller
dredges" (Commercial Fisheries Review, 1967).
The tumbler dredge is superior to the Georges
Bank dredge when used on the Cape Kennedy
beds (Bullis and Cummins, 1961).

An indication of catch rates and production
on the Cape Kennedy grounds may be obtained
from the following observations. A New Eng-
land scalloper with a single 2.4-m (8-ft) tumbler
dredge made catches ranging from 735 to 1,500
bu of scallops per 24-hr period (Cummins, 1971).
Factory scallopers processed a maximum of

15

about 1,816 kg (4,000 lb.) of scallop meats per
24 hr (Cummins and Rivers, 1970).

Shell stock from the Cape Kennedy grounds
has been landed at Darien, Brunswick, and St.
Marys, Ga.; and at St. Augustine, Port Canav-
eral, and Ft. Pierce, Fla. A shore-based plant
for machine-processing is located at Port Ca-
naveral.

According to one estimate, a total of 20 million
lb. (9,080,000 kg) of scallop meats could be pro-
duced annually on the Cape Kennedy grounds
by 40 vessels (National Marine Service, see foot-
note 7). Despite this potential, commercial op-
erators have had problems both in locating con-
centrations of scallops and in the use of the
mechanical shucker-eviscerators. These factors
are reflected in the production figures.

Northeastern Gulf of Mexico

Exploratory fishing by private organizations
from 1954 to 1958 located commercial concentra-
tions of calico scallops in the northeastern Gulf
of Mexico in the general area of Cape San Bias,
Fla. (University of Miami Marine Laboratory"";
Bullis and Ingle, 1959; Carpenter, 1967). Ex-
ploratory fishing by the Bureau of Commercial
Fisheries from 1957 to 1960 revealed extensive
beds of scallops in 19 to 46 m between Carra-
belle, Fla., and Mobile, Ala. Heaviest concen-
trations were in depths less than 37 m off Cape
San Bias and off Gulf Shores, Ala. (Carpenter,
1967).

Beginning in March 1958 a large bed of scal-
lops in 13 to 37 m of water northwest of Cape
San Bias was fished commercially. Scallops were
caught at first using scallop trawls and later with
dredges (Bullis and Ingle, 1959). The scallops
were landed in Panama City, Fla., and shucked
by hand (Carpenter, 1967) . By September 1958.
the yield of meat per scallop had declined to
where fishing was no longer profitable. These
scallops disappeared from the bed sometime pri-
or to the summer of 1959 (Hulings, 1961).

"" University of Miami Marine Laboratory. 1954.
Shrimp exploration - report of cruise No. 1 - trawler
Goodwill, June 17-July 10, 1954. Mar. Lab., Univ. Mi-
ami, unpublished circular 1 prepared for Tampa Shrimp
Producers' Assoc, and Fla. State Board Conserv., 3 p.,
ML 7876.

Production in the northeastern Gulf area since
1958 has been restricted by poor market price
(Bullis and Ingle, 1959), inadequate shucking
facilities (Captiva, 1966) and by fluctuating
stocks of scallops. Recently, a shore-based plant
for machine-processing was constructed at
Apalachicola, Fla.

SUMMARY

1. The calico scallop, Argopecten gibbtis, sup-
ports a small, developing fishery off the south-
eastern coast of the United States and in the
Gulf of Mexico. This report summarizes avail-
able information concerning calico scallop biol-
ogy and the fishery.

2. The calico scallop is separated from closely
related species within its range by shell char-
acteristics. Shell morphology of the calico scal-
lop varies with locality. The valves are well in-
flated and there are 17 to 23 ribs on the right
valve. Shell color is variable, usually with red
or maroon mottling or banding on a white or
yellow background. Maximum size is about
80 mm in shell diameter.

3. This species apparently is restricted to the
western North Atlantic Ocean. Its known range
is from the northern side of the Greater Antilles
and throughout the Gulf of Mexico to Bermuda
and slightly north of Cape Hatteras. It is gen-
erally found in open marine water on continental
or insular shelves. Depths of occurrence, how-
ever, range from less than 2 m to 370 m.

4. Environmental factors that probably in-
fluence distribution and/or growth of the calico
scallop include currents, temperatures, salinities,
substrates, and food supply. Scallop larvae are
transported by currents, and eddies formed by
coastal projections may cause repeated settling
of the larvae, resulting in great concentrations of
scallops near capes. Scallop beds are generally
distributed along the flowlines of currents. Bot-
tom temperatures associated with calico scallops
range from 9.9° to 33.0°C; salinities from about
31 to 37'/ r . Scallops are generally found on sand-
shell substrates, and shell may be necessary for
successful settlement of small scallops (spat).
Scallop abundance may be dependent upon plank-
ton concentration, and possibly related to up-
welling.

5. The greatest known abundance is off the
Florida east coast near Cape Kennedy. Lesser

16

concentrations are found near Cape Lookout,
N.C., and in the northeastern Gulf of Mexico
near Cape San Bias, Fla. Scallop densities may
exceed 108 per square meter (10 per square
foot). Abrupt yearly differences in scallop
abundance have been reported for the grounds
off North Carolina and in the northeastern Gulf
of Mexico.

6. Maturation and spawning time can be de-
termined from ovarian color. Spawning activity
may be controlled by water temperature. Spawn-
ing on the Cape Kennedy grounds probably oc-
curs year around, with maximum spawning in
the spring. For North Carolina waters, there is
no evidence of winter spawning.

7. The length of planktonic larval life from
fertilization to settlement is about 14 days. The
spat are about 0.25 mm in shell height when
first set. The rate of shell growth per month
decreases as size increases. Growth may vary
between areas. For the Cape Kennedy grounds,
preliminary studies indicate that scallops reach
40 to 45 mm in shell height in 6 to 8 months.
Maximum age averages 18 to 20 months and
does not exceed 24 months.

8. The causes of mass mortalities of calico
scallops are not known. Drastic water temper-
ature fluctuations and predation may be factors.
In addition, there is a postspawning die-off.

9. Numerous marine animals, including par-
asites and predators, have been listed as asso-
ciates of the calico scallop.

10. Calico scallop larvae occur at all levels in
the water column. The young scallops (spat)
attach to a variety of substrates. Swimming
ability is apparently most pronounced in small
scallops. On the bottom, scallops settle in de-
pressions or furrows.

11. Development of the fishery has been slow
and erratic due to problems related to stock
availability and processing. Greatest produc-
tion has been in North Carolina, and this is re-
lated to the proximity to shore of the scallop
grounds, and to the availability of processing
facilities. The history of the fishery in North
Carolina and in the northeastern Gulf of Mexico
indicates that in those areas, fluctuations in
stock availability from year-to-year will be a con-
tinuing problem. The apparent large concen-
trations of scallops off the Florida east coast,
and the introduction and improvement of pro-

cessing machines suggest that the harvest of cal-
ico scallops will increase in the next few years.

LITERATURE CITED

ANDERSON, V^. W., and J. W. GEHRINGER.

1965. Biological-statistical census of the species en-
tering fisheries in the Cape Canaveral area. U.S.
Fish V^^ildl. Serv., Spec. Sci. Rep. Fish. 514, 79 p.

ANDERSON, V^. W., J. E. MOORE, and H. R. GORDY.

1961. Oceanic salinities of the south Atlantic coast

of the United States, Theodore N. Gill Cruises 1-9,

1953-54. U.S. Fish Wildl. Serv., Spec. Sci. Rep.

Fish. 389, 207 p.

ANONYMOUS.

1968. A follow up on scallops - a breakthrough in
taste. Ocean Ind. 3(4) : 34-35.

1969. Shuckers for Florida calico beds - new scal-
lopers detailed. Natl. Fish. 50(1): 1-B (Apr.).

BULLIS, H. R., JR., and R. CUMMINS, JR.

1961. An interim report of the Cape Canaveral
calico scallop bed. Commer. Fish. Rev. 23(10):
1-8.
BULLIS, H. R., JR., and R. M. INGLE.

1959. A new fishery for scallops in western Florida.
Proc. Gulf Caribb. Fish. Inst., 11th Annu. Sess.,
p. 75-78.
BULLIS, H. R., JR., and T. D. LOVE.

1961. Application of steaming and vacuum to
shucking and cleaning scallops. Commer. Fish.
Rev. 23(5) :l-4.
BULLIS, H. R., JR., and J. R. THOMPSON.

1965. Collections by the exploratory fishing vessels
Orego7i, Silver Bay, Combat, and Pelican made
during 1956 to 1960 in the southwestern North
Atlantic. U.S. Fish Wildl. Serv., Spec. Sci. Rep.
Fish. 510, 130 p.

CAPTIVA, F. J.

1966. Resume of accomplishments in fishery devel-
opment made by the R/V Oregon. In Annual
report exploratory fishing and gear research, Bu-
reau of Commercial Fisheries Region 2 for fiscal
year 1964, p. 2-5. U.S. Fish Wildl. Serv., Circ. 236.

CARPENTER, J. S.

1967. History of scallop and clam explorations in
the Gulf of Me.xico. Commer. Fish. Rev. 29(1) :
47-53.

CERAME-VIVAS, M. J., and I. E. GRAY.

1966. The distributional pattern of benthic inver-
tebrates of the Continental Shelf off North Car-
olina. Ecology 47:260-270.

CHENG, T. C.

1967. Marine molluscs as hosts for symbiosis with
a review of known parasites of commercially im-
portant species. In Sir Frederick S. Russell (edi-
tor). Advances in marine biology, 5:1-424. Aca-
demic Press, New York and London.

CHESTNUT, A. F.

1951. The oyster and other mollusks in North Car-
olina, hi Harden F. Taylor (editor). Survey of

17

marine fisheries of North Carolina, p. 141-190.
The University of North Carolina Press, Chapel
Hill.
COMMERCIAL FISHERIES REVIEW.

1960. Calico scallop fishery in Florida. Commer.
Fish. Rev. 22(12) :41-43.

1962. Calico scallop explorations off North Caro-
lina: M/V "Silver Bay" Cruise 39. Commer.
Fish. Rev. 24(8) : 38-39.

1967. "Oregon" dredges scallops off Florida. Com-
mer. Fish. Rev. 29(11) :22-24.

1968. "Oregon" checks Florida's scallop grounds.
Commer. Fish. Rev. 30(12) :39-40.

1970. "Bowers" explores for scallop off Florida's
east coast. Commer. Fish. Rev. 32(6) :8-9.

CUMMINS, R., JR.

1971. Calico scallops of the southeastern United
States 1959-69. Natl. Mar. Fish. Serv., Spec. Sci. ^
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CUMMINS, R., JR., and J. B. RIVERS.

1970. Calico scallop fishery of southeastern U.S.
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CUMMINS, R., JR., J. B. RIVERS, and P. J.
STRUHSAKER.

1962. Exploratory fishing off the coast of North
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Fish. Rev. 24(1): 1-9.
DRUMMOND, S. B.

1969. Explorations for calico scallop, Pecten gibbus,
in the area off Cape Kennedy, Florida, 1960-66.
Fish. Ind. Res. 5:85-101.

GAUL, R. D., R. E. BOYKIN, and D. E. LETZRING.

1966. Northeast Gulf of Mexico hydrographic sur-
vey data collected in 1965. Texas A&M Univ.,
Dep. Oceanogr. Proj. 286-D, Ref. 66-8T, 202 p.

GRASSLE, J. F.

1967. Influence of environmental variations on spe-
cies diversity in benthic communities of the Con-
tinental Shelf and Slope. Ph.D. thesis, Duke
Univ., Durham, N.C., 195 p.

GRAY, I. E., M. E. DOWNEY, and M. J. CERAME-
VIVAS.

1968. Sea-stars of North Carolina. U.S. Fish
Wildl. Serv., Fish. Bull. 67:127-163.

HULINGS, N. C.

1961. The barnacle and decapod fauna from the

nearshore area of Panama City, Florida. Quart.

J. Fla. Acad. Sci. 24:215-222.
HULINGS, N. C, and D. W. HEMLAY.

1963. An investigation of the feeding habits of two
species of sea stars. Bull. Mar. Sci. Gulf Caribb.
13:354-359.

HUTTON, R. F.

1964. A second list of parasites from marine and
coastal animals of Florida. Trans. Am. Microsc.
Soc. 83:439-447.

KIRBY-SMITH, W. W.

1970. Growth of the scallops, Argopecten irradians
concentricus (Say) and Argopecten gibbus
(Linne), as influenced by food and temperature.

Ph.D. thesis, Duke Univ., Durham, N.C., 127 p.
LYLES, C. H.

1969. Fishery statistics of the United States 1967.
U.S. Fish Wildl. Serv., Stat. Dig. 61, 490 p.
MELLON, D., JR.

1969. The reflex control of rhythmic motor output
during swimming in the scallop. Z. Vgl. Physiol.
62:318-336.
MOE, M. A., JR.

1963. A survey of offshore fishing in Florida. Fla.
State Board Conserv. Mar. Lab. Prof. Pap. Ser. 4,
117 p.
NEUMANN, A. C.

1965. Processes of recent carbonate sedimentation
in Harrington Sound, Bermuda. Bull. Mar. Sci.
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PARKER, R. H.

1956. Macro-invertebrate assemblages as indicators
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1960. Ecology and distributional patterns of marine
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H. Van Andel (editors), Recent sediments, north-
west Gulf of Mexico, 1951-1958, p. 302-837. Am.
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PEQUEGNAT, W. E., and L. H. PEQUEGNAT.

1968. Ecological aspects of marine fouling in the
northeastern Gulf of Mexico. Texas A&M Univ.,
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PORTER, H. J., and D. A. WOLFE.

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mercial fishing grounds for the calico scallop,
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PULLEY, T. E.

1952. A zoogeographic study based on the bivalves
of the Gulf of Mexico. Ph.D. thesis, Harvard
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RICE, W. H., and L. S. KORNICKER.

1965. MoUusks from the deeper waters of the north-
western Campeche Bank, Mexico. Publ. Inst. Mar.
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RIVERS, J. B.

1962a. A new scallop trawl for North Carolina.

Commer. Fish. Rev. 24(5) : 11-14.
1962b. New scallop trawl developed for hard-bot-
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ROE, R. B., R. CUMMINS, JR., and H. R. BULLIS, JR.
1971. Calico scallop distribution, abundance, and
yield off eastern Florida, 1967-1968. Natl. Mar.
Fish. Serv., Fish. Bull. 69:399-409.
SASTRY, A. N.

1962. Some morphological and ecological differen-
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Aeqjiipecten irradians Lamarck and Aegidpecten
gibbus Dall from the Gulf of Mexico. Quart. J.
Fla. Acad. Sci. 25:89-95.
SINDERMANN, C. J.

1971. Predators and diseases of commercial marine
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Union, Annu. Rep. 1970, 35-36.

18

SPRINGER, S., and H. R. BULLIS, JR.

1956. Collections by the Oregon in the Gulf of
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STRUHSAKER, P.

1969a. Demersal fish resources: composition, dis-
tribution, and commercial potential of the Conti-
nental Shelf stocks off southeastern United States.
Fish. Ind. Res. 4:261-300.

1969b. Observations on the biology and distribu-
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(Pisces: Dasyatidae). Bull. Mar. Sci. 19:456-481.

TAYLOR, C. B., and H. B. STEWART, JR.

1959. Summer upwelling along the east coast of
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TAYLOR, D. M.

1967. Billion-dollar scallop find? Ocean Ind.
2(12):20-24.

VERNBERG, F. J., and W. B. VERNBERG.

1970. Lethal limits and the zoogeography of the
faunal assemblages of coastal Carolina waters.
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WALLER, T. R.

1969. The evolution of the Argopecten gibbns stock
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Tertiary and Quaternary species of eastern North
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WEEKS, A.

1970. Bureau of Commercial Fisheries Tropical
Atlantic Biological Laboratory progress in re-
search 1965-'69 Miami, Florida. U.S. Fish Wildl.
Serv., Circ. 344, 65 p.

WELLS, H. W., and I. E. GRAY.

1960. Summer upwelling off the northeast coast of
North Carolina. Limnol. Oceanogr. 5:108-109.

WELLS, H. W., and M. J. WELLS.

1961. Three species of Odostomia from North Car-
olina, with description of new species. Nautilus
74(4):149-157.

1962. The polychaete Ceratonereis tridentata as a
pest of the scallop Aequipecten gibbus. Biol. Bull.
(Woods Hole) 122:149-159.

WELLS, H. W., M. J. WELLS, and I. E. GRAY.

1961. Food of the sea-star Astropecten articidatics.

Biol. Bull. (Woods Hole) 120:265-271.
1964. The calico scallop community in North Car-
olina. Bull. Mar. Sci. Gulf Caribb. 14:561-593.
ZAHL, P. A.

1969. The magic lure of sea shells. Natl. Geogr.
135:386-429.

GPO 985-0 18

19

WHOI [ ibrary - Serials

5 WHSE 01836

621. Predation by sculpins on fall chinook salmon,
Oncorhyncltiis tshawtitscha, fry of hatchery or-
igin. By Benjamin G. Patten. February 1971,
iii + 14 pp., 6 figs., 9 tables.

622. Number and lengths, by season, of fishes caught
with an otter trawl near Woods Hole, Massa-
chusetts, September 1961 to December 1962.
By F. E. Lux and F. E. Nichy. February 1971,
iii + 15 pp., 3 figs., 19 tables.

623. Apparent abundance, distribution, and migra-
tions of albacore, Thioinus alalungn, on the North
Pacific longline grounds. By Brian J. Rothschild
and ^larian Y. Y. Yong. September 1970, v -(-
37 pp., 19 figs., 5 tables.

624. Influence of mechanical processing on the quality
and yield of bay scallop meats. Bv N. B. Webb
and F. B. Thomas. April 1971, ii'i + 11 pp., 9
figs., 3 tables.

625. Distribution of salmon and related oceanographic
features in the North Pacific Ocean spring 1968.
By Robert R. French, Richard G. Bakkala, Ma-
sanao Osako, and Jun Ito. March 1971, iii -)-
22 pp., 19 figs., 3 tables.

626. Commercial fishery and biology of the fresh-
water shrimp, Macrohracliium, in the Lower St.
Paul River, Liberia, 1952-53. By George C. Mil-
ler. February 1971, iii + 13 pp., 8 figs., 7 tables.

627. Calico scallops of the Southeastern United States,
1959-69. By Robert Cummins, Jr. June 1971,
iii + 22 pp., 23 figs., 3 tables.

628. Fur Seal Investigations, 1969. By NMFS, Ma-
rine IMammal Biological Laboratory. August
1971, 82 pp., 20 figs., 44 tables, 23 appendi.x A
tables, 10 appendix B tables.

629. Analysis of the operations of seven Hawaiian
skipjack tuna fishing vessels, June-August 1967.
Bv Richard N. Uchida and Ray F. Sumida.
March 1971, v + 25 pp., 14 figs., 21 tables. For
sale by the Superintendent of Documents, U.S.
Government Printing Office, Washington, D.C.
20402 - 35 cents.

630. Blue crab meat. I. Preservation by freezing.
July 1971, iii + 13 pp., 5 figs., 2 tables. II. Effect
of chemical treatments on acceptability. By
Jurgen H. Strasser, Jean S. Lennon, and Fred-
erick J. King. July 1971, iii -f 12 pp., 1 fig., 9
tables.

631. Occurrence of thiaminase in .some common aquat-
ic animals of the United States and Canada. By
R. A. Greig and R. H. Gnaedinger. July 1971,
iii -f 7 pp., 2 tables.

632. An annotated bibliography of attempts to rear
the larvae of marine fishes in the laboi-atory. By
Robert C. May. August 1971, iii + 24 pp.^ 1 ap-
pendix I table, 1 appendix II table. For sale by
the Superintendent of Documents, U.S. Govern-
ment Printing Office, Washington, D.C. 20402 -
35 cents.

633. Blueing of processed crab meat. II. Identification
of some factors involved in the blue discoloration
of canned crab meat Callinectes sapidus. By
Melvin E. Waters. May 1971, iii + 7 pp., 1 fig!,

3 tables.

634. Age composition, weight, length, and sex of her-
ring, Clupea paUasii, used for reduction in Alas-
ka, 1929-66. By Gerald M. Reid. July 1971,
iii + 25 pp., 4 figs., 18 tables.

635. A bibliography of the blackfin tuna, Thumnis
aflanticiis (Les.son). By Grant L. Beardsley and
David C. Simmons. August 1971, 10 pp. For
sale by the Superintendent of Documents, U.S.
Government Printing Office, Washington, D.C.
20402 - 25 cents.

636. Oil pollution on Wake Island from the tanker
R. C. Sto)ier. By Reginald M. Gooding. May
1971, iii -f- 12 pp., 8 figs., 2 tables. For sale by
the Superintendent of Documents, U.S. Govern-
ment Printing Office, Washington, D.C. 20402 -
Price 25 cents.

637. Occurrence of larval, juvenile, and mature crabs
in the vicinity of Beaufort Inlet, North Carolina.
By Donnie L. Dudley and Mayo H. Judy. August
1971, iii + 10 pp., 1 fig., 5 tables. For sale by
the Superintendent of Documents, U.S. Govern-
ment Printing Office, Washington, D.C. 20402 -
Price 25 cents.

638. Length-weight relations of haddock from com-
mercial landings in New England, 1931-55. By
Bradford E. Brown and Richard C. Hennemuth.
August 1971, V + 13 pp., 16 fig., 6 tables, 10
appendix A tables. For sale by the Superintend-
ent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402 - Price 25 cents.

639. A hydrographic survev of the Galveston Bay
system, Texas 1963-66. By E. J. Pullen, W. L.
Trent, and G. B. Adams. October 1971, v 't-
is pp., 15 figs., 12 tables. For sale by the Super-
intendent of Documents, U.S. Government Print-
ing Office, Washington, D.C. 20402 - Price 30
cents.

640. Annotated bibliography on the fishing industry
and biology of tlie blue crab, Callinectes sapidus.
By Marlin E. Tagatz and Ann Bowman Hall.
August 1971, 94 pp. For sale by the Superinten-
dent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402 - Price $1.00.

641. Use of threadfin shad, Dorosoma petenense, as
live bait during experimental pole-and-line fish-
ing for skipjack tuna, Katsuwo7ius pelamis, in
Hawaii. By Robert T. B. Iversen. August 1971,
iii -I- 10 pp., 3 figs., 7 tables. For sale by the
Superintendent of Documents, U.S. Government
Printing Office, Washington, D.C. 20402 - Price
25 cents.

642. Atlantic menhaden Brevoortia tyrannus resource
and fishery — analysis of decline. By Kenneth
A. Henry. August 1971, v -f 32 pp., 40 figs., 5
appendix figs., 3 tables, 2 appendix tables. For
sale by the Superintendent of Documents, U.S.
Government Printing Office, Washington, D.C.
20402 - Price 45 cents.

646. Dissolved nitrogen concentrations in the Colum-
bia and Snake Rivers in 1970 and their effect on
Chinook salmon and steelhead trout. By Wesley
J. Ebel. August 1971, iii + 7 pp., 2 figs., 6
tables. For sale by the Superintendent of Doc-
uments, U.S. Government Printing Office, Wash-
ington, D.C. 20402 - Price 20 cents.

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