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. Jay D. Andrews

Virginia Institute of Marine Science Gloucester Point, Virginia

. Kenneth J. Boss

Museum of Comparative Zoology Harvard University Cambridge, Massachusetts

. A. F. Chestnut

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

. James E. Hanks

Bureau of Commercial Fisheries Biological Laboratory Milford, Connecticut

. G. Robert Lunz

Bear Bluff Laboratories Wadmelaw Island South Carolina

. J. C. Medcof

Fisheries Research Board of Canada Biological Station St. Andrews, N. B., Canada

. D. Winston Menzel

Oceanographic Institute Florida State University Tallahassee, Florida

Arthur S. Merrill




Daniel B. Quayle Fisheries Research Board of Canada Nanaimo, B. C., Canada

. Sammy M. Ray

A. & M. College of Texas Marine Laboratory Galveston, Texas

. Aaron Rosenfield

Bureau of Commercial Fisheries Biological Laboratory Oxford, Maryland

. Rudolf S. Scheltema

Woods Hole Oceanographic Institution Woods Hole, Massachusetts

. Carl J. Sindermann

Bureau of Commercial Fisheries Biological Laboratory Oxford, Maryland

. Albert K. Sparks

College of Fisheries University of Washington Seattle, Washington

Harry W. Wells

Department of Biological Sciences University of Delaware

Newark, Delaware

Bureau of Commercial Fisheries Biological Laboratory

Oxford, Maryland





Published for the National Shellfisheries Association by

Economy Printing Co., Inc., Easton, Maryland

June 1967


OF THE NATIONAL SHELLFISHERIES ASSOCIATION Volume 57 June 1967 CONTENTS List of Abstracts by Author of Technical Papers Presented at the 1966 NSA Convention 0000000000. UV Abstracts: NSA. Comvenmtionr o....ccecccsseeceeee Ia eee tan SEE Ret Oe lle rn os a meee wy ne eee She. ae 1 PACifiCRCOAaSt ey SECU ON ee eee CoS oe Stn eee Sn eee en eee 6 Jay D. Andrews Problems ini Shellfish Proc ucts orn sere ere cece eee ere 2s 9 Anthony Calabrese and Harry C. Davis Effects of “Soft’? Detergents on Embryos and Larvae of the American Oyster (Crassostrea virginica) ................. Wier iets) ee SNR eee ea, eT OA on tape see ODL William N. Shaw and George T. Griffith | Effects of Polystream and Drillex on Oyster Setting in Chesapeake Bay and Chincoteague Bay .......... BR A ed eh ae re ewe Set ee ee re 17 Gregory J. Tutmark, Wariboko Q. B. “West, i mennethe K. Chew Preliminary Study on the Use of Bergman-Jefferts Coded Tags on Crabs 24 Kenneth Sherman and Robert D. Lewis Seasonal Occurrence of Larval Lobsters in Coastal Waters of Central Maine 20. ~=27 Paul Chanley and Robert F. Normandin Use of Artificial Foods for Larvae of the Hard Clam, Mercenaria Mmercemarid (La) occ cose 31 Jay D. Andrews Interaction of Two Diseases of Oysters in Natural Waters .... sean pt tac anaes ean cinsea nee SEO) Stanley C. Katkansky, Albert K. Sparks, and Kenneth K. Chew Distribution and Effects of the Endoparasitic Copepod, Mytilicola orientalis, on the Pacifici@ystersiCrassostred gigas, ,Oml they PaCitic COS bees cece ee 50 Leonard M. Bahr and Robert E. Hillman Effects of Repeated Shell Damage on Gametogenesis in the American Oyster, CRASSOSERE OM UUN OT NACC wn WG TIC DTA) eee erates earner an eee ee eee Bere csas OS) Warren S. Landers Infestation of the Hard Clam, Mercenaria mercenaria, by the Boring Polychaete Worm, ZOU COTO GUA CL Cee ee Pe ac ey et ne rele nse a 63 John D. Davis Polydora Infestation of Arctic Wedge Clams: A Pattern of Selective Attack 0 67 Norman R. Tufts fhopical@iZabeline ofa Shelli sigs ae ee eee ee 73 Johnes K. Moore and Nelson Marshall An Analysis of the Movements of the Bay Scallop, Aequipecten irradians, in a Shallow Estuary .. Ss Soopite os ooes eae vei sits aa cereal nts pees th 77 S. B. Saila, J. B. Flowers, and M. ‘T. ‘Cannario. Factors Affecting the Relative Abundance of Mercenaria mercenaria in the Providence River, Rhode Island .............. aE acetate ape ero Scns area ees ee ee : 83 - Allan M. Barker and Arthur S. Merrill Total Solids and Length-Weight pages of the Surf Clam, Spisula solidissima 000... 90 Association eAttairs = Fa Shc ea re eR ee eh ee a cs S/T



Allan M. Barker and Thomas M. Groutage Statistics of the New Jersey Surf Clam Fishery 1965 on eesescsssesessstntsneesetessneineeeeennennmentey sesunetaeeiee

Paul Chanley Comparative Study of Twenty-Three Species of Bivalve Larvae

John L. Dupuy, Albert K. Sparks, Kenneth K. Chew, and Benny C. C. Hsu A Source of Paralytic Shellfish Toxin in Sequim Bay, Washimgton 22... ccccctsssmneseestsntemeineunee

S. Y. Feng Further: Studies sin) Cl arm: De pura tl om cise ce cee eee cece ecm tara ae a

David R. Franz Further Studies on Physiological Variation Among Populations of CO) 2) Ce a) DD US} Pe ge ee eee

R. W. Menzel Studies of the Fi and F. Hybrids of the Northern and Southern Qualhhoge Clams) tee a ee a a ieee ge ee ee ee

John A. Mulhern A Preliminary Report on Mortality and MSX Levels in Oyster Spat oc. cceccecsssessscssssessnessemesseinetne

| Ernst Muller Electron Microscope Studies Of Mimchimicd MelsOmi occa ccccncccsnvscceeccnoceenscsenesnssicsnsnenssnnssinesiipsnstiiinnsensssinssinstimeneecss

| Edwin H. Powell and Jay D. Andrews Progress in Artificial Culture of Virginia Oysters ...

D. B. Quayle and T. Terhune ASPlanktony Sam plers for ©y:Ste ry Wseh reve ccc see as acct cs ccc aerate cee ence scares essere

John W. Ropes The Locomotion and Behavior of Surf Clams, Spiswla SOUUGiSSV ccc ccccccccosseesensvoonesssessssnsnnesenssetnsiionnnneeene

John W. Ropes, Arthur S. Merrill, and Thomas M. Groutage MarkingeSurtsClamsefors Growth Cui CG te cst ee ee eee

John W. Ropes, Robert M. Yancey, and Arthur S. Merrill The Growth of Juvenile Surf Clams at Chincoteague Inlet, Virgimia cette

Carl N. Shuster, Jr. A Three-Ply Representation of the Major Organ Systems Of A&A QUA aU once cccessssnsentineennenncemeeee

Harold W. Sims, Jr. Whe PresentStatus/of Florida: Spiny, Mobster RSC archy 2oecc esses cret cer ceeeeeceetcertereremereer tees seeree coereeeesnese eters

Webb Van Winkle Ciliary Activity and Oxygen Consumption in Pelecypod Gill Tissue .......0.00-...-...

Robert M. Yancey IN VELEN AEN COVE LEA COY A RATS OL SANT © LOVE 9 UT Se eF sO 0 eee ee



John Mark Dean, Ford A. Cross, and Scott W. Fowler Metabolism Of Zn im Crustacea oucccccccscecsscceenecseenees

John L. Dupuy and Albert K. Sparks Gonyaulax (Catenella?), Its Growth, Toxin Production and Relationship with Bivalve Mo lusks o...cccccccccesesssccsssseeseneemesniineeinse a

W. Jakubowski and G. J. Vasconcelos Studiesuon Wet: Storage of Oyster andliClamiShellstochk: sire ce csccc cases ste ee se cecrses eee teeter nena

Benny C. C. Hsu and Albert K. Sparks The Identification and Methods of Reproduction of the Causative Organism of Shellfish Toxicity in Washington State Ca EP aS St a ca he BS ents Oe sacri ci an fe evant eae eee ec Ee eet oe :

Gilbert B. Pauley and Roy E. Nakatani The Uptake of the Radioisotope ®°Zn by Various Tissues of the Freshwater Mussel, Anodonta CalifOrniensis Lea oncccccccccsssscssecsssessinesiunssinnssicesiusttinenneceiscineee

W. L. Templeton Transport and Distribution of Radioactive Effluents in Coastalcand)EstuarinesWatersof the) Ui Kye cee ntemeeeoennes ee eee

Proceedings of the National Shellfisheries Association

Volume 57 June 1967



Allan M. Barker and Thomas M. Groutage

U. 8S. Bureau of Commercial Fisheries Biological Laboratory Oxford, Maryland

New Jersey landings of surf clams (Spisula solidissima) have increased greatly since 1943, while the contributions of other middle Atlantic states have declined and are now of minor signifi- cance. The marked increase in landings from 1957 (15 million pounds of meat) to 1965 (43.7 million pounds) can be attributed to the New Jersey fish- ery. Greater demand for the product and _ in- creased gear efficiency have both played their part in this rise.

Since 1959, surf clam fishing effort has stabi- lized and is concentrated in the area between Point Pleasant and Barnegat Lightship. A fleet of about 50 boats is based at Point Pleasant, with a few (7-9) boats at Cape May-Wildwood and Barnegat Inlet. In 1965 considerable effort was expended near Barnegat Lightship. In the spring a dense bed of small clams inshore at Cape May was heavily exploited. Record landings in 1965 were due in part to large catches of these small clams. Landings at Cape May exceeded those at Point Pleasant in March. Mean lengths of total samples by month at Point Pleasant were con- sistent at 6 inches throughout 1965. Mean lengths of Cape May samples were 5 to 6 inches.

Average catch and effort at Point Pleasant in 1965 reached a low of 607 pounds per hour in February and a high of 744 pounds per hour in September. Observations on commercial vessels at sea revealed that the amount of clams dis- carded is usually insignificant and rarely exceeds one bushel per trip.

Length-meat weight ratios indicated that meats from inshore Cape May clams were similar in weight to meats from offshore Point Pleasant clams of the same shell length. Monthly per cent

solids of clams from Point Pleasant and Cape May were determined in 1965 and values were not significantly different between the two locations.


Paul Chanley

Virginia Institute of Marine Science Wachapreague, Virginia

Larvae of 23 species of bivalves have been reared in the laboratory and studied comparative- ly. Photomicrographs, keys, graphs, and tables are offered as aids to their identification. Char- acters of particular importance in _ identifying larvae include: hinge line length, size and shape of umbo, length-height relationship, length and shape of anterior and posterior ends as well as color or texture. In a few species hinge teeth are distinctive.


John L. Dupuy, Albert K. Sparks, Kenneth K. Chew, and Benny C. C. Hsu

College of Fisheries, University of Washington Seattle, Washington

The seasonal rise in shellfish toxicity along the Strait of Juan de Fuca from 1961 to 1965, parti- cularly in Sequim Bay, was coincident with the increased abundance of the dinoflagellate, Gon- yaulax sp. (catenella?) and the appearance of toxin in plankton extracts. Experiments with unialgal mass cultures of Gonyaulax sp. isolated from Sequim Bay gave definite evidence that Gonyaulax is a primary source of toxin in this area and in the Strait of Juan de Fuca.

Final concentrations of Gonyaulax sp. varied when grown under similar conditions and in the


same batch of medium. Extracts of Gonyaulazx sp. grown in similar and different culture media were found to yield variable amounts of paralytic shellfish poison.


Department of Oyster Culture, Rutgers University New Brunswick, New Jersey

In a study of elimination of viral particles by hard clams, Mercenaria mercenaria, two bacterio- phages, Staphylococcus aureus phage 80 and Escherichia coli phage S-13, were used as virus models. Hard clams experimentally contaminated with the two phages were treated in recirculat- ing and flow-through seawater systems. The sea water, with salinities ranging from 20 to 22 ppt, was irradiated by UV light before reaching the clams. The experiments were carried out under temperatures ranging from 10° to 20°C and flow rates from 50 to 150 gallons per hour. The data reveal that the purification rates of the two bacteriophages, by hard clams, were independent of temperatures (10°, 12°, 15°, 18° and 20°C), and flow rates (50, 100 and 150 gallons per hour). The course of elimination is characteristically an initial rapid removal followed by a more gradual, 6-day attrition of the viral particles. The data also suggest that the clam eliminates the two bacterio- phages at different rates: S. aureus phage 80, the less hardy of the two, is eliminated at a much faster rate than is the H. coli phage S-13 which resembles poliomyelitis virus in size, shape and nucleic acid content.

!'This investigation is supported in whole by Public Health Service Research Grant EF 00671.

2 Present address: Marine Research Laboratory, University of Connecticut, Noank, Connecticut 06340.


David R. Franz!

Department of Zoology, Rutgers University New Brunswick, New Jersey

Physiological studies in the field and laboratory were carried out on oyster drills (Urosalpinx cinerea Say) from Long Island Sound, Delaware Bay, and Bogue Sound, N. C. and on oyster drills (U. c. follyensis Baker) from the Eastern Shore of Virginia. Short-term growth studies using drills


reared from egg cases showed that the Eastern Shore drills grew significantly faster than the Long Island and North Carolina populations. However, the rate of oyster consumption by all three populations was the same.

Analysis of the cumulative feeding and fecundity curves of mature Long Island and Eastern Shore drills maintained in trays on the Cape Shore tide flats indicated that these drills con- sumed more oysters and produced more egg cases than similarly held New Jersey and North Carolina populations. Temperatures above 25°C did not appear to inhibit feeding or fecundity of drills in trays.

Laboratory studies on feeding rates of drills held at temperatures ranging from 10-30°C in- dicated that the Eastern Shore drills fed at higher rates than the other three populations, especially at low temperatures.

In the laboratory, the Long Island drills pro- duced many more egg cases than the other popul- ations at temperatures from 10 through 26°C. The New Jersey and North Carolina drills did not differ from each other in this regard and both produced fewer egg cases than the Eastern Shore drills at temperatures above 15°C.

These studies clearly show the higher fecundity of the Long Island drills relative to all other populations studied. Physiological differences in the Eastern Shore population have been demon- strated in growth rate, feeding rate and the num- ber of egg cases produced per clutch.

| Present address: Department of Zoology, Univer- sity of Connecticut, Storre, Connecticut 06268.


R. W. Menzel Florida State University

During the first half of five years’ observa- tions of northern and southern parents and re- ciprocal hybrids, the southern species grew fastest and the northern slowest. Growth rates of the hybrids were intermediate, but closer to the southern parent. During the latter half of the observation period the growth rates of the hybrids surpassed both parents. The F; hybrid of the cross, female Mercenaria campechiensis X male Mercenaria mercenaria, grew larger than those of a reciprocal cross.

All the 4 possible F2 crosses have been made. Although still too small for final characterization, they so far resemble the southern parent in shell morphology.



John A. Mulhern

Department of Zoology and Oyster Culture Rutgers University New Brunswick, New Jersey

Since 1958 there has been increasing evidence on the Delaware Bay Cape Shore for develop- ment of strains of oysters resistant to mortality due to Minchinia nelsoni (MSX) infection. As part of a detailed study of disease resistance, mortali- ties in two groups of spat, exposed in trays at the Cape Shore, have been monitored since July 1965. Both groups were laboratory reared; one from a stock of resistant parent oysters (old Delaware Bay stocks exposed to MSX for several years) and the other from a stock of very sus- ceptible oysters (Navesink River, N. J.). From 29 July 1965 to 23 April 1966, 75 per cent of the Nave- sink spat and 80 per cent of the Delaware Bay spat died of all causes. Histological study of periodic samples of living oysters and “gapers” are incomplete but by 14 August 1965 more than 90 per cent of all spat sampled were lightly in- fected with MSX. By October the infections in the Navesink spat were generally heavy, while more than one third of the Delaware Bay spat had rare to light infections. Interpretation of these data must await completion of the study.


Ernst Muller

New Jersey Oyster Research Laboratory anu Department of Zoology, Rutgers University New Brunswick, New Jersey

Gill tissue from living oysters showing a mod- erate or heavy infection of Minchinia nelsoni (MSX) on examination of a wet mount was fixed in Palade’s veronal-buffered osmic acid, embedded in methacrylate, and sectioned on an LKB Ultro- tome. Sections were viewed and photographed on an RCA EMU-2 (Canalco modified) electron microscope.

Vegetative stages of MSX that have been re- cognized in these preparations to date have a morphology familiar to us, in an overall sense from studies with the light microscope. The cell membrane is distinct but ragged in appearance. No locomotive organelles such as cilia, flagella, or vestiges of a flagellar apparatus such as kinetoplasts have been observed in plasmodial stages. Only capped nuclei have been seen so far.

The nucleoplasm is granular and homogeneous (i.e., without chromatin clumps). The nucleolar cap is distinguishable only by its greater electron density; no membrane separates it from the rest of the nucleoplasm. Other intranuclear structures such as spindles or “Kernstaebe’” have not yet been encountered. The nuclear envelope, which consists of two membranes, is about 25 y thick. In one collection of oysters, the outer membrane of the MSX nuclei exhibited small outpouchings or “blebs”. The significance of the blebs is not known.

MSX mitochondria are approximately spherical and relatively large. The inner mitochondrial membrane is invaginated into microtubules rather than cristae; this microtubular condition is typically, though not exclusively protozoan. Mito- chondria frequently appear in close association with nuclei. Many nuclei are surrounded by mitochondria and often appear to be indented by their mitochondrial ‘satellites’. The large num- ber and size of mitochondria, and their associa- tion with nuclei, suggest that MSX is a cell of great oxidative metabolic capacity, part of the energy from which may function in nuclear re- production.

In addition to mitochondria, the cytoplasm con- tains a background of granules, saccules, and vacuoles which for descriptive purposes may be termed endoplasmic reticulum. Imposed upon this background have always been found numerous, small (about 150 y), very dense (i.e., osmiophilic) particles. These particles bear a very strong re- semblance to certain viruses. If these are viruses, one may now only speculate about their role: perhaps they are hyperparasites or symbionts (cf., the kappa particles of Paramecium.)

It is apparent that MSX as seen through the electron microscope is cytologically complex and unusual to an extent not hitherto imagined.


Edwin H. Powell and Jay D. Andrews

Virginia Institute of Marine Science Gloucester Point, Virginia

For seven years the parasite, Minchinia nelsoni (MSX), has persistently killed oysters in Virginia and kept nearly half of our private oyster acre- age out of production. The urgent need for MSX- resistant oysters has resulted in vigorous efforts to breed such stocks by artificial culture. Phase (1) was the collection of survivors from large planted beds, heavily selected by MSX, for five


to seven years. Phase (2) involved breeding these old survivors under controlled laboratory con- ditions. Numerous larval cultures were success- fully reared in 1964 and 1965. All important stocks of selected oysters have been bred successfully. Phase (3) required nursery conditions for pro- geny which insured growth, survival and freedom from contamination by wild spatfalls. This was found in an acre-size pond with limited circula- tion. Phase (4) requires monitoring batches of progeny until evidence on resistance to MSX is available. This phase is the longest, most tedious and most demanding in terms of effort and time. All other phases have now been successfully com- pleted. Monitoring requires a mimimum of two or three years. Each progeny group is held in large legged trays in York River. Oysters are counted, measured and sampled regularly to provide dis- ease incidence and death rates. Some 25 lots of progeny and as many brood stocks are now under observation. Progeny set in 1964 are showing en- couraging results in that those from MSX-selected oysters have lower disease incidences and less mortality than controls.


D. B. Quayle and T. Terhune

Fisheries Research Board of Canada Biological Station, Nanaimo, B. C.

A plankton sampler has been designed pri- marily to sample oyster larvae uniformly in a vertical column of water. It may be used either as a spot or as a moving sampler. The apparatus requires a perforated pipe, water pump, water meter and plankton net.


John W. Ropes

U. S. Bureau of Commercial Fisheries Biological Laboratory Oxford, Maryland

The locomotion and behavior of surf clams, Spisula solidissima, were investigated to assess their possible migratory abilities. Both field and laboratory observations were included in the study.

Observations were made on beach and offshore


populations of surf clams. On beaches juvenile clams 20 to 70 mm in shell length displayed four types of activity: (1) gliding through the water (2) exhuming themselves from the exposed beach at low tide, (3) rapidly burrowing into the sub- strate as the tide flooded in, and (4) crawling over the substrate. These observations suggested that small clams may shift location, especially if bottom currents are present to carry the clams once locomotion is initiated. In the laboratory, juvenile clams propelled themselves off the bot- tom by muscular movements of the foot and glided a distance of 8 to 12 inches.

Low water temperatures resulted in reduced activity. Clams in the laboratory acclimated to a 10°C increase from 8°C within 24 hours and bur- rowed more rapidly than clams under the in- fluence of low seasonal temperatures. A 22°C rise from 8°C caused gaping, lethargy, and eventual death. Clams were frequently observed emerging frem exposed sand at low tide, but this activity has not been duplicated in the laboratory either by draining the water from the aquaria sand, heat- ing the sand surface, or applying a weight to the sand surface. Crawling, by alternately penetrat- ing the tip of the extended foot in the sand and contracting it, has been observed only infrequent- ly in either the field or laboratory.


John W. Ropes, Arthur S. Merrill, and Thomas M. Groutage

U. S. Bureau of Commercial Fisheries Biological Laboratory Oxford, Maryland

Various marking techniques were tested on surf clams, Spisula solidissima, as part of studies on population dynamics and growth. The methods of collecting large numbers of juvenile surf clams at Chincoteague Inlet, Virginia, in late 1964, apply- ing colored liquids to the shells, attaching plastic discs and tapes to the shells with adhesives, and grinding notches in the shells are described.

The colored liquids were generally unsatis- factory marks on recovered clams. Notches clear- ly delimited increments of new shell growth. New adhesives appear to be promising as a means of attaching colorful individual markers and can be used in conjunction with shell notches for plant- ing in the offshore fishery. The colorful marker improves the chance of recovering notched clams by attracting the attention of the fishermen.



John W. Ropes, Robert M. Yancey, and Arthur S. Merrill

U.S. Bureau of Commercial Fisheries Biological Laboratory Oxford, Maryland

Juvenile surf clams, Spisula solidissima, were collected, marked, planted, and recovered over an 18 month period in Chincoteague Inlet, Virginia, to obtain measurements of growth. A _ notch ground into the shell margin was used as a re- ference mark of the clam’s original shell length when planted.

Clams from the Chincoteague Point planting site grew an average of 42.1 mm in length after 18 months or about 2.4 mm per month. Slower growth (22.7 mm after 18 months or 1.3 mm per month), apparently due to unfavorable environ- mental conditions, was observed at the Assateague Cove planting site. Unmarked clams from Wallops Island increased in length from 21.1 mm to 66.2 mm in 18 months, an average of 2.5 mm per month. An analysis of variance showed no signif- icant difference between the growth of marked clams from Chincoteague Point and unmarked clams from Wallops Island. Thus, notching the shell margin of surf clams appears to be a useful method of providing accurate measurements of growth.


Carl N. Shuster, Jr.

Northeast Shellfish Sanitation Research Center PHS, DHEW Narragansett, Rhode Island

A series of semi-diagrammatic drawings have been made to outline and depict the relative posi- tions of the major organ systems in the northern quahaug, Mercenaria mercenaria L. These draw- ings can be cut out, folded, slipped together, and stapled in the hinge area to form a sequence of visualizations from the exterior to the interior of this mollusk. Additional drawings provide orienta- tion in sectional aspects.

Dissections of large quahaugs, about 12 cm in length, and sections of frozen specimens made with a diamond-blade, cut-off saw were the basis of the paper reconstruction.

These drawings were developed as a training

aid in connection with the National Shellfish Sanitation Program.


Harold W. Sims, Jr.

Florida Board of Conservation Marine Laboratory St. Petersburg, Florida

To find ways to increase production of the spiny lobster, large scale studies on its basic biology were begun in 1962. Nine cruises were made to the Yucatan Straits and northern Caribbean to study the possible Caribbean origin of Florida’s spiny lobster population. Evidence is reviewed for the year-round production of larvae in the Caribbean. Spawning in Florida appears to be more extensive in spring and summer. Be- cause of the long larval life and high natural larval mortality, rearing from eggs is not con- sidered feasible as a farming practice.


Webb Van Winkle

Department of Zoology Rutgers University New Brunswick, New Jersey

Measurements were made of ciliary activity and oxygen consumption of excised gill tissue from Crassostrea virginica, Mercenaria mer- cenaria, Modiolus demissus, and Mytilus edulis. The objective was to evaluate the influence of sal- inity, temperature, and season on these two parameters.

The cilia of gill tissue from low-salinity as com. pared to high-salinity acclimated animals beat faster at low experimental salinities. The four species are ranked as follows with respect to the ability of cilia to tolerate reduced salinities: Modiolus > Crassostrea > Mytilus > Mercenaria.

Of ecological interest is the relationship be- tween gill tissue oxygen consumption and ciliary activity. At low salinities isolated gill tissue utilized as much or more oxygen than at high salinities. Yet, at these low salinities ciliary activity was greatly reduced. If this relationship holds true for gill tissue in the intact animal, it means that there is a constant or increased expen-


diture of energy under conditions where the food gathering machinery is working less efficiently.


Robert M. Yancey

U. 8S. Bureau of Commercial Fisheries Biological Laboratory Oxford, Maryland

Studies of the biology and of the population dynamics of the surf clam, Spisula solidissima Dillwyn, are the two major divisions of the Surf Clam Program at the Bureau of Commercial Fish- eries Biological Laboratory, Oxford, Maryland. Advances in our knowledge of the clam have been significant in recent years.

The annual reproductive cycle has been deter- mined for New Jersey clams. Spawning in July is usually followed by a second but minor spawning in the Fall. Sexual maturity appears to be reached at a shell length of about 2-1/2 inches. Growth of


juvenile surf clams has been followed at Chin- coteague Bay, Virginia, for the past 18 months by sampling a beach population, and by planting and recovering marked clams.

In two 30-day surf clam cruises in 1965, a total of 591 stations were occupied in a 25,000-square- mile area extending from Montauk Point, Long Island, to Cape Hatteras, North Carolina. The number of clams taken, size frequencies, bottom type, associated organisms, temperatures, and salinities were recorded for each station.

Catch data were obtained during 1,400 inter- views with boat captains, and 14,000 clams from 785 commercial landings were measured at Point Pleasant, Barnegat, and Cape May-Wildwood, New Jersey, in 1965. The amount of clams dis- carded at sea by fishermen was observed on in- dividual trips and determined to be of minor im- portance.

The relation of length to meat-weight was established for each month of 1965 in samples from the fishery. Seasonal changes in clam meat condition, as measured by percentage solids, were also determined in 1965.


METABOLISM OF ®&Zn IN CRUSTACEA! John Mark Dean, Ford A. Cross’, and

Scott W. Fowler?

Biology Department, Battelle Memorial Institute Pacific Northwest Laboratory Richland, Washington

The metabolism of ®°Zn has been studied in the shore crab, Hemigrapsus nudus. Data for the up- take of the radionuclide from sea water, retention, and sites of concentration will be presented. Also the uptake, retention, and localization of Zn from sea water by the benthic amphipod, Anonyx sp., and the pelagic euphausid, Huphausia pacifica, will be shown. The relationships between the ecology of these three species of Crustacea and their metabolism of this important radionuclide will be discussed.

‘This paper is based on work performed under United States Atomic Energy Commission Con- tract AT 45-1)-1830.

*A graduate student in the Department of Oceano- graphy, Oregon State University, supported by the predoctoral AEC Richland Graduate Fellow- ship program.


John L. Dupuy and Albert K. Sparks

College of Fisheries, University of Washington Seattle, Washington

Experiments with unialgal mass cultures of Gonyaulax isolated from Sequim Bay gave de- finite evidence that Gonyaulax is a_ primary source of toxin in this area and in the Strait of Juan de Fuca.

Under identical conditions of culture (with the exception of light intensity) production of para- lytic shellfish toxin was found to be inversely pro- portional to regeneration time.

With an increase in the period of time after the


cells have reached the end of the log reproduction phase the amount of toxin present per unit num- ber of cells decreased.

The uptake of paralytic shellfish toxin by shell- fish has been demonstrated. Very low concen- trations of Gonyaulax (about 20 cells/ml) had to be used without rejection becoming apparent.

The forms of Gonyaulax in culture have been described over a 96-day period.


W. Jakubowski and G. J. Vasconcelos

USPHS Shellfish Sanitation Laboratory Gig Harbor, Washington

Studies were initiated to determine the effect of wet storage on the sanitary quality of shellfish. A float capable of holding approximately 5 bush- els of shellfish was anchored over a commercial oyster bed in Burley Lagoon. Shellfish and water samples were examined at the low, mid and high points of the tide for a 24-hour period and at the low and high tides for another 24 hours. Four experiments utilizing Pacific oysters (Crassostrea gigas) and Manila clams (Venerupis japonica) were completed during the winter and spring months of 1965-66 and one experiment was per- formed in July, 1966. The shellfish showed a rapid accumulation-elimination response to fluctuations in water bacterial density. In all experiments the coliform MPN’s, fecal coliform MPN’s and plate counts of shellfish and water samples varied in- versely with the salinity. Salinity observations could not always be correlated with the stage of the tide. This may have been due to the presence of a large, strong eddy current causing inter- mittent influxes of fresh water into the float area. Further experiments employing constant re- cording salinity and temperature devices and an intensified sampling schedule will be conducted.


Benny C. C. Hsu and Albert K. Sparks

College of Fisheries, University of Washington Seattle, Washington

Paralytic shellfish toxicity studies in the State of Washington have been conducted for the past

six years. The causative organism was found to be a chain-forming dinoflagellate. This organism is similar in appearance to Gonyaulax catenella Whedon and Kofoid and has the same plate formula of 4’, Oa, 6”, 6, 6”, 1p, 1””’. However, some morphological differences were noted. The organism studied in Washington contains extra left accessory sulcal plates and two antapical wings instead of two short antapical spines. The girdle curtain (curtain fin) is a delicate mem- brane attached to both ridges of the girdle but is not always present. The relative size, shape, and position of the plates are also slightly different. The methods of reproduction of this organism are not yet fully understood. Examinations of pure cultures and field samples have thus far shown four methods of reproduction: (1) binary fission with theca, (2) division of protoplast into two daughter cells after escaping from theca, (3) cyst formation, and (4) development of autospores.


Gilbert B. Pauley and Roy E. Nakatani

Biology Department, Battelle Memorial Institute Pacific Northwest Laboratory Richland, Washington

Marine mollusks are used extensively as in- dicators of radioisotopes in the environment. How- ever, very little work has been done utilizing freshwater mollusks as radionuclide indicators.

Two separate experiments using the freshwater mussel, Anodonta californiensis Lea, were set up to determine (1) if this animal has an affinity for 65Zn, (2) what effect the amount of isotope avail- able in the environment has on the accumulation of it by the mussel and (3) which tissues of the mussel’s body concentrate ®Zn.

In the first experiment, utilizing ®°Zn concentra- tions of 1 ,4Ci/1, 10 wCi/1, and 100 wCi/I, it was found that the total body burden accumulated by these mussels was approximately linear to the amount of radioisotopes available in the environ- ment.

The second experiment ran for 36 days, using 100 Ci/1 of © Zn. The tissues of the mussel’s body accumulated ®Zn both by wCi/g and total tissue burden in the following order: (1) gills, (2) man-


tle and palps, (3) body mass including the diges- tive gland, digestive tract and gonad, (4) ad- ductor muscles and (5) foot. At the termination of the experiment, the mussels were still ac- cumulating ®Zn from the environment, as they had not come to equilibrium, and had an average total body burden (soft parts) of approximately 100 pCi.

Autoradiographs were made of four different areas of the mussels. The Leydig cells contained little or no ®Zn. Moderate concentrations of the radioisotope were found in the gonads, gonadal ducts, outer mantle epithelium, intestinal and rectal epithelium, and the adductor muscles. Heavy concentrations of Zn were observed in the kidney epithelium, the leucocytes, and the pericardial fluid.

The order of concentration of stable zinc and 65Zn was the same within the various tissues of the mussel.

1This paper is based on work performed under United States Atomic Energy Commission Con- tract AT(45-1)-1830.



W. L. Templeton

Biology Department, Battelle Memorial Institute Pacific Northwest Laboratory Richland, Washington

The distribution and transport of radionuclides discharged to the Irish Sea from the chemical re- processing plant at Windscale is discussed in terms of the hydrography and the composition of seabed material. Seaweed surveys around the U.K. coastline compare the background fallout levels with those in the Irish Sea and indicate the limit of Windscale contamination to less than 200 miles.

In the Blackwater Estuary, M.A.F.F. surveys of the distribution of ®Zn are presented in relation to the contamination of the commercial oyster beds, and discussed in relation to the hydro- graphic conditions.

‘Work carried out while employed by the U.K.A.E.A. and previously presented, in part, at the I.A.E.A. Symposium on Disposal of Radioac- tive Wastes to the Oceans, Seas and Surface Water, 1966. Vienna (in press).

Proceedings of the National Shellfisheries Association

Volume 57 June 1967



Twenty years ago I attended my first oyster con- vention. A year later I gave a paper on setting in the James River. Now I am even more concerned about understanding the mechanisms of wild spat- fall since setting has begun failing in the fabulous James River seedbeds.

I want to take as my topic production, which is the theme chosen for this convention, and as my guide I will use the program in your hands. Al- most 90 years ago Prof. Wm. K. Brooks of Johns Hopkins University began marine studies in Chesapeake Bay on Fort Wool the small island on the Chesapeake side of the Hampton Roads bridge-tunnel as you leave Norfolk. He noted the abundance of oyster drills around the island and you will find these predators still listed on our program in 1966. We are testing whether or not a chemical called Polystream can be used success- fully in waters other than Long Island Sound.

Other familiar old subjects appear on the pro- gram. In the late forties Dr. Korringa of Holland was our guest and told us about shell disease of oysters in Europe. Since then we have discovered or acquired several diseases of our own the most serious and famous of which is MSX. You will find this subject discussed together with an account of government programs to combat the disease. Studies of bivalve larvae were being made in the forties and are still in progress in labora- tory and field. Our knowledge of larvae, especially artificial culture of them, has advanced consider- ably in two decades.

But I don’t recall that production was a subject on our programs 20 years ago. When I came to Virginia, seed oysters sold for less than 50c a bushel and market oysters for $2 to $3. Now, from the southern states to New England, seed oysters range from $2 to $10 and market oysters from $4 or $5 to $20. Much has happened! First Mother Nature decided to demonstrate who controls the

' President’s Annual Report, delivered June 6, 1966 at the 1966 NSA meeting, in Norfolk, Va.

seas and sent a few hurricanes which ravaged all areas but particularly Long Island and New Eng- land where predators and failure of spatfalls were already pressing oyster farmers hard. The pro- gram this year offers an “explanation” of Mother Nature and the droughts she has recently inflicted upon us with disastrous results.

Then in the fifties as seed production failed in Delaware Bay, we were badly hurt by MSX which spread to Chesapeake and now has a large propor- tion of the high-salinity oyster grounds out of production in the middle Atlantic area. Production has declined precipitously.

Other subjects on our 1966 program, if not new, have become much more serious over the 20 years. The pesticides spread so liberally over our land have often ended up in our rivers. Hence the huge monitoring programs now in progress. Pollution has grown almost to the status of a national dis- aster, hence the public health scientists are busy with abatement programs in big new laboratories. Purification of shellfish is a growing concern and expense.

But back to production. Why can’t we produce all the shellfish our people will eat? And why have our products changed from a poor man’s food to almost luxury items? Any of you fortunate enough to have a reason to watch the stock market know that mergers of million dollar com- panies are almost daily occurrences in this coun- try. What do they seek by merger control of their products from raw materials until they are safely in the hands of consumers, and, size and diversification to protect against the unforeseen. What do we find in the shellfisheries industry ancient methods despite modern technology, small units from towns in New England to county sys- tems in the mid-Atlantic and over a hundred certi- fied producers of shellfish in Virginia alone each with a brand name but no coordination in production or marketing. Individual entrepreneurs number in the thousands if one includes tongers and small planters. Furthermore, few of these


small units have any control over seed production or marketing of their products. State and Federal governments have increased their efforts and sub- sidies to help stimulate production