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Mercenaria Mercenaria (Mollusca: Bivalvia): Temperature-Time Relationships For Survival Of Embryos And Larvae, Vs Kennedy, Wh Roosenburg, M Castagna, Ja Mihursky

VIMS Articles

To estimate the effects of entrainment of Mercenaria mercenaria embryos and larvae in the cooling water systems of steam-electric power plants, we used a thermal gradient apparatus. Cleavage stages, trochophore larvae and straight-hinge veliger larvae were subjected to 11 different temperatures for 8 different time periods. There was a direct relationship of mortality with temperature increase and, at higher temperatures , with increase in time exposure. As the clams aged, temperature tolerance increased, with cleavage stages most sensitive to higher temperature and straight-hinge larvae least sensitive. Multiple regression analyses of percentage mortality on temperature and time produced estimating equations that …

A Study Of The Commercial And Recreational Fisheries Of The Eastern Shore Of Virginia, Accomack, And Northampton Counties: History Review And Recommendations For Improvements, V. G. Burrell Jr., M. Castagna, R. K. Dias

Reports

No abstract provided.

Economic Potential Of Clam Operation, Michael Castagna

Reports

The following estimates are based on the premise that the clam operation will be in an area where clam culture techniques will work. This means the seawater available t_o the hatchery is of suitable quality for this operation at least during the period that the clam larvae and juveniles are in that system. The food growing method (Glancy method) has been successfully used from Canada to Florida so should not be a problem.

Spawning And Rearing The Bay Scallop Vims Laboratory Methods, Michael A. Castagna, William P. Duggan, David Garten

Reports

No abstract provided.

The Economic History Of The Fisheries Of The Eastern Shore Of Virginia, John B. Pleasants

Reports

The economic history of the Eastern Shore has been greatly affected by both its natural characteristics and its location. Each has had both good and bad effects, with the very advantages carrying with them serious disadvantages in a bewildering juxtaposition. For instance, the sea and bay provide a boundless resource of commercially desirable species, yet lead to isolation from major markets of the area. The very isolation 0£ the Eastern Shore and its low population density lessens the possibility of pollution, thus preserving the environment on which estuarine animals are dependent. (...)

Rearing The Bay Scallop, Aequipecten Irradians, Michael Castagna, William Duggan

VIMS Articles

Bay scallops, Acquipcctcn irradians, collected from various bays along the Eastern Shore of Virginia and from Bogue Sottnd, North Carolina, were conditoned and spawned in the laboratory, out of their normal spawning period. A thermal stimulus of 21-2100 was used to stimulate spawning, and larvae set in 10-19 days using cultured algae as food. Juvenile scallops were held in plastic trays in the laboratory for one week, then moved to outdoor tanks with flowing, unfiltered seawater. They remained there until they were about 2 mm in width, then moved to plastic screened wooden floats in the field where they reached …

Hard Clam Culture Method Developed At Vims, Michael A. Castagna, Lawrence W. Mason, Fred C. Biggs

Reports

No abstract provided.

Larval Development Of The Coquina Clam, Donax Variabilis Say, With A Discussion Of The Structure Of The Larval Hinge On The Tellinacea, Paul Chanley

VIMS Articles

Adult specimens of Donax variabilis were spawned in the laboratory and the larvae reared to metamorphosis. Larval length increases from 70 p. to 340 p. during pelagic stages. Height is originally 10 p. to 15 μ. less than length. Height increases less rapidly than length and may be 50 μ. less than length at metamorphosis. Depth is originally 50 μ. less than length. It also increases more slowly than length and may be 150 p. to 170 μ. less than length at metamorphosis. Length of the hinge line is 50 μ. to 60 p.. Round umbos form when larvae are …

Larval Development Of The Pelecypod Lyonsia Hyalina, P. Chanley, M. Castagna

VIMS Articles

Lyonsia hyalina (Conrad) is a small ( 1/2 to 3/4 inch) odd shaped clarn (Fig·. I) common along the Atlantic Coast from Nova Scotia to South Carolina (Abbott, 1954). It is usually found in sand in shallow water with a coating of small sand grains attached to the periostracurn. (...)

Studies On Oyster Scavengers And Their Relation To The Fungus Dermocystidium Marinum, Hinton Dickson Hoese

VIMS Articles

Dermocystidium marinum, a parasitic fungus of oysters, was demonstrated from the stomach of the snail, Urosalpinx cinerea, from the stomach, intestine, and body of three fishes, Gobiosoma bosci, Chasmodes bosquianus, and Opsanus tau, and from the body, especially setae, of two crabs, Neopanope texana and Rhithropanopeus harrisii. All animals containing D. marinum had scavenged oysters infected by the fungus. A few oysters became lightly infected when kept in aquaria with fishes that ·had been fed infected oyster tissue. In one tidal inlet of Chesapeake Bay, Virginia, Eurypanopeus depressus was the most abundant scavenger, followed by Nassarius vibex, Gobiosoma bosci, and …

Drill Control Studies With Formulations Of Polystream And Sevin For 1963, Dexter S. Haven, Michael Castagna, Et Al

Reports

During 1963 , the Virginia Institute of Marine Science conducted a series of tests on oyster drill control with formulations of "Polystream", a chlorinated hydrocarbon and "Sevin", an insecticide .

The utility of these two compounds had previously been investigated by the U. S. Fish and Wildlife Service in Long Is land Sound, in the laboratory and in field trials on commercial beds. Several of these earlier fie ld studies indicated that the treatment prescribed was effective in drill control. Consequently, application was made to the U. S. Department of Agriculture for an " experimental permit." The permit was granted …

Evidence Of A Naturally Occurring Inhibitor Possibly Limiting Dermocystidium Marinum In Virginia, H. Dickson Hoese

Reports

Dermocystidium marinum, a fungus parasite common in oysters on the eastern shore of Chesapeake Bay, suddenly dissapeared at the beginning of the marsh and bay system of' the outer Virginia coast. No D. marinum was found on the outer coast (Seaside) although temperatures and salinities seem to be optimal. Introduction of populations of infected oysters seem to lose the dieease, but individuals do not. What seems to be a water derived inhibitor was found in a few water samples collected at Wachapreague on the Seaside. Comparable inhibition was not found in Chesapeake Bay water. The inhibitor is difficult to demonstrate …

Winter Mortalities Of Oysters On The Eastern Shore Of Virginia, 1959-1961, H. Dickson Hoese

Reports

During the winter of 1960-61 exceptional mortalities occurred among certain oysters on the Virginia Seaside. These mortalities were greatest among James River oysters held intertidally and South Carolina imports placed below low tide level. Intertidal native oysters suffered small mortalities but among subtidal native or James River oysters only the very oldest, with extensive disease histories, showed any winter mortality. (...)

Studies On The Mud Crabs (Xanthidae) Of The Eastern Shore Of Virginia, H. Dickson Hoese

Reports

Small xanthid crabs are among the most abundant members of estuarine communities, and doubtless they have important influence in several communities. In Chesapeake Bay and environs mud crabs are one of the most conspicious members of the oyster community, and they must comprise a large biomass, despite their small size.

Collections and observations were made at 11 localities visited at least once a month on the Eastern Shore of Virginia from August 1959 through November 1960, with some scattered study until August 1961.

Studies On Oyster Scavengers And Their Relation To The Fungus Disease Dermocystidium Marinum, H. Dickson Hoese

Reports

Within the past decade there have been several studies on the biological structure of oyster reefs. These studies, however, gave few insights into the dynamics of oyster communities. The extensive studies of Hedgpeth (1953) , Gunter (1955), and Parker (1955, 1969) in Texas and Korringa (1951) in Holland were largely concerned with sessile forms, and the highly motile fishes went almost unnoticed. While these studies clearly emphasized imrmotile organisms, the present study leans in the opposite direction.

This study started from casual observations of oyster fishes, and progressed to comparisons of mortality of oysters with activity of other members in …

Preliminary Observations On The Fauna And Flora Of Eastern Shore Oyster Beds, 1960, Sewell H. Hopkins

Reports

During the period June 20 -- August 18, 1960, the writer was engaged in survey of the ecological makeup of oyster communities on both the bay side and the sea side of the two Eastern Shore counties of Virginia. Most field studies were made during the regular trips to check mortality in oyster trays at 3 sea side and 6 bay side stations. Some collections were also made during trips to examine planter's beds, or on special collecting trips. Records of previous collections by Mr. H. D. Hoese are also included. Most of the material collected during the current summer …