Animal Sciences Commons^™

Genetic Variation In The Timing Of Gonadal Maturation And Spawning Of The Eastern Oyster, Crassostrea Virginica (Gmelin), Bruce J. Barber, Susan E. Ford, Robert N. Wargo

VIMS Articles

The gonadal cycles of four groups of eastern oysters, Crassostrea virginica (Gmelin), including native stocks collected that year and inbred strains (reared in Delaware Bay for 5-6 generations) from both Long Island Sound and Delaware Bay, were compared in Delaware Bay in 1987. Inbred strains resembled their respective native stocks; both Long Island groups initiated gonadal development and spawning about one month earlier and spawned over a shorter duration than both Delaware Bay groups. Analysis of covariance revealed that the effect of time on gonadal development was statistically different (P I 0.05) for all between-location group comparisons, but not for …

Hard Clam Mercenaria Mercenaria, G. Curtis Roegner, Roger L. Mann

VIMS Books and Book Chapters

The hard clam is found along the eastern coast of North America from the Gulf of St. Lawrence to Texas. In Chesapeake Bay, the hard clam is restricted to salinities above approximately 12 ppt. An extensive survey of hard clam resources is overdue.

Statements concerning long term trends in populations are not feasible. Hard clams ·grow to a maximum shell length of about 120 mm. There are few documented cases of diseases in wild hard clam populations. Parasitic infestations are also slight. The life cycle of the hard clam includes a pelagic larval phase and a relatively sedentary benthic juvenile …

Spawning And Recruitment Of Black Drum, Pogonias Cromis, In The Lower Chesapeake Bay, John E. Olney, Louis B. Daniel

Reports

No abstract provided.

Larvae Of Diploprion-Bifasciatum, Belonoperca-Chabanaudi And Grammistes-Sexlineatus (Serranidae, Epinephelinae) With A Comparison Of Known Larvae Of Other Epinephelines, Cc Baldwin, Gd Johnson, Pl Colin

VIMS Articles

Morphology is described for larvae of two species of the epinepheline serranid tribe Diploprionini and one of the tribe Grammistini, and known larvae of other epinephelines are compared. Early stage eggs and development of larvae of Diploprion bifasciatum are described from 144 laboratory-reared specimens, and postflexion larvae of Belonoperca chabanaudi are described from wild-caught specimens. Fourmanoir's (1976) description of postlarval Grammistes sexlineatus is modified and expanded. The second and third dorsal-fin spines of larval D. bifasciatum are remarkably elongate, reaching lengths many times that of the body. These spines are thin and flexible, and each is encased in a sheath …

Effects Of Perkinsus Marinus Infection In The Eastern Oyster, Crassostrea Virginica: I. Susceptibility Of Native And Msx-Resistant Stocks, Eugene Burreson

VIMS Articles

A selective breeding program was implemented to attempt to decrease the disease susceptibility of the eastern oyster, Crassostrea virginica, to Perkinsus marinus. Six oyster strains were spawned and the progeny exposed to Haplosporidium nelsoni (MSX) and P. marinus in the lower Chesapeake Bay. Three strains, a Delaware Bay MSX-resistant strain, a Delaware Bay native strain, and a Mobjack Bay native strain (lower Chesapeake Bay) were exposed for three years (1988-90); three other strains, a separate Delaware Bay MSX-resistant strain, a lower James River native strain (lower Chesapeake Bay) and a susceptible control strain, were exposed for two years (1989-90). …

Temporal Variations In Spawning Behavior Of Sea Scallops, Placopecten Magellanicus (Gmelin, 1791), In The Mid-Atlantic Resource Area, James E. Kirkley, William D. Dupaul

VIMS Articles

Interannual variation in spawning of Placopecten magellanicus (Gmelin) may be important to management agencies concerned with maximizing yield-per-recruit via restrictions on meat counts or temporal restrictions on catch and effort. In this study, temporal patterns in the spawning behavior of sea scallops in the Mid-Atlantic resource area for the period April 1987-April 1991 are analyzed using conventional time-series methods. Biannual spawning was found to be characteristic of sea scallops in the Mid-Atlantic resource area but was also found to be erratic in the timing, duration, and magnitude. The spring spawning event was the more predictable and dominant spawning event. The …

The Decline Of The Virginia Oyster Fishery In Chesapeake Bay Considerations For Introduction Of A Non-Endemic Species, Crassostrea Gigas (Thunberg, 1793), Roger L. Mann, Eugene M. Burreson, Patrick K. Baker

VIMS Articles

The Chesapeake Bay oyster fishery for Crassostrea virginica (Gmelin) is in a state of continuing decline. Two diseases, Haplosporidium nelsoni and Perkinsus marinus have effectively eliminated oysters from many sections of the Bay. Despite over 30 years of disease activity the native oysters have developed neither tolerance nor absolute resistance to these diseases, and do not exhibit any recovery in disease endemic areas in Virginia. Repletion programs have completely failed to recover to permanent production areas lost to disease. Present fishery management activities are limited to a controlled retreat away from the disease in an arena where disease distribution is …

Sterile Triploid Crassostrea Virginica (Gmelin, 1791) Grow Faster Than Diploids But Are Equally Susceptible To Perkinsus Marinus, Bruce J. Barber, Roger L. Mann

VIMS Articles

Growth, tolerance of Perkinsus marinus, and gametogenesis of diploid and triploid Eastern oysters, Crassostrea virginica (Gmelin, 1791) were compared in the York River, Virginia between June 1989 and November 1990. Triploid oysters had significantly greater mean shell height (P ,a;; 0.02) and whole weight (P ,a;; 0.005) than diploid oysters throughout the study period. In November 1990, triploids had significantly greater mean dry tissue weight (P ,a;; 0.006) than diploids. On average, triploid oysters reached commercial size (63.5 mm) 5 months before diploid oysters. Diploid and triploid groups became similarly infected with P. marinus during summer 1990. Prevalences reached 96% …

Effect Of Neutral Red Stain On Settlement Ability Of Oyster Pediveligers, Crassostrea Virginica, Patrick Baker

VIMS Articles

The effect of neutral red stain on the settlement of oyster Crassostrea virginica (Gmelin) pediveligers was examined. Larvae were offered two types of substrate: oyster shell and acetate sheets. Settlement was measured as the proportion of pediveligers settled after 24 hours and analyzed with two-factor ANOV A. Staining did not significantly affect settlement, although settlement onto acetate was much lower than onto oyster shell.

Effects Of Perkinsus Marinus Infection In The Eastern Oyster, Crassostrea Virginica: Ii. Disease Development And Impact On Growth Rate At Different Salinities, Kennedy T. Paynter, Eugene M. Burreson

VIMS Articles

In order to assess the impact of Perkinsus marinus infection on oyster growth and mortality, oysters were raised in floating rafts at six sites around Chesapeake Bay. The sites were comprised of two low salinity sites (8-10%0), two moderate salinity (12-15%0) sites and two high salinity sites (16-20%0). Oyster growth was monitored biweekly along with various water qualities including temperature and salinity. Condition index was measured monthly and disease diagnosis was perfonned bimonthly. Oyster growth was initially greatest at the high salinity sites but was subsequently retarded by Perkinsus infection at both the moderate and high salinity sites (where the …

Food And Feeding Of Northern Bluefin Tuna (Thunnus Thynnus) And Yellowfin Tuna (Thunnus Albarcares): A Comparative Study Of The Food And Feeding Habits Of The Northern Bluefin Tuna Off The Coast Of Virginia, Charles Gilbert Barr

Dissertations, Theses, and Masters Projects

No abstract provided.

Susceptibility Of Diploid And Triploid Pacific Oysters, Crassostrea Gigas (Thunberg, 1793) And Eastern Oysters, Crassostrea Virginica (Gmelin, 1791), To Perkinsus Marinus, Judith A. Meyers, Eugene M. Burreson, Bruce J. Barber, Roger L. Mann

VIMS Articles

The susceptibility of Pacific oysters, Crassostrea gigas, to the oyster parasite Perkinsus marinus was compared with that of eastern oysters, Crassostrea virginica, in two separate experiments. Experiments were conducted in flow-through seawater systems with quarantined effluent. Oysters were challenged by addition of infective P. marinus. In the first experiment, which used only diploid oysters, 40% of C. gigas became infected with P. marinus after 83 days compared to 100% of C. virginica. In the second experiment, which examined susceptibility of diploid and triploid individuals of both species, prevalence was high in all groups after 60 days. In …

Status Of The Virginia Public Oyster Fishery - Fall 1991, Bruce Barber

Reports

This report summarizes data collected during 1991 in the Virginia portion of the Chesapeake Bay. The report focuses on the fall oyster survey in Virginia.

Comparative Ecology, Morphology, And Population Genetics Of Black Triggerfish, Melichthys Niger, Kathryn D. Kavanagh

Dissertations, Theses, and Masters Projects

No abstract provided.

A Mark-Recapture Study Of Striped Bass In The James And Rappahannock Rivers, Virginia Annual Report 1990-1991, Joseph G. Loesch, Bruce W. Hill, Philip W. Sadler

Reports

A total of 1,903 striped bass were tagged in fall 1990 and 2,708 in spring 1991 on the Rappahannock River. A total of 2,405 striped bass were tagged in fall 1991 on the James River. In fall 1990, 47.2% of the striped bass tagged on the Rappahannock were less than 425 mm fork length (FL). In comparison, only 13.9% of the fish were less than 425 mm FL in spring 1991. Pound nets in the Rappahannock River accounted for 66.3% of the recaptures, while out of state recaptures accounted for only 2.65% of the total returns. In the fall 1990, …

Striped Bass Research, Virginia: Characterization Of Virginia's Striped Bass Commercial Fisheries Annual Report 1991, Virginia Institute Of Marine Science

Reports

The research reported herein (and in the 1982 through 1989 annual reports) is directly related to Priority III stated in the "Action Plan" (p. 15) of the Emergency Striped Bass Study (Anadromous Fish Conservation Act Amendment, Public Law 96-118). The amendment was the result of a decline in striped bass (Marone saxatilis) landings from Maine to North Carolina since the mid-1970' s. This report summarizes the results of the spring 1991 sampling period and compares the catchability of a multi-sized mesh anchor gill net with that of a pound net.