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Full-Text Articles in Life Sciences
Age, Growth Rate, Sexual Dimorphism And Fecundity Of Knobbed Whelk Busycon Carica (Gmelin, 1791) In A Western Mid-Atlantic Lagoon System, Virginia, Micheal Castagna, John H. Kraeuter
Age, Growth Rate, Sexual Dimorphism And Fecundity Of Knobbed Whelk Busycon Carica (Gmelin, 1791) In A Western Mid-Atlantic Lagoon System, Virginia, Micheal Castagna, John H. Kraeuter
VIMS Articles
Growth, onset of sexual maturity, and sexual reversal in laboratory-reared Busycon carica have been examined. Animals first matured at 9 years of age. The first sign of maturity in all animals we reared was the presence of the penis. At 12.4 years of age, one of the animals laid an egg case that did not contain embryos. This animal, and all others, still retained a penis. At 13.5 years, three egg cases were laid and over half the animals had undergone sex reversal (loss of the penis). Field studies have shown that egg strings are laid in the fall on …
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
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 …
Effects Of Perkinsus Marinus Infection In The Eastern Oyster, Crassostrea Virginica: I. Susceptibility Of Native And Msx-Resistant Stocks, Eugene Burreson
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). …