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Full-Text Articles in Life Sciences
Evidence That Qpx (Quahog Parasite Unknown) Is Not Present In Hatchery-Produced Hard Clam Seed, Susan E. Ford, Roxanna Smolowitz, Lisa M. Ragone Calvo, Rochelle Barber, John N. Kraueter
Evidence That Qpx (Quahog Parasite Unknown) Is Not Present In Hatchery-Produced Hard Clam Seed, Susan E. Ford, Roxanna Smolowitz, Lisa M. Ragone Calvo, Rochelle Barber, John N. Kraueter
VIMS Articles
A protistan parasite known as QPX (Quahog Parasite Unknown) has been recently associated with disease and mortality of adult hard clams, Mercenaria mercenaria, from Canada to Virginia. There is concern that the organism may be transported in hatchery-reared seed. Tissue sections of 2,203 seed clams (<1-20 mm) from 13 different hatcheries in six states, collected from 1995 to 1997 and examined by pathologists in three laboratories, failed to show QPX or QPX-like organisms. Further, QPX was not detected in a total of 756 hatchery-produced clams examined during their first year of field growout. From this, we conclude that hatchery-produced seed clams are an unlikely source of QPX organisms.
Disease Processes Of The Parasite Perkinsus Marinus In Eastern Oyster Crassostrea Virginica: Minimum Dose For Infection Initiation, And Interaction Of Temperature, Salinity And Infective Cell Dose, Fle Chu, Ak Volety
VIMS Articles
Experiments were conducted to: (1) test the response of oysters to different doses of the oyster parasite Perkinsus marinus and to 2 stages, meronts or prezoosporangia; and (2) investigate the synergistic effects of temperature, salinity and infective cell concentration on P. marinus infection in oysters. A dose-dependent response of P. marinus infection was found in oysters inoculated with 0, 10, 10(2), 10(4), and 10(5) meronts or prezoosporangia per oyster and maintained at 22 to 25 degrees C and 14 to 21 ppt for 8 to 12 wk. The minimum dose required to infect oysters was 10(2) meronts or prezoosporangia per …
Trends In Research On Crassostrea Virginica And Its Two Protozoan Parasites Perkinsus Marinus And Haplosporidium Nelsoni, Fu-Lin Chu
VIMS Articles
The protozoan parasites, Perkinsus marinus (Dermo) and Haplosporidium nelsoni (MSX), are two important pathogens which have caused severe mortality in the eastern oyster, Crassostrea virginica, in the United States since 1950. This paper reviews and discusses the recent research on the diseases caused by these two parasites and focuses on: I. the in vivo and in vitro interactions between C. virginica and P. marinus, 2. the physiological and biochemical characterization of the parasite, P. marinus, and 3. the development of DNA probes and polymerase chain reaction (PCR) primers specific for H. nelsoni or P. marinus.