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Full-Text Articles in Life Sciences
Epizootiology Of Late Summer And Fall Infections Of Oysters By Haplosporidium Nelsoni, And Comparisons To Annual Life Cycle Of Haplosporidium Costalis, A Typical Haplosporidan, J. D. Andrews
The two haplosporidan parasites that cause diseases of oysters along the middle North Atlantic coast of North America differ in their habitats, in timing of oyster mortalities, and in their adaptations to the host. Haplosporidium nelsoni (MSX) kills oysters throughout the year over a wide range of salinities (about 15 to 30 ppt). It has a long infective period of nearly 6 months. This pathogen rarely completes sporulation in its life cycle in oysters. It is highly pathogenic and exhibits irregular activity suggesting that it is poorly adapted to the host species. In contrast, Haplosporidium costalis (SSO) has a short ...
The James River Public Seed Oyster Area In Virginia (A Review Of 22 Years Of Setting And Population Studies, 1946 To 1967 And Changes Caused By Minchinia Nelsoni (Msx) After 1960), Jay D. Andrews
The seed-oyster area is located in a low-salinity sector of the James River where seasonal riverflows and resulting salinities vary widely. Low spring salinities, usually below 10 °/oo in April or May, eliminate most predators and diseases. Prior to 1960, spatfalls were regular and moderate in intensity each year. High quality seed oysters 2 to 3 inches in size were produced with 1000 to 2000 thick-shelled oysters per bushel for use by private-ground planterH. Following the advent of M. nelsoni (MSX) in Chesapeake Bay in 1959:, setting declined to about one-tenth previous levels and there were spatfall failures in many ...