Life Sciences Commons^™

Modeling Diseased Oyster Populations. Ii. Triggering Mechanisms For Perkinsus Marinus Epizootics, Eric N. Powell, John M. Klinck, Eileen E. Hofmann

CCPO Publications

Densities of Crassostrea virginica remain high enough to support substantial fisheries throughout the Gulf of Mexico despite high mortality rates produced by the endoparasite Perkinsus marinus. The infrequency of epizootics in these populations suggests that controls exist on the disease intensification process. The progression of epizootics in oyster populations, the factors that trigger epizootics, and the factors that terminate epizootics once started were investigated with a coupled oyster population—P. marinus model.

The time development of a simulated epizootic was triggered by environmental conditions that occurred and disappeared as much as t8 months prior to the onset of mortality in …

Shell Disease In The Gold Lip Pearl Oyster, Pinctada Maxima And The Eastern Oyster, Crassostrea Virginica, Frank O. Perkins

VIMS Articles

A description is provided of the anomalous conchiolin deposits which are formed by Pinctada maxima and which are associated with unusual morta]jties. Comparisons are made with brown ring disease found in Ruditapes philippinarum and juvenile Crassostrea virg inica. In P. maxima, the deposits are not organized into a ring but rather a.re broad-based and result in retraction of the mantle with the deposits lying outside the edge of the mantle. Vibrio sp. have been implicated in causing the di seases of P. max ima and R. philippinarum whereas the etiological agent of the disease in C. virginica is unknown. It …

A Survey Of Disease In The Oyster Crassostrea Virginica (Gmelin, 1791) In Rhode Island Coastal Estuaries, Retno Andamari, Michael A. Rice, Paul P. Yevich

Michael A Rice

The presence of potential pathogens and lesions in American oysters, Crassostrea virginica (Gmelin, 1791), from coastal estuaries in Rhode Island was studied. Oysters were collected by hand or tongs from three stations in the Pawcatuck River, two stations in Narrow River, three stations in Charlestown Pond, and three stations in Green Hill Pond, during July/August 1991, November 1991, March 1992, and May 1992. Oysters were processed for histologic examination and determination of condition index. MSX, Haplosporidium nelsoni (Haskin, Stauber et Mackin, 1966), was detected in four of 480 oysters (0.8%); Sphenophyra sp., 15 of 480 (3.1%); Bucephalus sp. 16of 480 …