Virginia Institute of Marine Science
Aquatic Living Resources
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 is suggested that the coccoid bodies formed in the mantle of C. virginica, but not in affected P. maxima and R. philippinarum, a.re sequestered portions of cytoplasm formed as a result autophagocytosis. Stimuli which could be responsible for inducing sequestration a.re discussed. The ultrastructure of the presumptive autophagosomes is described and compared to similar bodies found in C. gigas infected with a herpes-like V!ruS.
Pinctada maxima, Crassostrea virginica, shell disease, conchiolin, ultrastructure, light microscopy.
Perkins, Frank O., Shell disease in the gold lip pearl oyster, Pinctada maxima and the Eastern oyster, Crassostrea virginica (1996). Aquatic Living Resources, 9, 159-168.