The effects of Perkinsus marinus infection on physiological processes in the eastern oyster, Crassostrea virginica

Although Perkinsus marinus infections have been associated with high mortalities in populations of the eastern oyster Crassostrea virginica for several decades, the pathological mechanism(s) by which death is induced is unclear. Physiological changes in the oyster associated with P. marinus infection are not well studied. Infections typically cause significant reductions in growth rare and several studies have shown reductions in condition index as well. The reduction in condition index may be the result of a perturbation in free amino acid metabolism caused by infection. Further, the effects on free amino acid metabolism may be associated with parasite-induced changes in mitochondrial function. A significant acidosis has also been shown to occur in the hemolymph of infected oysters which may affect general tissue functions. However, changes in oxygen consumption and clearance and assimilation rates of whole oysters have not been correlated with increasing infection. Finally, reproductive capacity may be reduced by P. marinus infection.