Enzymatic activities in European flat oyster, Ostrea edulis, and Pacific oyster, Crassostrea gigas, hemolymph

Enzymatic activities in the hemolymph of healthy and Bonamia-infected Ostre a edulis and Crassostrea gigas were studied with a commercial kit for the d etection of 19 enzymes: 15 and 16 enzymes, respectively, were detected in t he hemolymph of O. edulis and C. gigas and 10 of them showed relatively hig h activity levels. Most of them existed in both the cell-free fraction of t he hemolymph and in the hemocytes. The cell-free hemolymph fraction of Bona mia ostreae-infected European flat oysters showed an elevated enzymatic act ivity level compared with that of healthy individuals. C. gigas hemocytes p ossessed higher enzymatic activity levels than O. edulis hemocytes. Differe nces in enzymatic activities existed in granulocytes and hyalinocytes in bo th oyster species. The enzyme release from oyster hemocytes seemed to be se lective. The infection by B. ostreae induced enzymatic activity variations in European flat oysters. Higher enzyme levels within hemocytes may contrib ute partly to the natural resistance of C. gigas to the infection by B. ost reae. (C) 2000 Academic Press.