FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

The aims of this study were to examine the role of Portuguese oyster (Crassostrea angulata) hemocytes in the defense mechanism and to establish hemato-immunological parameters. Following cytochemical staining, the granulocytes and the agranulocytes exhibited a PAS positive reaction for polysaccharides; however, a lipid positive reaction was only observed in the granulocytes. The activities of acid phosphatase, alkaline phosphatase, β-glucuronidase, naphthol AS-D chloroacetate esterase, α-Naphthyl acetate esterase and peroxidase were observed in the granulocytes. In immunological assays, both of the granulocytes and the agranulocytes were able to phagocytose fluorescent latex beads and zymosan particles and produce superoxide anion against foreign agents. Moreover, the granulocytes exhibited greater phagocytic ability and more activity in the uptake of neutral red than agranulocytes. The basophilic granulocytes showed the strongest phagocytotic activity of fluorescent latex beads.