EFFECTS OF A FUNGICIDE ON INVITRO HEMOCYTE VIABILITY, PHAGOCYTOSIS AND ATTACHMENT IN THE AMERICAN OYSTER, CRASSOSTREA-VIRGINICA

The effect of a commercial fungicide containing Triforine as the active ingredient was tested in vitro for its effect on the viability, phagocytic ability and attachment properties of hemocytes from the American oyster, Crassostrea virginica (Gmelin 1791). Cell viability was determined by the hemocytes' ability to hydrolyze fluorescein diacetate to produce intracellular fluorescence. Phagocytosis was evaluated with 2-mum fluorescent beads and cell attachment was determined by counting cells remaining in suspension in hemolymph after gentle centrifugation onto a bead monolayer. Both cell viability and phagocytic activity were reduced to approximately 50% of control levels within a dose range of 0.0295 to 1.966 mug Triforine per ml of hemolymph. Addition of the highest dose failed to further reduce viability or phagocytosis. Cell attachment to bead surfaces was inversely proportional to the dose of fungicide. These data show that exposure of hemocytes to fungicide reduces the cells' ability to function in their normal capacity as immune cells.