Inflammatory responses in the Indian edible oyster Crassostrea madrasensis under apparently normal conditions and on exposure to an organophosphorous pesticide (Nuvan) and a heavy metal (copper) werestudied. The inflammation was induced in the adductor muscle by injecting Freund?s complete adjuvant. The animals were exposed to these pollutants for 14 days. Samples were examined histologically at 24 hours, and on the 3rd and 7th day. In the animals that were maintained in apparently normal conditions, initially there was mild to moderate infiltration of hemocytes, which secreted proteinaceous material. At later stages, the hemocytes were found to excrete fibrin like shreds, which were observed radiating from small cells. Finally, these hemocytes (fibrocytes) aggregated into nodules, in which some of the cells assumed a spindle shape and were arranged in concentric layers, forming a mass of cells. In Nuvan and copper
exposed animals, the inflammatory reactions were very much subdued.

Crassostrea madrasensis, copper, Nuvan, hemocytes, inflammation, edible oyster