ABSTRACT Chronic toxicity assays using arsenic trioxide were performed on grass carp, Ctenopharyngodon idellus, to evaluate their impact on protein content, cholesterol and enzymes like ACP, ALP, GOT and GPT. The total protein showed a continuous decline from 15 th day (13.16 mg/ml) to 60 th day (12.32 mg/ml) of exposure whereas there was no significant change in the cholesterol content and weight of the fish. Significant decrease in the activities of ACP, ALP, GOT and GPT were recorded with increase in the exposure period. The total protein and enzymes recovered in 60 days of recovery period
