Impact of pesticides is common pollutants of freshwater ecosystems where they induce adverse effects on the aquatic biota. Freshwater fish, Cirrhinus mrigala is an important carp species in Tamil Nadu region having good nutritional values. Fishes living in close association with may accumulate pesticides. In the present investigation, the toxic effects of the dimethoate LC50 1.6 mg/L on some biochemical characteristics (total carbohydrate and lipid in the tissues of gill, liver and muscle) of the freshwater carp fish, Cirrhinus mrigala were estimated. There is decreased in all tissues on comparison with control. The results indicated the toxic nature of the pesticide dimethoate.
