Impact of heavy metal copper is common pollutants of freshwater ecosystems where they induce adverse effects on the aquatic biota. Freshwater fish, Tilapia mossambicus is an important carp species in Tamil Nadu region having good nutritional values. Fishes living in close association with may accumulate heavy metals. In the present study, the toxic effects of heavy metal copper LC50 1.8 mg/L on alterations in the total lipid content of freshwater fish, Tilapia mossambicus in the different tissues of gill, kidney, liver and muscle were estimated. There is decreased in all tissues on comparison with control. The results indicated the toxic nature of the pesticide dimethoate.
