The rate of accumulation of Cu2+ was maximum in gills of exposed prawns and no detectable amount of Cu2+ was observed in the gills of control prawns, as well as at the lowest concentration of Cu2+ (0.20 mg L–1). The rate of accumulation increased along with the increasing of Cu2+ concentration, reaching 10 μg .g–1 at 0.80 mg L–1, Table 3. Hepatopancreas: As with the gills, Cu2+ could not be traced in the hepatopancreas of the control fish, as well as at the lowest concentration (.020 mg L–1). Even though the quantity of accumulated Cu2+ was less in the case of hepatopancreas when compared to gills, the pattern of accumulation showed a more or less continuous increasing trend, Table 3. Muscles: The rate of accumulation of Cu2+ in muscle increased along with the exposure to high concentrations. The mean rate of accumulation at 0.80 mg L–1 was 55 μg .g–1, this rate of accumulation was less as compared with other tissues