Effects of zinc on accumulation of cadmium in various tissues and organs of Oreochromis niloticus

In this study, effects of zinc on the accumulation of cadmium in kidney, liver, gill, muscle and blood of Oreochromis niloticus were investigated. The fish were exposed to 0.1 mg/L Cd, 0.1 mg/L Cd+0.5 mg/L Zn and 1.0 mg/L Cd, 1.0 mg/L Cd+5.0 mg/L Zn mixtures for 7, 14 and 21 days, cadmium accumulation in tissues were measured by Atomic Absorbtion Spectrophotometry. Cadmium accumulation increased with increasing concentrations of cadmium in the medium and with increasing periods of exposure tissues studied. Highest accumulation occured in the followed by liver, gill and muscle. In all exposure period, accumulation of cadmium in whole tissues of O. niloticus decreased in the presence of zinc. In both mixed exposure concentrations, zinc significantly reduced the accumulation of cadmium in the gill and kidney of O. niloticus. Key Words : Cadmium, Zinc, Fish, Accumulation, Oreochromis niloticus