Effects of heavy metal accumulation on the 96-h LC50 values in tench Tinca tinca L., 1758

The effects of already accumulated heavy metals (Hg, Cd, Pb) in the body of tench on the 96-h LC50 values of the respective heavy metals were studied. The body concentration of mercury, cadmium and lead was 0.011, 0.32 and 1.59 mg/g respectively, and their 96-h LC50 values were 1.0, 6.5 and 300.0, ppm, respectively. The general accumulation order of heavy metals and their respective 96-h LC50 values were Hg < Cd < Pb. It was observed that the fish with lowest body concentration of heavy metal showed the lowest 96-h LC50 value of the respective heavy metal and vice versa. This close relationship showed that the previous body accumulation of heavy metals has a direct effect on the 96-h LC50 values of the respective heavy metals and the susceptibility of fish.