Acute toxicity bioassay of the mercury chloride and copper Sulphate in Rutilus caspicus and Rutilus kutum

The purpose of the present study was to determine the acute toxicity (LC50) of HgCl2 and CuSO4 in Caspian roach (Rutilus caspicus) and CuSO4 in Caspian kutum (Rutilus kutum). The Caspian roach LC50 values for HgCl2 at 24, 48, 72, and 96-hrs of exposure, were 0.64, 0.61, 0.42, and 0.28 mg L-1, respectively, and for CuSO4 were 11.55, 5.08, 2.49, and 1.47 mg L-1, respectively. The Caspian roach LC50 values for CuSO4 at 24, 48, 72, and 96-hrs of exposure, were 5.31, 4.17, 3.20, and 2.25 mg L-1, respectively. The results of this study showed that the toxicity of HgCl2 is higher than that of CuSO4 for the studied species. The mortality decreased with time, and most of the deaths were occurred during the first 24 hrs.