Acute Toxicity of Zinc Sulfate Heptahydrate (ZnSO 4 *7H 2 O) and Copper (II) Sulfate Pentahydrate (CuSO 4 *5H 2 O) on Freshwater Fish, Percocypris pingi

摘要

This study was carried out to determine acute toxicity of two heavy metals (zinc and copper) to fingerlings Percocypris pingi by static bioassays. The experimental fish were subjected to a range of concentrations of heavy metals. At different exposure periods (24 h, 48 h, 72 h and 96 h), the mortality rate were separately investigated. The median lethal concentration (LC 50 ) was determined with Probit analysis. The LC 50 values of zinc for the Percocypris pingi at 24 h, 48 h, 72 h and 96 h were 3.504 mg/L, 2.933 mg/L, 2.852 mg/L and 2.852 mg/L, respectively. But the LC 50 values of copper at 24 h, 48 h, 72 h and 96 h were 1.730 mg/L, 1.389 mg/L, 1.340 mg/L and 1.340 mg/L, respectively. The heavy metals were ranked in order of toxicity: copper >zinc. The safe concentration of zinc and copper were 0.2852 mg/L and 0.1340 mg/L, respectively. Physicochemical parameters variables e.g. dissolve oxygen, total hardness, and ammonia nitrogen of aquaria were monitored under different concentrations of zinc (0, 1.60, 2.40, 3.20, 4.00, 4.80, 5.60) mg/L and copper (0, 0.60, 1.00, 1.40, 1.80, 2.20, 2.60) mg/L.