Evaluation of the Effects of Exposure to Copper Sulfate on some Eco-physiological Parameters in Silver Carp (Hypophthalmichthys molitrix)

Background: Copper is a trace element vital to life, but the toxic effect of water pollution with it on fish is now exhibited. Fish blood is susceptible to contamination-induced stress and its alternation due to the hematological and immunological parameters can be utilized as toxicity indices of xenobiotics. Methods: In this study, juvenile species of silver carp with average weight of 200gr were kept in laboratory conditions for seven days in a 400l tank. One control group consisted of 21 fish stored in a fiberglass tank. The fish were rendered unconscious immediately with 200ppm clove powder. Blood samples were drawn from tail blood vessels by heparinized syringes and saved without delay in ice. Data analysis was done by t-test and ANOVA using SPSS version 19. Results: The immunological (lymphocyte, neutrophil), hematological (Hb, Ht, RBC, MCH, MCHC, WBC) and biochemical (Glucose, Cortisol) indices of silver carp (Hypophthalmichthys molitrix) were investigated at low (10%LC50) and high (50%LC50) concentrations of CuSO4 for 96h. At both concentrations, Ht, Hb, MCV, RBC, and lymphocyte were significantly (P<0.05, P<0.01) lower than control group whereas MCH, MCHC, WBC, glucose, cortisol, neutrophil were significantly (P<0.05, P<0.01) larger in comparison with the corresponding control group. Conclusion: The main finding of this study is that CuSO4 concentrations (low and high) may cause some alternations in the hematological, biochemical and immunological parameters of the studied fish. Assessment of these indices can supply a useful indicator of CuSO4 of water bodies. It appears that MCHC is an appropriate biomarker of CuSO4 in silver carp (H. molitrix).