Effect of Heavy Metal on Biochemical and Hematological Parameters in Cyprinus carpio and its Use as a Bioindicators of Pollution Stress

Abstract

Study was undertaken to evaluate hematological and biochemical changes resulting from the exposure of a common carp Cyprinus carpio to sublethal concentrations (0.05 mg/l) of zinc in water for a period of 10, 20 and 30 days. Four groups of ten fishes were subjected to serial dilutions of the stock solution of zinc of 0 (control), 0.05 mg/l in four large plastic pools of 60 liters capacity by the semi static (renewal) method. At the end of 10, 20 and 30 days exposure period, blood samples were taken from the control and experimental fish. Blood was assayed for selected haematological parameters (haematocrit, haemoglobin, red blood cell counts, white blood cell counts, and total plasma protein and plasma glucose concentration). The derived haematological indices of sublethal concentrations (0.05 mg/l) of zinc caused a dose dependent decrease in haemoglobin values, coupled with a decrease in haematocrit values and red blood cell counts are which indication of anemia of the normal chronic type. The total white blood cell counts and the differential white blood cell counts were decreased except for the lymphocytes in which there was a slight increase. Plasma level of protein and glucose was also lower in the exposed fish as compared to the control. In conclusion, the changes observed indicate that haematological parameters can be used as an indicator of zinc related stress in fish on being exposed to high levels of zinc.