P.G. Department of Zoology, B.N.Mandal University, Madhepura, Bihar, India
Received : 23rd December, 2019 ; Revised : 22nd February, 2020
Abstract : Cirrhinus mrigala is an Indian major carp commonly preferred in composite fish culture. The common carp Cirrhinus mrigala was exposed to organophosphorous pesticide fenthion to determine the LC50 values at different time interval and its sublethal effects on the hematological and biochemical parameters. LC50 values at varying times were recorded as high as 2.5 mg/l (24hr), 2.2 mg/l (48hr), 1.8mg/l (72hr) and 1.5mg/l (96hr). Fishes exposed to sub lethal concentrations (0.38, 0.19, 0.96 mg/l) for 60 days revealed that the pesticide caused alterations in blood parameters. It is found that it decreases RBC count (6-29%), hemoglobin concentration (7-28%), ESR (11-22%) and clotting time (7-32%), were as WBC count (12-31%) and platelet count (9-43%) were found to be increased. Plasma level of glucose and lactic acid was higher and protein level in blood plasma was lower in exposed fish when compared to control. In conclusion, the changes observed indicate that hematological parameters can be used as an indicator of carbamate related stress in fish on exposure to elevated level.