Toxic effects of endosulfan on haematological and biochemical indices of Clarias gariepinus
The effects of endosulfan pesticide were investigated on juvenile of Clarias gariepinus. Acute test was carried out using 0.04, 0.05, 0.06, 0.07 and 0.08 ppm of endosulfan pesticide with the 96 h LC50 value determined by probit analysis. Chronic bioassays were evaluated on haematological and biochemical indices of the fish for a period of 60 days using four sub lethal concentrations (0.0005, 0.0010, 0.0025 and 0.0050 ppm). Blood sample was collected on days 15, 30, 45 and 60 for haematological and at day 60 only for biochemical analysis. The 96 h LC50 value of endosulfan for C. gareipinus was 0.052 ppm. There was significant reduction (P<0.05) in red blood cell (RBC) at days 15, 30 and 45, haemoglobin (Hb) at days 15 and 45, and packed cell volume (PCV) at all days of the evaluation. White blood cell (WBC) values however showed significant increase (P<0.05) at days 45 and 60. There were variations in mean values of mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC) with significant increase observed only at day 15 of MCHC. Significant reduction in values was obtained for total protein and globulin while significant increase was observed in cholesterol. Results obtained in this study suggest that exposure to low concentrations of endosulfan induced stress and altered the haematological and biochemical indices of treated fish.
Key words: Chronic, acute, biochemical, haematological, endosulfan, cholesterol and glucose, Clarias.