Biochemical and Oxidative Stress Responses in Clarias gariepinus Exposed to Sublethal Concentrations of Benzo[a]pyrene

The effect of benzo[a]pyrene (BaP) on selected plasma biochemical parameters of the tropical African catfish C. gariepinus was investigated. Apparently healthy juvenile fish (n = 90; mass = 19.7 ± 1.8 g) were exposed to sublethal concentrations of BaP over a period of 35 days after which haematological and plasma biochemical analysis were carried out on whole blood and plasma respectively. While there were significant declines in red blood cell count (RBC), hemoglobin, haematocrit and platelet count, significant elevations were observed in mean cell volume (MCV), mean cell haemoglobin concentration (MCHC) and white blood cell (WBC) count. Significant increases were also observed in the activities of the liver enzymes, alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP). There were significant increases in the activities of the oxidative stress enzymes, catalase (CAT), superoxide dismutase (SOD) and glutathione s-transferase (GST). Findings from this study reveal that benzo[a]pyrene causes changes in haematological and plasma biochemical profiles in exposed aquatic organisms.