ADEWOLE Henry Adefisayo, AKINKUOLIE Samuel Olusayo, OLOLADE Promise Olabode, LAWAL Bola Morufat and OLALEYE Victor Folorunso
The impact of municipal sewage effluent on the growth characteristics and hematological indices of an African catfish (Clarias gariepinus) was studied for 90 days with a view to determining potential toxicity of the risk of indiscriminate discharge of municipal sewage on the aquatic biota in a design of four exposure concentrations (0, 1.03, 2.06, 4.12 and 8.24%). The result of the study on the growth performance indices showed a predominant decrease in survival, mean weight gain (MWG), daily weight gain (DWG), and body weight gain (BWG) and a converse marginal decrease in other parameters with an increase in sewage concentration. However, hematological indices analyses showed a decrease (p>0.05) in red blood cell (RBC) count with the increased concentration of sewage effluent. Significantly higher (p<0.05) levels of white blood cell (WBC), Mean Corpuscular Haemoglobin Concentration (MCHC) and Platelet (PLT) were observed in exposed fish compared to the control group. The study concluded that an increase in sewage has an adverse effect on the growth and haematology of the fish.