O.A Akinrotimi^1,, E.E. Orlu², U.U Gabriel³

A total of 180 Tilapia guineensis (mean length 20.62cm±2.1SD and mean weight 150.28g±3.14SD) were exposed (10 fish per tank) to 0.00mlL^-1 (control) 0.1, 0.2, 0.3, 0.4, 0.5mL^-1 industrial effluents in triplicates in plastic tanks under a static renewal condition for 15 days to determine the effect of the exposure on the haemoglobin (Hb), red blood cells (RBC), packed cell volume (PCV), white blood cell (WBC), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV), differential counts (neutrophils, monocytes, and lymphocytes), thrombocytes and blood glucose. Exposure of T. guineensis to these toxicants, caused a concentration dependent significant (P < 0.05) reduction in the values of Hb, RBC, PCV, MCH, MCHC, lymphocytes and thrombocytes. However, there was a gradual increase in the values of WBC, MCV, neutrophils, monocytes and blood glucose as the concentration of the effluent increased. These alterations were more pronounced in the fish exposed to 0.30, 0.20 and 0.50m/L^-1 of the effluents. Results from this study suggest that brief exposure of T. guinensis to industrial effluents could cause some level of stress as manifested by changes in the haematological parameters of fish under consideration.

haematology, effluents, tilapia, acute toxicity, aquatic population