ABSTRACT

The study investigated the histo-hematological properties of African Catfish exposed to antifouling paint. Concentrations 0.75ml/L, 1.00ml/L, 1.25ml/L, 1.50ml/L and control which were fractions of a preliminary 96h LC50 and control were used in the static bioassay. Physicochemical parameters (Temperature, pH, DO) of the test media were measured across the concentrations and it was found that Temperature and pH remained the same during the 96hours exposure period while Dissolved Oxygen concentration was depleted with increase in concentration and hours. This induced stress on Clarias gariepinus and resulted in behavioral changes like air gulping, loss of reflex, rapid opercula movements and death at higher concentrations of 1.00ml/L, 1.25ml/L and 1.50ml/L between 72hours to 96hours exposure. The blood parameters PCV and RBC, and differential counts such as neutrophil decreased with increasing concentration of the toxicant and become significantly lower (P < 0.05) at higher concentration when compared with the control. While WBC and Lymphocyte were observed to have increased with increase in concentration of the toxicant. It is believed that observed depression in PCV coupled with decreased and RBC are obvious signs of anemia. Degenerative changes were observed in the organs of C. gariepinus. The gills of fish in the varying concentrations particularly the highest concentrations (1.50ml/L) showed signs of severe necrosis with severe inflammation. The fish in highest concentrations also showed degenerative changes such diffuse lobular hepatocytes necrosis with severe inflammation but no fibrosis.