Histological and Hepatic Enzymes Response of Oreochromis niloticus and Clarias anguillaris to Pollution in Asa River, Ilorin

Fish can be considered as a good organism for bio-indicator in aquatic habitats as they accumulate contaminant from the water bodies through food. Aquatic ecosystem pollutants response in fishes can lead to biochemical changes and histological alterations. This present the need in assessing ecological and public health effect of toxicity in Asa river on the selected fish samples that are commercially important in the environment. Two stations of Asa river were selected where water and fish were collected for physicochemical parameters of the water, enzymatic and histological investigations in the laboratory in April, 2019. The heavy metals of the water in Unity area of Asa river was higher than that of the standard limit and Asa reservoir. There was an increase in the ALT, AST and ALP biochemical analysis carried out on Oreochromis niloticus and Clarias anguillaris with reduction in total protein level in Unity station. The histopathology of the gills of both Clarias anguillaris and Oreochromis niloticus found in Unity station of Asa river revealed thinner and loner secondary lamella in degenerating secondary lamella and mildly distorted cartilage with epithelial lining in Clarias anguillaris. Hence, proper management of the river is necessary to restore the ecology and make the water fit for use.