Ogundiran Mathew Akinloye*, Fawole Olubanjo Olatunde, Ajala Olumuyiwa Olasunmibo
Gross impact of water pollution and water borne pollutants on aquatic organisms and man has become a great concern to public health in the recent time. Since fish gills are indirect contact with the environmental medium and are very sensitive to changes in water quality while fish liver serves as gate-keeper to the entire body of fish. Therefore, the aim of this study was to evaluate the effects of pollutants from the polluted Asa River on the gills and liver histology of Clarias buthupogon and Heterobranchus longifilis. The sample included a total of 55 individuals (28 for C. buthupogon and 27 for H. longifilis). There was a recorded moderate to intense alterations of gill tissues. The most notable alterations were congestion of blood vessels, desquamation, swelling of pillar cell, hyperplasia and hypertrophy of the gill epithelium. Epithelial lifting of the basement membrane was common in virtually all sampled fish species, while circulatory disturbances were slightly pronounced. The liver showed congestion of central vein, degeneration of hepatocyte, sinusoidal distortion, cellular inflammation and necrosis. However, all histological alterations recorded in the gill and liver tissues were most likely to be caused by increased concentrations of certain pollutants from industrial, domestic and agricultural premises. Furthermore, these results represent an additional reason to proceed with a detailed monitoring of the Asa River and the wildlife therein, for the sake of public health.