Toxicological Assessment of Chromoleana odorata on Clarias gariepinus Juveniles

Abstract

A study was carried out to investigate the toxicity effects of exposure of aqueous extract of Chromolaena odorata leave on gill/liver (histological) of juveniles catfish Clarias gariepinus. The leaves were harvested fresh, air dried for 7 days under ambient room temperature. 200 healthy juveniles catfish Clarias gariepinus specimen with average initial weight of 12.40 ± 2.46 cm (mean total length) and 8.26 ± 1.25 g (mean body weight) were exposed to aqueous extract of Chromolaena odorata leave at the concentration of 50, 100, 150, 200, 250 mg/l respectively. The physical reactions observed in the fish were: erratic swimming, gasping for air, loss of reflex, hyperactivities and skin discolorations which were more pronounced at high concentration and exposure time. The pH and dissolved oxygen significantly (P < 0.05) decreased as the concentrations of C. odorata leaves extract increased. However, the values of Ammonia in the exposed media significantly (P < 0.05) increased as the concentrations of C. odorata leaves extract increased, compared to the control test medium. A high mortality rate was recorded, the histological conditions on gill and liver includes the deformation of gill tissue with overlapping of secondary lamella and disintegration of epithelial tissue leading to diffuse mass of the gill lamella due to rapid cell lysis, gill clogging and gill structure disruption. Deformed primary and secondary lamella with disintegrated gill filament, increasing vasculation, total fusion of gill filament lamella and filament length variation. Damage became severe with increasing concentration in C. odorata leaves to fish and exposure, while liver of Clarias gariepinus shows liver hepatocellular alteration and increase in hepatocyte disintegration, rupture blood cells in the entire cell with hemorrhage of the vessels and blur nature with severe breakage due to rupture.