Toxicity and Histopathological Effect ofCypermethrin on Juveniles ofClarias gariepinus

摘要

Aim: To study the toxicity and histopathological effects of Cypermethrin on the gill and liver tissues of the Clarias gariepinus. Place of the Study: It was carried out at the toxicology section of the of Water Resources, Aquaculture and Fisheries Technology Department, School of Agriculture and Agricultural Technology of the Federal university, Minna, Niger State, Nigeria.Methodology: The fish were exposed to six (6) acute concentrations (0.025mg/l, 0.050mg/l, 0.075mg/l, 0.100mg/l, 0.125mg/l and 0.000mg/l) for 96 hours. The histopathology of the gills and liver were determined and the LC_(50 )was determined.Results: The 96 hours LC_(50) of the toxicant to the test fish was 0.060mg/L. The most common gill changes at all doses of cypermethrin in solution were destruction of gill lamella, epithelial hyperplasia and epithelial hypertrophy. Hepatic lesions in the liver tissues of fish exposed to Cypermethrin in solution were characterized by degeneration of hepatocyte, vascuolization of cell cytoplasm, fatty degeneration and hypertrophy of hepatocytes. Histological comparison of tissues indicated that most damage occurred in the gill rather than in the liver.Conclusion: Juveniles of Clarias gariepinus exposed to various concentration of Cypermethrin showed that this synthetic pyrethroid was highly toxic to the Clarias gariepinus fingerlings with lethal concentration (LC_(50)) of 0.060mg/l. Evidences of toxicity manifested significantly in the damages caused to the gills and liver studied. The severity of these damages to some selected organs in the body of the fish is proportional to the concentration of the pesticides.