Bioaccumulation and Histopathological Alterations in Liver Caused by Endosulfan Toxicity in Oreochromis Niloticus

The toxic effects of sublethal concentrations of endosulfan on Oreochromis niloticus was examined using bioaccumulation and histopathology studies of the liver as toxicological endpoint.   The Organization for Economic Cooperation and Development #407 recommended static renewal bioassay was employed during the test .The test fish were exposed to sub-lethal concentrations separately for a period of 7, 14, 21, and 28 days. At the end of each exposure period the liver tissues were isolated and analyzed using high performance liquid chromatography for bioaccumulation study, while alterations observed in exposed fish were determined in the laboratory by light microscopy using standard technique of Haematoxylin and Eosin staining. No mortalities occurred in any group during the test .The severity of the histological alterations observed in the liver of the treated fish reflects the concentrations of the toxicant, level of depuration and exposure durations .An indication that the regulating mechanisms of the liver has been overwhelmed resulting in the structural damages .The findings showed that the body could be liberated of contaminants after longer exposure period however, the effects on the body’s tissues remain lethal.