Effect of Chlorpyrifos on Histology of Liver, Gills, and Brain of Oreochromis Mossambicus (Peters)

Abstract

Most of the river waters in Kerala are found to have several pollutants such as heavy metals, plasticizers, and pesticides. Chlorpyrifos, commonly known as Dursban is a broad-spectrum organophosphate insecticide widely used in Kerala to control insects in crops, termites and to control mosquito larvae. This pesticide is known to reach the aquatic ecosystem causing several damages to aquatic organisms. Fish being on top of the food chain bioaccumulation of these pesticide residues are of concern. This study was to find the histological changes in the liver, brain, and gills of Orechromis mossambicus, commonly called Tilapia, a common freshwater edible fish, on exposure to chlorpyrifos for 7, 14, and 21 days to evaluate the extent of toxicity. For this fish, Orechromis mossambicus of age one to three were procured from a local fish farm of Pathanamthitta district, Kerala, and were acclimatized in tanks in the laboratory and exposed to chlorpyrifos for 7, 14, and 21 days and histology of brain, liver, and gills were carried. The microphotographs of the sections show severe damage to these tissues as early as 14 days of exposure.