Toxicological Studies On Fish

The present work was designed to investigate the hazard of some chemical pollutants on fish. The following points were investigated:1. The toxicity of the two conventional pesticides viz., the organophosphorus insecticide diazinon and the thiocarbamate herbicide thiobencarb as well as the bioinsecticide Bacillus thuringiensis kurstaki against two fish species, Oreochromis niloticus Linn. and Oreochromis aureus Stein., with special reference to:a. The effect of sublethal concentrations of the pesticides tested on some biochemical aspects (e.g., total protein, glucose, createnine, uric acid, transaminases and AchE.b. Histopathological lesions in fish tissues exposed to pesticide-contaminated water.2. Determination of levels and pathways of some heavy metals in the aquatic system.3. Contamination of fish and ambient water with some sex hormones.It was found that the three pesticides caused deleterious effect on the two fish species. Pesticide-exposed fish individuals suffered from disturbances in the physiological and histopathological changes of different organs.Heavy metals were detected in water and fish individuals obtained from different sites contaminated with these pollutants.It was found that fish and the ambient water obtained from different streams were contaminated with the two sex hormones progesterone and testosterone. The visceral fat tissue contained higher amounts of both hormones compared with the muscles tissues.