Relative toxicity of endosulfan, its isomers, and formulated products to the freshwater fish Labeo rohita.

The relative toxicity of endosulfan, its isomers, and formulated products to the freshwater fish Labeo rohita was tested. The 96-h LC50 values showed that toxicity decreased in the following order: isomer A, 35% emulsifiable concentrate, technical endosulfan, 4% dust, and isomer B. The principal method of detoxification was by formation of endosulfan ether in the liver, Endosulfant, at both sublethal and lethal doses, enhanced oxygen consumption in L. rohita. Histological studies showed minor changes in the liver only.