UTTAR PRADESH JOURNAL OF ZOOLOGY

The acute toxicity evaluation of cypermethrin, a pyrethroid to common carp i.e. Cyprinus carpio was done with an emphasis on histopathological effects. In this investigation, fish were exposed to different concentrations of Cypermethrin (25% EC) for 21 days. C. carpio were treated with different sublethal concentrations i.e. (5, 10, 15, and 20 percent of 96 hr LC50 value i.e. 2.924 µl/L) of cypermethrin for three different exposure periods, 7, 14, and 21 days. Control and exposed fish were sacrificed at an interval of 7 days and the vital tissues like brain, gills, and kidney were taken to analyze the histopathological alterations. During this experimental period, respiratory stress and erratic swimming activities, disrupted equilibrium, and response were observed which continuously varied with the increasing toxicant concentration. In gills, the proliferation of cells of filament, inflammation, hemorrhage, epithelial cell destruction, fusion of secondary lamellae, and necrosis were noticed. Hence it is concluded that cypermethrin poses a serious threat to aquatic fauna of the ecosystem which can be assessed via histological studies.