author(s)
Saravanan N, Uma T and Jothi Narendiran N

abstract
Cypermethrin is one of the synthetic pyrethroids which are most widely used for more than three decades as possible alternative to the organophosphate, organochloride and carbamate pesticides. Its toxic effects may include lethal and sublethal concentrations, which may change the growth rate, development, reproduction, histopathology, biochemistry, physiology and behaviour on target organisms and undesirable perturbations in the environment. In these backgrounds of toxicology aspect the present study focussed for the concentration measurement of Estrodiol (17), Liver and ovarian vitellogenin in the exposed cypermethrin to Esomus danricus in 45days experiment in different concentrations. The adverse effects of the Vitellogenin and Estrodiol-17 were decreased when compared to control to less concentrations of cypermethrin exposure to E. danricus. The findings were significant as the toxic effect of cypermethrin was found to increase with time of exposure suggesting its deleterious effect on aquatic organisms not only directly but also by bio accumulations.