Assessment of acute toxicity of λ-cyhalothrin to a freshwater catfish, Clarias batrachus

Acute static bioassays were conducted for 96 h period with lambda-cyhalothrin to determine its acute toxicity to a freshwater catfish, Clarias batrachus. The 96 h LC50 value was estimated to be 5.00 mu g l(-1) (95% confidence limit: 4.114-5.712). The alterations in behavioral pattern, such as change in the color of skin, hyperactivity, loss of balance, rapid swimming, increased surfacing activity, enhanced rate of opercular activity, as well as prominent rates of convulsions in treated fish were observed with the increasing concentrations of insecticide as compared to the control fish. The results indicate that lambda-cyhalothrin is highly effective even at very low concentrations.