Studies on Acute Toxicity of Beta-cypermethrin to Carassius auratus in Different Factors

It was studied that the toxicity of beta-cypermethrin to Carassius auratus in different factors such as water temperature 、pH and fish size.The results showed that the median lethal dose at 96 h(9 6 h-LC50)values increased as the increasing of water temperatu re,the increasing of pH of the water and the increasing fish size.The toxicity o f beta-cypermethrin was affected by many factors, it should be used scientifica lly and rationally.