Assessment of Acute Toxicity of Pesticides Mixtures for Cyprinus carpio and Ctenopharyngodon idella

This study describes the acute toxicity of pesticide mixtures (chlorpyrifos + endosulfan + bifenthrin) to the fish, Cyprinus carpio and Ctenopharyngodon idella. The toxicity of pesticides mixture to Cyprinus carpio and Ctenopharyngodon idella was increased in the following order: Chlorpyrifos + Bifenthrin < Endosulfan + Bifenthrin < Chlorpyrifos + Endosulfan < Chlorpyrifos + Endosulfan + Bifenthrin. However, the difference in toxicity of binary pesticide mixtures for both fish species is rather limited (p<0.05). In all cases (pesticides mixtures) Cyprinus carpio showed more sensitivity than that of Ctenopharyngodon idella. Among four pesticides mixtures, Cyprinus carpio showed significantly more sensitivity towards tertiary pesticides mixture exhibiting the mean 96-h LC50 and lethal concentration of 0.22±0.01 and 0.32±0.02 µgL -1 , respectively. For all treatments, the 96-h LC50 values for Ctenopharyngodon idella ranged from 2.16-7.49 µgL -1 while its lethal concentration values ranged from 3.86 - 13.86 µgL -1 . Comparison of four pesticides mixture revealed that the mixtures which contained endosulfan were more toxic for both fish species.