Effect of Agricultural Pesticide, Cypermethrin on Changes in Behavioural and Protein profile of larvivorous fish Aplocheilus lineatus

Abstract

Cypermethrin is a synthetic pesticide that is widely used in agricultural fields and domestic areas to control pests and insect vectors. Cypermethrin considered to be a synthetic pyrethroid is extremely lethal on insects, and fishes and has a low impact on mammals and Aves. The present study aimed to investigate the acute toxicity of cypermethrin on the larvivorous fish Aplocheilus lineatus, which is the most common fish seen in pools, ponds, streams, paddy fields, and similar wetlands. The fish is highly significant in controlling vector-borne diseases prevailing in tropical countries. The LC50 value was determined to be 1.8 µg/L after 96 hrs of exposure to cypermethrin and the lethal value was 4 µg/L. The fish showed various behavioral changes during the experiment, including convulsions, vigorous gasping for air, erratically swimming, and loss of equilibrium. The results showed that even low concentrations of cypermethrin can exert acute effects on the biochemical constituents and behavioral aspects of A. lineatus. Total protein, structural protein, and soluble protein decreased from 1.33 ± 0.003 to 0.746 ± 0.015 mg/g, 0.967 ± 0.024 to 0.476 ± 0.0272 mg/g, and 0.444 ± 0.09 to 0.360 ± 0.018 mg/g, respectively, at 96 hours of exposure to 1 µg/L of cypermethrin. At the same time, glycogen levels also decreased from 1.11 ± 0.054 to 0.51 ± 0.019 mg/g. These variations in the behavioral and biochemical content of the fish after exposure indicate the toxic effect of cypermethrin. Hence the present study suggests monitoring and regulatory use of this pesticide.