RESUMO
Activity of a few biomarkers have been investigated on freshwater fish Channa punctatus treated with monocrotophos for acute exposure to 18.56 ppm at 96 hr and subacute exposure viz. 0.46 ppm, 0.96 ppm and 1.86 ppm for 30 days. Biomarkers such as total protein, lipid peroxidation and acetylcholinesterase have been measured in different tissues of fish viz. gills, liver, brain and muscles. The protein levels were found to be depleted in all the tissues after pesticide exposure to lethal and sublethal concentration over the control, where as the lipid levels showed an increase under the stress of pesticide monocrotophos. The increased lipid level may be due to inhibition of lipase activity and other biomarkers of lipid metabolism. A significant inhibition of brain acetylcholinesterase (AChE) indicating its effects on nervous system have also been observed. These parameters can be used as biomarkers to predict the early toxicity of monocrotophos added to aquatic ecosystem.