Abstract
The aim of the present study was to evaluate the acute effects of commercial formulation of traiazophos, profenofos, carbofuran and carbaryl in Cirrhinus mrigala fingerlings. Pesticides were applied to fingerlings that had been grown under optimised standard conditions under a maintained static bioassay system. Probit analysis was used for the estimation of LC50 values, which were ascertained as 1.05, 0.21, 0.49 and 4.75 mg/L for triazophos, profenofos, carbofuran and carbaryl, respectively. Cirrhinus mrigala mortality 100% mortality was observed at 1.6 mg/L, at 96 hours of carbofuran exposure of carbofuran. Median lethal concentrations of different insecticides at 24, 48, 72 and 96 h were observed in Cirrhinus mrigala as 1.05, 0.87, 0.75 and 1.05 mg/L, respectively for triazophos; 0.30, 0.25, 0.23 and 0.21 mg/L respectively for profenofos; 1.10, 0.86, 0.66 and 0.49 mg/L respectively for carbofuran and for 6.44, 5.19, 4.77 and 4.75 mg/L, respectively for carbyl. Acute toxic stress was noticed with subjects exhibiting behavioural intoxication, including suffocation, lying on the bottom, erratic swimming, lethargy and downward movements and gulping prior to mortality.