Abstract
This study aimed to determine the median lethal concentration (96-h LC50), acute and sublethal effects of malathion, an organophosphorus pesticide on hematological and biochemical responses in an Indian major carp, Labeo rohita. In this study, the LC50 value of malathion for 96 h was found to be 3.4 ppm. During acute (3.4 ppm) and sublethal [1/10th of 96 h LC50 value (0.34 ppm) studies, all the hematological parameters except WBC were significantly decreased (p<0.05). Besides, when compared with the control group, a significant (p<0.05) decrease in biochemical activity was also observed in malathion treated fish during acute and sublethal exposure periods. These results suggest that the tested concentrations of malathion could have significant adverse effects on the hematological and biochemical parameters of fish, Labeo rohita. The changes in the parameters can be effectively used to determine the impact of malathion in the aquatic ecosystem.