Abstract

The present study aimed to evaluate the effect of sublethal concentration of a synthetic pyrethroid pesticide,
i.e., deltamethrin (DM) on enzymological responses in an Indian major carp, Labeo rohita. In this study, the LC50
values of DM for 96 h were found to be 0.09 ppb. Effect of sub-lethal dose of delamethrin was evaluated 1/10th of
96 h LC50 value, 0.009 ppb concentration of deltamethrin was evaluated on carbohydrate metabolism of L. rohita.
The significant (p<0.001) decrease in glycogen levels were observed in liver as well as in muscles during the 24 h
of incubation and gradual increase were observed when compared with control group. The increase of lactate
dehydrogenase was progressive in all the tissues, i.e., gills, brain, liver, and kidney and reached highest at 96 h of
exposure in gills. However, the significant decrease in succinate dehydrogenase and malate dehydrogenase was
observed in collected tissues and decrease is less at 24 h and it was increased along the exposure period. These
results suggest that the tested concentrations of DM could have significant adverse effects on the hormonal and
enzymologicalparameters of fish L. rohita. The alterations of these parameters can be effectively used to monitor
the impact of DM in aquatic ecosystem.