Dietary ascorbic acid as a means to counter the stress of cypermethrin on the growth of freshwater catfish Heteropneustes fossilis

摘要

Two months of experiments performed in outdoor vats in a 3 × 3 factorial design to evaluate the effects of three sublethal levels (0.0, 0.3 and 0.5 μg L-1) of cypermethrin on freshwater catfish Heteropneustes fossilis fed with three different levels (0.0, 0.5 and 1.0 g kg-1) of ascorbic acid (AA) in the diet. Even the lower sublethal level (0.3 μg L-1) of cypermethrin produced significant reduction in growth and deposition of protein in the body of H. fossilis. Dietary supplement of AA at 0.5 g kg-1 failed to counter these ill effects of cypermethrin on H. fossilis, but a supplement of 1.0 g kg-1 AA significantly increased the AA reserve in the body of the fish, and the ill effects of cypermethrin on growth were reversed. It was concluded that the catfish H. fossilis required an exogenous supply of AA to counter the stress of cypermethrin.