Effects of cypermethrin on some biochemical parameters and its amelioration through dietary supplementation of ascorbic acid in freshwater catfish Heteropneustes fossilis.

Static bioassays were made to evaluate efficiency of dietary supplementation of ascorbic acid to counter stress exerted by the pyrethroid pesticide, cypermethrin on freshwater catfish Heteropneustes fossilis. Three levels, a control and two sub-lethal concentrations (0.3 and 0.5 microg L(-1)) of cypermethrin were tested. Stress on H. fossilis was evident from the rise of plasma glucose level and reduction in the level of liver glycogen after 4 h of cypermethrin treatment. Acid and alkaline phosphatase activities of liver and ascorbic acid level of blood, liver and kidney also decreased significantly in H. fossilis exposed to cypermethrin as compared with control. Fish previously fed for 60 d with a diet supplemented by high level of ascorbic acid (1.0 g kg(-1)) could significantly reverse these effects. Fish fed a low level of dietary ascorbic acid (0.5 g kg(-1)) failed to counter the stress of cypermethrin.