Toxicity of the pyrethroid pesticide fenvalerate to freshwater catfish Clarias gariepinus: lethality, biochemical effects and role of dietary ascorbic acid.

Static bioassays were made in the laboratory to determine lethal concentration of the pyrethroid pesticide fenvalerate [(RS)-alpha-cyano-3-phenoxybenzyl (RS)-2-(4-chlorophenyl)-3-methylbutyrate] for the freshwater catfish Clarias gariepinus and effects of sublethal concentrations of the pesticide on some biochemical parameters of the fish. For exposure periods of 24 to 96 h, LC(50) values of fenvalerate ranged from 5.83-4.