Effects of the insecticides carbofuran and fenvalerate on adenylate parameters in bluegill sunfish (Lepomis macrochirus)

Bluegills (Lepomis macrochirus) were exposed to two sublethal concentrations of carbofuran, a carbamate insecticide, and fenvalerate, a synthetic pyrethroid insecticide, in continuous flow bioassay systems for 30 days. Adenylate parameters (ATP concentration, total adenylates concentration, and adenylate energy charge) were monitored in gill, liver, muscle, and stomach tissues. There were significant decreases in adenylate energy charge of gill and stomach tissue relative to initial values after 10 days of exposure to 30 micrograms/L carbofuran. There was also a significant decline in adenylate energy charge in gills of fish exposed to 0.2 micrograms/L fenvalerate relative to initial values. These values returned to normal by the end of the experiment. The biological significance of these changes is uncertain. Adenylate parameters may not be sufficiently sensitive to reflect sublethal effects of pesticides which affect the nervous system of fishes.