The effects of exposure to multiple stressors of Lead (Pb) and Cypermethrin on biochemical profiles of African catfish, Clarias gariepinus

Abstract

The African catfish (Clarias gariepinus) is a widely cultured fish species in many African countries because of its rich nutritional quality. In this study, the impacts of exposure to common environmental contaminants; a heavy metal (Lead) and a pyrethroid insecticide (Cypermethrin) on the biochemical contents of C. gariepinus was investigated. Juveniles of C. gariepinus were exposed to borehole water (control), 2 mg/L Pb, 0.5 μg/L cypermethrin or 2 mg/L Pb + 0.5 μg/L cypermethrin for 96 h after which the total protein levels, glycogen contents and total cholesterol in the liver and muscle were determined. Fish exposure to cypermethrin and a mixture of cypermethrin and Pb resulted in a significant decrease in glycogen and protein levels but a significant increase in the cholesterol levels in liver and muscle (p < 0.05). There was no significant difference between the control and the group exposed to 2 mg/L Pb. The glycogen and total cholesterol levels were significantly higher in the liver in groups exposed to cypermethrin and the mixture of cypermethrin and Pb (p < 0.05) while the total protein levels were higher in the muscle, although this difference was not statistically significant. The results of this study suggest that environmental pollution of aquatic environments have adverse effects on the health of resident fish as well as other aquatic life.

Keywords: Environmental contamination; African catfish, Clarias gariepinus; glycogen content; total protein; cholesterol level.