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.