Changes in nutritional parameters in diploid and triploid African catfish Clarias gariepinus following chlorpyrifos exposure

Abstract

There is a paucity of information about the influence of ploidy status on physiological parameters in organisms following contaminant stress. Also, little is known about the changes in nutritional values of fishes in response to the exposure to contaminants. Full-sibling juvenile Clarias gariepinus were exposed to 3 levels (mean measured 8.9, 17.5, or 28.0 µg l-1) of chlorpyrifos for 21 d. The levels of 3 fatty acids (FAs) in the muscle were significantly different between unexposed diploid and triploid fish. In the chlorpyrifos-exposed fish, the levels of most amino acids (AAs), some FAs, protein, and moisture content were affected in the muscle of diploids, while the levels of some FAs and ash content were changed in the muscle of triploid fish. This work represents the first study of changes in FAs and proximate composition in triploid animals in response to environmental stressors. Fewer changes of nutritional values in triploid C. gariepinus under chlorpyrifos exposure may indicate higher adaptability of triploids than diploids towards environmental stressors. Significant changes in the muscle protein content and AA and FA compositions in diploid Clarias gariepinus in response to chlorpyrifos exposure suggest their application as sensitive indicators of aquatic environmental pollution.