Expression of Heat Stress Biomarkers in Wild and Cultured African Catfish Clarias gariepinus (Burchel, 1822)

Abstract

The expression of heat stress biomarkers in wild and cultured African catfish Clarias gariepinus was investigated in this study. Twenty wild and cultured fish species of average weight of 400±50g were obtained from Owena dam, (Latitude: 7°20'46.04"Longitude: 4°59'54.99") and a reputable fish farm in Akure, Ondo State.  Ten male and female fish from the two source were all conditioned for 3days in concrete tanks. The fish were stocked in concrete tanks of 2m x 2m x 1m with the stocking density of 5 in each tank and the water quality parameters were monitored. Fish were subjected to hyperthermia-induced shock at 39oC with the aid of a 2-kW heating rod (Binatone, Japan). At the end of the hyperthermia-induced stress. Blood samples were collected to determine the glucose level and the expression of Heat Shock Protein (HSP). The highest glucose level of 50mg /l was found in the cultured male African catfish and the lowest glucose level of 18mg/l was found in wild female African catfish. There was higher diversity and expression of HSP in cultured female fish than the wild male. The result of this study showed that the expression of stress biomarkers in African catfish Clarias gariepinus was influenced by the gender and the environment where the fish was found with the male and wild fishes showing more resistance to stress.