Comparison of the effects of cage rearing of african catfish (Clarias gariepinus) and nile tilapia (Oreochromis nilotica) in cooling water

Abstract

African catfish (Clarias gariepinus) and Nile tilapia (Oreochromis nilotica) of initial body weight 75 g and 60 g respectively, were reared for 58 days in cages placed in cooling water in densities of 100 ind. per cage (1m³ of water). Fish were fed with pellets containing 44.5% of protein and 15.5 % of fat, in rates equal to 1.5% and 2.5% of individual metabolic mass. The results show that at higher feeding rate (metabolic daily ration 2.5%), higher growth rate and lower food conversion ratio were obtained for African catfish. At lower feeding rate (metabolic daily ration 1.5%) no significant differences between the species were observed, neither in growth rate, nor in food conversion ratio.