Abstract
Growth, food conversion efficiency and survival of H. longifilis fed diets with varying levels of protein in which 10% of fish meal was replaced with groundnut cake were studied for 84 days. Fish fed the diet containing 44.17% crude protein showed the best weight gain, specific growth rate, food conversion ratio and efficiency. There was no significant difference (P>0.05) in all the growth parameters and the survival rate of the fish. Addition of fishmeal to fish diets increases feed efficiency and growth although it is a very expensive ingredient. In northern Nigeria 1kg of fishmeal costs about five hundred Naira while its equivalent of
groundnut cake is about one hundred Naira. Cost – effectiveness of diets could be improved by replacing fishmeal with more economical protein sources such as groundnut cake.