CHAPTER ONE1.0 INTRODUCTION 1.1 BACKGROUND OF THE STUDYThe African catfish Clarias gariepinus is a major warm water species in Africa (Ghana, Ethiopia, Egypt, Mali and Nigeria) and Asia (Malaysia, the Philippines and Thailand) and has been introduced recently in Europe (the Netherland, Germany and Belgium) Latin America (Brazil) (Food and Agriculture Organization, FAO, 1997; Ali, 2001). The superior performance of C. gariepinus compared with other Clarias species in terms of growth rate has probably contributed to the fact that C. gariepinus has been widely introduced to areas outside its natural range (Verreth et al., 1993). Fish culture has rapidly intensified in the last few decades, at an average rate of 8-10% per year (Tacon et al., 2011). To sustain this growth in aquaculture, an associated problem is the supply of ingredients to formulate aquatic feeds, and in particular dietary replacements for fishmeal.African catfish is a suitable alternative to tilapia for subsistence fish farming in Africa and using low-grade feed composed of local agricultural by-products, the yield of catfish from ponds could be as much as 2.5 times higher than those of tilapia (Hogendoorn, 1983). A variety of species of genus Clarias and their hybrids were cultured for reasons of their high growth rate; disease resistance and ability to adapt to high density culture; excellent adaptation to high ambient climate and very efficient feed conversion ratio; ability to mature and remain grand throughout this year in captivity; acceptance of relatively cheap feeds; high fecundity potential for all-year round maturation and induction of final oocyte and high consumers’ acceptance (Viveen et al.,1985).