According to Thomas et al. (2001), the use of low-cost fishmeal replacers in diet formulations is an important factor that can significantly affect the physical qualities of the feed pellets, although the diet meets the nutritional requirements for the target species. Nutritional studies aimed at replacing fishmeal in aquafeeds with more economical and environmentally sustainable alternatives have become increasingly common due to the stagnated global production and high cost of fishmeal. The low cost and wide-availability of oilseed meals, particularly copra and palm kernel meals in many tropical countries where aquaculture is practiced have generated much interest in their potential use in fish diets. The presence of high fibre contents and/or anti-nutritional factors (ANFs) in unrefined forms of these meals, however, limits their inclusion in aquafeeds to very low levels. The selected inclusion level for the oilseed meals in this study for example, is reflective of the possible presence of ANFs and the fact that very high fishmeal replacement on a weight-for-weight basis by these unrefined plant protein sources is not feasible because of