About 13.5% of the known causes of global warming come from agriculture (PCC 2007) and the contribution of aquaculture production as a result of excess and undigested nutrients is considerable and should be checked. Fish when fed use the nutrients provided for maintenance, growth and production purposes but in addition to the needs of the fish, excess nutrients are eliminated, depleting water quality parameters, increasing production costs, the concentration of ammonia and invariably have ecological consequences. Fish obtain energy from protein and non-protein sources, but the use of protein energy is nutritionally, economically and ecologically wasteful (Manjappa et al 2002). Energy utilization and metabolism from carbohydrate or lipid sources in fish varies depending on the species, age group, composition of the fish's enzyme profile, and the source or origin of the nutrient, and there is a delicate balance between the different nutrients fed to fish in terms of protein/energy ratio and the ability of fish to efficiently utilize nutrients from these sources (Manjappa et al 2002, Peres and Oliva-Tees...