Being that cobia are a top-level predator combing the open ocean for their food, they require a complete feed within the culture system. The majority of the data available on nutritional requirements for cobia is very limited, and is primarily available for juvenile cobia. Current research is still lacking on the diets of fish during the grow-out phase of culture. Cobia are a naturally carnivorous fish that feed directly on other fish and crustaceans on lower trophic levels. This also applies in the culture system where cobia are highly dependent on fish meal in their diets.
For juvenile cobia, it has been determined that dietary protein levels should be 45% dry weight, and lipid levels should be between 5 and 15 % dry weight. Juvenile cobia should be fed at 9% their initial body weight per day. There is limited information available on amino acid and essential fatty acid requirements, and there…show more content… (2009) supplemented fish meal with soy protein, a typical fish meal substitute in fish feed. Finding alternative protein sources in carnivorous fish is very imperative as fish meal is not a sustainable feed source and is one of the most expensive aspects of fish feed. The problem with substituting fish meal with other protein sources, such as soy protein, is major issue with many different cultured species, other than cobia, due to a lack of necessary amino acids and essential fatty acids. As well, palatability issues may occur when using fish meal substitutes. Trushenski (2009) found that fish feed implementing a 100% fish meal diet completely out-performed fish feed a 0% fish meal diet. Fish feed at 100% fish meal diet also out performed fish fed a 50/50 blend of fish meal and soy protein. When fed the 50/50 blend, there was not necessarily a nutritional difference, but intake of the supplemental feed was reduced: the primary reason for the disparity between the two experimental
