Aminotransferase activity in the liver and white muscle of Mugil capito fed diets containing different levels of protein and carbohydrate.

Four groups of Mugil capito were fed diets with protein and carbohydrate contents changing reciprocally for 121 days. Food consumption changed proportionally to the carbohydrate content of the diet, while final fish growth was similar for all groups of fish. Liver transaminase levels changed significantly with the protein content of the diet. The changes in body transaminase levels were lower in magnitude. The results obtained are compared to those obtained from other fish species and possible reasons for the differences observed are discussed.