EVALUATION OF OPTIMUM DIETARY REQUIREMENT OF VITAMIN-C FOR THE GROWTH OF OREOCHROMIS-SPILURUS FINGERLINGS IN WATER FROM THE RED-SEA

The optimum dietary requirements of vitamin C were evaluated for fingerlings of O. spiturus reared in water (40 ppt salinity) pumped from the Red Sea. Different concentrations of vitamin C (0-500 mg of vit. C/kg of diet) were incorporated in a formulated diet. Optimum growth was obtained in diets with a concentration of vitamin C between 100 and 200 mg/kg. Symptoms of vitamin C deficiency were observed in the fish kept on diets containing less than 75 mg/kg. However, no spinal deformities were observed. The vitamin C contents of tissues increased significantly with increasing dietary vitamin C up to 400 mg/kg. Vertebral collagen was 31.8% less in control fish than in fish fed 150 mg or more of vitamin C/kg diet.