1. The deficiency symptoms and requirement for vitamin A of young carp have been studied, using the synthetic vitamin A acetate and the basal diet devised by HALVER et al.
2. The deficiency symptoms were characterized by anorexia, retarded growth, faded body color, hemorrhage in the fins and skin, warped gill opercula, and exophthalmia. These symptoms could not be alleviated by administration of vitamin A, except anorexia, retarded growth, and faded body color.
3. Under the experimental conditions adopted, the requirement of young carp was estimated to be 400 ?? 2, 000 I.U. per 100g of diet, or 100 ?? 500 I.U. per kg of body weight per day, on the basis of the deficiency symptoms and vitamin A concentration of the hepatopancreas.
