PANTOTHENIC ACID AND VITAMIN B12 CONTENTS ASSESSED FOR THE RAINBOW TROUT DURING MATURATION

A trout hatchery in Tokyo started feeding the rainbow trout (Salmo irideus) with a formulated diet in June 1961. To study possible relationship between maturity of fish and their vitamin contents, a number of the fish reared in the hatchery were sampled at different stages of maturity, one, four or seven months before spawning (Table 2); microbiological analysis was performed for levels of pantothenic acid and vitamin B12 in various organs of the sample fish (Table 1). The analytical results tabulated in Table 3 indicate no definite relation between the pantothenic acid contents and maturity of the rainbow trout. However, samples in the most advanced stage of maturation show remarkable increases of the vitamin B12 level in various organs except ovary. The fact suggests that vitamin B12 plays a role in maturity of the fish.