CAROTENOID PIGMENTS IN FISH-II

Three groups of each sixty, grey colored but approaching to their discoloration stage, immature goldfish were reared for one month on different diets; rich in carotene and lutein (Group I), free from carotenoid (Group II) and rich in astaxanthin (Group III). The mean amount of carotenoids per individual fish of a group greatly increased in Group I, remained unchanged in II and decreased in III from the initial level, respectively. A few assumptions may be proposed in regard to the cause of negative effect of astaxanthin on goldfish; the goldfish do not accept astaxanthin which is different from their red carotenoid as suggested in the authors' previous paper; the sample fish were too immature to accept astaxanthin regardless of whether or not it may be identical with the red pigment inherent to goldfish; or the fish would always have to convert lutein into the red pigment in the body with no direct route open for the accumulation. Checks on these hypotheses remain to be made in future.