Studies of Carotenoid Pigments in Fishes

Abstract

Fishes of this species fed upon a diet rich in xanthophyll (chopped flesh and skin of the garibaldi for 14 weeks) gained about 8% in xanthophyll concn. of their tissues per unit body weight, and more than 22% in absolute amt. On a xanthophyll-free diet (California "halibut") they lost 22% in their xanthophyll concn., though the absolute amount of xanthophyll remained nearly constant. Fishes fed upon a marine worm, known to contain an abundance of carotene, but no xanthophyll, lost about 15% in the xanthophyll concentration, but with their growth taken into account they gained 13.5% in the actual amt. of xanthophyll present. The provisional conclusion is that these fishes in some way converted carotene into one or more carotenoids of the xanthophyll group.