COMPARATIVE BIOCHEMICAL-STUDIES OF CAROTENOIDS IN SEA-URCHINS .1.

1. 1. The carotenoids of both regular sea-urchins and irregular sea-urchins were investigated from the comparative biochemical points of view. 2. 2. Twenty-five carotenoids were obtained not only from gonad and viscera but also from test and spine. In test and spine of irregular sea-urchins, higher carotenoid compositon than that of regular sea-urchins was noted. 3. 3. A new possible oxidative metabolic pathway of (6′R)-β,e-carotene to (6′R)-α-echinenone[ = (6′R)-β,e-caroten-4-one] was proposed, is a new carotenoid. 4. 4. β,β-Carotene, β-echinenone and (6′R)-α-echinenone were common major carotenoids throughout the gonads, tests and spines of sea-urchins examined except for Peronella japonica. 5. 5. In P. japonica, (3S,3′S)-astaxanthin was a major carotenoid. © 1990.