STORAGE OF CAROTENOIDS AND OF VITAMINS A 479 



microplanktonic dinoflagellate {Peridinium cindum), and it is probable 

 that the sulcatoxanthin found in the tentacles of the sea-anemones origi- 

 nated in the algae which inhabit them. It was concluded that the astacin- 

 like pigment in Metridium senile was not astacin but a new compound, 

 which was called metridin.-*^^ The white variety contains small amounts 

 of astacin esters; the red anemone has larger amounts of carotenoids, con- 

 sisting of metridin esters, carotene, xanthophyll and xanthophyll esters; 

 the yellow-orange variety contains considerable carotene and xanthophyll, 

 and some xanthophyll esters. The bro^\^l anemone contains only small 

 amounts of carotene, xanthophyll and its esters, and astacene esters. Tet- 

 ronerythrin was found in the verrucose, sessile coral or "sea-fan" (Gorgonia 

 verrucosa) ,'^^'^ and a pigment spectroscopically resembling lutein was noted 

 in the purple-red sea-anemone {Actinia mesetnbrijanthemum).*-^ 



(c) Carotenoids in Echinodermata. a'. Asteroidea: The tissues of this 

 group have bright carotenoid colors, especially the integimient, digestive 

 glands, and eggs."^ The so-called " zooerj^thrine rouge"^^^ or tetron- 

 erythrin identified by Merejkowski*-" in fourteen species of echinoderms is 

 probably identical with astaxanthin.^^^ Euler and Hellstrom^- isolated 

 a blue chromoprotein from the red, "five-finger" starfish {Asterias rubens) 

 which, on h^'droh'sis, gave rise to a carotenoid called asteric acid. This 

 is most probably astaxanthin.-^ A number of other Asteroidea have been 

 shown to contain astaxanthin, including the sun-star {Echinaster seposi- 

 tus),^^ the reddish-violet, short-spined starfish (Solaster endica) ,'^'^^ the 

 reddish-purple, cushion-shaped starfish {Porania pulvillus),^- and the rose- 

 star, a cream and pink starfish (Crossaster (Solaster) papposus).*- The 

 dorsal skin of the last species contains a chromoprotein which, on de- 

 naturation, yields astaxanthin. Fox and Scheer^-^ also identified astaxan- 

 thin in a number of echinoderms found on the Pacific coast, including the 

 paxillate starfish (Astropecten calif ornicus) , the broad-disk star {Patiria 

 miniata), the purple or ochre starfish {Pisaster ochraceus), and the giant 

 star (P. giganteus). In addition to astaxanthin, zeaxanthin or a pigment 

 similar to it was found in all of these species, except Astropecten calif ornicus, 

 which contained pectenoxanthin. Alytiloxanthin was detected in Pisaster 

 ochraceus, and metridin in Pisaster giganteus. In P. ochraceus, 49% of the 

 pigment was in the skin, and -47% in the pyloric cecum, while in P. gigan- 

 teus the values were 7.2% and 22%, respectively. 



*^ C. De Merejkowski, Com.pt. rend., 93, 1029-1032 (1881). 

 «' C. A. MacMunn, Phil. Trans. Roy. Soc. London, 176, 641-663 (1880) 

 «2 H. V. Euler and H. Hellstrom, Z. physiol. Chem., 223, 89-97 (1934). 

 «3 D. L. Fox and B. T. Scheer, Biol. Bull, 80, 441-455 (1941). 



