STORAGE OF CAROTENOIDS AND OF VITAMINS A 497 



These species contained little xanthophyll, but did contain carotene, which 

 was converted to the xanthophyll by the Fundulus. A xanthophyll re- 

 sembling taraxanthin was reported, by Wald,^" ^^ combined pigment-epi- 

 thelia and in the choroid layers of the eyes of the red-brown sea robin or 

 gurnard {Prionotus carlinus), the black sea-bass {Centropristis striatus), 

 and the scup or goby {Stenotomus chrysops). L6nnberg402,524 ^Iso noted 

 tlie presence of the taraxanthin-liko pigment and lutein in a number of 

 species of marine fishes. Fontaine and BusneP^s reported the occurrence 

 of carotenoids in the skin of eels. Lonnberg^26,527 observed that, of a large 

 number of species examined, the eyes of only two were devoid of carote- 

 noids, i.e., a cod {Gadus esmarkii) and the Atlantic spiny dogfish {Squalus 

 acanthius) . 



(S-Carotene is an almost universal constituent of the ovaries and ova of a 

 wide variety of fishes. Euler et al.^^^ reported that ^-carotene is present in 

 the roe of many species of fish. Although it is a minor constituent in the 

 egg, it has seldom been observed in other organs of the fishes. ^^^'^^^ In ad- 

 dition to (S-carotene, unesterified xanthophylls are usually found in the ova 

 and ovaries. The complete absence of the carotenoids from the milt of 

 two fishes, the sand-eel or sand lance {Ammodytes tohianus),^^^'^^^ and the 

 herring {Clupea harengus),^^^-^'^^ is in strong contrast to their relative abun- 

 dance in eggs. 



According to Sumner and Fox,^^^ carotenoids may play a role in the pho- 

 toresponses of some fishes. Wald^^^ does not consider the presence of 

 carotenoids in the retinae to be of overwhelming significance, since they are 

 widely distributed in other tissues as well. It is possible that they in- 

 crease visual acuity by reducing chromatic aberration and glare."** The 

 mobilization of the carotenoids in the gonads indicates that they may exert 

 some specific function, but its nature has not as yet been established. 

 Free xanthophylls have been noted in the ova of Ammodytes tobianus,^"^^ 

 but not in those of Salmo solar, which contained only free astaxanthin."^ 

 In the case of Fundulus parvipinnis,^"^^ free xanthophylls are transferred 



"■' G. Wald, /. Gen. Physiol., 20, 45-56 (1936). 



"4 E. Lonnberg, Arkiv Zool, B 33, No. 1, 1-7 (1941-1942). 



"* M. Fontaine and R. G. Busnel, Compt. rend., 204, 1591-1593 (1937). 



626 E. Lonnberg, Arkiv Zool., A 28, No. 4, 1-14 (1935-1936). 



527 E. Lonnberg, Arkiv Zool., A 31, No. 1, 1-14 (1939). 



628 -p. W. Goodwin, 1949; unpul)lished experiments cited by T. W. Goodwin, The 

 Comparative Biochemistry of the Carotenoids, Chem. Publ. Co., New York, 1954. 



6" G. N. Festenstein, 1951; unpublished experiments cited by T. W. Goodwin, The 

 Comparative Biochemistry of the Carotenoids, Chem. Publ. Co., New York, 1954. 



5^ G. L. Walls and H. D. Judd, Brit. J. Ophthalmol, 17, 641-675, 705-725 (1933). 



"1 M. Glover, R. A. Morton, and G. D. Rosen, Biochem. J., 50, 425-429 (1952). 



