PIGMENTS AND COLOURS 



475 



the stores in the hepatopancreas become depleted. During the develop- 

 ment of goose barnacle nauplii (Lepas) there is an interesting colour change 

 from blue to pink, which involves either a rupture of the astaxanthin- 

 protein complex or a change in the linkage. The ovoverdin content of 

 lobster (Homarus) eggs remains unaltered until just before hatching, when 

 the protein complex is disrupted and free red astaxanthin is released 

 (16, 31, 34, 49, 50). 



Tunicates frequently contain bright red, orange and yellow carotenoid 

 pigments, including astaxanthin, various xanthophylls and carotenes. In 



H.C CH 



HO- 



HoC CHq 



CH=CH— C=A=C— CH=CH— 



CH. 



CHq CH- 



H,C 



—OH 



— CH=CH— C=A=C— CH=CH 



-CH 3 I • H 3 C 



CH 3 CH 3 



ASTACENE 



teleosts there are many brightly coloured species having chromatophores 

 charged with carotenoids, and in some varieties these are the dominant 

 kind of coloured cells in the skin. The carotenoids are predominantly 

 xanthophylls, although some ^-carotene occurs in the ovary. Apparently 

 there are only three xanthophyll pigments in this group, namely lutein, 

 taraxanthin and astaxanthin, and a rough division of species can be made 

 on the basis of whether lutein or taraxanthin is accumulated. Astaxanthin 

 occurs with either of the first two pigments. Carotenoids are largely 

 desposited in the skin, although considerable amounts are sometimes 

 present in the muscles, ovaries (especially during sexual activity) and in the 

 liver. Some fishes store large amounts of astaxanthin derived from the 

 consumption of invertebrate animals. Beryx dedactylus, for example, a 

 brightly coloured scarlet and yellow fish, is a veritable storehouse of 

 astaxanthin, which occurs in skin, gills, mouth, mucosa and iris. The sock- 

 eye salmon Oncorhynchus nerka acquires brightly coloured flesh (due to 

 accumulation of astaxanthin) during its sojourn in the sea. The surf-perch 

 Cymatogaster aggregates, feeding upon the red shrimp Hippolyte cali- 

 fomiensis, assimilates xanthophylls but rejects carotenes and acidogenic 

 carotenoids. Part of the xanthophyll is stored in the skin, and some excess 

 accumulates temporarily in the brightly coloured rectum of this species. 



