Lobster carapace

P. F. Zagalsky, E. E. Eliopoulos, and J. B. Findlay, The lobster carapace carotenoprotein, alpha-crustacyanin. A possible role for tryptophan in the bathchromic spectral shift of protein-bound astaxanthin, J. Biochem. 274 (1991) 79-83. 

UNRAVELLING THE CHEMICAL BASIS OF THE BATHOCHROMIC SHIFT OF THE LOBSTER CARAPACE CAROTENOPROTEIN CRUSTACYANIN... 

Conjugated keto-carotenoids are complexed stoichiometrically with a simple protein in true carotenoproteins. Such carotenoproteins are encountered particularly in external tissues in the carapace of Crustacea and the skin of Echinodermata. The blue crustacyanin from lobster carapace is the best studied carotenoprotein, as described in several reviews [8,81,82], Detailed isolations methods are given [83], Our group has been involved in early studies on crustacyanin [84], asteriarubin [85], alloporin [86] and linckia-cyanin [87]. 

In nature, astaxanthin is usually found either conjugated to proteins (as in the flesh of salmon or in the lobster carapace) or esterified with fatty acids (as in Haematococcus pluvialis microalgae). In contrast, synthetic astaxanthin is produced in the free form. Synthetic, algae-based, and yeast-based (from Xanthophyllomyces dendrorhous) astaxanthins are distinct in their stereoisomeric compositions as well." Synthetic astaxanthin, as well as all three significant natural sources Haematococcus, Xanthophyllomyces, and extracted cmstacean shells), are used widely as feed additives." Human dietary astaxanthin supplements derived from these three natural sources have also been marketed in recent years. " ... 

In museum collections, most invertebrates will be encountered as natural history specimens, which are divided into dry and wet-preserved. Those animals having a shell or tough exoskeleton, like starfish, shelled mollusks, and lobsters, may be dried after death. The tissue may be removed, but it is often left inside the shell or carapace to shrivel and dry. Wet-preserved specimens are usually fixed in a solution of formalin or some other preservative to prevent the tissues from deteriorating quickly after death. After a brief period, the specimen is usually removed from the toxic fixing solution, rinsed, and placed in a storage solution of 70% ethanol (alcohol) mixed with water. 

There are two species of spiny lobsters in North America. The West Coast spiny lobster Panulirus inter-ruptus) occurs on the Pacific coast, and the Caribbean spiny lobster (P. argus) occurs in the Caribbean Sea, off the Horida Coast, and in the Gulf of Mexico. These warm-water species do not have the huge, crushing, and tearing claws of the Homarus typical lobsters, but they have a needle-sharp, spiny carapace, and very long antennae. 

Hayes, D.K. and Armstrong, W.D., 1961. The distribution of mineral in the calcified carapace and claw shell of the American lobster Homarus americanus, evaluated by means of microroentgenograms. Biol. Bull., 121 307- 315. 

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