In his travels aboard the HMS Beagle, British naturalist Charles Darwin noted, "Throughout South America, the flamingo appears singularly attached to salt lakes. I saw instances of this throughout Patagonia, in the Cordillera of Northern Chile, and at the Galapagos Islands." Bright pink American Flamingos (Phoenicopterus ruber) and other species of the genus Phoenicopterus live in some of the most inhospitable habitats of the world. Salt lakes are landlocked bodies of water with concentrations of sodium chloride and other mineral salts that often exceed that of the ocean. While such conditions discourage all but a few forms of life, those that have adapted - collectively known as halophiles - make up a large part of the flamingo's diet. In fact, halophilic algae of the genus Dunaliella produce and accumulate large amounts of carotenoids, the organic pigments to which flamingos owe their distinctive pink color.
Related Record from CAplus
1962:445097 Metabolic fractionation, storage, and display of carotenoid pigments by flamingos. Fox, D. L. Comparative Biochemistry and Physiology 1962, 6, 1-40. Captive specimens of Phoenicopterus ruber and P. chilensis gradually lost the red pigmentation of the exposed skin and of the feathers through molting, unless fed a diet rich in carotenoids. The brightly-colored feathers, exposed leg skin, egg yolk, blood plasma, and various internal organs contained rich stores of carotenoids, notably canthaxanthin and varying amts. of astaxanthin in some sites, and many other apparently oxidized carotenoids not yet completely characterized. Astaxanthin was found in adult feathers of P. ruber and in the exposed leg-skin of both species (esterified in P. chilensis), but was not detected in the plasma or in any of the internal organs or tissues examd. Another flamingo Phoenicoparrus jamesi, was found to deposit both canthaxanthin and astaxanthin in its feathers. No carotenoids were detected in the pale feces taken from the intestines of freshly-dead adults. Aerobic and anaerobic bacteria from P. ruber gut exhibited dehydrogenase activity on a no. of substrates, and altered astacene chem. Representative concns. of total carotenoids (mg./100 g. dry wt.) in 4 prominent depots were: tarsal skin 270, feathers 32, blood plasma 5, and egg yolk 4. Newly-hatched chicks had no detectable carotenoids. After about 8 days the skin on the legs turned black with melanin deposits. Red carotenoids were later deposited in new feathers and in the naked leg skin, gradually replacing melanin in the latter as the young birds grew towards adulthood. The effects of solvents and the presence of natural oils on the absorption spectra of carotenoids, and the possible physiol. implications of skin carotenoids are discussed.
Related Structure from CAS REGISTRY
CAS Registry Number: 7542-45-2
3,3'-dihydroxy-beta,beta-carotene-4,4'-dione
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Updated: 2/10/2010 1:44:21 PM
