CAROTENOIDS 



Bombinator igneus ; this pigment Kruckenberg named lacertofulvin 

 and in 1917 Schmidt^* found it in crystalline form in the chromato- 

 cytes of, inter alia, L. vivipara. More recently Manunta ^ ^ investigated 

 the carotenoid distribution in an African chameleon (L. viridis). The 

 skin contained predominantly xanthophyll esters, together with small 

 amounts of unesterified xanthophylls and traces of carotenes ; the 

 liver contained free xanthophylls, carotenes and esterified xanthophylls 

 in the ratio 5:3:2, and the eggs almost w^holly free xanthophylls. 

 The xanthophyll fraction from the skin and the eggs could be divided 

 into two components, one of which was very probably lutein 

 (xanthophyll) ; the eyes contained only lutein. Lovenich, von 

 Studnitz and Wigger^^ consider that lacertofulvin which occurs 

 together with ^-carotene and lutein in the skin of L. sicula ^ ^ is identical 

 with their chlorophane extracted from chicken retinas (but see p. 260). 



Many years ago (1885) Halliburton^' demonstrated the presence of 

 lipochromes in the serum and body fat of turtles, but no further work 

 was reported until 1938 when Lederer^^ investigated the Japanese 

 turtle Chrysemys scripta elegans with what can only be considered 

 unexpected results. The red spots on the skin near the eye yielded 

 Y -carotene, the yellow dorsal carapace a-carotene, and the gut a 

 mixture of a-carotene and lutein (xanthophyll). Not sufficient material 

 was available to identify these pigments unequivocally. The skin of 

 Chrysemys terrapins contains a pigment similar to lutein (xanthophyll) 

 but it was adsorbed more strongly on alumina than is lutein and ex- 

 hibited an absorption spectrum with maxima at 450, 475 and 505 mfx. 

 (CSg).^® The retinas of Clemmys insculpta probably contain astaxan- 

 thin. * • The monitor Varanus comodensis stores carotenoids in its liver 

 to about the same extent as do humans {see p. 231), but only about 

 10-20 per cent, of the total is carotene. ' ° 



Fox*i reports that the spiny tailed iguana (Ctenosaura acanthura) 

 excretes a xanthophyllic (taraxanthin) ester in the " hard, waxy, 

 corn-grain shaped, yellow-brown kernels of the femoral pores." 



Villela and Prado^^ report the presence of xanthophylls but no 

 carotenes in the blood of the Brazilian snakes Bothrops jararaca and 

 Eudryas bifossatus ; on the other hand the plasmas of the rattle-snake, 

 Crotalus terrificus and the " boipeva," Xenodon merremii, were devoid of 

 carotenoids. 



The liver of the tortoise, Testudo graeca contains considerable 

 amounts of carotenoids. * ^ 



Function 



Carotenoids probably play a part in the colour changes which 



226 



