Anerythrism

Red pigmentation is not synthesized by xanthophores. Yellow pigmentation in the xanthophores is still present. Additionally, yellow pigments in the form of carotenoids are still retained in the xanthophores. This accumulates with age and may be a major contributing factor in the overall appearance of some animals. Typically, anerythristic reptiles appear as black and white animals, with varying amounts of yellow present.