DERMAL CHROMATOPHORES OF ANOLIS CAROLINENSIS (REPTILIA, IGUANIDAE)

Skin of the back, belly, dewlap and parietal eye were studied as illustrations of the principal variations of chromatophore arrangement and color range present in Anolis carolinensis. The fine structure of the chromatophores, disposed in sharply stratified layers, was investigated. The most superficial chromatophore layer consists of xanthophores, which impart a greenish‐yellow color to the skin. These cells are filled with two types of membrane‐bounded inclusions containing pteridines and carotenoids, respectively. Basal to the xanthophores is a 2–4 cell‐deep layer of iridophores. These cells are filled with undulating layers of birefringent rodlets, presumably guanine, arranged parallel to the skin surface. The most basal chromatophores are large melanophores, positioned above a thick collagenous basement lamella. Migration of melanin granules into the dendritic processes, which terminate at the dermoepidermal junction, cause the lizard to change from green to brown. The back skin, which ranges in color from bright green to brown, contains the full complement of dermal chromatophores. The xanthophore region is much reduced in the cream‐colored belly. The dewlap, which is bright red when extended, bears a thick layer of iridophores through which are scattered melanophores, and erythrophores containing red pigment. The dermis over the parietal eye contains only xanthophores and a basement lamella. Copyright © 1969 Wiley‐Liss, Inc.