Fig. 6

Ultrastructural analysis of skin samples from three Galápagos iguana species. A-B) Black-colored skin of A. cristatus. (A) Electron micrograph of A. cristatus skin shows mature melanocytes (arrows). (B) Numerous melanosomes organized in clusters in the superficial loose dermis of black-colored skin of A. cristatus. Scale bar represents 1 μm. (C) The image displays structures resembling xanthophores (arrows) in cells present in the superficial loose dermis of the black-colored skin of the C. subcristatus. Scale bar represents 2,5 μm. (D) Melanosomes cells rich in melanosomes under the epidermis of the black-colored skin of the C. subcristatus. Scale bar represents 5 μm. (E) Melanosomes under the of the black-colored skin of C. marthae. Scale bar represents 2,5 μm. (F) The superficial loose dermis of black-colored skin of C. marthae characterized by numerous collagen fibers (asterisks). Scale bar represents 5 μm. (G-I) Non-black-colored (yellowish) skin of C. subcristatus. (G) Electron micrograph of C. subcristatus skin shows a very dense extracellular matrix rich in collagen fibers and dermoepithelial junctions (square). Scale bar represents 10 μm. (H) Rare melanosomes arrows. Scale bar represents 5 μm. (I) Very large fibroblast-like cells containing xanthophores-like structures (square) in the superficial loose dermis of a C. subcristatus skin. Scale bar represents 5 μm. (J-L) Non-black-colored (pink) skin of C. marthae. (J) Electron micrograph of C. marthae skin. Scale bar represents 5 μm. (K) Cell in the Epidermis without melanosomes. Scale bar represents 5 μm. (L) A vessel containing nucleated red blood cells. Scale bar represents 5 μm