Iridophore- and Xanthophore-Deficient Melanistic Color Variant of the Lizard Plestiodon latiscutatus

Elucidating the ultimate and proximate mechanisms of melanistic color pattern formation has become an important focus of evolutionary biology. There are relatively few studies, however, examining the composition and architecture of pigment cells in melanistic reptiles. The typical color pattern of the skink Plestiodon latiscutatus, which inhabits the Izu Islands and Izu Peninsula of Japan, consists of brown dorsal coloration, five vivid yellowish white stripes, and a blue tail (in juveniles). We have observed melanistic morphs at a low frequency (