Lizard reflectivity change and its effect on light transmission through body wall

Light transmission through the body wall of living, color-labile desert iguanas (Dipsosaurus dorsalis) was measured by spectrophotometry. In the dark phase, the body wall's absorption of ultraviolet light and visible light was approximately twice that of the body wall in the light phase. The shorter wavelengths of ultraviolet could penetrate the body wall in the light phase but not in the dark phase. The intensity and wavelengths of light which could penetrate the body wall without pigments are potentially mutagenic when judged by bacterial standards.