|Bitis rhinoceros, West African Gaboon viper (a) The snake partly on white |
background and (b) partly on leafy substrate similar to the natural habitat.
The authors suggest that the microornamentation in velvet black regions of the Gaboon viper skin is unique in snakes. Leaf-like microstructures with both nanoridges and hair-like nanoprotuberances that coincide with black skin coloration have not been previously described. Other members of the genus Bitis have less complex dorsal patterns of lower micro-scaled elevation with pits, a structure similar to that of the pale regions of Gaboon viper skin. When the research team coated the scales from the pale regions of skin with gold-palladium they took on a metallic appearance. But when the scales over the black patches were coated the color contrast remained because coated black areas remain black. Thus, the surface structures of the black scales was responsible for the velvet black appearance.
The entire article can be found on-line.
Spinner, Kovalev, Gorb & Westhoff. 2013. Snake velvet black: Hierarchical micro and nanostructure enhances dark colouration in Bitis rhinoceros. Scientific Reports. http://dx.doi.org/10.1038/srep01846