Analysis of the Structure of Anoline Dewlaps Using Multiple Imaging Techniques

Lizards of genus Anolis communicate with a colorful, expandable throat fan called the dewlap.  It is thought that the dewlap is involved with conveying the species, sex, and even size of different lizards.  One of the most interesting characteristics of the dewlap is that color difference seems to play a role in the recognition of species between two lizards.  Anolis lizards have the ability to perceive color, which indicates the significance of the different dewlaps between species.  Even more, Anolis eyes have the ability to see into the ultraviolet (UV) range - something that humans and most mammals cannot do.  The more complicated dewlaps consist not only of different colors in the visible wavelength, but also into the UV range.  It has been shown in other animals from chameleons to butterflies that structural components play a significant role in the reflection of UV light.  Previous studies have not been able to pinpoint the origin of UV reflectance.  We attempted to figure out what structural component of the dewlap allows for UV reflectance.  In order to study the dewlap effectively three different methods of observation were used.  A micro-CT scanner and an OCT scanner were used to reconstruct 3-d images, while a light microscope was used to observe the dewlap cells directly.  The data taken so far will be compared to determine which method was most effective, and the mechanism by which the UV reflectance occurs.