Many species of snakes and lizards are able to change color, which helps them avoid detection, regulate their body temperature, and choose mates. But new research on panther chameleons shows that their colorful hides may not only aid in their survival, but might be concealing a range of species never before imagined.
Furcifer pardalis, as it is known to scientists, is a member of the chameleon family that arose around 90 million years ago in Africa. They dispersed to Europe and Asia, and also made it onto the small island of Madagascar. And since panther chameleons occupy a variety of niches on the island, scientists realized this would be the ideal spot to study these remarkable lizards.
In a study published last week in the journal Molecular Biology, researchers from universities in Switzerland and Madagascar sampled 324 chameleons from across their island habitats. They analyzed the creatures' blood, focusing on mitochondrial and nuclear DNA in an attempt to infer genealogical relationships among the lizards. They also wanted to see if the color patterns among male lizards could be correlated with the genetic variation observed in the DNA.
Not only did the male color patterns correlate with genetic variation, but it appears what was once considered a single species may actually represent up to eleven separate species.
Panther chameleons are one of the most spectacular endemic reptiles on the island of Madagascar. They are found primarily along the northern and eastern coasts of the island and can range from shorelines to as high as 950 meters above sea level. They live in trees and bushes and are perfectly at home among populated areas of the island. But what sets them apart from other lizards is their remarkable coloration.
Males are significantly larger than females and sport a diverse range of colors, from bright red, to green, to blue and yellow. Females and juveniles are typically tannish-brown with hints of pink or orange. The bright colors of the males have made them popular items in the exotic pet trade.
Of the 324 blood samples taken, the scientists analyzed 318, and what their results indicate are up to eleven possible species inhabiting the island. They also found that male color patterns correlated nicely with genetic variation and that it enabled the researchers to map out individual habitats of the potential "species."
The researchers warn that their results are preliminary, and that further studies must be completed before species designation is confirmed. But they hope this new information might open the door to future gene mapping approaches in the quest to better understand adaptive color variation among chameleons and other reptiles.