Fluorescescent chameleons, new study

This video from the USA says about itself:

Wild Chameleons in Florida?!

26 April 2016

On this episode of Coyote’s Backyard, the team and new friend David Humphlett discover an animal NONE of them expected to find! In all of their trips to South Florida Coyote and the crew have seen their fair share of amazing creatures. Everything from Alligators and Crocodiles to invasive Pythons and Knight Anoles have crossed their paths, but tonight they find something extremely rare – an invasive but very WILD Veiled Chameleon! Get ready to meet one very cool color shifter!

Although Veiled Chameleons are native to the Arabian Peninsula they have established breeding populations in South Florida in recent years due to favorable climate conditions and an abundance of specimens released from the exotic pet trade. The Chameleon discovered in this video was not released back into the wild and was instead given to an educational/research group.

From the Ludwig-Maximilians-Universität München in Germany:

Zoology: Luminescent lizards

January 16, 2018

Chameleons are known to communicate with conspecifics by altering their surface coloration. Munich researchers have now found that the bony tubercles on the heads of many species fluoresce under UV light and form impressive patterns.

Biogenic fluorescence is mainly known from marine organisms, but is rare in terrestrial vertebrates. “So we could hardly believe our eyes when we illuminated the chameleons in our collection with a UV lamp, and almost all species showed blue, previously invisible patterns on the head, some even over the whole body”, says David Prötzel, lead author of the new study and PhD student at the Bavarian State Collection of Zoology (ZSM). To understand the phenomenon, the researchers used a variety of modern methods. Micro-CT scans showed that the pattern of fluorescence exactly matched the distribution of tubercles pattern on the skull. The tissue analyses yielded another surprise: “Our histological 3D reconstruction shows that the skin covering the tubercles on the skull is very thin and consists only of a transparent layer of epidermis”, explains Dr. Martin Heß from the BioCenter of Ludwig-Maximilians-Universität (LMU) in Munich. These patches effectively act as windows that enable UV light to reach the bone, where it is absorbed and then emitted again as blue fluorescent light.

“It has long been known that bones fluoresce under UV light, but that animals use this phenomenon to fluoresce themselves has surprised us and was previously unknown”, says Dr. Frank Glaw, Curator of Herpetology at the Bavarian State Collection of Zoology.

The tubercles fluoresce under UV light to form distinct patterns that represent certain species or species groups. In addition, the males in most species of the genus Calumma have significantly more fluorescent tubercles than the females. Therefore, the researchers suspect that this fluorescence is not a mere coincidence, but helps the chameleons to recognize conspecifics, and presents a consistent pattern in addition to their skin-based colour language — especially as blue is a rare colour and easily recognisable in the forest.