|Calotes bachae (credit Peter Geissler)|
The lizard genus Calotes currently comprises 23 species. Some species are known as forest lizards, others as "bloodsuckers" due to their red heads, and yet others as as garden lizards (Calotes versicolor). The latter natively inhabits a large area from East Iran throughout Asia to Indonesia (Sumatra) while the majority of species in this genus are restricted to relatively small geographical regions in India, Sri Lanka and Myanmar.
A group of German and Russian researchers recently collected specimens of the genus Calotes in Vietnam. Based on their general morphology they preliminary identified them as Calotes mystaceus a species indicated as widespread and found mostly in the southern parts of the country with some isolated records known from the north. However, when the looked closer and compared their animals with specimens of Calotes mystaceus from western Cambodia and Thailand they spotted a significantly different color pattern, for example in lacking three characteristic dark brown blotches on the back. This geographic variance was already recognized way back in 1921 and also very recently in 2009. Authors characterized two forms, one on each side of the Mekong River, however nobody made any taxonomic decisions.
Only extensive geographical sampling of comparative specimens and DNA Barcoding have made it possible to distinguish between two genetically distinct units within the specimens currently referred as Calotes mystaceus. As a consequence the authors describe a new species of this agamid genus with the name Calotes bachae. Males of the species impress with their astonishingly rich coloration. During mating season, their azure heads shine bright like in a contest, in order to impress the females. They can also reduce their play of colors, similar to chameleons. For example, at night they appear inconspicuously dark and brownish.