Highlands of diversity: Another new chameleon from the Bale region, Ethiopia

The Bale Mountains in south-central Ethiopia are considered to be one of the most unique centers of endemism, with an extraordinary number of plants and animals that can only be found there. Numerous species are already known from this Afromontane high-elevation plateau, making it a biodiversity hotspot, but ongoing research continues to reveal the presence of so far unknown and undescribed organisms. 

The new chameleon species, Trioceros wolfgangboehmei
Credit: Koppetsch et al.

Zoologists Thore Koppetsch and Benjamin Wipfler of the Research Museum Alexander Koenig in Bonn, Germany, and Petr Nečas from the Czech Republic, describe one such species: a new small-sized chameleon living on the edge of the forest. Their findings were published in the open-access, peer-reviewed life science journal Zoosystematics and Evolution

There were already two species of the chameleon genus Trioceros known to be restricted to the Bale region when Thore Koppetsch and his colleagues discovered another unique representative of this group from the northern slopes of the Bale Mountains. Interestingly, this new chameleon is considered to be part of a species complex of the wide-spread Ethiopian Chameleon Trioceros affinis. Previous studies have indicated divergence between its different populations across the Ethiopian Highlands – with some of them separated by the northern extension of the Great Rift Valley, which also shaped the evolution of early humans. 

Living individual of Trioceros wolfgangboehmei
Credit: Koppetsch et al.

The new chameleon, Trioceros wolfgangboehmei, has a special name. It honours the scientific work of Wolfgang Böhme, senior herpetologist at the Zoological Research Museum Alexander Koenig in Bonn, and his passion for chameleons and other reptiles.

Apart from its biogeographical patterns, the new species also has a characteristic appearance, displaying enlarged spiny scales on its back and tail that form a prominent crest. It usually lives on small trees and bushes at an altitude of above 2,500 m above sea level.

Head detail of the new chameleon, Trioceros wolfgangboehmei
Credit: Koppetsch et al.

“Given the variation in colour patterns and morphology between different populations of these chameleons in Ethiopia, it is likely that these groups still bear a higher hidden diversity than expected, which might be revealed by further ongoing investigations.”

Thore Koppetsch

Furthermore, the research team urges for sustainable preservation and conservation of its habitat to mitigate the impact of human activity.

***

Original source:

Koppetsch T, Nečas P, Wipfler B (2021) A new chameleon of the Trioceros affinis species complex (Squamata, Chamaeleonidae) from Ethiopia. Zoosystematics and Evolution 97 (1): 161–179. https://doi.org/10.3897/zse.97.57297 

Single no more: First females of a Madagascan chameleon described with modern technologies

The first females of a scarcely known chameleon species from Northeast Madagascar have been described. Because of lack of genetic data, X-ray micro-computed tomography scans of the chameleon’s head were used for species assignment. Regrettably, the habitats of this and many other chameleon species are highly threatened by the ongoing deforestation in Madagascar. The study is published in the open-access journal Zoosystematics and Evolution.

Chameleons belong to the most popular animals of Madagascar and have been quite intensively studied in the past. However, many new species are still being discovered and described, and several species are only known by a single or a few specimens. Likewise, the chameleon species Calumma vatosoa from northeastern Madagascar was described in 2001 based on a single male. The identity of females of this species has been unclear until now.

Recently, the PhD student David Proetzel of the herpetology section of the Zoologische Staatssammlung Munchen (ZSM), Germany, found specimens of female chameleons in the collection of the Senckenberg Museum, Frankfurt am Main, Germany, that looked similar to Calumma vatosoa. The problem was, how to prove this? The specimens from Frankfurt were collected back in 1933 and therefore, the extraction of DNA for genetic analysis was not possible anymore.

Researchers of the ZSM have been using X-ray micro-computed tomography scans for a few years to study the internal morphology of organisms in a non-invasive way.

“With the help of Micro-CT you can investigate even the skeleton of very valuable samples like holotypes without destroying them,” explains David Proetzel.

“In chameleons the morphology of the skeleton, especially the skull, contains important characteristics that distinguish different species,” explains the researcher. “Here, the comparison of the skulls of the male and the female showed that they belong to the same chameleon species. With the help of modern technology we could describe females of Calumma vatosoa for the first time, and add another distribution locality of this species.”

“The habitats of many chameleon species, and not only, are highly threatened by the ongoing deforestation in Madagascar and we need rapidly to expand our knowledge about the biodiversity, so that suitable conservation measures can be taken,” he stresses.

###

Original source:

Proetzel D, Ruthensteiner B, Glaw F (2016) No longer single! Description of female Calumma vatosoa (Squamata, Chamaeleonidae) including a review of the species and its systematic position. Zoosystematics and Evolution, 92 (1): 13-21. doi: 10.3897/zse.92.6464