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Eight new-to-science geckos described from biodiversity haven Madagascar

  • Scientists have described eight new-to-science species of geckos from Madagascar, all about the length of your thumb.
  • They were elevated to species level following DNA studies of what was, for decades, thought to be a single species group of dwarf gecko, Lygodactylus madagascariensis. They add there could be up to 18 distinct genetic lineages.
  • Scientists have found and named at least 150 new-to-science species from Madagascar in the last 30 years, and are still finding more nearly every year. More than 90% of species in Madagascar are endemic, meaning they’re found nowhere else on Earth.
  • Given ongoing threats to the forests and ecosystems in Madagascar, scientists say we may not be finding and naming species quickly enough to know what’s being lost.

On the northern tip of Madagascar, scientists have described eight new-to-science species of geckos, all about the length of your thumb.

For decades, scientists have studied the Lygodactylus madagascariensis species group of dwarf geckos believing it consisted of only five valid species. But after more careful examination of the geckos’ bodies and analyzing their DNA, they confirmed there are as many as 18 species within the species group. Eight of these new to science species have been formally described in the journal Zootaxa as species in their own right.

“This was a remarkable discovery,” Miguel Vences, a professor at Braunschweig Technical University in Germany and the first author of the study, said in a statement. “Four different, closely related species that are almost indistinguishable to us, occurring together in the same place, apparently without interbreeding — this is exceptional, even for Madagascar.”

In Montagne d’Ambre National Park in the north of Madagascar, scientists thought they were collecting one species but discovered that it was actually four different species.

Seven of the new-to-science gecko species found in Madagascar. Image from Vences et al 2022.

“These results highlight how important it is that we continue to collect samples across Madagascar, even of species we think we understand,” co-author Frank Glaw, curator of herpetology at the Bavarian State Collection of Zoology, in Munich, said in a statement. “There is still very much more to discover.”

Scientists have found and named at least 150 new to-science species from Madagascar in the last 30 years. Glaw, who leads almost yearly expeditions to Madagascar from his institute in Munich, said in a 2021 interview with Mongabay that they are still finding new species nearly every year.

Many of the new reptile species found in Madagascar over the past year have been quite small, such as the famed Brookesia nana, possibly the smallest reptile on Earth. The new gecko species are no exception, all measuring about 5-7 centimeters (roughly 2 inches) from nose to tail.

A male Brookesia nana chameleon found in Madagascar and described in 2021. It may be the smallest reptile in the world. Image courtesy of Frank Glaw.

“We think that their small size may play a role in the way they speciate,” co-author Mark D. Scherz, curator of herpetology at the Natural History Museum of Denmark, said in a 2021 interview with Mongabay, “because small animals are generally less able to move from one area to another, and are more likely to get isolated by barriers like rivers cropping up between populations. This could explain why we have seen these kinds of patterns in the tiny frogs, chameleons, and now also geckos that we have been studying in Madagascar.”

Madagascar, a land mass larger than France, broke off from Africa 150 million years ago. In its isolation, the island has become a laboratory for evolution, with more than 90% of its species found nowhere else on Earth.

Montagne d’Ambre National Park, the home of the newly described gecko species, is among the most biodiverse places on the island. It also hosts more than 60 species of reptiles, 75 bird species, and at least 25 species of mammals, including eight species of lemur, the ring-tailed mongoose (Galidia elegans) and the Malagasy civet (Fossa fossana).

A Sanford’s brown lemur (Eulemur sanfordi) in Montagne d’Ambre. Photo by Rhett A. Butler.

Madagascar has lost as much as half of its forests since the 1950s. The remaining ecosystems and biodiversity face threats from deforestation, slash-and-burn agriculture, erosion, soil degradation, overharvesting from the wild, and the introduction of alien species.

Given ongoing threats to the environment, Glaw said, they may not be finding and naming species quickly enough to know what is being lost. “There is a kind of race against extinction,” he said. “I would not be completely surprised if many of these species will be gone by the end of the century.”

Citation:

Vences, M., Multzsch, M., Gippner, S., Miralles, A., Crottini, A., Gehring, P.-S., … Scherz, M. D. (2022) Integrative revision of the Lygodactylus madagascariensis group reveals an unexpected diversity of little brown geckos in Madagascar’s rainforest. Zootaxa, 5179(1), 1-61. doi:10.11646/zootaxa.5179.1.1

Banner image of Lygodactylus hapei by HP Berghof.

Liz Kimbrough is a staff writer for Mongabay. Find her on Twitter: @lizkimbrough_

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