One of the six ‘bent-toed’ geckos found in Guwahati

Not just remote forests, even crowded cities could be hiding new species. Researchers have discovered six new species of bent-toed geckos – a type of small lizard – from northeastern India, and one of them is from Assam's capital, Guwahati.

While researchers found the Guwahati bent-toed gecko (Cyrtodactylus guwahatiensis, named after the city) near a small hillock in the urban sprawl of Guwahati city, the Kaziranga bent-toed gecko, the Jaintia bent-toed gecko and the Nagaland bent-toed gecko have been discovered from Assam's Kaziranga National Park, the Jaintia hills of Meghalaya and Khonoma village in Nagaland, respectively. The Abhayapuri bent-toed gecko is currently found only in the vicinity of Abhayapuri town in Assam’s Bongaigaon district, and the Jampui bent-toed gecko, only in Tripura’s Jampui Hills. All the new lizards belong to the genus Cyrtodactylus and are called bent-toed or bow-fingered geckos, named after their bent toes.

The discoveries – by an international team from institutes including Bengaluru’s National Centre for Biological Sciences and London’s The Natural History Museum – have been published in Zootaxa. The researchers first searched for geckos along, and south of, the Brahmaputra River in northeastern India. The team then studied in detail the physical features of the bent-toed geckos they spotted in these areas. They compared them with specimens of north-eastern geckos in museum collections across India and the world, including the United States and United Kingdom. They also extracted DNA from the specimens they collected and finally confirmed the six as species new to science.

Unknown natural history

These species are known only from a single locality each, and nothing is known of their natural history, ecology or distribution except that they are nocturnal and live on rocks, said the authors. “They are likely to be narrowly distributed endemic species,” said lead author Ishan Agarwal, who was with the Villanova University in the United States and began working on bent-toed geckos at Bengaluru’s Indian Institute of Science, a few years ago.

“Northeast India probably has dozens more bent-toed geckos,” he added.

The discovery increases the number of bent-toed geckos described from the Himalaya and north-eastern India to 15 (nine of which have been described this year alone). Since 2017, more than 20 new species of bent-toed geckos have been described from Myanmar, too. These new discoveries are a result of surveying areas that have never been sampled before from within the Indo–Burma biodiversity hotspot, said Agarwal.