Guwahati: Tripura has a gecko species to its name, while the one found in Bengal has been named after a herpetologist.

Two new bent-toed geckos have been discovered by Ishan Agarwal as a follow-up of his PhD work at the Centre for Ecological Sciences, Indian Institute of Science, Bangalore.

The two species are Cyrtodactylus tripuraensis (from Tripura) and Cyrtodactylus bhupathyi (from Bengal). The new species has been reported in the current issue of the Zootaxa journal.

"They are commonly called bent-toed geckos because of their bent toes," Ishan Agarwal told The Telegraph. The others who co-authored the paper are Stephen Mahony, Varad B. Giri , R. Chaitanya and Aaron M. Bauer.

The team which helped Ishan are from the British Museum, Villanova University and National Centre for Biological Sciences.

They are the most diverse genus ( Cyrtodactylus) of geckos with over 250 described species. Members of the Cyrtodactylus have slender, curved toes and hence are called bent-toed geckos and they are mostly nocturnal. With the discovery of the two new bent-toed species, the Northeast has now five bent-toed species.

Both the species were found in 2010.

"They are out at night and one can spot them by eye-shine. In Tripura, we surveyed across the state and the species is found all across low elevations and in Bengal we found it close to the highway near a town," he said. "There could be more from the Northeast," he said.

Comparisons were made with material in the collections of Bombay Natural History Society, California Academy of Sciences, Centre for Ecological Sciences, Natural History Museum, UK and Zoological Survey of India.

Bhupathy's bent-toed gecko, Cyrtodactylus bhupathyi was described on the basis of adult female collected near Bagdogra, Darjeeling in Bengal on October 28, 2010.

The species is named after the late Subramaniam Bhupathy for his contributions to Indian herpetology. Bhupathy passed away in 2014 in an accident, while conducting fieldwork in the Western Ghats.

"This species was encountered during approximately one-and-a-half hours of fieldwork after sunset along a national highway. They were spotted by eye shine on a loose stone wall along the side of the road on the edge of lowland moist deciduous forest," he said.

Tripura bent-toed gecko Cyrtodactylus tripuraensis was found from Chobimura, Gomati district, on November 10, 2010. The species is found across the lowlands of Tripura. These geckos were always collected from the ground and mainly from muddy road cuts in secondary and degraded moist deciduous forest.

According to Agarwal, "The geckos are found in neighbouring regions of eastern and southeastern Bangladesh, and southern Assam (Karimganj district)."

He said the Northeast and the Eastern Himalayas are immensely biodiverse and poorly studied, with the few molecular studies of herpetofauna revealing endemism at various scales and imprints of a history spanning many millions of years.

Systematic biodiversity inventories across this mountainous landscape are essential to uncover the vast undescribed biodiversity of the region, before much of it is lost forever.