A new species of ‘crying’ snake has been discovered in Lepa-Rada district of Arunachal Pradesh.

The discovery of the non-venomous crying keelback, whose zoological name is Hebius lacrima, has been published in Zootaxa, the New Zealand-based scientific mega-journal for animal taxonomy.

“The name for this keelback was suggested because of a dark spot under its eyes looking like a black tear that interrupts a white stripe running along the upper jaw to the back of its head and beyond,” Jayaditya Purkayastha, a Guwahati-based zoologist who located the new keelback in the Basar area of Arunachal Pradesh, told The Hindu.

‘Lacrima’ means tear in Latin.

The specimen that Mr. Purkayastha obtained from a paddy field on a hill slope on the outskirts of Basar town was an adult male 48.7 cm long. Photographs of a few other such snakes revealed that was the average length of an adult.

The crying keelback had to be compared with 44 species of snakes worldwide under the genus Hebius. “I had data on 20 species of this genus. So I collaborated with Patrick David of the Paris-based National Museum of Natural History who had data on another 22,” Mr. Purkayastha said.

According to the paper by Mr. Purkayastha and Mr. David, the crying keelback can be differentiated from all other species of the genus Hebius by the combination of a distinctive broad, white, interrupted stripe along its body; three rows of irregular dark blotches (not vertically aligned) on each side; six cream, elongated spots on its anterior part and a smooth dorsal scale row.

The snake, preferring to live near streams along paddy fields, was found to feed on small fish, tadpole, frogs and geckos.

“We are working on many new species of amphibians and reptiles and hope to get the research published by the middle of this year. There is a lot of scope in research pertaining to herpetofauna in northeast India but we need support from government bodies,” Mr. Purkayastha said.

Globally snakes are represented by 3,709 species. The northeast is home to some 110 species, with Arunachal Pradesh accounting for 55.

Several animals, birds, amphibians and insects have been discovered in Arunachal Pradesh in a little more than two decades.

Assam-based Anwaraddin Choudhury discovered the Arunachal macaque (Macaca munzala) in 1997 but it was recognised as a new primate species in 2004. Another primate species called the white-cheeked macaque (Macaca leucogenys) was discovered by a four-member team in 2015.

Another team led by Aparajita Dutta discovered the leaf deer (Muntiacus putaoensis) in 2002.

Another major discovery was that of the Himalayan forest thrush in 2016. It was given the scientific name Zoothera salimalii after legendary ornithologist Salim Ali.