New frog species discovered in Adi hills of Arunachal Pradesh

The new species was identified based on multiple criteria, such as external morphology, DNA, and calling pattern

A team of Indian and American biologists has discovered a new species of cascade frog from the Adi hills of Arunachal Pradesh resolving a century old taxonomic confusion related to a similar species found in Sikkim 150 years ago.

Scientists from the Wildlife Institute of India, University of Delhi, and North Carolina Museum of Natural Science in the USA named the new species as Adi Cascade Frog (Amolops adicola) after the Adi hills, which are home to Adi tribes, an indigenous group of people from Arunachal Pradesh.

The biologists were investigating a group of medium to large-sized cascade frogs (scientifically belonging to genus Amolops) from Northeast India over the last five years. Cascade Frogs are named so because of their preference for small waterfalls or cascades in flowing hill streams.

Their aim was to resolve a confusion prevalent in the academic circle on the occurrence of a similar frog (Amolops monticola) that was described first in the Sikkim Himalayas 150 years ago.

"There were reports on the occurrence of A.monticola but without the DNA proof. So we decided to explore the Northeastern states looking for it and other species,” Sonali Garg, a team member from the DU told DH.

The new species was identified based on external morphology, DNA, and calling pattern. The study, Garg said, resolved the century-old taxonomic confusions surrounding the identity of the Sikkim frog, Amolops monticola.

“The discovery once again is a testament to how little is known about the most threatened animal groups, frogs, in northeastern India. Many frogs in this region are reported to occur widely but, in fact, have relatively small geographical ranges and require special attention for conservation before they go extinct forever. Northeast India is a treasure house of species still unknown to science”, said S D Biju, DU professor and corresponding author of the article.

“The new species was discovered while revisiting the century-old Adi expedition in 2018. It was named after the land of Adi tribe in Arunachal Pradesh where this species dwells particularly during post-monsoon season”, said coauthor Abhijit Das, from Wildlife Institute of India Dehradun.