The Department of Zoology of Dera Natung Government College of Itanagar in Arunachal Pradesh has discovered three new species of fish of genus Aborichthys of family Nemachelidae, according to a recent report.
They have been named Aborichthys uniobarensis, Aborichthys barapensis and Aborichthys palinensis. The discovery has been published in international journals like Asian Journal of Conservation Biology, Journal of Threatened Taxa and FishTaxa.
“The three fish species are distributed in streams like Senki, Barap and Palin, which are the tributaries of Brahmaputra river system,” Prasanta Nanda, associate professor and head of the department of Zoology in the Dera Natung Government College, told Down To Earth.
Previously, 11 species of the genus Aborichthys were discovered in the Eastern Himalayan region across a century, starting from the early 1900s. Besides, three of them were outside Arunachal Pradesh — in Bhutan, Meghalaya and West Bengal.
Aborichthys is an elongate and slender-bodied bottom dwelling freshwater stone loach that inhabits the moderate-to-fast flowing water of mountain rivers, streams and drainages of the Brahmaputra river basin, according to Nanda. It is endemic to the eastern Himalaya.
The species is characterised by narrow oblique bars on the body with a black ocellus at the upper extremity of the caudal-fin base and rounded or truncated caudal fin.
Arunachal Pradesh, a land of rivers, is known for its rich biodiversity. The Eastern Himalaya is one of the four major biodiversity hotspots of India. It is endemic to more than 20 per cent fauna of India, including the fish species.
Till date, more than 250 fish species have been identified in the region, which is quite less than its potential, said Nanda.
Major rivers like the Siang, Lohit, Dibang, Subansiri, Kameng, Noa-dihing, along with several other smaller rivers and streams, are flowing towards the Brahmaputra river, he said. It is expected that there should necessarily be the distribution of more fish species due to its diverse aquatic habitat.
Besides, several species have different local names in different districts of the state.
Before studying the impact of climate change, it was necessary to document the unidentified fish species of the Himalayan region, Nanda said. “These species are vulnerable to climate change as it leads to their habitat alteration,” he said.