New species of fish discovered in Arunachal

A new species of glyptosternine catfish, christened Exostoma Tenuicaudata has been discovered by scientists of Zoological Survey of India (ZSI).
This is only one of nine species under the Exostoma genus found in the world and second discovery of the genus in over a century, ZSI scientists said.
A team of ZSI scientists caught the fish from Siang river in Upper Siang district here recently and the report of the discovery was published in 'Zootaxa', a New Zealand-based science journal.
Glyptosternines are highly specialised sisorid catfishes with greatly depressed body profiles, enlarged, horizontally extended paired fins, modified for adhesion, typically inhabiting torrential waters in rocky mountain streams and rivers, the report stated.

Genus 'Exostoma' is different from other glyptosternines in having a continuous post-labial groove in the lower jaw, gill openings do not extend on to venter, teeth in upper and lower jaws are homodont and oar-shaped and flattened distally.
It has tooth patches in upper jaw separated, not produced posteriorly at sides, 10-11 (10-12 herein) branched pectoral fin rays, dilator opercula and levator opercula are isolated, anterior end of sternohyoideus is broad and its width is almost equal to that of this muscle in axilla of pectoral fin.
The adductor pelvicalis superficialis partially contacts with its antimere in the midline, the report added.

"Arunachal's rich biodiversity has not been explored yet," ZSI officer-in-charge Bikramjit Sinha who led the team said while advocating its complete documentation.