Exostoma sentiyonoae

Sept. 26, 2024

Recently, A new species of glyptosternine catfish- Exostoma sentiyonoae, has been discovered in the Dzuleke River, a tributary of the Barak River in Nagaland.

  About Exostoma sentiyonoae:

  • According to the research paper, the species can be distinguished by several unique characteristics including an adipose fin attached to the upper procurrent caudal-fin rays, tubercles on the dorsal-fin spine, a slender head, a long distance between the dorsal and adipose fins, small eyes and 41 vertebrae.
  • The researchers distinguished Exostoma sentiyonoae from its congeners in the Salween drainage of Myanmar and Thailand, specifically E. berdmorei and E. gaoligongense.
  • sentiyonoae differs from E. berdmorei in having a shorter dorsal-fin base, a longer dorsal-adipose distance, and a smaller eye and compared to E. gaoligongense, the new species has a shorter pectoral-pelvic distance and a smaller eye.
  • It marks the fourth species of Exostoma described from the Barak drainage, highlighting the region’s rich biodiversity.
  • It is the first known member of this genus discovered from the Dzuleke River in Nagaland.

The Bark system:

  • The Barak is the second largest river in the Northeast India after the Brahmaputra.
  • Origin: it originates as a small stream amidst the lofty hills covered by thick forests of Liyai village in the Poumai territory of Manipur.
  • It has a length of about 900 km of which, 564 km fall in India.
  • Drainage:
    • The river runs through Manipur, Nagaland, Mizoram, Assam in India and Bangladesh.
    • The stream is later joined by Deirii stream and Makhan stream as it flows down south through the Biiso valley.
    • The Khiiri stream joins the Barak River before reaching Karong.
    • After crossing the Maram region, the Barak flows southwards into the Zeme, Liangmai and Rongmei territories of Manipur and Nagaland.
    • Finally, Barak flows into Bangladesh to join the Brahmaputra and Ganga.