New Catfish Species Discovered in Nagaland's Dzuleke River

Discovery and Identification of Exostoma sentiyonoae

• New glyptosternine catfish species found in Dzuleke River, Nagaland
• Described in Zootaxa journal by researchers Bungdon Shangningam and Limatemjen
• Fourth Exostoma species identified in the Barak River drainage
• Holotype specimen (ZSI FF 9871) measures 75.8mm in standard length

Unique characteristics include:

• • Adipose fin attached to upper procurrent caudal-fin rays
  • Tubercles on dorsal-fin spine
  • Slender head (7.7–13.1% of standard length)
  • Long dorsal-adipose distance (16.8–24.6% of standard length)
  • Small eyes (5.1–8.8% of head length)
  • 41 vertebrae

Taxonomic Distinctions and Species Groups

• Researchers proposed two distinct species groups within Exostoma genus:
  • Group I: Adipose fin confluent with upper procurrent caudal-fin rays
  • Group II: Adipose fin separate from upper procurrent caudal-fin rays

E. sentiyonoae differs from related species:

• • E. berdmorei: Shorter dorsal-fin base, longer dorsal-adipose distance, smaller eyes
  • E. gaoligongense: Shorter pectoral-pelvic distance, smaller eyes
  • E. effreni: Wider head, deeper caudal peduncle
  • E. peregrinator: Longer dorsal-adipose distance, shorter anal-fin base

Significance and Future Research Directions

• First Exostoma species discovered in Dzuleke River, Nagaland
• Highlights rich biodiversity in the region, particularly for hillstream fish
• Limited ichthyological explorations due to hilly terrain and inaccessibility

Researchers emphasize need for:

• • Comprehensive inventories and scientific surveys, including genetic studies
  • Studies on distribution patterns and ecological interactions
  • Conservation status assessments for newly discovered species
  • Focus on remote streams and less-explored regions of Nagaland
• Potential to contribute significantly to understanding of fish diversity in:
  • Nagaland state
  • Eastern Himalaya Biodiversity Hotspot
  • Indo-Burma Biodiversity Hotspot