Researchers discover a new catfish species, Exostoma nasibarbatum, in Bupal stream in Manipur’s Chandel district.
IMPHAL — Researchers in Manipur have discovered a new species of glyptosternine catfish, named Exostoma nasibarbatum, in a remote stream in Chandel district.
The discovery was reported in the Journal of Natural History, a scientific publication covering zoology and related fields.
The new species was identified by Dr. Bungdon Shangningam, Assistant Professor in the Department of Zoology at Dhanamanjuri University, and PhD scholar Paya Torisha Anal, following an ichthyological survey of the Bupal stream, a tributary of the Dujang river within the Chindwin river system along the India-Myanmar border.
According to the study, Exostoma nasibarbatum can be distinguished from other closely related species found in the Chindwin-Irrawaddy drainage by its distinctive morphological features and adaptation to swift, turbulent waters with boulder-strewn and rocky substrates.
Speaking to this reporter, Dr. Shangningam, a former scientist with the Ministry of Environment, Forest and Climate Change, said the small hill-stream catfish was unique and rarely encountered in the remote areas of the Dujang river.
He added that this was the second fish species to be described from the Chakpi river system in Chandel district.
The species possesses several morphological adaptations that enable it to survive in torrential habitats.
These include a strongly flattened head and body, enlarged paired fins with adhesive striae, and flattened maxillary barbels that help it attach to rocky substrates.
The species has been named nasibarbatum in reference to its prominent nasal barbel, which extends beyond the posterior margin of the eye socket.
The name combines the Latin words nasus, meaning nose, and barba, meaning beard, referring to the elongated sensory organ near the nostril.
The study noted that the genus Exostoma currently comprises 23 valid species distributed across major river systems in Southeast Asia and the Indian Subcontinent.
Of these, seven are recognised as valid species in the Chindwin-Irrawaddy drainage.
The researchers collected specimens of the genus Exostoma during a recent survey of the Bupal stream.
Detailed morphological examinations subsequently established that the specimens represented a previously undescribed species.
Dr. Shangningam has identified 39 new fish species since 2012, mostly catfishes, from various rivers, streams and other water bodies in India and Myanmar.
The discovery of Exostoma nasibarbatum in the remote and largely inaccessible streams of the upper Chindwin basin in Manipur points to the possibility of continued speciation in the region over evolutionary time, the study observed.
The finding also underscores the need for further exploratory surveys, particularly in areas that remain scientifically underexplored.
Northeast India is home to numerous species that are locally known but have yet to be scientifically documented.