Mandya, Karnataka – What began as a routine fishing trip in the waters of the Cauvery River has resulted in the formal discovery and scientific description of a new freshwater fish species, highlighting the hidden biodiversity of one of India’s major river systems.
In 2019, a fisherman in Mandya district near the Shivanasamudra Dam caught a dark-coloured fish locally known as “kaage meenu” or “crow fish.” Roughly under a foot long and weighing about a kilogram, the specimen appeared ordinary to local fisherfolk who were familiar with it. However, scientists from the ICAR-National Bureau of Fish Genetic Resources (NBFGR) in Kochi recognised its potential significance while conducting a long-term biodiversity survey of the Cauvery River that began in 2016.
After detailed study involving morphological examination and DNA sequencing, researchers Rahul G. Kumar, Charan Ravi, N.P. Krishnaprasoon, and V.S. Basheer confirmed that the fish represented a previously undescribed species. In April 2026, they formally named it Labeo kaage in a paper published in the Journal of Fish Biology. The name pays homage to the Kannada word for “crow,” reflecting the fish’s distinct dark body coloration.
A Member of the Carp Family
Labeo kaage belongs to the Cyprinidae family, making it a relative of popular food fishes such as the rohu (Labeo rohita). It is the latest in a series of dark-coloured Labeo species identified in the Western Ghats and Cauvery basin in recent years. The research team had previously described Labeo uru and Labeo chekida from the region.
The new species stands out from its close relative Labeo nigrescens through subtle but consistent differences in body shape, fin structure, and genetic markers. Local fishermen’s traditional knowledge proved invaluable: they noted that L. kaage exhibits unique behaviours, such as building small gravel nests, unlike the shoaling habits of similar species. Its distribution also appears centred in the upper reaches of the Cauvery, differing from related fishes found in rivers like the Chalakudi and Periyar.
Significance for Conservation and Science
Only a limited number of specimens (eight collected between 2019 and 2022) have been documented so far, meaning the full geographic range, population status, and conservation needs of Labeo kaage are yet to be fully assessed. The discovery underscores how even well-studied river systems like the Cauvery continue to harbour undescribed species.
This case also exemplifies the powerful synergy between traditional knowledge and modern taxonomy. An everyday catch by a fisherman, when subjected to rigorous scientific scrutiny, has added a new chapter to India’s rich freshwater fish diversity. As researchers continue exploring the Cauvery basin, more such “ordinary” catches may yet reveal extraordinary findings.
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