Scientists at the National Bureau of Fish Genetic Resources (NBFGR) led by Kuldeep K. Lal, who is director of the Fish Genetics Resources Centre under the Indian Council of Agricultural Research (ICAR), have discovered a new catfish species of the genus Pangasius, from the Cauvery. The newly discovered fish species has been named after the ICAR as Pangasius Icaria.
The species has been described based on specimens collected through exploration of the river at Mettur in Tamil Nadu and in the upstream of Shivanasamudra Falls at Chamarajanagar in Karnataka.
The fish is known among the local people as Aie Keluthi in Tamil and as Eyegirlu in Karnataka. The researchers used extensive morphological analysis, skeleton radiography and advanced molecular markers combined with species delimitation computational techniques to conclude that the Pangasius specimens from the river are distinct from other species of genus Pangasius.
The new species can be distinguished from its congeners known from South and South East Asia due to the presence of widely placed, small rounded vomerine (a thin, flat bone forming the inferior part of the nasal septum), palatine tooth plates, and mandibular barbels (barbels are whiskers-like and are sensory organs), among other features.
A senior scientist from the NBFGR said the discovery of the previously unknown species of genus Pangasius from the Cauvery addresses, among other questions, the earlier paleobiogeographic conflict regarding migration of the genus till the southern division of the Western Ghats.
A total of 22 species of Pangasius are known from the river basins of South East and South Asia. However, only one species was known from South Asia for over two centuries till the ICAR-NBFGR discovered a new species from the Nagarjuna Sagar in River Krishna in 2017 and named it Pangasius Silasi. That discovery has been followed by the most recent one.
The latest species, said the senior scientist, is phylogenetically close to Pangasius Silasi. Holotype of this new species is registered at the National Fish Museum and Repository of the ICAR-NBFGR, Lucknow. The name of the species is registered in ZooBank, the online registration system for the International Commission on Zoological Nomenclature (ICZN). The discovery will be published in the international journal PeerJ.
Pangasius catfishes are popular for their commercial value in aquaculture and wild capture fisheries and are considered a delicacy. The discovery is an opportunity for future research on the conservation of the species and evaluation of the new fish genetic resource for its characteristics and utilisation potential.