Researchers at the ICAR-National Bureau of Fish Genetics Resources (ICAR-NBFGR) have identified two new specimens of congrid eels off the coasts of Kerala and Tamil Nadu. The discovery of the eels of genus Ariosoma add to the ten eel varieties recently discovered by the national bureau. A senior NBFGR scientist said that the newly identified eels were found off the Gulf of Mannar in Tamil Nadu and off the Kochi coast in Kerala.
The finding adds to the growing understanding of marine biodiversity in Indian waters, particularly about eels, marking a significant step in the ongoing research efforts of ICAR-NBFGR, the scientist added.
The species collected from the Gulf of Mannar has been named Ariosoma kannani (to honour the late Professor L. Kannan, former director of Marine Biology, Annamalai University and former Vice-Chancellor of Thiruvalluvar University) and the species from Kerala coast has been named as Ariosoma gracile based on its morphological characters.
Eels, known as Anguilliformes, represent a fish group that has received limited research attention, particularly in India. Until now, only a handful of research institutes have been studying the biodiversity of the less-explored group in Indian waters.
NBFGR is taking a lead in conducting exploratory surveys in the waterbodies from Himalayas to the Lakshadweep group of islands. As a result, the national bureau has already discovered 10 eels from the Tamil Nadu and Kerala coasts.
The species Ariosoma kannani has been described based on specimens collected through explorations along the landing centre of Rameswaram, Gulf of Mannar region. The researchers conducted extensive morphological analysis, skeleton radiography and advanced molecular markers combined with species delimitation computational techniques to conclude that the congrid eel specimens from the Gulf of Mannar region is distinct from other species of the genus Ariosoma.
The new species from Kochi, Kerala coast, differs from its known congeners by longer tail, dorsal-fin is above to pectoral-fin base, intermaxillary teeth patch separated from vomerine and maxillary teeth by a definite gap and possessing 140-142 total vertebrae. A few specimens of both the species have been sent to the Zoological Survey of India for final confirmation.
The specimens of both species are registered at the National Fish Museum and Repository of the ICAR-NBFGR, Lucknow. The name of the species has been registered in ZooBank, the online registration system for the International Commission on Zoological Nomenclature (ICZN). The discovery was published in Zoosystematics and Evolution.
According to the NBFGR researchers, comprehensive study is needed for better understanding of the species and evolution of these eel groups. The examination aims at grasping the characteristics of the fish group and biodiversity along the Indian coast, they added.
