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Gitchak nakana: New blind aquifer fish discovered in Northeast India
International researchers find first aquifer-dwelling fish in Northeast India, published in Scientific Reports
A team of ichthyologists from Europe, America and India has discovered Gitchak nakana, the first aquifer-dwelling (phreatobitic) fish from Northeast India, marking the first discovery of previously unknown subterranean fauna in this part of Asia.
The discovery was published in the Nature Portfolio journal Scientific Reports, one of the world’s leading scientific journals, on February 26 this year.
“This new genus and species is the most unusual among other groups due to the complete lack of a skull roof, with the brain covered dorsally only by skin. Subterranean animals are commonly met with considerable fascination by both laymen and biologists,” says Dr Lokeshwor of DM University, a key member of the team.
“While most of these animals have been reported from caves, some species have adapted to other underground habitats. One special subterranean aquatic habitat is aquifers, which are home to a number of invertebrates and fishes.”
Of the more than 300 known subterranean fishes, fewer than 10% have been recovered from aquifers and are encountered only rarely and serendipitously, he added.
According to Scientific Reports, this blind loach was discovered in a dug-out well in Assam, India. It exhibits a number of characters commonly associated with subterranean life, so-called troglomorphies.
The genus name is derived from the Garo word gitchak, meaning red, alluding to the striking red life colour of this loach, while the specific name is derived from the Garo words na·tok, fish, and kana, blind, referring to the absence of eyes in this species.
The team of ichthyologists includes Dr Ralf Britz and Dr Amanda K. Pinion of Senckenberg Naturhistorische Sammlungen Dresden (Germany); Wimarithy K. Marak and Kangjam Velentina from Assam Don Bosco University, Assam (India); Dr Yumnam Lokeshwor Singh from DM University, Manipur (India); Rajeev Raghavan of Kerala University of Fisheries and Ocean Studies, Kochi (India); and Dr Lukas Rüber of the Institute of Ecology and Evolution, University of Bern (Switzerland).
The journey leading to the discovery of this unusual loach has been ongoing since 2018, when it was collected and brought by Wimarithy, a research scholar of Dr Lokeshwor, for identification in the laboratory of Assam Don Bosco University.
Since then, the team has worked on the specimen and formalised the discovery after collaborating with Dr Ralf. As part of the collaborative project, two research scholars under Dr Lokeshwor, namely Velentina Kangjam and Wimarithy K. Marak, visited the Senckenberg Naturhistorische Sammlungen, Dresden, Germany, for analysis of the species.
“Such discovery will add to the list of endemic species of the region and the world,” Dr Lokeshwor, who has so far discovered 25 new fish species, adds.
