A tiny fish seen in a social media video sparked the discovery of a new genus and species, scientists say. A type of earthworm eel now named Gangaichthys indonepalicus was found living underground in northern India, according to peer-reviewed research published in the journal ZooKeys Monday. Its discovery was credited in the article to a TikTok video posted in 2024. “We came across a video … from the India-Nepal border area that showed a tiny, apparently stygobitic fish, with little melanin and reduced eyes, that had emerged from a borewell,” wrote study authors Akshay Khandekar, Tejas Thackeray, You He, Anil Mohapatra and Ishan Agarwal. They did not link to the video or describe further details in the research article. The eel’s unique look “and the fact that there are no known stygobitic fish known from the region” prompted the research team to head to the area to track it down, they said in a news release about the discovery, using a term for creatures that live in groundwater. Finding the eel seen in the video was “intensive,” they said, involving the identification of potential borewells, seeking of permission from landowners, and finally the pumping of thousands of litres of water by hand. In 2,500 litres, they found only two specimens, one that was damaged and did not survive, and another that was intact and could be photographed and studied. The researchers believe it’s a previously undiscovered fish, and describe it as about four centimetres long. The eel’s appearance is a result of adaptation to life spent in darkness, they said in the news release, explaining its “eyes covered by skin, an unpigmented translucent body, and an apparent absence of ribs.” Imaging from a micro-CT scan shows a tiny jaw, vertebrae and tail bones. Genetic testing identified it as a distinct species, but within the earthworm eel family known as chaudhuriidae. They named it Gangaichthys indonepalicus, a nod to the location of its discovery. “Gangaichthys means fish of the Ganga,” said Agarwal in a news release. “The Ganga or Ganges is one of the most important rivers in India, both as a source of fresh water, food and livelihood for millions of people; besides having an important role in the Hindu religion.” The fish was found living beneath the Indo-Gangetic Plain in Bihar, and is the first subterranean fish found in the Gangetic Basin. “Indonepalicus” comes from its location on the border between India and Nepal. Calling it an “exciting discovery,” Agarwal said the fish was likely one of many yet-to-be-identified species in the area, given the size and diversity of India in terms of climate and topography.
