Kerala is home to a new species of catfish with no eyes 

There are still things in the animal world that continue to remain a mystery to us. Sometimes, these mysteries unveil on their own. Well, that is exactly what happened in Kerela recently. Turns out, a brand-new species of catfish has been discovered there by a group of Indo-German scientists. It is 32 millimetres in size, has a blood-red body with its eyes missing.  

It has been named Horaglanis populi and belongs to the genus of Horaglanis of catfish, that is a diverse group of ray-finned fish. According to experts, members of this genus are usually three centimetres and prefer to live in lightless environment.  

The study that has been published in the journal Vertebrate Zoology was part of a broader Citizen Science Project. Scientists believe that this latest discovery will help them find out more about the distribution of catfish, their genetics and evolutionary history.  

At present, 289 species of catfish have been identified from subterranean marine ecosystems such as the one in Kerela. Around 10 per cent of them, including Horaglanis populi choose to live in aquifers (underground layer of water having porous stones, earth and gravel). What’s interesting here is that, this wasn’t a chance discovery as the team led by Ralf Britz, a German marine scientist based at Senckenberg Natural History Collections have said that they have been conducting a six-year-long study of water-bearing laterite rock layers and the unique flora and fauna found in it with respect to Kerela.  

Sources also cite that these fish live exclusively in aquifers and are very small, perfectly blind with missing pigments. They also stay hidden most of the time and only come to the surface when a domestic well is dug. Members of University of Kochi and Shiv Nadar Institution of Eminence, Delhi-NCR, who were also involved in the study said that they greatly relied on the support and cooperation of local citizens and small-scale scientists to make this project a success. Over the last few years, many workshops, focus group discussions and other community-based conversations have happened surrounding the catfish species.  

Apart from generic studies, targeted research was also carried out in wells, above-ground storage tanks, shallow wetlands, water channels, home gardens and crop plantations, besides farmsteads, ponds and caves. Guess what the end result of this was? Forty seven new site detections and 65 new genetic sequences. This data has revealed that the Horaglanis populi are endemic to Kerela, especially south of Palghat Gap. From what is known so far, the brand-new species although unearthed recently have existed and evolved over millions of years. Till date, 4 such Horaglanis species have been identified. As for the ‘populi’ part, it is Latin for “people” and is a tribute to the invaluable contributions of locals in making this biodiverse discovery a success.  

This study emphasises on the importance of citizen science in expanding our understanding of the natural world and highlights the need for further research into the poorly understood subterranean aquatic habitats of the world.