In a collaborative effort between Indian and German researchers, led by Dr. Ralf Britz of Senckenberg Natural History Collections, a groundbreaking discovery has been made in the southern Indian state of Kerala. The team, including scientists from the University of Kochi and Shiv Nadar University, conducted a comprehensive six-year study on the catfish genus Horaglanis, thriving in the darkness of local aquifers.
Published in the journal Vertebrate Zoology, the study utilized a unique Citizen Science approach, engaging local communities to contribute valuable information on the distribution, genetics, and evolutionary history of these tiny, three-centimetre-long catfish. The researchers discovered a new species, Horaglanis populi, through genetic studies, expanding our understanding of the subterranean aquatic habitats.
Dr. Britz emphasized the significance of this almost unknown biotope, with less than 10% of the 289 known fish species in subterranean aquatic habitats residing in aquifers. The Horaglanis genus, characterized by its small size, blindness, and lack of pigments, posed a challenge for study, as these elusive fish typically surface during well-digging or cleaning activities.
The collaboration with local citizen scientists proved instrumental in documenting the biodiversity of these hidden species. Workshops, focus group discussions, and informal conversations were conducted over the six-year period, involving communities at various sites, including type localities of known Horaglanis species.
The researchers employed a multi-faceted approach, combining citizen science with targeted collection efforts using nets and traps in wells, wetlands, water channels, home gardens, and plantations. The data collected revealed 47 new site detections and 65 new genetic sequences, highlighting the genetic diversity of Horaglanis in the region.
The newly identified species, Horaglanis populi, measuring no more than 32 millimetres and characterized by its eyeless form and blood-red body, was named in honour of the Latin word for ‘people’—populi. This acknowledges the crucial role played by the local population in contributing to the research and the discovery of the new species.
Despite their small size, species like Horaglanis populi are at a high risk of extinction, particularly due to threats posed by groundwater extraction and mining in densely populated landscapes. The study emphasizes the need for a comprehensive conservation approach involving stakeholders, including the local population, to ensure the survival of these enigmatic subterranean catfishes in Kerala.
Source: Senckenberg Research Institute and Natural History Museum
