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  • Writer's pictureJasmine Biju

Horaglanis populi: A Newly Discovered Species

An exciting discovery has been made by a team of researchers from India and Germany in Kerala, an Indian state residing on the Malabar Coast. Working in collaboration with citizen scientists, they have identified a previously unknown species of fish that inhabits aquifers and measures approximately three centimeters in length. The evolutionary history based on the data collected suggests this species is indeed the first of its kind.

In a 6 year study conducted by researchers, information was collected on the novel species as well as its unique biotope. This species of catfish live specifically in aquifers, which is a habitat with distinctive characteristics. Particularly, aquifers are regions of saturated rock which are permeable to water and known for their lack of dissolved oxygen, nutrients, carbon, and complete darkness. Thus, the researchers relied on local individuals in order to improve the understanding of the oddities of this species and their habitat. To uphold the authenticity of the data collected, villagers were educated through information sessions on the species and its localities. Their role was vital in providing key images, videos, and information about the rare species.

The team’s research emphasised on Horaglanis, a catfish genus, which had only three known species at the time. This species is characterised by their lack of pigmentation, blindness, and minuscule size. The rarity of this species proposed a challenge for documentation as the organism made itself apparent in few circumstances. Thus, the team led by Dr. Rajeev Raghavan from the University of Kochi engaged in an intensive process of data collection. Particularly, they used methods such as targeting wells, shallow wetlands, ponds, and caves in order to increase exposure to Horaglanis.

Through meticulous and tedious data collection, the team was able to develop 65 new genetic sequences and 47 new site detections of the species. This species is prevalent south of the Palghat Gap, which is a mountain pass that serves as a natural barrier for aquifers. Furthermore, their findings demonstrated genetic diversity among the genus and solidified the characteristics of newly-discovered species, Horaglanis Populi: no eyes, genetically different from other Horaglanis species, red body, and approximately 32 millimeters in length.

Though the results of the Horaglanis research is fascinating and further advances our knowledge of biodiversity, it also highlights the importance of public and local contribution to the sciences. The work of villagers who were more exposed to specific species residing in their particular region was imperative in elucidating the potential for a new species. Furthermore, to support the longevity and survival of this rare species that are susceptible to extinction, it is crucial for the local population to continue to collaborate in order to aid the prosperity of Kerala’s subterranean catfish genus.

Works Cited

  1. “Evolution in absolute darkness: New Fish Species Discovered in India.” Phys, 15 Feb. 2023,

  2. Evolution in the dark: Unexpected genetic diversity and morphological status in the blind, aquifer-dwelling catfish.” Vertebrate Zoology, 23 Jan. 2023,


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