Guwahati: In a significant boost to India’s reptile records, researchers have documented two rare snake species in the country for the first time—both previously known only from Myanmar, highlighting the ecological importance and still-unfolding biodiversity of Northeast India.
The study, published in the Journal of Threatened Taxa, was conducted by Sourav Dutta, Bitupan Boruah, and Abhijit Das of the Wildlife Institute of India.
The researchers report the presence of two natricine snakes—Kachin Hills keelback (Hebius gilhodesi) and Rakhine keelback (Herpetoreas davidi) in India based on a combination of mitochondrial DNA analysis and detailed morphological examination. Until now, both species were known only from limited localities in Myanmar.
The discovery emerged from extensive field surveys carried out between 2021 and 2023 across Arunachal Pradesh, Meghalaya, and Mizoram. During these expeditions, the team encountered snake populations that did not match descriptions of any known Indian species, prompting further genetic and taxonomic investigation.
The results were striking. The identification of Hebius gilhodesi extends its known distribution westward by over 100 km, while Herpetoreas davidi shows a dramatic range extension of nearly 577 km into India—one of the more significant shifts recorded for snakes in the region.
Field observations revealed that Hebius gilhodesi inhabits forest streams in tropical evergreen and semi-evergreen habitats. The species was recorded in biodiversity-rich areas such as Namdapha Tiger Reserve and Kamlang Tiger Reserve in Arunachal Pradesh, often during nocturnal surveys between 7 pm and 10 pm. The forest floor in these regions, covered with ferns and dense undergrowth, provides ideal microhabitats for such elusive reptiles.
In contrast, Herpetoreas davidi was recorded from Ngengpui Wildlife Sanctuary in Mizoram, where it was found among leaf litter along a stream in lowland evergreen forest. The presence of both species in such habitats underscores the importance of small forest streams and undisturbed microhabitats in sustaining reptile diversity.
The findings also reinforce the role of Northeast India as a critical biogeographic corridor linking the Indian subcontinent with Southeast Asia. The region falls within the Indo-Chinese zone and is known for its high species richness and endemism. Over the years, several new species and distribution records have emerged from this landscape, yet large parts remain biologically underexplored.
Beyond expanding species lists, the study has important conservation implications. Accurate documentation of species distribution is crucial for habitat protection, especially in ecologically sensitive areas facing increasing developmental pressures. Species that remain undocumented are often overlooked in conservation planning, making such discoveries vital for informed decision-making.
The researchers also relied on advanced genetic tools, including mitochondrial DNA sequencing of the Cytochrome-b gene, to confirm species identity—highlighting the growing role of molecular techniques in modern taxonomy.
As the authors underline through their work, Northeast India continues to hold hidden biodiversity waiting to be documented. Each new discovery not only reshapes scientific understanding but also reinforces the urgency of conserving these fragile ecosystems.
In landscapes where streams cut quietly through dense forests, some of India’s rarest species are still being found—one survey at a time.