‘Hidden venom’: Scientists discover 5 'Himalayan pit viper' species in Pakistan, region

• International study overturns 150-year-old classification of Himalayan pit viper

• Two newly identified snake species found exclusively in Pakistan’s mountains

• Researchers uncover hidden species using DNA analysis and century-old museum samples

• Study highlights Pakistan’s northern mountains as one of Asia’s least explored biodiversity hotspots

 PESHAWAR: An international team of researchers studying snakes across the Himalaya, Hindu Kush and adjoining mountain ranges has discovered that a venomous snake “long believed” to be a single species is actually “composed of five distinct species concealed under one scientific identity.”

“The snake, commonly known as the Himalayan pit viper or Gloydius himalayanus, inhabits the high mountain regions of Pakistan as well as neighboring areas of India and Nepal,” said Rafaqat Masroor, a prominent herpetologist and member of the research team.

The groundbreaking study, published in the journal ZooKeys, revealed that what scientists and naturalists had identified for more than 150 years as one widespread snake species was, in reality, a complex of five separate species-level lineages.

Three of these newly identified lineages are entirely new to science, including two species found exclusively in Pakistan’s mountainous regions, underscoring the country’s rich and unique biodiversity.

Rafaqat Masroor, who also serves as Curator at the Pakistan Museum of Natural History, led the research in collaboration with scientist Daniel Jablonski of Comenius University Bratislava, who has conducted extensive field research in Pakistan and Afghanistan over many years.

The research team collected specimens from Kumrat Valley in Upper Dir district of Khyber Pakhtunkhwa during September 2020. It was there that the holotype of what is now named Gloydius hindukushensis — the Hindu Kush Pitviper — was discovered after being freshly killed by local villagers who encountered it on a mountain path.

A second newly recognized species, Gloydius hazarensis — the Hazara Pitviper — was identified in northeastern Pakistan between the Indus River and the western Himalayan foothills.

Meanwhile, a third species, Gloydius nepalensis — the Nepali Pitviper — had apparently remained unnoticed in museum collections from western Nepal since the 1970s, without researchers realizing it differed from the species it had long been assumed to belong to.

Scientists employed modern DNA analysis, detailed body structure comparisons, ecological observations and historical museum specimens to unravel the hidden diversity. Some of the museum samples examined were more than a century old. By comparing preserved snakes through museomics with newly collected mountain specimens, researchers were able to uncover previously hidden evolutionary lineages.

The study strongly emphasizes the critical importance of museum collections. Researchers noted that without preserved specimens safeguarded in museums for decades, it would not have been possible to accurately compare historical and present-day snake populations.

The findings also carry significant implications for both public health and conservation, as pit vipers are venomous snakes.

“If five different species were hidden within what was thought to be a single species, their venoms may also differ,” Rafaqat observed.

Scientists said the discovery created an urgent need to investigate the venom characteristics of each newly recognized species. “If someone is bitten by a Gloydius snake in Pakistan, identifying the exact species of the attacking viper could become crucial for understanding venom composition and potentially the treatment response,” Rafaqat added.

Experts believe that a deeper understanding of venom variations could prove vital for improving snakebite treatment and developing more effective anti-venoms in the future.

With five distinct venom profiles now recognized, researchers say the next phase of the study will focus on mapping venom composition across all species to help guide the development of future anti-venom therapies.

Conservation experts also warned that recognizing separate species is essential for protecting fragile ecosystems. A snake once considered common and widely distributed may, in fact, consist of multiple species with far smaller and more vulnerable habitats.

Some of these newly identified species could already be threatened by habitat loss, climate change and environmental disturbances affecting fragile mountain ecosystems.

Pakistan’s northern mountain ranges remain among Asia’s least explored biological regions, and scientists stressed that continued fieldwork, biodiversity research and institutional support for museums are essential for understanding and safeguarding the country’s natural heritage.

The study further demonstrated that even large and seemingly well-known animals such as venomous snakes can still conceal unknown diversity in remote landscapes. Researchers said the unique geography of the region has fostered extraordinary biodiversity that scientists are only now beginning to fully understand.