Arunachal Pit Viper-the New Species of Pit Viper Found in Arunachal Pradesh, India

Arunachal pit viper

The Arunachal pit viper, is a species of venomous pit viper endemic to the Indian state of Arunachal Pradesh. It is only known from the village of Ramda in the West Kameng district, where a single specimen was discovered during biodiversity surveys. It can physically be distinguished by its scalation, its acutely pointed snout reminiscent of the hump-nosed viper (Hypnale hypnale), and its brownish dorsal coloration with glossy orange-reddish-brown sides and belly. The last new species of (green) pit viper was described from India 70 years before the discovery of T. arunachalensis. Genetic analysis indicates that the closest relative of this species is the Tibetan bamboo pit viper (T. tibetanus). The single specimen known of this species makes it one of the rarest known pit vipers in the world, though further surveys of the forest habitat will likely reveal more individuals.

Kingdom	Animalia
Phylum	Chordata
Class	Reptilia
Order	Squamata
Family	Viperidae
Genus	Trimeresurus
Species	T. arunachalensis
Suborder	Serpentes
Binomial Name	rimeresurus arunachalensis

How the Arunachal pitviper was found?

A chance encounter during a biodiversity survey in West Kameng district, Arunachal Pradesh led to the discovery of Arunachal Pit-viper.

“The snake was well camouflaged in the leaf litter on a very steep slope and was detected only because it moved. Once alarmed, it formed a flat coil with its head angled upwards”

The snake’s colouration is striking. 

“If you look at it from the top, it appears drab and camouflages well against leaf litter,” Pandit said. “But on the sides and the belly they have a bright orangish colour.”

• Wildlife researcher Rohan Pandit and his teammate Wangchu Phiang first stumbled upon the new-to-science pit viper species in May 2016 while surveying biodiversity in the state of Arunachal Pradesh in India.

• In a new paper, researchers have described this species and named it Trimeresurus arunachalensis, or Arunachal pit viper.

• While the researchers have described the Arunachal pit viper based on a single specimen, they say the species’ unique features distinguish it from all the other known species of pit vipers.

• As for its habitat, Pandit and Phiang found the only known specimen, now deposited at the State Forest Research Institute in Itanagar, Arunachal, in an unclassified forest that adjoins Pakke Tiger Reserve. The closest village to the forest is Ramda, Pandit said, and while the villagers venture there sometimes to collect things like cane, the forest is only mildly disturbed and occurs on very steep terrain.

• Future surveys of the forest may yield more individuals, which can fill in the information gaps. For now, though, the discovery of a new-to-science species has been very exciting, Pandit said. “It just confirms our previous thought process that there would be lots of undescribed species in these forests,” he said.