Unique odd-scaled snake species reported

On Oct 14, 2022, Professor Mo Xiaoyang from Hunan Normal University in Changsha, Hunan province, and several members of his research team were conducting a biodiversity resource survey in Tongdao county, Hunan.

They noticed a snake that had been flattened by a passing car. Research team member Li Hui, a student of Mo's, is a passionate wildlife enthusiast and is especially fond of reptiles. He observed the dead snake carefully.

"It was an odd-scaled snake (the common name for snakes of the Achalinus genus), but looked a little different from those we had seen before, with a creamy yellow ring around its neck," Li told Xiaoxiang Morning News.

The team brought the snake back to their laboratory. After a morphological analysis and molecular testing, they found that it differed from other known Achalinus snake species.

The discovery led them to explore the area for more specimens. After considerable effort, they eventually found and collected three live ones, one in Tongdao and two others in Nanshan National Park, also in Hunan.

Mo, Li, another student of Mo's named Zhu Leqiang and five other Chinese researchers recently published a paper in ZooKeys, an international peer-reviewed zoological journal, in which they described the new species of odd-scaled snake. They have named it Achalinus nanshanensis.

Achalinus is a genus of non-venomous snakes found in Japan, China and Vietnam. The publication marks the official debut of the new species, which is also known as the Nanshan odd-scaled snake.

With the discovery, there are now 28 odd-scaled snake species worldwide, and 21 of them are found in China.

They are called "odd-scaled" because their scales do not overlap one another like most snakes, but are instead spread out and lie individually, similar to pieces of a puzzle. They are also known to be burrowers who crawl below the fallen leaves of the forest.

According to the newspaper in Changsha, the research team spent more than a year searching for and capturing the snakes after the first sighting of the dead one.

"Based on just a carcass, we cannot draw conclusions. We must find a live specimen," Mo recalled telling his teammates at the time.

Zhu said: "We spent over 200 days a year in the wild. The Nanshan odd-scaled snake is relatively small, about 40 centimeters long, with a body as thin as a pencil. It often hides in burrows and feeds on small invertebrates like earthworms, making it challenging to locate."

As the snakes are primarily nocturnal, the team set out fully equipped every evening, carrying snake tongs to capture the reptiles as well as emergency medical supplies and flashlights. They meticulously searched forests in the area along streams and under fallen leaves, often returning home as late as 4 am.

Their routine persisted for months. From Tongdao to Nanshan National Park, the team searched along a road running over 100 kilometers, but to no avail.

Just as the team was on the verge of giving up, the new odd-scaled snake finally made an appearance.

It was on the last night of a survey, on Sept 1 last year, when their vehicle experienced a tire blowout on the road, forcing them to spend the night in the wilderness. They decided to take advantage of the situation and search for the snake once more.

"We couldn't give up looking for the snake and decided to make one final attempt," Li said.

They searched for more than 20 km along the road before suddenly spotting two live odd-scaled snakes that turned out to be the species they were looking for.

The team collected the snakes and later conducted further research in the laboratory, studying the reptiles' morphology and molecular identification. The conclusion was reached that the snake was indeed a new species.

According to Mo, a professor at the School of Life Sciences and the Wildlife Conservation Program at Hunan Normal University, the specimens of the Nanshan odd-scaled snake are currently housed in the university's vertebrate zoology laboratory. The team plans to continue conducting in-depth research on the species, including its geographical distribution and biological characteristics.