''Achalinus niger'', common name black odd-scaled snake or black burrowing snake, is a snake in family

Xenodermatidae Xenodermidae is a family of snakes native to East Asia, South Asia, and Southeast Asia. All species in the family Xenodermidae are small or moderately sized snakes, never more than but typically less than in total length (including tail). They ...

that is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Taiwan.

Distribution and phylogeography

This Taiwan endemic is widespread at elevations of

asl American Sign Language (ASL) is a natural language that serves as the predominant sign language of Deaf communities in the United States of America and most of Anglophone Canada. ASL is a complete and organized visual language that is express ...

. Genetic analyses have indicated three distinct

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

s, a northern one from the

Xueshan Range The Xueshan Range is a mountain range in northern Taiwan. It faces the Chungyang Range on the southeast. The tallest peak of Xueshan Range is Xueshan ("Snowy Mountain"), which has a height of . Shei-Pa National Park is located around the peak ...

, a southern one from the

Alishan Range The Alishan Range () is a mountain range in the central-southern region of Taiwan. It is separated by the Qishan River from the Yushan Range, the tallest range in Taiwan, to the east of the Alishan Range. The highest peak of the Alishan Range ...

and southern

Central Mountain Range The Central Mountain Range is the principal mountain range on the island of Taiwan. It runs from the north of the island to the south. Due to this separation, connecting between the west and east is not very convenient. The tallest peak of th ...

, and Meifeng, a small but very distinct location at the middle of the Central Mountain Range.

Description

''Achalinus niger'' is a small snake growing to a total length of about . The whole body is iridescent under light. Head is small, oval, and without distinct neck. Body is slender and tail is moderately short. Eyes are small, bead-like;

iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...

is black and indistinct. Upper head, body and tail is uniform olive, grayish tan, or black. Mid-dorsal row of scales on body and tail show a dark longitudinal line. Ventral surface is olive-yellow or dark gray. The young are usually black.

Behaviour

It is a nocturnal and terrestrial snake that preys on earthworms, slugs, and frogs. It is non-venomous and not aggressive. Female lays about seven eggs weighing about each.

Habitat and conservation

''Achalinus niger'' occurs in forests, and sometimes, in caves. It is often found in dark and wet microhabitats such in leaf litter or rotten logs. No significant threats are known. It is a Class II protected species.

References

{{Taxonbar, from=Q2822988 Xenodermidae Reptiles of Taiwan Endemic fauna of Taiwan Reptiles described in 1931