Achalinus niger Maki, 1931

Size

Achalinus niger is a small snake that reaches a total length of approximately 80 cm (31 inches). Its entire body appears iridescent when viewed under light.

Body & Head Shape

It has a small, oval head with no clearly defined neck, a slender body, and a moderately short tail. The eyes are small and bead-like, with a black, indistinct iris.

Dorsal Coloration

The upper surfaces of the head, body, and tail are a uniform shade of olive, grayish tan, or black. A dark longitudinal line runs along the mid-dorsal row of scales on both the body and tail.

Ventral & Juvenile Coloration

The ventral surface of the snake is either olive-yellow or dark gray. Juveniles of this species are typically black.

Distribution & Elevation

This species is endemic to Taiwan, where it is widespread across elevations from 1,000 to 3,000 m (3,300 to 9,800 ft) above sea level.

Genetic Clades

Genetic analysis has identified three distinct genetic clades: a northern clade from the Xueshan Range, a southern clade from the Alishan Range and the southern Central Mountain Range, and a third clade restricted to Meifeng, a small but highly distinct location in the middle of the Central Mountain Range.

Habitat

Achalinus niger inhabits forests and is sometimes found in caves. It is most often encountered in dark, moist microhabitats such as leaf litter or decaying logs.

Conservation Status

No significant threats to the species are currently known, and it is classified as a Class II protected species.