Sinonatrix percarinata suriki

Eastern Water Snake

白腹游蛇 (bai2fu2you2she2)

Status: Not Protected


Colubridae, subfamily Natricinae
Max. length
100 cm
Occurrence in Taiwan
Throughout Taiwan, at elevations of 500-1000 m.
Global Distribution
Endemic to Taiwan.
This snake is small to medium size; total length up to 100 cm. There are 17-19 (19 at mid-body) rows of scales, all strongly keeled except for the outermost row. Head is oval to slightly triangular; body is moderately stout and round; tail is long. Eye is medium to large; iris is yellow, darkened by coarse diffuse black pigment, and pupil is round, slightly off center (toward upper part of eye), black surrounded by ring of dull yellow. Tongue is flesh-colored, darkened by diffuse black pigment. Upper head is uniform dusty gray to olive gray; the labials are slightly lighter than upper head due to light gray mottling. Upper body and tail are gray to dark gray, with irregular cross bands of black or darker gray. Ventral head and neck are dirty white to light cream gray, and the following scales are tinted with gray which become progressively more intense posteriorly. Ventral body and tail also bear scattered quadrangular or irregular marks of blackish pigment which are irregularly arranged on sides. Anal scale is divided and subcaudals are paired.
Biology & Ecology
This cathemeral (diurnal or nocturnal) snake inhabits rivers, creeks and (to a lesser degree) ponds and is especially fond of very clean water. It preys on shrimps, tadpoles, frogs, and fish. Females produce 4-25 eggs per clutch in summer and habitually protect them; hatchlings measure about 17 cm in total length.
When disturbed, the snake can become quite aggressive; it may strike and attempt to bite, and also empty its anal glands for extra olfactory effect.
Sinonatrix: "Sino" is New Latin for "Chinese"; natrix is Latin for "water snake";
percarinata is Latin for "keeled", referring to the snake's keeled scales.
The subspecies epithet suriki is a term used by certain Taiwanese tribes to describe the animal's aggressiveness.
The Chinese name 白腹游蛇 (bai2fu4you2she2) literally means "white-bellied (白腹) swimming snake (游蛇)".