Trimerodytes percarinatus

Trimerodytes percarinatus, commonly known as the eastern water snake, olive keelback, olive annulate keelback or Chinese keelback water snake, is a species of snake in the subfamily Natricinae.

Taxonomy
The type locality for T. percarinatus is Guadun (formerly spelled as Kuatun), Wuyishan City (former Chongan County) in NW Fujian, China.

Subspecies
The subspecies Trimerodytes percarinatus suriki is endemic to Taiwan where it occurs in the whole country.

Description
T. percarinatus is a defensive snake that bites readily when caught, but it is not venomous. It is a medium-sized snake, typically attaining a total length (including tail) of 70 - 90 cm, but may grow up to 110 cm. An adult female usually lays 4 to 13 eggs, but may lay as many as 25 eggs.

Distribution and habitat
T. percarinatus is found in NE India (Changlang District, Arunachal Pradesh), Myanmar (= Burma), Thailand, Laos, Vietnam, S China (Hainan, Zhejiang, Jiangxi, Fujian, Guangdong, Guangxi, Guizhou, Sichuan, Hubei), Hong Kong, and Taiwan. It is an aquatic species associated with hilly areas.

Diet
T. percarinatus preys on shrimps, frogs (including tadpoles), and fish.