Opisthotropis lateralis (Boulenger, 1903)
Bicoloured Stream Snake 側條後稜蛇
(Non-venomous)
Opisthotropis lateralis
Order
Suborder		 Squamata 有鱗目
Serpentes 蛇亞目
Family Colubridae 游蛇科
Genus Opisthotropis 後稜蛇屬
Species Opisthotropis lateralis
Other name -
Chinese name 側條后棱蛇 (「后」為繁簡體誤譯，正確為「後」)
Total length Average 30 - 40 cm, can reach 50 cm
Description

Back brown, sometimes with faint fine black line.
Lower sides yellowish-orange, separated with the brown dorsal by a thin black stripe which extends from eye to tail.
Ventrals bright yellow in young snake, become duller in adults.
Head wedge-shaped and flattened. Labials whitish or yellowish. Nostrils open on top of snout.
Body stout and cylindrical. Dorsal scales usually weakly keeled. Lateral scales smooth.
Habitat

Forest streams with gentle gradient. Rare in steep cascading streams.
Recorded in Hong Kong from 100 m to 450 m.
Sympatric with Hong Kong Newt (Paramesotriton hongkongensis), Chinese Waterside Skink (Tropidophorus sinicus), Striped Stream Snake (Opisthotropis kuatunensis), Banded Stream Snake (O. balteata) and Diamond-back Water Snake (Sinonatrix aequifasciata).
Behaviour Mostly nocturnal, may be seen swimming in pools at night.
During day, hide under stone in water's edge or shallow pool.
Inoffensive snake, never attempting to bite.
Diet Feeds on small shrimps, crabs and fish, possibly also on tadpoles.
Reproduction Lays 2-5 eggs among stones close to water in June.
Distribution In Hong Kong, locally common and widely distributed in the north-eastern, central and western New Territories including the Pat Sin Range, Shek Kong, Kadoorie Farm and Botanic Garden, Shing Mun and Tai Lam Chung.
Occurs in southern China (but not from Guangdong) and southern Vietnam.
Conservation Status IUCN Redlist: NE (Not Evaluated)
Opisthotropis lateralis Opisthotropis lateralis Opisthotropis lateralis
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