Family : VIPERIDAE
Species : Trimeresurus albolabris
Maximum Size : 104 cm

The White-lipped Pit Viper was first described in 1842 by E. J. Gray. It remains one of the 'classic' pit vipers of the Southeast Asia region and maintains its scientific name of Trimeresurus albolabris to this day.

It occurs in a variety of forest types and secondary habitats including the margins of agricultural areas and rural gardens. It also known from a wide range of elevations, from lowlands up to 3000 metres.

Reaching just over one metre in total length, this snake is typically found lying in low vegetation in a 'strike pose', waiting for passing prey; it feeds on a variety of vertebrates including lizards, frogs, rodents and small birds.

The colour of this snake is bright green or yellowish-green; the area below the eye and the lip scales are pale in colour (either white, yellow or pale green). The iris is yellow or orange, and the dorsal surface of the tail is reddish. Males have a narrow white stripe along the lower part of the flanks, however females lack this feature.

Trimeresurus albolabris is widespread. Within Southeast Asia it is known from Myanmar, Thailand, Laos, Cambodia, Vietnam, southern Sumatra and the island of Sulawesi in Indonesia.  Outside the region it occurs in parts of north-eastern India and southern China.
 

Figs 1 and 2 : Example from a garden, close to an area of rice paddy on the outskirts of Hoi An, Vietnam, measuring an estimated 40 cm in total length. It was found around 2 metres up a tree, apparently lying in readiness for prey (perhaps tree frogs ?). This is a female, as it lacks a white stripe on the lower flanks. Images submitted by an anonymous reader.


References :

Das, I., 2010. A Field Guide to the Reptiles of South-east Asia. New Holland Publishers (UK) Ltd.