English name: Bocourt’s Water Snake
Scientific name: Enhydris bocourti
Thai name: Ngu Zi, Ngu Leuam-ao
Description: To 110cm long. With a very robust body, this is the largest of the water snakes in Thailand. Head is large and blunt. Eyes are red. Body has large brown blotches/bands with black borders that narrow on the sides, with yellow bands in-between that broaden correspondingly. Brown areas sometimes have thin tan-to-orange line in the center Both the light and dark coloration becomes more indistinct as the snake ages. Head is reddish-brown with a cream upper lip. Underbelly is yellowish-white.
Similar Species: Puff-faced Water Snake is not as robust, lighter in color, and has a distinct dark face mask.
Rainbow Water Snake has a smaller head and has long stripes running down its body.
Jagor’s Water Snake is much smaller, lacks bands, and has black blotches on its sides.
Yellow-bellied Water Snake is smaller and is uniformly dark above with no pattern.
Habitat: Found in swamps, ponds, shallow lakes, rice fields, and other stagnant waters in lowlands. Is highly aquatic and usually stays near water, but will travel over land during rainy nights. Conceals itself among logs in or near water during the day.
Contribution to the ecosystem: Helps control fish and frog populations. Provides food for larger snakes, large fish, monitors, and wading birds.
Danger to humans: Bocourt’s Water Snake is a rear-fanged species but its venom is not a threat to humans. Though it is not aggressive, its large size and sharp teeth allow it to give a nasty, painful bite.
Conservation status and threats: There are no known serious threats to its Thai populations. However, Bocourt’s Water Snake is harvested for its meat and skins in several countries. In Cambodia’s Tonle Sap Lake, extended overharvest has led to the species being rarely found and it now comprises only a small proportion of the annual snake catch. There have also been declines due to overharvest in Vietnam. In some areas it has begun to be farmed in large numbers, which could relieve pressure on wild populations.
Bocourt’s Water Snake is rare in Bangkok, but may be more common in the rural areas around the city.
Interesting facts: Like many water snakes, Bocourt’s Water Snake releases a foul-smelling musk and feces when handled. Along with biting this is one of its primary defense mechanisms.
IUCN Redlist: Enhydris bocourti
CTV News: Massive snake harvest threatens Cambodian lake
Vietnam News: Water Snakes make invalid soldier a millionaire
Nature Malaysia: Bocourt’s Water Snake
Thailand Office of Environmental Planning and Policy: A Checklist of Amphibians and Reptiles in Thailand
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Reptiles of South-East Asia
A Field Guide to the Snakes of South Vietnam