This species is found in Thailand, but not within Bangkok itself
English name: Puff-faced Water Snake (aka “Banded Swamp Snake”, “Masked Water Snake”, “Linne’s Water Snake”)
Scientific name: Homalopsis buccata
Thai name: งูหัวกระโหลก (Ngu Hua-kra-lok), งูเหลือมออ (Ngu Leuamao)
Description: To 123cm long. Robust, somewhat flattened body. Notable broad, brown head with dark eyestripes, a “V” marking on top of the head and an inverted “Y” on the snout. Body has broad dark brown to black bands spaced by narrow light bands or saddle-blotches that fade in old age. Underside is white to yellow with small black dots.
Relevant scale counts: 33-40 midbody scale rows, keeled dorsal scales, single frontal, 1 postocular/1 postsubocular, and usually fewer than 166 ventrals.
Similar Species: Jack’s Water Snake has slightly narrower bands with higher contrast, 40-49 dorsal scale rows and usually more than 165 ventrals.
Martaban Water Snake has black-outlined saddle-shaped blotches that appear less like bands, usually has a divided/broken frontal and 39-43 midbody scale rows.
Dog-faced Water Snake has black bars that are narrower than the light background and has dorsolaterally protruding eyes
Bocourt’s Water Snake is thicker and darker with black markings interspersed with the brown and lacks a dark facemask.
Red-tailed Pipe Snake has a small, dark head, smooth scales, and a barred underbelly.
Range: Southern Thailand, Malaysia, Singapore and Indonesia.
Habitat: Rivers, lakes, ponds, swamps, rice paddies, drainage ditches, and any other lowland habitat with water, including brackish water. Can be found in the water or on the banks. During the day it hides in burrows and crab holes.
Place in the ecosystem: Puff-faced Water Snakes eat fish, crustaceans, and frogs. Juveniles of the species are eaten by larger snakes, large fish, monitors, and wading birds.
Danger to humans: Can bite, but rarely does so and is not dangerous to humans.
Conservation status and threats: Due to its broad distribution and ability to live in human-altered habitats, this snake is not considered at risk, though it is listed as Vulnerable in Singapore. It is becoming popular in the pet trade, but that has only had an effect on populations at the local level. In nearby countries similar species are declining due to massive collection for food, skins and crocodile feed.
Interesting facts: The constantly updated research into taxonomy can sometimes make snake names confusing to keep up with. The Puff-faced Water Snake, Homalopsis buccata, was once considered to occupy a huge range throughout southeast Asia. However, scientists studying the Homalopsis genus have found that it is actually comprised of five different species. These species are now:
Puff-faced Water Snake (Homalopsis buccata): Found in Indonesia, Singapore, Malaysia, and south Thailand
Martaban Water Snake (Homalopsis semizonata): Found in southern Myanmar and the western coast of south Thailand
Jack’s Water Snake (Homalopsis mereljcoxi): Found in most of Thailand, as well as Cambodia and Vietnam
Deuve’s Water Snake (Homalopsis nigroventralis): Found in the Mekong River Valley in northeast Thailand, Laos, Cambodia and Vietnam
Hardwick’s Water Snake (Homalopsis hardwickii): Found in northeast India, Bangladesh and Nepal
The IUCN Red List: Homalopsis buccata
A Checklist and Key to the Homalopsid Snakes
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Reptiles of South-East Asia