Reptiles and Amphibians of Thailand

Thailand's Snakes, Lizards, Turtles, and Frogs

Identifying Asian Water Snakes in Thailand

As you may suspect, Asian Water Snakes are almost always found in the water. They exhibit a large range of body types and patterns.

Due to their variety, different Asian Water Snakes can sometimes be mistaken for Sunbeam Snakes, Pipe Snakes, Wart Snakes, Keelbacks, or Sea Snakes.

small Water Snakes with plain bodies

Crab-eating Water Snake
Crab-eating Water Snake White-bellied Mangrove Snake Fordonia leucobalia bangladesh
© Scott Trageser

Strong body and stout head barely wider than neck. Around 25 midbody scales. Usually lacks loreal scale, nasal scales are separated by internasal, and second pair of chin scales are in contact with each other. Found in saltwater and nearby.

Glossy Marsh Snake
Glossy Marsh Snake Cat-eyed Fishing Snake Gerarda prevostiana งูปลาตาแมว singapore
© Noel Thomas

Slightly weaker, more slender body and more discernible head. 17 midbody scales. Loreal scale is present, nasal scales are separated by internasal, and the second pair of chin shields is separated by small scales. Found in saltwater and nearby.

Yellow-bellied Water Snake
Yellow-bellied Water Snake Hypsiscopus plumbea enhydris plumbeous rice paddy snake thailand
Jon Hakim / CC BY-NC-SA

Somewhat distinct head. Often has yellow belly but sometimes cream. 19 midbody scales. Has a loreal scale and has nasal scales in contact. Is only found in fresh-water environments.

heavy Water Snakes with stripes/rows

Rainbow Water Snake
Rainbow Water Snake Enhydris enhydris malaysia
© Tom Charlton

Two light lines on lower side and often two more near top, with no dark spots or other markings. Striated scales. 153-174 ventrals. Only found in freshwater.

Mekong Mud Snake
Mekong Mud Snake Enhydris subtaeniata งูสายรุ้งลาย (Ngu Sai Rung Lai)
Thai National Parks CC BY-SA

Rows of dark spots with light line below bottom row and sometimes between rows. Striated scales. 136-153 ventrals. 2-3 pairs of elongated chin shields, when there are 2 the first pair is longer than the second. Only found in freshwater.

Chanard’s Mud Snake
Chanard's Water Snake Enhydris chanardi
© Exotarium Oberhof

Pale stripe on the 3rd row of dorsal scales with small dark dots just above it and more dark dots at the top of the body. Scales have no striations. Two pairs of flared chin shields with 2nd pair equal or longer than first. Only found in freshwater.

Jagor’s Water Snake
Jagor’s Water Snake (aka: “Bangkok Mud Snake” Enhydris jagorii งูสายรุงลายขวาง
© Daryl Karnes

No lines or stripes, large elongated black blotches run down the sides with smaller blotches on top. Scales have no striations. Two pairs of flared chin shields with 1st pair longer than 2nd. Only found in freshwater.

brown Water Snakes with bands

Jack’s Water Snake
Homalopsis mereljcoxi Jack's Masked Watersnake
© John Murphy

Highly contrasting bands that fade in old age. Light belly with black dots. Single loreal, 40-49 midbody scale rows, and usually 165+ ventrals.

Deuve’s Water Snake
Deuve's Water Snake Homalopsis nigroventralis mekong masked water snake thailand
© John Murphy

Less contrasting bands that fade in old age. Dark belly with white marks. Single loreal, 35-39 midbody scale rows and 159-167 ventrals.

Puff-faced Water Snake
Puff-faced Water Snake Homalopsis buccata malaysia
© Tom Charlton

Somewhat less contrast in bands than Jack’s Water Snake. Light belly with black dots. Single loreal, 33-40 midbody scale rows, and usually less than 166 ventrals.

Martaban Water Snake
Martaban Water Snake mud snake Homalopsis semizonata burma myanmar jens vindum
© Jens Vindum

Light black-lined saddle blotches. Beige belly with highly broken black stripe down each side. Loreal usually divided or broken, 39-43 midbody scale rows, and 153-164 ventrals.

Bocourt’s Water Snake
adult Bocourt's Mud Snake Subsessor Enhydris bocourti
© John Murphy

Very large and bulky. Narrow light bands with black edges and black reticulations in brown. No dark facemask. 27 midbody scales and 123-132 ventrals. Only found in freshwater.

gray/black Water Snakes with bands

Keel-bellied Water Snake
Keel-bellied Water Snake Bitia hydroides malaysia
© Bruce Jayne

Moderate build. Incomplete dark bands on yellow or grayish background. Unusual small body scales with gaps between. Saltwater and nearby.

Dog-faced Water Snake
Dog-faced Water Snake Cerberus schneiderii rynchops
© Michael Cota

Moderate build. Broken dark bands on gray background. Typical body scales with no gaps, usually 23 midbody scales. Saltwater and nearby.

Cantor’s Water Snake
Cantor's Water Snake Yellow-banded Mangrove Snake Cantoria violacea singapore
© Paul Freed

Long and slender with a small head. Mostly complete yellow bands on black background. Saltwater and nearby.

flattened Water Snakes with tentacles

Tentacled Snake
Brittany Steff, Smithsonian

Pattern varies. Has a more horizontally flattened body than other water snakes. Two distinct tentacle-like appendages at end of head.

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