Indo-Chinese Sand Snake

Psammophis indochinensis

Indo-Chinese Sand Snake in Chiang Mai Province (photo by Paul Donatus)

Indo-Chinese Sand Snake from above (photo by Paul Donatus)

Head shot of Indo-Chinese Sand Snake (photo by Paul Donatus)

Captive-bred Indo-Chinese Sand Snake (photo by save-snakes.com)

English name: Indo-Chinese Sand Snake
Scientific name: Psammophis indochinensis (formerly known as Psammophis condanarus indochinensis)
Thai name: Ngu Man-tong

Description: To 107cm long. A slender snake with an oval head. Its upper body is olive to buff with four dark brown stripes, splitting the body evenly into dark and light stripes. Underbelly is yellow with a thin black line bordering each side.

Similar Species: Painted Bronzeback has a black stripe on its side that goes through the eye, a much broader brown area on its back, and a white underbelly.
Buff-striped Keelback lacks the brown stripes on the side of the light stripes, and has dark bands all along the body.
Striped Kukri Snake has a light stripe down the middle of its back, has less distinct striping, has characteristic dark markings on its head, and has a red or pink underbelly.
Rainbow Water Snake is much thicker, is darker with less distinct striping, and is almost always found in the water.

Habitat: Lives in moist open woodland, scrubland, and grassland. Is often found climbing trees and bushes, but will often rest in burrows.

Contribution to the ecosystem: The Indo-Chinese Sand Snake feeds on rodents, frogs lizards, and smaller snakes. This snake is eaten by larger snakes, birds of prey, and monitors.

Danger to humans: Has rear fangs but is not dangerous to humans. The bite may cause some swelling.

Conservation status and threats: Much of this snake’s habitat has been converted into agricultural land, and it is now rarely seen. I know of no one who has seen an Indo-Chinese Sand Snake in Bangkok, and the last sighting I know of in Chiang Mai was more than five years ago. Though it has a wide range the agricultural threats to its habitat exist across its range and it may be in some danger.

Interesting facts: The Indo-Chinese Sand Snake gets its name from its use of habitats with sandy soils, where it takes shelter in the burrows of other animals.

References:
IUCN Red List: Psammophis condanarus
Thailand Snakes! IndoChinese Sand Snake
Michael Cota, personal communication
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Reptiles of South-East Asia

 

Copperhead Racer

Coelognathus radiatus

Copperhead Racer in Hong Kong (photo by Daniel Rosenberg)

Copperhead Racer found in India (photo by Pranoy Kishore)

Copperhead Racer in Vietnam (photo by Eduard Galoyan)

Copperhead Racer at the Queen Saovabha Snake Farm

Copperhead Racer at a Krabi snake show (photo by Randy Ciuros)

Copperhead Racer in Vietnam (photo by Scott Trageser) naturestills.com

Copperhead Racer in striking position in Khao Phra Thaew (photo by khaophrathaew.org)

Copperhead Racer showing expanded neck (photo by khaophrathaew.org)

Copperhead Racer playing dead in Hong Kong (photo by Kevin Caldwell)

Juvenile Copperhead Racer found in office in Phra Khanong

English name: Copperhead Racer (aka “Radiated Rat Snake”)
Scientific name: Coelognathus radiatus (formerly Elaphe radiata)
Thai name: Ngu Tang-ma-prao Lai Keet

Description: To 230 cm long. One of the larger snakes in Bangkok. Body light brown in the front, fading to a yellowish or orangish tan toward the back of the body. Two prominent black stripes run down the first half of each side of the body. Three black lines radiate back from the eye, two slanting downwards and the other running up until it hits a black collar at the back of the head.

Similar Species: Asian Rat Snakes (Ptyas korros and Ptyas mucosus) lack the black stripes on the front half of the body and the unique markings on the head.
Painted Bronzeback has a yellow-to-cream stripe on its body and lacks the markings on the head.
Monocled Cobra lacks the striping on the front half o the body and lacks the markings around the eye.

Habitat: Prefers open grassland and shrubland, but is also found in forests and agricultural habitats. Can be found in urban areas, even where there is only a small pocket of natural habitat. I found a juvenile in a dentist’s office with an overgrown lot nearby.

Place in the ecosystem: The Copperhead Racer feeds on rats and mice and helps control Bangkok’s rodent populations. It also eats birds, lizards, and frogs. Juveniles of the species provide food for larger snakes and birds of prey.

Danger to humans: This snake is aggressive when threatened and is large enough to inflict some damage with its bite. A recent study has found that it produces some venom, quite similar to the venom of cobras. However, it only produces a small amount of venom and does not have venom-injecting fangs, so effects in humans are limited to redness and mild swelling at worst.

Conservation status and threats: In Thailand this snake is common with no known conservation issues, but it is listed as Endangered on the China Red List.

Interesting facts: The Copperhead Racer is a very fast snake that will first try to flee when threatened, but when cornered will lift the first third of its body off the ground, curl its neck and body into an “S” shape, expand its neck vertically and strike aggressively with its mouth open. If that fails, it will sometimes proceeds to play dead as a last resort.

References:
University of Hong Kong: Coelognathus radiatus
Isolation of a neurotoxin (alpha-colubritoxin) from a nonvenomous colubrid
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Snakes of South Vietnam

 

Golden Tree Snake

Chrysopelea ornata

Juvenile Golden Tree Snake found among ornamental plants in Silom

Head shot of Golden Tree Snake

Subadult Golden Tree Snake in Chiang Mai Province

Head shot of subadult Golden Tree Snake

Golden Tree Snake (photo by Ray Hamilton)

Subadult Golden Tree Snake in Chonburi Province (photo by Ray Hamilton)

Golden Tree Snake in Nonthaburi (Photo by Matt Roome)

Golden Tree Snake in Krabi (Image by Nick Baker, ecologyasia.com)

Golden Tree Snake in Krabi (Image by Nick Baker, ecologyasia.com)

Golden Tree Snake killed in Phnom Penh, Cambodia

English name: Golden Tree Snake (aka “Ornate Flying Snake”)
Scientific name: Chrysopelea ornata
Thai name: Ngu Kieo Lai Dok-mak

Description: To 140cm long. A long, somewhat slender snake. Is unusual in that it has keeled ventral scales, which help it to climb trees. Body is green to greenish-yellow with black markings. Head is black and green above the eye and light green below. Underbelly is greenish-yellow to light green.

Similar Species: Whip snakes (Ahaetulla nasuta and Ahaetulla prasina) have a characteristic pointed snout and more slender bodies.
Green pit vipers (Cryptelytrops albolabris and Cryptelytrops macrops) have a triangular head, pits behind their nostrils, and lack the black coloration.

Habitat: Naturally a forest species, but has adapted well to agricultural areas, parks, yards and gardens. Is almost totally arboreal and can climb to significant heights in trees or even the walls of buildings.

Place in the ecosystem: This snake eats lizards as well as bats, mice, and smaller snakes. The juveniles provide food for birds of prey and larger snakes.

Danger to humans: The Golden Tree Snake bites aggressively when captured and is another one of Bangkok’s mildly venomous rear-fanged snakes, but its venom appears to pose no danger to humans. One should always be careful not to confuse it with the more venomous vipers.

Conservation status and threats: No known conservation issues. This species has adapted well to human encroachment and is one of Bangkok’s more common snakes. However, they are often killed by people who mistakenly believe them to be dangerous. I found a dead adult Golden Tree Snake on the outskirts of Phnom Penh, Cambodia that appeared to have been killed by a human.

Interesting facts: The Golden Tree Snake is one of the few “flying snakes”. These snakes cannot actually fly, but glide to some degree by flattening out their body, forming a U-shaped cavity with their underbelly, and twisting in the air as they jump from high branches. It is believed that this behavior is used to move about the forest, catch prey, and as a defense mechanism against predators. They can cover as much as 100m in a single leap if they start from a tall enough tree.

References:
Ecology Asia: Golden Tree Snake
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Snakes of South Vietnam

 

Many-spotted Cat Snake

Boiga multomaculata

Many-spotted Cat Snake (photo by Gernot Vogel)

Many-spotted Cat Snake (photo by Gernot Vogel)

Many-spotted Cat Snake (photo by Gernot Vogel)

Many-spotted Cat Snake (photo by Michael Cota)

Many-spotted Cat Snake in Hong Kong (photo by Rob Ferguson)

Many-spotted Cat Snake yawning (photo by Rob Ferguson)

Young Many-spotted Cat Snake in Hong Kong (photo by Kevin Caldwell)

Many-spotted Cat Snake at night in Hong Kong (photo by Kevin Caldwell)

Head shot of Many-spotted Cat Snake (photo by Kevin Caldwell)

Many-spotted Cat Snake head shot (photo by Rob Ferguson)

English name: Many-spotted Cat Snake (aka: “Large-spotted Cat Snake”, “Marble Cat Snake”)
Scientific name: Boiga multomaculata
Thai name: Ngu Me-ta-ngao Rang-no

Description: To 187 cm long. Body is slender and higher than it is wide. Tail is especially long. Color on top is grayish-brown with two alternating series of dark brown blotches on the back and two smaller rows of dark spots on the sides. Head is large compared to body and somewhat triangular with a black arrow-like marking on top and a black streak from each eye to the corner of the mouth. Eye has a vertical pupil. Underbelly is paler and marked with brown.

Similar Species: Russell’s Viper, a deadly local species, can be confused with the Many-spotted Cat Snake due to its similar markings. However, Russell’s Viper has a thicker body, a broader head, and is rarely found in trees.
Mangrove Pit Viper has a thicker body, a broader head, and larger, less distinct blotches.

Habitat: Lives in well-watered woodland, scrubland, and treed grassland. Is almost always found in trees or bushes. Only active at night.

Place in the ecosystem: The Many-spotted Cat Snake eats lizards, especially geckos. Will also eat small birds and eggs on occasion. It is fed on by larger snakes and birds of prey.

Danger to humans: This snake is not known to be dangerous to humans. Though it is rear-fanged, it usually kills its prey via constriction. If it is able to chew on a person long enough, it is possible that the venom could cause a minor allergic reaction, leading to swelling and itching.

Conservation status and threats: In Thailand this snake is common with no known conservation issues, but it is listed as Endangered on the China Red List.

Interesting facts: The Many-spotted Cat Snake will shake its tail when threatened, sometimes frightening people into thinking that it is a venomous viper.

The Many-spotted Cat Snake’s long Thai name refers both to its resemblance to Russell’s Viper (“Me-ta-ngao”) and to its tendency to take eggs and young birds from “bird’s nests” (“Rang-nok”). Thus one way of translating its Thai name could be “Bird’s Nest Snake like Russell’s Viper”.

References:
Wikipedia: Boiga multomaculata
University of Hong Kong: Boiga multomaculata
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Snakes of South Vietnam
Snakes of Thailand and their Husbandry
A Field Guide to the Reptiles of South-East Asia

 

Long-nosed Whip Snake

Ahaetulla nasuta

Long-nosed Whip Snake in tree in Phayao Province

Long-nosed Whip Snake as found crossing road

Head shot of Long-nosed Whip Snake

Head view of Long-nosed Whip Snake from front

Long-nosed Whip Snake in tree in Bangladesh

Long-nosed Whip Snake gaping mouth

Long-nosed Whip Snake in Chonburi Province (photo by Ray Hamilton)

Juvenile Long-nosed Whip Snake found in grass in Dok Mai

Long-nosed Whip Snake head shot (photo by Mathias Holm)

English name: Long-nosed Whip Snake (aka “Green Vine Snake”)
Scientific name: Ahaetulla nasuta
Thai name: Ngu Kieo Pak Nab

Description: To 190cm long. Long, extremely slender body with a long tail. Elongate head is shaped like an arrowhead, coming to a pointed tip at the snout with an extended scale forming the “nose”. Eyes are large and have horizontal pupils. Body is light green to brown above and white to green below. This snake sometimes exposes white and black markings on the upper body when disturbed.

Similar Species: Oriental Whip Snake lacks final protruding scale at the end of the “long-nose”.
Golden Tree Snake is not as slender, has black markings, and lacks the characteristic pointed snout.
Green pit vipers (Cryptelytrops albolabris and Cryptelytrops macrops) are not as slender and have a broader head and pits behind their nostrils.

Habitat: Forests, grasslands, and everywhere in between. In Bangkok can be found in agricultural areas, empty lots, parks, and gardens.

Place in the ecosystem: Feeds on lizards, frogs, and small rodents. Sometimes also birds and smaller snakes. Is eaten by birds of prey and larger snakes.

Danger to humans: Not dangerous to humans. It has a weak venom that only takes effect if the snake is able to chew for an extended period of time and is not potent enough to cause symptoms past itchiness and mild swelling.

Conservation status and threats: No known conservation issues. Has adapted well to human encroachment, and its ability to blend in to its surroundings allow it to remain relatively unmolested by humans. However, its long length and slow speed make it a frequent victim of cars.

Interesting facts: Though its slender body gives the impression of speed, the Long-nosed Whip Snake is very slow-moving, relying on its camouflage to avoid predators and surprise prey.

One of my photos of the Long-nosed Whip Snake that is shown above has apparently gone viral, being used in numerous photoshopped forms and even showing up in a software company’s ad campaign. While I am happy for anyone to use the photos on this website for educational purposes, it is always best to ask first, and I will not approve commercial uses. A few people have tried to use the photo for their own profit via social media, and only one of them asked me first. Thank you for understanding!

References:
Wikipedia: Ahaetulla nasuta
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
Snakes of Thailand and their Husbandry

 

Red-necked Keelback

Rhabdophis subminiatus

Venomous and Dangerous!

Juvenile Red-necked Keelback found in Hong Kong (photo by Rob Ferguson)

Red-necked Keelback in Hong Kong (Photo by Kevin Caldwell)

Red-necked Keelback eating frog (photo by Kevin Caldwell)

Another Red-necked Keelback in Hong Kong (photo by Kevin Caldwell)

Head shot of Red-necked Keelback (photo by Rob Ferguson)

Red-necked Keelback in Krabi Province (photo by Tom Charlton, venomlogic.com)

Red-necked Keelback in Laos (photo by Thomas Calame)

Red-necked Keelback in Hong Kong (photo by Thomas Brown)

Neck close-up of Red-necked Keelback (photo by Thomas Brown)

Juvenile Red-necked Keelback near agricultural area in Chiang Mai Province (photo by Sjon Hauser)

English name: Red-necked Keelback
Scientific name: Rhabdophis subminiatus
Thai name: Ngu Lai-Sab Ko Daeng

Description: To 110cm long. Body is relatively slender. Color is greenish-gray or olive with red and yellow coloration around the neck. Eyes are large. Juveniles sometimes lack the red neck, but have a large black spot on the back of the neck and indistinct black barring on the body.

Similar Species: Yellow-spotted Keelback is less colorful and lacks the characteristic red neck. Juvenile Yellow-spotted Keelbacks lack the large black marking on the back of their neck that juvenile Red-necked Keelbacks have.
Checkered Keelback has a black checker pattern on an olive-brown background. It also lacks the red neck and the juveniles lack the black marking on the back of the neck.
Buff-striped Keelback has a characteristic white or cream stripe on the side.

Habitat: In moist forests, grasslands, or brushy areas near marshes, ponds, streams, ditches, and rice patties.

Place in the ecosystem: The Red-necked Keelback eats fish and frogs. The juveniles are eaten by larger snakes, large fish, and birds.

Danger to humans: This snake is not aggressive, but will bit if handled or provoked and can cause adverse affects in humans if it is able to work in its venom. These affects may include headache, nausea, vomiting, and severe renal failure (due to procoagulants).

Conservation status and threats: No known conservation threats over its broader range. There is a historic record for Bangkok, but I know of no recent records and it is possible that its habitat in Bangkok no longer exists due to development.

Interesting facts: The Red-necked Keelback was once thought to be non-dangerous, but several recent cases of snakebite from this species have led to serious hospitalizations. In these cases the snake was allowed to bite for an extended period of time, allowing it to work its rear fangs fully into the hand and release its venom. It is highly recommended that this snake not be handled, and if a bite does occur, make sure the snake is removed immediately and seek medical attention as a precautionary measure.

References:
Ecology Asia: Red-necked Keelback
Severe coagulopathy after a bite from a ‘harmless’ snake (Rhabdophis subminiatus).
Wikipedia: Rhabdophis subminiatus
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Reptiles of South-East Asia

 

Tentacled Snake

Erpeton tentaculatum

Tentacled Snake trapped in Vietnam (photo by Alex Krohn)

Another Tentacled Snake trapped in Vietnam (photo by Alex Krohn)

Head shot of Tentacled Snake (photo by Maik Dobiey)

Tentacles of captive Tentacled Snake in Bangkok (photo by Wolfgang Wuster)

Tentacled Snake in aquarium (photo by Chris Harrison)

Captive Tentacled Snake (photo by Chris Harrison)

Tentacled Snake surfacing at Woodland Park Zoo (photo by Nick Michalski)

Tentacled Snakes (photo by Josh More, starmind.org)

Tentacled Snake breathing (photo by Josh More, starmind.org)

Tentacled Snake at Zoo Atlanta (photo by Pierson Hill)

English name: Tentacled Snake (aka: “Tentacle Snake”, “Fishing Snake”)
Scientific name: Erpeton tentaculatum
Thai name: Ngu Kra Daen

Description: To 90cm long. Body is slender and flattened. Head is trapezoid-shaped and has two short “tentacles” that protrude from either side of its snout. Tail is prehensile. Body color can be gray to brown, with different color phases including widely separated short dark bands, much broader dark bands with little separation, or longitudinal stripes. Head has a reddish-brown stripe on each side that runs from the appendage to the eye. Belly is yellowish-brown.

Similar Species: The Tentacled Snake is the only snake in the world with a pair of protruding appendages on its snout. It is also more slender and flattened than the other water snakes in our area.

Habitat: Found in stagnant lakes, streams, and rice paddies, in areas with murky water and vegetation. Can live in fresh, brackish, or sea water. May burrow into mud during dry periods, but otherwise is not found on land.

Place in the ecosystem: Eats fish and occasionally shrimp. Fed on by larger snakes, large fish, monitors, and wading birds.

Danger to humans: Rarely bites. Is a rear-fanged snake, but it has a weak, fish-specific venom and is of no danger to humans.

Conservation status and threats: The Tentacled Snake is common in its range, though there is some harvest for its meat. Like other water snakes it potentially faces declines in the Tonle Sap Lake due to the extensive snake harvest there.

Interesting facts: The Tentacled Snake has one of the most fascinating hunting techniques in the snake world. It ambushes its prey by waiting in a “J” position, with its tail anchoring its body to vegetation and its head curved back towards its body. When a fish swims nearby, the appendages on the snake’s head sense the fish’s movements via disturbances in the water. Once the fish gets close the snake moves part of its body behind the neck, creating a reflex movement in the fish. The snake immediately strikes with its head exactly where it anticipates the fish’s reflex movement to direct it. This is the only snake that is known to induce a flight response in its prey and strike where it anticipates the prey to be going, rather than aiming at its current location. Watch these videos to see the Tentacled Snake in action.

References:
Wikipedia: Erpeton tentaculatum
IUCN Redlist: Erpeton tentaculatum
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
Snakes of Thailand and their Husbandry
Simon & Schuster’s Guide to Reptiles and Amphibians of the World

 

Yellow-bellied Water Snake

Hypsiscopus plumbea

Yellow-bellied Water Snake found on road near ponds in Phayao Province

Another Yellow-bellied Water Snake in Phayao Province

Yellow-bellied Water Snake found in mud in Phayao Province

Yellow-bellied Water Snake found under fish pond rock in Kanchanaburi Province

Close-up of Yellow-bellied Water Snake

Two Yellow-bellied Water Snakes found under rock in Laos

Yellow-bellied Water Snake in Vietnam (photo by Eduard Galoyan)

Yellow-bellied Water Snake eating frog in Hong Kong (photo by Anne Devan-Song)

Yellow-bellied Water Snakes in China (photo by Kevin Messenger)

Yellow-bellied Water Snake showing unusual ventral color (photo by Kevin Messenger)

English name: Yellow-bellied Water Snake (aka: “Plumbeous Water Snake” or “Rice Paddy Snake”)
Scientific name: Hypsiscopus plumbea (formerly Enhydris plumbea)
Thai name: Ngu Pling

Description: To 77cm long. This small water snake has a moderately broad head and smooth scales. It is uniformly dark above with a pale cream to yellow underbelly.

Similar Species: Rainbow Water Snake has a smaller head and colored lines going down its body.
Jagor’s Water Snake has small dark blotches down its sides.
Chanard’s Mud Snake has a pale line down its side and a row of small dark dots above the line.
Sunbeam Snake is iridescent, has a narrow wedge-shaped head, and is whitish-gray on the bottom.
Red-tailed Pipe Snake has a small head and a barred underbelly.
Yellow-striped Caecilian lacks scales, has yellow stripes on the side rather than a yellow belly, and has a distinctly non-snake-like head.

Habitat: Slow-moving rivers, ponds, swamps, rice paddies, and other wetland habitats with stagnant water. Forages from dusk until dawn. Found on land more often than other water snakes, but rarely far from the water.

Place in the ecosystem: Feeds on fish and frogs. Eaten by larger snakes, large fish, monitors, and wading birds.

Danger to humans: The Yellow-bellied Water Snake will aggressively strike when cornered on land, but its small size keeps it from being able to inflict much damage. While it is a rear-fanged snake with some venom, the venom has a limited effect on humans, possibly leading to some swelling in the worst cases.

Conservation status and threats: No known conservation issues. This is a common species in Thailand, though its population in Taiwan is endangered.

Interesting facts: Yellow-bellied Water Snakes are excellent swimmers but move awkwardly on land. When faced with a threat on land, they will sometimes flip their bodies up into the air and backwards with a reverse-striking motion, propelling themselves erratically towards the water.

References:
Snakes of Taiwan: Enhydris plumbea
Reptiles of Hong Kong: Enhydris plumbea
The IUCN Red List: Enhydris plumbea
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

 

Jagor’s Water Snake

Enhydris jagorii

Jagor’s Water Snake from last known remaining population (photo by Daryl Karnes)

Jagor’s Water Snake from Uttaradit Province (photo by John Murphy)

Another Jagor’s Water Snake from Uttaradit Province (photo by John Murphy)

A pattern comparison of Chanard’s Mud Snake and Jagor’s Water Snake (photo by John Murphy)

English name: Jagor’s Water Snake (aka: “Bangkok Mud Snake”)
Scientific name: Enhydris jagorii
Thai name: Ngu Sai-rung Lai Kwan

Description: To 68cm long. A short, thick snake. Head is short and rounded. Body is grayish-brown to dark brown with black blotches in a line down the sides. Underbelly is pale.

Similar Species: Chanard’s Mud Snake has a pale line below a row of small dark spots rather than larger dark blotches.
Jack’s Water Snake is lighter in color with a light barred pattern on body and dark mask on the face.
Bocourt’s Water Snake is much larger and has narrow yellow banding on black/brown background coloration.
Mekong Mud Snake has light lines along its sides and much smaller dark blotches.
Tay Minh Water Snake is similar to Jagor’s Water Snake, but is only found in the Mekong Delta.

Habitat: Found in floodplains, freshwater swamps and shallow marshes, including artificial wetlands and rice paddies.

Place in the ecosystem: Studies suggest that it feeds entirely on fish. Is eaten by larger snakes, large fish, monitors, and wading birds.

Danger to humans: Is an aggressive rear-fanged species and will bite when threatened but is not dangerous to humans.

Conservation status and threats: This species is only known from Thailand’s Central Plain, and in fact only one population is currently known to persist. It is locally abundant there, but human encroachment and the possible draining or pollution of its wetlands are a threat to its current habitat and thus its continued existence. Fishing with gill nets also kills a large number of the snakes. Protection of the snakes in this wetland may be critical to keep the species from extinction.

Interesting facts: References to the current distribution of Jagor’s Water Snake vary widely. Some sources state that it is only found in a single location in Thailand’s Central Plain, others state that it is found broadly in the Central Plain and Southeastern Basin, and still others state that it is a wide-ranging species that can be found in most of Thailand and beyond. Why the discrepancy? It’s likely due to taxonomic confusion. New species are discovered every year in Thailand, and often what was previously thought to a be a single species turns out to be 2, 3, or even 10 or more different species. At the same time, different species discovered in different areas sometimes turn out to have been the same species all along. As these things get sorted out, different references will update their records at different times (or sometimes even refuse to accept the same explanation), and thus such discrepancies arise.

In this case, the problem is likely that a species called the Tay Minh Water Snake is extremely similar to Jagor’s Water Snake but found in other areas, primarily the Mekong River drainage. Jagor’s Water Snake has also been confused with Chanard’s Mud Snake, another species that was once local to Bangkok.

References:
Diet, female reproduction and conservation of Jagor’s water snake, Enhydris jagorii in Bung Ka Loh wetland
A New Thai Enhydris
IUCN Redlist: Enhydris jagorii
IUCN Redlist: Enhydris subtaeniata
Reptile Database: Enhydris jagorii
John C. Murphy, personal communication
Michael Cota, personal communication
A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand
A Field Guide to the Reptiles of South-East Asia
Snakes of Thailand and their Husbandry

 

Rainbow Water Snake

Enhydris enhydris

Rainbow Water Snake found in Pathum Thani Province (photo by Michael Cota)

Rainbow Water Snake in Malaysia (photo by Tom Charlton)

Rainbow Water Snake trapped in Vietnam (photo by Alex Krohn)

Snake in hand, showing underbelly coloration (photo by Alex Krohn)

Rainbow Water Snake in Lake Songkhla (photo by John Murphy)

Rainbow Water Snake in captivity in Bangkok (photo by Wolfgang Wuster)

Juvenile Rainbow Water Snake in Pathum Thani (photo by Tom Williams)

Head shot of Rainbow Water Snake in Lampang Province (photo by Bernard DuPont)

Water Snakes for sale in Vietnamese market (photo by Alex Krohn)

Rainbow Water Snake killed by field worker in India

English name: Rainbow Water Snake (aka “Rainbow Mud Snake”, “Striped Water Snake”, “Schneider’s Water Snake”)
Scientific name: Enhydris enhydris
Thai name: Ngu Sai-rung, Ngu Plaa

Description: To 97cm long. Robust body with relatively small head for a water snake. Scales are smooth and iridescent. Olive-brown above with two yellow or reddish stripes bordered by dark stripes on the top and sides. White to yellow below with a dark stripe or dots down the center of belly.

Similar Species: Yellow-bellied Water Snake has a broader head and lacks colored lines.
Sunbeam Snake has a wedge-shaped head, more iridescent scales, and lacks colored lines on its body.
Red-tailed Pipe Snake lacks colored lines and has a barred underbelly.
Chanard’s Mud Snake has a broader head and dark spots above the line running down its side.
Jagor’s Water Snake has a broader head and dark blotches running down its side.
Mekong Mud Snake has dark markings in addition to light stripes.

Habitat: A highly aquatic species that is always found in or near wetlands. Is found in a wide range of aquatic habitats, including manmade lakes and ponds. Spends most of its time hunting just off the shore, taking advantage of the tangles of vegetation in the mud at the water’s edge. Is rarely seen in the open, preferring to remain underwater or within vegetation mats and tangles. Does not tolerate brackish water.

Place in the ecosystem: Primarily feeds on fish, but also frogs and tadpoles. Is eaten by larger snakes, large fish, monitors, and wading birds.

Danger to humans: Like other water snakes in its family, the Rainbow Water Snake has a very mild rear-fanged venom that does not pose a threat to humans.

Conservation status and threats: Due to its ability to survive in a wide range of habitats and tolerate human encroachment, the Rainbow Water Snake is a common species in Thailand. However, a recent increase in the harvest of water snakes in Cambodia (for food, skins, and crocodile feed) has led to declines in some populations there. As many as four million Rainbow Water Snakes are estimated to be captured from the Tonle Sap Lake every year.

Interesting facts: Water snakes have a number of specialized traits to support their aquatic lifestyle. These include eyes positioned on top of the head (to see prey and threats while remaining underwater), nostrils that can be closed while underwater, and young that are born live (eliminating the need for a dry place to lay eggs).

References:
The IUCN Red List: Enhydris enhydris
Reptiles Magazine: Mud Snakes
Semi-aquatic Snake Communities in the Central Plain Region of Thailand
The Ecology of the Water Snakes of Ban Tha Hin, Songkhla Province, 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