Hypsiscopus plumbea
Phayao (Jon Hakim / CC BY-NC-SA) 
Phayao (Jon Hakim / CC BY-NC-SA) 
Phayao (Jon Hakim / CC BY-NC-SA) 
Kanchanaburi (Jon Hakim / CC BY-NC-SA)
English name: Yellow-bellied Water Snake (aka: “Plumbeous Water Snake” or “Rice Paddy Snake”)
Scientific name: Hypsiscopus plumbea (formerly Enhydris plumbea)
Thai name: งูปลิง (Ngu Pling)
Description: To 77cm long. A small water snake with a moderately broad head. It is uniformly olive, gray, or black above and pale cream to yellow below. Some specimens from other countries show faint dotted or netlike patterns.
Relevant scale counts: Smooth scales in 19 midbody scale rows. The nasal scales are in contact.
Similar Species: Glossy Marsh Snake never has a yellow belly, has 17 midbody scale rows, has its nasal scales separated by an internasal, and is restricted to coastlines near marine environments.
Rainbow Water Snake has a smaller head and two colored lines down its sides.
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.
Range: Found from Burma east through southern China and Taiwan and south south through southeast Asia across nearly all of Indonesia.
Habitat: Slow-moving rivers, ponds, swamps, rice paddies, flooded meadows, 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, frogs and tadpoles. Eaten by larger snakes, large fish, monitors, civets, 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 and then take off in a new direction, 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 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
A Field Guide to the Snakes of South Vietnam
Reptiles and Amphibians of Thailand 
What do they eat ?
Fish and frogs.
Hello there! I recently need to give an enormous flashes upwards
for your nice info you have got below on this post.
I’ll likely to end up coming back to your website for more soon.
I think I found one of these on a hiking trail near my dad’s house. We live in southeast Ohio. are these snakes venomous?
The “Yellow-bellied Water Snake” that is found in Asia and the “Yellow-bellied Water Snake” that is found in America are two completely different kinds of snakes. Names can be confusing like that sometimes – there’s no worldwide organization to keep all the common names straight!
But no, the snake you saw is certainly not venomous. Here is a link to what you probably found:
https://nature.mdc.mo.gov/discover-nature/field-guide/plain-bellied-watersnake
Yellow bellied water snake found on the west coast of Central America and on occasion as far north as California belongs to the Cobra family and is venomous.
You’re thinking of the Yellow-bellied Sea Snake, whose scientific name is Hydrophis platurus and which is found in the Pacific Ocean. That is a very different species from this one. You are right that the Yellow-bellied Sea Snake is a distant relative of the cobra and is venomous. But the Yellow-bellied Water Snake, which is only found in fresh water, not salt water, is not dangerous at all.
The FIRST thing most people want to know whey they identify a snake is whether or not it is venomous. and if so, how venomous as to being a danger to people.
Yes, I believe you can see the section where I detail exactly how venomous and potentially dangerous the snake is? That section is included in every snake entry.
For every species which is dangerously venomous, there is a large, conspicuous note right on the very top of the page. However, I’ve felt it unnecessary to include that for the non-dangerous species. Better if they do the work to read the whole account and learn more anyways!
Thanks alot for the informative blog! I have loads of these snake in my soil! I live in the hills near Chiang Mai and preparing my garden beds by deep forking i keep tuning up these guys, they’re very docile.
They will just try to worm theselves back under the earth again, My land is terraced paddy land, with paddy rice either side, so lots of water around. I like them and feel thtat they contribute well to my ecological garden.