Yellow-spotted Keelback

23 Apr

Xenochrophis flavipunctatus

Yellow-spotted Keelback Xenochrophis flavipunctatus on road

Yellow-spotted Keelback found at dusk near ponds in Payao Province

Yellow-spotted Keelback Xenocropis flavipunctus

Yellow-spotted Keelback at edge of marsh in Prawet

Yellow-spotted Keelback head Xenocropis flavipunctus

Head shot of Yellow-spotted Keelback

Michael Cota Xenochrophis flavipunctatus Pathum Thani

Yellow-spotted Keelback in Pathum Thani (photo by Michael Cota)

Yellow-spotted Keelback Xenocropis flavipunctus Vietnam Alex Krohn 1

Yellow-spotted Keelback trapped in Vietnam (photo by Alex Krohn)

Yellow-spotted Keelback Xenocropis flavipunctus Vietnam Alex Krohn 2

Yellow-spotted Keelback rearing head in Vietnam (photo by Alex Krohn)

Yellow-spotted Keelback Xenocropis flavipunctus Vietnam Alex Krohn

Head shot of Yellow-spotted Keelback in Vietnam (photo by Alex Krohn)

juvenile Common Keelback Xenochrophis flavipunctatus neck

Juvenile Yellow-spotted Keelback found under board in Suan Luang

Michael Cota Xenochrophis flavipunctatus juvenile Nakhon Ratchasima

Juvenile Yellow-spotted Keelback in Nakhon Ratchasima (photo by Michael Cota)

Ray Hamilton Xenochrophis flavipunctatus juvenile Sattahip

Juvenile Yellow-spotted Keelback in Chonburi Province (photo by Ray Hamilton)

English name: Yellow-spotted Keelback (aka “Common Keelback”)
Scientific name: Xenochrophis flavipunctatus (formerly known as Xenochrophis piscator)
Thai name: Ngu Lai-so Suan, Ngu Daeng Hae

Description: Up to 120cm long. Body is roughly cylindrical and of average girth. Eyes are large. Has an olive-brown background coloration with various black streaks and blotches and a row of small yellow or white dots down each side. Two black streaks come down and back from the eye. Juveniles have a characteristic yellow mark on their neck that fades with age.

Similar Species: Checkered Keelback has a black checker pattern on an olive-brown background. It is a close relative and was once considered to be the same species.
Red-necked Keelback is more colorful and has a characteristic red neck. Juvenile Red-necked Keelbacks, which may not have developed the red neck yet, have a large black marking on the back of their neck that juvenile Yellow-spotted Keelbacks do not have.
Asian Water Snakes (subfamily Homalopsinae) generally have broader heads, smaller eyes, and much thicker bodies.
Oriental Rat Snake lacks black markings on the front half of its body.

Habitat: In or near marshes, ponds, or rice patties, sometimes in the middle of urban areas. The Yellow-spotted Keelback is a a strong swimmer.

Place in the ecosystem: The Yellow-spotted Keelback eats fish, frogs, and rodents, helping to control mouse and rat populations in the city. The juveniles are eaten by larger snakes and birds.

Danger to humans: Will bite aggressively when provoked and can draw blood, but is not dangerous to humans. Though it has no venom glands, some people report itching and slight swelling after a bite.

Conservation status and threats: No known conservation threats.

Interesting facts: The Yellow-spotted Keelback will often swallow its prey immediately upon catching it, without constricting or using any other means to kill the prey. As a result, prey is sometimes swallowed live, and some sources report frogs still vocalizing from within the snake.

Snakes of Taiwan: Xenochrophis piscator
On the taxonomy of the Xenochrophis piscator complex
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
Simon & Schuster’s Guide to Reptiles and Amphibians of the World


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9 responses to “Yellow-spotted Keelback

  1. Thailand

    April 30, 2011 at 7:08 am

    Thailand has quite a variety of animals and I am always amazed by the diversity of wildlife I discover when I visit! I am not a snake expert but I always appreciate learning, thanks for the informative post.

  2. Don Landes

    September 15, 2017 at 4:23 pm

    Does this snake occur in green with a yellow under belly? I was bitten yesterday by a green snake, with a shinny skin as this one. But it had more of an arrow shaped head. It’s first bite felt like electricity and showed a sewing machine pattern, like it could not get a good bite. The second bite was a good one, but a quick hard kick dislodged it from the side of my foot. Could it have been a green cat snake. Any assistance would be greatly appreciated, it is obviously not poisonous, since I’m writing this. But I’m just curious. Currently in Ubon Ratchatani in North east Thailand. Thanks to any and all in advance!

    • Asian Herp Blogs

      April 23, 2019 at 5:46 pm

      It’s pretty difficult to say from that description. Many snakes will appear to have an arrow-shaped head while threatened or biting due to how their jaw can spread. And the lack of effects do not mean that it was not a venomous snake, as venomous snakes can sometimes give dry bites with no venomous effects.

      There are a great number of green snakes in Thailand, including the whip snakes (Ahaetulla species), Golden Tree Snake, Red-tailed Green Rat Snake (also called Green Mountain Racer), Green Keelback, Green Cat Snake, and a number of green pit vipers. If you think it looks similar to a Yellow-spotted Keelback, then I would think a Red-tailed Green Rat Snake might be a likely bet.


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