Mangrove Pit Viper – Venomous – Dangerous

Mangrove pit viper in mangrove trees in Krabi province, Thailand.
Mangrove Pit Viper (Trimeresurus purpureomaculatus) is Dangerous and Bites Frequently. Photo courtesy of Carlton Wagner and Michael Miller, used with permission.
Mangrove Pit Viper - Thailand
Not found near homes much – but, here is one…

Trimeresurus purpureomaculatus – Mangove Pit Viper

Also known as mangrove viper, shore pit viper, Gray’s pit viper, purple-spotted pit viper, and shore pit viper. In the past (2004-2011) this snake was called Cryptelytrops purpureomaculatus.

Thais Say: Ngoo pang ka

Length: Males grow to about 60 cm and females to 90 cm on average.

Habitat: Usually near water and very wet areas like mangroves along the ocean or brackish water. However, recently one was found on a sidewalk by a bungalow on the island of Koh Phi Phi in Krabi province, Thailand. They like stream banks with good cover – low lying plants that they can hide under. They also may like hilly habitat and have been found as high as 2,000 meters elevation in bamboo jungles. These snakes are found in high numbers on islands around Thailand. I have found this species in some abundance along the shore in mangroves in Krabi province.

Behavior: Diurnal and arboreal. These snakes are very easily agitated, and once they get going they are slow to calm down. Their strikes are very fast, but have a short reach. These are known by snake handlers to have a “bad temper.”

These Thailand pit vipers can have many color variations. They are usually like the photo above – greyish with a bit of purple in the coloring. Some are very purple. We’ve also seen a brownish toned mangrove pit viper with some yellow highlights. Now for our top photo we have a greenish toned viper. Obviously – color is highly variable in this species. Tom Charlton found black variations on Langkawi Island in Malaysia, and John Paul Foenander has also found dark, even black, specimens in Singapore.

Venom toxicity: Venomous and very toxic to humans. Though people have died as a result of bites from this snake, this is not usually the case. Symptoms – pain, severe swelling, bruising, blistering, and necrosis are more likely.

Here (it isn’t live any longer) is a study of treating a bite by this snake with T. albolabris antivenom from the Queen Saovabha Memorial Institute with some success.

Treatment: Antivenin is indicated.

Antivenom Name – Green Pit Viper Antivenin (Code – SAsTRC01)
Manufacturer: Thai Red Cross Society
Phone: +66-2-252-0161, 0162, 0163, 0164
Queen Saovabha Memorial Institute
1871 Rama IV Road, Pathumwan, Bangkok 10330 Thailand

Mangrove Pit Viper Scientific Classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Viperidae
Subfamily: Crotalinae
Genus: Trimeresurus
Species: T. purpureomaculatus

Classified as – Trimeresurus purpureomaculatus by Gray in year 1832.

Mangrove pit viper photo courtesy of, and full copyright by – Richard Richert. Thanks Richard!

[Page Updated: 28 November 2019]


Snake posts by Vern Lovic. Amateur herpetologist roaming about Thailand on field herping tours and events to find king cobras, kraits, vipers, corals, keelbacks, and other snakes native to Thailand. FYI - Thailand has over 200 snake species. Here's our latest book with detailed information on Thailand's 35 Deadly Snakes. "Is That Snake In Your House Dangerous? Identify Deadly Thailand Snakes In Under 5 Minutes!" INFO HERE.

10 thoughts on “Mangrove Pit Viper – Venomous – Dangerous

  • February 27, 2013 at 5:13 am

    I think we met one on our bungalow terrace in Koh Phi Phi 2 weeks ago. Brrr… scary, it was just near my foot while I was writing my postcards !
    See the link enclosed

    • February 27, 2013 at 8:09 am

      Hi Celine,

      Yep, that’s a mangrove pit viper (Crypteletrops purpureomaculatus). Here’s the FACT SHEET for it (click) They have a strong venom, and sometimes a strong attitude to go with it. So lucky your foot wasn’t bitten. I wrote you email. Cheers, Vern

  • January 31, 2016 at 2:26 am

    We were in Koh Samui a few years ago in their airport which is outdoor though covered with a roof, with tree’s doted around the seating areas. A snake suddenly fell from one with a huge thud, almost onto my mother, and quickly slinked under her chair while we moved away. It was quite thick and of substantial size though it was hard to tell how long exactly. It was deep black and didn’t seem to have any other colour on it, unfortunately I didn’t get a good look at the head before my dad cleverly pulled me away, which would’ve helped me realise what type it was. I’ve wondered ever since what exactly it was, the employees of the airport were completely terrified and they killed the snake fairly quickly after moving everyone away, when we asked about it they said it’s one of the most venomous snakes on the island. The darker purply black colour of the mangrove pit viper seem to match it best but I’m not sure.

    • February 1, 2016 at 9:58 am

      Hmm, interesting. I haven’t seen mangrove pit vipers climb trees to any height. One meter off the ground or water is as high as I’ve seen them. Doesn’t mean they don’t climb way up into a tree, so maybe it was that. They don’t tend to be so black though, unless it was a melanistic species with an abundance of dark pigment. What was the general shape and size? 1 meter long? Long tapered tail, or just rather thick and pudgy like a viper?

  • November 21, 2016 at 10:08 am

    I was lucky enough to see one in Singapore yesterday. Blood on its cheek and its tail, and a fresh bulge in its mid-section. Consequently it was placid and loathe to move about. You can use the photo if you like :D

  • November 20, 2017 at 8:40 am

    I am living in koh phi phi, and last night my neighbour killed two of them, one in his house and one outside!
    I Have a picture but could not find out how to upload here!

  • November 8, 2018 at 6:43 am

    Are they found on the ground or do they live more in the trees?

    • January 6, 2019 at 10:54 am

      I’ve seen them in both habitat


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