Tag Archives: dangerous Thailand snake

Red Necked Keelback – Venomous – Dangerous

Red Necked Keelback Snake, venomous, Thailand and southeast Asia.
A beautiful snake, usually under 1 meter, not very aggressive. ©2009 ThailandSnakes.com.

(Page Updated: 16 May 2017)

Rhabdophis subminiatus (Red-Necked Keelback Snake)

Thai: (ngoo lay sab ko dang)

Length: Up to 130 cm (1.3 meters). Usually under 1 meter.

Range: Thailand and southeast Asia.

Notes: These snakes are commonly found near water, lakes, ponds, and in gardens. Recently a friend had one in his swimming pool in Krabi town, southern Thailand.

Active Time? Daylight hours. I’ve found them sleeping around 1 foot off the ground in bushes.

Food: Frogs, poisonous toads, and fish. I have not seen them eat anything but frogs and toads.

Defensive Behavior: Spread out the neck slightly to make themselves appear bigger. Not as dramatic as a cobra. Lift their head and neck off the ground 4-5 inches.

Some snakes of this species, and others in the genus Rhabdophis, have displayed a rather unique defensive behavior of exposing the back of their neck and secreting poison from their nuchal glands. This is not all that common unless very provoked.

One researcher, Kevin Messenger, claims that the R. subminiatus helleri he caught in Hong Kong actually sprayed a mist of the poison into the air from the back of the neck. Quite amazing, if true, right? Obviously more study is needed into the secret life of this fascinating snake. Other snakes in Rhabdophis genus with nuchal glands: R. nuchalis, R. tigrinus, R. nigrocinctus, and R. chrysargos (in Thailand).

Here is an image of the snake expressing poison from the nuchal glands.

Nuchal gland poison from Rhabdophis subminiatus helleri
The liquid on the neck near the top of the red shade is poison acquired at least in part, from eating poisonous Bufo toads.

Here is the description in a scientific journal about Kevin’s encounter.

Venom Toxicity: LD50 is 1.29 mg/kg for intravenous injection (source). That is about the same rating as the very deadly “Banded Krait (Bungarus fasciatus)”. It was previously thought these snakes were harmless. Some kept them as pets and were bitten. In one case the snake was left to bite for two entire minutes before removing it from a finger.

Serious complications resulted requiring hospitalization and intensive care. Click for article. These snakes are rear-fanged and need to bite and hold on, or, repeatedly bite to have any effect on humans. Once they do either – there is the possibility of severe problems including renal failure and death. Recently a small boy of 12 years old was bitten by one he was keeping as a pet in Phuket, Thailand and he is currently being treated (11/5/10). Be very careful not be be bitten by these snakes. There is NO ANTIVENIN available yet for these snakes in Thailand. Scroll down for information about antivenin manufactured in Japan that may have some positive effect.

Another study in Japan ranked the venom as having an LD50 of 1.25 mg/kg for intravenous injection. (Japan Snake Institute, Hon-machi, Yabuzuka, Nitta-gun, Gunma-ken, Japan) V.1- 1969- Volume(issue)

In Japan they make limited amounts of antivenin, but it is specifically for their in-country use.

One WHO (World Health Organization) publication about the management of venomous snake bites in Southeast Asia mentions the antivenin for Rhabdophis tigrinus in Japan as having some effect on the venom of R. subminiatus. I am not sure if this is strictly for R. subminiatus found in Japan, or not. Worth a try though if you can get them to send you some antivenin. Otherwise, there is no other option – there is no monovalent antivenin specifically for R. subminiatus.

Japan Snake Institute
Nihon Hebizoku Gakujutsu Kenkyujo
3318 Yunoiri Yabuzuka
Yabuzukahonmachi Nittagun Gunmaken 379-2301
Tel 0277 785193 Fax 0277 785520
[email protected]
www.sunfield.ne.jp/~snake-c/
Yamakagashi (Rhabdophis tigrinus) antivenom. Also effective against rednecked keelback (R. subminiatus venom)

Update: The 12 year old boy bitten by the Rhabdophis subminiatus was treated for 2 weeks of intensive care, and released. He was bitten multiple times, the 2nd bite lasting over 20 seconds.

Offspring: I had a juvenile red-necked keelback I’ve taken photos and videos of and released into the wild. I cannot find anything much about offspring. Recently (mid-June) I found a DOR juvenile very recently hatched, so like most snakes in Thailand the time around June is when they are hatching out. The coloration of the juvenile is quite different from adults as you can see in the photo and video below.

Rhabdophis subminiatus Juvenile
A hint of red on the neck in the juvenile. A pronounced black banding at the neck and grey on the head is evident in juveniles.

Notes: These snakes can inflict a deadly bite when they are allowed to bite for longer than a couple of seconds. I know personally of two instances where a child was bitten for well over 20 seconds, and a man was bitten for about a minute. Neither wanted to hurt the snake to remove it forcibly, and both spent over a week in intensive care, with the possibility of renal failure and death. Do not play with these snakes. If you have one, do not free-handle it. Treat it like you would a pit viper or a cobra. The LD50 on this snake for intravenous was stated to be 1.29 mg/kg. That is VERY venomous.

As a precaution, any snake in the Rhabdophis genus should be treated with extreme caution. In Thailand we also have the diurnal Rhabdophis nigrocinctus, and Rhabdophis chrysargos, both of which may be able to inflict a medically significant bite if given the opportunity.

Red-necked Keelback Scientific Classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Genus: Rhabdophis
Species: Rhabdophis subminiatus

Video – Red-necked Keelback

Video – Red Neck Keelback Snake ( <- click) video

Thailand Snake Note – Deadliest Snake in Thailand?

Depending how you define ‘deadliest’ there could be a few different Thailand snakes to get that title.

If you’re defining deadliest snake as the one that actually kills the most people in Thailand per year, then the deadliest snake is the Malayan Pit Viper. These small brown vipers lay in the grass and wait for prey to walk by. They are lazy to move if they sense human footsteps coming their way. This means that they bite a lot of people. Some either don’t have the money to go to the hospital, don’t go for some other reason, or literally cannot get to a hospital – and they die as a result of complications from the venom in the bite.

If you are defining deadliest as the snake with the most toxic or potent venom, then the Malayan Krait (Blue Krait) would get that title. Just a tiny amount of venom can kill you from a krait.

If you are defining deadliest as the snake that can kill you fastest – well it’s probably the King Cobra’s bite, which can inject 7ml of venom into your body – enough to kill an elephant – and it has done just that before too.

The deadliest snake in the world – the one that kills more people than any other snake on the planet is not the mamba, it’s not the inland taipan, it’s not the Naja (cobra), or krait. It’s the Russell’s Viper. Thailand also has the Russell’s Viper, and they are fairly common in central Thailand, but they are not located in the southern provinces at all. The Russell’s Viper has a very deep bite and it can transfer a good deal of highly toxic venom.