Belcher’s Sea Snake Species Profile (Information Hub)

You can find Belcher’s sea snake all around Malaysia, Indonesia, the Philippines, and on the south coast of Vietnam. Scientists aren’t sure of how big their population is, which is why they’re listed on the IUCD Red List as ‘Data Deficient,’ rather than vulnerable, endangered, or of ‘least concern.’

Belcher’s sea snake was named after Sir Edward Belcher, a British naval officer and explorer from the 1800s. The snake was first discovered by a botanist called John Edward Gray.

Aside from their common name, they go by a few others. Their scientific name is ‘Hydrophis belcheri.’ Hydrophis is the name for the family of sea snakes that live in the western and southern Pacific Ocean, whereas ‘belcheri’ comes from ‘Belcher.’

Belcher’s Sea Snake Identification

In terms of appearance, Belcher’s sea snake isn’t very distinctive:

  • It’s covered from top to tail in low-contrast bands. It’s a dull yellow color with green bands across its back, from top to tail.
  • It’s a medium-sized snake, only reaching 40 inches.
  • Its head is quite short and narrow too. This is unlike many other venomous snakes, which have large heads for their body, so that they can store lots of venom in their venom glands. Its head is the same color as the rest of its body.
  • It has a flat tail, which it uses like a scuba diver’s flipper to paddle itself along. This helps it to move more quickly underwater.

They’re often confused for the ‘yellow-lipped sea krait’ or ‘Hydrophis pachyceros.’ These snakes share similar habitats and are of the same family.

Belcher’s Sea Snake Habitat

Belcher’s sea snakes live in ‘marine neritic’ habitat. This means that they live in the ocean, but not out at sea. They stay in shallow areas by the coast.

That’s because they can only hunt for prey in shallow water where it can’t get away as easily. They only live in southeast Asia.

In that area of the world, shallow waters are often coral reefs. This part of the ocean is teeming with life, including tropical fish, regular fish, sea turtles, sharks, and more.

It’s the ideal place for a predator like Belcher’s sea snake to live, because there is so much food and so many places for them to hunt.

How Deadly Is The Belcher’s Sea Snake?

Belcher’s sea snakes are timid. They would rather get away from you than attack. On the other hand, when they do bite, their venom is highly toxic.

Figuring out which is the ‘world’s most deadly snake’ is complicated. The toxicity of the venom has to be taken into account. But aside from that, there are other factors that need to be assessed:

  • The amount of venom that the snake uses per bite
  • The amount of people the snake kills in the real world
  • How fast-acting the venom is
  • Whether the snake can inject the venom intravenously, i.e., in the vein. If it can, the venom is much more fast-acting and deadly
  • Whether there’s an antivenom available
  • How aggressive the snake is, i.e. how likely it is to bite you
  • Whether it envenomates every time it strikes

Belcher’s sea snakes are deadly. Their venom is very toxic indeed. And because it’s a sea snake, they can attack you when you least suspect it.

Venom Toxicity

Belcher’s sea snake venom is lethal, but scientists aren’t exactly sure how toxic it is. It has an LD50 of about 0.25mg/kg, which would make it one of the deadliest snakes in the world in that regard.

According to Toxicon, scientists had trouble extracting any venom from Belcher sea snakes because they produced so little.

They’re a small snake compared to the inland taipan or black mamba. They only produce a fraction of the venom that other, larger snakes do.

Fang Size

Belcher’s sea snake only has a tiny mouth. It’s already quite a short and thin snake, but its mouth is even proportionally for its size. This means that its fangs are actually quite short and small too.

Sea snakes have what are called ‘proteroglyphous’ fangs. This means that their fangs are quite short and can’t be folded back into the mouth (like a rattlesnake’s fangs can). They’re like short hypodermic needles.

When they catch prey, they’ll hold onto it and don’t let it go until it’s fully envenomated. This is different from rattlesnakes and other common venomous U.S. snakes, which bite once and then let go.

They’ll then hunt after the prey, waiting until it becomes uncoordinated and close to death. Belcher’s sea snakes progressively envenomate their prey by holding on for longer.

This is why most bites to humans aren’t using the full amount of venom. Because their fangs are so small, this makes it difficult for them to bite humans. Somebody diving in the ocean is usually wearing a scuba suit of some kind. This is hard for them to get their fangs into.

Besides that, because their jaws are quite small, they can’t easily bite a leg or arm. They simply can’t open their mouth wide enough.

Venom Effects

Immediately after the snake bites you, you’re unlikely to experience any symptoms. That’s partly because you’re underwater. The cool water around you makes it more difficult for your skin to pick up on the sensation of being bitten, so you might not even notice at first.

However, once it takes hold, it’s deadly. Belcher sea snake venom contains ‘postsynaptic neurotoxins.’ While not much is known specifically about Belcher sea snake venom specifically, postsynaptic neurotoxins all have a similar effect. The venom attacks the nervous system.

It prevents your nerves from being able to communicate with your body. Your brain is sending signals to your body all the time, whether it’s to do something you want your hands or arms to do (like writing or waving) or something that your body does without you thinking (like breathing).

How Many Deaths Does The Belcher’s Sea Snake Cause?

If a Belcher’s sea snake was to bite you, you’d almost certainly die if you didn’t have any antivenom immediately available. It takes around 30 minutes from the time that you’re bitten until you die.

There are a total of 70 sea snake species. But even if you count all species, it’s still very rare for anybody to be bitten and killed by sea snakes. According to the BBC, there’s just 1 recorded death. He was a fisherman working on a trawler, and the species of sea snake wasn’t identified.

Can You Survive a Sea Snake Bite?

Antivenoms have been created for most common venomous snake bites, and Belcher’s sea snake antivenom is available.

It’s manufactured by a biotech company called CSL Limited in Australia (antivenom code MAuCSL03). This antivenom works for all sea snakes in the same family (Elapidae) around Australia and Southeast Asia.

The only caveat is that if you’re out at sea and you’re bitten by one, it will be hard to get treated in time. That’s because the venom is so fast-acting, it can take little more than half an hour to kill you.

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Lou Carter

Hi, I'm Lou. I’ve always been fascinated by snakes and reptiles. That’s why I set up – to answer every question that you could ever have about snakes as pets (and how they survive in the wild.) I hope that you find this website useful!

Cite this article:

MLA Style: Carter, Lou. "Belcher’s Sea Snake Species Profile (Information Hub)" Snakes For Pets, (December 15, 2020),

APA Style: Carter, L. (December 15, 2020). Belcher’s Sea Snake Species Profile (Information Hub). Snakes For Pets. Retrieved December 15, 2020, from

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