Apart from the infamous sharks, sea snakes are probably people’s worst nightmares when swimming, diving or snorkeling. And rightly so.
Sea snakes are among the most venomous animals on Earth. Beaked sea snakes, in particular, are more aggressive than the rest of the sea snake species.
They use their venom for hunting, but fortunately, attacks on people are sporadic, as you’ll see, although they’re responsible for the vast majority of deaths from sea snake bites. Up to 90% of all sea snake bites come from our beaked sea snake friend! Read more on their venom below.
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What is the scientific name of a beaked sea snake?
Commonly known as the beaked sea snake, its actual scientific name is Enhydrina schistosa. Its other common names include hook-nosed sea snake, common sea snake, or the valakadyn sea snake.
The name valakadyn is from the Malayalam and Tamil word Vala kadiyan, meaning net biter and beaked comes from their deep notch between the two halves of their lower jaws, creating their distinguished “beaked snouts” look.
This Asian sea snake has a doppelganger from Australia. Two scientists from the University of Queensland and Adelaide, respectively, discovered that the Asian individuals belong to a completely different branch of the sea snake family tree than the Australian ones.
They are two species, which have evolved to look so identical that everyone thought they were the same until now. The Asian Enhydrina schistosa got to keep its name while its Australian counterpart got the name of Enhydrina zweifeli.
What is the size and the lifespan of a beaked sea snake?
The shape of the beaked sea snake’s body is very flattened, with the tail like an oar, allowing them to move through the water easily.
Beaked snakes are easily distinguished from all other sea snakes by an extremely long and narrow mental scale that is largely concealed in a deep notch between the lower jaws.
The species is reported to grow to a maximum length of 140 cm (4.6 ft), while the range is between 40.0 and 118.2 cm (1.3 – 4 ft). I’ve seen reports that sea snakes live to be around ten years old in the wild but couldn’t confirm it anywhere else.
Where do beaked sea snakes live?
Beaked sea snakes are found throughout Asia and Australasia but generally along the coast of India, where they are the most common of the 20 kinds of sea snakes found in that region. They mostly inhabit the mud and sand environments in estuaries, harbors, and shallow bays.
All the sea snakes in India are protected under the Indian Wildlife Protection Act 1972.
How do beaked sea snakes behave?
Why would a snake have a beak? Smart folks think that this notch helps them widen their jaws further than other sea snakes and swallow their favorite prey, spiny catfish and pufferfish. Mhmm, tasty.
Unlike most of the other sea snakes that are very easy-going, almost mellow, and rarely aggressive, the beaked sea snake has a reputation for being aggressive.
Sea snakes are reptiles just like land snakes, and they have lungs and need to breathe air just like people. So a sea snake must head to the surface every once in a while for a breath.
Sea snakes have a huge lung that takes up nearly the entire length of their bodies, so they can hold a big breath that will last a while.
Each time a sea snake surfaces, it usually spends a minute or two resting and breathing before gulping in that last big breath and diving back down to the reef.
A breath can last 1-2 hours depending on the species, but most sea snakes breathe more often than that unless they are sleeping.
They can also absorb a little bit of oxygen from the water directly through their skin, which helps them extend their dives.
Do sea snakes sleep? Just like their land buddies, sea snakes do sleep. They sleep on the bottom of the sea or a reef. You can even pet them but maybe stay away from our beaked friend, because as we’ve learned, he can be a bit of an ass.
Beaked sea snake bears 4-9 young each time, but as the mortality rate is too high, relatively few young survive to reach the adult stage. The young snakes reach maturity at the age of three years.
True sea snakes never voluntarily leave the water, although sea kraits come out of the water on land to court, rest, digest their
There’s not much information if the beaked sea snake goes out on land. Some photos did surface of these snakes chilling on the ground probably because basking in the sun helps to increase the metabolic rate to accelerate the digestion process, or to facilitate the growth of eggs.
What do sea snakes eat?
Sea snakes hunt for fish. They have an incredibly potent neurotoxin, and beaked sea snakes have been found to feed at night, eating crustaceans and fish actively.
When a sea snake hunts, it takes advantage of having a small head and a thin body to go from hole to hole in the reef, poking its head inside. It hopes to corner a fish or invertebrate that’s hiding in the hole. Once the hunting starts, more sea snakes start coming into the reef to join the hunt.
All it needs to do is tag a fish with the small, fixed fangs inside of its mouth, and immediately the fish becomes paralyzed, and then the snake is capable of having its meal.
The beaked sea snakes always ingest the head portion of the prey ﬁrst.
How deadly is the beaked sea snake?
Beaked sea snake’s venom comprises highly potent neurotoxins and myotoxins and is more potent than the venom of a cobra or a rattlesnake.
The median lethal dose (LD50) value is 0.1125 mg/kg based on toxicology studies, and the average venom yield per bite is approximately 7.9–9.0 mg, while about 1.5 milligrams of venom of beaded sea snake is rated four to eight times as toxic as cobra venom and it can cause death to humans. Yup, one bite can kill you many times over!
I’ve already mentioned that one of their common names is the valakadyn sea snake. Valakadyn meaning the net biter. Why net biter? Well, they’ll often get tangled in fishing nets, and subsequently, unwary fishermen get bitten and injected with their deadly venom. It’s no surprise then that most deaths and injuries from sea snakes come from our beaked fella.
Then again, it’s not their fault that humans use fishing nets, and among all the fishing methods, bottom trawling, which involves dragging a large net across the seafloor, is the most destructive to our oceans.
Though, to be fair, most of the bites probably occur to fishermen while using manual shrimp trawls (nets).
The typical symptoms of sea snake bites begin within three hours. They can include painful muscles, paralysis, joint aches (arthralgia), blurry vision, difficulty swallowing or speaking, excessive saliva production, vomiting, droopy eyelids (ptosis). If there are no symptoms within eight hours, then venom injection is very unlikely.
The amount of venom injected (if any) cannot be predicted, so any suspected bite by a sea snake should be considered potentially life-threatening, and the person bitten should seek immediate medical attention.
There is no benefit to suctioning or cutting the bite area to “suck the venom out.” The overall death rate is 3% for victims bitten by sea snakes, and in cases where there is “severe” envenomation, the rate is 25%.
There is anti-venom available and should be started as soon as possible when a health care professional determines it is needed. It is most effective if given within 8 hours of the sea snake bite.
Sea snake’s venom has proved to be a source of potential antibiotics agents against human pathogenic diseases like the common cold, flu, meningitis, measles, chickenpox, oral and genital herpes, warts, viral gastroenteritis, including norovirus and rotavirus…
What are major threats to sea snakes?
Major threats to sea snake populations come from them being entangled during trawling operations, and these snakes are exploited for their venom and skin in many East Asian countries.
I’ll leave you with this intriguing and concerning National Geographic video. At 80 tons of sea snakes being removed annually from the Gulf of Thailand and shipped domestically and internationally to be eaten, it is one of the largest marine reptiles exploitation in the world.
These highly venomous snakes may end up in shoots of drinks, or they can end up as traditional medicine. You might be shocked to see the sea snake traders actually step into a pool of highly venomous snakes barefoot and barehanded. I guess people would do anything for a bit of the pie (or a crumb).