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sea snake

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Sea Serpent One

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Sea snakes are extremely poisonous, even more powerful than cobras!

There are more than 60 species of sea snakes that belong to the same family as cobras, the cobra family . They are highly venomous and fall into two groups.

First of all, true sea snakes belong to the subfamily Pelidae . Also, they are related to the Australian terrestrial cobra. The second group is sea snakes, which belong to the subfamily Laticaudinae and are closely related to Asian cobras.

Sea snakes are venomous, and their venom is very potent; however, if they do bite, death is rare due to the short venom output of their fangs.

There are 55 species of true sea snakes, typically ranging in length from 3.2 to 5 feet, although some individuals can grow as large as 8 feet.

To adapt to their surroundings, sea snakes have flattened bodies and short, paddle-like tails. Additionally, they have valved nostrils at the top of their noses, and their lungs run throughout their bodies.

Surprising Facts About Sea Snakes

The hook-nosed sea snake has a gray upper body, white or yellowish sides, and gray-blue stripes on the lower body.
Sea snakes have a long history, with the first species appearing in the Coral Triangle of Southeast Asia between 6 and 8 million years ago.

© iStock.com/Eagle2308

  • Sea snakes are ancient, the first species evolved between 6 and 8 million years ago in the Coral Triangle of Southeast Asia
  • These sea snakes are the only reptiles to give birth in the ocean
  • sea snakes die of thirst
  • They are highly venomous, but a bite from them is rarely fatal because their tiny fangs either cannot penetrate the skin through wetsuits or do not produce enough venom.
  • There are 69 species of sea snakes

While there are about 70 different species of sea snakes, here are some of the most common:

  • Hydrophis platurus (Yellow-bellied sea snake)
  • Hydrophis cyanocinctus (blue-banded sea snake)
  • Aipysurus duboisii (Dubois sea snake)
  • Laticauda colubrina (banded sea snake)
  • Hydrophis elegans (Elegant Sea Serpent)
  • Hydrophis belcheri (Belcher's sea snake)
  • Aipysurus eydouxii (Sting-bellied Sea Snake)
  • Hydrophis obscurus (spotted sea snake)
  • Aipysurus laevis (Olive sea snake)
  • Hydrophis melanocephalus (Black-headed sea snake)
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evolution and origin

Spotted Snake Eel
Between 2 and 16 million years ago, sea snakes in South Asia underwent significant evolution and diversification, resulting in the majority of modern sea snake species found in this region.


According to a recent study, there is no evidence of when, where or how often various species developed their color recognition abilities, such as sea snakes: they entered the marine environment 15 million years ago, and since then, in response to changing evolving with lighting conditions.

Most modern sea snakes evolved and diversified in this geographic region between about 2 and 16 million years ago, when the region was a sizeable network of wetlands linking Southeast Asia and the Australasian islands.

Additionally, the Coral Triangle in Southeast Asia is where the earliest sea snakes evolved, some 6 to 8 million years ago, although most species of sea snakes only evolved between 1 and 3 million years ago.

where to find sea snakes

Sea snakes are found in the coastal regions of the western Pacific and Indian Oceans, from eastern Africa to the Gulf of Panama. However, some species live in the open ocean off the west coast of the Americas, such as the yellow-bellied sea snake.

But their preferred habitat is shallow water, no more than 100 feet (though they can go down to 300 feet), because they need to hunt on the sea floor between coral reefs. Also, some species prefer to hunt on soft bottoms consisting of mud, while others prefer hard bottoms, such as corals.

Some countries where you can find sea snakes include:

  • new Zealand
  • Peru
  • the Philippines
  • solomon islands
  • South Africa

Types of Elapids

Belcher sea snake
Sea snakes belong to the cobra family, which includes venomous snakes with upright, permanently protruding fangs.


The Elapidae or Elapids family are venomous snakes with permanent upright fangs, which includes sea snakes. Most species in this family respond to threats by rearing upwards and expanding their neck flaps. They prefer warm temperatures and can be found in tropical and subtropical regions around the world. Cobras vary in size and are often neurotoxic. There are approximately 360 species and more than 170 subspecies in this family, including:


Cobras come in a variety of sizes and colors; some are yellow, black, red, banded, or mottled. They are usually large snakes, many over 6 feet. The largest true cobra is known as the forest cobra and is 10 feet long. Additionally, Ashe's spitting cobra is the largest spitting cobra, reaching a length of 9 feet.

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On the other hand, the smallest species is the Mozambique cobra, which can reach 4 feet long when fully grown.

Finally, the king cobra lives up to its name, being the longest of all venomous snakes at 18 feet long!


Mamba snakes occur in rocky hills and savannas in eastern and southern Africa. They hold the title of Africa's longest venomous snake, reaching up to 14 feet when fully grown. Plus, they're super fast, traveling up to 12.5 miles per hour.

tiger snake

Tiger snakes get their name from the tiger-like stripes on their bodies, but not all snakes have a striped pattern.

Getting bitten by a tiger snake is very dangerous as they are one of the most venomous snakes on the planet and its fangs measure between 0.14 and 0.20 inches.

They are great swimmers and glide through the water with ease. When threatened, a tiger snake will stand upright and lower its head, similar to a cobra.

scientific name

The scientific name of sea snakes is Hydrophiinae , which belongs to the cobra family. Furthermore, sea snakes belong to the class of reptiles . Most sea snakes fall into this category, but they are not the only ones. It also includes many species of venomous snakes such as:

  • Taipan
  • tiger snake
  • brown snake
  • death viper

Population and Conservation Status

Banded sea snake swimming underwater in a coral reef
Due to the wide variety of sea snake species, determining their population size and overall conservation status is challenging.

©Rich Carey/Shutterstock.com

Because of the wide variety of species of sea snakes, it is difficult to generalize their population size and conservation status. However, several sea snakes are listed as endangered on the IUCN Red List.

For example, the dusky sea snake is shown as endangered, while the Crocker's sea snake is listed as vulnerable. Sadly, two species are listed as critically endangered: the short-nosed and leaf-scaled sea snakes.

appearance and description

Sea snakes come in all sizes and colors. However, most of them are between 4 and 5 feet long and often have a distinct ring pattern.

Similar to most snakes, they are long and slender, but their tails are unique in that they are flattened with paddle-like tips that aid in swimming.

Laticauda laticaudata blue-banded sea snake
Sea snakes come in a variety of colors, and they often have different ring patterns, like this blue-banded sea snake.

© Bramadi Arya/CC BY-SA 4.0 – License

Reproduction and Lifespan

Sea snakes are usually oviparous, except for one genus, the krait, which is oviparous and includes five species that lay eggs on land. Ovoviviparous is when the eggs are kept in the uterus until they hatch.

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Females give birth to live pups, usually large (sometimes half the length of the mother). Generally, sea snakes can live for about ten years.

Venoms: How Dangerous Are They?

The largest sea snake that ever existed could eat a small whale

© Nobu Tamura (http://spinops.blogspot.ca/) / Creative Commons – Licensed

Sea snakes are extremely poisonous, even more powerful than cobras! Their venom is a deadly mixture of myotoxins and neurotoxins. Fortunately, there are not many records of sea snake bites, and those who were bitten survived. Due to their small fangs, sea snakes rarely release venom when attacking.

Sometimes the bite is painless and there are no symptoms. However, some small teeth may remain in the wound.

However, when symptoms appear, it takes 30 minutes to several hours. They can include:

  • Thirsty
  • Headache
  • Vomit
  • rigidity
  • sweating
  • Muscle pain
  • tongue swelling

Eventually, muscle degeneration and paralysis set in, which can be fatal if the poison starts affecting the muscles involved in swallowing and breathing. Unfortunately, finding antivenom is nearly impossible because sea snake bites are rare.

Behavior and Humans

Sea snakes are extremely cautious animals, preferring to flee from danger.


Sea snakes are very timid creatures, preferring to back down from danger. They are the exact opposite of cobras in terms of aggressiveness, even though they belong to the same family.

Humans feed on sea snakes, which are often exploited for their meat, guts and skin. Unfortunately, sea snakes are still not protected by CITES despite their frequent capture in large numbers.

The Philippines is one of the biggest culprits, as sea snake meat has been used commercially since 1934. Ultimately, it is necessary to implement local protection to avoid overexploitation.

Other countries developing sea snakes are:

  • Australia
  • Taiwan Province of China
  • Japan
  • Thailand
  • Vietnam

Australia has since implemented special permits for fishing sea snakes; however, many areas where they occur are not controlled by the government and cannot be monitored 24/7.

But their biggest threats are climate change, low reproductive rates and bycatch, factors that are killing their numbers.

They have many predators, so they need to be vigilant from above and below at all times. These predators include:

  • shark
  • eel
  • sea eagle
  • big bony fish

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Sea snakes can swim at speeds of 2 – 2.5 mph.

Sea snakes are extremely poisonous, even more powerful than cobras! Their venom is a deadly mixture of myotoxins and neurotoxins.

Sea snakes typically prey on fish, eels, and fish eggs.

Sea snakes come in all sizes and colors. However, most of them are between 4 and 5 feet long and often have a distinct ring pattern.

Yes, however, sea snakes rarely release venom when attacking due to their small fangs.