FaunaHub

Sea Snake (Laticauda colubrina)

ReptileSnakeMarine

Banded sea krait (Laticauda colubrina), a black-and-grey banded sea snake swimming on a reef.

Banded sea krait (Laticauda colubrina).

Image: Diego Delso, CC BY-SA 4.0, via Wikimedia Commons.

Overview

Sea snakes are venomous marine reptiles — members of the cobra family (Elapidae) — that have adapted superbly to life in the ocean, mostly in the warm waters of the Indian and Pacific Oceans. Their most obvious adaptation is a flattened, paddle-shaped tail that drives them through the water. The banded sea krait (Laticauda colubrina), shown here, is a beautifully banded example. True sea snakes spend their whole lives at sea, while sea kraits like this one come ashore to rest, digest, and lay eggs.

Sea snakes are highly venomous, but they are generally placid and rarely bite people; serious incidents are uncommon and usually involve handling or entanglement in nets.

Safety note: this is a general educational profile, not first-aid or medical guidance. Sea snakes are venomous and should never be handled; for any snakebite, seek professional medical care immediately.

Habitat & Range

Sea snakes live mainly in the tropical and subtropical Indian and Pacific Oceans, around coral reefs, coastal shallows, mangroves, and estuaries. True sea snakes are fully marine, while sea kraits divide their time between the sea — where they hunt — and nearby land or islands, where they rest and breed. They are absent from the Atlantic.

Diet

Sea snakes are carnivores that hunt underwater, mostly for fish and fish eggs; some specialise on eels, and the banded sea krait is a notable eel-hunter, probing reef crevices for its prey. They use venom to quickly subdue prey before swallowing it whole.

Behavior

Sea snakes are remarkably adapted to the sea: besides the paddle tail, they can absorb some oxygen through the skin, have a single greatly enlarged lung, and possess special glands to get rid of excess salt. They must surface to breathe but can dive for long periods. Sea kraits return to land to rest and lay eggs, whereas most true sea snakes give birth to live young at sea and never leave the water. Despite their potent venom, sea snakes are generally non-aggressive and curious rather than dangerous, biting people only rarely.

Human Interaction & Conservation

Sea snakes are a wonderful sight for divers, who usually find them calm and even inquisitive, but their venom means they should never be touched or provoked — most bites happen to fishers handling snakes caught in nets. Some sea snakes are hunted for skin and meat, and reef degradation affects them; status varies by species. This profile is educational only; for any bite, seek immediate professional medical care. Consult authoritative sources for species-specific status.

More photos of the sea snake

A sea snake gliding over coral, showing its paddle-like tail.

Banded sea krait (Laticauda colubrina).

Image: Diego Delso, CC BY-SA 4.0, via Wikimedia Commons.

Frequently Asked Questions — Sea Snake

Are sea snakes dangerous to people?
Sea snakes are highly venomous, but they are generally placid and rarely bite humans. Most encounters — including with divers — are harmless, and serious bites are uncommon, usually involving people handling snakes (for example, fishers untangling them from nets). The simple rule is never to touch or provoke a sea snake.
How are sea snakes adapted to ocean life?
In several remarkable ways: a flattened, paddle-shaped tail for swimming, the ability to absorb some oxygen through the skin, a single enlarged lung for long dives, and special glands to excrete the excess salt they take in. These adaptations let them live in the sea, surfacing only to breathe.
What's the difference between a sea snake and a sea krait?
Both are venomous marine elapids, but they differ in lifestyle. True sea snakes are fully aquatic, giving birth to live young at sea and rarely (if ever) coming ashore. Sea kraits, like the banded sea krait, are amphibious — they hunt in the sea but return to land to rest, digest, and lay eggs.
What do sea snakes eat?
Mostly fish and fish eggs, caught underwater. Some sea snakes specialise on particular prey — for instance, the banded sea krait hunts eels in reef crevices. They use venom to subdue prey quickly before swallowing it whole, the way other elapid snakes do on land.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.