Reptiles

Sea Krait

Laticauda · also called sea kraits, banded sea kraits

Least Concern → carnivore Ocean Coasts & shorelines

A sea krait carries some of the most potent venom of any snake and yet is one of the calmest, most approachable animals a diver can meet on a coral reef. It has not fully committed to the sea the way true sea snakes have: it still crawls onto island beaches to lay eggs, digest a meal, or shed its skin, a foothold on land that its more thoroughly marine relatives gave up long ago.

Overview

Sea kraits are the genus Laticauda, boldly black-and-white or black-and-blue banded snakes of Indo-Pacific coral reefs and rocky coasts. They hunt eels and eel-like fish, probing into reef crevices with a venomous bite strong enough to subdue prey that would otherwise be hard to extract from tight spaces.

Half sea snake, half land snake

Unlike fully marine sea snakes, a sea krait keeps the broad belly scales of a land snake alongside a flattened swimming tail, letting it crawl reasonably well on rocks and beaches. It comes ashore to lay eggs — something true sea snakes, which give birth live entirely at sea, never do — and also to rest, digest, and moult.

Potent venom, low real-world risk

Sea krait venom is extremely potent by weight, but the snakes are docile and reluctant to bite, and their small mouth and short fangs make an effective bite to a person difficult even when one does occur. Serious bites to divers are rare; most documented cases involve fishers handling snakes caught in nets.

Status

Least Concern — widespread and locally common across a vast area of Indo-Pacific reef and coastline, though some populations are collected for skin and meat in parts of Southeast Asia.

Sea Krait: common questions

Is a sea krait dangerous to divers and swimmers?

Sea kraits carry venom that is extremely potent by weight, among the most dangerous of any snake, but in practice they pose very little real-world danger to people because they are calm, slow-moving, and strongly reluctant to bite even when approached or briefly handled by experienced divers, and their small mouth and short fangs make it difficult for them to deliver an effective bite to a person unless grabbed and provoked at length. Documented serious bites to divers or swimmers are rare, and most recorded human bites and fatalities involve fishers handling sea kraits caught in nets rather than incidental encounters on a reef.

Why do sea kraits come ashore when most sea snakes never leave the water?

Sea kraits retain several physical features that true, fully marine sea snakes have lost over their evolutionary history, most importantly broad belly scales that still allow reasonably effective crawling on land, so coming ashore remains a practical option for them. They use this ability specifically to lay eggs, since unlike live-bearing true sea snakes they must deposit eggs in a stable, humid, land-based site to develop, and also to rest, digest large meals, and shed their skin, activities that may be easier to manage safely on land, sheltered in rock crevices, than while continuously swimming and diving at sea.

What do sea kraits eat, and how do they catch it?

Sea kraits specialise heavily on eels and other elongated, eel-like fish, which they hunt by swimming along a reef and probing their head and neck into crevices, holes, and rubble where such fish hide, a habitat and prey type that would be difficult for many other predators to access effectively. Once located, the prey is subdued with a venomous bite, since eels can be strong and difficult to swallow while still struggling, and the snake then works the elongated fish down headfirst, a process it may need to complete on land or in a sheltered spot given how long it can take.

How can you tell a sea krait from a true sea snake?

The clearest visual cue is the tail and the belly. A sea krait has a flattened, paddle-like tail for swimming but keeps wide, distinct belly scales similar to a land snake's, and it is boldly banded in contrasting dark and pale colours. A true sea snake typically has an even more strongly flattened, laterally compressed body overall, much reduced or almost absent belly scales that make it essentially unable to move on land, and it never voluntarily leaves the water, giving birth to live young entirely at sea rather than coming ashore to lay eggs the way a sea krait does.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published September 11, 2026. Last updated September 11, 2026.

Quick facts

Scientific name: Laticauda
Diet: Almost entirely eels and small eel-like fish hunted by probing into reef crevices, rubble, and burrows, along with occasional other small fish, using a strongly venomous bite to subdue prey that would otherwise be difficult to extract from tight coral or rock crevices
Half sea snake, half land snake: Sea kraits are unusual among marine snakes for keeping a genuinely amphibious lifestyle, with a flattened, paddle-like tail well suited to swimming but retaining the broad belly scales of a land snake, which let them crawl reasonably well on rocks and beaches, unlike fully marine sea snakes that have lost this ability almost entirely
Coming ashore to lay eggs: Unlike true sea snakes, which give birth to live young entirely at sea, sea kraits return to land, often the same island beaches and rock crevices year after year, to lay clutches of eggs in a hidden, humid site, making them one of the only marine snakes that still depends on dry land to reproduce
A bold black-and-white or black-and-blue pattern: Sea kraits are marked with a series of bold, contrasting dark bands around a pale body, typically black on bluish grey or white, a striking pattern that stands out clearly both underwater and when the snake is resting or basking on rocks
Highly venomous but rarely aggressive: Sea krait venom is powerful, among the most potent of any snake by weight, capable of causing serious paralysis, but the snakes are generally slow-moving, docile, and reluctant to bite, and divers who encounter sea kraits on reefs are very rarely bitten unless the animal is grabbed or cornered
A small mouth limits the real-world risk: Despite the strength of its venom, a sea krait has a small mouth and short fangs adapted for gripping slender eels rather than for a wide gape, so even when a bite does occur it often fails to penetrate human skin deeply enough to inject a dangerous dose, which helps explain why documented serious bites to people are uncommon
A digestive and moulting refuge: Sea kraits also come ashore periodically simply to rest, digest a large meal, and shed their skin, activities that are apparently easier or safer to carry out on land than continuously at sea, and they can be found coiled in rock crevices, under vegetation, or in small caves near the shoreline during the day
Range: Warm coastal waters of the Indian and Pacific Oceans, from the east coast of Africa and the Red Sea across South and Southeast Asia to Australia, Japan, and many Pacific islands, on coral reefs, rocky coastlines, and inshore waters, coming ashore on nearby beaches, rocky islets, and coastal vegetation to rest, digest, moult, mate, and lay eggs.
Conservation status: Least Concern → ≈ Most sea krait species remain widespread and locally common across their Indo-Pacific range and are assessed as Least Concern, benefiting from access to both marine feeding grounds and terrestrial refuges across a very large number of islands and reef systems. Because they depend on undisturbed island beaches and rock crevices for egg-laying, resting, and moulting, sea kraits can be affected locally by coastal development, tourism disturbance, and the harvesting of adults for skin and meat in parts of Southeast Asia and the Philippines, where sea kraits are collected in some numbers, but no species is currently considered globally threatened in the wild