Sea Snake
Hydrophis major
A fully marine elapid adapted for life at sea, with a paddle-like tail and no need to return to land.
- Venomous?
- Venomous
- Adult length
- 1.0-1.5 m (3.3-5 ft)
- Range
- Indo-Pacific coastal and offshore waters
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Overview
True sea snakes, exemplified by species such as the greater sea snake, are fully aquatic elapids that spend their entire lives in the ocean, having lost the ventral scales needed for movement on land. They are highly adapted to marine life, giving birth to live young at sea.
Widespread across the tropical Indo-Pacific, true sea snakes are important reef and coastal predators, though their venom, among the most potent of any snake, is rarely directed at humans.
How to identify it
- Laterally flattened, paddle-shaped tail adapted for swimming
- Cylindrical, muscular body with reduced or absent wide ventral scales
- Coloration often olive, gray, or brownish, sometimes with faint banding
- Nostrils positioned on top of the snout with valve-like closures for diving
- Distinguished from sea kraits by the paddle tail, lack of banding in many species, and inability to move effectively on land
Habitat & range
Inhabits shallow coastal waters, coral reefs, seagrass beds, and estuaries throughout the tropical and subtropical Indo-Pacific, occasionally found far offshore.
Behavior, diet & reproduction
Fully aquatic, surfacing periodically to breathe but capable of extended dives. Feeds mainly on fish and fish eggs, foraging along the seafloor and reef structures. Gives birth to live young entirely at sea, never coming ashore. Generally non-aggressive toward humans despite potent venom.
Frequently asked questions
Can true sea snakes come on land?
No, they are fully adapted to marine life and cannot move effectively on land, unlike sea kraits.
How venomous are sea snakes?
Their venom is extremely potent, among the most toxic of any snake, though bites on humans are rare and often deliver little venom.
What do sea snakes eat?
Primarily fish and fish eggs, foraged along reefs and the seafloor.
How do sea snakes reproduce?
Most true sea snakes give birth to live young directly in the water.
Sea Snake guides
In-depth guides for identifying and understanding Sea Snake.
