Annulated Sea Snake
Hydrophis cyanocinctus
A widespread, boldly banded sea snake with alternating dark and pale rings, common in shallow coastal and estuarine waters across Asia.
- Venomous?
- Venomous
- Adult length
- 1.2-2.2 m (4-7.2 ft)
- Range
- Indo-Pacific coastal waters from the Persian Gulf to Japan
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Overview
The annulated sea snake, sometimes called the blue-banded sea snake, is a common and widely distributed marine elapid found from the Persian Gulf to the coasts of China and Japan. Its striking black-and-pale banding makes it one of the more recognizable sea snakes.
It possesses potent venom used to immobilize fish prey. While capable of a serious bite, it is generally non-aggressive and tends to avoid contact with people.
How to identify it
- Long, moderately slender body with a paddle-shaped tail
- Bold pattern of dark bluish-black bands or rings alternating with pale gray or yellowish interspaces
- Bands typically wider on the back, narrowing toward the belly
- Small head, not much wider than the neck
- Smooth scales
- Adults commonly 1.2-2.2 m
Habitat & range
Occupies shallow coastal waters, estuaries, and river mouths over sand or mud substrates. One of the most widely ranging sea snakes, found from the Persian Gulf across the Indian subcontinent, Southeast Asia, and up to China, Korea, and Japan.
Behavior, diet & reproduction
Feeds mainly on fish, particularly eels and gobies, hunting along the bottom or among crevices. Active at various times of day. Reproduction is ovoviviparous, with females bearing live young in the water, typically several per litter.
Frequently asked questions
Is the annulated sea snake venomous?
Yes, it has potent neurotoxic venom, though it is not aggressive toward humans.
How can you identify it?
By its bold black or dark blue bands alternating with pale interspaces along a long, slender body.
Where is it found?
Widely across the Indo-Pacific, from the Persian Gulf to Japan and Korea.
What does it eat?
Mainly fish, especially eels and gobies found near the seafloor.
Annulated Sea Snake guides
In-depth guides for identifying and understanding Annulated Sea Snake.
