Slender Sea Snake
Hydrophis gracilis
A slim-bodied sea snake found in tropical Indo-Pacific waters, with a tiny head and greatly elongated, thin forebody.
- Venomous?
- Venomous
- Adult length
- 1-1.4 m (3.3-4.6 ft)
- Range
- Coastal waters of the Indo-Pacific, including northern Australia and Papua New Guinea
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Overview
The slender sea snake is a moderately sized member of the diverse Hydrophis group, notable for its very thin, elongated forebody and disproportionately small head. It is found in warm coastal waters across much of the Indo-Pacific, including northern Australia and New Guinea.
As with many sea snakes in this region, it is regularly encountered as bycatch in prawn trawl fisheries, which has contributed most of the available population and distribution data.
How to identify it
- Extremely slender, elongated forebody with a tiny head
- Alternating dark and pale bands along the length of the body
- Rear of the body noticeably thicker than the thin neck region
- Compressed, paddle-shaped tail for swimming
- Body slenderness and small head are key features separating it from stouter banded sea snakes
Habitat & range
Occurs in shallow tropical coastal waters, often over soft or sandy substrates, across the Indo-Pacific including northern Australia and southern Papua New Guinea. Frequently found in areas also used by commercial shrimp trawling.
Behavior, diet & reproduction
Feeds mainly on eels and other slender, burrowing fish, probing soft sediment with its small head. Fully aquatic and rarely comes near shore. Gives birth to live young in the water, as typical for Hydrophis sea snakes.
Frequently asked questions
Is the slender sea snake dangerous?
It is venomous but not aggressive, and bites to humans are very rare.
Where is it found?
In tropical coastal waters across the Indo-Pacific, including off northern Australia and Papua New Guinea.
How can you identify it?
By its notably slender, elongated forebody, tiny head, and alternating dark and pale bands.
What does it eat?
Mainly eels and slender bottom-dwelling fish, hunted along sandy or muddy seafloor habitats.
Slender Sea Snake guides
In-depth guides for identifying and understanding Slender Sea Snake.
