Elapidae
Brown-lined Sea Snake
Aipysurus tenuis
A slender sea snake described with a light-brown body, darker lengthwise markings and bars along the sides. Records place it in waters off north-western Australia.
Dangerously venomous
Identification and appearance
A slender marine snake recorded in Western Australian and Arafura Sea taxon records. Its light-brown body has darker longitudinal lines, flank bars and a dark-brown upper head in the Western Australian Museum description.
Other names
Arafura Sea Snake, Mjoberg’s Sea Snake
Typical length
Published size figures differ: AROD lists a 130 cm average, while the older WA Museum account gives an upper length of 102 cm. No typical adult interval or current maximum is used here.
Body build
slender
Head appearance
dark-brown upper head
Key identification features
- Slender marine snake
- Light-brown body with darker scale-tip lines and flank bars
- Marine range rather than a mainland habitat
Where it is found
Marine waters off north-western Western Australia and the Arafura Sea; exact state-level limits remain unresolved.
Habitat
Associated with soft-bottomed coastal habitats off Western Australia.
Medical significance
A bite may cause serious envenoming. Treat any suspected bite as an emergency, call 000 and do not wait for identification.
What to do if you encounter one
Give sea snakes space in the water and on shore. Do not touch, catch or approach one for a closer photograph.
Taxonomy notes
Brown-lined Sea Snake and Mjoberg's Sea Snake are both used as common names.
Sources checked
- Atlas of Living Australia — Brown-lined Sea Snake (2026-09-25)
- Western Australian Museum — Sea Snakes of Western Australia (2026-09-25)
- CSIRO CAAB — Aipysurus tenuis (2026-09-25)
- The Reptile Database — Aipysurus tenuis (2026-09-25)
- ANZCOR — First Aid Management of Australian Snake Bite (2026-09-25)
- Nankivell and Sanders — Aipysurus population study (2026-09-26)
Still not sure?
Compare this snake with more clues.
A profile is a guide, not a reason to approach or handle a snake.