Collected at Wickham Point, Northern Territory. Black-and-white journal photograph; whether the specimen was live or preserved when photographed is not stated. This image cannot show its living colour.
Elapidae
Arafura Smooth Sea Snake
Parahydrophis mertoni
A little-known venomous sea snake recorded in northern Australian coastal waters, including mangrove estuaries around Darwin.
Venomous
Identification and appearance
The head and body are nearly cylindrical. A study of Australian specimens found smooth body scales without the roughened texture seen in some other sea snakes. These features are not enough for a confident field identification.
Other names
Northern Mangrove Sea Snake, Merton's Sea Snake
Typical length
The field study reported an average total length of 50.1 cm for mature specimens and an apparent maximum of 57 cm. These figures came from a limited specimen sample, not a complete adult size range.
Key identification features
- Nearly cylindrical head and body
- Smooth body scales in the examined specimens
- Recorded in shallow mangrove-estuary waters
Where it is found
Documented specimens come from Darwin Harbour and other Northern Territory coastal localities. Broader accounts extend the range around the Arafura Basin and lower Gulf of Carpentaria; locality coverage remains incomplete.
Activity
A male was observed at night in shallow water over a tidal mudflat in Darwin Harbour.
Reproduction
Live-bearing; the field study examined a female carrying developed embryos.
Medical significance
Treat any suspected sea-snake bite as an emergency. Call 000 and follow Australian snakebite first aid; do not wait for identification.
What to do if you encounter one
Keep clear in mangroves, tidal flats or water and do not approach for a closer photograph.
Similar-looking snakes
Sea snakes can look alike; identification should be left to specialists.
Taxonomy notes
Originally described as Distira mertoni by Roux in 1910 and transferred to Parahydrophis in 1974.
Sources checked
- AROD — Northern mangrove snake (2026-09-26)
- Parkin & Schembri 2011 — Notes on the northern mangrove seasnake (2026-09-26)
- Roux 1910 record and current nomenclature — WoRMS (2026-09-26)
- Reptiles of Australia — Northern Mangrove Sea Snake (2026-09-26)
- Parkin & Schembri — actual field-paper scan, pp58–61 (2026-09-26)
- Rasmussen et al. 2014 — Australian sea-snake review (2026-09-26)
- ANZCOR — Australian snake bite first aid (2026-09-26)
Still not sure?
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A profile is a guide, not a reason to approach or handle a snake.