Yellow sea snake (Hydrophis spiralis)

French: Hydrophide-spirale
GenusHydrophis (1)
SizeLength: up to 2.75 m (2)

The yellow sea snake is classified as Least Concern (LC) on the IUCN Red List (1).

The longest of the true sea snakes (Hydrophiids) (2) (3), the yellow sea snake (Hydrophis spiralis) has a striking yellow or yellowish-green body, boldly marked with 30 to 60 narrow, black rings (3) (4). The head is also yellow in adults, but in young individuals it is blackish with a distinctive yellow, horseshoe-shaped mark on the top (3) (4). The jaws bear small, fixed, tubular fangs, which are used to administer powerful venom (3).

Like most sea snakes, the tail of this species is flattened and paddle-like, helping to propel the snake through the water (3) (5). Other adaptations for living in water include nostrils placed on the top of the snout, so that breathing can take place without exposing the body to aerial predators (3). The nostrils are also valved, and close when this species is submerged (5).

The yellow sea snake’s expansive range extends from the Arabian Gulf, through the Indian Ocean, to Indonesia, the Philippines, Malaysia, Thailand, New South Wales (Australia) and Fiji (6) (7).

The yellow sea snake inhabits warm, shallow, near-shore waters, occurring over reefs, seagrass or sand, and sometimes also in estuaries (3) (7).

While little is known about the biology of this particular species (4), like other sea snakes it is well-adapted for life in the marine environment, completing its entire life cycle in the water, and never voluntarily coming ashore (3) (5). Fish, such as eels, are likely to be the main source of prey for this species, which it locates among crevices in rocks and coral reefs (3) (5).

Prey is caught by means of a swift bite, which administers the fast-acting venom, thereby killing the victim and also breaking down its tissues to aid digestion (3). Sea snakes typically give birth to a small number of fully-developed live young (3) (5).

The yellow sea snake appears to be common in many parts of its range (3) (7). Further study is necessary to determine whether it faces any significant threats.

While there are no known conservation measures in place for the yellow sea snake, the Environment Agency - Abu Dhabi is working towards a greater understanding of sea snake species found in the Arabian Gulf (8).

Learn more about conservation in the Arabian Gulf: 

 Learn more about reptile conservation: 

Authenticated (15/10/11) by Olivier S. G. Pauwels, Research Associate at the Royal Belgian Institute for Natural Sciences, Brussels, Belgium.

  1. IUCN Red List (April, 2011)
  2. Heatwole, H. (1999) Sea Snakes: Australian Natural History Series. UNSW Press, Sydney.
  3. Hellyer, P. and Aspinall, S. (2005) The Emirates: A Natural History. Trident Press Limited, United Arab Emirates.
  4. Levitón, A.E., Wogan, G.O.U., Koo, M.S., Zug, G.R., Lucas, R.S. and Vindum, J.V. (2003) The dangerously venomous snakes of Myanmar: Illustrated checklist with keys. Proceedings of the California Academy of Sciences, 54: 407-462.
  5. Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.
  6. The Reptile Database (October, 2011)
  7. Tomascik, T. (1997) The Ecology of the Indonesian Seas, Part 2. Tuttle Publishing, North Clarendon.
  8. Soorae, P.S., Das, H.S. and Al Mazrouei, H. (2006) Records of sea snakes (subfamily Hydrophiinae) from the coastal waters of the Abu Dhabi Emirate, United Arab Emirates. Zoology in the Middle East, 39: 109-110.