Hydrelaps

Hydrelaps is a genus in the family Elapidae, the same family that holds cobras, mambas, taipans, and the marine sea snakes. It contains a single recognized species, Hydrelaps darwiniensis, the Black-ringed Sea Snake, sometimes called the Port Darwin sea snake. It belongs to the fully marine elapid group, the snakes that gave up the land entirely and bear live young in the water rather than laying eggs. Within that group it sits among the smaller, more secretive species rather than the large open-water hunters.

The species is found across the shallow coastal waters of northern Australia and southern New Guinea, where it favors muddy estuaries, tidal mudflats, and mangrove margins rather than deep reef or open sea. It is a small snake, generally well under a meter in length, with a slender body and the flattened, paddle-like tail shared by sea snakes that helps it swim. The common name points to its pattern of dark bands or rings along a paler body. Like other true sea snakes it has valved nostrils and adaptations for staying submerged, and it tends to keep to soft-bottomed, shallow habitat where it hunts in mud and burrows.

Hydrelaps darwiniensis is venomous, as all elapids are, and it should be treated with the same caution as any sea snake. Sea snakes are generally not aggressive and bites on people are uncommon, but this is a wild venomous animal and not one to handle. If anyone is bitten by a sea snake, treat it as a medical emergency, keep the person still, and seek emergency care immediately. In the United States contact Poison Control at 1-800-222-1222 or call local emergency services; elsewhere call your local emergency number. Its diet is thought to consist of small fish and other prey taken in the shallow muddy habitat it occupies, and like other marine elapids it gives birth to live young in the water rather than coming ashore to nest.