Hydrophyidae

A family of snakes, the true sea snakes, characterized by a vertically compressed tail, giving it a paddle- or oarlike appearance; their fangs, like those of cobras, are small, grooved, and permanently erect. They are common in shallow waters along coastal margins in many regions of the Pacific basin and are important medically in western Malaysia and coastal Vietnam. There are numerous species, all venomous, but few bite humans.