Enhydrina zweifeli snakes are found from New Guinea to Australia (Northern Territory and Queensland). In the past they were thought to be Enhydrina schistosa, but after DNA testing are now provisionally identified as Enhydrina zweifeli. DNA test have shown they are not related to Enhydrina schistosa. Enhydrina zweifeli are commonly known as the Sepik or Zweifel’s beaked seasnake. Enhydrina zweifeli is a highly venomous species of sea snake. Studied Enhydrina zweifeli have been near the mouth of Sepik River of New Guinea.