The surf eel (Ichthyapus ophioneus), also known as the Finless snake eel in the United States, is an eel in the family Ophichthidae (worm/snake eels). It was described by Barton Warren Evermann and Millard Caleb Marsh in 1900, originally under the genus Sphagebranchus. It is a marine, tropical eel which is known from the western and eastern Atlantic Ocean, including Bermuda, the Bahamas, Florida, USA; Puerto Rico, the Virgin Islands, northern South America, and St. Helena Island. It dwells at a maximum depth of , most often between , and forms burrows in sand bottoms in surf areas, from which its common name is derived. Males can reach a maximum total length of .