Deepstaria enigmatica is a very rarely seen giant jellyfish of the family Ulmaridae first described in 1967 by F. S. Russell.
The Deepstaria enigmatica has a wide, thin bell (up to 60 cm or 2 ft), transparent in appearance, which undulates as the jellyfish moves. They are usually found in Antarctic and near-Antarctic seas, but have been spotted in waters near the United Kingdom and Gulf of Mexico, at depths of 600–1,750 metres (1,970–5,740 ft). Unlike many other jellyfish, they lack tentacles. They also are solitary creatures, contrary to the group living style of many jellyfish.
The large bell of the jellyfish has been proposed as used for either locomotion or feeding when closed. The Deepstaria also features a geometric mesh pattern throughout its bell; this mesh, being the gastrovascular system, delivers nutrients to the entire jelly as it stretches and contracts to move and capture prey.
The Deepstaria jellyfish, unlike many jellyfish, lacks tentacles of any kind, which other species of jellyfish commonly use to entrap and consume prey. Instead, Deepstaria trap prey inside their bell, where they are consumed. This method also provides for isopods, who may live inside the jellyfish's bell in a symbiotic relationship.
