See text Saccopharynx is a genus of deep-sea eels with large mouths, distensible stomachs and long, scaleless bodies.

It is the only genus in the family Saccopharyngidae, and is part of the derived lineage of the "saccopharyngiforms," which includes other mid-water eel species.

They have been found at depths of 1,800 metres (5,900 ft), and are known to inhabit the eastern and western Atlantic Ocean and the Gulf Stream.

The exact purpose of this organ is unknown, although it is most likely used as a lure, similar to the esca of anglerfish.

It has a stretchy stomach that can hold large meals, which is very useful in the deep sea, where food is hard to come by.