What is "saccopharynx"

Saccopharynx is a genus of deep-sea eel-like fishes with large mouths, distensible stomachs and long, scaleless bodies. It is the only genus in the family Saccopharyngidae. The name is from Latin saccus meaning "sack" and Greek φάρυγξ, pharynx.

Like other saccopharyngiforms, fishes in this genus are known as gulpers or gulper eels.

They are generally black in color, and can grow to lengths of 2 m (6.5 feet). They have been found at depths of 1,800 m (6,000 ft). Their tails are tipped by a luminous, bulb-shaped organ. The exact purpose of this organ is unknown, although it is most likely used as a lure, similar to the esca of anglerfish.