|Swallowers and gulpers|
Pelican eel, Eurypharynx pelecanoides. From plate 49 of Oceanic Ichthyology by G. Brown Goode and Tarleton H. Bean, published 1896.
Saccopharyngiformes is an order of unusual ray-finned fish superficially similar to eels, but with many internal differences. Most of the fish in this order are deep-sea types known from only a handful of specimens.
Saccopharyngiforms lack several bones, such as the symplectic bone, the bones of the opercle, and ribs. They also have no scales, pelvic fins, or swim bladder. The jaws are quite large, and several types are notable for being able to consume fish larger than themselves. Their myomeres (muscle segments) are V-shaped instead of W-shaped like in all other fish, and their lateral line has no pores, instead it is modified to groups of elevated tubules.
There are four families in the order:
- Cyematidae (bobtail snipe eels)
Eurypharyngidae (pelican eel)
Saccopharyngidae (swallowers, gulpers or gulper eels)
The gulper eel eats fish, copepods, shrimp, and plankton. It uses its mouth like a net by opening its large mouth and swimming at its prey.