The Pelican eel (Eurypharynx pelecanoides), aptly named after its huge pelican-like mouth, is able to swallow prey much larger than itself. This deep sea eel is a resident in the mesopelagic zone, but has also been known to go deeper down to the bathypelagic down, at around 3000 meters.

The Pelican Eel is also known as the Gulper Eel. When hunting prey it swims with its mouth open, able to gulp multiple small pray at once. The excess water ingested is then flushed over its gills.

The Pelican Eel is also known as the Gulper Eel. When hunting prey it swims with its mouth open, able to gulp multiple small pray at once. The excess water ingested is then flushed over its gills.

Although it is a deep sea fish it doesn’t have large, sensitive eyes. Rather, its small eyes (a few millimeters in diameter) are likely adapted to detect small traces of light instead of forming images. The lateral line organ of the pelican eel is also projecting from its body, instead of being contained within a groove. This might increase its sensitivity to detect vibrations in the water!

The pelican eel also has a long tail, ending with bioluminescense organs known as photophores. It can use this organ to produce light, glowing pink and occasionally flashing bright red.

The pelican eel also has a long tail, ending with bioluminescense organs known as photophores. It can use this organ to produce light, glowing pink and occasionally flashing bright red.

The pelican eels extended whip-like tail is used for swimming, but also to produce light. At the end of its tail, the pelican eel can produce both pink and red light through bioluminescense. This light may be used for communication, but could also act as a lure to attract prey.

A photography of a Pelican eel, by Alexei Orlov

With its ability to extend both its mouth and stomach - much like a balloon - the Pelican eel is able to gulp a huge amount of water, capturing unsuspecting prey in the deep sea. Its extremely unusual body and features makes it a successfull predator in the dark, deep depths of the mesopelagic zone and below.

Just can’t get enough of the deep sea? Sate your thirst with the video below!