Today we will be looking at the Pelican Eel (Aka Gulper eel)! Don’t let that name fool you though, it is neither a bird nor an eel.
This deep-sea dwelling fish was first named after a pelican, but once researchers began to learn more about its behavior, the name Gulper eel (among others) emerged which sums up the fish’s ability to expand its throat and stomach to accommodate food but also as a defense mechanism. When it comes to catching prey, pelican eels blow up its mouth to impressive dimensions which forms a net that can scoop up a squid or a swarm of shrimp, all in one quick gulp. That ability to blow itself up like a balloon was a handy adaptation for this opportunist.
Pelican eels aren’t entirely athletic hunters. With small beady eyes, these fish use a pink light on their rear fin to lure in prey. Not only do these fellows have tiny eyes, but they are also not the strongest swimmers— equipped with a whip-like tail and a lack of pelvic fins, swim bladders, and scales, it can’t do long-distance swimming. This may be the reason why pelican eels remain at depths of 500 to 3,000 meters (1,600-9,800ft) instead of joining their twilight zone buddies on a nightly migration to the surface for midnight snacks.
Pelican eels put much of their spare energy into finding a mate. Mature males grow larger olfactory organs (which regulate smell) in order to sniff out females, while simultaneously losing their teeth. Researchers believe it is due to the fish putting all of its resources into production to die soon after mating.
And that is the Pelican eel! Below, I've included a fun video of a group of researchers reacting to the fish's expanded throat. As usual, I'll be including sources as well as a gallery of Pelican eel closeups.