Pelican eel

About the Pelican eel

It’s a bird, it’s an eel, it’s… neither of those things. Equipped with a large, scoop-like jaw, this deep-sea fish was first named after a pelican. But as researchers learned more about its behavior, other names emerged. “Gulper eel” sums up the fish’s ability to expand its throat and stomach to accommodate food—and the copious amounts of water that it slowly expels through its gills.

“Umbrella-mouth gulper” might be the most appropriate of its many names. When it encounters prey, this fish blows up its mouth to impressive dimensions, creating a massive net that can scoop up a squid or a swarm of shrimp. Its balloon-like capacity is a helpful adaptation for an opportunistic eater—the tiny teeth that line its jaws certainly wouldn’t be up to the job alone.

Despite the fearsome size of its mouth, however, the pelican eel isn’t a particularly athletic hunter. It has extremely small eyes compared to other denizens of the deep, so can’t rely on sight to locate prey. Instead, the pelican eel uses a pink (or occasionally red) light on its rear fins to lure its next meal. It’s also not much of a swimmer—with a whip-like tail and a lack of pelvic fins, swim bladders and scales, it’s not built for going long distances. This could be why pelican eels remain at depths of 500 to 3,000 meters (1,600 to 9,800 feet) instead of joining their twilight zone buddies on a nightly migration to the surface for dinner.

Not that it’s goofing off. While it drifts around in the deep, the pelican eel puts much of its spare energy into finding a mate. Sexually mature males grow larger olfactory organs (which regulate the sense of smell) in order to sniff out females, while simultaneously losing their teeth. Researchers think this happens because the fish is putting all its resources into reproduction (who hasn’t lost their appetite when in love?) and will die soon after mating.