Old illustration of a gulper eel opening and closing its mouth
Image credit: G. Brown Goode and Tarleton H. Bean

The gulper eel, whose scientific name is Eurypharynx pelecanoides, is a bizarre-looking fish that lives deep under the sea. Because these creatures live so far down in the ocean, it’s difficult for scientists to study them well. Almost all the information we currently have about these eels comes from studying specimens that became accidentally entangled in the nets of deep-sea fishermen.

Though it’s called an eel, its appearance is actually quite different from most other animals that are considered a part of the eel family. Unlike most marine eels, this bizarre animal has the following features: a long, wide jaw; a small abdomen; extremely small pectoral fins; no scales; extremely tiny teeth; and a photophore (glandular organ that looks like a glowing spot) on the tip of its tail. In addition to these strange features, perhaps the oddest part about this deep-sea creature’s appearance is its enormous, expanding mouth that earned it several nicknames, such pelican eel, pelican gulper, and umbrella-mouth gulper. They are not to be confused with the Saccopharynx ampullaceus, which is also sometimes called a gulper eel or pelican-fish.

These trademark mouths are loose and hinged in a way that allows them to swallow animals that are far larger than themselves, such as large squid, if necessary. Because they have such tiny teeth, however, scientists believe that they probably don’t often eat big animals; they would probably only do this if there was a food shortage.

Most often, when scientists are able to look at the contents of a gulper eel specimen’s stomach, they find small fish, crustaceans, seaweed, and squid. This fact, combined with the knowledge that deep-sea creatures use bioluminescent appendages as fishing lure, means that pelican eels probably prefer to lure food close to their giant mouths and then trap it inside their pouch-like lower jaws. They can also slowly swim into schools of fish or groups of shrimp and use their jaws as nets. This allows them to capture large amounts of food at once. They can then filter out the seawater that was taken in through their gill slits.

People have found these creatures in tropical and temperate regions of every ocean. Scientists estimate that they live at depths that range from 500-6,000 ft (150-1,800 m) below the surface of the sea. For perspective, most experienced human divers typically stop around 130 ft (40 m), and those who dive any deeper must be specially trained experts.

Old illustration of a gulper eel
Image source: Freshwater and Marine Image Bank. Image creator: David Starr Jordan.

How Much Do Gulper Eels Weigh?

Because so few specimens are able to be studied, there isn’t a clear answer. They typically grow to be 2.5 ft in length (0.7 m). Eels of comparable size can weigh around 20 lbs (9 kg). (Note here that pelican eels are technically not eels, but eel-like fish).

How Long Do Gulper Eels Live?

The short answer is that nobody knows for sure how long they live. Scientists have been able to figure out, though, that females typically die after they have spawned once.

How Many Babies Do Gulper Eels Have?

Again, due to the difficulty scientists have studying them, nobody knows for sure exactly how many eggs a female pelican eel can lay. However, various types of marine eels can lay anywhere from 10,000 to even 6 million eggs! (Note here that pelican eels are technically not eels, but eel-like fish).