Pelican eel
The Gulper eel, or pelican eel, is a deep-sea fish belonging to the family Eurypharingidae, characterized by its distinctively large mouth and throat, which allow it to consume small creatures like plankton and crustaceans. This eel typically measures around 2.5 feet (0.75 meters) in length and possesses a slender body that tapers into a ribbon-like tail. Its mouth can open wide, resembling that of a pelican, giving it its nickname. The eel’s body is primarily black with lateral line sensors that detect changes in water pressure, helping it locate prey in the dark depths of the ocean.
Found in the Atlantic, Indian, and Pacific Oceans, the Gulper eel inhabits deep waters, although its precise depth range remains uncertain. It is believed to have a long lifespan, possibly exceeding 80 years, but little is known about its reproductive habits. Young Gulper eels, known as leptocephali, hatch from eggs and undergo metamorphosis at around 1.5 inches (four centimeters) before moving to deeper waters as they mature. Despite being difficult to study due to their habitat, the Gulper eel is not considered threatened by fishing activities. Overall, much about this enigmatic creature remains a mystery.
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Gulper eel, or Eurypharingid eel
The pelican eel is a deep-sea eel with a large, gaping mouth and throat for swallowing tiny creatures, such as plankton, crustaceans, other small invertebrates, or creatures without backbones. The mouth and throat are the source of the eel's nickname, the pelican eel.
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Saccopharyngiformes
Family: Eurypharingidae
Genus: Eurypharynx
Species: Pelecanoides
This eel is simply called a pelican eel, or is called by its family name as a Eurypharingid eel. Very little is known about this species.
The pelican eel has a slender body, as is typical for eels. The eel's distinguishing features are its huge mouth and throat, which make the eel look quite strange when the mouth is open. The long jaws extend several inches (centimeters) behind the small eyes, which perch on the tip of the snout and flattened head. The gaping opening of the mouth looks as though it leads directly and immediately into one huge stomach, which takes the place of the rest of the body. The eel's body itself is short and thick, but then begins tapering into a long tail, which at its end is as thin as a ribbon.
An adult pelican eel grows to be about 2 1/2 feet (3/4 meter) long from snout to tip of tail. The jaws may be as much as 25 percent, or nine inches (23 centimeters), of the eel's overall length. Because it can open its mouth so widely, such that it resembles the mouth of a pelican, the eel has the nickname pelican eel.
The eel's body is black. Along each of its sides runs a line of tiny openings, or pores. These are called lateral line sensors. They detect changes in water pressure from motion. These pressure changes alert the eel that other creatures may be nearby, some of which may be prey. Another feature of the body is the two white stripes which run along either side of the dorsal fin. These stripes glow slightly, but it is not known what purpose they serve. A small organ near the tip of the tail may also glow, but this has not been determined.
Two small pectoral fins are attached low on the eel's sides midway between the mouth and the where the tail begins tapering. The eel's long, low dorsal, or back, fin begins where the body and stomach end and runs the entire length of the body and along part of the tail. The rest of the tail has tiny, single fins on either side. The anal, or rear, fin runs along the body's underside from behind the stomach to where the tail becomes ribbon-like.
The pelican eel lives in the deep waters of the Atlantic, Indian, and Pacific Oceans. Exact depths are not certain. Its relative, the whiptail gulper eel, lives at depths between 1,065 and 2,665 fathoms, or 6,400 and 16,000 feet (2,000 and 5,000 meters). It is likely that the habitats of the two are the same or similar.
As it cruises along through the water with its mouth open, the eel swallows, or gulps, small creatures in the water. It chiefly consumes plankton and small invertebrates, or creatures without backbones, such as shrimp and other crustaceans. Unlike the whiptail gulper, the stomach of this species does not stretch to hold large prey or great quantities of food. It also has tiny teeth in its huge mouth. Large fish such as the lancetfish and other deep sea creatures prey upon the pelican eel.
Because this eel lives in such deep waters, it is rarely seen and is in no danger from fishermen. These depths, however, also make it difficult to study. As a result, very little is known about the eel. However, the pelican eel is believed to have a life span of over 80 years.
Information is also lacking about this eel's mating habits. The young hatch from eggs as larvae. In this larval stage they are called leptocephali. How long they remain leptocephali is not known, but when they are around 1 1/2 inches (four centimeters) long, their bodies metamorphose. This means they change from looking like clear willow leaves to looking like miniature adults, large mouth included. Until they are older, the young live at depths of 330 to 660 feet (100 to 200 meters) deep. They then swim to lower depths as adults.
Some people believe that this is the only species in this family, while others claim to have identified another species, Eurypharynx richardi. This species may be a little over one foot (30 centimeters) long.
Although the pelican eel is difficult to study, it is not believed to be a threatened species.
Bibliography
Caiger, Paul. “Creature Feature: Pelican Eel.” The Ocean Twilight Zone, 2024, twilightzone.whoi.edu/explore-the-otz/creature-features/pelican-eel. Accessed 8 Apr. 2024.
“Pelican Eel, Eurypharynx Pelecanoides Vaillant, 1882.” Australian Museum, 16 Apr. 2021, australian.museum/learn/animals/fishes/pelican-eel-eurypharynx-pelecanoides. Accessed 8 Apr. 2024.