Pelican Eel: Habitat and Characteristics

Written and verified by the biologist Francisco Morata Carramolino

Last update: 21 December, 2022

The ocean depths, where light is non-existent, hide innumerable secrets. In this world that’s practically unexplored and almost alien to human influence, fauna has developed incredible forms. They’re so alien to our perception that they’re difficult to understand with the naked eye. The pelican eel is a clear example of this.

Among all these monstrous creatures, the pelican eel (Eurypharynx pelecanoides) is an especially unlikely one. It appears to be abundant and well distributed, although it’s rarely found in its natural environment by humans. Because of this, its biological makeup is still very unknown.

Even so, this species has some contact with humans, since hundreds of specimens have fallen into fishermen’s nets since the 1970s, especially in the Atlantic Ocean. If you want to learn more about this alien-looking fish, its habitat, characteristics, and conservation status, we invite you to continue reading this article.

Pelican eel habitat

The pelican eel has a very extensive distribution. It occurs in temperate and tropical oceans around the world and occupies a wide range of depths. It can be found from 500 to 7625 meters deep (1640 to 25000 feet), although it’s more frequently between 1200 and 1400 meters.

This corresponds to the bathyal or bathypelagic zone. Sunlight doesn’t reach this area, and so it’s almost complete darkness. This prevents the typical surface organisms that result from photosynthesis, and so there are hardly any primary producers in this section of the water column. In addition, the pressure is very high and the temperatures are low.

All of this imposes enormous evolutionary demands on deep-sea life forms, which have been strongly conditioned and transformed until they reach their current representative appearance. The pelican fish is a clear example of adaptations to an inhospitable environment, as we’ll see below.

Physical characteristics

This species belongs to the order Anguilliformes. Therefore, it can be said that it is an eel in essence, which we can see from some of its physical qualities. However, adaptations to bathypelagic life have alienated it from the more typical eels.

These fish are almost never observed alive, as exploring their ecosystems is very difficult for humans. Although they’re sometimes dragged to the surface by fishing nets, their bodies are fragile and deteriorate from the change in pressure during ascent.

Pelican eels appear to measure between 50 centimeters and 1 meter (1.6 to 3.2 feet). Their bodies are simple, laterally flattened, and completely black. They have a long, fine, whip-shaped tail that narrows as it moves away from the body. Their fins are absent or severely reduced.

The most striking aspect is this animal’s huge head, which accounts for most of the body length. This cephalic region bears a disproportionate mouth, with gigantic protruding jaws that extend backward. These jaws carry a very extensible membrane.

The jaws may be retracted on the sides of the body, giving a more conventional eel look, but may also extend perpendicular to each side of the body plane.

At certain times, pelican eels greatly swell their membrane, which occupies almost the entire body. This makes them look like a balloon or a very inflated tadpole, with the thin flattened tail sticking out from behind.

Finally, it should be noted that this eel’s eyes are tiny and are located on the tip of the head, in front of the jaw. In general, the appearance of the animal seems otherworldly and could be defined as grotesque.

Behavior and ecology of the pelican fish

Again, very little is known about this animal’s way of life. Its diet has been deduced through studies of its stomach contents. It isn’t very selective and includes crustaceans, cephalopods, algae, fish, and other marine invertebrates. Its huge mouth and flexible body allow it to consume large prey.

Until a few years ago, people had never seen how this animal feeds. However, researchers managed to record E. pelecanoides hunting in 2018, a milestone for the world’s marine biologists specializing in strange creatures.

These videos demonstrate that the pelican fish actively hunts and chases its prey. The large inflatable mouth increases the chances of catching its victims. Although observing behavior is fascinating firsthand, this contradicts previous hypotheses, which suggested more passive strategies.

Regarding reproduction, these fish are oviparous. In addition, it’s believed that they are semelparous. This means that they reproduce only once during their lives, after which they die and make way for the next generation. The young are very small and semitransparent; they carry very small organs and lack red blood cells. This pre-juvenile stage is known as leptocephalus.

As they grow, the males undergo very remarkable morphological changes. In contrast, females don’t vary so much throughout their development.

State of conservation

Pelican eels were previously believed to be rare, but current knowledge seems to indicate otherwise. This species is estimated to be numerous and forms a dominant part of deep-sea fish communities.

In addition, at the moment no significant threats have been detected for this animal. This could be due to the remote ecosystems that it inhabits, which are more protected from human actions than many others. Still, the pelican eel is a frequent victim of deep-sea fishing in parts of its range.

Fortunately, the extensive distribution and large numbers of individuals keep the populations safe for the time being. Accordingly, the species is classified as of least concern by the International Union for Conservation of Nature (IUCN).

This peculiar fish is just one example of the rarities that we can find in the depths of our oceans. Although these creatures can be shocking and even repulsive, they’re worthy of our study, admiration and, above all, conservation.