The ocean depths, where light is non-existent, hide countless secrets. In this practically unexplored world, and almost alien to human influence, the fauna has developed incredible forms, so alien to our perception that they are difficult to understand with the naked eye. The Pelican eel is a clear example of this.
Among this collection of monstrous creatures, the Pelican eel (Eurypharynx pelecanoides) is particularly unlikely. It seems to be abundant and well distributed, although it is rarely encountered in the natural environment by humans. Therefore, its biology remains largely unknown.
Even so, this species has some contact with humans, as since the 1970s hundreds of this species have fallen into fishermen’s nets, 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.
Habitat of the Pelican eel
The Pelican eel (Eurypharynx pelecanoides) has a very wide distribution. It occurs in temperate and tropical oceans worldwide and occupies a wide range of depths. It can be found from 500 to 7625 meters depth, although it is most common between 1200 and 1400 meters.
This corresponds to the bathyal or bathypelagic zone. Sunlight does not reach this zone, so darkness is almost total. This prevents typical surface organisms from photosynthesizing, so there are hardly any primary producers in this section of the water column. In addition, the pressure is very high and temperatures are low.
All this imposes enormous evolutionary demands on deep-sea life forms, which have been strongly conditioned and transformed to reach their current representative appearance. The Pelican eel is a clear example of adaptations to an inhospitable environment, as we will see below.
This species belongs to the order Anguilliformes. Therefore, it can be said to be an eel-like species, which is suggested by some of its physical qualities. However, adaptations to bathypelagic life have moved it away from the more typical eels.
These fish are almost never observed alive, since exploring their ecosystems is very difficult for humans. Although they are sometimes hauled to the surface by fishing nets, their bodies are fragile and are damaged by the change in pressure during the ascent. As a result, the specimens fished are very altered.
Pelican eels appear to measure between 50 centimeters and 1 meter. Their body is simple, flattened laterally and completely black. They have a long, thin, whip-like tail, which narrows as it moves away from the body. Their fins are absent or very reduced.
The most striking aspect is the enormous head of this animal, which occupies most of the body length. This cephalic region carries a disproportionate mouth, with gigantic protruding jaws that extend backwards. These structures carry a highly extensible membrane.
The jaws may be retracted on the sides of the body, giving a more conventional eel-like appearance, but also extend perpendicularly on either side of the body plane.
At certain times, Pelican eel fish swell their membrane very much, which occupies almost the entire body. This gives them the appearance of a balloon or a highly inflated tadpole, with the thin flattened tail protruding from behind.
Finally, it should be noted that the eyes of this eel are tiny and are located at the tip of the head, in front of the jaw. Overall, the animal’s appearance seems otherworldly and could be defined as grotesque.
Pelican eel behavior and ecology
Again, very little is known about the lifestyle of this animal. Its diet has been deduced through studies of its stomach contents. Its diet is not very selective and includes crustaceans, cephalopods, algae, fish and various other marine invertebrates. Its huge mouth and flexible body allow it to consume large prey.
Until a few years ago, this species had never been seen feeding. 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 eel actively hunts and pursues its prey. The large inflatable mouth increases the likelihood of catching its victims. Although observing the behavior is fascinating at first hand, this contradicts previous hypotheses, which suggested more passive strategies.
In terms of reproduction, these fish are oviparous. In addition, they are believed to be 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 semi-transparent, carry very small organs and lack red blood cells. This pre-juvenile stage is known as the leptocephalus.
As they grow, males undergo very noticeable morphological changes. Females, on the other hand, do not vary in such an extreme way throughout their development.
State of preservation
Pelican eels were previously thought to be low in abundance, 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, no significant threats to this animal have been detected so far. This could be due to the very remote ecosystems it inhabits, which remain more protected from human actions than many others. Even so, the Pelican eel is a frequent victim of deep-sea fishing in parts of its range.
Fortunately, the wide distribution and large number of fish keep the populations safe for the time being. Accordingly, the species is classified as “Least Concern (LC)” by the International Union for Conservation of Nature (IUCN).
This particular fish is just one example of the oddities that the depths of our oceans harbor. Although these creatures can be shocking and even repulsive, they are worthy of our study, admiration and, above all, conservation.