Pelican eel

The pelican eel lives in the deep sea.

It has a very big mouth. The mouth can open wide to swallow big fish. This mouth can even stretch like an umbrella.

The eel is dark to hide in the shadows. It has a long tail that glows. The tail can flash pink and red. This light helps the eel find food. It is a very strange fish.

The pelican eel lives in the deep, dark ocean.

It has a very large mouth. This mouth is much bigger than its body. The jaw can be about one quarter of the eel's total length. When it hunts, the mouth can change shape. It unfolds and then stretches wide like an umbrella. This helps the eel catch prey in a lunge feeding way. This means the eel swims fast toward its food.

The eel is often black or olive. It uses ultra-black camouflage to hide. This special skin reflects very little light. It helps the eel stay hidden in the shadows. The eel also has a long, whip-like tail. The tip of the tail has photophores. These are tiny parts that make light. The tail glows pink and flashes red. This light may act as a lure to attract food. When the eel is first born, it is a larva. These tiny eels are very thin and clear. We call this stage the leptocephalus stage.

The pelican eel is a strange fish from the deep sea.

It belongs to a group called the Eurypharyngidae family. Many people also call it a gulper eel. Some even call it an umbrella-mouth gulper. Its name comes from its huge mouth. This mouth looks a lot like the beak of a pelican bird. This eel is very important to study. It shows us how animals survive in the dark, deep parts of the ocean.

This eel has a very special way of eating.

Its mouth is much larger than its own body. The jaw can be one quarter of the eel's total length. When it hunts, the mouth goes through a two-step change. First, the jaw unfolds and spreads out wide. Next, the skin stretches to make the mouth look huge. This is called lunge feeding. The eel swims toward prey and scoops it up. It then pushes the extra water out through its gills.

Scientists have studied these eels for a long time. Many different names were used for them in the past. In 2003, researchers from the University of Tokyo studied their DNA. They looked at the genetic code of the pelican eel. They found it was closely related to the Saccopharynx lavenbergi. Most of what we know comes from fishing nets. In 2018, researchers near the Azores saw a gulper eel in person. They watched how aggressively it hunted in the water.

Pelican eels have many amazing physical traits. They use ultra-black camouflage to hide in the dark. This skin reflects less than 0.5% of light. Their tails are long and look like whips. The end of the tail has pink light-emitting spots called photophores. These lights flash red to lure in prey. Most eels have W-shaped muscle segments. However, the pelican eel has V-shaped muscle segments. They also have very small eyes to find faint light.

These eels live in many different parts of the world. They can be found in tropical and temperate oceans. One specimen was found in the Davis Strait near Canada. They also live near Greenland and the Hawaiian islands. When they are first born, they are called leptocephali. These tiny larvae are very thin and clear. They eat something called marine snow to grow. As they get older, they change into the large eels we see today.

The pelican eel, known scientifically as Eurypharynx pelecanoides, is a unique deep-sea fish. It is the only member of its genus and family, Eurypharyngidae. While it was once placed in its own order, scientists now classify it as a true eel within the order Anguilliformes. This species is often called a gulper eel or an umbrella-mouth gulper. Its scientific name, pelecanoides, refers to the pelican because of its massive mouth. This eel is a fascinating example of how life adapts to the extreme conditions of the deep ocean.

The most striking feature of the pelican eel is its enormous mouth. The jaw is so large that it can account for about one-quarter of the eel's total length. To feed, the eel uses a dual-mode biological morphing mechanism. First, the head and jaw undergo geometric unfolding, spreading horizontally. Second, the highly stretchable skin of the head allows the mouth to inflate. This process enables lunge feeding, where the eel scoops up large amounts of prey. Once the meal is swallowed, the eel expels the ingested water through its gills.

Pelican eels possess several specialized physical traits that differ from typical fish. Most fish have W-shaped muscle segments, but the pelican eel has V-shaped segments. Instead of a swim bladder, it has an aglomerular kidney. This kidney helps maintain gelatinous substance in lymphatic spaces around the vertebrae. These spaces are thought to function like a swim bladder to assist with buoyancy. Additionally, the ampullae of the lateral line system project from the body. This projection may increase the eel's sensitivity to movements in the water.

Survival in the dark bathypelagic zone requires incredible camouflage. The pelican eel uses ultra-black camouflage to hide from predators and prey. This special pigmentation is so dark that it reflects less than 0.5% of light. Its eyes are very small, likely evolved to detect faint traces of light rather than clear images. For movement and communication, the eel uses a long, whip-like tail. The tip of this tail features photophores, which are light-emitting organs. These organs glow pink and produce red flashes to act as a lure for prey.

The life cycle of the pelican eel begins in the leptocephalus stage. These larvae are extremely thin, transparent, and lack red blood cells. During this stage, they feed on marine snow, which includes organisms like thraustochytrids and hydrozoan tissue. As they mature into adults, their teeth change from fewer, larger, inward-pointing teeth to more numerous, smaller teeth. Sexual dimorphism, or physical differences between sexes, becomes apparent during maturity. Males develop a large, bulb-shaped nasal rosette to help them locate mates via pheromones. In males, the testes can occupy much of the stomach cavity.

History shows that much of our knowledge comes from accidental encounters. Because they live at extreme depths, many specimens are caught in deep-sea fishing nets. Since 1970, hundreds of specimens have been recovered, mostly in the Atlantic Ocean. Direct observations are rare, but significant progress occurred in 2018. Researchers near the Azores made the first direct observation of a gulper eel. They witnessed its aggressive hunting behavior in the water column. Another team from the E/V Nautilus observed a juvenile inflating its mouth in the Papahānaumokuākea Marine National Monument.

Pelican eels have a wide global distribution across temperate and tropical oceans. They have been found near the Hawaiian islands, the coast of Portugal, and Greenland. In the North Atlantic, they inhabit depths ranging from 500 to 2,000 meters. One specimen was even recorded in the Davis Strait at a depth of 1,000 meters. Their diet primarily consists of small crustaceans, though they also eat squid and other invertebrates. While their jaws are massive, they have tiny teeth, suggesting they use their mouths to capture a wide variety of prey when food is scarce. This flexibility is vital in a low-biomass environment.