Top 6 Interesting & Unusual Deep Sea Fish

Less than 5% of the Earth's oceans have been explored. In fact, human beings know more about space than what is contained in the deep seas. Fish that have evolved to live in the dark and high-pressure environments of the deepest oceans also have some unusual and quirky physical attributes. This list explores some of these quirks and describes how these fish live and hunt.

The Humpback anglerfish belongs to the family of fish called Melanocetidae, which is also known as the black seadevils, another name for it is the Humpback Blackdevil.

This fish is black in colour and can live at such depths of up to 4500 meters but generally stays above 1500 meters. It can be found all over the world, from tropical seas to the Ross Sea in Antarctica. It was first discovered by a man named James Johnson who was an English naturalist in the eighteen hundreds.

The females of the species can reach 18cm in length, this is substantially larger than the males which do not even reach 3cm in length.

To attract prey the anglerfish has a fishing lure attached to the front of its head, also known as an illicium. It can fill its stomach to a very large capacity. In one case a humpback anglerfish has been found with a stomach containing 3 fish each with a length of over 3cm.

The pelican eel has been found in both temperate and tropical oceans. It can travel as deep as 3000m but can also be found as close to the surface as 500m. It is rarely ever seen by humans, though it is occasionally caught in fishing nets. It is also referred to as the gulper eel, pelican gulper, and umbrella-mouth gulper.

Its mouth is far larger than its body and it can be unhinged to allow the eel to swallow other fish which are even larger than the eel itself. They have very small eyes and they hunt by detecting fiant light rather than detecting images. They attract their pray (usually small crustaceans) by using their tails to make bright flashes of light as they move. They are black in colour and sometimes have a thin white stripe. The pelican eel's very long whip-like tail has been known to get knotted in fishing nets and dragged up to the surface.

Fossils of the Gonostomatidae date it as old as between 23 to 5 million years, the first living bristlemouths were discovered in the 1930s. It can be found in the Atlantic, Indian, Pacific and Arctic waters. Their lengths can vary from 2cm to 30cm and they are usually black in colour to protect them from other predators. They also emit colours of green and red.

There are many different types of Gonostomatidae, each with different qualities. Some of which live at depths below 1000m.

Flabby Whalefish can vary in size from quite small to up to 40cm, and they have been recorded at depths below 3500m. They have been found in oceans all over the southern hemisphere.

The eyes of the flabby whalefish are so small that they are not useful to the fish for hunting. Instead, it senses its surroundings using vibrations that it feels with its skin. The whalefish is orange and red in colour, however, these colours of light do not penetrate very deep down through water which means that the fish appears black. This helps it to camouflage against predators.

Males and females hunt prey differently. The females have huge stomachs which allows them to swallow prey much larger than the whalefish itself. The males, however, do not eat anything. The jaws of the male fish fuse together when it goes through puberty into adulthood. The food that the male fish eats before puberty stays in the stomach of the male and it then digests the shells in its stomach throughout adulthood to sustain it.

The viperfish lives at depths of below 2500m, as a result, it has been difficult to discover more about this fish. What is generally known about this fish is that it has been found in all tropical and subtropical oceans, and examples have been found between 20cm and 35cm in length.

The Sloane's viperfish is renowned for the size of its teeth, which are so large that they overlap the jaws. It hunts by swimming at its prey and impaling it upon its teeth. This fish is in the Guinness Book of World Records for having the largest teeth relative to head size.

The black swallower can be found in tropical and subtropical waters, it is also present in the north Atlantic. It is a small fish, growing no bigger than 25cm but it has the ability to swallow fish much much larger than itself. It hunts for prey at depths between 700m and 2745m. It is brown to black in colour and without scales which helps it to stay safe from predators.

When hunting, the black swallower takes its prey whole. It can eat prey far bigger than itself: up to twice its length and ten times its mass. It eats prey so large that it sometimes cannot digest it all before it dies, and the gases given off by the dead fish in its stomach helps it float to the surface of the ocean. This is how most black swallowers have been found in the wild.

If there are any fish that you think deserve to be on this list please do say so in the comments and I may edit this list to include them. Let me know which one is your favourite and what you found most interesting.