The Fascinating World of 8 Deep-Sea Creatures

The deepest parts of the world’s oceans hold some of the strangest creatures known to science. We are going to take a look at a few different species that live in the deep, dark abyss; including how deep they are found, how they hunt or defend themselves, and some other interesting facts that separate deep-sea creatures from shallower marine species. This group of highly adapted aquatic oddities have overcome incredible challenges created by their environment to survive and thrive in extreme depths.

8 Incredible Deep-Sea Creatures

1. Gulper Eel

This eel gets its name from its unique adaptation for feeding, which allows it to take advantage of possible meals it comes across in the darkness. Its jaw extends significantly behind the skull, and when combined with an elastic skin membrane, the mouth can inflate into a large balloon-like sac.

This adaptation lets the eel fill the cavity with as many of its preferred crustacean prey as possible when it stumbles upon an aggregation of them. This eel can reach lengths of 0.9-1.8 meters (3-6 feet) and is found at depths from 457-3048 meters (1500-10,000 feet) in oceans around the globe except the poles. Truly a unique deep-sea creature!

Do you love learning about marine creatures? Here are 11 Amazing Facts About Turtles (and How to Tell Them Apart).

2. Giant Isopods

These deep-sea creatures look similar to a pill bug but grow up to 30 centimeters (1 foot) long and can be found in abundant numbers on the deep seabed. They are expert scavengers and have very keen chemosensory antennae that allow them to pick up the scent of possible feeding opportunities that fall down from the waters above.

They are usually the first animals to arrive at the scene of a dead animal landing onto the abyssal plains, and they leave no scrap behind!

Stripping skeletons to bare bone in a short time, giant isopods make the most of a feast. They are found around the world (except for the poles) and in depths ranging from 152-2438 meters (500-8000 feet).

3. Giant Tube Worms

These unusual animals are only found on the black smokers in the Pacific Ocean, creating large calcareous tubes to protect their bodies. Black smokers are hydrothermal vents that spew out superheated water into the depths, packed full of minerals and chemicals including sulfur.

Giant tubeworms can grow up to 2.7 meters (9 feet) long and utilize sulfur-fixing bacteria in a symbiotic relationship to create energy for themselves. When black smokers and their wildlife (including the giant tube worms) were discovered in the 1970s, they caused great excitement for scientists. These environments have no sunlight input into the food chain and yet support a magnitude of life!

Giant tube worms are typically found at specific sites over 1524 meters (5000 feet) deep in the Pacific Ocean.

Many deep-sea creatures use bioluminescence as a way to see in the deep, dark waters. Read more about it here: Bioluminescence: What is it and Where to See it.

4. Angler fish

Angler fish are well known deep-sea creatures with many different species found across the globe, but they all exhibit similar features. They have a large rounded body, a huge cavernous mouth, and a multitude of small needle sharp teeth. These teeth fold into the mouth but lock on exit to stop prey from escaping.

And of course, there is the feature that gives these fish their name; their lure like appendage dangling off the skull over the mouth.

Many angler fish utilize bioluminescence in their lures to make them even more enticing to prey items in the depths. Angler fish can range in size from 5.1-7.6 centimeters (2-3 inches) to over 30 centimeters (1 foot) in diameter and live at a depth range of 91-1524+ meters (300-5000+ feet).

5. Chimeras

These strange creatures are often called rat fish and, although they look like a bony fish, they actually have a cartilage skeleton, making them living ancestors of modern day sharks and rays!

Chimeras predate upon small crustaceans and fish they come into contact with in the darkness. They have large eyes and pointed snouts and can reach lengths of up to 1.5 meters (5 feet), although most are much smaller.

Scientists often study chimeras to see if they can gain clues as to the development of the anatomy and physiology of species we see around the world as recognizable shark species. Chimeras have been found as deep as 2591 meters (8500 feet) but will rarely be found in less than 183 meters (600 feet) of water.

6. Dumbo Octopus

This adorable little octopus is perhaps the deepest of our eight deep-sea creatures: they only live deeper than 3962 meters (13000 feet). Many have been observed by ROVs during exploratory dives, and as they have quite a cute appearance, they have gained a lot of fans around the world.

They get their name from the two small fleshy appendages on the sides of their heads that look like an elephant’s ears. They are small predators that eat invertebrates on the seafloor, and they rarely grow over 30 centimeters (1 foot) in diameter, but larger specimens have been observed.

Do you know the difference between a squid and an octopus? Check this out: Squid Vs Octopus: What is the difference?

7. Oarfish

The longest bony fish in the world, the oarfish can measure over 9 meters (30 feet) from head to tail and it is typically only seen when it occasionally washes up on shores around the world. It has been observed alive in the water on just a handful of occasions by humans.

This strange-looking fish is likely to have been the animal described by fishermen and sailors as sea serpents.

Oarfish have an iridescent sheen across their silvery bodies. When they are feeding or resting in the depths, they hang motionless and vertical in the water column filter feeding on zooplankton. This body position is thought to make the oarfish profile less visible to predators like sharks.

These fish are thought to typically inhabit depths of over 305 meters (1000 feet) and can be found around the world.

8. Giant Squid

The true denizens of the deep, the giant squid is a revered animal that has folklore from around the world and it is perfectly adapted to life in the cold water where the pressures are extreme.

Giant squid have reached lengths of over 9 meters (30 feet) but many unconfirmed reports in history have said they can be much larger than that!

They have huge eyes that can be the size of a grapefruit, so they can use what little light exists in the deep. The suckers on their feeding arms have sharp hooks that can spin 360 degrees to ensure any prey cannot escape.

They are fast predators and it is thought they will attack most creatures if they deem them suitable as a meal, including sharks, fishes, and small cetaceans, or mammals.

They have been observed alive at over 914 meters (3000 feet) by scientists off the coast of Japan, but it is thought they are capable of living much deeper in the ocean as long as prey are available. Giant squid only have one predator and that is the mighty sperm whale.

I think we can all agree that these deep-sea creatures are truly fascinating. Which was your favorite?

Discover more incredible wildlife you can encounter in the ocean on SSI’s MyDiveGuide.