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Otherwordly Sea Creatures People Rarely See
Those ear-like appendages are used for swimming.

The Dumbo Octopus Swims With Its Ears

Do you remember the drug-infused movie Dumbo, which featured a baby elephant with ears that only a mother could love? Meet Dumbo’s underwater cousin, the dumbo octopus. This cephalopod has eight tentacles, just like any ordinary octopus.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Live Science

What sets the dumbo octopus apart is its ear-like appendages. Just like Dumbo the Elephant used his ears to fly, the dumbo octopus uses its ears to soar through the ocean’s depths. The dumbo octopus lives over the Mid-Atlantic Ridge, a giant underwater mountain chain that dwarfs the Himalayas.

Otherwordly Sea Creatures People Rarely See
This creature is a mollusk without a shell.

The Golden Lace Nudibranch Is Like A Snail Without A Shell

On land, we think of slugs as basically snails that do not have a shell. But this underwater anomaly, the golden lace nudibranch, is a type of mollusk that has a shell early in life but then sheds it. So it is basically like the part of a mussel that you eat, but it lives most of its life without the hard armor that the shell of a mussel provides.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Imgur

So, in other words, nudibranch mollusks are nude. They live in Hawaii at relatively shallow depths, about 30 feet underwater. They are also quite small, maxing out at about five centimeters in length. Despite their small size, they are carnivores that feed on soft organisms, such as sea sponges. 

Otherwordly Sea Creatures People Rarely See
This cold-water creature is not quite a true jellyfish.

Arctic Hydromedusa Are Not Like The Mythological Medusa

The mythological Medusa was a beautiful woman who was transformed into a monster with snakes for hair; anyone who looked at Medusa would turn into stone. The story is nice and lends itself to the snake-like tentacles that emerge from the “head” of this would-be jellyfish.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Pinterest

The Arctic Hydromedusa (water medusa) looks a lot like a jellyfish and propels itself through the frigid Arctic waters the way that a regular jellyfish would. What distinguishes this particular creature from a true jellyfish is how they produce their eggs. 

Otherwordly Sea Creatures People Rarely See
These massive creatures are a delicacy in Japan.

Japanese Spider Crabs Are Enormous Underwater Scavengers

Japanese spider crabs look like a cross between a crab and a spider, or more accurately, an acromantula from the Harry Potter series. They live off the coast of Japan and grow up to be 12 feet long! Imagine swimming on the beach and coming across a spider-like crab of that size.

Otherwordly Sea Creatures People Rarely See
Photo Credit: The Living Planet

However, the stalwart Japanese people are not afraid of these undersea monsters. They enjoy eating them as a delicacy. Furthermore, the Japanese spider crab serves an essential purpose in its underwater ecosystem: it is a scavenger that feeds on the bodies of dead marine animals. So it is a living underwater filter that helps keep the ocean clean.

Otherwordly Sea Creatures People Rarely See
This sea creature is the only one of its kind ever discovered.

The Hydrothermal Vent Snail Has An Iron Foot

Hydrothermal vents create extreme conditions. Underwater magma chambers heat the water, and the temperatures can reach more than 750 degrees Fahrenheit. Furthermore, the creatures who cannot only live but thrive in these conditions are truly exceptional.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Ocean Explorer Noaa

Take the hydrothermal vent snail, a creature that can take iron sulfide from the water and construct a shell of iron. But this creature does not stop there. Its foot – the part that comes out of the shell – is also covered with the same kind of armored plating as its shell.  

Otherwordly Sea Creatures People Rarely See
This features on this blue-green fish resemble Maori war paint.

The Napoleon Wrasse Is An Underwater Hermaphrodite

According to the Census of Marine Life, “Exceeding two meters in length, the Napoleon Wrasse (Cheilinus undulatus) is one of the largest reef fish found in the warm waters of the Indian and Pacific oceans. The intricate blue-green design that decorates the face resembles New Zealand Maori war paint, the root of its alternative name, the Maori Wrasse.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Hakai Magazine

The designs are also unique to each individual, much like fingerprints. A protogynous hermaphrodite, this wrasse can change its sex from female to male.” So this fish is about as long as a grown human male, resembles people from an indigenous tribe from New Zealand preparing for war, and changes from male to female.

Otherwordly Sea Creatures People Rarely See
This little guy can blend in with just about any environment.

The Lizard Island Octopus Has Mastered The Art Of Mimicry

One feature common to octopuses is that they have chromatophores that allow them to blend in with their background. The Lizard Island octopus has chromatophores on steroids because it can blend in with a larger number of backgrounds than many of its relatives. It is one of the few animals that can imitate another animal to evade a predator!

Otherwordly Sea Creatures People Rarely See
Photo Credit: Pinterest

The term Lizard Island octopus derives from this creature’s home turf, or instead home surf, Lizard Island, part of Australia’s Great Barrier Reef. The octopus is relatively small compared to some of its relatives, usually only about two feet across. 

Otherwordly Sea Creatures People Rarely See
We don’t know much about this strange arthropod.

Metapseudes Lives In Corral Rubble Off Of Australia

There are more arthropods on the planet than species from any other phyla, so, understandably, there are plenty of arthropods that we do not know much about yet. There are probably several arthropods still waiting to be discovered.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Gcrl

The metapseudes is one of these mysterious arthropods about which we know very little. The sea creature lives off of Western Australia among old coral, much of which has died. It has a strange appearance, and marine biologists don’t know why. They also don’t know what it does.

Otherwordly Sea Creatures People Rarely See
This little guy lacks the protective coating of other crustaceans.

The Delicate Claw Lobster Is Quite Delicate

When you think of crustaceans, you probably think about creatures with a shell that covers a soft body. Consider crabs, lobsters, and shrimp, to name just a few. Moreover, for those who eat crustaceans, you know that you have to get the meaty flesh out of the shell.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Youtube

But the poor delicate claw lobster lacks this protective coating. It swims through the water, a forlorn, delicate creature who might be easy prey for anything else swimming. It has a pronounced claw, like other crustaceans, but how much good can that claw do if it is a squishy piece of flesh?

Otherwordly Sea Creatures People Rarely See
Lyssianasid amphipod is a shrimp-like creature in the frigid Antarctic waters.

Some Shrimp Live 600 Feet Underwater In Antarctica

Most of the world’s shrimp live in warm waters, in areas like the Gulf of Mexico that borders the southern states of Florida, Alabama, Mississippi, Louisiana, and Texas, on to the eastern border of Mexico. However, unexpectedly, scientists have found a shrimp-like creature that lives in one of the coldest environments on the planet.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Wikipedia

Lyssianasid amphipod lives 600 feet underwater in the remarkably cold waters off of Antarctica. Scientists have known for quite a while that single-cellular organisms, known as extremophiles, can live in this harsh environment. That a multi-cellular organism would be found there was truly astonishing.

Otherwordly Sea Creatures People Rarely See
Fewer of 50 of these sharks have been seen in over a century.

Goblin Sharks Live Up To Their Name

What has a giant nose, razor-sharp teeth, and is very rarely seen by humans? If your answer is a goblin, you are pretty close. The goblin shark, aptly named for its large nose-like feature and ferocious teeth, has been spotted fewer than 50 times since it was first discovered in 1898.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Quentin Eudeline Artstation

These mysterious sharks are known to grow to at least 15 feet long, though there is no telling what length they max out at least with so few sightings. We do know that they are fierce carnivores that can move their jaws outwards to swallow prey. We’re pretty okay if we never see one of these things in real life.

Otherwordly Sea Creatures People Rarely See
The frilled shark is a living fossil.

Frilled Sharks Come With No Frills

Is Shark Week your favorite week of the year? If so, you may know that sharks are some of the oldest creatures in the world. They are terrifying and attack a minimal number of humans each year, usually mistaking them for seals and other prey.

Otherwordly Sea Creatures People Rarely See
Photo Credit: Amazing Zone

The frilled shark, so named for its, well, frilly structures on its teeth and head is one of the oldest kinds of sharks around. It has changed very little since prehistoric days, so it is a living fossil. Seeing one of these sharks is like getting a glimpse into the ocean’s deep (no pun intended) history.


“35 Utterly Weird Sea Animals,” by Dan Shapley. Popular Mechanics. October 1, 2019.

“These Dangerous Sea Creatures Actually Exist,” by Taylor McAdams. Ninja Journalist. September 17, 2019.

“The 10 Weirdest Ocean Creatures – And Where to Find Them,” by Florida Tech Marketing and Communications. Ad Astra. June 6, 2017.