Most Bizarre Marine Animals in the World
Believe it or not, humans have only explored about 5% of the ocean. In fact, we know more about the surface of Mars, a planet millions of miles away, than we do about our very own seafloor. Despite how little we know, researchers have managed to stumble upon thousands of bizarre aquatic creatures that belong in the trippiest sequences in Tim Burton’s Alice in Wonderland (2010).
If you want to see just how strange sea life gets, there’s no deep-diving necessary. Check out our list of the most bizarre marine animals in the world.
Ornately camouflaged, this little fish has thin, leaf-like appendages stemming from its body. Although it seems like a video game designer created a fun combination of a seahorse and an office plant, the leafy seadragon isn’t a character from the Pokémon universe. The leaf-shaped protrusions have a purpose and help this creature blend in with the kelp formations it calls home.
The bioluminescent octopus looks like it just stepped onto the Grid in Tron: Legacy (2010), ready to mount a light cycle. But this glow isn’t part of a costume. Much like a firefly, a chemical reaction occurs in this organism’s body, creating that otherworldly glow — or bioluminescence. The blue-green light forms in the 40 or so suckers, or photophores, that run along the octopus’ underarms.
These krill-eating fish live in the warm waters of the Carribean Sea and the southwestern part of the Atlantic Ocean. Because they live around the edges of coral reefs, there’s not much to shelter these fish, which is probably why nature got creative. Using their large, gaping mouths, jawfish dig into the sand and build burrows.
Ah, the blobfish: part-meme, part-Grumpy-Cat-of-the-sea, and part-Kate McKinnon character. Called everything from "Mr. Blobby" to "a Botoxed potato," this creature infamously won the title of earth’s most hideous species in an online poll. Sure, this gelatinous lump looks more like a gummy candy left in the hot sun than a fish, but the blobfish is also one of Earth’s most misunderstood species.
Turritopsis Dohrnii (“Immortal” Jellyfish)
Known by researchers (and Latin enthusiasts) as Turritopsis dohrnii, the Immortal Jellyfish (as we commoners call it) is bizarre in more than just looks. In fact, this jellyfish nabs a spot on our list instead of others of its ilk because it doesn’t have a lifespan — hence, the whole immortality thing. At any moment, this jellyfish can just press the proverbial restart button.
Kiwa Tyleri (“Yeti” Crab)
Thankfully the yeti crab isn’t named for its towering height. Instead, it looks more like the Abominable Snowman’s pet. This particular type of hairy-chested yeti crab was found off the coast of Antarctica in 2010, five years after the discovery of two other species of yeti crab. This fuzzy-looking crustacean lives in the harshest environment of all.
One is the loneliest number, especially if you’re going solo in the desolate, lightless bottom of the sea. Looking understandably irritated, the anglerfish knows this better than any other organism. Although some lucky anglers live closer to the surface in tropical environments, most swim around in the murky waters of the Atlantic and Antarctic oceans, roughly a mile below the surface.
The largetooth sawfish puts the swordfish to shame — or at least is a bit more unsettling. Growing up to 21 feet in length, these shark-like creatures are actually a type of ray. As you might imagine, that toothed snout is used to find and capture prey, but, unfortunately, this useful feature has its downside.
Native to the waters off the Galápagos Islands and Peru, the red-lipped batfish always seems a bit shocked, as if you’re constantly rushing it out of the bathroom before a big night on the town. The fish has that hands-gripping-the-vanity, shocked to running late look. In reality, the red-lipped batfish isn’t rushing off anywhere because it’s not a good swimmer. Instead, the pectoral fins of this creature help it "walk" along the ocean floor.
The scientific name for this next creature is Vampyroteuthis infernalis — which translates to "vampire squid from hell." Even though the name evokes horror at its finest and most gruesome, this cephalopod isn’t too terrifying. It features characteristics from both octopuses and squid, but it doesn’t have some of their more definitive traits. For example, its muscles can’t control changing color, nor can it excrete ink. However, it does have a few somewhat creepy features.
Terrible Claw Lobster
With one smaller, toothed claw and one more frightening, elongated one, this deep-sea crustacean looks a bit like a cross between a lobster and your trusty pocket knife. But there’s no need to worry. This little creature probably won’t do much damage if you encounter it — it’s only an inch and a half long on average. Discovered back in 2007 in waters near the Philippines, the reason this lobster has such a specialized claw still evades scientists to this day.
Flamingo Tongue Snail
Contrary to the image conjured by its name, the flamingo tongue snail isn’t always bright pink. Although a pink coloration is possible, this small marine snail is perhaps better known for its bright orange hues and black spots. (This makes us think leopard snail would be a better name, although neither seems especially fitting.) Surprisingly, the lively colors aren’t part of the snail’s shell, but rather the soft tissue of its body, which is often wrapped around the shell’s exterior.
Christmas Tree Worm
Christmas tree worms aren’t named after the thing they eat, so you can continue to deck the halls without fear. Instead, these marine animals are named for the tree-shaped crowns that protrude from their tubelike bodies. Brightly colored and made up of hair-like features called radioles, these crowns come in pairs, making it look like two Christmas trees are blooming from the worm’s body.
This deep-sea fish derives its name from its flattened body shape, which resembles the blade of a hatchet. You may think you recognize this particular fish, but the marine hatchetfish is different from the freshwater hatchetfish, which you can often find floating around in your local aquarium. Although freshwater hatchets look fairly innocuous, the marine hatchet isn’t something you’d want to bump into in the deep.
This deep-sea "umbrella" octopus was named after its fins, which resemble the infamously large ears of Disney’s loveable pachyderm, Dumbo. This creature’s arms are all connected by a web of skin, making it look like an open umbrella when its arms are spread. This combination of features allows them to move through the depths of the ocean with ease. By flapping its ear-like fins, the dumbo octopus pushes its body through the water and then uses its arms to steer.
Pycnogonida Sea Spider
Sea spiders are found in the Mediterranean and Caribbean seas as well as in the Atlantic and Arctic oceans. They look quite a lot like land spiders — or maybe a mix of land spiders and crabs — but they’re often much larger. (Unless, of course, you’re comparing them to Australia’s plethora of larger-than-average spiders.) Sea spiders can grow to be nearly 3 feet long and weigh as much as a pound. Yikes!
Googly-Eyed Stubby Squid
The googly-eyed stubby squid looks like something you made in an arts and crafts session at summer camp — or maybe like a cheap, rubber toy you got out of a vending machine at the local bowling alley. Just look at those eyes; they almost seem painted on. Despite the strangeness of this creature, its cuteness is undeniable. When scientists spotted one off the coast of California in Monterey Bay for the first time, they couldn’t stop giggling. And who could blame them?
Venus Flytrap Anemone
Found mainly in the deep water canyons of the Gulf of Mexico, the Venus flytrap anemone is strangely mesmerizing. Maybe it’s because it resembles its terrestrial namesake so closely, or maybe it's the hypnotic way it sways in the water. With a stem-like body and disk-shaped mouth, the Venus flytrap anemone — like other anemones — looks a lot like a flower.
The origin of the fangtooth’s name certainly isn’t a mystery. Although many deep-sea fish seem to have a terrible underbite — not sure how that helps them survive the dark, but that’s okay — the fangtooth certainly has the most unhinged jaw. Thanks to their gaping mouths and rows of long, pointed teeth, the fangtooth is great at snatching prey that drifts through the ocean’s depths.
There are about 3,000 different species of nudibranchs — and all of them are wild looking. The regal sea goddess nudibranch (pictured) definitely ranks up there among the strangest-looking (and the best-named). These soft-bodied mollusks, which are commonly called "sea slugs," shed their shells after they grow out of their larval stage, revealing a mix of beautiful colors. Although their name is meant to be all-encompassing for a wide-range of creatures, the term nudibranch is also incredibly apt, as it comes from a combination of Latin and Greek words that mean "naked gill."
The whitemargin stargazer is aptly named: It burrows into the sea floor, leaving only its wide eyes — situated on top of its head — exposed to the surface. Of course, the stargazer isn’t actually interested in astronomy. Instead, it gazes up, looking for prey to snatch and, in classic ambush-style, grabs anything that swims by.
Frogfish are actually members of the anglerfish family but live in most tropical climates. Most types are covered in spinules or other appendages that look a bit like kelp, seaweed or coral. These features help them camouflage more easily, a tactic they rely on not only to hide from would-be predators, but also to surprise their own prey. By blending in and moving slowly, frogfish can pull a fast one on prey — so fast, in fact, that scientists estimate a frogfish snatches its victim in about 6 milliseconds.
With a flat head and stocky body perfectly designed to lie on the seafloor, the ornate wobbegong is actually a type of carpet shark. Like other marine camouflage enthusiasts, it operates as an ambush predator and will wait around the algae-covered rocks in bays or in the shallows surrounding coral reefs until prey passes close enough to attack.
The box jellyfish is most known for its deadly venom. If you’ve ever visited a beach in Australia — particularly any northern beaches during the wet season — you’ve probably seen signs that warn visitors of the presence of this lethal creature. Dubbed the most venomous marine animal known to mankind, even the box jellyfish’s nicknames — sea wasp and fire medusa — should be enough to keep you miles away.
Surprise, surprise — the boxfish is box-shaped. Its body is also very tough and rigid, almost like an armor. In theory, the distinct shape and plated body could seem a bit detrimental to the fish’s ability to move, but this creature has found a way around all that. Its style of swimming is known as ostraciiform locomotion, which is a fancy way of saying the fish’s tail does the bulk of the work.
Hydrothermal Vent Snail
To those in the know, the hydrothermal vent snail is also known as the scaly-foot gastropod, a name that makes it sound a lot more off-putting and bizarre. This marine mollusk makes its home on hydrothermal vents found in the Indian Ocean at depths of about 2,500 feet below the surface. Because the vents it calls home are rich in metal ores, the snail was placed on the endangered list in 2019, making it the first species to be declared endangered due to deep-sea mining.
Native to the Indo-Pacific, the carnivorous lionfish is now an invasive species that has infiltrated the Atlantic Ocean. You may recognize this feisty fish from home aquariums — after all, those intricate fins are something to marvel at — but they are less fun to look at when they’re wrecking natural reefs. As the name suggests, lionfish are a top predator, and this has had lasting effects on the delicate ecosystems of coral reefs.
Japanese Flying Squid
Native to the waters off Japan, China, and Russia, the Japanese flying squid has now moved across the Bering Strait to the waters off Alaska and Canada as well. These small squid that only live for about a year are known for their ability to fly. You read that correctly — these marine animals take to the skies on occasion.
Venture with us back to Australia’s Great Barrier Reef for a look at another deadly creature. The stonefish is known as the world’s most venomous fish, so between that and the box jellyfish, we’re not sure surfing in Australia is worth the risk. Using its dorsal fin spines, this creature can inject a victim with enough venom to kill an adult human in less than an hour.
Asian Sheepshead Wrasse
With the ability to grow more than 3 feet in length, the Asian sheepshead wrasse is one of the largest of its species. It lives in the western Pacific Ocean, swimming off the Korean Peninsula, China, and Japan. Its most striking feature? Well, that can’t easily be narrowed down to just one element. After all, its unusually bulbous chin has a giant forehead to match. Young wrasses, which are orange in color, don’t have these protrusions, which gives a whole new meaning to "growing into" your facial features.