Deep-Sea Discoveries: Unveiling the Weirdest Deep-Sea Creatures
The deep sea is a mysterious world filled with bizarre and fascinating creatures that have adapted to survive in extreme conditions. With the absence of sunlight, frigid temperatures, and crushing pressure, these deep-sea dwellers have evolved unique traits that make them truly alien-looking. From light-producing organs to gigantic mouths and mismatched eyes, the deep sea is teeming with creatures that have captured the imagination of scientists and enthusiasts alike.
Scientists define the deep sea as encompassing all ocean waters below 656 feet (200 meters). In these regions, sunlight filtering through the water from above begins to dwindle, giving way to a realm of complete darkness, frigid temperatures, and crushing pressure. Some of the deepest-dwelling animals have adapted to the abyss by adopting light-producing organs to attract prey or signal to each other. Others have evolved gigantic mouths, expandable stomachs, or mismatched eyes. Regardless of their specific traits, deep-sea creatures have captured the imagination of many people due to their otherworldly — and often nightmarish — appearance.
Thanks to much exploration over the past few decades, scientists have described quite a few of our deep-dwelling neighbors. So, without further ado, here are 32 of the weirdest creatures that inhabit the deep ocean.
### Snipe Eel: The Beak-Like Jaws of the Deep
Snipe eels (family Nemichthyidae) have beak-like jaws and slender bodies. They are found at depths between 980 and 2,000 feet (300 to 600 m), although some individuals have been hauled up from 14,800 feet (4,500 m) deep. Relative to their size, snipe eels have large eyes, which the eels use to avoid predators. Their jaws are curved upward and remain open as they swim so the eels can snatch prey on their path. Snipe eels can grow up to 6.6 feet (2 m) long, depending on the species. Nine species have been described so far.
### Frilled Shark: A Living Fossil of the Deep
The frilled shark (Chlamydoselachus anguineus) gets its name from the frilly appearance of its gill slits. This deep-sea shark has an elongated, eel-like body that grows up to 6.6 feet (2 m) long, as well as a large, flattened head. It is found worldwide and swims by undulating its body like a snake. The frilled shark is an active predator with several rows of needle-sharp, three-pointed teeth, which it uses to rip up its favorite meal of squid, as well as fish and other sharks. Researchers rarely encounter frilled sharks, prompting them to think the species is distributed in patches of the deep ocean.
### Giant Sea Spider: The Arctic and Antarctic Lumberer
Giant sea spiders (Colossendeis) have spindly legs that can stretch wider than a dinner plate. They live on the Arctic and Antarctic ocean floor down to depths of 13,100 feet (4,000 m), where they lumber along in search of food and mates. Like other sea spiders, they share a common ancestor with spiders and crabs but have been evolving as a separate group for hundreds of millions of years. Giant sea spiders house their vital organs, including their breathing apparatus, in their stilt-like legs. Instead of spinning a web as terrestrial spiders do, they use a long, tubelike mouthpart to slurp up prey, including anemones, worms, jellies, and sponges.
### Gulper Eel: The Pelican of the Deep
Gulper eels (Saccopharynx), also known as pelican eels, are a genus of deep-sea fish with slender bodies and huge mouths that swing open to swallow prey of all sizes whole. They are found throughout the world’s oceans in the twilight zone, which stretches between 660 and 3,300 feet (200 to 1,000 m) deep, and the midnight zone, which extends between 3,300 and 13,100 feet (1,000 to 4,000 m) below the surface. The whiptail gulper eel (Saccopharynx lavenbergi), for example, lives 980 to 6,600 feet (300 to 2,000 m) deep in the Eastern Pacific Ocean. This eel grows to about 3.3 feet (1 m) long and feeds mainly on small fish. It swims by undulating its body, which has a glowing tip that scientists think might act as a bioluminescent lure to attract prey.
### Cookiecutter Shark: Taking a Bite Out of the Deep
The cookiecutter shark (Isistius brasiliensis) is a small, cigar-shaped shark that latches onto prey of all sizes and uses its serrated bottom teeth to carve out circular chunks of flesh. Cookiecutter sharks grow to between 16.5 and 22 inches (42 to 56 centimeters) long. They live in tropical and temperate oceans worldwide, inhabiting depths below 3,300 feet (1,000 m) during the day and migrating up to surface waters at night to feed. Although cookiecutter sharks are generally harmless to humans due to their deep-water habitat, four people have reported unprovoked bites off the coast of Hawaii.
### Dumbo Octopus: The Deep-Sea Elephant
There are 17 species of dumbo octopus (Grimpoteuthis), which are named after Disney’s lovable elephant character. These octopuses, which belong to the larger umbrella octopus family Opisthoteuthidae, have two ear-like fins extending from above each eye. Like other umbrella octopuses, dumbo octopuses have webbing between their arms that spreads out to look like an umbrella. Dumbo octopuses are the deepest living of all known octopuses, inhabiting ocean depths of at least 13,100 feet (4,000 m). In 2020, scientists filmed a dumbo octopus 22,825 feet (6,957 m) below the surface of the Indian Ocean. Dumbo octopuses measure about 8 inches (20 cm) tall and swim by gently flapping their “ears.” They use their webbing to hover over the seafloor while searching for food, including snails and worms.
### Viperfish: The Needle-Toothed Predator of the Twilight Zone
Deep-sea viperfish (Chauliodus) have needle-like teeth that they can open wide enough to engulf prey and close again to form a cage-like trap. Most species of viperfish inhabit the twilight zone, between 660 and 3,300 feet (200 to 1,000 m) deep. Viperfish typically grow to about 12 inches (30 cm) long. Some species, including the Sloane’s viperfish, have light-producing organs on their bellies, which they use to blend in with the 1% of light that penetrates waters below 660 feet.
### Goblin Shark: The Alien-Looking Predator of the Deep
The goblin shark (Mitsukurina owstoni) is a large, alien-looking shark with a shovel-like snout and a mouth it uses to lurch at and snatch prey. Little is known about goblin sharks, except that they live in deep waters along continental slopes and seamounts. The deepest recorded individual was hauled up from 4,265 feet (1,300 m) deep. Scientists think goblin sharks hunt prey, such as squid and crustaceans, by detecting changes in electric fields. Once the sharks are close enough, their jaws shoot outward to gobble up the unsuspecting animal.
### Siphonophores: The Colonial Creatures of the Deep
A siphonophore (order Siphonophorae) is a colony of genetically identical polyps, or zooids, that acts like one organism. Siphonophores can grow to extraordinary lengths, with the giant siphonophore measuring 154 feet (47 m) long and 49 feet (15 m) in diameter. Scientists have named more than 175 species of siphonophore, including deep-sea colonies that glow green, blue, and sometimes red to attract prey. The giant siphonophore (Praya dubia) is a bioluminescent creature that turns bright blue when it bumps against other objects and animals. It lives between 2,300 and 3,300 feet (700 to 1,000 m) deep.
### Greenland Shark: The Longest-Lived Vertebrate of the Deep
The greenland shark (Somniosus microcephalus) is an extremely long-lived shark species that inhabits North Atlantic and Arctic waters down to depths of about 4,000 feet (1,200 m). Researchers estimate that Greenland sharks live at least 250 years and possibly more than 500 years, making them the longest-lived vertebrates known to science. Greenland sharks can grow up to 24 feet (7.3 m) long. People in northern regions hunt these sharks for their meat and skin, which can be used to make leather. The flesh is poisonous when eaten raw, but it becomes edible when it is dried.
### Sea Pig: The Pink Feeder of the Deep
Sea pigs (Scotoplanes) are a group of deep-dwelling sea cucumbers that have stilt-like tube feet on their bellies. They use their tube feet to weed through muddy sediments in search of food, such as bits of algae and dead animals that have fallen to the seafloor. Sea pigs grow to between 1.5 and 6 inches (4 to 15 cm) long and live down to depths of 22,000 feet (6,700 m). The rosy sea cucumbers sometimes gather in huge herds to feast on the sunken carcasses of large animals, like whales.
### Goosefish: The Ambush Predator of the Ocean Floor
Goosefish (Lophiidae) are a type of anglerfish (Lophiiformes), known for attracting prey with a luminescent lure and having “accessory” males that provide a constant supply of sperm to females. Goosefish are usually found on sandy or muddy ocean bottoms more than 3,000 feet (910 m) deep, where they blend in thanks to speckled patterns on their back. Like other anglerfish, a goosefish entices prey — including fish, crustaceans, and sea stars — with a lure that dangles from the top of its head. Goosefish can also relocate by “walking” on their pectoral and ventral fins, which have modified joints so they can pivot and be used like feet.
### Brier Shark: The Long-Nosed Predator of the Deep
The Brier shark (Deania calcea), also known as the birdbeak dogfish, is a shark that’s usually found between depths of 2,000 and 3,300 feet (600 to 1,000 m). Brier sharks are widely distributed off of Australia’s southern coast, across the eastern and western Pacific Ocean, and in the eastern Atlantic Ocean. Brier sharks grow up to 3.9 feet (1.2 m) long and are thought to reach a maximum age of 35 years. They are mostly caught accidentally as bycatch, although some fisheries target the sharks for their flesh and liver oil.
### Bigfin Squid: The Elusive Giant of the Deep
Bigfin squid (Magnapinna) are a genus of rarely seen squid that can grow up to 20 feet (6 m) long — mostly thanks to their trailing arms and tentacles, which can extend 20 times longer than the squid’s body. As the name suggests, bigfin squid have large fins protruding from their mantle. They are the deepest-dwelling squid known to science, gliding down to depths of more than 20,000 feet (6,000 m). It’s unclear why bigfin squid have such long arms and tentacles, but scientists think the appendages are covered in microscopic suckers that can trap prey as the squid swim. Only a dozen or so sightings of bigfin squid have been recorded, with three species documented across the world’s oceans so far.
### Black Seadevil Anglerfish: The Deep-Sea Parasitic Lover
The black seadevil anglerfish (Melanocetus johnsonii) has a luminescent, pole-like lure on the top of its head and lives between 330 and 15,000 feet (100 to 4,500 m) below the ocean’s surface. Females grow up to 8 inches (20 cm) long, while males reach only around 1 inch (3 cm) in length. Black seadevil males only act as parasitic, sperm-producing accessories for females. When a male finds a suitable female mate, he latches onto her and fuses his skin and bloodstream with hers for life, feeding off the nutrients she ingests.
### Purpleback Flying Squid: The Speedy Predator of the Tropics
The purpleback flying squid (Sthenoteuthis oualaniensis) is a widely distributed species that lives down to depths of 3,300 feet (1,000 m) in the tropical and subtropical waters of the Indian and Pacific oceans. Purpleback flying squid come in five sizes, ranging from dwarf to giant. They are powerful swimmers and can reach speeds of 22 mph (35 km/h). Fisheries in Japan and Taiwan target purpleback flying squid to use as bait for tuna, as well as for human consumption.
### Giant Isopod: The Scavenger of the Deep Ocean Floor
The giant isopod (Bathynomus giganteus) is the largest of all isopods, measuring up to 16 inches (40 cm) from head to tail. Giant isopods roam the seafloor, scavenging food that falls from above, such as fish carcasses. They can also swim short distances using their fan-like tails. Giant isopods are an example of deep-sea gigantism, an evolutionary pattern in which deep-dwelling creatures grow much larger than their relatives in other habitats. Deep-sea gigantism may result from a lack of predators in the ocean’s deepest corners and/or from the need for organisms to carry more oxygen at great depths.
### Bloody-Belly Comb Jelly: The Scarlet Camouflage of the Abyss
The bloody-belly comb jelly (Lampocteis cruentiventer) is a jellyfish species that inhabits depths between 820 and 4,900 feet (250 to 1,500 m). The red stomach of the bloody-belly comb jelly helps it blend in with its dark surroundings. The red is particularly prominent on the jelly’s belly to conceal any luminous prey it may have ingested. The bloody-belly comb jelly’s sparkling displays of light running along its body result from light bouncing off tiny, hair-like filaments that propel the jelly through the water column.
### Black Swallower: The Expandable Predator of the Deep
The black swallower (Chiasmodon niger) is an elusive fish species found at depths between 2,300 and 10,000 feet (700 to 3,000 m) in temperate and tropical Atlantic waters. It has a dark, scaleless body and a large mouth, and it grows up to 10 inches (25 cm) long. The black swallower also has a long lower jaw and an expandable stomach, enabling the fish to gulp down prey up to four times its length and 10 times its weight. Very few people have seen a black swallower in the deep sea, according to the Woods Hole Oceanographic Institution.
### Vampire Squid: The Dark Feeder of the Deep
The vampire squid (Vampyroteuthis infernalis) is one of two known living members of a subgroup of cephalopods called Vampyromorphida. Vampire squid live in temperate and tropical waters deeper than 660 feet (200 m) worldwide. Full-grown vampire squid have a body length of around 12 inches (30 cm) and the biggest eyes of any living animal proportional to its body size. Vampire squid feed on floating marine debris, also known as marine snow. When startled, they invert their eight webbed arms to produce a “cloak” that covers their body.
### Lanternfish: The Illuminated Swimmers of the Deep
Lanternfish are small fish in the family Myctophidae, named after the blue-green light organs embedded in their bodies. These light organs help the fish see and signal to other fish in the dark depths of the ocean. Lanternfish range from 0.8 to 12 inches (2 to 30 cm) in length and are known to migrate up to surface waters to feed at night. Their secret light communication powers have made them some of the most successful fish in their habitat, making up 60% of all deep-sea fish.
### Hoff Crab: The Hairy Hydrothermal Vent Dweller
The Hoff crab (Kiwa tyleri) is a species of deep-sea squat lobster that lives near hydrothermal vents in the frigid Southern Ocean. It forms part of a group of squat lobsters called the yeti crabs because they are white and covered in setae, but the Hoff crab stands out as having a particularly furry chest. Like other yeti crabs, Hoff crabs use their hairs to harvest bacteria contained in the scorching liquid that comes out of the vents. They then feed on these bacteria. Surveys have shown that up to 700 crabs can pack into about 10 square feet (1 square meter) of this inhospitable environment.
### Sea Angel: The Swimming Snail of the Deep
Sea angels (Gymnosomata) are a group of swimming snails found down to depths of 2,000 feet (610 m) in cold and temperate waters worldwide. They have gelatinous bodies ranging from 1.5 to 3 inches (4 to 8 cm) long and two winglike appendages called parapodia, which the sea angels flap to propel themselves through the water. Sea angels use two structures called buccal cones to remove their prey of choice — sea butterflies — directly from their shells. Sea angels have translucent skin, allowing for a view of their internal organs, which can have a pink or orange hue.
### Dragonfish: The Luminous Predators of the Twilight Zone
Dragonfish (Stomiidae) are a family of otherworldly creatures that live in the twilight and midnight zones of the ocean down to depths of 14,800 feet (4,500 m). Females grow to around 20 inches (50 cm) long, while males reach between 2 and 6 inches (5 to 15 cm), depending on the species. Both males and females have gaping jaws, but only females have fangs — long, translucent teeth embedded with nanocrystals that give female dragonfish a stronger bite than sharks’. Females also have a luminous barbel that hangs from their chin and attracts prey. Both males and females are covered in light-producing organs called photophores, which the dragonfish use to signal to each other.
### Cockeyed Squid: The Asymmetrical Hunter of the Deep
As its name suggests, the cockeyed squid (Histioteuthis heteropsis) has two eyes that are dramatically different in size and structure. Cockeyed squid are born with
