With 70% of the Earth covered by water and only 5% of that having been explored, it is little wonder that the waves beneath us are often filled with freaky creatures that we know nothing about. Every so often one of these strange beasts will turn up and people will become intrigued by them, instantly setting about to research them. Here we look at some of the freakiest sea creatures that you probably didn't know about.
1. Sea Pig
Related to the sea cucumber, the sea pig has many stubby, tube-like appendages, that it uses to walk along the seafloor, that are filled with hydraulic pumps that fill with water, drawing in sustenance from the food it absorbs off of the ground through the mud that it picks up along the way. Known scientifically as Scotoplanes, their round, trotter-esque, legs and plump appearance has gained them the name sea pigs.
Living at the bottom of deep oceans, they are often killed by deep-sea trawlers that can kill up to 300 of them in one sweep and are a serious threat to them, and thus, the ecology of these environments.
2. Deep Sea Hatchet Fish
Only coming out at night, these elongated fish have freakishly large, bulging that seem out of proportion to the rest of their four-inch bodies and these are used to hunt for food above them in the dark. With bioluminescent photophores on their underbelly, these are used to match the light coming from above them so that they are not silhouetted against the surface and can't be easily spotted by prey beneath them.
Some species have been found to have transparent body parts to allow more light through and they are lined with blade-like fins for defense.
A gelatinous fish that lives in the deep waters of Australasia, these gooey beasts appear so deflated because they lack muscles and so are often carried about by the tides hoping that food will drift to them rather than hunting it themselves. Typically no larger than 30cm long, they lack muscles because of the pressure of where they reside which is 60 to 120 times as great as at sea level.
Voted the World's Ugliest Animal in 2013, it is feared endangered due to deep sea trawling.
4. Glaucus Atlanticus
The Glaucus Atlanticus or Blue Glaucus is a type of sea slug that has finger-like fins that help it move in water. picking it up can result in a very nasty sting. Also known as a sea swallow, blue angel, blue glaucus, blue dragon, blue sea slug and blue ocean slug, the creature is not actually poisonous itself but feeds on such things as the venomous siphonophore, the Portuguese man o' war and stores their poison in its cells in order to use as a defence.
Reaching around 3cm in length, the slug drifts in water and has a blue topside and silver underside so as to remain camouflaged in its watery surroundings. Picking one of these up could result in a nasty, and potentially dangerous, sting.
5. Christmas Tree Worms
Named for their fir-tree like appearance as they reside on deep sea surfaces such as rock or coral and display their brightly colored hair-like appendages in order to both breathe and attract phytoplankton and other prey which they then feed upon. Found across the tropical oceans of the world, they can secrete a calcareous tube which they then use as shelter and protection.
Very few other creatures are known to feed on these worms and so their bright colors are no problem for them in terms of attracting predators.
6. Flamingo Tongue Snail
With a solid white shell, these snails grow to around 1.5 inches in length and cover their shells in a brightly colored membrane that helps them breathe. This can be retracted if the snail is attacked so that only its hard, protective shell remains exposed. A mistake made by many snorkelers and divers is that the colors are from the shell and the creature inside must have departed and so they are collected by accident which has contributed to them becoming rather uncommon.
Living off of toxins secreted by certain corals, such as sea fans, they scrape the polyps off of the coral and often leave feeding scars where they have been.
7. Dumbo Octopus
The Grimpoteuthis is better known as the Dumbo Octopus because of its ear-like fins that stick out above its head, helping it to maneuver in water. Found living at extreme depths of 3,000 to 4,000 meters (9,800 to 13,100 ft) with some living up to 7,000 meters (23,000 ft) below sea level which is the deepest of any known octopus.
Extremely rare, they have been found across the globe and often hover above the sea floor waiting to pounce on prey which they will swallow whole.
8. Goblin Shark
This pink-skinned, deep sea shark has a long, flat protruding snout and highly protrusible jaws. With a lineage of around 125 million years, it is basically a living fossil. It's long nose-like plate can actually sense electrical activity produced by prey that it hunts along the sea floor. Very rare, these creatures are rarely caught or sighted.
Found in all three major oceans, its distribution is not entirely known due to its rarity but it is thought to be widespread.
9. Vampire Squid
With glowing eyes and the tips of its arms, this squid hunts in the dark and uses its bioluminescence to distract predators and prey alike with its bright, confusing flashes of light. Its arms are all connected together with a thin layer of webbing and when threatened it covers its head with its arm revealing razor-sharp spines that are like teeth, in a defensive maneuver.
It has blue blood due to the lack of oxygen at low pressures and does not spray ink but rather disorientating clouds of glowing mucus, but this rarely happens as it takes a lot of energy to regenerate that afterward so only occurs under extreme threat.
Known as Mexican salamanders, axolotls are unusual among amphibians in the sense that they do not undergo metamorphosis to reach adulthood and as such, forever remain in a state of youth where they remain aquatic and gilled in a middle stage of metamorphosis that is never followed by a final stage.
What is of further interest is that, although reaching sexual maturity without metamorphosis, if injected with iodine, the axolotl will metamorphose into something akin to a tiger salamander. They also have the ability to regenerate whole limbs.
With teeth so large that they can't actually fit into its mouth, they protrude upwards towards its eyes in an intimidating sight, the viperfish has an elongated photophone that it lights up to attract prey towards it in the darkness of the deep waters before snapping them up with its hinged lower jaw which it has to use because it can not bend its teeth back into its head.
Elongated and covered in an unknown substance to science, they reflect light to confuse predators and can live up to 30 to 40 years in the wild but have only been known to live for a few hours when captive.
The male anglerfish is incredibly small and weak and with few discerning features bar an incredible sense of smell which it uses to hunt down females before biting them. The females, far larger and with a bioluminescent rod on the top of their heads called an escra, then secrete a toxin that glues the male to her and slowly kills it off except for the use of its testicles which she then uses to fertilize herself.
Some anglerfish have been known to be able to have several males attached to them whilst they lure prey to them with their glowing escra.
13. Peacock Mantis Shrimp
The mantis shrimp is a water crustacean that can come in vivid colors and are known to be aggressive, solitary creatures which seems odd since they look like they want a bit of attention. Some of the largest specimens can break aquarium glass by striking it, and can do further damage by burrowing in live rock.
With a voracious appetite, they can break through rock in order to burrow into it and have been known to sneak into aquariums via rock and eat the other inhabitants.
14. Red-Lipped Batfish
Not particularly adept at swimming, this fish leaps around on the ocean floor around the Galapagos islands using its adapted pectoral fins to launch itself off the ground. On top of the batfish's head is an extendable part called an illicium that it uses to lure prey towards them much like angler fish as the tip of the illicium lights up and draws smaller prey in.
Harmless to humans, their red lips distinguish them from other types of batfish during breeding seasons.