Many of the most fascinating marine creatures live at extreme depths, where the darkness is absolute and the surrounding pressure is immense.

Five Fascinating Deep Sea Creatures

By Scuba Diver Life

It’s often said that we know less about the ocean than we do about the moon. As most of us know, the ocean accounts for approximately 70 percent of the planet’s surface, and reaches almost 36,000 feet (11,000m) at its deepest known point. Its vastness is almost impossible to comprehend, so it’s no surprise that new marine species are discovered every year. Many of the most fascinating marine creatures live at extreme depths, where the darkness is absolute and the surrounding pressure is immense. It’s the adaptations required to survive in these harsh conditions that make deep-sea creatures so unique.

  • The Blobfish

    By Scuba Diver Life

    Voted the [World’s Ugliest Animal in 2013](http://uglyanimalsoc.com/) because of its flabby form and overly large ‘nose,’ the blobfish is certainly no looker, but there’s a good reason for its strange appearance. The blobfish is found off the coasts of mainland Australia, Tasmania and New Zealand at depths of up to 3,900 feet (1,200m). At such extreme depths, the blobfish cannot depend on a swim bladder for buoyancy, as do shallow-dwelling fish. Instead, its gelatinous flesh is slightly less dense than the water around it, allowing it to easily float a few feet above the seafloor. Not much is known about this odd-looking species, other than that it is often the unintentional victim of deep-sea fishing trawlers. It is thought that they subsist on particles of edible matter floating in the water around them, and grow no larger than 12 inches (30cm). Although it is almost impossible to estimate blobfish populations, it is thought that the species may be at risk as a result of accidental overfishing.

  • Gulper Eel

    By Scuba Diver Life

    Found in the deep waters of all temperate and tropical oceans, the gulper eel inhabits depths of up to 9,800 feet (3,000m). It is also known as the pelican eel because of its enormous mouth, which is bigger than the rest of its body put together, and which allows the eel to swallow and devour food much larger than itself. Prey is thought to include cephalopods and other invertebrates, which it attracts using bioluminescent tentacles located at the end of its long, whip-like tail. The gulper eel grows to approximately 2.5 feet (75cm) long, and stands out from other fish species for its lack of pelvic fins, a swim bladder or scales. Almost all of what we know about gulper eels comes from specimens accidentally caught by deep-sea trawlers, and as such it’s difficult to accurately estimate how many of them there are throughout their range.

  • Giant Isopod

    By Scuba Diver Life

    Considered to be abundant in the deep, cold waters of the Atlantic, the Pacific and the Indian Oceans, the giant isopod is a deep-sea crustacean that resembles the tiny woodlouse or pillbug, also known as a roly-poly, commonly found on land. The isopod is much bigger than its terrestrial counterpart, though, with the largest of almost 20 distinct species boasting a maximum length of 2.5 feet (76 cm). These fascinating creatures are thought to have existed for more than 160 million years, meaning that they lived before the break up of the supercontinent Pangaea. Giant isopods are the scavengers of the deep, and have been found at depths of up to 7,020 feet (2,140m). They are primarily carnivorous, and feed on the flesh of dead whales and other large sea creatures. However, because such food is often hard to come by on the seafloor, giant isopods have been known to survive for more than five years in captivity without food.

  • Frilled Shark

    By Scuba Diver Life

    Found infrequently throughout the Atlantic and Pacific Oceans at depths of up to 5,150 feet (1,570 m), the frilled shark is most fascinating for its reputation as a living fossil. This species belongs to one of the oldest extant shark lineages, thought to exist for approximately 150 million years. Accordingly, the frilled shark has several primitive characteristics including six gills instead of five, and an elongated, eel-like body. The shark’s strange shape has prompted experts to suggest that sea-serpent myths may have stemmed from frilled-shark sightings. This species even acts like a snake in some respects, particularly with regards to the lunging technique that it uses to attack prey. The frilled shark feeds mainly on cephalopods, and at 3½ years, has the longest gestation period of any vertebrate. This incredibly slow rate of reproduction means that it is susceptible to accidental overfishing, and it is categorized as Near Threatened on the IUCN Red List as a result.

  • Fangtooth Fish

    By Scuba Diver Life

    Amongst the deepest-living of all fish species, the fangtooth fish is found in tropical and temperate waters around the globe at depths of up to 16,400 feet (5,000m). Its fang-like teeth are the largest of any fish in the ocean in proportion to its body size. The two fangs of this fish’s lower jaw are so long that it cannot fully close its mouth; instead, this species has two sockets on either side of its head that accommodate the teeth’s sharp points without causing any damage. The fangtooth attains a maximum size of just 7 inches (18 cm), and uses its formidable teeth to target prey much larger than itself. Some scientists hypothesize that fangtooth fish migrate to shallower waters at night in order to feed by starlight, while others believe that they hunt in the darkness using contact chemoreception, i.e., by using touch to locate their next meal. 

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