The deep sea has always fascinated humans. It is a place where only a select few would dare to venture into. In fact, more people have gone into space than into the deep sea. Darkness, cold temperatures, and high water pressures characterize the habitat of the deep sea. At approximately 1000 m below sea level, no light penetrates the ocean waters. At such great depths, the water column above creates so much pressure that it is hard to imagine that any life would survive here. In fact, most life on the surface would be crushed to death at such depths.
However, many sea creatures exist in the deep sea. They have special adaptations that allow them to survive in such habitats. Some of these mysterious, deep-sea creatures have been mentioned below. Many more remain to be discovered by humans.
9. Barreleye Fish
The deep sea is known for its “weird-looking” residents, and the barreleye fish is no exception to that. First described in 1939, the Macropinna microstoma has a transparent head with two upward-pointed sensitive barrel-shaped eyes. It is believed that the see-through head of the fish allows it to collect a little more light to give it a better advantage in the darkness where it lives while its unique eyes allow it to see silhouettes of its prey.
8. Zombie Worms
Zombie worms or osedax are known for their extreme feeding habits. They consume bones including those of the world’s largest creatures, whales. While female zombie worms are about 2 inches long, males are microscopic and live as parasites on the female body. These worms secrete chemicals and carry symbiotic bacteria that help them digest bones and feed on the same. These scavengers are vital to the deep sea habitat as they help clean up the ocean floor.
7. Deep-sea Dragonfish
The deep-sea dragonfish is another deep-sea creature that uses its oversized fang-like teeth to grab prey in the deep, dark environs of its habitat. It is said that the transparent teeth of this fish are stronger than that of a piranha. These fish have slimy, slippery skin, a length of around 15 cm, bioluminescent photophores, and other adaptations to living at great depths. It is found at ocean depths ranging from 200 m to 2000 m.
6. Deep-sea Octopus
The dumbo octopus and the telescope octopus are two octopi found in the dark depths of the ocean. The former lives at depths of at least 4000 m and below. At such great depths, there is hardly any predator and thus the dumbo lack any ink sac. Named after Disney’s Dumbo the elephant character, these octopi actually appear like an adorable character of an animated movie. They usually remain suspended above the sea-floor but forage for invertebrates on the floor. The telescope octopus is another unique animal of the deep sea. It drifts through the ocean at depths of over 2000 m and often remains vertically suspended above the seafloor. The body of this octopus is nearly completely transparent. What distinguishes is most clearly from others of its kind are two protruding eyeballs which provide wide peripheral vision to the animal.
5. Goblin Shark
Another addition to the unusual creatures living in the ocean’s mysterious depths, the goblin shark truly lives up to its name. This pink-skinned, flabby-bodied, and small-finned animal is noted for its elongated, flattened snout. The creature’s highly protrusible jaws with razor sharp teeth make it a highly competitive predator in the dark waters. Crustaceans, cephalopods, and teleost fishes constitute its diet.
4. Deep-sea Jellyfish Benthocodon -
The Benthocodon hyalinus is a unique jellyfish of the deep ocean and is found at depths below 750 m. It has a rounded top called the bell which has a diameter of 2 to 3 cm only. Around 1,500 red tentacles lace the bell and help the jellyfish to maneuver itself in the water. The diet of this jellyfish comprises primarily of crustaceans and tiny unicellular organisms. The opaque reddish color of its bell is believed to protect it from being recognized by its predators. If it was transparent, the bioluminescent glow of the creatures it eats will give away the location of the jellyfish making it susceptible to predation.
3. Pelican Eel
The Eurypharynx pelecanoides is one of the mysterious deep-sea creatures that are rarely seen by humans. It derives its name from its large mouth reminding one of the mouth of a pelican. The loosely hinged mouth of this fish allows it to swallow animals much larger than its size. The pelican eel appears very different from true eels and lacks swim bladders, scales, and pelvic fins. The whip-like tail is used to move in the waters. It has a complex organ at the tail end that generates pink glows in the dark, possibly to attract prey. The pelican eel feeds primarily on crustaceans. It moves into large groups of crustaceans and scoops the creatures in its widely opened mouth. This creature is found at depths ranging from 500 to 3,000 m in both temperate and tropical areas of oceans.
2. Seadevil Anglerfish
The deep ocean is full of wonders and the anglerfish is another one of them. It is a bony fish belonging to the teleost order that is named after a fleshy growth on its head that acts to lure its prey. There are many species of anglerfish and some are known for exhibiting extreme sexual dimorphism where males are much smaller than females. The seadevil anglerfish is a family of anglerfish found in the deep sea. The misshapen body and razorlike state of this fish give it its name. While females are around 20 cm long, males are only about 2.5 cm long. Males of this species fuse with female to reproduce and exist as a parasite thereafter.
1. Deep-sea Hatchetfish
With a deep and laterally extremely compressed body just like a hatchet, the hatchetfish is another lifeform in the fathomless depths of the ocean. It also possesses bioluminescent photophores and can regulate the brightness of their glow according to light filtering from above, an adaptation that allows it to escape becoming the food of other creatures. This adaptation is called counterillumination. Predators of this fish find it difficult to detect its silhouette due to light-based camouflage technique. This creature is found at depths ranging from 50 to 1,500 m.