The Epipelagic zone is known as the surface layer or the sunlight zone of the ocean ranging from the surface to 656 feet. There is plenty of light and heat within this layer although both decrease as the depth increases. Pressure is also minimal and increases with depth. Most oceanic life and human activities like leisure, fishing, and sea transport occur in the Epipelagic zone. The coral reefs can be found in the layer and the photosynthesis process occurs here.X
Their long, thin tendrils can extend 165 feet in length below the surface, although 30 feet is more the average. They are covered in venom-filled nematocysts used to paralyze and kill fish and other small creatures.X
Bluefin tuna are made for speed: built like torpedoes, have retractable fins and their eyes are set flush to their body.
Above the Bathypelagic zone lies the Mesopelagic layer (Twilight or midwater zone). The Mesopelagic zone lies between 657 feet and 3,281 feet. The zone is home to some of the strangest sea animals like the swordfish and the wolf eel. Faint sun rays penetrate the layer.X
Contrary to popular belief, the "sword" is not used to spear, but instead may be used to slash at its prey to injure the prey animal, to make for an easier catch. The swordfish mainly relies on its great speed and agility in the water to catch its prey.X
The wolf eel is not a true eel, but part of the Anarhichadidae family of “wolf fishes”. They like to live in rocky areas and are able to squeeze into small crevices due to thier long, slender bodies.
The Bathypelagic layer is found between 3,282 feet and 12,124 feet just above the Abyss. This layer is also called the midnight or the dark zone. Although the Bathypelagic zone is dark, visible light may be observed from sea creatures found here. The pressure in the zone reaches 5,858 lbs for every square inch, and a huge number of different sea species are found in the layer. Many animals in this layer are either black or red thanks to low sunlight penetration. Some whale species, like the sperm whale, spend some time at this level in search of food.X
No whale species live permanently in the bathyal zone, but sperm whales, with the large proportion of tissue in their heads protecting them from the immense pressures at depth, are capable of diving into the bathyal zone to hunt.X
These squid are covered in light-producing organs that they use to disorient potential predators. They can turn these lights on and off, making them almost invisible in the dark waters of the deep.
The Abyssopelagic zone, also known as the Abyss or Abyssal zone, lies just above the hadalpelagic layer between 12,125 feet and 19,686 feet. The layer’s name has origins in the Greek language and loosely translates to “no bottom.” Just like the layer below it, temperatures are near freezing point, and there is no penetration of natural light. Pressure is also high due to the weight of the water above. Invertebrates like sea stars and squids can survive in this environment. Over 75% of the ocean floor lies can be found within this zone with the continental rise starting here.X
While they may look squishy, they can crush steel cable with their mouths. They have the largest eyes of any creature on Earth, spanning as big as 18 inches across. They have 10 tentacles. Out of these five, two are for lifting food into the mouth, and the rest are used as a form of propulsion.X
Anglerfish Lure. Their most distinctive feature, worn only by females, is a piece of dorsal spine that protrudes above their mouths like a fishing pole—hence their name.
The Hadalpelagic zone is also called the Trenches and is found from the ocean basin and below. The Hadalpelagic zone lies between 19,687 feet to 36,100 feet. The depth depends on the trenches and valleys in the area. Japan’s Marina Trench is the deepest part of the ocean ever to be explored by man, and it sits at 35,797 feet. In Puerto Rico, fish were discovered at 27,460 feet deep. The zone cannot be explored without specialized kits due to its cold temperatures and high pressure. Natural light cannot penetrate to the Trenches. Different creatures can be found in this layer, mostly invertebrates including starfish.X
These sharks are considered to be living fossils, meaning they’ve roamed deep ocean trenches like the Mariana for millions of years unchanged from an evolutionary standpoint.X
This cuddly looking critter is actually the world’s deepest-dwelling octopus, named for the floppy ear-like fins that protrude from the top of their mantle.