The deep sea is an extraordinary part of the planet. It accounts for more than 95 percent of Earth's living space. Although it is dark and cold, the deep sea supports an incredible diversity of creatures.While little is known about animals living in deep sea, which means they are at least 650 feet below the ocean surface, where sunlight stops entering, and reaching as low as 7 miles below it, our ability to study and observe them has never been better. The development of remote-operated vehicles, deep-sea cameras and deep-submergence vehicle has made it possible to see the amazing, spiny and fluorescent inhabitants of this mysterious planet.Scientists have made remarkable progress in recent years collecting high-resolution images and videos of deep-sea creatures for everyone to see. They hope to show the world the deep-sea does not seem like a lonely, dark, barren place where nothing can survive, according to Alan Jamieson, a Newcastle University marine biologist. There are amazing animals down there.These are some deep-sea animals that will capture your imagination.MBARI 2011, 2011.Giant larvaceans are about 4 inches long from head to tail. They live in giant mucus orbs that can grow up to 3.3 feet wide. The giant larvacean, like all larvaceans builds its house by secreting a sticky, snotlike substance from the cells that it heads.A giant larvacean will flap its tail to swim and water up to 20 gallons an hour is pumped through its house. This acts as a filter to remove food particles. These houses can become too contaminated with large particles to eat so larvaceans throw them away and build new ones. The seafloor is where the houses that have been discarded sink to, where they are consumed by sea cucumbers and other scavengers. The majority of particles in a mucus home are carbon-rich so when a larvacean throws one away, it is actually sequestering carbon. Their constant house-shedding helps combat climate change because carbon will not return to the atmosphere for many millions of years.They are a common, but unheard of, animal. Tommy Knowles, senior aquarist at Monterey Bay Aquarium, has spent many years working with larvaceans. They are able to connect trophic levels, and provide carbon and nutrients for the deep sea. They are so amazing, so beautiful, but so underappreciated.Schmidt Ocean InstituteResearchers aboard the Schmidt Ocean Institutes vessel Falkor captured this ramshorn squid on video for their first ever time in October 2020. This animal is not technically a squid. It is a cephalopod, despite its name. The rams' horn is a spiraled inner shell that acts as its skeleton. They measure approximately 1 to 3 inches long and have a light-producing orb atop the mantle. This organ allows them to transmit visual signals into the depths.Researchers were carrying out geologic and biologic surveys on Australia's Great Barrier Reef when the researchers saw the animal at nearly 3,000 feet. A coral reef that was taller than the Empire State Building had been discovered by the same researchers the day before.2019 MBARIOne of the most striking deep-sea gems is the bloody-belly jelly. Monterey Bay Aquarium Research Institute researchers discovered this ruby-colored, ruby-colored, ctenophore in 2001. It was named after the creature's blood-red tissue. Although the bright red color of the bloody-belly jelly may make it easy to spot from remote vehicles equipped with cameras and lights, it actually protects it from predators. Red is almost indistinct in deep sea water, which allows the jelly to conceal itself and any bioluminescent organisms being eaten in its stomach.Bloody-belly, like all comb jellyfish, move by beating the iridescent hair-like, cilia that line its bells. The Pacific Ocean has a range of depths that blood-belly comb jellyfish can be found. They are located between 980 and 3320 feet below the surface. The Monterey Bay Aquarium Research Institute filmed this bloody-belly at more than 1,600 feet beneath the Monterey Bay's surface in 2019.Schmidt Ocean InstituteSchmidt Ocean Institute researchers surveyed the depths of the west coast of Australia in April 2020 when they came across the longest known animal on the planet: Apolemia siphonophore, which is 390 feet long. Blue whales measure only 100 feet in length from tail to tip at their largest.Siphonophores, gelatinous colonial organisms, are made up of hundreds of thousands of individuals, also known as zooids. Different types of zooid play different roles in the colony. Some are responsible for propulsion while others have buoyancy and digestion. Although siphonophores are found in all parts of the globe, the record-setting Apolemia was found at approximately 2,000 feet.Schmidt Ocean InstituteThe dumbo octopus, the deepest-dwelling and most adorable genus of octopuses, is one of the most beautiful. They all have skin connecting their tentacles, and ear-like fins which allow them to flap as they fly through the water. They can be found at depths of over 10,000 feet. It is believed that they could live up to a mile deeper. Because they are not prey to many deep-sea predators, dumbos don't have ink sacs. Although Dumbo octopuses are found around the globe, this particular one was discovered off Australia's Great Barrier Reef by scientists aboard the Falkor research vessel. It was located at an estimated depth of 3,000 feet.Schmidt Ocean InstituteFalkor scientists discovered the transparent, scaleless Mariana snailfish while surveying the Mariana Trench in 2014. The new species was named Pseudoliparis swirei in honor of Herbert Swire, a 19th-century biologist who also served as a navigator and helped to discover the trench.Extremophiles can only grow to around 11 inches in length, but they are the most powerful predators in their region. They eat tiny crustaceans found in seafloor sediment.Mariana snailfish have been discovered at depths of more than 26,000 feet. One other fish, the Mariana Trench-dweller closely related, was ever found at depths greater than 26,000 feet. Scientists will likely continue to discover new creatures at extreme depths as they push the boundaries of deep-sea research.Jamieson says that the more we look, we'll find more.Annie Roth (@AnnieRothNews), is a Santa Cruz-based freelance science journalist. She loves writing about endangered species, and the people who study these species.Image of the Dinner Plate Jelly. Credit to Schmidt Ocean InstituteThis article was first published on Oceans Channel's May 2021.