The ocean is a vast and mysterious place. In fact, experts estimate that we have only explored 5% of the sea’s depths! The deep-sea creatures living in these unexplored waters are some of the most fascinating animals on Earth. They live in an environment completely unlike their land-dwelling relatives, so it should come as no surprise that they look like something out of a sci-fi movie or video game: think giant squids and alien octopi! Here are some of the coolest deep sea creatures you may not know about—and one bonus creature you definitely won’t believe exists.
Viperfish
A viperfish is a fish from the family Chauliodontidae, so-called because of its large fang-like teeth and menacing appearance. These fish live on the ocean floor as deep as 3,000 feet below sea level! Viperfish grow to about 1–2 meters in length. They have a large mouth and round, bulging eyes. Viperfish have an average lifespan of 30 years and can be found in deep ocean waters throughout the world. Viperfish are carnivorous predators. They eat other fish, shrimps, crabs, and mollusks. These fish use their large teeth to catch their prey before swallowing it whole—they can even swallow prey larger than themselves thanks to their elastic stomachs!
Giant Squid
The giant squid is a deep-sea creature that lives in the ocean’s “twilight zone,” about 660 to 3,300 feet below sea level! It is very difficult to observe a few people who have witnessed one alive. Giant squid grows up to 45 feet long and usually live at depths between 1,300 and 3,300 feet. They have a huge heads with eyes the size of soccer balls. The giant squid is one of the world’s largest invertebrates! They are carnivores, feeding on fish, prawns, and other squid. Giant squids have long tentacles with two rows of suction cups lined with sharp-looking hooks that help them capture their prey.
Octopus
An octopus is any species in the order Octopoda—there are around 300 different species! As you likely know, octopuses are cephalopods with eight tentacles. You can tell an octopus apart from a squid because it has suction cups on its tentacles and eight arms (never 10 like a squid!). They also have one big “beak” and three hearts. Octopuses live in the ocean’s deepest trenches at depths of 12,000 feet. They are known for being very intelligent—scientists have even trained some to open jars! These octopuses can grow up to 16 feet in length, depending on their species. Some types of octopuses have a life span of only one year, while others live up to five years.
Giant Isopod
Isopods are crustaceans most commonly referred to as “roly-polies” or pill bugs. Their cousins, the terrestrial woodlice, live on land. Giant isopods, however, are marine bottom-dwellers. They are up to 2 feet long and have a large head, eyes, broad thorax, and broad abdomen with many overlapping segments. Their legs are not well developed so they can’t walk well—they just scoot themselves along the ocean floor using their many limbs. Giant isopods eat dead animals and their own molted exoskeletons. These crustaceans live in deep-sea water at around 3300 feet. They grow slowly: giant isopods reach sexual maturity around age 10 and only live up to 4 years!
Giant Tube Worms
Tube worms live in the ocean and can survive at depths of up to 20,000 feet! They can be found on seamounts and hydrothermal vents—their favorite places to live. These animals have a tubular body with a large mouth and a U-shaped digestive tract. Giant tube worms can grow up to 8 feet long and weigh as much as 44 pounds! They often have many symbiotic bacteria as well as red plumes. Tube worms can live up to 10 years. They eat algae, plankton, and other small crustaceans. Tube worms have a unique defense mechanism: they can actually squirt a tar-like secretion to escape from predators.