The hadal zone is the deepest region in the ocean, extending from 6,000 meters to 11,000 meters below the surface. This zone does not spread across the ocean floor but exists only in the deepest ocean trenches. Because no light reaches this part of the ocean, it is impossible for plants to thrive but there are still hardy creatures that call these depths home.

Amphipods are soft-shelled crustaceans resembling large fleas. They have been found as deep as 9,100 meters below the ocean surface. Feeding on detritus, amphipods are true bottom feeders. They eat debris from decaying plant and animal matter that floats to the bottom. They are most important as a food source for the larger animals that inhabit the hadal zone.

Primarily lobsters, crabs and prawns, these creatures were spotted at around 7,000 meters by scientists. Found in both the Kermadec and Japan trenches, decapods were spotted actively hunting amphipods. Benthescymus crenatus was the most well represented species at this point in the hadal zone.

Also known as a grenadier, these fish were found at 7,000 meters. Rat-tails have large mouths and a tapering tail which makes them look like giant tadpoles. They also have a well developed sense of smell. They swallow up other fish and crustaceans, moving slowing along the ocean floor to conserve energy as they hunt.

Not much is known about the liparid or snailfish as it had never been seen alive before a 2007 expedition to the Kermadec Trench. It was found at 7,000 meters.

At 11,034 meters down, Challenger Deep is the deepest point in the ocean. Only one life form has been found there. Called protists, these creatures are not actually animals. They are single-celled organisms believed to be related to the first life forms on Earth.