What is the common name of the deepest known fish species?

The common name of the deepest known fish species is the Mariana snailfish. Its scientific name is Pseudoliparis swirei, a pale, tadpole-shaped member of the snailfish family Liparidae found in the Mariana Trench.

This fish lives in the hadal zone, the ocean region deeper than 6,000 meters. Recorded specimens have come from roughly 6,198 to 8,076 meters below the surface, including a 7,966-meter capture that set a remarkable depth record for a collected fish. Its body is soft and flexible, helping it withstand pressure that would crush most fish.

The phrase “deepest fish” can cause confusion because an unidentified snailfish has been filmed at greater depths, including 8,336 meters in the Izu-Ogasawara Trench. However, Pseudoliparis swirei remains the deepest-living fish species formally described from the Mariana Trench. It feeds mainly on small crustaceans and other organic matter in one of Earth’s most extreme habitats.