Pseudoliparis belyaevi

Pseudoliparis belyaevi is a snailfish of the family Liparidae that lives in the hadal zone of the northwestern Pacific Ocean, where it has been recorded in the Izu-Ogasawara and Japan trenches. It was described from a single specimen taken between roughly 6,380 and 7,587 meters, and the source notes that a record near 7,579 meters in the Japan Trench may rival the deepest seafloor fish record held by its relative Pseudoliparis swirei. The fish has a slender, tadpole-shaped body with smooth, scaleless, gelatinous skin and reaches about 10.8 centimeters. Like other deep trench snailfishes it depends on low-density tissues rather than a swim bladder, and it is described as feeding by suction on small crustaceans. Little is recorded about its reproduction, lifespan or behavior, and much of what is said is inferred from the wider snailfish family. It is listed as Data Deficient on the IUCN Red List.