In the frigid darkness of the Mariana Trench swims the world’s deepest-living fish — the Mariana snailfish (Pseudoliparis swirei).
The Mariana snailfish (Pseudoliparis swirei). Image credit: Mackenzie Gerringer, University of Washington.
Snailfish are found at many different depths in marine waters around the world. In deep water, they cluster together in groups and feed on tiny crustaceans and shrimp using suction from their mouths to gulp prey.
Little is known about how these fish can live under intense water pressure; the pressure at those depths is similar to an elephant standing on your thumb.
The newly-discovered snailfish species lives at 26,200 feet (8,000 m) below the surface and is endemic to the Mariana Trench, the deepest stretch of ocean in the world that is located in the western Pacific Ocean.
“This is the deepest fish that’s been collected from the ocean floor, and we’re very excited to have an official name,” said Dr. Mackenzie Gerringer, a researcher at the University of Washington.
“They don’t look very robust or strong for living in such an extreme environment, but they are extremely successful.”
During research trips in 2014 and 2017, Dr. Gerringer and colleagues collected 37 specimens of the Mariana snailfish from depths of about 22,600 to 26,200 feet (6,900-8,000 m) along the trench.
DNA analysis and 3D scanning to analyze skeletal and tissue structures helped the team determine they had found a new species.
Since then, marine biologists from the Japan Agency for Marine-Earth Science and Technology have recorded footage of the species swimming at depths of 26,831 feet (8,178 m), the deepest sighting so far.
“Snailfishes have adapted to go deeper than other fish and can live in the deep trenches,” said Dr. Thomas Linley, a researcher at Newcastle University, UK.
“Here they are free of predators, and the funnel shape of the trench means there’s much more food.”
“There are lots of invertebrate prey and the snailfish are the top predator. They are active and look very well-fed.”
Details of the fish’s discovery are published in the journal Zootaxa.
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Mackenzie E. Gerringer et al. 2017. Pseudoliparis swirei sp. nov.: A newly-discovered hadal snailfish (Scorpaeniformes: Liparidae) from the Mariana Trench. Zootaxa 4358 (1); doi: 10.11646/zootaxa.4358.1.7
