Scientists Film The Deepest-Swimming Fish Ever Discovered At Five Miles Below The Surface

Published April 3, 2023
Updated April 4, 2023

The young snailfish was spotted at a depth of more than 27,000 feet in the Izu-Ogasawara Trench off the coast of Japan.

Deepest Fish Ever Found

University of Western AustraliaCertain species of snailfish like these have evolved to thrive in the deep ocean.

In the impenetrable darkness of the deep sea, scientists working off the coast of Japan have made an incredible discovery. At a depth almost equal to the height of Mount Everest, researchers have used undersea cameras — and tasty bait — to capture the deepest swimming fish on film.

Scientists from the University of Western Australia and Tokyo University of Marine Science and Technology captured a swimming snailfish at the stunning depth of 8,336 meters (or over 27,000 feet) while recording undersea footage in Japan’s Izu-Ogasawara Trench.

“If this record is broken, it would only be by minute increments, potentially by just a few meters,” Alan Jamieson, founder of the Minderoo-UWA Deep Sea Research Centre who led the expedition, told BBC News.

Deepest Fish

Alan Jamieson/TwitterThe young snailfish was filmed with an autonomous camera at more than 27,000 feet deep.

Indeed, the new record beats the previous one by less than 200 meters. As the BBC reports, the previous deepest fish observation was made at 8,178 meters (or 26,830 feet) in the Pacific Ocean’s Mariana Trench in 2017. The snailfish fish recorded in the Izu-Ogasawara Trench were observed swimming 158 meters (or 518 feet) deeper than that.

As the Independent reports, the research team captured the deep-swimming fish by dropping an autonomous “lander” camera straight into the Izu-Ogasawara Trench. Packed with bait, it quickly drew undersea creatures like the snailfish which swim “very close to” the maximum depth fish can survive, according to the researchers.

The deepest swimming fish ever recorded, certain kinds of snailfish have evolved specifically to thrive in the ocean depths. Though they often stick to shallow water and can be found in places like river estuaries, some snailfish can survive in deeper waters.

According to the BBC, they have gelatinous bodies which help them manage the extreme pressure below the sea. These strange fish also lack swim bladders, which other fish use to control buoyancy, which helps them to swim to great depths. Once there, snailfish — suction feeders — can feast on the small crustaceans that live in deep ocean trenches.

Fish Near Camera

Minderoo-UWA Deep Sea Research CentreDeep sea fish were attracted to the undersea cameras by a selection of tasty bait.

Recording the deepest swimming fish wasn’t the only record that the research team established, however. CNN reports that they also caught two other snailfish — identified as Pseudoliparis belyaevi — at a depth of 8,022 meters (26,318 feet), which set a record for the deepest catch.

This exciting discovery is not the first for Jamieson, who is also credited with discovering the deepest octopus, jellyfish, and squid. But Jamieson is eager to keep exploring the ocean. The only restraint, he explained to CNN, is the cost. Each lander costs $200,000 to assemble and operate.

“The challenges are that technology has been expensive and scientists don’t have a lot of money,” he said.


University of Western AustraliaThe two snailfish caught by the research team at the astounding depth of 8,022 meters (26,318 feet).

Still, Jamieson is optimistic about future studies of the deep sea. He notes that scientists have started to decipher the mysteries of the ocean depths more than people realize.

“We predicted the deepest fish would be there and we predicted it would be a snailfish,” Jamieson told the BBC. “I get frustrated when people tell me we know nothing about the deep sea. We do. Things are changing really fast.”

After reading about the deepest swimming fish ever recorded on camera, look through these photos of fascinating deep sea creatures documented by Australian scientists on the RV Investigator. Or, discover the story of the Challenger Deep, the deepest part of the ocean at 11,000 meters.

Kaleena Fraga
A staff writer for All That's Interesting, Kaleena Fraga has also had her work featured in The Washington Post and Gastro Obscura, and she published a book on the Seattle food scene for the Eat Like A Local series. She graduated from Oberlin College, where she earned a dual degree in American History and French.
John Kuroski
John Kuroski is the editorial director of All That's Interesting. He graduated from New York University with a degree in history, earning a place in the Phi Alpha Theta honor society for history students. An editor at All That's Interesting since 2015, his areas of interest include modern history and true crime.
Cite This Article
Fraga, Kaleena. "Scientists Film The Deepest-Swimming Fish Ever Discovered At Five Miles Below The Surface.", April 3, 2023, Accessed April 20, 2024.