A young snail fish hovering just above the seafloor at a depth of 8,336 meters was videotaped by a probe sent by scientists to the cliff in the northern Pacific Ocean. Thus, this fish went down in history as the deepest-dwelling fish ever seen.
Scientists at the University of Western Australia and Tokyo University of Marine Science and Technology released images of snail fish taken by marine robots in deep pits off the coast of Japan last September. In addition to filming the deepest-dwelling snailfish, the scientists physically caught two more specimens at 8,022 meters.
The deepest snail fish ever detected lived at 7,703 meters in 2008, while scientists had never been able to collect fish anywhere below 8,000 meters before.
“The important thing is that we see how deep a particular fish species can go in the ocean,” said marine biologist Alan Jamieson, founder of the Minderoo-UWA Deep Sea Research Center, who led the discovery.
Scientists are shooting in pits off Japan as part of a 10-year study of the deepest fish populations in the world. Jamieson said that snail fish are members of the Liparidae family, and while the majority of snail fish live in shallow water, some survive at the greatest depths ever recorded.
During the two-month survey last year, three “landers”, automatic sea robots equipped with high-resolution cameras, were sunk into three pits (Japan, Izu-Ogasawara and Ryukyu pits) at different depths. The images showed the deepest snail fish in the Izu-Ogasawara trench calmly swimming along with other crustaceans on the seafloor.
Jamieson notes that the fish is a young specimen, and younger deep-sea snail fish often stay as deep as possible to avoid larger predators swimming at shallower depths.
Another recording, taken between 7,500 and 8,200 meters in the same pit, shows a colony of fish and crustaceans attached to an undersea robot, gnawing at bait.
The images of the two captured snail fish (identified as Pseudoliparis belyaevi) also offer a rare glimpse into the unique features that help deep-sea species survive in harsh environments. The professor said the Pacific Ocean is particularly conducive to active activities due to the warm southern current, which encourages sea creatures to go deeper, while the abundant marine life is a good food source for bottom-feeders.
Jamieson says scientists want to learn more about creatures that live at extreme depths, but cost is a big limiting factor. He also adds that each dive tool alone costs $200,000 to assemble and operate.