A decade ago, a deep-sea scientist from the University of Western Australia made a remarkable prediction: that fish might be discovered at astonishing depths ranging from 8,200 meters to 8,400 meters beneath the ocean’s surface. After years of extensive research conducted worldwide, that audacious prediction has now become a captivating reality.
A few snailfish were retrieved from a depth of 8,022m – it is the deepest catch ever. Image credit: Minderoo-UWA Deep Sea Research Centre
Snailfish are an impressive group of creatures, with more than 300 species, most of which inhabit shallow-water environments such as river estuaries. However, some snailfish have also evolved to survive in the frigid waters of the Arctic and Antarctic, as well as under the extreme pressure conditions found in the deepest ocean trenches on Earth.
Their gelatinous bodies enable them to live at depths of 8km, where they endure over 80 megapascals of pressure, which is 800 times greater than that at the ocean surface. Also helping them is the fact that, in contrast to many other fish, snailfish lack a swim bladder, which is a gas-filled organ used for buoyancy control.
Moreover, snailfish are suction feeders that consume small crustaceans, a plentiful food source in the trenches.
Cameras on landers are deployed with bait to attract fish into their field of view. Image credit: Minderoo-UWA Deep Sea Research Centre
According to Professor Jamieson – who is the founder of the Minderoo-UWA Deep Sea Research Centre, which collaborated with a team from the Tokyo University of Marine Science and Technology during this mission – the discovery of a fish that inhabits depths greater than those found in the Mariana Trench is likely due to the slightly warmer waters in the Izu-Ogasawara trench. He further explained that the team anticipated discovering the deepest fish in this region and that it would be a type of snailfish.
Jamieson emphasizes that we possess a significant amount of knowledge about the deep sea and that our understanding of it is rapidly expanding.
“I get frustrated when people tell me we know nothing about the deep sea. We do. Things are changing really fast.”
