Snailfish, a remarkable group of creatures boasting over 300 species, were at the heart of this groundbreaking discovery. While most snailfish inhabit shallow-water environments like river estuaries, some have evolved to thrive in the icy waters of the Arctic and Antarctic, as well as the extreme pressure conditions of Earth’s deepest ocean trenches.
Their gelatinous bodies equip them to endure the crushing depths of 8 kilometers, where they withstand pressures exceeding 80 megapascals—800 times greater than at the ocean’s surface. Unlike many other fish, snailfish lack a swim bladder, a gas-filled organ responsible for buoyancy control. This absence, surprisingly, aids their survival at these depths.
Furthermore, snailfish are adept suction feeders, preying on small crustaceans that abound in the trench ecosystems, providing them with a plentiful source of sustenance.
The remarkable discovery was made possible through the deployment of cameras on landers, strategically equipped with bait to attract fish into their field of view. Collaborating closely with a team from the Tokyo University of Marine Science and Technology, Professor Jamieson, founder of the Minderoo-UWA Deep Sea Research Centre, led this historic mission.
Professor Jamieson explained that the presence of fish inhabiting depths deeper than those found in the Mariana Trench is likely due to the relatively warmer waters of the Izu-Ogasawara trench. He further noted that the team had anticipated discovering the deepest-dwelling fish in this region and anticipated it would belong to the snailfish family.
Emphasizing the rapid expansion of our understanding of the deep sea, Jamieson countered the notion that we know little about this enigmatic realm. “I get frustrated when people tell me we know nothing about the deep sea. We do. Things are changing really fast,” he affirmed.
This groundbreaking discovery not only unveils the mysteries of the ocean’s darkest depths but also underscores the resilience and adaptability of life in Earth’s most extreme environments, pushing the boundaries of our knowledge about the remarkable creatures that call the deep sea home.