Photo: Minderoo-UWA Deep-Sea Research Centre “Rovers and landers gain a deeper understanding of the unexplored regions of our planet's oceans,” she wrote.Snailfish seen more than eight kilometres below the surface of the ocean. In an e-mail to Scientific American, ichthyologist Dahiana Arcila, curator of marine vertebrates at the University of California, San Diego’s Scripps Institution of Oceanography, noted the part played by technology in the discovery. “Once they’ve evolved to cope in a trench, they cannot decompress to get from one trench to another.” “Each trench has its own snailfish in it,” he says. More than 400 species of snailfish are known from shallow waters to extreme depths, and each species adapts to where it lives, Jamieson says. Though the team couldn’t identify the type of snailfish, two others from the species Pseudoliparis belyaevi were caught in baited traps nearby, at a depth of 8,022 meters. The lander that made the finding photographed a single juvenile snailfish at 8,336 meters. The researchers used landers that carried dead fish as bait deep-sea crustaceans ate the bait, and the snailfish came to eat the crustaceans. To photograph the fish, researchers onboard the DSSV Pressure Drop sent down a “lander”-an autonomous underwater vehicle equipped with cameras, lights and batteries, along with a weight to carry the contraption to the seafloor. “But it makes a difference to marine animals.” “The difference is a fraction of a degree, so we wouldn’t care,” Jamieson says. Osmolytes are less effective at low temperatures, and these snailfish are living near the edge of what’s possible. The warmer water seems to be why the snailfish survive. The deepest parts of the Japanese trench are slightly warmer than the Mariana, reaching about 1.7 degrees Celsius (35 degrees Fahrenheit), Jamieson says. The team was using crewed and uncrewed underwater vehicles to explore deep ocean trenches, and the Izu-Ogasawara connects in the south to the deepest, the Mariana Trench. Jamieson’s team discovered the snailfish in August 2022 at the bottom of the Izu-Ogasawara Trench, near the main islands of Japan. “I can barely swim to the bottom of a swimming pool without my ears popping.” “At that depth, everything from gas exchange for breathing to nearly every physiological function seems impossible,” he says. Ichthyologist Prosanta Chakrabarty, curator of fishes at Louisiana State University’s Museum of Natural Science, is impressed that the fish, a species in the genus Pseudoliparis, could survive so far down, where the water pressure is 800 times that of the surface. “If anyone does find fish deeper than this, it will not be by much,” Jamieson says. So that’s the theoretical limit of fish physiology. Osmolyte concentrations increase at greater depths to ensure that fish cells don’t shrink too much at such bone-crushing pressures, but these compounds reach their maximum concentration at around 8,400 meters. The previous record holder, a juvenile snailfish seen in the Mariana Trench, was filmed at a depth of 8,178 meters in 2017.įish withstand the high pressures of extreme depths because of compounds called osmolytes in their cells. “They can’t really go any deeper,” says deep-sea scientist Alan Jamieson of the University of West Australia, who led the team that made the discovery. The tadpole-shaped, translucent creature is a type of snailfish, and it’s probably the deepest fish anyone will ever find. Scientists exploring a marine trench near Japan were astonished to find a fish in one of the deepest parts of the ocean, at 8,336 meters (about five miles) below the surface.
0 Comments
Leave a Reply. |