Marine biologists have gotten the first footage ever of a school of fish living 4.8 miles beneath the ocean's surface in the cold, pitch black, and fiercely pressurized habitat of the Pacific's Japan Trench. A video shows the pale white hadal snailfish, officially known as Pseudoliparis amblystomopsis, happily wriggling around on the seabed, despite water pressure that the researchers say is equivalent to 1,600 elephants standing on the roof of a Mini.
The fish belong to a species previously known only from five pickled specimens trawled up by Russian scientists in the 1950s, said [researcher] Monty Priede [National Geographic News].
Priede's team of British and Japanese researchers found the rare snailfish during their exploration of deep, narrow marine trenches in Pacific Ocean, and say it was the deepest ever sighting of live fish. The biologists are investigating the mechanics of how marine life exists at such extreme depths. Says Priede:
"There are three problems: the first is food supply, which is very remote and has to come from 8km (5 miles) above. "There is very high pressure - they have to have all sorts of physiological modifications, mainly at the molecular level. And the third problem is that these deep trenches are in effect small islands in the wide abyss and there is a question of whether these trenches are big enough to support thriving endemic populations" [BBC News].
Priede's team, from the University of Aberdeen's Oceanlab, got the footage by sending a remote-controlled device down to the trench's bottom.
The deep-sea equipment needed to survive the extreme pressure at these depths was designed and built by the Oceanlab team specifically for the mission. The submersible camera platforms, or 'landers', take five hours to reach the depths of the trenches and remain on the seafloor for two days before the signal is given for them to surface [Telegraph].
Image: Natural Environment Research Council and University of Aberdeen