The very deepest depths of the sea are not all that hospitable. They’re so inhospitable, in fact, that much of it is basically empty. The creatures that do manage to survive down there are extraordinarily strange. But scientists have filmed a fish swimming at the deepest depth ever recorded. The footage was captured by an autonomous lander dropped into the Izu-Ogasawara Trench, south of Japan. A type of snailfish in the genus Pseudoliparis was filmed swimming at 27,349 feet deep.
Prior to the most recent sighting, the deepest anyone had ever seen a fish before was in the Mariana Trench, when researchers spotted a fish swimming at 26,831 feet. Since the exact snailfish researchers observed wasn’t captured, it’s not possible to definitively confirm what type it was, but several others were captured a little higher up in the water column at a depth of 26,319 feet. Those were Pseudoliparis belyaevi, and it’s likely that the deeper one was the same kind. The lead scientist on the mission believes that the snailfish was swimming at something very close to the maximum depth any fish could survive.
Snailfish are a pretty amazing species. There are over 300 different types of them, and their habitat varies wildly. From shallow tide pools and river estruaries to the deepest reaches of the sea, they’re able to adapt to life just about anywhere under water. There are a few reasons for this: they have a gelatinous body that is able to be squashed by the immense pressures of the deep sea, and they don’t have a swim bladder, a gas-filled organ most other fish have that controls buoyancy. They feed mostly on tiny crustaceans, many of which live in deep trenches.
Researchers have been looking in the general area where the snailfish was spotted for a long time now, and they assumed they’d eventually find something down there. It’s a common refrain that we don’t know much about the bottom of the sea, but that’s quickly changing.
“We predicted the deepest fish would be there and we predicted it would be a snailfish,” professor Alan Jamieson told BBC News. “I get frustrated when people tell me we know nothing about the deep sea. We do. Things are changing really fast.”
