Scientists have filmed one of the world's deepest ocean trenches and have found a species of fish nearly five miles below the water surface.
The 30cm/12" fish, called Pseudoliparis amblystomopis, is a member of the snailfish family Liparidae and experts claim it is the deepest living fish species ever discovered.
Dr Alan Jamieson of the University of Aberdeen found the species while working on the Oceanlab on the Japanese research vessel Hakuho-Maru.
"We got some amazing footage from 7700 metres," said Jamieson. "More fish that we or anyone in the world would ever have thought possible at these depths.
"It's incredible. These videos vastly exceed all our expections from this research. We thought the deepest fishes would be motionless, solitary, fragile individuals eking out an existance in a food-sparse environment.
"But these fish aren't loners. The images show groups that are sociable and active - possibly even families - feeding on little shrimp, yet living in one of the most extreme environments on earth."
Extreme environmentThe snailfish were found in the depths of the Japan Trench, which lies east of Honshu Island, north east Japan.
The Trench is part of the Pacific Ring of Fire in the floor of the northern Pacific and is connected to the Kuril-Kamchatka Trench at the northern end and to the Izu-Ogasawara Trench at the south. It is believed to be 9000m deep at the deepest point.
At such depths there is no light, so the fish lack pigment as they don't need to camouflage themselves.
The water is also exceptionally cold - nearly freezing - and the water pressure is "8,000 tonnes per square metre, equivalent to that of 1600 elephants standing on the roof of a Mini car."
The trap used to catch the fish.
Pseudoliparis amblystomopisPseudoliparis amblystomopis was first discovered in 1955 when it was caught at a depth of 7210-7230 metres in the north west Pacific.
It's been recorded from both the Kuril-Kamchatka and Japan trenches - always at depths greater than 6000m.
The Russian ichthyologist AP Andriashev originally named the species Careproctus amblystomopis, but it was later moved to the Pseudoliparis genus.
Liparid snailfishes are members of the Order Scorpaeniformes and are found across the Arctic and Antarctic oceans, as well as in the northern Pacific and Atlantic. Some species occur in UK waters.