Scientists have discovered a new species of fish that glides gently through the water on white, translucent wings 5 miles beneath the ocean surface.
It is the deepest living fish ever discovered.
"We were just blown away when we saw it," said Paul Yancey, a biology professor at Whitman College, Washington who studies how animals adapt to life in the deep sea. "Someone on the ship said it looks like a cross between a puppy, an angel and an eel."
The fish was first spotted in November during an international research cruise to the Mariana Trench -- the deepest place on Earth.
The new fish, which has not yet been named, was discovered by accident. In the video above you can see it swimming around a series of tubes that were part of an instrument collecting mud samples from the sea floor.
The camera was supposed to be filming the core collecting, when suddenly this ghostly fish swam into view.
It is about 10 inches in length, and almost entirely transparent. The dense white part you can see is actually its skull, visible through its skin, Yancey said. It's lengthy, mostly see-through tail is probably made of gelatin.
"It's moving very slowly so it's not clear how well it can swim," he said. "But there has to be some muscle in there somewhere."
The Mariana Trench is located in the Western Pacific, just off the coast of Guam. It starts about 3 miles beneath the ocean surface and stretches to an ultimate depth of 6.8 miles.
Humans couldn't survive even at the top rim of the trench. At that depth, the proteins and cells in our membranes would collapse. And at the bottom of the trench, the pressure is so immense it would be like having 100 elephants standing on your head.
One way deep sea animals survive even under the weight of all that water is with a molecule called trimethylamine N-oxide (TMAO) that protects their proteins from being crushed.
"It's the molecule that makes marine animals like fish and shrimp smell 'fishy,' " said Yancey, "and in deep sea animals there is a lot more of it."
Over the course of the cruise, scientists deployed five deep-sea landers to a variety of depths ranging from about 3 miles to about 6.5 miles to get an overview of the life that flourishes throughout the various strata of this gash in our Earth's crust, and also to sample its geology.
"Many studies have rushed to the bottom of the trench, but from an ecological view that is very limiting. It's like trying to understand a mountain eco-system by only looking at its summit," said Jeff Drazen of the University of Hawaii, who was the co-chief scientist on the research cruise in a statement.
The ethereal deep sea fish was just one of the notable discoveries from the 105 hours of video captured by the research team.
In slightly shallower waters 3.8 miles beneath the ocean, the team's landers took the first video images of bright, white, "supergiant" amphipods that look a bit like the roly poly bugs in your garden, but about 100 times as large.
These animals were first discovered off the coast of new Zealand in 2012, but had never before been seen in their natural environment.
Other measurements reavealed that activity rates of the microbes and worms that live in the sediments at the bottom of the trench were similar to the activity you would see at depths of just several hundred meters. This suggests that the trench could be acting like a funnel that concentrates food at great depths.
"You usually think that the further you get from where the light is, the less life you find, but not in the trench," said Drazen. "These places might be little biological hot spots, and that is really cool."
The 30-day cruise ended in early December, and scientists have barely even started to sift through all the biological and geological data collected on the cruise.
"We have tons of animal samples, mud samples, rock samples, and water samples and when we get back from the holidays, all of us are going to start analyzing those," said Drazen. "Hopefully we'll have many more discoveries in the next year or two."