Once on the bottom, they waited and watched. And they got some big surprises. “We saw the deepest living fish ever recorded,” says Drazen. “Definitely something new. We took one look at the thing and were amazed — big, wide, winglike fins, this eel-like tail and this scalloped face. It was very unique.” They nicknamed it the “ghost fish” for its almost translucent skin. It appears to be a new species of snailfish — living 5 miles below the surface.
http://www.npr.org/blogs/thetwo-way/2014/12/25/372894314/unexpected-life-found-in-the-oceans-deepest-trench