Researchers at the Monterey Bay Aquarium Research Institute (MBARI) have obtained footage of the elusive Pacific barreleye fish (Macropinna microstoma).
This 6-inch long fish has a transperent dome for a head. Its eyes are underneath green lenses which filter out whatever sunlight trickles down 600 metres below the ocean's surface, where it resides. Its eyes can pivot. It is thought to feed on fish it steals from certain jellies known as siphonophores.
The fish has been known since 1939, but no one was able to retrieve an intact specimen until now.
A video that summarizes these points and and contains the footage.
Some of the accompanying photos.
Video and images from National Geographic. Click to read more.