The deepest oceans have a way of coming up with some of Earth's strangest creatures. But this unusual fish might have them all beat.
Meet Macropinna microstoma, a small fish who appears to be totally normal - until you get to the see-through head.
Yes, see-through. And that's not the strangest part.
See those little things at the end of his face that look like cute, sleepy eyes? Those are his nostrils, or at least organs that help him smell. His real eyes are the brownish tubes inside his head, ending in those bright green half spheres.
While M. microstoma was first documented in 1939, scientists didn't find a complete fish - and discover their fluid-filled bubble heads - until a few years ago, when researchers at the Monterey Bay Aquarium Research Institute (MBARI) were actually able to witness a live fish in action (scroll down for video).
M. microstoma is a species of barreleye - a type of fish named for their tubular, barrel-shaped eyes. The species developed their transparent heads and tissue to help them navigate the murky depths of their ocean home, more than 2,000 feet below the surface.