Researchers capture footage of rare fish with transparent head

The fish lives in "the twilight zone" of the ocean.

Researchers in California have captured extraordinary footage of a fish with a transparent head. The sighting of the fish was made by aquarist Tommy Knowles and his team on December 9 while on board the research vessel Rachel Carlson while they were collecting jellies and comb jellies for an upcoming exhibition at the Monterey Bay Aquarium Research Institute (MBARI). The creature is known as a barreleye fish, or Macropinna microstoma to give it its Latin name, and lives in the twilight zone, at depths of 2,000 to 2,600 feet (600 to 800 meters). This is the part of the sea that is just beyond the reach of sunlight. It is so rare that in 5,600 dives and more than 27,600 hours of video, MBARI has only encountered the barreleye nine times. Take a look at the remarkable footage below: The fish's light-sensitive eyes rotate within its head and have bright green lenses. Despite their appearance, the two spots above the fish's mouth are not part of the eyes but are in fact similar to nostrils that we have, according to EarthSky. The barreleye's eyes look directly upwards in search of prey, which are usually small crustaceans trapped in the tentacles of other sea creatures. They can then rotate their eyes down so they can eat. They're only a small species though, growing up to 15 cm in size. Clip via MBARI