The fish, discovered alive in the deep water off California's central coast by the Monterey Bay Aquarium Research Institute (MBARI), is the first specimen of its kind to be found with its soft transparent dome intact.
The 6-inch (15-centimeter) barreleye (Macropinna microstoma) had been known since 1939--but only from mangled specimens dragged to the surface by nets.
The grayish, barrel-like eyes are beneath the green domes, which may filter light. In this picture the eyes are pointing upward--the better to see prey above in the darkness of the barreleye's deep-sea home.
The transparent-headed fish spends much of its time motionless, eyes upward, MBARI scientists discovered while watching the barreleye fish from a remotely operated vehicle