The transparent-headed Pacific Barreleye spends much of its time motionless, at more than 2,000 feet (600 meters) beneath the ocean’s surface.
The green lens atop each of the fish’s eyes filters out what little sunlight makes it down from the surface, allowing the fish to focus on the bioluminescence of small jellies or other prey passing overhead.
Then the eyes rotate forward to follow the prey, allowing the fish to home in on its meal.
The 6-inch (15-centimeter) Barreleye (Macropinna microstoma) had been known to science since 1939 – but only from mangled specimens found in fishing nets nets.
Source: National Geographic and YouTube.