A Rare Deep-Sea Fish With a Transparent Head Can See Through Its Forehead

And it lives in the ocean twilight zone.

Irmak Bayrakdar
A Rare Deep-Sea Fish With a Transparent Head Can See Through Its Forehead
The barreleye.MBARI/Twitter

Fish come in all shapes and sizes. And while we’ve had our share of weird-looking fish near the surface, there’s a whole different world down below the deep sea. 

New footage captured by the Researchers with the Monterey Bay Aquarium Research Institute (MBARI) shows a super-rare deep-sea creature called the barreleye fish that’s striking with its transparent forehead and googly eyes. 

Spotting the barreleye

Known as barreleye fish or Macropinna microstoma, these fish live thousands of feet beneath the surface and are very rarely seen. That’s why, when the team spotted the translucent-headed fish with bulging green eyes, they were thrilled. 

While not much is known about the elusive fish, researchers think that the barreleye usually waits motionless to catch prey like zooplankton and jellyfish off-guard. Using their large set of eyes, they can spot shadows of their prey above them while the green pigment in their eyes likely helps filter out sunlight reflecting from the ocean surface.

Seen in Monterey Bay, California, the team had previously come across the species only nine times in spite of more than 5,600 dives with remotely operated vehicles (ROV). 

MBARI says that the barreleye fish usually lives around the Bering Sea, Japan, and Baja California. Living in the ocean twilight zone at about 650 to 3,300 feet (200 to 1,000 m) underwater, the barreleye lives at about 2,000 to 2,600 feet (600 to 800 m) beneath the surface, where the water plunges into complete darkness.

Source: MBARI

Speaking to Live Science, Thomas Knowles, a senior aquarist at the Monterey Bay Aquarium said that at the time of the shooting, MBARI’s ROV was at a depth of about 2,132 feet (650 meters) in the Monterey Submarine Canyon, one of the deepest submarine canyons on the Pacific coast. “The barreleye first appeared very small out in the blue distance, but I immediately knew what I was looking at. It couldn’t be mistaken for anything else.” 

After realizing they hit the jackpot, the team was thrilled about being able to get a clear shot on the fish. Since it’s a very rare sighting, Knowles told Live Science that they “… all knew that this was likely a once in a lifetime experience.”