Unbelievable and yet true! A species of fish was found with a transparent head and lens-like eyes. It is known by the name “barreleye” (from the English words “barrel” and “eye”).
This fish has huge eyes on the top of its head, which contain a pigment that appears green (although it is actually yellow) and acts as “sunglasses”, allowing it to clearly distinguish other sea creatures that try to to “camouflage”.
In this way, the barreleye can catch its prey at any time, as even animals with bright bellies that work for camouflage cannot escape, since this substance allows it to distinguish between sunlight and bioluminescence .
“It always struck me that their eyes were aimed upwards, but the field of view did not include their mouths. Imagine trying to eat scraps of food floating in front of you while staring at the ceiling,” Bruce Robison, a deep-sea biologist at the Monterey Bay Aquarium Research Institute in California, told the Guardian.
However, after years of study, Robison and his colleagues were finally able to see a barreleye in real time, through the high-definition cameras of a remote-controlled system.
As he explained, his questions were resolved very quickly: “Suddenly it lit up and there I saw that they can rotate their eyes. He also had a transparent canopy over his eyes, like the ones on fighter jets.”
As he speculates, this canopy is probably used as some sort of shield, so that the fish in question protect their eyes from stings as they feed.