Fish look with mirrors!

German scientists have discovered a "four-eyed" fish that uses a unique mirror system to move under the dim ocean.

Spookfish are thought to be the only vertebrate species to develop mirrors to look - Photo: PA

According to scientists from Tuebingen University (Germany), the brown snout fish spookfish living at a depth of more than 900 m is the only vertebrate species that develops mirrors instead of lens to see the image.

These mirrors allow them to detect light rays created by predators in the depths more clearly than those with vitreous lenses, thereby promptly avoiding enemies.

The spookfish seems to have four eyes, but actually only two, each eye split into two adjacent parts.

Living in the deep bottom between Somoa and New Zealand, spookfish need half of their eyes upwards to observe the ocean and food above. The other half, looks like a concave on the fish head, downwards.

These 'extra bag' eyes have tiny mirrors, allowing light to be reflected into a focal point on the retina. This helps the fish see what appears below it.

Professor Hans-Joachim Wagner of Tuebingen University discovered this secret after examining the first spookfish to be taken to the mainland. He and his team took pictures with flash lights to determine the look up and down the fish.