New fish species with four eyes 360° vision discovered near New Zealand

The Tasman Sea as seen from New Zealand.
Researchers have discovered a new species of fish with four eyes, giving it 360 degree vision. The silvery ‘Glasshead barreleye’ was discovered by German researchers in the Tasman Sea and can grow to 18cm in length.

The fish inhabits the murky depths between 800 to 1,000m and has two pairs of eyes, allowing it to spot danger from any angle. One pair of cylindrical eyes point upwards, to spot predators from above, but a second set of eyes on the sides of its head contain a mirror-like lens which detect bioluminescence from other deep sea creatures.

The second set of eyes contain silvery layers of guanine crystals, which act as a curved mirror to focus light onto the retina, and are reported to give the fish a wide field of vision. Researchers from the University of Tubingen, who discovered the fish, said that this is unusual as this type of eye is typically associated with invertebrates such as molluscs. They write: ‘This is only the second description of an eye in a vertebrate having both reflective and refractive optics.’

The glasshead barreleye fish (rhynchohyalus natalensis) has four eyes with 360° vision. It is thought that the peculiar creature has evolved with extra eyes (one is circled) so that it can detect prey, predators and mates from every angle

The fish has two primary cylindrical eyes pointing upwards so it can see prey or predators silhouetted against the gloomy light above. It also has a second set of oval-shaped silvery eyes on the side of its head (pictured) which have a mirror-like second lens and retina

The fish studied was caught in the Tasman Sea (illustrated) during an international research project and measures 18cm in length

The deep ocean fish's silvery eyes (marked with arrows) detect bioluminescent flashes of light created by deep-sea creatures to give the glasshead barreleye fish views to its sides and below

Mud skippers (pictured) have eyes on 'turrets' so they can see all around. When they are on mud they can withdraw their eyes into the turrets to clean and lubricate them.