Flashing fishon display atSouthsea's Blue ReefAquarium

The flashlight fish, as they are known, have special, bean-shaped light organs below their eyes which they can turn on and off at will.

Found in the warm waters of the Pacific Ocean, Indian Ocean and Red Sea, the species has gone on show in a specially-darkened display at the aquarium.

Blue Reef Aquarium’s Martyn Chandler said: ‘They really are an extraordinary fish and, when visitors see their lights flashing in the darkness, they find it hard to believe the light is being produced by a living creature rather than a machine!’

The fluorescent bluish-green glow under a flashlight fish’s eye comes from billions of bioluminescent or glowing bacteria that live under the fish’s skin in a bean-shaped photophore or light organ.

The bacteria biochemically produce this light. This built-in light helps the fish hunt, navigate, communicate and avoid predators and in return, the bacteria get a safe home.