Cookiecutter shark

The luminous shark, also known as the cookiecutter shark, is a small deep-sea fish that glows in the dark. It lives in warm ocean waters around the world, often near islands, and travels up and down the water column daily. Its most striking feature is the ring of light-emitting spots on its belly, except for a dark band around its throat.

• Glows with light-producing organs called photophores covering its underside.
• Swims between deep water and the surface every day, moving up to 3 km.
• Grows no longer than 56 cm, with a cylindrical body and big eyes.