Caption

Dogfish jaw. Screenshot of a magnetic resonance imaging (MRI) scan of a coronal section through the jaw of a lesser spotted dogfish (Scyliorhinus canicula). The two dark circles at centre left and centre right of the scan are the fish's eyes. The size of the jaw gives information on its age and intake of diet. MRI is used to study internal structures. It uses a strong magnetic field to produce radio emissions from hydrogen atoms in the body. It can image both bone and soft tissues.