Detail of skin of dead Lesser Spotted Dogfish / Smallspotted Catshark {Scyliorhinus canicula} washed up on strand line following storms. Close inspection reveals the dermal denticles that cover the skin of sharks and rays, giving them a rough, abrasive texture. These tooth-like structures afford protection from predators and ectoparasites. They are also speculated to reduce drag whilst swimming. Anglesey, Wales, UK. December.