Basking Shark - Maximum mass (tonnes): 19

The Basking Shark (Cetorhinus maximus) is one of three species of plankton-eating sharks, together with the whale shark and megamouth shark, and is the second-largest living shark and fish after the whale shark. The average adult is 7.9 meters (26 feet) long. Its skin is typically mottled and greyish-brown in color. The caudal fin is shaped like a crescent and has a robust lateral keel. Other common names for the species include sailfish, sunfish, bone shark, and elephant shark. Its popular name in Orkney is hoe-mother, which can be abbreviated to homer and means "the mother of the pickled dogfish".

The basking shark is a migratory species that can be found in all temperate oceans of the world. It is a slow-moving filter feeder, and its common name comes from the way it feeds—appearing to be basking in the warmer surface water—at the surface. Its anatomy has been modified to allow for filter feeding, including a significantly larger mouth and highly developed gill rakers. The gill slits circle the top and bottom of its head, and its snout is conical. Plankton is captured by the gill rakers, which are bristly and black and utilized to filter water past the mouth and over the gills. The teeth are many, tiny, and frequently there are 100 teeth in each row.