The
basking shark (
Cetorhinus maximus) is the second largest living
fish, after the
whale shark, and one of three
plankton-eating sharks besides the whale shark and
megamouth shark. It is a
cosmopolitan migratory species, found in all the world's temperate oceans. It is a slow-moving
filter feeder; its common name derives from its habit of feeding at the surface, appearing to be in the warmer water there. It has anatomical adaptations for filter feeding, such as a greatly enlarged mouth and highly developed
gill rakers. Its snout is conical and the gill slits extend around the top and bottom of its head. The gill rakers, dark and bristle-like, are used to catch plankton as water filters through the mouth and over the gills. The basking shark is usually greyish-brown, with mottled skin. The caudal (tail) fin has a strong lateral keel and a crescent shape. The teeth of the basking shark are very small and numerous, and often number one hundred per row. The teeth have a single conical cusp, are curved backwards, and are the same on both the upper and lower jaws. Adults typically reach in length.