General Overview
The Cetorhinidae family is represented by a single living species, the basking shark (Cetorhinus maximus). It is the second-largest living fish after the whale shark, reaching lengths of up to 12 meters. Despite its size, the basking shark is a gentle giant, feeding on plankton rather than large prey. It is distributed widely in temperate oceans and is known for its slow, surface-feeding behavior, from which it gets its name.
Appearance
Basking sharks have a massive, fusiform body with a large, conical snout and an enormous mouth that can open up to one meter wide. Their gill slits are exceptionally long, nearly encircling the head, and are equipped with gill rakers for filtering plankton. The dorsal fin is tall and prominent, while the tail is crescent-shaped. Their coloration is typically gray to brownish, sometimes mottled, with a paler underside.
Diet
Unlike most sharks, basking sharks are filter feeders. They consume zooplankton, small crustaceans, and fish larvae by swimming with their mouths open, filtering seawater through their gill rakers. An adult basking shark may filter several thousand liters of water per hour while feeding.
Habitat
Basking sharks inhabit temperate coastal waters, continental shelves, and open oceans. They are often observed near the surface during the summer months, following seasonal plankton blooms. In winter, they may dive to deeper waters, sometimes over 1,000 meters below the surface, where they continue to feed. Their range includes the North Atlantic, North Pacific, and parts of the Southern Hemisphere.
Behavior
Basking sharks are slow-moving and non-aggressive, often seen swimming leisurely at the surface with their dorsal fin protruding above the water. They are generally solitary but may form loose groups, particularly in feeding areas. Migration is seasonal, with individuals moving between coastal and offshore habitats to follow plankton abundance. Reproduction is ovoviviparous, with females giving birth to live young after a long gestation, though much of their reproductive biology remains poorly understood.
