Its weight has been estimated at 16 t (16 long tons 18 short tons). A 12.27 m (40.3 ft) specimen trapped in a herring net in the Bay of Fundy, Canada, in 1851 has been credited as the largest recorded. Historical sightings suggest basking sharks around 12 m (39 ft) in length, including three basking sharks estimated at ~40 fod (12.5 metres (41 ft)) and a one ~45 fod (14 metres (46 ft)) were reported between 18, but these visual estimates lack good evidence. The average length of an adult is around 7.9 m (26 ft) weighing about 4.65 t (4.58 long tons 5.13 short tons). ![]() The basking shark regularly reaches 7–8.5 m (23–28 ft) in length with some individuals reaching 9–11 m (30–36 ft). It characteristically migrates with the seasons. The shark follows plankton concentrations in the water column, so is often visible at the surface. It is often seen close to land, including in bays with narrow openings. It prefers temperatures of 8 to 14.5 ☌ (46.4 to 58.1 ☏), but has been confirmed to cross the much-warmer waters at the equator. It is found from the surface down to at least 910 m (2,990 ft). It lives around the continental shelf and occasionally enters brackish waters. The basking shark is a coastal- pelagic shark found worldwide in boreal to warm-temperate waters. The association of Pseudocetorhinus from the Late Triassic of Europe with Cetorhinidae is doubtful. Members of the modern genus Cetorhinus appear during the Miocene, with members of the modern species appearing during the Late Miocene. The oldest known members of Cetorhinidae are members of the extinct genus Keasius, from middle Eocene of Antarctica, the Eocene of Oregon and possibly the Eocene of Russia. Following its initial description, more attempts at naming included: Squalus isodus, in 1819 by Italian Zoologist Saverio Macri (1754–1848) Squalus elephas, by Charles Alexandre Lesueur in 1822 Squalus rashleighanus, by Jonathan Couch in 1838 Squalus cetaceus, by Laurens Theodorus Gronovius in 1854 Cetorhinus blainvillei by the Portuguese biologist Felix Antonio de Brito Capello (1828–1879) in 1869 Selachus pennantii, by Charles John Cornish in 1885 Cetorhinus maximus infanuncula, by the Dutch Zoologists Antonius Boudewijn Deinse (1885–1965) and Marcus Jan Adriani (1929–1995) in 1953 and Cetorhinus maximus normani, by Siccardi in 1961. The species name maximus is from Latin and means "greatest". The genus name Cetorhinus comes from the Greek ketos, meaning "marine monster" or "whale", and rhinos, meaning "nose". Johan Ernst Gunnerus first described the species as Cetorhinus maximus, from a specimen found in Norway, naming it. The basking shark is the only extant member of the family Cetorhinidae, part of the mackerel shark order Lamniformes. Overexploitation has reduced its populations to the point where some have disappeared and others need protection. The basking shark has long been a commercially important fish as a source of food, shark fin, animal feed, and shark liver oil. Despite their large size and threatening appearance, basking sharks are not aggressive and are harmless to humans. They may be found in either small shoals or alone. īasking sharks have been shown from satellite tracking to overwinter in both continental shelf (less than 200 m or 660 ft) and deeper waters. This species has the smallest weight-for-weight brain size of any shark, reflecting its relatively passive lifestyle. The teeth have a single conical cusp, are curved backwards and are the same on both the upper and lower jaws. The teeth are numerous and very small, and often number 100 per row. The gill rakers, dark and bristle-like, are used to catch plankton as water filters through the mouth and over the gills. Its snout is conical and the gill slits extend around the top and bottom of its head. It has anatomical adaptations for filter-feeding, such as a greatly enlarged mouth and highly developed gill rakers. A slow-moving filter feeder, its common name derives from its habit of feeding at the surface, appearing to be basking in the warmer water there. The basking shark is a cosmopolitan migratory species, found in all the world's temperate oceans. ![]() In Orkney it is called hoe-mother (contracted homer), meaning "the mother of the picked dog-fish". Other common names include bone shark, elephant shark, sail-fish, and sun-fish. ![]() ![]() The caudal fin has a strong lateral keel and a crescent shape. It is usually greyish-brown, with mottled skin, with the inside of the mouth being white in color. Adults typically reach 7.9 m (26 ft) in length. The basking shark ( Cetorhinus maximus) is the second-largest living shark and fish, after the whale shark, and one of three plankton-eating shark species, along with the whale shark and megamouth shark. Cetorhinus maximus infanuncula Deinse & Adriani, 1953.
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