Family CETORHINIDAE


Common name: Basking Sharks

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Summary:

The Basking Shark is the second largest living fish in the world next to the mighty Whale Shark. Despite its huge size and enormous mouth, basking sharks are harmless filter feeders with have thousands of bristle-like gill rakers to strain plankton from the water column. It has a stout streamlined body, 5 huge gill slits that almost encircle the head, a pointed snout with a huge mouth, tiny eyes low on the head, large first dorsal, pectoral and pelvic fins, small second dorsal and anal fin, a lunate caudal fin. Dark greyish-brown above, somewhat paler below.


Cite this page as:
Dianne J. Bray, Basking Sharks, CETORHINIDAE in Fishes of Australia, accessed 17 Oct 2019, http://fishesofaustralia.net.au/Home/family/4

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Family Taxonomy

The family Cetorhinidae contains a single species, Cetorhinus maximus, the Basking Shark.

Family Distribution

Worldwide in cool temperate coastal seas and oceanic waters in coastal areas and in the open ocean; occasionally venturing into subtropical waters. Basking sharks are rare in Australian waters, and are known from about Port Stephens (New South Wales) to Busselton (Western Australia) and around Tasmania in depths from the surface to 500 metres.

Although this pelagic shark is often seen at the surface, a tagged individual was recorded diving to more than 1200 metres (Gore et al. 2008). Basking sharks may spend much of their time at mesopelagic depths. Basking sharks follow summer plankton blooms and are seasonally abudant in some parts of the world.

Family Description

Basking sharks have a stout streamlined body, 5 extremely long gill slits that extend from the top to the underside of the head, a pointed snout with a huge mouth that extends well beyond the small eyes that are low on the head; jaws with rows of minute curved teeth; first dorsal, pectoral and pelvic fins large, second dorsal and anal fins small, caudal fin crescent-shaped.

Family Size

Although basking sharks can grow to more than 12 metres in length and a weight of about 7 tonnes, most individuals are smaller.

Family Colour

Dark greyish-brown above, somewhat paler below.

Family Feeding

Basking sharks are filter feeders, and use thousands of bristle-like gill rakers to strain huge quantities of plankton from the water column. In some parts of the world, basking sharks migrate over long distances, gathering to feed in areas of high zooplankton productivity, such as regions where different water bodies mix (thermal fronts). Gore et al. (2008) reported on tagged sharks that undertook a transatlantic migration from the Isle of Man to Newfoundland. Basking sharks are known to feed on copepods, euphasids, fish eggs, chaetognaths and crustacean larvae.

Family Reproduction

Basking sharks are ovoviviparous probably with intrauterine oophagy. Litters of up to 6 pups are born at about 1.5 metres in length after a long gestation period of more than one year. Male basking sharks mature at 4-5 metres in length, and females at 8-10 metres.

Family Commercial

Basking sharks were historically hunted for their liver oil, that was used industrially and in street lamps, as well as for its flesh. Now, the large fins are in high demand for sale in the Asian shark fin trade. They are also taken as by-catch in a number of fisheries around the world.

Family Conservation

IUCN: The Basking Shark has been globally assessed as VULNERABLE on the 2011 IUCN Red List of Threatened Species (Fowler, 2005). The Northeast Atlantic subpopulation has been assessed as ENDANGERED (Foster, 2009).

CITES: Listed in Appendix II of the Convention on International Trade in Endangered Species (CITES).

Author

Dianne J. Bray

References


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