The Greenland shark (Somniosus microcephalus), also known as the gurry shark or grey shark, is a large shark of the family Somniosidae ("sleeper sharks"), closely related to the Pacific and southern sleeper sharks.[2] Inhabiting the North Atlantic and Arctic Oceans, they are notable for their exceptional longevity, although they are poorly studied due to the depth and remoteness of their natural habitat.[3]
Greenland sharks have the longest lifespan of any known vertebrate, estimated to be between 250 and 500 years.[4] They are among the largest extant species of shark, reaching a maximum confirmed length of 6.4 m (21 ft) long and weighing over 1,000 kg (2,200 lb). They reach sexual maturity at about 150 years of age, and their pups are born alive after an estimated gestation period of 8 to 18 years.
The shark is a generalist feeder, consuming a variety of available foods, including carrion.[5]
Greenland shark meat is toxic to mammals due to its high levels of trimethylamine N-oxide,[6] although a treated form of it is eaten in Iceland as a delicacy known as kæstur hákarl.[7] Because they live deep in remote parts of the northern oceans, Greenland sharks are not considered a threat to humans, and no recorded attacks have ever occurred.
^Yano, Kazunari; Stevens, John D.; Compagno, Leonard J.V. (2004). "A review of the systematics of the sleeper shark genus Somniosus with redescriptions of Somniosus (Somniosus) antarcticus and Somniosus (Rhinoscymnus) longus (Squaliformes: Somniosidae)". Ichthyological Research. 51 (4): 360–373. Bibcode:2004IchtR..51..360Y. doi:10.1007/s10228-004-0244-4. S2CID38054192.
^Anthoni, Uffe; Christophersen, Carsten; Gram, Lone; Nielsen, Niels H.; Nielsen, Per (1991). "Poisonings from flesh of the Greenland shark Somniosus microcephalus may be due to trimethylamine". Toxicon. 29 (10): 1205–1212. Bibcode:1991Txcn...29.1205A. doi:10.1016/0041-0101(91)90193-U. PMID1801314.
^Durst, Sidra (2012). "Hákarl". In Deutsch, Jonathan; Murakhver, Natalya (eds.). They Eat That? A cultural encyclopedia of weird and exotic food from around the world. Bloomsbury Publishing USA. pp. 91–92. ISBN978-0-313-38059-4.