--- title: "Greenland Shark (Somniosus microcephalus) | AnimalTracks.wiki" description: "The longest-lived vertebrate known to science, growing under a centimeter a year, with females not sexually mature until at least 156 years old, give or take 22." image: "https://animaltracks.wiki/images/animals/greenland-shark-1.webp" published: "2026-09-01" updated: "2026-09-23" --- # Greenland Shark (*Somniosus microcephalus*) > **Status**: Checked against 9 sources, listed under Sources below. > **Tagline**: The longest-lived vertebrate known to science, growing under a centimeter a year, with females not sexually mature until at least 156 years old, give or take 22. > **Soundtrack Vibe**: Glacial Ambient & Drone Soundscapes // Kali Malone, "Heavy With Fruit" > **Soundtrack Links**: [Spotify](https://open.spotify.com/track/5lmSY7B8nAcdGvZrhmiWeT) > **Vibe Match**: Organ chords held so long they barely seem to move, for a shark that grows slowly, swims slowly, and has a lifespan of at least 272 years. ## Biological Superpowers & Stats - **Taxonomy**: *Somniosus microcephalus* - **Danger Level**: Medium - **Conservation Status**: Vulnerable ([IUCN Red List](https://doi.org/10.2305/iucn.uk.2020-3.rlts.t60213a124452872.en)) - **Superpower**: It grows less than a centimeter a year, females aren't sexually mature until at least 156 years old, give or take 22, and its lifespan runs to at least 272 years, the longest of any known vertebrate. - **Habitat**: Cold North Atlantic and Arctic Ocean waters from the surface to about 1,200 meters, in water between 1 and 12 degrees Celsius, and known to dive as deep as 2,200 meters - **Diet**: Cod, herring, skates, eels, seals, and small whales, plus carrion such as reindeer and horse carcasses - **Tags**: shark, ocean, carnivore, scavenger, apex-predator, deep-diver ## Natural History & Behavior ## Ancient by Definition The **Greenland shark** (*Somniosus microcephalus*) cruises the deep, cold water of the North Atlantic and Arctic Ocean, and it does almost everything slowly: it grows slowly, swims slowly, and, by one study, lives longer than any other backboned animal known. Its skeleton has no hard, calcified tissue to grow rings on, the way other sharks are aged. In 2016, researchers found a workaround: the center of a shark's eye lens is made of proteins formed before birth that do not degrade with age. By radiocarbon-dating the eye lenses of 28 female Greenland sharks, a team calculated a lifespan of at least 272 years, making it the longest-lived vertebrate known. The largest shark in the study, a five-meter female, worked out to somewhere between 272 and 512 years old, and the same data put sexual maturity in females at no younger than 156 years old, give or take 22. ## Life in Slow Motion Greenland sharks average roughly 2.4 to 4.3 meters long, and the biggest reach about 6.4 meters. Females are the larger sex, and two in one study weighed 1,100 and 1,367 kilograms. A Greenland shark grows less than a centimeter a year, is known to dive as deep as 2,200 meters, and lives in water as cold as 1 degree Celsius. Researchers estimate a litter could hold up to 200 to 324 pups, depending on the mother's size, each about 35 to 45 centimeters long at birth, though that estimate is still waiting to be checked against a pregnant shark. Slow does not mean picky: it eats cod, herring, skates, seals, and small whales, plus eels, flounders, and other small sharks. It is a slow swimmer that likely ambushes its prey, and it eats carrion too: drowned horses and reindeer have turned up in the stomachs of captured sharks. > **A parasite on the eyeball** Many Greenland sharks have a copepod, *Ommatokoita elongata*, attached to the cornea of one eye. It can scar the cornea and could lead to severe vision loss, possibly blindness, but that does not seem to harm the shark, since it does not rely on its vision. ## Toxic Unless You Know What You're Doing Greenland shark flesh, especially fresh, is toxic to both dogs and people. It carries large amounts of trimethylamine oxide, and the poisoning symptoms appear to come from that chemical breaking down in the gut into trimethylamine. In Iceland, the flesh is traditionally cured into a fermented dish called hákarl instead of eaten fresh. The living shark is another matter: no attack on a person has been confirmed, and the International Shark Attack File lists only one reported attack. ## Frequently Asked Questions ### How long can a Greenland shark live, and how do scientists determine its age? Greenland sharks lack the calcified tissue that other sharks are aged by, so there are no growth rings to count. In a 2016 study, scientists radiocarbon-dated the eye lenses of 28 female sharks (the center of the lens is made of proteins formed before birth that do not degrade with age) and calculated a lifespan of at least 272 years, making it the longest-lived vertebrate known. The largest shark in the study, a five-meter female, worked out to somewhere between 272 and 512 years old. *(Source: [Nielsen et al. 2016]())* ### Why is fresh Greenland shark meat toxic to humans and dogs? Its flesh carries large amounts of trimethylamine oxide (TMAO). The poisoning appears to come from TMAO breaking down in the gut into trimethylamine (TMA), and the fresh flesh is toxic to both dogs and people. Icelanders traditionally cure the meat into a fermented dish called hákarl instead of eating it fresh. *(Source: [Anthoni et al. 1991]())* ### Why do so many Greenland sharks have damaged eyes? Many Greenland sharks have a parasitic copepod, Ommatokoita elongata, attached to one eye. Researchers who examined infected eyes found corneal ulcers and scarring, and concluded the parasite could lead to severe vision impairment, possibly including blindness. Yet the infected sharks looked otherwise healthy, and the infection doesn't seem to seriously weaken them. *(Source: [Borucinska, Benz & Whiteley 1998]())* ## Sources 1. [Somniosus microcephalus (Greenland shark). Animal Diversity Web, University of Michigan.]() 2. [How long do Greenland sharks live? National Ocean Service, NOAA.]() 3. [Somniosus microcephalus. Florida Museum of Natural History, Discover Fishes.]() 4. [Nielsen et al. (2016). Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus). Science.]() 5. [Nielsen et al. (2020). Assessing the reproductive biology of the Greenland shark (Somniosus microcephalus). PLOS ONE.]() 6. [Anthoni et al. (1991). Poisonings from flesh of the Greenland shark Somniosus microcephalus may be due to trimethylamine. Toxicon.]() 7. [Borucinska, Benz & Whiteley (1998). Ocular lesions associated with attachment of the parasitic copepod Ommatokoita elongata (Grant) to corneas of Greenland sharks, Somniosus microcephalus (Bloch & Schneider). Journal of Fish Diseases.]() 8. [Osimani et al. (2019). Unveiling hákarl: A study of the microbiota of the traditional Icelandic fermented fish. Food Microbiology.]() 9. [Kulka et al. (2020). Somniosus microcephalus. The IUCN Red List of Threatened Species 2020: e.T60213A124452872.]() *Published September 1, 2026. Last updated September 23, 2026.* ```json { "@context": "https://schema.org", "@graph": [ { "@type": "Article", "@id": "https://animaltracks.wiki/animals/greenland-shark/#article", "isPartOf": { "@id": "https://animaltracks.wiki/#website" }, "headline": "Greenland Shark (Somniosus microcephalus) | AnimalTracks.wiki", "description": "The longest-lived vertebrate known to science, growing under a centimeter a year, with females not sexually mature until at least 156 years old, give or take 22.", "image": [ "https://animaltracks.wiki/images/animals/greenland-shark-1.webp" ], "datePublished": "2026-09-01", "dateModified": "2026-09-23", "author": [ { "@type": "Organization", "name": "AnimalTracks.wiki Editorial Team", "url": "https://animaltracks.wiki" } ], "publisher": { "@type": "Organization", "@id": "https://animaltracks.wiki/#organization", "name": "AnimalTracks.wiki", "url": "https://animaltracks.wiki", "logo": { "@type": "ImageObject", "url": "https://animaltracks.wiki/icon-512.png" } }, "mainEntityOfPage": "https://animaltracks.wiki/animals/greenland-shark/", "citation": [ { "@type": "CreativeWork", "name": "Somniosus microcephalus (Greenland shark)", "url": "https://animaldiversity.org/accounts/Somniosus_microcephalus/", "publisher": { "@type": "Organization", "name": "Animal Diversity Web, University of Michigan" } }, { "@type": "CreativeWork", "name": "How long do Greenland sharks live?", "url": "https://oceanservice.noaa.gov/facts/greenland-shark.html", "publisher": { "@type": "Organization", "name": "National Ocean Service, NOAA" } }, { "@type": "CreativeWork", "name": "Somniosus microcephalus", "url": "https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/greenland-shark/", "publisher": { "@type": "Organization", "name": "Florida Museum of Natural History, Discover Fishes" } }, { "@type": "ScholarlyArticle", "name": "Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)", "url": "https://doi.org/10.1126/science.aaf1703", "author": "Nielsen et al.", "datePublished": "2016", "isPartOf": { "@type": "Periodical", "name": "Science" }, "identifier": "doi:10.1126/science.aaf1703" }, { "@type": "ScholarlyArticle", "name": "Assessing the reproductive biology of the Greenland shark (Somniosus microcephalus)", "url": "https://doi.org/10.1371/journal.pone.0238986", "author": "Nielsen et al.", "datePublished": "2020", "isPartOf": { "@type": "Periodical", "name": "PLOS ONE" }, "identifier": "doi:10.1371/journal.pone.0238986" }, { "@type": "ScholarlyArticle", "name": "Poisonings from flesh of the Greenland shark Somniosus microcephalus may be due to trimethylamine", "url": "https://doi.org/10.1016/0041-0101(91)90193-u", "author": "Anthoni et al.", "datePublished": "1991", "isPartOf": { "@type": "Periodical", "name": "Toxicon" }, "identifier": "doi:10.1016/0041-0101(91)90193-u" }, { "@type": "ScholarlyArticle", "name": "Ocular lesions associated with attachment of the parasitic copepod Ommatokoita elongata (Grant) to corneas of Greenland sharks, Somniosus microcephalus (Bloch & Schneider)", "url": "https://doi.org/10.1046/j.1365-2761.1998.00122.x", "author": "Borucinska, Benz & Whiteley", "datePublished": "1998", "isPartOf": { "@type": "Periodical", "name": "Journal of Fish Diseases" }, "identifier": "doi:10.1046/j.1365-2761.1998.00122.x" }, { "@type": "ScholarlyArticle", "name": "Unveiling hákarl: A study of the microbiota of the traditional Icelandic fermented fish", "url": "https://doi.org/10.1016/j.fm.2019.03.027", "author": "Osimani et al.", "datePublished": "2019", "isPartOf": { "@type": "Periodical", "name": "Food Microbiology" }, "identifier": "doi:10.1016/j.fm.2019.03.027" }, { "@type": "ScholarlyArticle", "name": "Somniosus microcephalus. The IUCN Red List of Threatened Species 2020: e.T60213A124452872", "url": "https://doi.org/10.2305/iucn.uk.2020-3.rlts.t60213a124452872.en", "author": "Kulka et al.", "datePublished": "2020", "isPartOf": { "@type": "Periodical", "name": "The IUCN Red List of Threatened Species" }, "identifier": "doi:10.2305/iucn.uk.2020-3.rlts.t60213a124452872.en" } ], "about": { "@type": "Taxon", "name": "Greenland Shark", "scientificName": "Somniosus microcephalus", "description": "It grows less than a centimeter a year, females aren't sexually mature until at least 156 years old, give or take 22, and its lifespan runs to at least 272 years, the longest of any known vertebrate." } }, { "@type": "FAQPage", "@id": "https://animaltracks.wiki/animals/greenland-shark/#faq", "mainEntity": [ { "@type": "Question", "name": "How long can a Greenland shark live, and how do scientists determine its age?", "acceptedAnswer": { "@type": "Answer", "text": "Greenland sharks lack the calcified tissue that other sharks are aged by, so there are no growth rings to count. In a 2016 study, scientists radiocarbon-dated the eye lenses of 28 female sharks (the center of the lens is made of proteins formed before birth that do not degrade with age) and calculated a lifespan of at least 272 years, making it the longest-lived vertebrate known. The largest shark in the study, a five-meter female, worked out to somewhere between 272 and 512 years old.", "citation": { "@type": "ScholarlyArticle", "name": "Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)", "url": "https://doi.org/10.1126/science.aaf1703", "author": "Nielsen et al.", "datePublished": "2016", "isPartOf": { "@type": "Periodical", "name": "Science" }, "identifier": "doi:10.1126/science.aaf1703" } } }, { "@type": "Question", "name": "Why is fresh Greenland shark meat toxic to humans and dogs?", "acceptedAnswer": { "@type": "Answer", "text": "Its flesh carries large amounts of trimethylamine oxide (TMAO). The poisoning appears to come from TMAO breaking down in the gut into trimethylamine (TMA), and the fresh flesh is toxic to both dogs and people. Icelanders traditionally cure the meat into a fermented dish called hákarl instead of eating it fresh.", "citation": { "@type": "ScholarlyArticle", "name": "Poisonings from flesh of the Greenland shark Somniosus microcephalus may be due to trimethylamine", "url": "https://doi.org/10.1016/0041-0101(91)90193-u", "author": "Anthoni et al.", "datePublished": "1991", "isPartOf": { "@type": "Periodical", "name": "Toxicon" }, "identifier": "doi:10.1016/0041-0101(91)90193-u" } } }, { "@type": "Question", "name": "Why do so many Greenland sharks have damaged eyes?", "acceptedAnswer": { "@type": "Answer", "text": "Many Greenland sharks have a parasitic copepod, Ommatokoita elongata, attached to one eye. Researchers who examined infected eyes found corneal ulcers and scarring, and concluded the parasite could lead to severe vision impairment, possibly including blindness. Yet the infected sharks looked otherwise healthy, and the infection doesn't seem to seriously weaken them.", "citation": { "@type": "ScholarlyArticle", "name": "Ocular lesions associated with attachment of the parasitic copepod Ommatokoita elongata (Grant) to corneas of Greenland sharks, Somniosus microcephalus (Bloch & Schneider)", "url": "https://doi.org/10.1046/j.1365-2761.1998.00122.x", "author": "Borucinska, Benz & Whiteley", "datePublished": "1998", "isPartOf": { "@type": "Periodical", "name": "Journal of Fish Diseases" }, "identifier": "doi:10.1046/j.1365-2761.1998.00122.x" } } } ] }, { "@type": "MusicRecording", "name": "Heavy With Fruit", "byArtist": { "@type": "MusicGroup", "name": "Kali Malone" }, "genre": "Glacial Ambient & Drone Soundscapes", "url": "https://open.spotify.com/track/5lmSY7B8nAcdGvZrhmiWeT" } ] } ```