# Shark Senescence (DD-701) > The Greenland shark (Somniosus microcephalus) lives in the cold, deep North Atlantic and Arctic. In 2016, Julius Nielsen and colleagues dated proteins in the core of the eye lens of 28 female sharks. Those proteins form before birth and aren't replaced. The team used radiocarbon, including the 'bomb pulse' from 1950s-60s nuclear tests, to estimate ages. The largest shark, 502 cm long, came out at 392 ± 120 years, which puts its likely age between 272 and 512 years. That makes the Greenland shark the longest-lived vertebrate known. The study also estimated that females reach sexual maturity at about 156 ± 22 years. Sharks like this grow only about 1 cm a year in near-freezing water. - Department: Nature (also Science) - First published: 2026-02-22 - Last updated: 2026-02-22 - Permalink: https://detailenjoyer.com/case/shark-senescence/ - Author: Marcus Easterling (DetailEnjoyer), The Detail Department ## On the timeline - **2016**: Nielsen and colleagues use eye-lens radiocarbon to estimate Greenland shark ages Full timeline: https://detailenjoyer.com/timeline/?case=shark-senescence ## Quick facts - **DD-701-F01**: The largest Greenland shark studied was estimated at 392 ± 120 years. _(Write-up · Exhibit C (The numbers))_ - **DD-701-F02**: Females are estimated to mature at about 156 years. _(Write-up · Exhibit D (Late bloomers))_ ## Write-up Born before the US existed. Greenland sharks may live for about 400 years. 1. **A clock in the eye**: The proteins at the center of the eye lens form before birth and stay put for life, so their carbon records when the shark was born. 2. **The bomb pulse**: Atmospheric nuclear tests in the 1950s-60s spiked carbon-14 levels. Sharks whose lens cores carried that signal were younger than about 50 years, which helped calibrate a growth curve for the older ones. 3. **The numbers**: Of 28 females studied, the largest (502 cm) was estimated at 392 ± 120 years, with a 95% probability range of about 272 to 512 years. 4. **Late bloomers**: With growth of roughly 1 cm a year, females are estimated to reach sexual maturity at about 156 ± 22 years. 5. **Cold and slow**: The species lives in near-freezing water down to great depths, and a slow metabolism there is thought to contribute to its long life. ## Related case files - [Resting Rosie (DD-709)](https://detailenjoyer.com/case/resting-rosie/): Another shark case - [Whale Milk (DD-729)](https://detailenjoyer.com/case/whale-milk/): Another case about a large marine animal - [Bathypterois grallator (DD-580)](https://detailenjoyer.com/case/bathypterois-grallator/): Another fish of the deep, cold ocean - [Ursine Uptime (DD-681)](https://detailenjoyer.com/case/ursine-uptime/): Another animal with an extraordinarily slow metabolism ## Reel vs. record - **Precision**: the '272 years' is the low end of the 95% range for the largest shark. The central estimate is 392 ± 120 years (Nielsen et al., 2016). - **Uncertain upper end**: 'more than 500 years' is the top of the uncertainty range (about 512), not a measured age. - **Method detail**: the dated proteins are in the lens nucleus, which forms before birth. The 1950s-60s nuclear-test 'bomb pulse' helped calibrate the ages. - **Missing context**: females are estimated to reach sexual maturity at about 156 ± 22 years. - **Scope**: it's the longest-lived vertebrate known. Some invertebrates, such as the ocean quahog clam, live longer. ## Video: Shark Senescence: Born Before the US Existed - Duration: 22.2 s · Published: 2026-02-22 - File: https://detailenjoyer.com/assets/videos/DVEZEcqEWh7.mp4 ### Transcript DID YOU KNOW? The Greenland shark is one of the most extraordinary long-lived animals on Earth, holding the record for the longest lifespan of any known vertebrate. Scientific studies using radiocarbon dating of proteins in the shark's eye lenses estimate that these slow-growing sharks can live at least 272 years, and possibly more than 500 years, with individual age estimates often centered around roughly 400 years for the largest specimens. NOW YOU KNOW! ## Questions & answers **Q: What part of the shark was radiocarbon-dated?** A: Proteins in the eye lens nucleus. _(Source: Write-up · Exhibit A (A clock in the eye) · Nielsen et al. (2016), Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus), Science; Science news (2016): Greenland shark may live 400 years, smashing longevity record)_ **Q: What was the central age estimate for the largest shark?** A: 392 ± 120 years. _(Source: Write-up · Exhibit C (The numbers) · Nielsen et al. (2016), Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus), Science; Science news (2016): Greenland shark may live 400 years, smashing longevity record)_ **Q: Roughly when do females reach maturity?** A: About 156 ± 22 years. _(Source: Write-up · Exhibit D (Late bloomers) · Nielsen et al. (2016), Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus), Science)_ **Q: What calibrated the young sharks' ages?** A: Carbon-14 from 1950s-60s bomb tests. _(Source: Write-up · Exhibit B (The bomb pulse) · Nielsen et al. (2016), Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus), Science)_ **Q: What is the Greenland shark's scientific name?** A: Somniosus microcephalus. _(Source: Write-up · Exhibit A (A clock in the eye) · Nielsen et al. (2016), Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus), Science; Science news (2016): Greenland shark may live 400 years, smashing longevity record)_ ## Sources - [Nielsen et al. (2016), Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus), Science](https://www.science.org/doi/10.1126/science.aaf1703) - [Science news (2016): Greenland shark may live 400 years, smashing longevity record](https://www.science.org/content/article/greenland-shark-may-live-400-years-smashing-longevity-record) - [Wikipedia: Greenland shark](https://en.wikipedia.org/wiki/Greenland_shark) ## Cite this case file Easterling, Marcus. "Shark Senescence." The Detail Department (DetailEnjoyer), case file DD-701, last updated Feb 22, 2026. https://detailenjoyer.com/case/shark-senescence/