Greenland sharks (Somniosus microcephalus) have remarkable longevity, with some individuals estimated to live over 500 years.
Update: the DNA of Greenland Sharks
In the news, Scientists have decoded the genome of the Greenland shark, the world’s longest-living vertebrate. They have a documented lifespan of up to 400 years. The shark’s massive genome, containing 6.5 billion DNA base pairs, is twice the size of the human genome and the largest among sequenced shark genomes[1][2]. The research revealed a network of 81 genes unique to the Greenland shark that play a role in DNA repair[3]. Surprisingly, over 70% of the shark’s genome consists of repetitive, self-replicating elements called transposable elements, which may have contributed to its longevity by allowing other genes to hijack their replication machinery[1]. Additionally, scientists identified a specific alteration in the tumor suppressor protein p53, which is known to be important for longevity in many organisms[1]. These findings provide valuable insights into the molecular mechanisms behind the Greenland shark’s exceptional lifespan and may have implications for understanding longevity in other species, including humans.
Factors Contributing to Greenland Shark Longevity
Here are the key things we might learn more about which seem to contribute to their extremely long lifespans:
1. Slow Metabolism
– Greenland sharks have an incredibly slow metabolism, a very low basal metabolic rate, which is believed to be a major factor in their longevity[5][6].
– Their metabolic rate remains stable as they age, unlike most other species whose metabolism declines over time[6].
2. Cold Environment
– These sharks live in deep, cold Arctic waters, with temperatures ranging from -1.8°C to 7.5°C[5].
– The cold temperatures slow down all chemical and biological reactions in their bodies, potentially contributing to their long lifespans[5].
3. Slow Growth Rate
– Greenland sharks grow extremely slowly, at a rate of about 1 cm per year[2].
– They don’t reach sexual maturity until around 150 years of age[2].
4. Unique Biological Adaptations
– Research suggests these sharks have developed unique adaptations to mitigate the effects of aging, such as resistance to oxidative stress and DNA damage[6].
5. Low Predation Pressure
– Living in deep, cold waters, Greenland sharks face few natural predators, reducing their mortality rate[5].
6. Genetic Factors
– Scientists are studying the shark’s genome to understand potential genetic factors that contribute to their longevity[6].
Longevity Secrets of the Greenland Shark
Well, that’s really it folks: To live 500 years, start by having a very slow basal metabolic rate, then keep cold, avoid danger, grow very slowly and this is probably the most important step: don’t have sex for the first 150 years of your life.
What Else Do We Know?
Scientists have made significant discoveries regarding Greenland sharks, known for their remarkable longevity, potentially living over 500 years. Here are the key facts:
– Longevity: Greenland sharks (Somniosus microcephalus) are the longest-living vertebrates, with some individuals estimated to be over 500 years old. One shark was carbon-dated to have lived since 1624[3].
– Unintentional Catches: Greenland sharks are often caught unintentionally in fishing nets, leading to significant population declines. Bycatch is a major threat to many marine species, including these ancient sharks.
– Depth: The closer these sharks are to the equator the deeper they are found, over 7,000 feet down, according to NOAA.
– Size and Habitat: These sharks can grow up to 23 feet long and weigh over 1,000 kg (2,200 lbs). They thrive in the frigid waters of the North Atlantic and Arctic Oceans, typically at depths of over 7,000 feet, where temperatures range from -1.8°C to 7.5°C[2][3].
– Metabolism and Aging: Recent research suggests that the sharks’ slow metabolism may play a crucial role in their longevity. Unlike most species, their muscle metabolic activity remains stable as they age, indicating a unique aging process[5]. The cold temperatures may also slow down biological processes, contributing to their long lifespan[5]. Greenland sharks can tolerate extremely cold temperatures, preferring water between -1°C to 10°C. They are the only shark species that can tolerate Arctic conditions year-round[1].
– Diet and Behavior: Greenland sharks are opportunistic feeders, consuming a variety of prey, including fish, polar bears, horses, and even reindeer. Strange items have been found in their stomachs. Greenland sharks are extremely slow swimmers, with an average cruising speed of just 0.76 mph[1].
– Research Significance: Understanding the adaptations of Greenland sharks could provide insights into human health and longevity, particularly regarding cardiovascular health. Researchers are studying their metabolic processes and genetic material to uncover potential applications for human aging and health[5].
More Facts About Greenland Sharks
- They are rarely observed and somewhat mysterious. The first underwater photos of a live Greenland shark were taken in the Arctic in 1995, and the first video images were not obtained until 2003[1].
- Their teeth are designed to cut out plugs of flesh. The upper jaw anchors food while the lower jaw does the cutting[1].
- Many Greenland sharks are partially blind due to a parasitic copepod that attaches to their eyes. However, they rely more on other senses to hunt in the deep, dark waters they inhabit[1][3].
- Some people eat them. Their meat is toxic if not properly prepared, but is considered a delicacy in Iceland after going through a fermentation process[1][3].
- Their conservation status is listed as ‘Vulnerable’ due to threats from accidental fishing bycatch and climate change affecting Arctic sea ice[3].
These findings highlight the Greenland shark’s unique biological characteristics and their potential implications for science and medicine.
Read More about DNA of Greenland Sharks
[1] https://www.iflscience.com/how-does-this-shark-live-400-years-longevity-secrets-spilled-after-huge-genome-mapped-76066
[2] https://www.leibniz-fli.de/news-events/details/international-team-of-scientists-decodes-the-genome-of-the-greenland-shark
[3] https://www.rapamycin.news/t/this-shark-lives-400-years-its-dna-may-explain-why-ny-times/16408
[4] https://www.nytimes.com/2024/09/22/science/greenland-sharks-genetics.html
[5] https://polarresearch.net/index.php/polar/article/view/3050
[6] https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=191813
[7] https://www.biorxiv.org/content/10.1101/2024.09.09.611499v1.full
[8] https://twitter.com/jpsenescence/status/1837917387380645982
Read More
[1] https://www.triplem.com.au/story/scientists-catch-absolutely-enormous-512-year-old-shark-74102
[2] https://www.npr.org/2022/07/31/1114807928/greenland-shark-longest-living-animal-caught-in-belize
[3] https://en.wikipedia.org/wiki/Greenland_shark
[4] https://www.reddit.com/r/TheDepthsBelow/comments/z78vgz/a_392_year_old_greenland_shark_in_the_arctic/
[5] https://www.earth.com/news/greenland-sharks-live-up-to-500-years-whats-their-secret/
[6] https://www.livescience.com/animals/sharks/secret-of-why-greenland-sharks-live-so-incredibly-long-finally-revealed
[7] https://www.avcr.cz/en/news-archive/The-Greenland-shark-has-the-recipe-for-longevity-living-to-be-over-400-yrs-old/
