Greenland sharks have officially become the longest-living vertebrates on Earth. Some individuals can live up to 400–500 years, and their maturation takes over a century.
Greenland shark / © Unsplash
Greenland sharks are officially recognized as the most long-lived vertebrates on the planet. Individual specimens of this species can live up to 4 centuries. Greenland sharks reach sexual maturity at 150 years old, and their juvenile period concludes at 170 years.
This is reported by Space Daily.
What We Know About the Unique Greenland Sharks
Scientists analyzed 28 female Greenland sharks of various sizes—from tiny individuals less than a meter long to giants exceeding five meters. These sharks lack traditional annual rings on their bones or vertebrae, so researchers developed an alternative method for determining their age.
A study published in the journal Science revealed a biological time marker in the fish’s visual organs. The nucleus at the center of the shark’s lens forms before its birth and remains unchanged throughout its life. The carbon within these tissues is a chemical imprint of the shark’s birth moment.
Consequently, scientists employed radiocarbon dating, taking into account the surge in carbon-14 levels in the oceans following nuclear weapons testing in the 1950s. This allowed for the estimation of each shark’s approximate age.
The results were sensational, though they carried a significant margin of uncertainty. The largest shark, measuring approximately five meters, was estimated to be 392 years old. However, the study’s authors honestly note a margin of error of about 120 years in either direction. This means the actual age of this individual is at least 272 years, and by the maximum estimates, over 500 years.
Even the minimum estimated lifespan of a Greenland shark makes it an absolute record-holder among vertebrates. Relying on the average estimate, this fish was swimming in the cold waters of the North Atlantic even before telescopes were invented.
A prolonged life signifies slow stages of development. Greenland sharks attain sexual maturity at 150 years, and their immaturity ends at 170 years.
They spend more time reaching adulthood than a human lifespan. The shark grows only one centimeter per year. This life rhythm is linked to their habitat. Sharks inhabit water with temperatures close to freezing, leading to an extremely slow metabolism. The organism performs all processes slowly, thus living longer.
There is also a downside: a shark that must first live 150 years to reproduce may not be able to quickly replenish its species if populations decline. This vulnerability makes Greenland sharks defenseless against humans.
Previously, they were hunted extensively for their liver oil, and today they frequently become accidental catches in fishing nets. The shark population lacks the resources for recovery. Only the icy water and great depths offer them protection.
Sharks: Latest News
We remind you that an international research group led by Sigehara Kinoshita from the University of Tokyo has, for the first time, assembled the most comprehensive genome of the Greenland shark, covering 96.7% of its DNA.
This creature is the absolute record-holder among vertebrates for longevity—it can live up to 400 years in the cold waters of the Arctic and Atlantic, grows only 1 centimeter per year, and reaches sexual maturity as late as 170 years.
These sharks are almost immune to cancer, which is why scientists began searching for protective mechanisms within their giant genome. DNA analysis helped identify two potential keys to the shark’s longevity: the histone protein H1.0 showed a unique substitution of the amino acid lysine with arginine.
Additionally, the shark possesses 59 copies of the FTH1b gene, which regulates iron levels and the process of ferroptosis. This aids the organism in effectively eliminating damaged or cancerous cells. Both findings remain hypothetical.
Comments Sort: New Old Popular Send