The Greenland shark is an apex predator and spends much of its time in cold deep waters, measuring up to five meters long.
Scientists have found a Greenland shark that's 400 years old! The female shark is the longest-living vertebrates known on Earth and is the king of the food chain in Arctic waters, scientists said. The researchers determined the age of the shark by using carbon dating and was shocked to find the shark was roughly 400 years old, setting a new record for longevity. The previous record for the oldest vertebrate animal was held by the bowhead whales that lived over 200 years. The new finding sees the shark exceed the longest-living human being by more than three times. It was a 122-year-old Frenchwoman Jeanne Louise Calment who holds the record of being the longest-living human being, reported The Guardian. The Greenland sharks are grey, plump, and grow up to five meters, making it one of the world’s largest carnivores. They are often found swimming slowly in the cold deep waters of the North Atlantic.
The 400-year-old Greenland shark was one of 28 that researchers had used carbon dating to find their age. The researchers found the Greenland sharks grew at just 1cm a year and attained sexual maturity at the age of 150 when they are 4 meters long. "It kicks off the bowhead whale as the oldest vertebrate animal," said Julius Nielsen, lead author of the research from the University of Copenhagen. The research was published in the journal Science. Nielsen said the bowhead whales were known to live for 211 years. However, the longest-lived animal continues to be Ming, an Icelandic clam known as an ocean quahog, that lived up to 507 years.
The Greenland sharks are the king of the food chain in the Arctic waters, which made it hard for scientists to determine how old they were. "Fish biologists have tried to determine the age and longevity of Greenland sharks for decades but without success," said Steven Campana, a shark expert from the University of Iceland. "Given that this shark is the apex predator (king of the food chain) in Arctic waters, it is almost unbelievable that we didn’t know whether the shark lives for 20 years, or for 1000 years." The new findings are the first concrete evidence of their age. "It definitely tells us that this creature is extraordinary and it should be considered among the absolute oldest animals in the world," said Nielsen. The data on the Greenland sharks were obtained during scientific surveys held between 2010 and 2013.
It is common for scientists to determine the age of fish by counting the growth layers of calcium carbonate "stones" found in their ears – similar to counting tree rings. However, sharks do not have such ear stones. Additionally, Greenland sharks lack other calcium-rich tissues suitable for this type of analysis. For Greenland sharks, scientists relied on the proteins that build up over time at the center of its eye. The proteins are laid down while the shark is developing in its mother’s womb, so scientists used radiocarbon dating to find the date of these proteins in an effort to estimate the age of the shark. In carbon dating, a method that relies on determining within a material the levels of a type of carbon, known as carbon-14, that undergoes radioactive decay over time.
Nielsen said the female Greenland shark was likely to be 392 years but said the range of the possible ages stretches from 272 to 512 years. "The Greenland shark is now the best candidate for the longest living vertebrate animal," he said. The scientists estimated the shark's birth year to be between 1501 and 1744. "Even with the lowest part of this uncertainty, 272 years, even if that is the maximum age, it should still be considered the longest-living vertebrate," said Nielsen, reported BBC.