The oldest living vertebrate animal on the planet (that we know of) is a female Greenland shark that is an impressive 400 years old! Researchers found her swimming around in the Arctic. She takes the cake in longevity with a lifespan that outpaces all of the oldest living animals found; except for Ming the clam who reached the age of 507 before some scientists killed it by accident trying to find out how old it was…can you believe that!
Anyway, The Guardian nicely puts this sharks life timeline into perspective:
“This shark was born during a period of time marked by the reign of King James I, was a young shark when the era of colonialism was reaching a peak of intensity in the 1600’s, and was considered an adolescent shark as King George II became a ruler. Around the time the American Revolution occurred in the 1770’s, this particular shark would have been an adult, and it continued to live throughout both world wars.”
Lead author of the research from the University of Copenhagen, Julius Nielsen, says that up until finding the Greenland shark, the oldest vertebrate animal was the bowhead whales who has been found to live up to a little over 200 years old. Some of the other oldest animals on Earth include:
- Adwaita, the oldest giant tortoise who passed away from liver failure at 255 years old.
- Unnamed Geoduck, the saltwater clams with the oldest specimen found to be 168 years old.
- Jeanne Louise Calment, the French woman who set the official record for oldest human lived to 122 year old.
- Charlie the Curser, a blue-and-yellow macaw that was the oldest ever pottymouthed anti-Nazi parrot who lived to 114 years old.
- Lin Wang, the oldest elephant ever observed who passed away at the old age of 86.
Now back to the Greenland shark…
She is one of the largest carnivores in the world with a reported growth rate of just less than one centimeter a year making her about 5 meters long after a few hundred years of growing. Scientists had actually been trying to figure out how old her species was for a long time without avail. Steven Campana, a shark expert from the University of Iceland said:
“Fish biologists have tried to determine the age and longevity of Greenland sharks for decades, but without success. 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.”
Nielson and his peers, an international team of researchers set out determined to discover the age of a set of 28 different female Greenland sharks that were caught during scientific surveys between 2010 and 2013. They described their research in the academic journal Science. This research is the first genuinely solid evidence of how long the sharks can live. “It definitely tells us that this creature is extraordinary and it should be considered among the absolute oldest animals in the world,” Neilsen said.
Normally, biologists can assess the age of a fish by counting the growth layers of calcium carbonates in their ears, kind of like counting tree rings. The problem is, sharks don’t have those earstones so they had to figure out some other way.
What Nielson’s team did instead was examine the lenses in the sharks eyes, an approach called scrutiny of the lenses in their eyes. According to The Guardian:
“The lens of the eye is made of proteins that build up over time, with the proteins at the very centre of the lens laid down while the shark is developing in its mother’s womb. Work out the date of these proteins, the scientists say, and it is possible to achieve an estimate of the shark’s age. In order to determine when the proteins were laid down, the scientists turned to radiocarbon 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. By applying this technique to the proteins at the centre of each lens, the scientists deduced a broad range of ages for each shark.”
What’s really bizarre and unbelievable about this species (and how it has even survived to this point let alone to its record age) is that an adult female Greenland sharks hits sexual maturity only once she has reached more than four metres in length,. That means that she can begin to produce young (offspring) at around the age of 150 years old.
However, even with this evidence, not everyone is convinced that Greenland sharks can live for multiple centuries. For example, Clive Trueman, associate professor in marine ecology at the University of Southampton said:
“I am convinced by the idea of there being long lifespans for these kinds of sharks, [but] I take the absolute numbers with a pinch of salt.”
Skepticism aside, Nielsen is looking forward to further research, and hopes that this news boosts awareness and conservation efforts of the animal because he would love to unravel other aspects of its physiology. He says, “There are other aspects of their biology which are super-interesting to know more about and to shed light upon.”
It’s too bad the shark can’t talk a language we understand. How interesting would that be to hear what a 400 year old creature has to say!