If you were asked to name animals that have very long lives, you’re likely, like most of us, to say the tortoise and you wouldn’t be wrong. There are tortoises that lived for about a hundred years. What about whales? Bowhead whales are known to live for around 200 years.
All that may mean little when compared to the Greenland shark.
These sharks that live in the Artic and the North Atlantic may claim to be the longest-living vertebrate animal, according to researchers. Their lifespan may reach 400 years.
If you think about it, 400 years means the shark was alive during the Portuguese occupation of 17th century Malacca. It also means that the shark was probably around when William Shakespeare died and Rembrandt was only ten years-old.
The Greenland shark has a very slow growth rate – about 1 cm every year, according to research that was published recently in the journal Science.
Perhaps because of their slow growth, female sharks are sexually mature when they are about 134 years-old. Now that is a long await for puberty.
Danish marine biologist Julius Nielsen says radiocarbon dating that analysed the shark’s eye lens found that the oldest of 28 sharks they studied was likely about 392 years old (with a 95% certainty of between 272 and 512 years).
“This species is completely overlooked, and only a few scientists in the world are working with this species,” Nielsen says.
“Our findings show that even though the uncertainty is great that they should be considered the oldest vertebrate animal in the world,” Nielsen added.
Greenland sharks have a plump and long body that can grow to about 5.5m or 18ft. It also has a round nose, relatively small dorsal fin, sandpaper-like skin and grey or blackish-brown colouration.
They are slow swimmers and are nearly blind, but are capable hunters, eating fish, marine mammals and carrion. They may also live in the deep sea where the water temperatures are below 5°C.
The population of Greenland sharks is high and they are often seen by deep-sea robots in depths of 2.2km.
– Source: Reuters