A Four-Century-Old Greenland Shark

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A Four-Century-Old Greenland Shark

A group of researchers from the University of Copenhagen recently conducted a study with the purpose of unveiling the ages of a group of Greenland sharks. The study included 28 Greenland sharks. Surprisingly, they found the age of one of the female Greenland sharks in the sample to be nearly 400 years. According to Julius Nielsen, a marine biologist from the group of researchers, they first hesitated to believe that this Greenland shark was a regular animal. However, lately they have confirmed it. Accordingly, the Greenland shark became the longest-living vertebrate on earth. Previously, a bowhead whale, which is approximately 211 years old, held this record. 

Image credit:- Dive Magazine

Greenland sharks are also called “sleeper sharks” because they swim as slowly as glaciers move. They can be found in the deep levels of the Arctic and Northern Atlantic oceans. The size of the Greenland sharks can be large, up to 5 meters. It is hard to believe that they grow by only 1 centimeter a year. The unbelievable fact is that they stepped into maturity after they became at least about 150 years old. The next curiosity to be fulfilled is why they are gifted such a long lifetime. Their metabolism is the main reason for they are so long-lived. The fact that Greenland sharks consume seals was revealed when scientists could find parts of seals in the stomachs of Greenland sharks. They believe those seals are supposed to be asleep or dead at the time they become the prey of Greenland sharks because Greenland sharks are that slow in swimming.

Image credit:- Dive Magazine

However, it is essential to pay attention to the scientific methodology, researchers used in determining the ages of this group of Greenland sharks. They employed the Radiocarbon Dating technique for this study. They checked the radiocarbon dating of the eye proteins of each Greenland shark. They hypothesized that the sharks with higher radiocarbon levels were less than 50 years old. This assumption is based on information from atmospheric thermonuclear weapon tests launched nearly 400 years ago. The radiocarbon released from those weapons combined with the ocean. That’s why the Greenland sharks born after the tests have a higher level of radiocarbon in their nucleus. Eventually, they estimated the expected age of Greenland sharks to be 272 years, while they can be as old as 512 years at most with 95% confidence.

Image credit:- Dive Magazine

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