The oldest vertebrate in the world is the Greenland shark (Somniosus microcephalus), a giant shark that is potentially over 500 years old

Most vertebrates have a lifespan that is either shorter or about the same as our own, but the marine vertebrates can seemingly live a whole lot longer than any of their terrestrial counterparts. The oldest known terrestrial vertebrate was Adwaita, an Aldabra giant tortoise (Aldabrachelys gigantea) that lived to be 255 years old, but for the longest living marine animals, 255 years is only the beginning!

A study published in 2016 tried to figure out the age of Greenland sharks (Somniosus microcephalus) by radiocarbon in their eyes. The scientists measured the levels in 28 female sharks, and their results led them to determine that the lifespan of this shark is at least 272 years ago. However, they believe that the oldest shark they measured was 392 ± 120 years old. This put here somewhere between 272 years and 512 years old, so she could actually be over 500 years old.

A Greenland shark. Image is Public Domain.

This lifespan makes these sharks the longest living vertebrate species we know of, and for all we know there could even be older sharks that were not measured in this study.

Anyway, the same research concludes that the sexual maturity of a female Greenland shark is at least 156 ± 22 years, meaning that they would not be able to get offspring before reaching at least 134 years! When it takes well over a hundred years to become fertile, it really do make sense that they can live for half of a millennium.

Maybe we should stop hunting this shark?

The Greenland shark has been used as food for a long time, despite it having toxic levels of trimethylamine oxide in the meat. This toxic is removed by partial fermentation from burying the meat in the boreal ground for 6-8 weeks, and it is considered a delicacy in Iceland.

Now that we know that a single animal must be at least 134 years old before it can get pregnant, my first instinct is to think that we should maybe try to prevent people from hunting this shark. I think that the entire population will fall to a dangerous level very rapidly once it reaches a certain threshold, and since it takes so long to repopulation a declining population, we should protect this species before it even reaches levels where it is threatened. It is currently considered Near Threatened by the IUCN, so it is still considered healthy at this time, but it can easily become threatened if we continue to hunt it.

There are lots of older organisms as well!

Despite the fact that the Greenland shark is the vertebrate with the longest lifespan, there are other non-vertebrate organisms that can live a whole lot longer! For instance, endoliths can be million of years old, some trees can be 5,000 years old, and some species have a biological immortality where they do not age. The immortality might not be like you would have expected immorality to be, but they are still able to live forever under the right conditions.

Thanks for reading!