Longest-living fish – Greenland shark

The Greenland shark is the longest-living shark species on planet Earth. Most other sharks have growth bands that appear on their fin spines in the same way that a tree has growth rings. However, a Greenland shark has no hard tissue in their body and does not grow such bands.

The only way to correctly estimate this shark’s age is through carbon dating, which is not an especially accurate measurement. Using this process, scientists managed to date one female at an age of between 252 and 512 years old. The cold waters that they inhabit mean that they likely have very slow metabolisms, which could account for their longevity as well as their slow swim speeds.

Longest-living tortoise

The longest-living tortoise species in the world is the Aldabra giant tortoise. The oldest was a male called Adwaita and was thought to be 255 years old when he died at Alipore Zoological Garden, Kolkata, India in 2006. Adwaita was thought to have hatched in 1750 and had lived a solitary life at the zoo for over 100 years.

It comes from the Aldabra atoll in the Seychelles, home to approximately 100,000 of his kind. This is the largest concentration of tortoises anywhere in the world.

Published in Dawn, Young World, April 13th, 2024