Which animal has the longest lifespan?

Among animals with a definite lifespan, the ocean quahog clam is a record holder, with one individual named Ming determined to be around 507 years old by counting growth rings in its shell. Greenland sharks are also extraordinarily long-lived, with estimates suggesting some may reach 400 years or more, making them the longest-lived vertebrates. Certain species push the limits of biology further, such as the immortal jellyfish, which can revert to an earlier life stage and potentially avoid dying of old age. Large tortoises can live well past 150 years. Cold, stable environments often favour very long lives.