What animal has the longest lifespan?
The animal that has the longest lifespan is the Turritopsis dohrnii, also known as the "immortal jellyfish". This species of jellyfish is capable of reverting back to its juvenile state after reaching maturity, thus allowing it to potentially live forever. While it is not clear exactly how long these jellyfish can live, they have been observed to go through this process multiple times and can theoretically live indefinitely under the right conditions. However, it should be noted that many factors can affect the lifespan of an individual jellyfish, and their lifespan in the wild is likely to be much shorter than their maximum potential lifespan.