How long can corals live?

Studies show that some corals can live for up to 5,000 years, making them the longest living animals on Earth.

Longest living. It is not the jellyfish?

Some jellyfish can live for 1-3 years. The jellyfish Turritopsis nutricula is biologically immortal and could, under ideal conditions, live for 1000s of years. After sexually reproducing, this jellyfish can revert back to the immature polyp stage. The jellyfish can still die due to predation, but aging is not a problem for it.