What animal has the longest life span?

An ocean quahog, Arctica islandica, is presently the animal with the longest-known lifespan for a non-colonial animal. Caught in 2006, the clam was discovered to have lived for 507 years.

The average quahog clam does not ordinarily live for 500-plus years. However, this particular clam, picked up in the Icelandic waters, had its age confirmed by carbon-14 dating. Additionally, it was still alive when caught; it died when the British researchers froze it in their lab, unaware of the rarity of their find. After its amazing age was later established, it was called Ming - in reference to the Chinese Ming Dynasty.