What animals live for a very long time?

There are several species that scientists do not know for sure if they even have a determined lifespan like great white sharks and certain clams. I saw a show on this where they captured turtles in louisiana or somewhere that had arrow heads and musket embedded in their shells that had healed and grown over them also some times whale hunters will find stone or wooden harpoon points grown over in whales that are hundreds of years old.