What is the longest-lived marine animal?

The ocean quahog is the longest-lived marine animal with a precisely authenticated lifespan, reaching at least 507 years.

The ocean quahog, Arctica islandica, is a burrowing bivalve found in the North Atlantic, including waters around Iceland, the British Isles, and eastern North America. It grows slowly and spends much of its life buried in sandy or muddy seabeds, filtering tiny food particles from seawater.

The famous 507-year-old specimen was nicknamed Ming because it was born around 1499, during China’s Ming dynasty. Researchers estimated its age by counting annual growth lines in the shell, much as tree rings are counted. The clam was collected off Iceland in 2006, before scientists realized how old it was.

The wording matters: corals and other colonial organisms may be older, and some individual marine animals have disputed age estimates. Bowhead whales are among the longest-lived mammals, with lifespans exceeding 200 years, but they do not approach the authenticated record of the ocean quahog.