The animal with the longest lifespan is the ocean quahog, a type of clam (Arctica islandica), which can live for over 500 years. Found in the North Atlantic Ocean, these clams have been documented to reach ages beyond 400 years, with some individuals exemplifying remarkable longevity. Their slow growth rate and long life can be attributed to a number of environmental factors, including cold ocean temperatures and the absence of predators. Studying ocean quahogs provides valuable insights into aging processes and climate change, as these creatures can act as indicators of environmental conditions over centuries.