The oldest sea turtle is 400 years old, according to legend. It weights 300 kilogrammes and is kept in captivity in China’s Guangzhou Aquarium. The age of the oldest sea turtle in the wild, however, cannot be determined.
Most sea turtles, particularly males, spend practically all of their lives in the ocean, making it difficult to keep track of their numbers and ages. The leatherback turtle is the largest and oldest known marine turtle species, estimated to have survived for more than 150 million years. Leatherback turtles have a much longer lifespan than other turtles, living up to 100 years.