Image of a HydraHydra species, freshwater cnidarians, are one of the few groups of animals with no defined aging. The longest studies to date (~8 years) observed no increase in mortality rate, or decrease in reproductive rate and the mortality rate in those hydra was no different than in a clone that was at least 41 years old. Hydra have no sequestered germline which may contribute to this unusual life history.

Ocean Quahog

Ocean Quahog

Image of a Ocean QuahogThe Ocean Quahog (Arctica islandica) is the longest lived unitary animal found yet. Clams and other hard-shelled bivalves have seasonal growth rings in their shells that can be used to estimate their ages. Animals over 100 years old are common and one individual nicknamed Ming (dredged up off Iceland) was estimated to be 507 years old.

You can find more information on quahogs in the Successful Aging library.


Image of YodaYoda was a legendary Jedi Master and stronger than most in his connection with the Force. Small in size but wise and powerful, he trained Jedi for over 800 years, playing integral roles in the Clone Wars, the instruction of Luke Skywalker, and unlocking the path to immortality.

Learn more about Yoda.

Jeanne Calment photographed in 1895


Photo: Jeanne Calment photographed in 1895, age 20.Jeanne Louise Calment, born in 1875, lived until she was over 122 year old. Her lifespan (122 years, 164 days) is the longest reliably confirmed for any human. Mme Calment lived in Arles, France, her entire life. Always athletic, she rode her bicycle until she was 100 and took up fencing in her 80s. All of the ten longest-lived humans with reliable birth records are women.

Photo: Jeanne Calment photographed in 1895, age 20.


Photo: Postojnska Jama SlovenijaThe Olm (Proteus anguinus) is a European cave-dwelling salamander. The olm is estimated to live more than 102 years in the wild. At 10C, its normal environmental temperature, an olm larva takes 16 years to mature into adulthood and lays eggs only once every dozen years. On average adults weigh 17g, less than a tablespoon of sugar, and are about 20 cm (8 inches) in length. Learn more about this remarkable animal in the Successful Aging library.

Photo: Postojnska Jama Slovenija

Bowhead Whale

Bowhead Whale

Image of a Bowhead WhaleBowhead whales (Balaena mysticetus) weigh on average 100,000 kg, about the size of Boeing 757. That’s roughly 17,000 times larger than the rougheyed rockfish and 250,000 times larger than the red sea urchin (seen below). Longevity has been estimated at over 200 years by measuring changes in the eye lens crystallins in harvested animals. Their exceptional longevity was confirmed by the recovery from recent carcasses of bone harpoon tips used only by ancient indigenous hunters in the 19th century and earlier. For more information on bowhead, whale aging explore the Successful Aging library.

Photo: Brian Skerry

Red Sea Urchin

Image of a Red Sea UrchinRed sea urchins (Mesocentrotus franciscanus) show no age-related decline in reproduction or age-dependent changes in mortality rate, suggesting they might not age. Using 14C dating, Ebert and Southon (2003) estimated that urchins they sampled in the wild were as much as 200 years old. A large urchin weighs about 300g — about the same as a box of pasta.

Read more about urchin aging in the Successful Aging library.

Photo: Mehgan Murphy/Smithsonian National Zoological Park

Rougheyed Rockfish

Image of a Rougheyed RockfishThe rougheyed rock fish (Sebastes aleutianus) is found in the north Pacific at depths ranging from 150 to 450 meters. Maximum recorded weight is 6.7 kg, the size of a large housecat. With no apparent decline in egg production at 80 years of age, this animal doesn’t appear to age. The oldest specimen collected off the coast of SE Alaska was aged at 205 years, using seasonal growth rings deposited on otoliths — calcareous bones of the inner ear. Other species in the same Sebastes genus only live into their teens, making this group of fishes particularly interesting for uncovering mechanisms of exceptionally slow aging.

To read more about this and other rockfish explore the Successful Aging library.

Greenland Shark

Image of a Greenland SharkThe large (4 m in length at sexual maturity) Greenland shark (Somniosus microcephalus) has been estimated by radiocarbon dating of eye lenses to live an average adult longevity of 272 years with a maximum estimated at 392 (± 120) years. Age at maturity for females was estimated at 156 (± 22) years. Greenland sharks live in cold water and have a very low rate of growth and metabolism. Their maximum swimming speed was measured at 0.74 meters per second, which is slower than the normal human walking speed.

Brandt's Bat

Brandt's Bat

Image of a Brandt's BatBats comprise 20% of all mammal species and most are remarkably long-lived — on average about three times as long as predicted for their size. Bats, like birds, couple high metabolic rates with exceptional longevity in the wild.

Brandt’s bat (Myotis brandtii) is the longest-lived bat species documented so far. It weighs 7 grams — a bit less than three pennies — based on mark-recapture studies it has a lifespan of at least 41 years in the wild, which is roughly 10 times as long as expected for a typical mammal of its size. You can read more about bat lifespan in the Successful Aging library.

Photo: Jacopo Werther

Naked Mole-Rat

Image of a Naked Mole-RatNaked mole-rats (Heterocephalus glaber) are mouse-sized rodents from equatorial Africa. They live in large subterranean colonies with a single reproductive female and several reproductive males. They have exceptional resistance to cancer. The oldest recorded naked mole-rat was trapped as an adult in the wild and lived in captivity for 30 years. Read more about these animals in the Successful Aging library.

Photo: Mehgan Murphy/Smithsonian National Zoological Park