The natural world showcases an astonishing array of lifespans. Among these, turtles and tortoises are renowned for their remarkable longevity. The popular image of a slow-moving tortoise living for centuries is a reality for many species. This ability prompts questions about which specific turtles live the longest and the biological mechanisms enabling such extended existences.
The Reigning Champion of Longevity
The Aldabra giant tortoise (Aldabrachelys gigantea) is widely recognized for its extraordinary lifespan. These impressive chelonians, native to the Aldabra Atoll in the Seychelles, routinely live for 150 years or more. Jonathan, a Seychelles giant tortoise, is estimated to be 192 years old as of 2025, making him the oldest known living land animal. He was already fully grown when he arrived on Saint Helena in 1882, suggesting he was at least 50 years old. Another notable Aldabra giant tortoise, Adwaita, reportedly lived for 255 years at the Kolkata Zoo.
Biological Secrets to Extreme Lifespans
The exceptional longevity of turtles and tortoises is linked to several biological adaptations. One significant factor is their slow metabolism, burning energy at a reduced rate. This slower metabolic activity can decrease oxidative stress and cellular damage, major contributors to aging. Their ectothermy also contributes to lower energy expenditure, as they do not need to burn calories to maintain a constant body temperature.
Turtles also possess efficient cellular repair mechanisms. They exhibit slower telomere shortening, which helps protect chromosomes from damage during cell division. Some species can rapidly eliminate damaged cells through apoptosis, preventing cellular deterioration. Their robust immune systems help them fight infections and recover from illnesses.
Diverse Examples of Long-Lived Chelonians
While the Aldabra giant tortoise holds the record, many other chelonian species are known for their impressive lifespans. Galapagos tortoises (Chelonoidis niger) commonly live over 100 years in the wild, with some reaching 177 years in captivity. Harriet, a famous Galapagos tortoise, lived to be 175 years old.
Sea turtles also exhibit considerable longevity, with many species living for decades. Green sea turtles (Chelonia mydas) can live 70 to 80 years, while loggerhead sea turtles (Caretta caretta) have a lifespan of 47 to 67 years, and some can reach 80-100 years. Freshwater species like the Blanding’s turtle (Emydoidea blandingii) and the Eastern box turtle (Terrapene carolina) also live for many decades, with confirmed records exceeding 80 and 100 years respectively.
Understanding Their Unique Aging Process
A significant aspect of turtle longevity is negligible senescence, where their risk of mortality does not increase with age after reaching maturity. Unlike many other animals, turtles do not experience a continuous decline in physiological function as they get older. Studies show that 75% of turtle and tortoise species exhibit slow or negligible senescence, with aging rates lower than those in modern humans for 80% of species. Scientists are studying turtles to understand this unique aging process, as it could provide insights into human longevity.
The protective shell also plays a role in their extended lives by offering defense against predators and physical injury. This physical protection reduces mortality rates from external threats, allowing them to live longer and age more slowly. The ability of some species to continue growing throughout their lives may also contribute to their cellular repair and resistance to age-related diseases.