Aldabrachelys gigantea hololissa
Giant tortoises are among the longest-lived animals on the planet. Some individual Aldabra giant tortoises are thought to be over 200 years of age, but this is difficult to verify because they tend to outlive their human observers. Adwaita was reputedly one of four brought by British seamen from the Seychelles Islands as gifts to Robert Clive of the British East India Company in the 18th century, and came to Calcutta Zoo in 1875. At his death in March 2006 at the Kolkata (formerly Calcutta) Zoo in India, Adwaita is reputed to have reached the longest ever measured life span of 255 years (birth year 1750). Today, Jonathan, a -year-old, Saint Helena-dwelling Seychelles giant tortoise, is thought to be the oldest living terrestrial animal on Earth since the 2006 death of Harriet; a 176 year old Galapagos giant tortoise who lived at Australia Zoo. Coming in second to Jonathan is Esmeralda, at years old. Esmeralda is an Aldabra giant tortoise that lives in the Galapagos Islands.
Galápagos green turtle
Galápagos green turtles, grouped with all populations of "Chelonia mydas", are listed on the IUCN Red List of threatened species. They were placed on the list in the mid 1980s and have remained under protection since. One of the major problems that have led to their decline is the slow growth rate and long period from juvenile to sexual maturity. Chelonians average a period of 26–40 years to maturity; the Galápagos green turtle averages 33 years. The green sea turtle has been shown to have the slowest growth rate of any species of sea turtle and is generally long-lived if left undisturbed. Overall, populations of "C. mydas" have had a decrease of about 48–67% of nesting females, but the population that nests in the Galápagos has remained quite steady with little to no change. The population of nesting females recorded in the Galápagos from 1976–1982 was roughly 1400 individuals and after further evaluation in 1999–2001, around 1400 nesting females were found.