The oldest confirmed human was a 122 year old French woman named Jeanne Calment, but this pales in comparison to the life expectancy of other species that live on this planet. In fact, there are some animals that live to be hundreds or even thousands of years old. Amazingly, there are even two recorded species that might technically have the capability of living forever. Below is our list of the world’s longest living animals.
1) Turritopsis Nutricula Jellyfish
The Turritopsis nutricula is often referred to as the “immortal jellyfish.” Once this species has become sexually mature it is capable of reverting back to the polyp stage and essentially starting its life over. The jellyfish accomplishes this through cell transdifferentiation in which its cells can turn into other types of cells. For example, its muscles can change into eggs or sperm and life regeneration can begin again. Most Turritopsis die when they are eaten by other animals or if they get a disease while in the initial polyp stage. It is unclear how long one of these creatures lives as knowledge of their regenerative capabilities was not discovered until the 1990’s. Additionally, it is hard to monitor them in their natural habitat and the life rejuvenating process is very quick. This makes it nearly impossible to get an accurate estimate of their age.
The hydra is a tiny freshwater polyp that is related to coral, sea anemones and the jellyfish. Similar to the Turritpsis nutricula jellyfish, the hydra has regenerative powers. Every time you cut one of these tiny creatures apart, each piece quickly develops into a new hydra. Hydras do not appear to age at all. Their bodies are tubular in shape and have a mouth on one end that has poisonous tentacles. The hydra uses its tentacles to paralyze insects and crustaceans after which it consumes them. They only grow to be a little less than an inch long; however, they can consume prey that is up to twice their size. These strange creatures move around by utilizing a cup-like foot or pulling themselves along with their tentacles and then “somersaulting.”
3) Antarctic Sponge
4) Ocean Quahog
The Ocean quahog is an edible clam which has been confirmed to live for more than 500 years. Notably, this mollusk is thought to be an example of negligible senescence, which means that it does not show signs of aging. The Ocean quahog has many names, including: the Icelandic cyprine, black quahog, black clam and mahogany quahog. They are found in the Northern Atlantic Ocean in both deep and shallow waters (25 to 1,300 feet) where they are frequently harvested for food through the process of dredging. The age of a quahog can be established by counting growth rings that appear on its shell. As they get older they tend to grow more slowly, hence the growth rings get closer and closer together. This can make it difficult to determine the exact age of a specimen.
5) Lamellibrachia Tube Worm
Lamellibrachia tube worms are colorful, slow growing, deep sea creatures that live next to hydrocarbon vents that exists on the ocean floor. It is common for them to live for more than 170 years, with some estimated to reach over 250 years of age. Some of the oldest ones can grow to be more than 10 feet long. The most widely known area where they exist is in the northern portion of the Gulf of Mexico at a depth of around 500 to 800 meters. These tube worms use a special body extension called a root to collect hydrogen sulfide from the environment in order to survive.
6) Freshwater Pearl Mussel
The freshwater pearl is a type of endangered mussel that is known for making high quality pearls. The search for valuable pearls is the main cause of their near extinction. Valery Ziuganov, a Russian malacologist, recently discovered that this species shows signs of negligible senescence. This means that the freshwater pearl mussel does not show signs of aging. Valery Ziuganov, along with several other scientists, published a detailed report in 2000 that backs up the belief that these freshwater pearl mussels can often live to be between 210 and 250 years old. Today this species is protected in nearly every European country.
The oldest known vertebrates on the planet are tortoises and it is not entirely uncommon for one to live into its late 100’s. The oldest unconfirmed tortoise was an Aldabra giant tortoise at the Alipore Zoo in India named Adwaita which many people believe to be around 250 years old. Other famous ancient tortoises include a Galapagos tortoise named Harriet who lived to be 175, a spur-thighed tortoise named Timothy who died at the age of 165 and a Seychelles giant tortoise named Jonathan who is estimated to be 178 years old.
8) Red Sea Urchin
It was initially thought that red sea urchins only lived for around 15 years. Recent studies, however, revealed that these creatures frequently live to be over 100 years old and some have been found to be over 200 years in age. By measuring isotope carbon-14 levels in the red sea urchin scientists were able to determine their ages and also get a better idea for their growth rates. The largest and oldest red sea urchins have been found off the coast of British Columbia and near Vancouver Island. This species protects itself from predators with its sharp spines that stick out in all directions. Interestingly, they also use these spines as stilts to walk around the ocean floor. Red sea urchins only live in the Pacific Ocean – mainly along the North American coast.
9) Bowhead Whale
Making the list as the oldest known mammal, the bowhead whale has been estimated to reach ages of over 200 years. Originally it was thought that most bowheads only lived 60 or 70 years like most other whales, but recent studies and findings suggest otherwise. For example, one whale that was captured near the Alaskan coast was found to have the tip of a harpoon lodged in its neck fat. Research showed that the harpoon was manufactured and probably used around 1890. Other amino acid racemization tests of bowhead whale eyes have dated them to be 150 to over 200 years old. It is worth noting that some in the scientific community find these tests to be unreliable.
The tuatara is a lizard-like reptile that is found in New Zealand. Tuataras have very slow growth rates as they do not reach full size until around the age of 35. They can live to be over 100 years old and some experts say that a tuatara living to be 200 would not be out of the question. Tuataras are the only known closely-related living descendants of dinosaurs. They are endangered – with only about 60,000 left in the world. These animals remain fertile very late into their lives. Recently, in captivity, a 110 year old tuatara named Henry mated with an 80 year old female tuatara named Mildred and they produced 11 healthy babies. Henry is still in very good health and is expected to live for several more decades.