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The animal kingdom has incredibly long lifespans that far exceed the average for humans. While humans may have an “hard limit” of 150 years, this is only a nod to the centuries and millennia that some animals live in; and some animals can even stop or completely reverse the aging process.
While there are some land animals that live very long (the oldest turtle, for example, is nearly 190 years old), none of them make this list – the true champions of the age all live in the water. From oldest to oldest, here are 10 of the oldest animals in the world today.
1. Bowhead whale: potentially over 200 years old
Bowhead whales (Balaena mysticetus) are the longest-living mammals. The exact lifespan of arctic and subarctic whales is unknown, but stone harpoon points found in some harvested individuals prove that they comfortably live over 100 years and can live over 200 years, according to the National Oceanic and Atmospheric Administration. (NOAA).
Whales have mutations in a gene called ERCC1, which is involved in repairing damaged DNA, which can help protect whales from cancer, a potential cause of death. In addition, another gene, called PCNA, has a section that has been duplicated. This gene is involved in cell growth and repair, and duplication could slow aging, Live Science previously reported.
Related: Natural rates of aging are fixed, study finds
2. Redeye rockfish: over 200 years old
Quilleye rockfish (Sebastes aleutianus) are one of the longest-living fish and have a maximum lifespan of at least 205 years, according to the Washington Department of Fish and Wildlife. These pink or brownish fish live in the Pacific Ocean from California to Japan. According to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), an independent advisory committee that assesses the status of endangered species in Canada.
Related: Are the fish caught off Alaska 200 years old?
3. Freshwater pearl mussel: over 250 years
Freshwater pearl mussels (Margaritifera margaritifera) are bivalves that filter food particles from the water. They mainly live in rivers and streams and can be found in Europe and North America, including the United States and Canada. The oldest known freshwater pearl mussel was 280 years old, according to the World Wildlife Fund (WWF). These invertebrates have a long lifespan due to their low metabolism.
Freshwater pearl mussels are an endangered species. According to the International Union for the Conservation of Nature (IUCN), their population is in decline due to various human factors, including damage and changes to the river habitats on which they depend.
Related: Underwater maids: mussels and clams could mop up streams
4. Greenland shark: 272+ years
Greenland sharks (Somniosus microcephaly) live deep in the Arctic and North Atlantic oceans. According to the St. Lawrence Shark Observatory in Canada, they can reach a length of 24 feet (7.3 meters) and have a diet that includes a variety of other animals, including fish and marine mammals such as seals. .
A 2016 study of the eye tissue of Greenland sharks, published in the journal Science, estimated that these sharks may have a maximum lifespan of at least 272 years. The largest shark in this study was estimated to be around 392 years old, and researchers suggested sharks could be as old as 512 years old, according to Live Science. Age estimates have come with a degree of uncertainty, but even the lowest estimate of 272 years still makes these sharks the longest living vertebrates on Earth.
Related: No, scientists haven’t found a 512-year-old Greenland shark
5. Tubeworm: 300+ years
Tube worms are invertebrates that have a long lifespan in the cold and stable environment of the deep sea. A 2017 study published in the journal The Science of Nature found that laminate scarf, a species of tubeworm living on the ocean floor in the Gulf of Mexico, regularly lives up to 200 years, and some specimens survive more than 300 years. Tube worms have a low mortality rate with few natural threats, such as a lack of predators, which has helped them evolve to have such a long lifespan.
Related: Unlimited carpet of worms covers a strange underwater vent
6. Sea clam: more than 500 years old
Clams clams (Arctica islandica) inhabit the North Atlantic Ocean. This saltwater species can live even longer than the other bivalves on this list, the freshwater pearl mussels. According to the National Museum Wales in the United Kingdom, a clam discovered off the coast of Iceland in 2006 was 507 years old.
7. Black coral: over 4,000 years old
Corals look like rocks and colorful underwater plants, but they’re actually made up of invertebrate exoskeletons called polyps. These polyps continually multiply and replace each other, creating a genetically identical copy, which over time increases the structure of the coral exoskeleton. Corals are therefore made up of several identical organisms rather than being a single organism, such as Greenland sharks or oceanic clams, so the lifespan of a coral is more of a team effort.
Corals can live hundreds of years or more, but deep-water black corals (Leiopaths sp.) are among the longest-living corals. Specimens of black corals found off the coast of Hawaii have been measured at 4,265 years old, according to Live Science.
8. Glass sponge: more than 10,000 years old
Sponges are made up of colonies of animals, similar to corals, and can also live for thousands of years. Glass sponges are among the longest living sponges on Earth. Members of this group are often found in the depths of the ocean and have skeletons that resemble glass, hence their name, according to NOAA. A 2012 study published in the journal Chemical Geology estimated that a glass sponge belonging to the species Monorhaphis chuni was about 11,000 years old. Other species of sponges can live even longer.
Related: Arctic sponges crawl on the seabed and leave weird brown trails to prove it
9. Turritopsis dohrnii: potentially immortal
Turritopsis dohrnii are called immortal jellyfish because they can potentially live forever. Jellyfish start their lives as larvae, before settling on the seabed and developing into polyps. These polyps then produce jellyfish or free-swimming jellyfish. Mature Turritopsis dohrnii are special in that they can revert to polyps if they are physically damaged or starved, according to the American Museum of Natural History, and then later return to their jellyfish state.
Jellyfish, which are native to the Mediterranean Sea, can repeat this feat of reversing their life cycle several times and therefore may never die of old age under the right conditions, according to the Natural History Museum in London. Turritopsis dohrnii are tiny – less than 0.2 inches (4.5 millimeters) in diameter – and are eaten by other animals such as fish or may die by other means, preventing them from achieving immortality.
10. Hydra: also potentially immortal
Hydra is a group of small, soft-bodied invertebrates that look a bit like jellyfish. Like Turritopsis dohrnii, hydras also have the potential to live forever. Hydras show no signs of deteriorating with age, Live Science previously reported. These invertebrates are largely made up of stem cells, which continuously regenerate themselves through duplication or cloning. Hydras do not live forever in natural conditions due to threats such as predators and disease, but without these external threats they could be immortal.
Related: When blown, the hydra reassembles
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