Scientists believe they have found why some animals don’t seem to age. A new study has found that turtles, salamanders and crocodiles age very slowly. Members of a few species, including frogs, toads and turtles age at a negligible rate or hardly at all.
Scientists say the key to the animals’ longevity is their protective features such as a turtle’s shell. An armor makes an animal less likely to be eaten, and because they are likely to live for many decades it makes evolutionary sense for them to age more slowly. This is the so called the protective phenotype hypothesis.
The study gathered data on 107 populations from 77 species all living in the wild, and while its findings could help us learn more about humans age, they are not likely to have an impact on how humans’ lives. These are four animals with long lifespans.
1. Immortal Jellyfish
It is a species of small jellyfish found worldwide in temperate to tropic waters. It is one of the few known cases of animals capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary individual. They start their life as larvae, known as planula. Later they settle on the seafloor and become static polyps before transforming into swimming medusa. If at any stage immortal jellyfish experience injury or stress from changes in their environment, they can go backwards to the polyp stage and start again.
2. Ocean Quahog
The ocean quahog is a bivalve mollusk that lives buried in sandy seabeds. It is a filter feeder, filtering organic matter from the water column using its siphon. Often, the siphon is all that is visible above the seabed and the end is sometimes nibbled off by hungry cod. They are very slow growing and extremely long-lived – with individual clams living for hundreds of years.
Age: Many will live until 400 years and the oldest one on record was 507 years-old.
3. Greenland Shark
Greenland sharks are top predators and eat a variety of fishes, invertebrates, and other prey. According to the Oceana.org, dissected individuals have even had the remains of polar bears, reindeer, horses, and other large land mammals in their digestive systems. It is unclear whether these individuals had eaten live prey that fell into the water or if they scavenged dead animals, but Greenland sharks are known to live at the ice edge and to live at the sea surface.
Age: Greenland sharks live for between 300 and 500 years and are the longest-living vertebrate.
4. Bowhead Whale
Bowhead whales are capable of breaking through sea ice at least seven inches thick with their large skulls and powerful bodies. According to World Wildlife, these whales can grow up to 60 feet long while still being able to leap entirely out of water. Bowheads filter their food through baleen by opening their mouths and straining plankton from the surface, the water column, or the sea floor. Data has shown that bowhead whales may be among the longest-lived animals on earth.
Age: Bowhead whales can live for over 200 years, which is longer than any other mammal.
