A slower pace of life is behind the longevity of the world’s oldest ever animal, the Ocean quahogs
What is an ocean quahog?
At first sight, though, an ocean quahog is just a fairly plain, quite large and rounded clam. As with all clams, its shell is made up of two hinged parts called valves that protect the soft body parts inside. When fresh and alive, the ocean quahog is covered in a dark, skin-like layer called the periostracum, so it’s also known as a black or mahogany clam.
How big are ocean quahogs and where do they live?
Older ocean quahogs can be over 5cm thick and 13cm long. Empty shells washed up on the shore are probably the closest most of us will get to seeing one, as the living animals bury themselves in sediment 4-500m underwater.
What do ocean quahogs eat?
Ocean quahogs, like nearly all clams, are filter feeders. In the cool waters off our North Atlantic shores, they get on with the slow, steady and unexciting occupation of filter feeding. This involves sucking in water through their inhalant siphon. A current generated by thousands of tiny, beating hairs, called cilia, pulls this water into a clam’s gill cavity.
One specimen made the news in 2006 when it was dredged up off the coast of Iceland by
a Bangor University expedition. This large ocean quahog turned out to be the oldest known individual ever discovered, and the oldest substantiated animal on Earth. It was nicknamed Ming, as the Chinese dynasty of the same name was coming into power at the time the mollusc was born and settled on the ocean floor, some 507 years ago
Unfortunately, Ming was frozen and preserved in the name of science (the researchers regret this) so we have no idea how old these creatures can get. We do know, however, that animals like the ocean quahog exhibit a rare phenomenon known as negligible senescence. This means they don’t seem to show any signs of ageing as they get older, maintaining bodily and reproductive fitness. This humble mollusc starts slow, matures in about eight years and then, as its metabolic costs are minimal, it just ticks over in cool northern waters.
