The Longest Lived Animal on Earth, The Ocean Quahog, Arctica islandica

William and Mary were on the throne of England when this animal hatched from its egg over 310 years ago, but it is not the oldest.

One dredged up off the coast of Iceland had a life covering 507 years!

Arctica Islandica
Arctica Islandica

These clams can be found around the North Atlantic continental shelf seas, including the coast of Britain and Ireland, Scandinavia, Spitsbergen, North America from Cape Hatteras to Newfoundland, and Iceland.

Their shells are a hidden archive. Analysing the growth rings can show us what past climates were like. Narrow gaps between rings indicate slow growth for that year, whilst wide gaps show rapid growth. All individuals of the same age show similar patterns which means they were responding to the same environmental conditions (how much food was around, the temperature of the water). The shells can tell us a lot. Measuring the isotopes of oxygen and carbon tells us the sea temperature and salinity which in turn can be used to estimate the prevailing climate. The presence and quantities of substances like calcium, strontium, magnesium, boron, zinc etc, can help us understand levels of marine pollution over time and ocean acidification.

What is also intriguing is the very fact that they can live so long without senescing. They seem to switch-off the aging genes and if not eaten might in fact live for ever! Understanding how they do this will help us understand the aging process, a key part of which in us is the development of tumours and deterioration of tissues like muscles which these creatures do not experience. If we had such genes just think what it could mean … !

Gerald Legg, Keeper of Natural Sciences

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