Cave salamander sheds light on ageing

21 July 2010

A bizarre cave-dwelling creature could be about to revolutionise the science of ageing.  New research, published in the Royal Society journal Biology Letters, suggests that the olm – a blind amphibious salamander more correctly known as Proteus anguinus – seems to defy all predictions offered by current theories of ageing.

The snakelike olm spends its life underwater in the darkness of Slovenian and Croatian caves and is virtually sightless.   While organisms that have adapted to life in the dark are known throughout the world, P. Anguinus is Europe’s only committed cave dwelling vertebrate.  However, the most extraordinary thing about this rather odd-looking creature is its incredible longevity - it has an average lifespan of 68.5 years but can live for up to 100 years.

Previous studies have suggested that marked longevity in the animal kingdom tends to be associated with a large body size.  However, olms are relative small – average body size tends to be around 20-30cm – and although they do enjoy a stable, relatively predator-free environment, there are further paradoxes associated with their longevity.

As well as body size, a slow metabolic rate has also been found to be correlated with a long lifespan.  Some scientists have suggested that this is because the by-products of metabolism cause damage to an organism, which builds up over the course of its life.  So, if reducing metabolic rate isn’t an option, some animals might develop mechanisms to slow or repair this damage and thus slow the ageing process leading to longer lives. 

However, the researchers found to their surprise that the olm has a completely ordinary metabolic rate for an amphibian, and doesn’t have any mechanisms to repair the damage caused by metabolic by-products – meaning that the cause of its extraordinary longevity remains a mystery.  

The physiological factors behind the ageing process are obviously of immense importance; if we can understand what causes the body to age, we might be able to start looking into how to prevent or delay the onset of old age.  So, if further research can uncover the secrets behind the olm’s extraordinary persistence, it’s just possible that we might be a step closer to unlocking the secrets of eternal youth.