How old is the olm?

[Frog News]

AJC's Frogroom (UK) January 26th, 2011 11:08 AM: How old is the olm?

The blind cave-adapted salamander Proteus anguinus has a very long lifespan – possibly as long as a century – apparently without evidence of age-related deterioration. Also known as the 'olm' or 'human fish', a breeding population of P. anguinus was protected in a cave in south-western France near Moulis, which is better known for its ancient churches and vintage Haut-Médoc. For nearly 60 years, this population has thrived in its leisurely way, maturing at about age 15 years and ovipositing about every 12.5 years, with an annual adult mortality of 1.6% which did not appear to increase after age 40. The oldest age documented in the population was 48, but some collected while immature are probably about 58.

There is no hint of accelerating mortality in adults that would indicate senescence. Extrapolating from this unchanging mortality up to about age 50, the authors estimate a life expectancy at age 6 for the olm of 68.5 years. Voituron and colleagues used the ratio between life expectancy and maximum recorded longevity in other species to estimate a 100 year maximum lifespan for a population of 400 animals. This estimated maximum lifespan of a 15–20 g adult surpasses the predicted longevity of other amphibians based on allometric equations correcting for body mass. The giant salamanders of China and Japan (Andrias davidianus and A. japonicus) which weigh 25–60 kg, 1,000-fold more than the olm, are also reputed to live more than 50 years, however, there is no Andrias population for which adult mortality statistics can be calculated. Evidently, under protected conditions, gigantism is not needed for great longevity. It would not be surprising if some frogs could survive at least as long as the salamanders, big and small. Unfortunately, no adult population has been established for adult longevity and we are left with a few reports from zoos that some frogs and toads can live beyond 30 years.


Blind cave salamanders age very slowly: A new member of Methuselah's Bestiary. (2011) BioEssays 33(1): 1521-1878 doi 10.1002/bies.201000111

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