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