ORIGINAL: Discover Magazine
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| The olm is a blind, cave-dwelling salamander, also called the proteus and the “human fish”, for its pale, pinkish skin. It lives in caves in Eastern Europe. Photo by Arne Hodalič |
In the caves of Slovenia and Croatia lives an animal that’s a cross between Peter Pan and Gollum. It’s the olm, a blind, cave-dwelling salamander, also called the proteus and the “human fish”, for its pale, pinkish skin. It has spent so long adapting to life in caves that it’s mostly blind, hunting instead with various supersenses including the ability to sense electricity. It never grows up, retaining the red, feathery gills of its larval form even when it becomes sexually mature at sweet sixteen. It stays this way for the rest of its remarkably long life, and it can live past 100.
The olm was once described as a baby dragon on account of its small, snake-like body. It’s fully aquatic, swimming with a serpentine wriggle, while foraging for insects, snails and crabs. It can’t see its prey for as it grows up, its eyes stop developing and are eventually covered by layers of skin. It’s essentially blind although its hidden eyes and even parts of its skin can still detect the presence of light. It also has an array of supersenses, including heightened smell and hearing and possibly even the ability to sense electric and magnetic fields.
The caves of Slovenia and Croatia have provided the olm with safe haven for over 20 million years, but these unchanging habitats are changing quickly. Chemical pollutants leaching into the caves and the attentions of eager black market collectors have seriously hit the olm population, and it is now vulnerable to extinction. Scientists have risen to the challenge by setting up various “cave laboratories” throughout Europe to save and study this iconic species at the same time.
One such laboratory lies in Moulis, France. In 1952, a group of scientists set up several riverbed-like basins in a local cave to mimic the olm’s natural habitat. The animals are protected and regularly fed. Sixty years on, there are more than 400 individuals in the cave, making it the only successful olm breeding programme in the world. And ever since 1958, researchers have been recording births and deaths among the olms on a weekly basis. Thanks to their painstaking census, we now have a unique glimpse into this odd creature and how it lives as long as it does.
Yann Voituron from the University of Lyon has analysed the five decades of data and found that the oldest olms are around 48-58 years old. Still, they show no sign of age-related physical decline. Based on the adults’ survival rates, Voituron calculated that the species lives to an average age of 69 years, supporting reports of captive olms living to 70.
