Postojna cave is home to more than 150 different species among which “človeška ribica” is the most famous one. Its name would literally be translated into “human fish” but it is more known as olm or proteus, or with the other name – baby dragon. Yes, Khaleesi has already made an appointment and is visiting Slovenia soon.
It was almost 250 years ago when scientists first described the existence of this amazing creature living in an underground world of Slovenian Karst. At the time some local farmers believed that a dragon was living inside a mountain. After heavy rains, the water would flush the dragon’s offspring onto the surface where then the local farmers saw them. There were some misconceptions apparently, but the name stuck. The little dragons the farmers described were not dragon’s offspring but actual adult olms that were flushed out of their underground home (which is usually means death for the little dragons).
The olms these farmers saw, couldn’t be longer than 30 cm, which is the length of an adult olm. This makes proteus the largest cave-dwelling animal but is also the only vertebrate in Europe living exclusively underground. Its eyes are undeveloped, covered by a layer of skin, which shows its adaptation to the underground world. To get around in this world of darkness, olms uses other sensory organs – it has heightened sense of smell and the ability to sense even the weakest electric field.
Human fish can live up to 100 years and can survive without food for several years.
We can be proud that the little dragons are inhabiting our underground world, since they only inhabit extremely clean waters. On top of that, a fascinating process was going on in 2016, when we were observing how the female olm laid its egg in the aquarium and after 142 days the first baby dragon was born in front of everyone’s eyes. The event got huge media attraction, since olm is endangered species and in the wild very few hatchlings survive to adulthood. In aquarium roughly half of the eggs hatched successfully and 21 baby dragons grew up at the cave laboratory.
This are our little Slovenian heroes, the baby dragons, that can be seen in Postojna Cave. After visiting the human fish, you can discover some more of the karst region - not very far away is the stud farm, with famous Lipizzaners. On the way there you can even make a stop at Predjama Castle that is offering interesting stories of the underground world.
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