Slovenia eagerly awaits hatching of 'dragon' eggs

Slovenia's ghostly olm, a pale amphibian, has laid eggs for the first time in several years in the country's famous Postojna Cave.

“Game of Thrones” lovers are having a field day this week, as scientists at the Postojna Cave in Slovenia await the hatching of the country’s rare “baby dragons.”

The 55 eggs that prompted this week’s commotion belong to Europe’s only cave-adapted vertebrate species, called the olm. Found predominantly in Eastern European countries like Slovenia, Bosnia and Herzegovina, and Croatia, the olm is a blind cousin of North America's familiar salamander.

The olm is perfectly suited for life underground. Adult olms retain characteristics from their larval stage, which include gills and a lack of eyelids, as well as super sensitive hearing and the ability to hunt by detecting electric fields.

Given the olms' century-long lifespan, and their ability to survive without food for up to a decade, Slovenians might be forgiven for mistaking them for tiny dragons.

According to Sašo Weldt, a biologist who studies the cave's amphibious inhabitants, Slovenians first recorded seeing the olm in the 17th century. After heavy rains, the amphibians were washed up from underground, prompting locals to give them their dragonish name.

"People had never seen it and didn't know what it was," said Weldt, "During the winter time, clouds of fog often rose from the cave, so they came up with stories of a dragon breathing fire from the cave, and they thought the olms were its babies."

Yet, despite their nickname, the olm is nowhere near as awe-inspiring as the dragons of legend.

Olms can grow up to 200-250 millimeters, or about seven to ten inches, at their largest.

Since the pale cave dwelling creature only reproduces once every six or seven years, tourists and scientists alike were excited when the so-called mother dragon began to lay eggs toward the end of January.

Don’t get too excited about the dragon hatching, though. It could take up to another four months for the olm eggs to hatch. With a water temperature of 11 degrees Celsius, olm eggs take up to 120 days to hatch. The water temperature in Postojna Cave is 9 degrees.

Translucent eggs allow biologists to watch the development process up close.

"[We saw] what we had waited and hoped for all along – the olms' embryonic development with visible cell division,” said biologist Lilijana Bizjak. “To put it simply: it looks like the little 'dragons' are growing."

Even after four months, hatching is a risky business. Biologists at the cave are only allowing the mother olm to have access to her eggs at the moment of birth. The last time a female olm laid eggs at the cave, all were lost to cannibalism before they could hatch.

Still, Weldt and his fellow scientists are trying their best. "This time, we've removed all the other olms to make sure [the eggs] don't get eaten again," ABC News reports Weldt as saying. "We're hopeful for a successful birth."

The government of Slovenia considers the olm a “national treasure,” and the Postojna cave is a highly trafficked tourist attraction.

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