Iztok Medja/Postojnska jama

Super-rare 'dragon eggs' are about to hatch in a Slovenian cave

We’re watching a once-in-a-decade event unfold.

BEC CREW
1 MAR 2016
 

A rare amphibian is fiercely guarding a clutch of around 50-60 eggs in a water-logged cave near Postojna in southwestern Slovenia, and biologists are nervously anticipating babies.

Nicknamed dragons because of their long, serpentine bodies, olms are a species of blind, aquatic salamanders that eat, sleep, and breed entirely underwater. Despite having a lifespan of around 100 years, olms only lay eggs once or twice a decade, making what’s about to happen a very, very special event.

 

While we’ve got up to 60 eggs to pin our hopes on, biologists on the scene suspect that only a few will end up hatching, and it’s anyone’s guess as to when that will happen, and how long it will actually take.

"Right now it looks like three are good candidates," Saso Weldt, a biologist working at the cave, told the BBC. "She started laying eggs on 30 January. She is still laying one or two eggs per day, and they need something like 120 days till they hatch."

Three babies from 60-odd eggs might sound like a pretty dismal result, but thanks to an aquarium that’s been built inside the Slovenian olm cave, these creatures have been given the best chance of survival, away from the predators, pollution, and temperature fluctuations that other olm families have to deal with. 

They’re now being monitored around the clock by a team of researchers that are definitely not going to let any rival olms ruin the event like they did back in 2013. As Jonathan Webb reports for the BBC, another of Postojna's captive olms laid eggs three years ago, but none of them hatched, and the fact that other olms ate a bunch of them certainly didn’t help. 

This time around, the mother olm - known locally as Dragon Mum - has been isolated, and is being fed extra oxygen for good measure. "This is very cool - it is quite extraordinary," said Primoz Gnezda, a biologist working at Postojna Cave. "But also, we are quite scared that something will go wrong, because the eggs are very sensitive."

It’s not only going to be an incredible thing for us to witness if Dragon Mum does end up having live, healthy offspring, it’s going to be a real boon for biologists who study the elusive species. Everything we think we know about what will happen with those eggs - which isn’t much - is based on a single colony of olms that was established in an underground lab in the French Pyrenees more than 60 years ago.

"It is very significant because there is not a lot of data about anything, [relating to] the reproduction of this group of animals," olm expert Dusan Jelic from the Zoological Society of London told the BBC

Best of luck, Dragon Mum and future babies, we're rooting for you!

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