Scientists at an underground aquarium in Slovenia face a tense wait, as eggs laid by the olm - a rare type of blind salamander - are expected to hatch in the next few days.
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The olm - also known as the proteus - is a bizarre-looking amphibian that has dwelled in the cave rivers of the Balkans for millions of years. They're thought to live for more than 100 years but reproduce just once or twice a decade.
A female olm has laid around 50 eggs at the aquarium at the Postojna Cave - and three of them are now showing signs of growth.
Saso Weldt, a biologist employed 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."
The proteus is famous in Slovenia, even appearing on coins before the euro arrived. Hundreds of years ago, when floods washed the creatures from the caves, they were believed to be baby dragons.
Aquarium workers have added extra oxygen to the water, removed everyone but the mother olm from the tank, and boarded up the aquarium to protect the eggs from light.
"Now it's up to them," said Mr Weldt.