Human Fish Lays Eggs in Slovenian Cave Aquarium

Marine biologists in Slovenia have excitedly announced that a rare human fish, living in a special aquarium built in a deep underground cave, has laid three eggs and they’re anxiously waiting for them to hatch. You’ve never heard of the human fish? It was once believed by many to be a dragon. What is this strange creature?

The human fish is actually an aquatic salamander more commonly called an olm (Proteus anguinus). These blind salamanders are different than other amphibians in that they live, eat and breed entirely underwater. Found only in caves in the Dinaric Alps, which run along the coast of the Adriatic Sea, they got the name “human fish” because their pale skin is the same color of local Slovenians.

First discovered in the 1600s, their long bodies, stubby legs and cave-dwelling habits made many people think they were baby dragons. If that’s not strange enough, the long pink creature’s Slovenian name is močeril, which means “the one that burrows into wetness” … have fun with that one.

It gets better. Olms live up to 100 years, can survive without food for ten years and females only reproduce once every six years. That’s why biologists Primož Gnezda and Sašo Weldt at the Postojna Cave aquarium were thrilled when they recently found three eggs in their olm tank. The last time this happened was in 2013 when eggs were laid but either didn’t hatch or got eaten by olms.

To prevent that from happening again, the mother olm and eggs have been isolated and the biologists hope she lays a total of 30 to 60. Once laid, the eggs will potentially hatch in a few weeks.

Postojna Cave is the second-longest cave in Slovenia and a popular tourist site for its beauty as well as for the minimalist aquarium designed especially for the olms.

Let’s hope Mama Olm has a big brood of baby olms, baby dragons or human fish that won’t eventually need therapy for being called “the one that burrows into wetness.”