From Eggs to Juveniles

It has been a year since the moment that astonished and thrilled us, since the monumental event that marked the entire Postojna year and attracted a lot of attention all around the world. On Saturday, 30 January 2016, the first laid olm egg was noticed on the glass of Postojna Cave's aquarium. 


On the anniversary of this event, Marjan Batagelj, Chairman of the Management Board of the company Postojnska jama d. d., and Katja Dolenc Batagelj, Executive Marketing Manager and head of the team and the laboratory taking care of the 21 olm juveniles, presented the course of events in the past year, as well as the plans and expectations for the future.

If you click on this link, you can watch a 24-second morph video that presents the exciting year that was 2016 and the most important events in the development of eggs, hatchlings and, now, eight-month-old olms.  

The video is composed of rare olm photos that were, by way of documenting the olms' life, taken every month. You can clearly see how the legs and the digits have developed, as well as the head, which was initially round and short, but is now shaped more like an elongated trapezoid with a snout resembling a duck's beak. The body is becoming increasingly long and slender. To sum it up, the olm juveniles are becoming more and more similar to their "dragon mum". Another thing that that sets them apart from the mother are two black eyes – which will remain visible until the olms are 2-3 years old, when they will get covered by a layer of skin – as well as pigmentation. In fact, "baby dragons" (as the olms have been nicknamed) are grey in colour. Almost their whole bodies, except the abdominal part, are covered in tiny dark specks, chromophores, which will gradually disappear by the time they turn 18 months. Then, the olm juveniles' colour will become pink. At the beginning, the olms were rather helpless, lying on the side and living on yolk stored in the abdominal area, and now they are proper little predators that can polish off their prey in a second.  


According to experts, the result of hatching and the hatchlings' survival rate is extraordinary; by creating optimum conditions and through its dedicated care for the baby dragons, the Postojna cave laboratory has made a significant contribution to olm-related knowledge. This is a ground-breaking achievement in terms of successful olms' breeding in captivity and constitutes a departure from the cave laboratory paradigm that was used for decades, but has proven to be less successful.


In talking about the "baby dragons" to the press, Marjan Batagelj and Katja Dolenc Batagelj presented the experts' opinion about the release of olm juveniles into the natural environment and the related risks. Since these are animals that have been developing and growing up in an optimal man-made environment, releasing them into the wild may pose a risk. They would most likely not survive in the natural environment and their microbiota could endanger the olms’ native population.