"The vivarium" Top 5 Page for this destination Postojna Things to Do Tip by JLBG

Postojna cave is visited every day by several thousands visitors. In the mean time, the vivarium is visited by a few dozens, may be one hundred of visitors. Even if that was several hundreds, that would mean that only one out of ten visitors comes to the vivarium which is really a pity.

The vivarium presents several dozens of troglobites (= cave dwellers) ie animals that live permanently in caves, trogloxenes (= cave guests) , ie animals that dwell in caves but feed in the open and troglophiles (= cave lovers), ie animals that sometimes live in caves but also live elsewhere.

Along the generations, troglobites have adapted to cave life and have lost any pigments in their skin and usually their eyes. The masterpiece of Postojna vivarium is of course the famous Proteus (Proteus anguineus), named cave salamander or olm in English.

The Proteus is a blind amphibian. It is 15-30 cm long with two pairs of small legs. As it is not pigmented, the color of the blood shows through the skin and the body is pale pink, almost human color. This is why it is also named human fish. It has two outside gills, bright red. It lives in the cave ponds of Postojna and of most caves of the Dinaric Karst in the eastern Adriatic : Italy, Slovenia, Croatia, Bosnia-Herzegovina and Montenegro. As there is very little food in the caves, it eats neither much not often. In laboratory experiments, it has been found that it could live without food for as long as 12 years! With little food, it grows very slowly. It can live up to 100 years.

The olm was first mentioned in a book written in 1689 and was considered as a baby dragon. It has sometimes been represented with wings, corresponding to the gills. It was first scientifically studied and described in 1768 when an Austrian scientist, Josephus Nicolaus Laurenti gave it the name of Proteus anguineus.

The olm has been protected since 1922. It is now on the list of rare and endangered species. The caves where live the olm are protected under the rules of the Natura 2000 network. It is forbidden to collect and sell them. They can be picked only for controlled scientific purposes. Some olms have been introduced for studies in caves for example in France (Choranche and Moulis) and Belgium (Han-sur-Lesse).

More about Proteus anguinus on Istrianet web site that give several links for those interested.

It is forbidden to take any photo in the vivarium. The light is dim and not enough for a photo. Repeated flashes would harm the animals and especially the olm. This is why I have no photo of the olm.

Photo 1 is a close up on the olm painted over the entrance of the vivarium.

Photo 2 shows the entrance into the vivarium.