By the findings of cave bear bones, the Križna jama cave ranks among the richest caves in this part of Europe. It served as a den to cave bears for tens of thousands of years, but today only smaller animals live inside.
Even though the water lacks nutrients, the cave is rich with troglobites, specialised cave dwellers. The 45 troglobite species found here make the Križna jama the fourth most biodiverse cave in the world.
Sideswimmer Niphargus orcinus and shrimp Monolistra rakovitzai were first described after the very specimens from the cave. In addition, the cave hosts six species of freshwater snails, of which three are native species belonging to Belgrandiella genus. The eternal darkness of the Križna jama is also home to the narrow-necked blind cave beetle, the first described cave insect in the world, white titanic bug, cave spider and sideswimmer Nyphargus stygius.
The entrance to the cave also serves as shelter to other animals, among them are tissue moths and cave crickets, whereas horseshoe bats rest a bit deeper.
| Number or troglobite species: | 45 |
| Number of native species: | 2 |
| Number of species described in the Križna jama cave: | 2 |