New snail species with translucent shell discovered

Scientists have discovered a new snail species, with a beautifully shaped dome-like translucent shell, lurking underground in one of the world's deepest caves in Croatia.
Biologists from the Croatian Biospeleological Society and Goethe University, Frankfurt discovered the new species Zospeum tholussum in one of the 20 deepest cave systems in the world, Lukina Jama-Trojama in Croatia.
The species belongs to a genus of minute air-breathing land snails that have lost visual orientation and are considered to be true eutroglobionts, or exclusive cave-dwellers.
The miniature and fragile snail is described in the journal Subterranean Biology.
Only one living specimen was found during the expedition around the galleries of the Lukina Jama-Trojama cave system.

The animal was found at the remarkable depth of 980 metres, in an unnamed chamber full of rocks and sand and a small stream running through it.

All known species from the cave-dwelling genus Zospeum possess a limited ability to move. Their preference of a muddy habitat and the fact that they are usually located near the drainage system of the cave, in a close proximity to running water, however suggest that these animals are not exactly immobile.
Scientists hypothesise that dispersal is achieved through passive transportation via water or larger mammals.
The Lukina Jama-Trojama is the deepest cave system in Croatia and is known for its extraordinary vertical shape, long pits and great depth of minus 1,392 metres.