A new species of snail has been discovered 3,000 feet below the ground, in some of the world's deepest known cave systems in Croatia. The snail's strange characteristics have left scientists in awe, as the snail has a glassy, see-through shell.

The species was discovered by some spelunkers and biologists, who have descended into the Lukina Jama-Trojama cave systems in the west of Croatia (which is among 20 of the deepest cave systems in the world) during an expedition in which the objective was to measure the full depth of the cave. The explorers took the chance to collect animal samples along the way, as underground crevices are often places from which to discover several new species. They then discovered the snail, taking with them one live sample, and eight empty shells.

The elegant little critter was sent, along with the shells, to the Goethe University in Frankfurt, Germany, to be examined by a taxonomist, Alexander Weigand. He has identified the snail had never been discovered before, but that it was related to many already discovered species of snail. The new species have since been called Zospeum tholussum.

The Zospeum tholussum does not have eyes or shell pigmentation, as such qualities are completely unnecessary for living inside the total darkness of a cave thousands of feet underground. The snail (and its relative species) is also considered to be a slow bunch, even for snails, milling about only a few centimeters or millimeters per week, and in circles, staying mainly around specific areas, where all they do is graze.

So, if it takes them weeks to make a full circle, does it take them millions of years for their population to grow?

Weigand says that the snails hitch rides on water currents or other cave creatures like bats to travel to other grazing grounds.

See more information (if you can stand all the scientific jargon) and pictures of these beautiful little snails in their natural habitat, in the scientific journal Subterranean Biology.