Scientists have discovered a new species of snail, the likes of which have never been seen before.

Found lurking some 3,000 feet down in the Lukina Jama-Trojama cave system in Croatia, the snail boasts a completely translucent shell.

A team of cavers and biologists from the Croatian Biospeleological Society collected eight shells during a caving expedition before handing them over to taxonomist Alexander Weigand at Goethe-University in Frankfurt Germany for identification.

Realizing the shells belonged to a yet unidentified species, Weigand proceeded to analyze the specimens dubbed Zospeum tholussum.

According to the study detailing the discovery, the new species is related to Zospeum amoenum, "but can but can be readily distinguished from the latter by the presence of a weak columellar fold and its dome-like structured 2nd whorl."

The shells, described as smooth and thin, were discovered in an area littered with rocks, sand and a nearby stream. Air temperatures hovered in the high 30s Fahrenheit at the collection site, with humidity pushing 100 percent.

Currently, the new species has not been spotted anywhere besides the Lukina Jama-Trojama cave system, though Weigand notes the system is located within the distribution range of the related Zospeum amoenum, which dwells in caves found in the West Balkan of North Slovenia, West Croatia, Bosnia and Herzegovina and south of Montenegro. For this reason, the researcher hypothesizes that a number of the distribution records for Zospeum amoenum may in fact refer to Zospeum tholussum.

According to Weigand, the snail is extremely slow-moving -- even for a snail.

"They only creep a few millimeters or centimeters a week, and mainly in circles, grazing at one point where they live," LiveScience reports the researcher as saying.

Weigand says he suspects the snails use water currents or hitch a ride on other animals in order to move around quickly.

Going forward, the researcher says "the intraspecific genetic and conchological variability of the new species should be investigated in greater detail, thus to judge about the taxonomic information content of the diagnostic characters applied within this description."