Clearly new snail

Croatia’s deepest cave system is home to a tiny, translucent resident

DEEP DOWN A tiny, translucent snail lives in Croatia’s deepest cave system.

D. Bakšić, Croatian Speleological Server 2010

Croatia’s deepest cave system is home to a tiny, translucent resident. The newly named Zospeum tholussum belongs to a group of terrestrial snails found in wet subterranean habitats. Alexander Weigand of Goethe University Frankfurt in Germany retrieved a living specimen from one chamber and a handful of empty shells from others more than 800 meters deep inside the Lukina Jama–Trojama cave system.

At that depth, air temperature drops to a chilly 3.3° Celsius. The delicate shells averaged just 1.55 millimeters tall, or about the thickness of a penny. Unoccupied shells are nearly clear but turn milky white as they age, Weigand reported in August in Subterranean Biology.

A living snail of the new species was found 800 meters below ground and shells of the animals were found almost 1,400 meters down. Jana Bedek, HBSD, Adapted by S. Egts