Cave animals

thumb|The microscopic cave snail Zospeum tholussum|Zospeum tholussum, found at depths of in the Lukina Jama–Trojama cave system of [[Croatia, is completely blind with a translucent shell]] Troglofauna are small cave-dwelling animals that have adapted to their dark surroundings. Troglofauna and stygofauna are the two types of subterranean fauna (based on life-history). Both are associated with subterranean environments – troglofauna are associated with caves and spaces above the water table and stygofauna with water. Troglofaunal species include spiders, insects, myriapods and others. Some

animal species adapted to live in an underground environment

thumb|right|240px|Astyanax jordani, a [[cavefish from Mexican caves]]

Trogloxenes or subtroglophiles, also called cave guests, are animal species which periodically live in underground habitats such as caves or at the very entrance, but cannot live exclusively in such habitats. Among many scientists, trogloxenes and subtroglophile have slightly different but closely related meanings, with the former covering species that are occasional visitors to underground habitat and the latter species that live more permanently there, but have to go outside (for example, to find food). Both these are in contrast to troglobites, which strictly live in underground habitats.