Biospeleology, also known as cave biology, is a branch of biology dedicated to the study of organisms that live in caves and are collectively referred to as troglofauna.
A 3D cross-section of the Lukina jama–Trojama cave system in the Velebit mountains of Croatia. The collection sites (1) of the shells and the single living specimen (2) of the cave-dwelling snail Zospeum tholussum are indicated.
The spider Trogloraptor marchingtoni from a cave in Oregon.
Troglofauna are small cave-dwelling animals that have adapted to their dark surroundings. Troglofauna and stygofauna are the two types of subterranean fauna. 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 troglofauna live permanently underground and cannot survive outside the cave environment. Troglofauna adaptations and characteristics include a heightened sense of hearing, touch and smell. Loss of under-used senses is apparent in the lack of pigmentation as well as eyesight in most troglofauna. Troglofauna insects may exhibit a lack of wings and longer appendages.
The microscopic cave snail Zospeum tholussum, found at depths of 743 to 1,392 m (2,438 to 4,567 ft) in the Lukina Jama–Trojama cave system of Croatia, is completely blind with a translucent shell
The cave beetle Leptodirus hochenwartii