A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live underground (eutroglophiles), and species that are only cave visitors (subtroglophiles and trogloxenes). Land-dwelling troglobites may be referred to as troglofauna, while aquatic species may be called stygofauna, although for these animals the term stygobite is preferable.
Troglobites typically have evolutionary adaptations to cave life. Examples of such adaptations include slow metabolism, reduced energy consumption, better food usage efficiency, decrease or loss of eyesight (anophthalmia), and depigmentation (absence of pigment in the integument). Conversely, as opposed to lost or reduced functions, many species have evolved elongated antenna and locomotory appendages, in order to better move around and respond to environmental stimuli. These structures are also full of chemical, tactile and humidity receptors. Troglobites commonly do not survive well outside caves and therefore cannot travel between separate cave systems. As a result, many troglobiotic species are endemic to a single cave or system of caves.
Not all cave dwelling species are considered to be troglobites. An animal found in an underground environment may be a troglophile (a species living both in subterranean and in epigean habitats, e.g. bats and cave swallows) or a trogloxene (a species only occurring sporadically in a hypogean habitat and unable to establish a subterranean population).
Flatworms
Hausera hauseri
Mollusca
Foushee Cavesnail (Amnicola cora) Angustopila psammion Tumbling Creek cavesnail (Antrobia culveri) Manitou cavesnail (Antrorbis breweri) Cecilioides Phantom cave snail (Cochliopa texana) Peck's cave snail (Glyphyalinia pecki) Maitai Cave snail (Hadopyrgus ngataana) Laoennea renouardi Neritilia mimotoi Mimic cavesnail (Phreatodrobia imitata) Cave physa (Physella spelunca) Pisulina maxima Tashan cave snail (Trogloiranica tashanica) Zospeum tholussum
Velvet worms
White cave velvet worm (Peripatopsis alba) Speleoperipatus spelaeus
Arthropoda
Arachnida
Kauaʻi cave wolf spider (Adelocosa anops) Nelson cave spider (Spelungula cavernicola) Calicina cloughensis Texella reddelli Trogloraptor marchingtoni Apochthonius mysterius – Mystery Cave pseudoscorpion Apochthonius typhlus – Stone County cave pseudoscorpion Hesperochernes occidentalis – guano pseudoscorpion Mundochthonius cavernicolus – cavernicolous pseudoscorpion Phanetta subterranea – cave spider Porrhomma cavernicola – cavernicolous Porrhomma spider Porrhomma rosenhaueri – A blind cave Spider (very rare) Sinopoda scurion – eyeless huntsman spider Aops oncodactylus – Barrow Island cave scorpion Troglokhammouanus steineri – Xe Bang Fai cave scorpion Vietbocap lao – Nam Lot cave scorpion Hormurus polisorum – Christmas Island cave scorpion Parobisium yosemite – Yosemite cave pseudoscorpion Titanobochica magna – cave pseudoscorpion Cicurina madla – Madla Cave meshweaver Chinquipellobunus madlae – cave harvestman Stalita taenaria Mesostalita nocturna Chthonius Neobisium maritimum Agraecina cristiani - Movile Cave spider