A troglobite (or, formally, troglobiont) is an animal

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, 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

trogloxene 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."Cave Plants and Animals". 9 December Am ...

s). Land-dwelling troglobites may be referred to as

troglofauna 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 – troglofaun ...

, while aquatic species may be called

stygofauna Stygofauna are any fauna that live in groundwater systems or aquifers, such as caves, fissures and vugs. Stygofauna and troglofauna are the two types of subterranean fauna (based on life-history). Both are associated with subterranean environments ...

, although for these animals the term ''stygobite'' is preferable. Troglobites typically have

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

ary

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...

s to cave life. Examples of such adaptations include slow

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...

, reduced energy consumption, better food usage efficiency, decrease or loss of eyesight (

anophthalmia Anophthalmia, (Greek: ἀνόφθαλμος, "without eye"), is the medical term for the absence of one or both eyes. Both the globe (human eye) and the ocular tissue are missing from the orbit. The absence of the eye will cause a small bony orbi ...

), and

depigmentation Depigmentation is the lightening of the skin or loss of pigment. Depigmentation of the skin can be caused by a number of local and systemic conditions. The pigment loss can be partial (injury to the skin) or complete (caused by vitiligo). It can be ...

(absence of

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compo ...

in the

integument In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, shell, germ or rind. Etymology The term is derived from ''integumentum'', which is Latin for "a covering". In a transferred, or ...

). Conversely, as opposed to lost or reduced functions, many species have evolved elongated

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

and locomotory appendages, in order to better move around and respond to environmental stimuli. These structures are also full of

chemical A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., wi ...

tactile Tactile may refer to: * Tactile, related to the sense of touch * Haptics (disambiguation) * Tactile (device), a text-to-braille translation device See also * Tangibility, in law * Somatosensory system, where sensations are processed * CD96 CD ...

and

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

receptors Receptor may refer to: *Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a n ...

. Troglobites commonly do not survive well outside

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

s and therefore cannot travel between separate cave systems. As a result, many troglobiotic species are

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

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 Epigeal, epigean, epigeic and epigeous are biological terms describing an organism's activity above the soil surface. In botany, a seed is described as showing epigeal germination when the cotyledons of the germinating seed expand, throw off the ...

habitats, e.g.

bat Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...

s and cave swallows) or a

(a species only occurring sporadically in a

hypogean Hypogeal, hypogean, hypogeic and hypogeous (; ) are biological terms describing an organism's activity below the soil surface. In botany, a seed is described as showing hypogeal germination when the cotyledons of the germinating seed remain n ...

habitat and unable to establish a subterranean population).

Flatworms

*''Hausera, Hausera hauseri''

Mollusca

*Tumbling Creek cavesnail (''Antrobia culveri'') *Cave physa (''Physella spelunca'') *Phantom cave snail (''Cochliopa texana'') *Mimic cavesnail (''Phreatodrobia imitata'') * ''Zospeum'' *Tashan cave snail (''Trogloiranica tashanica'')

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 *''Troglokhammouanus steineri'' – Xe Bang Fai cave scorpion *''Vietbocap lao'' – Nam Lot 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 (arachnid), Chthonius'' *''Neobisium maritimum'' *''Agraecina cristiani'' - Movile Cave spider

Myriapoda

;Millipedes Sinocallipus deharvengi head

*''Causeyella'' species *''Chaetaspis aleyorum'' – Aleys' cave millipede *''Chersoiulus sphinx'' *''Desmoxytes'' *''Mammamia profuga'' *''Polydesmus subterraneus'' *''Sinocallipus'' *''Titanophyllum spiliarum'' *''Trichopetalum whitei'' *''Tingupa pallida'' *''Zosteractis interminata'' ;Centipedes *''Eupolybothrus cavernicolus'' *''Scolopocryptops troglocaudatus''

Crustacean, Crustacea

;Crayfish ;Others *''Allocrangonyx hubrichti'' – Hubricht's long-tailed amphipod *''Andhracoides shabuddin''– Guthikonda cave isopod *''Andhracoides gebaueri''– Belum cave isopod *''Androniscus dentiger'' – rosy woodlouse *''Alpioniscus strasseri'' *''Bactrurus brachycaudus'' – short-tailed groundwater amphipod *''Bactrurus hubrichti'' – sword-tail cave amphipod *''Bactrurus pseudomucronatus'' – false sword-tailed cave amphipod *''Barburia yanezi'' *''Caecidotea antricola'' – cave isopod *''Caecidotea dimorpha'' – Missouri cave isopod *''Caecidotea fustis'' – Fustis cave isopod *''Caecidotea salemensis'' – Salem cave isopod *''Caecidotea serrata'' – serrated cave isopod *''Caecidotea stiladactyla'' – slender-fingered cave isopod *''Caecidotea stygia'' – stygian cave isopod *''Cancrocaeca'' *''Cyclops vernalis'' *''Diacyclops yeatmani'' – Yeatman's groundwater copepod *''Gammarus acherondytes'' – Illinois cave amphipod *''Holoped amazonicum'' *''Lirceus usdagalun'' – Lee County cave isopod *''Macromaxillocaris'' *''Niphargus'' species *''Orcovita hickski'' *''Orcovita orchardorum'' *''Palaemonias alabamae'' - Alabama cave shrimp *''Samarplax principe'' *''Spelaeorchestia koloana'' *''Stygobromus barri'' – Barr's groundwater amphipod *''Stygobromus clantoni'' – Clanton's groundwater amphipod *''Stygobromus heteropodus'' – Pickle Springs amphipod *''Stygobromus onondagaensis'' – Onondaga cave amphipod *''Stygobromus ozarkensis'' – Ozark cave amphipod *''Stygobromus putedus'' – Wisconsin groundwater amphipod *''Stygobromus subtilis'' – subtle groundwater amphipod *''Typhlocaris''

Insecta

''See Cave insects''

Fish

*:Cave fish, List of cave fish

Amphibians

*Cave salamanders

Mammals

There are no known mammals that live exclusively in caves. Most

s sleep in caves during the day and hunt at night, but they are considered troglophiles or

s. However some fossorials which spend their whole lives underground might be considered subterranean fauna, although they are not true troglofauna as they do not live in caves.

References

{{Reflist, 24em Cave animals Lists of animals, Troglobites