View source for Fauna

{{short description|Set of animal species in any particular region and time}}
{{other uses}}
{{redirect|Animal Life|the book|Animal Life (book)}}
{{Refimprove|date=April 2012}}
[[File:Fauna.png|frame|right|Simplified schematic of an island's fauna – all its animal species, highlighted in boxes]]

The '''Fauna''' ({{plural form}}: '''faunae''' or '''faunas''') is the whole of [[animal]] [[life]] present in a particular region or time. The corresponding terms for [[plant]]s and [[fungi]] are ''[[flora]]'' and ''[[funga]]'', respectively. Flora, fauna, funga and other forms of life are collectively referred to as ''[[Biota (ecology)|biota]]''. [[Zoologist]]s and [[paleontologist]]s use ''fauna'' to refer to a typical collection of animals found in a specific time or place, e.g. the "[[Sonoran Desert]] fauna" or the "[[Burgess Shale]] fauna". [[Paleontology|Paleontologists]] sometimes refer to a sequence of [[faunal stage]]s, which is a series of rocks all containing similar fossils. The study of animals of a particular region is called '''faunistics'''.

== Etymology ==
''[[:wikt:fauna|Fauna]]'' comes from the name [[Fauna (deity)|Fauna]], a Roman goddess of earth and fertility, the Roman god [[Faunus]], and the related forest spirits called [[Faun]]s. All three words are cognates of the name of the Greek god [[Pan (god)|Pan]], and ''panis'' is the [[Modern Greek]] equivalent of fauna (πανίς or rather πανίδα). ''Fauna'' is also the word for a book that catalogues the animals in such a manner. The term was first used by [[Carl Linnaeus]] from Sweden in the title of his 1745<ref>[[Wikisource:1911 Encyclopædia Britannica/Linnaeus]]</ref> work ''Fauna Suecica''.

== Subdivisions on the basis of region ==
=== Cryofauna ===
''Cryofauna'' refers to the animals that live in, or very close to, cold areas.

===Cryptofauna===
''Cryptofauna'' is the fauna that exists in protected or concealed [[microhabitats]].<ref>[http://www.nova.edu/ncri/11icrs/proceedings/files/m26-04.pdf NCRI]</ref>

=== Epifauna ===
Epifauna, also called ''epibenthos'', are aquatic animals that live on the bottom substratum as opposed to within it, that is, the [[benthic]] fauna that live on top of the sediment surface at the seafloor.

=== Infauna ===
[[File:Bioturbation-in-a-Declining-Oxygen-Environment-in-situ-Observations-from-Wormcam-pone.0034539.s002.ogv|right|thumb|This [[Time-lapse photography|time-lapse]] movie shows images taken every hour during a two-week period. Worms, bacteria and fish are shown [[Bioturbation|disturbing the sediment]] as they burrow and move through it.]]
''Infauna'' are [[Benthic zone|benthic]] organisms that live within the bottom substratum of a water body, especially within the bottom-most oceanic sediments, the layer of small particles at the bottom of a body of water, rather than on its surface. [[Bacteria]] and [[microalgae]] may also live in the interstices of bottom sediments. In general, infaunal animals become progressively smaller and less abundant with increasing water depth and distance from shore, whereas bacteria show more constancy in abundance, tending toward one million cells per milliliter of interstitial seawater.

Such creatures are found in the fossil record and include [[lingulata]], [[Trilobite|trilobites]] and [[Worm|worms]]. They made burrows in the sediment as protection and may also have fed upon detritus or the mat of microbes which tended to grow on the surface of the sediment.<ref>
Infauna organisms in hydrothermal environments have developed adaptive strategies to survive harsh conditions, such as extreme temperatures, low pH levels, and reduced salinity. They constructed galleries, with the highest abundance in H1, and the dominant classes, Malacostraca and Polychaeta, demonstrating mobility-based strategies like burrowing or crawling. These strategies help infauna cope with hydrothermal influence.” (Rodriguez Uribe 2023). hydrothermal influence refers to the transformative effects of hot water on geological, chemical, and biological systems, and it plays a significant role in a wide range of natural processes and human activities. 
{{citation|last=Vermeij|first=Geerat|title=Nature: An Economic History|year=2009|publisher=Princeton University Press|isbn=9781400826490}}. p. 266</ref> Today, a variety of organisms live in and [[Bioturbation|disturb the sediment]]. The deepest burrowers are the ghost shrimps (''[[Thalassinidea]]''), which go as deep as {{convert|3|m|0}} into the sediment at the bottom of the ocean.<ref>{{citation|last=Vermeij|first=Geerat|title=Nature: An Economic History|year=2009|publisher=Princeton University Press|isbn=9781400826490}}. p. 267</ref>

=== Limnofauna ===
''Limnofauna'' refers to the animals that live in fresh water.

=== Macrofauna ===
''Macrofauna'' are [[benthic]] or soil organisms which are retained on a 0.5&nbsp;mm sieve.  Studies in the deep sea define macrofauna as animals retained on a 0.3&nbsp;mm sieve to account for the small size of many of the taxa.

=== Megafauna ===
{{Main article|Megafauna}}[[File:Australisk fauna, Nordisk familjebok.jpg|thumb|right|upright=1.35|[[Fauna of New Guinea|Papuan]], [[Australian fauna|Australian]] and [[Fauna of New Zealand|New Zealand fauna]]. This image was likely first published in the first edition (1876–1899) of the {{lang|sv|[[Nordisk familjebok]]}}.]]

''Megafauna'' are large animals of any particular region or time. For example, [[Australian megafauna]].

=== Meiofauna ===
{{Main article|Meiobenthos}}
''Meiofauna'' are small [[benthic]] [[invertebrate]]s that live in both marine and freshwater [[Ecosystem|environments]]. The term ''meiofauna'' loosely defines a group of [[organism]]s by their 
size, larger than microfauna but smaller than macrofauna, rather than a taxonomic grouping. One environment for meiofauna is between grains of damp sand (see [[Mystacocarida]]).

In practice these are metazoan animals that can pass unharmed through a 0.5–1&nbsp;mm [[mesh]] but will be retained by a 30–45&nbsp;μm mesh,<ref>[https://www.iopan.gda.pl/rbdo/mekodb/litus/meiofauna.html Fauna of Sandy Beaches]</ref> but the exact dimensions will vary from [[research]]er to researcher. Whether an organism passes through a 1&nbsp;mm mesh also depends upon whether it is alive or dead at the time of sorting.

=== Mesofauna ===
{{Main article|Soil mesofauna}}
''Mesofauna'' are macroscopic soil animals such as [[arthropod]]s or [[nematode]]s. Mesofauna are extremely diverse; considering just the springtails ([[Collembola]]), as of 1998, approximately 6,500 species had been identified.<ref>{{cite journal|title=Biodiversity of Collembola and their functional role in the ecosystem|author=Josef Rusek|journal=Biodiversity and Conservation|year=1998|volume=7|issue=9|pages=1207–1219|doi=10.1023/A:1008887817883|bibcode=1998BiCon...7.1207R |s2cid=22883809}}</ref>

===Microfauna===<!-- This section is linked from [[Microfauna]] -->
{{Main article|Microfauna}}

Microfauna are microscopic or very small animals (usually including [[protozoa]]ns and very small animals such as [[rotifer]]s). To qualify as part of the microfauna, an organism must exhibit animal-like characteristics, as opposed to [[microflora]], which are more plant-like.

=== Stygofauna ===
{{Main article|Stygofauna}}
Stygofauna is any fauna that lives in [[groundwater]] systems or aquifers, such as [[cave]]s, fissures and [[vug]]s. Stygofauna and [[troglofauna]] are the two types of [[subterranean fauna]] (based on life-history). Both are associated with subterranean environments – stygofauna is associated with water, and troglofauna with caves and spaces above the [[water table]]. Stygofauna can live within freshwater [[aquifer]]s and within the [[wiktionary:pore|pore]] spaces of [[limestone]], [[calcrete]] or [[laterite]], whilst larger animals can be found in cave waters and wells. Stygofaunal animals, like troglofauna, are divided into three groups based on their life history - stygophiles, stygoxenes, and stygobites.<ref name=Lopes>{{cite journal |url=https://books.google.com/books?id=hfKdTbC55PUC |journal=Hydrobiologia |title=Copepoda: developments in ecology, biology and systematics: proceedings of the Seventh international conference on Copepoda, held in Curitiba |publisher=Springer |author=Rubens M. Lopes, Janet Warner Reid, Carlos Eduardo Falavigna Da Rocha |year=1999 |volume=453/454|pages=576|isbn=9780792370482 }}</ref>

=== Troglofauna ===
{{Main article|Troglofauna}}
[[File:A live individual of Zospeum tholussum.jpg|thumb|The microscopic cave snail ''[[Zospeum tholussum|Zospeum&nbsp;tholussum]]'', found at depths of {{convert|743|to|1392|m|ft|abbr=on}} in the [[Lukina jama|Lukina Jama–Trojama]] cave system of [[Croatia]], is completely blind with a translucent shell]]
Troglofauna are small [[cave]]-dwelling [[animal]]s that have [[adaptation|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 is associated with caves and spaces above the water table and stygofauna with water. Troglofaunal species include [[spider]]s, [[insect]]s, [[myriapods]] and others. Some troglofauna lives permanently underground and cannot survive outside the cave environment. Troglofauna adaptations and characteristics include a heightened sense of hearing, touch and smell.<ref name="Chapman">{{cite journal |author=Phil Chapman |title=The Origins of Troglobites |journal=Proceedings of the University of Bristol Spelæological Society |year=1982 |volume=16 |issue=2 |pages=133–141 |url=https://www.ubss.org.uk/resources/proceedings/vol16/UBSS_Proc_16_2_133-141.pdf }}</ref> 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 [[insect wing|wings]] and longer [[appendage]]s.

=== Xenofauna ===
{{Main article|Extraterrestrial life}}
''Xenofauna'', [[Drake equation|theoretically]], are [[Extraterrestrial life|alien]] organisms that can be described as [[Animal|animal analogues]]. While no alien life forms, animal-like or otherwise, are known definitively, the concept of alien life remains a subject of great interest in fields like [[astronomy]], [[astrobiology]], [[biochemistry]], [[evolutionary biology]], [[science fiction]], and [[philosophy]].

=== Other ===
[[File:Fauna.jpg|thumb|center|upright=3.2|Examples of fauna in [[Olleros de Tera]] ([[Spain]])]]

Other terms include ''[[avifauna]]'', which means "[[bird]] fauna" and ''piscifauna'' (or ''[[ichthyofauna]]''), which means "[[fish]] fauna".

== Treatises ==

=== Classic faunas ===
* [[Carl Linnaeus|Linnaeus, Carolus]]. ''Fauna Suecica''. 1746

== See also ==
{{Portal|Environment|Ecology|Earth sciences}}
{{Div col|colwidth=30em}}
* [[Biodiversity]]
* [[Biome]]
* [[Ecology]]
* [[Ecosystem]]
* [[Environmental movement]]
* [[Fauna and Flora Preservation Society]]
* [[Gene pool]]
* [[Genetic erosion]]
* [[Genetic pollution]]
* [[Natural environment]]
* [[Soil zoology]]
{{div col end}}

== References ==
{{Reflist}}

==External links==
{{Wiktionary|fauna}}
*[https://doi.org/10.1023%2FA%3A1008887817883 "Biodiversity of Collembola and their functional role in the ecosystem"] (by Josef Rusek; September 1998)

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