Editing Clownfish (section)

===Mutualism===
{{further information|Symbiosis|Mutualism (biology)}}
Clownfish have a [[Mutualism (biology)|mutualistic]] [[Symbiosis|symbiotic]] relationship with sea anemones.{{sfn|Allen|1975b|p=180}}<ref name=Colleye312>Colleye, O.; Iwata, E.; Parmentier, E. "Clownfishes" in {{harvnb|Frédérich|Parmentier|2016}} p. 312–313</ref> They acclimate themselves to their hosts by touching, nipping and fanning the tentacles over a period of minutes to days.<ref name=Hoepner201/> The main benefit of living among anemones is protection from predators by anemone's stinging tentacles. Straying clownfish retreat to the safety of the tentacles when they encounter a potential threat and they are always near their hosts, with smaller fish rarely leaving the [[Sea anemone#Anatomy|oral disc]].<ref name=Fautin1991/>{{sfn|Allen|1975b|p=180}} Clownfish may even swim into the [[coelenteron]] (gastrovascular cavity), though Gerald Allen observes this to be uncommon. Nighttime is spend resting deep among the tentacles.{{sfn|Allen|1975b|p=180}} A less important benefit for clownfish is nourishment from the discharged waste and parasites.<ref name=Fautin1991/>{{sfn|Allen|1975b|p=180}} 
[[File:Clark's Anemonefish (6997549061).jpg|thumb|right|''[[Amphiprion clarkii|A. clarkii]]'' with an ''[[Entacmaea quadricolor|E. quadricolor]]'' anemone, the species utilizes all ten anemone species which host clownfish]]
Anemones are less dependent on clownfish than the fish are of them; as evident as many individuals of host species lack clownfish.<ref name=Fautin1991/> Nevertheless, clownfish contribute to the survival of their hosts by guarding from anemone-eating fish such as the [[butterflyfish]] species ''[[Chaetodon lunula]]''.<ref name=Fautin1991/>{{sfn|Allen|1975b|p=183}} Other benefits they provide include the cleaning off of copepod parasites, increased oxygen flow via the rapid movements of the fish's fins and the attraction of more zooxanthellae by clownfish waste.<ref name=Colleye312/><ref>{{cite journal|last1=Szczebak|first1=J. T.|last2=Henry|first2=R. P.|last3=Al-Horani|first3=F. A.|last4=Chadwick|first4=N. E.|year=2013|title=Anemonefish oxygenate their anemone hosts at night|journal=Journal of Experimental Biology|volume=216|issue=6|pages=970–976|doi=10.1242/jeb.075648}}</ref> A 2005 study found that anemone grew and regenerated faster with clownfish them without, and attributed this to [[ammonium]] from clownfish waste.<ref name="D. Porat">{{cite journal |last1=Porat |first1=D. |last2=Chadwick-Furman |first2=N.E. |title=Effects of anemonefish on giant sea anemones: Ammonium uptake, zooxanthella content and tissue regeneration |journal=Marine and Freshwater Behaviour and Physiology |date=March 2005 |volume=38 |issue=1 |pages=43–51 |doi=10.1080/10236240500057929 |bibcode=2005MFBP...38...43P |s2cid=53051081 }}</ref>

A total of ten sea anemone species are used by clownfish as hosts: ''[[Radianthus malu]]'', ''[[Radianthus crispa|R. crispa]]'', ''[[Radianthus magnifica|R. magnifica]]'', ''[[Stichodactyla mertensii]]'', ''[[Stichodactyla haddoni|S. haddoni]]'', ''[[Stichodactyla gigantea|S. gigantea]]', [[Cryptodendrum adhaesivum]]'', ''[[Entacmaea quadricolor]]'', ''[[Heteractis aurora]]'' and ''[[Macrodactyla doreensis]]''. Some clownfish are [[Generalist and specialist species|generalist]] in their choice of hosts while others are more specialised. ''[[Clark's anemonefish|A. clarkii]]'' is the most generalised species and utilises all ten anemone species, while nine — ''[[Amphiprion frenatus|A. frenatus]]'', ''[[Amphiprion chagosensis|A. chagosensis]]'', ''[[Amphiprion pacificus|A. pacificus]]'', ''[[Amphiprion fuscocaudatus|A. fuscocaudatus]]'', ''[[Amphiprion latifasciatus|A. latifasciatus]]'', ''[[Amphiprion mccullochi|A. mccullochi]]'', ''[[Amphiprion nigripes|A. nigripes]]'', ''[[Amphiprion sebae|A. sebae]]'', and ''A. biaculeatus'' — use just one anemone species. Desirable traits in a host include long tentacles to hide among. In addition, certain anemones like ''H. aurora'' and ''E. quadricolor'' have tentacles with knob-like structures which provide more surface area for the fish to conceal itself. ''R. magnifica'' can provide extra protection when it pulls all its tentacles inside a soft body. The potency of venom is also a desirable trait; highly toxic anemone species tend to have smaller tentacles and so provide less shelter but more protection.<ref name=Hoepner198>Hoepner, C. M.; Fobert, E. K.; Abbott, C. A.; da Silva, K. B. "No Place Like Home: Can Omics Uncover the Secret behind the Sea Anemone and Anemonefish Symbiotic Relationship?" in {{harvnb|Laudet|Ravasi|2023}} pp. 198–200</ref>

Their ability to avoid being stung is attributed to their mucus coating.<ref name=Fautin1991/> There is evidence that clownfish mucus mimics the molecules or bacteria of anemone mucus and lacks  trigger for the anemone’s [[nematocyst]]s (stinging barbs). Mucus thickness may also play a role, but this is not clear.<ref name=Hoepner201>Hoepner, C. M.; Fobert, E. K.; Abbott, C. A.; da Silva, K. B. "No Place Like Home: Can Omics Uncover the Secret behind the Sea Anemone and Anemonefish Symbiotic Relationship? in {{harvnb|Laudet|Ravasi|2023}} pp. 201–204</ref> There is dispute over how much of the mucus is innate to the clownfish and how much is gained from the anemone during the acclimation period.<ref name=Fautin1991/> Nguyen and colleagues (2023) write "Whereas some anemone fish species seem to produce their own protective mucous coating, others may acquire mucus (or biomolecules within) from the sea anemone during an acclimation period".<ref>{{cite journal|last1=Nguyen|first1=H-T. T|last2=Zhao|first2=M|last3=Wang|first3=T|last4=Dang|first4=B. T.|last5=Geffen|first5=A. J.|last6=Cummins|first6=S. F.|year=2023|title=Sea anemone–anemone fish symbiosis: behavior and mucous protein profiling|journal=Journal of Fish Biology|volume=105|issue=2|pages=603–618|doi=10.1111/jfb.15772}}</ref> Roux and colleagues (2019) found evidence that clownfish exchange [[microbiota]] with their anemone hosts.<ref>{{cite journal|last1=Roux|first1=N|last2=Lami|first2=R|last3=Salis|first3=P|last4=Magré|first4=K|last5=Romans|first5=P|last6=Masanet|first6=P|last7=Lecchini|first7=D|last8=Laudet|first8=V|year=2019|title=Sea anemone and clownfish microbiota diversity and variation during the initial steps of symbiosis|journal=Scientific Reports|volume=9|page=19491|doi=10.1038/s41598-019-55756-w}}</ref>