Editing Clownfish (section)

==Behaviour and ecology==
[[File:Clownfish in anemone off Vanuatu.ogg|thumb|right|Video of a [[cinnamon clownfish|A. melanopus]] swimming around an anemone]]
===Feeding===
Clownfish are [[omnivorous]], and mostly feed on [[plankton]]ic food such as [[copepod]]s and larval [[tunicate]]s. [[Algae]] is also an important food source and make up much of the diet of ''A. perideraion''. Clownfish will also feed on the waste dischanged by the anemone.{{sfn|Allen|1975b|pp=180, 184–189}}{{sfn|Fautin|Allen|1992|p=132}} Feeding takes up most of a clownfish's acivity; around 90 percent in dominant ''A. chrysopterus'' specifically. Where predators are less common, clownfish may forage as far as {{convert|20|m2|abbr=on}} of ocean floor away from their anemone. Otherwise they are restricted to feeding in the water column above their host.{{sfn|Allen|1975b|p=202}} The dominant pair in a clownfish group feed further from the anemone than the smaller subordinates.{{sfn|Fautin|Allen|1992|p=132}}

===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>

===Social structure===
[[File:Anemonefish komodo.jpg|thumb|right|Group of ''[[Amphiprion perideraion|A.  perideraion]]'', including the dominant pair and non-breeding individuals]]
A group of clownfish occupying an anemone usually consists of a breeding female and male along with some non-breeding individuals.<ref name=Beldade130/> [[Dominance hierarchy|Dominance]] in clownfish groups is based on size, with the female being the largest and most dominant, followed by the male and then the largest non-breeder and so on. An individual is 20 percent larger than its direct subordinate.<ref name=Beldade130/><ref name=Buston2004/> In ''A. percula'', the number of non-breeders ranges from zero to four, with group size depending on anemone size,<ref name=Buston2003>{{cite journal|last1=Buston|first1=P|year=2003|title=Forcible eviction and prevention of recruitment in the clown anemonefish|journal=Behavioral Ecology|volume=14|issue=4|pages=576–582|doi=10.1093/beheco/arg036}}</ref> as well as the size of the female as larger females allow for more members without unbalancing the size ratio between them.<ref>{{cite journal|last1=Buston|first1=P. M.|last2=Cant|first2=M. A.|year=2006|title=A new perspective on size hierarchies in nature: patterns, causes, and consequences|journal=Oecologia|volume=149|issue=2|pages=362–372|doi=10.1007/s00442-006-0442-z}}</ref> Members of a group are unrelated.<ref>{{cite journal|last1=Buston|first1=P. M.|last2=Bogdanowicz|first2=S. M.|last3=Wong|first3=A|last4=Harrison|first4=R. G.|year=2007|title=Are clownfish groups composed of close relatives? An analysis of microsatellite DNA variation in ''Amphiprion percula''|journal=Molecular Ecology|volume=16|issue=17|pages=3671–3678|doi=10.1111/j.1365-294X.2007.03421.x}}</ref>

As [[Sequential hermaphroditism|protandrous sequential hermaphrodite]]s, the male clownfish changes into a female when the previous one is lost, while the largest non-breeder becomes a male and the others rise in rank.<ref name=Beldade130>Beldade, R.; Bernardi, G.; Mills, S. C. "Anemonefish Behavior and Reproduction" in {{harvnb|Laudet|Ravasi|2023}} pp. 130</ref><ref name=Buston2004/> New fish that join the group rank at the bottom.<ref name=Buston2004>{{cite journal|last1=Buston|first1=P. M.|year=2004|title=Territory inheritance in clownfish|journal=Proceedings of the Royal Society B: Biological Science|volume=271|pages=S252–S254|doi=10.1098/rsbl.2003.0156}}</ref> Non-breeders are forced to wait for their time to become breeders, since nearby anemones are occupied and they are too small to challenge the dominants.<ref>{{cite journal|last1=Branconi|first1=R|last2=Barbasch|first2=T. A.|last3=Francis|first3=R. K.|last4=Srinivasan|first4=M|last5=Jones|first5=G. P.|last6=Buston|first6=P. M.|year=2020|title=Ecological and social constraints combine to promote evolution of non-breeding strategies in clownfish|journal=Communications Biology|volume=3|page=649|doi=10.1038/s42003-020-01380-8}}</ref> The dominant pair controls membership of the group and will drive away individuals when the anemone gets too full,<ref name=Buston2003/> particularly those that are close to them in size. Thus newcomers must remain smaller than their immediate superior to avoid getting evicted.<ref name=Buston2004/> Clownfish maintain their dominance hierarchy via displays, sound production and chasing. Sounds produced by clownfish include "clicks", "grunts", "pops" and "chirps". Dominants will chase their subordinates while producing a sound consisting of one or more long pulses. The subordinate submits to by emitting a sound with quicker pulses while shaking their heads.<ref>{{cite journal|last1=Colleye|first1=O|last2=Parmentier|first2=E|year=2012|title=Overview on the diversity of sounds produced by clownfishes (Pomacentridae): importance of acoustic signals in their peculiar way of life|journal=PLoS ONE|volume=7|issue=11|page=e49179|doi=10.1371/journal.pone.0049179|doi-access=free}}</ref> Clownfish appear to produce sounds via the jaws, which is amplified by the swim bladder.<ref>Parmentier, E.; Lecchini, D. "Sound Communication" in {{harvnb|Laudet|Ravasi|2023}} p. 100</ref><ref>{{cite journal|last1=Parmentier|first1=E|last2=Colleye|first2=O|last3=Fine|first3=M. L.|last4=Frédérich|first4=B|last5=Vandewalle|first5=P|last6=Herrel|first6=A|year=2007|title=Sound production in the clownfish ''Amphiprion clarkii''|journal=Science|volume=316|issue=5827|page=1006|doi=10.1126/science.1139753}}</ref>

One study of captive ''A. ocellaris'' found that the dominant pair are the most territorial while non-breeders are much less so. Both the male and female direct their aggression against intruders of the same sex, though resident males are more likely display than attack. Similarly non-breeding intruders are more likely to be simply intimidated.<ref>{{cite journal|last1=Iwata|first1=E|last2=Manbo|first2=J|year=2013|title=Territorial behaviour reflects sexual status in groups of false clown anemonefish (''Amphiprion ocellaris'') under laboratory conditions|journal=acta ethologica|volume=16|pages=97–103|doi=10.1007/s10211-012-0142-0}}</ref> Another study of the same species found they showed more aggression towards fish that have three vertical bars followed by those with two, then one and none, suggesting that it recognises and sees members of their species as their main competition for anemones.<ref name=Hayashi2024>{{cite journal|last1=Hayashi|first1=K|last2=Locke|first2=N. J. M.|last3=Laudet|first3=V|year=2024|title=Counting Nemo: anemonefish ''Amphiprion ocellaris'' identify species by number of white bars|journal=Journal of Experimental Biology|volume=227|issue=2|page=jeb246357|doi=10.1242/jeb.246357}}</ref> Conversely, ''A clarkii'' was observed to attack individuals of other species more than those of its own.<ref>{{cite journal|last=Hattori|first=A|year=2022|title=Small and large anemonefishes can coexist using the same patchy resources on a coral reef, before habitat destruction|journal=Journal of Animal Ecology|volume=71|issue=5|pages=824–831|doi=10.1046/j.1365-2656.2002.00649.x}}</ref>

<gallery mode="packed" heights="150px">
File:Amphiprion frenatus aggressive sounds - journal.pone.0049179.s001.ogv|''A. clarkii'' dominant chasing subordinate while producing aggressive sounds
File:Amphiprion frenatus submissive sounds - journal.pone.0049179.s002.ogv|''A. frenatus'' subordinate head-shaking while producing submissive sounds
</gallery>

===Reproduction and lifecycle===
Clownfish breed year-round in tropical waters while in more temperate waters, like those around Japan, breeding occurs mostly in spring and summer. Only the dominant female and male reproduce which mostly occurs during a [[full moon]]. In the days leading up to spawning, the pair perform courtship rituals which involve the male chasing and nibbling the female as well as erecting his dorsal pelvic and anal fins while staying motionless in front or alongside her. Both the female and male then prepare a nest by cleaning up a nearby rock. Here the female will deposit eggs for the male to [[External fertilization|fertilise]]. Clownfish lay up to a thousand eggs, which are conical in shape, {{convert|3|–|4|mm|abbr=on}} long and stick to the rocky substrate by bundles of short fibres.{{sfn|Fautin|Allen|1992|pp=126–129}}<ref name=Beldade132>Beldade, R.; Bernardi, G.; Mills, S. C. "Anemonefish Behavior and Reproduction" in {{harvnb|Laudet|Ravasi|2023}} p. 132</ref> The male tends to the fertilised eggs, cleaning and guarding them as well as fanning them with his pectoral fins.{{sfn|Fautin|Allen|1992|p=129}} 

Incubation lasts six to seven days.{{sfn|Fautin|Allen|1992|p=129}} The eggs start out bright orange and progressively darken, and the eyes of the embryos develop and become visible. The fish break out of their capsules during nighttime.<ref name=Beldade132/> After hatching, clownfish enter the larval and [[pelagic]] stage of their development. This stage lasts up to 12 days which is shorter than that of other damselfishes can last for 70 days.{{sfn|Fautin|Allen|1992|p=130}}<ref name=Roux2019>{{cite journal|last1=Roux|first1=N|last2=Salis|first2=P|last3=Lambert|first3=A|last4=Logeux|first4=V|last5=Soulat|first5=O|last6=Romans|first6=P|last7=Frédérich|first7=B|last8=Lecchini|first8=D|last9=Laudet|first9=V|year=2019|title=Staging and normal table of postembryonic development of the clownfish (''Amphiprion ocellaris'')|journal=Development Dynamtics|volume=248|issue=7|pages=545–568|doi=10.1002/dvdy.46}}</ref> Larval clownfish are initially transparent, expect for the eyes, yolk-sac and some pigment spots.{{sfn|Fautin|Allen|1992|p=130}} Over time they begin to [[metamorphosis|metamorphosise]]; growing in size and developing their fins, sensory and internal organs, [[notochord]] flexion and colouration.<ref name=Roux2019/> Clownfish larvae can [[biological dispersal|disperse]] widely across open ocean; ''[[Amphiprion omanensis|A. omanesis]]'' has been recorded travelling over {{convert|400|km|abbr=on}} along ocean currents.<ref>{{cite journal|last1=Simpson|first1=S. D.|last2=Harrison|first2=S. D.|last3=Claereboudt|first3=M. R.|last4=Planes|first4=S|year=2014|title=Long-distance dispersal via ocean currents connects Omani clownfish populations throughout entire species range|journal=PLoS ONE|volume=9|issue=9|page=e107610|doi=10.1371/journal.pone.0107610|doi-access=free}}</ref> 

As they enter the juvenile stage, clownfish begin settle to the ocean floor and find an anemone host,<ref name=Roux2019/> while transitioning to a more [[Diurnality|diurnal]] lifestyle.<ref>{{cite journal|last1=Schalm|first1=G|last2=Bruns|first2=K|last3=Drachenberg|first3=N|last4=Geyer|first4=N|last5=Foulkes|first5=N. S.|last6=Bertolucci|first6=C|last7=Gerlach|first7=G|year=2021|title=Finding Nemo’s clock reveals switch from nocturnal to diurnal activity|journal=Scientific Reports|volume=11|page=6801|doi=10.1038/s41598-021-86244-9}}</ref> Juveniles continue to grow and develop their adult colouration,<ref name=Roux2019/><ref name=whitebar/> but cannot produce [[gamete]]s until they ascend to dominance within a group.<ref name=Roux2019/> The dominant male's gonads produce sperm but also possess dormant ovarian cells. When transitioning into a female, the gonads switch to producing ovaries.{{sfn|Fautin|Allen|1992|p=131}} The transition from male to female starts with an increases in body size and feminisation of the brain, followed by gonadal changes and then behaviour changes. The process can last over four months.<ref>Casas, L.; Parker, C. G.; Rhodes, J. S. "Sex Change from Male to Female: Active Feminization of the Brain, Behavior, and Gonads in Anemonefish" in {{harvnb|Laudet|Ravasi|2023}} p. 119</ref> Clownfish can live for over 20 years.<ref>Mutalipassi, M.; Tozzini, E. T.; Cellerino, A. "Age and Longevity" in {{harvnb|Laudet|Ravasi|2023}} pp. 79–80</ref> ''A. percula'' is estimated to reach 30 years; twice as much as the average reef damselfish and six times that of a fish its size.<ref>{{cite journal|last1=Buston|first1=P. M.|last2=Garcia|first2=M. B.|year=2007|title=An extraordinary life span estimate for the clown anemonefish ''Amphiprion percula''|journal=Journal of Fish Biology|volume=70|issue=6|pages=1710–1719|doi=10.1111/j.1095-8649.2007.01445.x}}</ref> 

<gallery mode="packed" heights="150px">
File:Amphiprion ocellaris, puesta.jpg|''A. ocellaris'' male tending to eggs
File:Anemone Fish Eggs.jpg|Clownfish eggs closer to hatching
File:Clownfish growth.webp|Development of ''A. ocellaris'' (above) and ''A. frenatus''
</gallery>