{{Short description|Species of fish}} {{Speciesbox | image = Yellotaildamsel.jpg | image_caption = Adult | image2 = Microspathodon chrysurus, West End, Honduras imported from iNaturalist photo 65139843 (cropped).jpg | image2_caption = Juvenile | status = LC | status_system = IUCN3.1 | status_ref = <ref name = IUCN>{{cite iucn | author1 = Rocha, L.A. | author2 = Myers, R. | name-list-style = amp | year= 2015 | title = ''Microspathodon chrysurus'' | article-number = e.T188617A1902927 | doi = 10.2305/IUCN.UK.2015-4.RLTS.T188617A1902927.en | access-date=28 November 2023}}</ref> | taxon = Microspathodon chrysurus | authority = (Cuvier, 1830) | synonyms = {{species list |Glyphidodon rudis |Poey, 1860 |Glyphisodon chrysurus |Cuvier, 1830 |Pomacentrus denegatus |Poey, 1860 |Pomacentrus niveatus |Poey, 1876}} | synonyms_ref = <ref name=worms>{{cite WoRMS |author= Bailly, Nicolas|year= 2008|title= ''Microspathodon chrysurus'' (Cuvier, 1830)|id= 281571 |access-date=28 November 2023}}</ref> }}
The '''yellowtail damselfish''' (''Microspathodon chrysurus'') is a species of damselfish native to tropical areas such as the Caribbean coast of Panama. Damselfish are abundant in coral reef environments. The International Union for Conservation of Nature lists this fish as being of "least concern". The species is exploited on a minor scale, for fisheries and the aquarium trade. It may be threatened by the invasive lionfish.
Adult and young adult damselfish differ significantly in terms of body color. The difference was so stark that researchers believed the adult and young adult forms were two distinct species.<ref>{{Cite book|title=Enumeratio piscium Cubensium / por Don Felipe Poesy.|last=Poey|first=Felipe|date=1875|publisher=Imprenta de T. Fortanet|location=Madrid|doi = 10.5962/bhl.title.12630|url=https://www.biodiversitylibrary.org/item/46131 }}</ref> Adults are brown with a yellow caudal fin. Young adults are violet with blue spots in their back and transparent caudal fins.
== Reproduction == The spawning cycle of the yellowtail damselfish starts at sunrise and lasts approximately 1 hour after male damselfish have prepared nests on dead coral surfaces. Their eggs are demersal, adhering to the substrate where males guard and aerate them.<ref>{{Citation|last1=Pauly|first1=Daniel|title=Fisheries Management|date=2014-09-15|work=eLS|publisher=John Wiley & Sons, Ltd|isbn=978-0-470-01590-2|last2=Froese|first2=Rainer|doi=10.1002/9780470015902.a0003252.pub3}}</ref> Hatching occurs the morning of the 6th day of incubation. Reproductive activity is highest during the lunar period between full and new moon. At those points in the lunar cycle, the gravitational pull of the sun and the moon are very high resulting in spring tides.<ref>{{Cite journal|last=Pressley|first=Peter H.|date=April 1980|title=Lunar periodicity in the spawning of yellowtail damselfish,Microspathodon chrysurus|journal=Environmental Biology of Fishes|volume=5|issue=2|pages=155–159|doi=10.1007/bf02391622|bibcode=1980EnvBF...5..155P |issn=0378-1909}}</ref>
== Feeding habits == In regards to feeding habits, adults typically graze on algae while juveniles are carnivorous.<ref>{{Cite book|title=Systematic catalogue of the fishes of Tortugas, Florids with observations on color, habits, and local distribution by William H. Longley ... Edited and completed by Samuel F. Hildebrand ...|last=Longley|first=William Harding|date=1941|publisher=[s.n.]|location=Washington, D.C.|doi = 10.5962/bhl.title.6221}}</ref> ''M. chrysurus'' is omnivorous with a gradual change in feeding habits throughout development. This change in diet is related to the distribution of adult and young adult damselfish. Gut content analysis of yellowtail damselfish shows a change is food ingested from young adulthood to adulthood. Young adults primarily feed on animal-like nematocysts and zooxanthellae. Adults tend to tend to be more selective in their feeding habits, eating blue-green algae called cyanophytes. However, if there is an abundance of another food source available those are likely to be ingested by the species.<ref>{{Cite journal|last=Rasa|first=O. Anne E.|date=1971|title=The Causal Factors and Function of Yawning' in Microspathodon Chrysurus (Pisces: Pomacentridae)|journal=Behaviour|volume=39|issue=1|pages=39–57|doi=10.1163/156853971x00168|pmid=4325535 |s2cid=18102258 |issn=0005-7959|url=http://pdfs.semanticscholar.org/40cc/b63feb16d459b5d249394153b600a2c39583.pdf|archive-url=https://web.archive.org/web/20190222164056/http://pdfs.semanticscholar.org/40cc/b63feb16d459b5d249394153b600a2c39583.pdf|archive-date=2019-02-22}}</ref>
=== Clutch cannibalism === Clutch cannibalism occurs when a parent consumes its brood. Total clutch cannibalism by parental males has been observed in yellowtail damselfish directly and by analysis of gut contents. There are several working hypotheses as to why this behavior has been conserved. It is hypothesized that the decision to stop providing care could be to reallocate time and energy to attract more mates and thus increase lifetime reproductive success. Another possible reason is to increase growth rate or survival of parental damselfish in poorer condition.
The patterns of clutch loss are related to size of the brood. There is a significant tendency for smaller clutches to disappear. Most of the clutches that disappear in ''M. chrysurus'' are young, first day clutches. Researchers have not found this pattern of loss to be attributed to reproductive activity.<ref>{{Cite journal|last=Petersen|first=Christopher W.|date=March 1990|title=The occurrence and dynamics of clutch loss and filial cannibalism in two Caribbean damselfishes|journal=Journal of Experimental Marine Biology and Ecology|volume=135|issue=2|pages=117–133|doi=10.1016/0022-0981(90)90011-z|bibcode=1990JEMBE.135..117P |issn=0022-0981}}</ref>
== Cohabitation and interspecies competition == There is interspecific overlap of feeding areas of ''M. chrysurus'' and two other damselfish species—''Stegastes dorsopunicans'' and ''Stegastes planifrons''. All three cohabitants consume the same benthic microalgae and have the same feeding cycles. In terms of defending the feeding grounds from intruders, studies have shown that ''M. chrysurus'' is less competent than Stegastes spp. at inhibiting intruders. However, yellowtail damselfish have a competitive advantage because of their size. ''M. chrysurus'' are aggressive toward their cohabitants, using their size-based dominance to obtain food.<ref>{{Cite journal|last=Robertson|first=D. Ross|date=August 1984|title=Cohabitation of Competing Territorial Damselfishes on a Caribbean Coral Reef|journal=Ecology|volume=65|issue=4|pages=1121–1135|doi=10.2307/1938320|issn=0012-9658|jstor=1938320|bibcode=1984Ecol...65.1121R }}</ref>
==Gallery== <gallery mode="packed"> File:Elkhorn Coral with a Yellowtail Damselfish in the Caribbean Sea in Curaçao.jpg|Elkhorn coral with a Yellowtail Damselfish in the Caribbean Sea in Curaçao File:Yellowtail damselfish Microspathodon chrysurus (4657125482).jpg File:Damselfish-Microspathodon chrysurus.jpg File:Damselfish MicrospathodonChrysurus.jpg File:Yellowtail Damselfish2.jpg </gallery>
==References== {{Reflist}}
==External links== * {{Commons category-inline}} * {{SealifePhotos|281571}}
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chrysurus Category:Fish of the Caribbean Category:Fish described in 1830 Category:Taxa named by Georges Cuvier