Editing Cichlid (section)

=== Aggression ===
Aggressive behavior in cichlids is ritualized and consists of multiple displays used to seek confrontation while being involved in evaluation of competitors,<ref name=":0">{{Cite web|url=http://news.stanford.edu/news/2007/january31/fishsr-013007.html|title=Study: Cichlids can determine their social rank by observation|last=Shwartz|first=Mark|date=25 January 2007|publisher=Stanford University|access-date=11 December 2018}}</ref> coinciding with temporal proximity to mating. Displays of [[ritualized aggression]] in cichlids include a remarkably rapid change in coloration, during which a successfully dominant<ref name=":0" /> territorial male assumes a more vivid and brighter coloration, while a subordinate or "nonterritorial" male assumes a dull-pale coloration.<ref>{{cite journal |last1=Chen |first1=Chun-Chun |last2=Fernald |first2=Russell D. |title=Visual Information Alone Changes Behavior and Physiology during Social Interactions in a Cichlid Fish (Astatotilapia burtoni) |journal=PLOS ONE |date=25 May 2011 |volume=6 |issue=5 |pages=e20313 |doi=10.1371/journal.pone.0020313 |pmid=21633515 |pmc=3102105 |bibcode=2011PLoSO...620313C |doi-access=free }}</ref> In addition to color displays, cichlids employ their [[lateral line]]s to sense movements of water around their opponents to evaluate the competing male for physical traits/fitness.<ref>{{Cite journal|last=Knight|first=Kathryn|date=1 October 2015|title=Fighting cichlids size up opposition with lateral line|journal=Journal of Experimental Biology|volume=218|issue=20|pages=3161|doi=10.1242/jeb.132563 |doi-access=free|bibcode=2015JExpB.218R3161K }}</ref> Male cichlids are very territorial due to the pressure of reproduction, and establish their territory and [[social status]] by physically driving out<ref name=":1">{{Cite journal|last=Fernald|first=Russell D.|date=1 January 2017|title=Cognitive skills and the evolution of social systems|journal=Journal of Experimental Biology|volume=220|issue=1|pages=103–113|doi=10.1242/jeb.142430 |pmid=28057833|pmc=5278620|bibcode=2017JExpB.220..103F }}</ref> challenging males (novel intruders)<ref>{{Cite journal|last1=Fernald|first1=Russell D.|last2=Kent|first2=Kai R.|last3=Hilliard|first3=Austin T.|last4=Becker|first4=Lisa|last5=Alcazar|first5=Rosa M.|date=15 August 2016|title=Two types of dominant male cichlid fish: behavioral and hormonal characteristics|journal=Biology Open|volume=5|issue=8|pages=1061–1071|doi=10.1242/bio.017640 |pmid=27432479|pmc=5004607}}</ref> through lateral displays (parallel orientation, uncovering gills),<ref>{{Cite journal|last1=Arnott|first1=Gareth|last2=Ashton|first2=Charlotte|last3=Elwood|first3=Robert W.|date=23 October 2011|title=Lateralization of lateral displays in convict cichlids|journal=Biology Letters|volume=7|issue=5|pages=683–685|doi=10.1098/rsbl.2011.0328 |pmc=3169077|pmid=21508024}}</ref> biting, or mouth fights (head-on collisions of open mouths, measuring jaw sizes, and biting each other's jaws). The cichlid social [[dichotomy]] is composed of a single dominant with multiple subordinates, where the physical aggression of males becomes a contest for resources<ref name=":1" /> (mates, territory, food). Female cichlids prefer to mate with a successfully [[Alpha (ethology)|alpha]] male with vivid coloration, whose territory has food readily available.