Editing Cichlid (section)

===Mating===
Cichlids mate either [[Monogamy in animals|monogamously]] or [[Animal sexual behaviour#Polygamy|polygamously]].<ref name="Loiselle" /> The mating system of a given cichlid species is not consistently associated with its brooding system. For example, although most monogamous cichlids are not mouthbrooders, ''[[Chromidotilapia]]'', ''[[Gymnogeophagus]]'', ''[[Spathodus]]'', and ''[[Tanganicodus]]'' all include – or consist entirely of – monogamous mouthbrooders. In contrast, numerous open- or cave-spawning cichlids are polygamous; examples include many ''[[Apistogramma]]'', ''[[Lamprologus]]'', ''[[Nannacara]]'', and ''[[Pelvicachromis]]'' species.<ref name="Loiselle" /><ref name="martin">{{cite journal|author=Martin, E.|author2=M. Taborsky|year=1997|title=Alternative male mating acttics in a cichlid, ''Pelvicachromis pulcher'': a comparison of reproductive effort and success|journal=Behavioral Ecology and Sociobiology|volume=41|issue=5|pages=311–319|doi=10.1007/s002650050391|bibcode=1997BEcoS..41..311M |s2cid=27852520}}</ref>

Most adult male cichlids, specifically in the cichlid tribe Haplochromini, exhibit a unique pattern of oval-shaped color dots on their anal fins. These phenomena, known as egg spots, aid in the mouthbrooding mechanisms of cichlids. The egg spots consist of carotenoid-based pigment cells, which indicate a high cost to the organism, when considering that fish are not able to synthesize their own carotenoids.<ref name=pmid22028784>{{cite journal |last1=Egger |first1=Bernd |last2=Klaefiger |first2=Yuri |last3=Theis |first3=Anya |last4=Salzburger |first4=Walter |date=18 October 2011 |title=A sensory bias has triggered the evolution of egg-spots in cichlid fishes |journal=PLOS ONE |volume=6 |issue=10 |page=e25601 |doi=10.1371/journal.pone.0025601 |doi-access=free |pmid=22028784 |pmc=3196499 |bibcode=2011PLoSO...625601E}}</ref>

The mimicry of egg spots is used by males for the fertilization process. Mouthbrooding females lay eggs and immediately snatch them up with their mouths. Over millions of years, male cichlids have evolved egg spots to initiate the fertilization process more efficiently.<ref name=pmid25296686>{{cite journal |last1=Santos |first1=M. Emília |last2=Braasch |first2=Ingo |last3=Boileau |first3=Nicolas |last4=Meyer |first4=Britta S. |last5=Sauteur |first5=Loïc |last6=Böhne |first6=Astrid |last7=Belting |first7=Heinz-Georg |last8=Affolter |first8=Markus |last9=Salzburger |first9=Walter |display-authors=6 |date=9 October 2014 |title=The evolution of cichlid fish egg-spots is linked with a cis-regulatory change |journal=Nature Communications |volume=5 |page=5149 |doi=10.1038/ncomms6149 |pmid=25296686 |pmc=4208096 |bibcode=2014NatCo...5.5149S}}</ref> When the females are snatching up the eggs into their mouth, the males gyrate their anal fins, which illuminates the egg spots on his tail. Afterwards, the female, believing these are her eggs, places her mouth to the anal fin (specifically the genital papilla) of the male, which is when he discharges sperm into her mouth and fertilizes the eggs.<ref name=pmid22028784/>

The genuine color of egg spots is a yellow, red, or orange inner circle with a colorless ring surrounding the shape. Through phylogenetic analysis, using the mitochondrial ''ND2'' gene, the true egg spots are thought to have evolved in the common ancestor of the ''Astatoreochromis'' lineage and the modern ''Haplochrominis'' species. This ancestor was most likely riverine in origin, based on the most parsimonious representation of habitat type in the cichlid family.<ref name=pmid15723698>{{cite journal |last1=Salzburger |first1=Walter |last2=Mack |first2=Tanja |last3=Verheyen |first3=Erik |last4=Meyer |first4=Axel |date=1 January 2005 |title=Out of Tanganyika: Genesis, explosive speciation, key-innovations and phylogeography of the haplochromine cichlid fishes |journal=BMC Evolutionary Biology |volume=5 |pages=17 |doi=10.1186/1471-2148-5-17 |pmc=554777 |pmid=15723698 |doi-access=free }}</ref> The presence of egg spots in a turbid riverine environment would seem particularly beneficial and necessary for intraspecies communication.<ref name=pmid15723698/>

Two pigmentation genes are found to be associated with egg-spot patterning and color arrangement. These are ''fhl2-a'' and ''fhl2-b'', which are paralogs.<ref name=pmid25296686/> These genes aid in pattern formation and cell-fate determination in early embryonic development. The highest expression of these genes was temporally correlated with egg-spot formation. A short, interspersed, repetitive element was also seen to be associated with egg spots. Specifically, it was evident upstream of the transcriptional start site of ''fhl2'' in only ''Haplochrominis'' species with egg spots<ref name=pmid25296686/>