Editing Common carp (section)

==Mirror carp==
[[File:Rectangle the mirror carp at 12lb 8oz.jpg|thumb|A {{cvt|12|lb|adj=on}} mirror carp]]
'''Mirror carp''', regionally known as '''Israeli carp''',{{refn|group="note"|This [[wikt:vernacular|vernacular]] name most likely owes to the [[Israel]]i development of a mirror carp strain called "Dor-70"<ref name="kirpitchnikov" />{{rp|75}} that has been widely exported, although these fish, introduced to the United States in the 1950s, are distinguishable from other fish called mirror carp according to ''Fishes of Arkansas''.<ref>{{cite book |title=Fishes of Arkansas |last1=Robison |first1=Henry W. |last2=Buchanan |first2=Thomas M. |isbn=978-1682261033 |publisher=The University of Arkansas Press |location=Fayetteville |pages=144 |edition=2nd |year=2020}}</ref>}} are a type of domesticated [[fish]] commonly found in Europe but widely introduced or cultivated elsewhere. They are a variety of the common carp (''Cyprinus carpio'') developed through [[selective breeding]]. The name "mirror carp" originates from their scales' resemblance to mirrors.

===Genetics===
The most striking difference between mirror and common carp is the presence of large, mirror-like scales on the former. The mirror-scale phenotype is caused by a genetic [[mutation]] present at one of two scale trait [[locus (genetics)|loci]], denoted by their S and N [[allele]]s, respectively. The [[genotype]] that produces a mirror scale phenotype is "ssnn" (all recessive), while wild-type carp may have either SSnn or Ssnn genotype.<ref name="kirpitchnikov" />{{rp|13-14}} The "S" locus has been identified as containing the gene encoding [[fibroblast growth factor receptor]] Fgfr1A1, which was [[paralog|duplicated]] during the course of carp evolution and consequently does not typically produce lethal phenotypes when only one locus is mutated.<ref>{{cite journal |last1=Rohner |first1=Nicolas |last2=Bercsényi |first2=Miklós |last3=Orbán |first3=László |last4=Kolanczyk |first4=Maria E. |last5=Linke |first5=Dirk |last6=Brand |first6=Michael |last7=Nüsslein-Volhard |first7=Christiane |last8=Harris |first8=Matthew P. |title=Duplication of ''fgfr1'' Permits Fgf Signaling to Serve as a Target of Selection during Domestication |journal=Current Biology |volume=19 |issue=19 |date=2009 |pages=1642–1647 |doi=10.1016/j.cub.2009.07.065 |doi-access=free|pmid=19733072 |bibcode=2009CBio...19.1642R }}</ref> The "N" locus has not been identified,<ref name="casas">{{cite journal |title=Disappearing Scales in Carps: Re-Visiting Kirpichnikov's Model on the Genetics of Scale Pattern Formation |last1=Casas |first1=Laura |last2=Szűcs |first2=Réka |last3=Vij |first3=Shubha |last4=Goh |first4=Chin Heng |last5=Kathiresan |first5=Purushothaman |last6=Németh |first6=Sándor |last7=Jeney |first7=Zsigmond |last8=Bercsényi |first8=Miklós |last9=Orbán |first9=László |journal=PLOS ONE |date=2013 |volume=8 |issue=12 |pages=e83327 |id=e83327 |doi=10.1371/journal.pone.0083327 |doi-access=free|pmid=24386179 |pmc=3875451 |bibcode=2013PLoSO...883327C }}</ref> but is hypothesized to have bearing on the development of embryonic [[mesenchyme]].<ref name="kirpitchnikov">{{cite book |last=Kirpitchnikov |first=Valentin S. |editor-last1=Billard |editor-first1=R. |editor-last2=Repérant |editor-first2=J. |editor-last3=Rio |editor-first3=J.P. |editor-last4=Ward |editor-first4=R. |title=Genetics and Breeding of Common Carp |publisher=INRA |year=1999 |location=Paris |isbn=2-7380-0869-0}}</ref>{{rp|17-18}}

Contrary to popular belief, a leather carp is not always a mirror carp without scales. Similar to mirror carp, leather, or "nude" carp, are homozygous recessive at the "S" locus, but unlike mirror carp, true leather carp are heterozygous for a dominant mutant allele at the "N" locus (ssNn genotype).{{refn|group="note"|Homozygosity for the dominant "N" allele is lethal.<ref name="kirpitchnikov" />{{rp|13}}  Heterozygosity reduces viability.<ref name="kirpitchnikov" />{{rp|15}}}} Leather carp also have reduced numbers of red blood cells and slower growth rates than scaled carp.<ref name="kirpitchnikov" />{{rp|16-17}} Mirror carp from Hungarian and Asian stocks have been observed to have fewer [[pharyngeal teeth]] than scaled carp, while nude carp had fewer still.<ref name="casas" />

A population of mirror carp in [[Madagascar]] (there an [[invasive species]]) was found to have reverted to full scale cover after being introduced from France in the early twentieth century.<ref name="hubert">{{cite journal |last1=Hubert |first1=Jean-Noël |last2=Allal |first2=François |last3=Hervet |first3=Caroline |last4=Ravakarivelo |first4=Monique |last5=Jeney |first5=Zsigmond |last6=Vergnet |first6=Alain |last7=Guyomard |first7=René |last8=Vandeputte |first8=Marc |title=How could fully scaled carps appear in natural waters in Madagascar? |journal=Proceedings of the Royal Society B: Biological Sciences |year=2016 |volume=283 |issue=1837 |doi=10.1098/rspb.2016.0945 |doi-access=free |pmid=27559059 |id=20160945|pmc=5013790 }}</ref> The feral Malagasy carp still possessed large scales due to their mirror phenotype, but had increased scale coverage approaching that of wild-type carp.<ref name="hubert" /> Hubert et al. (2016) found that the recessive allele at the "S" locus was still [[fixed allele|fixed]] in the population.<ref name="hubert" /> They believe that the phenotypic reversion was due to compensation by [[quantitative trait]] loci as a result of a [[natural selection|selective disadvantage]] for partial scaling in the wild, perhaps related to an impairment in parasite resistance.<ref name="hubert" />