Editing Cichlid (section)

==Hybrids and selective breeding==
[[File:Red Texas.jpg|thumb|right|200px|The "red Texas cichlid" is not a [[Texas cichlid]] (''Herichthys cyanoguttatus'') but a cross-genus hybrid of ''[[Herichthys]]'' and ''[[Amphilophus]]'' parents.]]
Some cichlids readily [[Hybrid (biology)|hybrid]]ize with related species, both in the wild and under artificial conditions.<ref>{{cite journal |author1=Smith, P.F. |author2=Konings, A. |author3=Kornfield, I. |date=July 2003 |title=Hybrid origin of a cichlid population in Lake Malawi: Implications for genetic variation and species diversity |journal=[[Molecular Ecology]] |volume=12 |issue=9 |pages=2497–2504 |doi=10.1046/j.1365-294X.2003.01905.x |pmid=12919487 |bibcode=2003MolEc..12.2497S |s2cid=2829927 }}</ref> Other groups of fishes, such as European [[Cyprinidae|cyprinids]], also hybridize.<ref>{{cite journal |last1=Wood |first1=A.B. |last2=Jordan |first2=D. R. |title=Fertility of roach × bream hybrids, ''Rutilus rutilus'' (L.) × ''Abramis brama'' (L.), and their identification |journal=Journal of Fish Biology |date=March 1987 |volume=30 |issue=3 |pages=249–261 |doi=10.1111/j.1095-8649.1987.tb05750.x |bibcode=1987JFBio..30..249W }}</ref> Unusually, cichlid hybrids have been put to extensive commercial use, in particular for aquaculture and aquaria.<ref name="Chapman"/><ref>{{cite web |title=Frequently asked questions on parrot cichlids |author=Clarke, Matt |website=Practical Fishkeeping |url=http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=331 |access-date=20 October 2006 |archive-url=https://web.archive.org/web/20070926235443/http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=331 |archive-date=26 September 2007 |url-status=dead}}</ref> The hybrid red strain of [[tilapia]], for example, is often preferred in aquaculture for its rapid growth. Tilapia hybridization can produce all-male populations to control stock density or prevent reproduction in ponds.<ref name="Chapman"/>

===Aquarium hybrids===
The most common aquarium hybrid is perhaps the [[blood parrot cichlid]], which is a cross of several species, especially from species in the genus ''[[Amphilophus]]''. (There are many hypotheses, but the most likely is: ''[[Amphilophus labiatus]]'' × ''[[Vieja melanurus|Vieja synspillus]]'' {{citation needed|date=January 2019}} With a triangular-shaped mouth, an abnormal [[Vertebral column|spine]], and an occasionally missing [[caudal fin]] (known as the "love heart" [[parrot]] cichlid), the fish is controversial among aquarists. Some have called blood parrot cichlids "the Frankenstein monster of the fish world".<ref name="aquafriend">{{cite web|url=http://www.aquafriend.com/modules.php?op=modload&name=News&file=article&sid=66&mode=thread&order=0&thold=0 |title=It's The Frankenstein Monster of the Fish World: The Blood Parrot! |publisher=AquaFriend.com |date=27 October 2002 |access-date=5 December 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060516094604/http://www.aquafriend.com/modules.php?op=modload&name=News&file=article&sid=66&mode=thread&order=0&thold=0 |archive-date=16 May 2006}}</ref> Another notable hybrid, the [[flowerhorn cichlid]], was very popular in some parts of [[Asia]] from 2001 until late 2003, and is believed to bring good luck to its owner.<ref>{{cite news |author=Arnold, W. |date=1 July 2003 |title=Singapore's 'lucky' pet Luohan can outnumber people in homes |newspaper=[[International Herald Tribune]]}}</ref> The popularity of the flowerhorn cichlid declined in 2004.<ref>{{cite news |title=Crayfish the latest fad among pet lovers |newspaper=[[New Straits Times]] |place=Singapore, Malaysia |date=3 September 2004}}</ref> Owners released many specimens into the rivers and canals of [[Malaysia]] and [[Singapore]], where they threaten endemic communities.<ref>{{cite news |title=Flower horn: Joy in homes, a pest in rivers |newspaper=[[New Straits Times]] |place=Singapore, Malaysia |date=14 July 2004}}</ref>
[[File:Long finned oscar.jpg|right|thumb|200px|A [[Leucism|leucistic]] long-finned form of the oscar, ''A. ocellatus'']]
Numerous cichlid species have been [[selective breeding|selectively bred]] to develop ornamental aquarium strains. The most intensive programs have involved angelfish and discus, and many [[mutation]]s that affect both coloration and fins are known.<ref name=Loiselle/><ref>{{cite magazine |last=Norton |first=J. |year=1982 | title = Angelfish genetics |magazine=Freshwater and Marine Aquarium Magazine |volume=5 |page=4}}</ref><ref>{{cite journal |last1=Koh |first1=Tieh Ling |last2=Khoo |first2=Gideon |last3=Fan |first3=Li Qun |last4=Phang |first4=Violet Pan Eng |date=30 March 1999 |title=Genetic diversity among wild forms and cultivated varieties of Discus (''Symphysodon'' spp.) as revealed by random amplified polymorphic DNA (RAPD) fingerprinting |journal=Aquaculture |volume=173 |issue=1 |pages=485–497 |doi=10.1016/S0044-8486(98)00478-5 |bibcode=1999Aquac.173..485K }}</ref> Other cichlids have been bred for [[albino]], [[Leucism|leucistic]], and [[Xanthochromism|xanthistic]] [[pigment]] [[mutation]]s, including [[Oscar (fish)|oscars]], [[convict cichlid]] and ''[[Pelvicachromis pulcher]]''.<ref name=Loiselle/><ref name=baensch/> Both [[dominance (genetics)|dominant]] and [[dominance (genetics)|recessive]] pigment mutations have been observed.<ref name=Kornfield1991>{{cite book |author=Kornfield, I. |year=1991 |section=Genetics |title=Cichlid Fishes: Behaviour, ecology and evolution |editor=Keenleyside, M.H.A. |publisher=Chapman and Hall |place=London, UK |pages=109–115}}</ref> In [[convict cichlid]]s, for example, a leucistic coloration is recessively inherited,<ref>{{cite journal | last1 = Itzkovich | first1 = J. | last2 = Rothbard | first2 = S. | last3 = Hulata | first3 = G. | year = 1981 | title = Inheritance of pink body colouration in ''Cichlasoma nigrofasciatum'' Günther (Pisces, Cichlidae) | journal = Genetica | volume = 55 | pages = 15–16 | doi=10.1007/bf00133997| s2cid = 38828706 }}</ref> while in ''[[Oreochromis niloticus niloticus]]'', red coloration is caused by a dominant inherited mutation.<ref>{{cite journal | last1 = McAndrew | first1 = C.J. | last2 = Roubal | first2 = F.R. | last3 = Roberts | first3 = R.J. | last4 = Bullock | first4 = A.M. | last5 = McEwan | first5 = I.M. | year = 1988 | title = The genetics and history of red, blond, and associated color variants in ''Oreochromis niloticus'' | journal = Genetica | volume = 76 | issue = 2| pages = 127–137 | doi=10.1007/bf00058811| s2cid = 40666053 }}</ref>

This selective breeding may have [[unintended consequence]]s. For example, hybrid strains of ''[[Ram cichlid|Mikrogeophagus ramirezi]]'' have health and fertility problems.<ref name="dcichlids">
Linke H, Staeck L (1994) ''American cichlids I: Dwarf Cichlids. A handbook for their identification, care and breeding.'' Tetra Press. Germany. {{ISBN|1-56465-168-1}}</ref> Similarly, intentional [[inbreeding]] can cause physical abnormalities, such as the notched [[phenotype]] in [[Pterophyllum|angelfish]].<ref>{{cite journal |last1=Norton |first1=J |year=1994 |title=Notched – An Angelfish Deformity |journal=Freshwater and Marine Aquarium Magazine |volume=17 |issue=3 }}</ref>