cichlid

Cichlids span a wide range of body sizes, from species as small as {{convert|2.5|cm|in|0|abbr=on}} in length (e.g., female Neolamprologus multifasciatus) to much larger species approaching {{convert|1|m|ft|0|abbr=on}} in length (Boulengerochromis and Cichla). As a group, cichlids exhibit a similar diversity of body shapes, ranging from strongly laterally compressed species (such as Altolamprologus, Pterophyllum, and Symphysodon) to species that are cylindrical and highly elongated (such as Julidochromis, Teleogramma, Teleocichla, Crenicichla, and Gobiocichla).{{cite book |last = Loiselle |first = P.V. |year = 1994 |title = The Cichlid Aquarium |publisher = Tetra Press |isbn = 978-1-56465-146-4}} Generally, however, cichlids tend to be of medium size, ovate in shape, and slightly laterally compressed, and generally similar to the North American sunfishes in morphology, behavior, and ecology.{{cite book|author1=Helfman G. |author2=Collette B. |author3=Facey D. |title = The Diversity of Fishes|publisher = Blackwell Publishing, Inc.|pages = 256–257| year = 1997| isbn= 978-0-86542-256-8}}

Cichlids share a single key trait - the fusion of the lower pharyngeal bones into a single tooth-bearing structure. A complex set of muscles allows the upper and lower pharyngeal bones to be used as a second set of jaws for processing food, allowing a division of labor between the "true jaws" (mandibles) and the "pharyngeal jaws". Cichlids are efficient and often highly specialized feeders that capture and process a very wide variety of food items. This is assumed to be one reason why they are so diverse.

The following consensus taxonomy is based on the Catalog of Fishes (2025){{Cite web |last=Fricke |first=R. |last2=Eschmeyer |first2=W. N. |last3=Van der Laan |first3=R. |date=2025 |title=ESCHMEYER'S CATALOG OF FISHES: CLASSIFICATION |url=https://www.calacademy.org/eschmeyers-catalog-of-fishes-classification |access-date=2025-02-10 |website=California Academy of Sciences |language=en}}

• Family Cichlidae Bonaparte, 1835
• Subfamily Etroplinae Kullander, 1998 (Indian and Madagascan cichlids)
• Subfamily Ptychochrominae Sparks, 2004 (Malagasy cichlids)
• Subfamily Pseudocrenilabrinae Fowler, 1934 (African cichlids)
• Subfamily Cichlinae Bonaparte, 1835 (American cichlids)

In the past, cichlid taxonomy has varied depending on the author. Kullander (1998) recognized eight subfamilies of cichlids: the Astronotinae, Cichlasomatinae, Cichlinae, Etroplinae, Geophaginae, Heterochromidinae, Pseudocrenilabrinae, and Retroculinae.{{cite book|last=Kullander|first=S.O.|year=1998| chapter=A phylogeny and classification of the South American Cichlidae (Teleostei: Perciformes)|pages = 461–498 |editor = L.R. Malabarba |editor2=R.E. Reis |editor3=R.P. Vari |editor4=Z.M. Lucena |editor5=C.A.S. Lucena | title=Phylogeny and classification of neotropical fishes| location= Porto Alegre |publisher = EDIPUCRS | isbn = 978-85-7430-035-1 }} A ninth subfamily, the Ptychochrominae, was later recognized by Sparks and Smith.{{cite journal |author1=Sparks, J.S. |author2=Smith, W.L. | year = 2004 | title = Phylogeny and biogeography of cichlid fishes (Teleostei: Perciformes: Cichlidae) | journal = Cladistics | volume = 20 | pages = 501–517 | doi = 10.1111/j.1096-0031.2004.00038.x | issue = 6|pmid=34892958 |citeseerx=10.1.1.595.2118 |s2cid=36086310 }} Cichlid taxonomy is still debated, and classification of genera cannot yet be definitively given. A comprehensive system of assigning species to monophyletic genera is still lacking, and there is not complete agreement on what genera should be recognized in this family.{{cite book | title = Fishes of the World | last = Nelson | first = Joseph S. | publisher = John Wiley & Sons, Inc. | year = 2006 | isbn = 978-0-471-25031-9}}

As an example of the classification problems, Kullander{{Cite web |url=http://www2.nrm.se/ve/pisces/acara/cichphyl.shtml |title=Phylogeny of major groups of cichlids |access-date=10 June 2007 |archive-date=18 January 2012 |archive-url=https://web.archive.org/web/20120118213155/http://www2.nrm.se/ve/pisces/acara/cichphyl.shtml |url-status=dead }} placed the African genus Heterochromis phylogenetically within Neotropical cichlids, although later papers{{citation needed|date=December 2019}} concluded otherwise. Other problems center upon the identity of the putative common ancestor for the Lake Victoria superflock (many closely related species sharing a single habitat), and the ancestral lineages of Lake Tanganyikan cichlids.{{citation needed|date=December 2019}}

File:Aequidens pallidus MH-MCZArtwork ARC 209-201.jpg

Phylogeny derived from morphological characters shows differences at the genus level with phylogeny based on genetic loci.{{cite journal |last1=Streelman |first1=J.T. |last2=Zardoya |first2=R. |last3=Meyer |first3=A. |last4=Karl |first4=S. A. |date=1 July 1998 |title=Multilocus phylogeny of cichlid fishes (Pisces: Perciformes): evolutionary comparison of microsatellite and single-copy nuclear loci. |journal=Molecular Biology and Evolution |volume=15 |issue=7 |pages=798–808 |doi=10.1093/oxfordjournals.molbev.a025985 |pmid=10766579 |doi-access=free}} A consensus remains that the Cichlidae as a family are monophyletic.{{cite journal |last1=Salzburger |first1=Walter |last2=Meyer |first2=Axel |date=June 2004 |title=The species flocks of East African cichlid fishes: Recent advances in molecular phylogenetics and population genetics |journal=Naturwissenschaften |volume=91 |issue=6 |pages=277–90 |doi=10.1007/s00114-004-0528-6 |pmid=15241604 |bibcode=2004NW.....91..277S |s2cid=5816449 |url=http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-32995 }}

In cichlid taxonomy, dentition was formerly used as a classifying characteristic, but this was complicated because in many cichlids, tooth shapes change with age, due to wear, and cannot be relied upon. Genome sequencing and other technologies transformed cichlid taxonomy.

Alternatively, all cichlid species native to the New World, can be classified under the subfamily Cichlinae, while Etroplinae can classify all cichlid species native to the Old World.

The taxonomic placement of cichlids has long been disputed and variable, and has only recently been largely resolved. In the past, based on morphological characteristics, cichlids were classed in a suborder, the Labroidei, along with the wrasses (Labridae), in the order Perciformes.{{cite journal |author1=Stiassny, M.L.J. |author2=Jensen, J.S. |year=1987 |title=Labroid intrarelationships revisited: morphological complexity, key innovations, and the study of comparative diversity |journal=Bulletin of the Museum of Comparative Zoology |volume=151 |pages=269–319}} However, studies incorporating molecular phylogenetics have contradicted this grouping.{{cite journal |last1=Wainwright |first1=Peter C. |display-authors=etal |year=2012 |title=The evolution of pharyngognathy: A phylogenetic and functional appraisal of the pharyngeal jaw key innovation in labroid fishes and beyond |journal=Systematic Biology |volume=61 |issue=6 |pages=1001–1027 |doi=10.1093/sysbio/sys060 |pmid=22744773 |doi-access=free}}

More recent phylogenetic studies support the creation of a distinct order, the Cichliformes, to contain the cichlids and their close relatives, which are no longer thought to be closely related to wrasses. The closest living relative of cichlids has been found to be the marine convict blenny, and both families are classified in the 5th edition of Fishes of the World as the two families in the Cichliformes, part of the subseries Ovalentaria.{{cite book |author1=Nelson, J.S. |url=https://sites.google.com/site/fotw5th/ |title=Fishes of the World |author2=Grande, T.C. |author3=Wilson, M.V.H. |publisher=Wiley |year=2016 |isbn=978-1-118-34233-6 |edition=5th |pages=752 |access-date=5 November 2018 |archive-url=https://web.archive.org/web/20190408194051/https://sites.google.com/site/fotw5th/ |archive-date=8 April 2019 |url-status=dead}} The Catalog of Fishes adopts the same placement, although the leaffishes (which have a similar African and South American distribution) are now also placed in the Cichliformes.{{Cite web |last1=Fricke |first1=R. |last2=Eschmeyer |first2=W. N. |last3=Van der Laan |first3=R. |date=2025 |title=ESCHMEYER'S CATALOG OF FISHES: CLASSIFICATION |url=https://www.calacademy.org/eschmeyers-catalog-of-fishes-classification |access-date=2025-02-10 |website=California Academy of Sciences |language=en}} Although these interrelationships are now generally well-supported, other authors have interpreted these relationships in differing ways, such as instead placing the cichlids, leaffish, and convict blenny as the most basal members of an expanded Blenniiformes.{{Cite journal |last1=Near |first1=Thomas J. |last2=Thacker |first2=Christine E. |date=2024-04-18 |title=Phylogenetic Classification of Living and Fossil Ray-Finned Fishes (Actinopterygii) |url=https://bioone.org/journals/bulletin-of-the-peabody-museum-of-natural-history/volume-65/issue-1/014.065.0101/Phylogenetic-Classification-of-Living-and-Fossil-Ray-Finned-Fishes-Actinopterygii/10.3374/014.065.0101.full |journal=Bulletin of the Peabody Museum of Natural History |volume=65 |issue=1 |page=101 |doi=10.3374/014.065.0101 |bibcode=2024BPMNH..65..101N |issn=0079-032X}}

Modern cichlids have a disjunct distribution consisting of Africa (including Madagascar), the Neotropics (including Cuba and Hispaniola), the Levant, southern Iran, and the southern Indian subcontinent. This distribution has become the subject of much scientific dispute, with it being debated whether modern cichlid distribution is a consequence of the breakup of Gondwana (which would make cichlids a particularly ancient group dating to the Early Cretaceous), or if it is instead based on more recent oceanic dispersal by the cichlids (despite modern members of the group being largely restricted to freshwater).{{cite journal |last1=Chakrabarty |first1=Prosanta |date=June 2004 |title=Cichlid biogeography: comment and review |journal=Fish and Fisheries |volume=5 |issue=2 |pages=97–119 |bibcode=2004AqFF....5...97C |doi=10.1111/j.1467-2979.2004.00148.x |hdl-access=free |hdl=2027.42/72313}}

Proponents of the Gondwanan theory, which saw more support in the past, have noted that the cichlids display the precise sister relationships predicted by Gondwanan distribution: Africa-South America and India-Madagascar, and that with the exception of the species from Cuba, Hispaniola and Madagascar, cichlids have not reached any oceanic island. The dispersal hypothesis, in contrast, requires cichlids to have negotiated thousands of kilometers of open ocean between India and Madagascar without colonizing any other island, or for that matter, crossing the Mozambique Channel to Africa.

However, more recent studies incorporating phylogenetic evidence have found that the divergences within the cichlids are far too young for cichlids to have even been present for the breakup of Gondwana. Molecular clock estimates have placed the family's origin only to the Late Cretaceous period, and the divergences within the family to have occurred anywhere between the Late Cretaceous to the Eocene (depending on the study). This suggests that only dispersal can support modern cichlid distribution. However, the factors that may have allowed prehistoric cichlids to make migrations over entire oceans remains a mystery.{{Cite journal |last=Matschiner |first=Michael |date=2019-04-01 |title=Gondwanan vicariance or trans-Atlantic dispersal of cichlid fishes: a review of the molecular evidence |url=https://link.springer.com/article/10.1007/s10750-018-3686-9 |journal=Hydrobiologia |language=en |volume=832 |issue=1 |pages=9–37 |doi=10.1007/s10750-018-3686-9 |bibcode=2019HyBio.832....9M |issn=1573-5117|url-access=subscription }}{{Cite journal |last1=Matschiner |first1=Michael |last2=Böhne |first2=Astrid |last3=Ronco |first3=Fabrizia |last4=Salzburger |first4=Walter |date=2020-11-18 |title=The genomic timeline of cichlid fish diversification across continents |url=https://link.springer.com/article/10.1038/s41467-020-17827-9?fromPaywallRec=true |journal=Nature Communications |language=en |volume=11 |issue=1 |pages=5895 |doi=10.1038/s41467-020-17827-9 |bibcode=2020NatCo..11.5895M |issn=2041-1723|hdl=10852/83721 |hdl-access=free }}{{Cite journal |last1=Friedman |first1=Matt |last2=Keck |first2=Benjamin P. |last3=Dornburg |first3=Alex |last4=Eytan |first4=Ron I. |last5=Martin |first5=Christopher H. |last6=Hulsey |first6=C. Darrin |last7=Wainwright |first7=Peter C. |last8=Near |first8=Thomas J. |date=2013-11-07 |title=Molecular and fossil evidence place the origin of cichlid fishes long after Gondwanan rifting |journal=Proceedings of the Royal Society B: Biological Sciences |volume=280 |issue=1770 |pages=20131733 |doi=10.1098/rspb.2013.1733 |pmc=3779330 |pmid=24048155}} It is known that during the Paleogene, the Atlantic Ocean between South America and Africa was significantly narrower, and it has been suggested that either now-submerged islands or a large plume from the Congo River may have allowed for a shallower or less saline environment that was conducive for cichlids to disperse from Africa to South America. Under the dispersal hypothesis, it is generally accepted that Africa was the ancestral home for cichlids, from which they dispersed to attain their present distribution.

File:Warilochromis skeleton.png, a fossil cichlid from the Miocene of Kenya]]

The fossil record of cichlids is comprehensive, although it only starts in the Eocene, well after the family is thought to have undergone significant evolutionary diversification. Fossil cichlids appear in both South America and Africa at roughly the same time in the Eocene, with fossil cichlids known from the Early Eocene (48.6 mya)-aged Lumbrera Formation of Argentina,{{cite journal |last1=Malabarba |first1=Maria C. |last2=Malabarba |first2=Luiz R. |last3=López-Fernández |first3=Hernán |year=2014 |title=On the Eocene cichlids from the Lumbrera Formation: additions and implications for the Neotropical ichthyofauna |journal=Journal of Vertebrate Paleontology |volume=34 |issue=1 |pages=49–58 |bibcode=2014JVPal..34...49M |doi=10.1080/02724634.2013.830021}} as well as the Middle Eocene (46 mya)-aged Mahenge Formation of Tanzania,{{Cite journal |last=Murray |first=Alison M. |date=2001-01-19 |title=Eocene cichlid fishes from Tanzania, East Africa |url=https://www.tandfonline.com/doi/abs/10.1671/0272-4634(2000)020%5B0651:ECFFTE%5D2.0.CO;2 |journal=Journal of Vertebrate Paleontology |volume=20 |issue=4 |pages=651–664 |doi=10.1671/0272-4634(2000)020[0651:ECFFTE]2.0.CO;2 |issn=0272-4634|url-access=subscription }} suggesting that the divergence between Old and New World cichlids must have occurred prior to this point.

Several African fossil sites that contain cichlids (including the Eocene-aged Mahenge Formation of Tanzania and the Miocene-aged Ngorora Formation of Kenya){{Cite journal |last1=Penk |first1=Stefanie B. R. |last2=Altner |first2=Melanie |last3=F. Cerwenka |first3=Alexander |last4=Schliewen |first4=Ulrich K. |last5=Reichenbacher |first5=Bettina |date=2019-07-15 |title=New fossil cichlid from the middle Miocene of East Africa revealed as oldest known member of the Oreochromini |journal=Scientific Reports |language=en |volume=9 |issue=1 |pages=10198 |doi=10.1038/s41598-019-46392-5 |pmid=31308387 |pmc=6629881 |bibcode=2019NatSR...910198P |issn=2045-2322}} appear to represent former maars or rift lakes, and the fossil cichlids present in them appear to represent species flocks akin to those in the modern African rift lakes. This suggests that rapid diversification within enclosed ecosystems is a longstanding trait of cichlids.

Fossil remains also suggest that cichlids ranged further north in the geologic past, with the extinct tilapia Oreochromis lorenzoi being known from the Late Miocene of Italy.{{Cite journal |last1=Carnevale |first1=Giorgio |last2=Sorbini |first2=Chiara |last3=Landini |first3=Walter |date=2003-09-12 |title=Oreochromis lorenzoi, a new species of tilapiine cichlid from the late Miocene of central Italy |url=https://www.tandfonline.com/doi/abs/10.1671/1858 |journal=Journal of Vertebrate Paleontology |volume=23 |issue=3 |pages=508–516 |doi=10.1671/1858 |bibcode=2003JVPal..23..508C |issn=0272-4634|url-access=subscription }}

File:Tilapia mariae Australia.jpg, caught on a hook and line, in Australia: Originally from Africa, the species established feral populations in Australia.{{cite journal |last1=Koehn |first1=John D. |last2=MacKenzie |first2=Rachel F. |title=Priority management actions for alien freshwater fish species in Australia |journal=New Zealand Journal of Marine and Freshwater Research |date=August 2004 |volume=38 |issue=3 |pages=457–472 |doi=10.1080/00288330.2004.9517253 |doi-access=free |bibcode=2004NZJMF..38..457K |s2cid=83569110 }}]]

Cichlids are one of the largest vertebrate families in the world. They are most diverse in Africa and South America. Africa alone is host to at least an estimated 1,600 species. Central America and Mexico have about 120 species, as far north as the Rio Grande in South Texas. Madagascar has its own distinctive species (Katria, Oxylapia, Paratilapia, Paretroplus, Ptychochromis, and Ptychochromoides), only distantly related to those on the African mainland.{{FishBase family|family=Cichlidae|date=February 2012}}{{cite book|last=Boruchowitz|first=D. E.|year=2006| title=Guide to Cichlids| publisher=T.F.H. Publications| isbn=978-0-7938-0584-6}} Native cichlids are largely absent in Asia, except for 9 species in Israel, Lebanon, and Syria (Astatotilapia flaviijosephi, Oreochromis aureus, O. niloticus, Sarotherodon galilaeus, Coptodon zillii, and Tristramella spp.), two in Iran (Iranocichla), and three in India and Sri Lanka (Etroplus and Pseudetroplus). If disregarding Trinidad and Tobago (where the few native cichlids are members of genera that are widespread in the South American mainland), the three species from the genus Nandopsis are the only cichlids from the Antilles in the Caribbean, specifically Cuba and Hispaniola. Europe, Australia, Antarctica, and North America north of the Rio Grande drainage have no native cichlids, although in Florida, Hawaii, Japan, northern Australia, and elsewhere, feral populations of cichlids have become established as exotics.{{cite web|url=http://www.abc.net.au/farnorth/stories/s1313845.htm |title=Tilapia :: Far North Queensland |author=ABC Far North Queensland |website=Australian Broadcasting Corporation |access-date=19 April 2007 |archive-url=https://web.archive.org/web/20071017061120/http://abc.net.au/farnorth/stories/s1313845.htm |archive-date=17 October 2007 |url-status=dead}}{{cite web|url=http://filaman.uni-kiel.de/Summary/SpeciesSummary.php?id=3615|title=Archocentrus nigrofasciatus, Convict cichlid|editor=Froese, R.|editor2=D. Pauly|publisher=FishBase|access-date=29 March 2007|url-status=dead|archive-url=https://web.archive.org/web/20081201110621/http://filaman.uni-kiel.de/Summary/SpeciesSummary.php?id=3615|archive-date=1 December 2008}}{{cite book | author = Yamamoto, M.N.| author2 = Tagawa, A.W.| year = 2000| title = Hawai'i's native and exotic freshwater animals | publisher = Mutual Publishing | location = Honolulu, Hawaii | pages = 200}}{{cite book | author = Page, L.M. |author2 = Burr, B.M. | year = 1991| title = A field guide to freshwater fishes of North America north of Mexico| url = https://archive.org/details/fieldguidetofres00lawr | url-access = registration | publisher = Houghton Mifflin Company | location = Boston | pages = [https://archive.org/details/fieldguidetofres00lawr/page/432 432] | isbn = 978-0-395-35307-3}}{{cite web|author=University of Southern Mississippi/College of Marine Sciences/Gulf Coast Research Laboratory |title=Fact Sheet for Tilapia zilli (Gervais, 1848) |publisher=Gulf States Marine Fisheries Commission |date=3 August 2005 |url=http://nis.gsmfc.org/nis_factsheet2.php?toc_id=200 |access-date=10 February 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070818063521/http://nis.gsmfc.org/nis_factsheet2.php?toc_id=200 |archive-date=18 August 2007}}{{cite web | last1=Fuller | first1=Pam L. | first2=Leo G. |last2=Nico | title=Nonindigenous Fishes of Florida – With a Focus on South Florida | publisher=U.S. Department of the Interior, U.S. Geological Survey, Coastal and Marine Science Center | date=11 October 2002 | url=http://sofia.usgs.gov/sfrsf/rooms/species/invasive/focus/

|archive-url=https://web.archive.org/web/20030115221654/http://sofia.usgs.gov/sfrsf/rooms/species/invasive/focus/ |archive-date=2003-01-15 |url-status=dead}}

Although no longer present in Europe except as introductions, tilapias are known to have ranged as far north as Italy during the Miocene.

Although most cichlids are found at relatively shallow depths, several exceptions do exist. The deepest known occurrences are Trematocara at more than {{convert|300|m|ft|-2|abbr=on}} below the surface in Lake Tanganyika.Loiselle, Paul (1994). The Cichlid Aquarium, p. 304. Tetra Press, Germany. {{ISBN|978-1564651464}}. Others found in relatively deep waters include species such as Alticorpus macrocleithrum and Pallidochromis tokolosh down to {{convert|150|m|ft|-2|abbr=on}} below the surface in Lake Malawi,{{FishBase| genus = Alticorpus | species= macrocleithrum}}{{FishBase | genus = Pallidochromis | species= tokolosh }} and the whitish (nonpigmented) and blind Lamprologus lethops, which is believed to live as deep as {{convert|160|m|ft|abbr=on}} below the surface in the Congo River.Norlander, Britt (20 April 2009). [https://archive.today/20120708055831/http://findarticles.com/p/articles/mi_m1590/is_13_65/ai_n31583235/ Rough waters: one of the world's most turbulent rivers is home to a wide array of fish species. Now, large dams are threatening their future.] Science World

Cichlids are less commonly found in brackish and saltwater habitats, though many species tolerate brackish water for extended periods; Mayaheros urophthalmus, for example, is equally at home in freshwater marshes and mangrove swamps, and lives and breeds in saltwater environments such as the mangrove belts around barrier islands. Several species of Tilapia, Sarotherodon, and Oreochromis are euryhaline and can disperse along brackish coastlines between rivers. Only a few cichlids, however, inhabit primarily brackish or salt water, most notably Etroplus maculatus, Etroplus suratensis, and Sarotherodon melanotheron.{{cite book | author = Frank Schäfer | year = 2005 | title = Brackish-Water Fishes | publisher = Aqualog | isbn=978-3-936027-82-2}}{{page needed|date=November 2020}} The perhaps most extreme habitats for cichlids are the warm hypersaline lakes where the members of the genera Alcolapia and Danakilia are found. Lake Abaeded in Eritrea encompasses the entire distribution of D. dinicolai, and its temperature ranges from {{convert|29|to|45|C|F}}.{{cite journal |last1=Stiassny |first1=Melanie L. J. |last2=Marchi |first2=Giuseppe De |last3=Lamboj |first3=Anton |title=A new species of Danakilia (Teleostei, Cichlidae) from Lake Abaeded in the Danakil Depression of Eritrea (East Africa) |journal=Zootaxa |date=29 November 2010 |volume=2690 |issue=1 |pages=43–52 |doi=10.11646/zootaxa.2690.1.4 |s2cid=87705274 |url=https://pdfs.semanticscholar.org/51ff/077f4371672caa31f82b33e56ce59c63368b.pdf |archive-url=https://web.archive.org/web/20200212121742/https://pdfs.semanticscholar.org/51ff/077f4371672caa31f82b33e56ce59c63368b.pdf |url-status=dead |archive-date=12 February 2020 }} Although the vast majority of Malagasy cichlids are entirely restricted to fresh water, Ptychochromis grandidieri and Paretroplus polyactis are commonly found in coastal brackish water and apparently are salt tolerant,{{cite journal |last1=Stiassny |first1=Melanie L.J |last2=Sparks |first2=John S |date=2006 |title=Phylogeny and Taxonomic Revision of the Endemic Malagasy Genus Ptychochromis (Teleostei: Cichlidae), with the Description of Five New Species and a Diagnosis for Katria, New Genus |url=https://www.biodiversitylibrary.org/itempdf/280948 |journal=American Museum Novitates |issue=3535 |page=1 |doi=10.1206/0003-0082(2006)3535[1:PATROT]2.0.CO;2 |s2cid=322493}}{{cite journal |last1=Sparks |first1=John S. |date=2008 |title=Phylogeny of the Cichlid Subfamily Etroplinae and Taxonomic Revision of the Malagasy Cichlid Genus Paretroplus (Teleostei: Cichlidae) |journal=Bulletin of the American Museum of Natural History |volume=314 |issue=1 |page=1 |doi=10.1206/314.1 |s2cid=84071748}} as is also the case for Etroplus maculatus and E. suratensis from India and Sri Lanka.{{FishBase|genus=Etroplus|species=maculatus|date=July 2011}}{{FishBase|genus=Etroplus|species=suratensis|date=July 2011}}

{{More citations needed|date=October 2014}}

Within the cichlid family, carnivores, herbivores, omnivores, planktivores, and detritivores are known, meaning the Cichlidae encompass essentially the full range of food consumption possible in the animal kingdom. Various species have morphological adaptations for specific food sources,{{cite web |last1=Kullander |first1=S.O. |title=Family Cichlidae-Cichlids |url=https://www.fishbase.se/Summary/FamilySummary.php?ID=349 |website=FishBase |access-date=4 December 2019}} but most cichlids consume a wider variety of foods based on availability.

Carnivorous cichlids can be further divided into piscivorous and molluscivorous, since the morphology and hunting behavior differ greatly between the two categories. Piscivorous cichlids eat other fish, fry, larvae, and eggs. Some species eat the offspring of mouthbrooders by head-ramming, wherein the hunter shoves its head into the mouth of a female to expel her young and eat them.{{cite web |last1=Jonna |first1=R. Jamil |title=Cichlidae |url=https://animaldiversity.org/accounts/Cichlidae/ |website=Animal Diversity Web |publisher=University of Michigan Museum of Zoology |access-date=3 December 2019}} Molluscivorous cichlids have several hunting strategies amongst the varieties within the group. Lake Malawi cichlids consume substrate and filter it out through their gill rakers to eat the mollusks that were in the substrate. Gill rakers are finger-like structures that line the gills of some fish to catch any food that might escape through their gills.{{cite book |doi=10.1016/B978-0-12-375060-0.00003-6 |chapter=The Shark |title=The Dissection of Vertebrates |year=2011 |last1=De Iuliis |first1=Gerardo |last2=Pulerà |first2=Dino |pages=27–77 |isbn=978-0-12-375060-0 }}

File:Pseudotropheus Crabo Male.JPG, is specialised in feeding on parasites from the catfish Bagrus meridionalis.{{cite journal |last1=Ribbink |first1=A.J. |last2=Lewis |first2=D.S.C. |title=Melanochromis Crabro Sp. Nov.: a Cichlid Fish From Lake Malawi Which Feeds On Ectoparasites and Catfish Eggs |journal=Netherlands Journal of Zoology |date=1981 |volume=32 |issue=1 |pages=72–87 |doi=10.1163/002829682X00058 }}]]

Many cichlids are primarily herbivores, feeding on algae (e.g. Petrochromis) and plants (e.g. Etroplus suratensis). Small animals, particularly invertebrates, are only a minor part of their diets.

Other cichlids are detritivores and eat organic material, called Aufwuchs (offal); among these species are the tilapiines of the genera Oreochromis, Sarotherodon, and Tilapia.

Other cichlids are predatory and eat little or no plant matter. These include generalists that catch a variety of small animals, including other fishes and insect larvae (e.g. Pterophyllum), as well as variety of specialists. Trematocranus is a specialized snail-eater, while Pungu maclareni feeds on sponges. A number of cichlids feed on other fish, either entirely or in part. Crenicichla species are stealth predators that lunge from concealment at passing small fish, while Rhamphochromis species are open-water pursuit predators that chase down their prey.{{cite web| author = Oliver, M.K. | date = 18 November 1999 | url = http://malawicichlids.com/mw08096.htm | title = Rhamphochromis esox | publisher = malawicichlids.com: The Cichlid Fishes of Lake Malawi| access-date = 19 April 2007}} Paedophagous cichlids such as the Caprichromis species eat other species' eggs or young, in some cases ramming the heads of mouthbrooding species to force them to disgorge their young.{{cite journal | author = Ribbink, A.J.| author2 = Ribbink, A.C. | year = 1997 | title = Paedophagia among cichlid fishes of Lake Victoria and Lake Malawi/Nyasa | journal = South African Journal of Science | volume = 93 | pages = 509–512}}{{cite journal|author = McKaye, K.R.| author2 = Kocher, T. | year = 1983| title = Head ramming behaviour by three paedophagous cichlids in Lake Malawi, Africa | journal = Animal Behaviour | volume = 31 | pages = 206–210 | doi = 10.1016/S0003-3472(83)80190-0| s2cid = 53156766 }}{{cite journal | author = Wilhelm, W. | year = 1980 | title = The disputed feeding behavior of a paedophagous haplochromine cichlid (Pisces) observed and discussed | journal = Behaviour | volume = 74 | pages = 310–322 | doi = 10.1163/156853980X00528 | issue = 3}}{{cite journal | author = Konings, A. | year = 2007 | title = Paedophagy in Malawi cichlids | journal = Cichlid News | volume = 16 | pages = 28–32}} Among the more unusual feeding strategies are those of Corematodus, Docimodus evelynae, Plecodus, Perissodus, and Genyochromis spp., which feed on scales and fins of other fishes, a behavior known as lepidophagy,{{cite journal | author = Trewavas, E. | year = 1947 | title = An example of "mimicry" in fishes | journal = Nature | volume = 160| pages = 120 | doi = 10.1038/160120a0 | pmid = 20256157 | issue=4056| bibcode = 1947Natur.160..120T | s2cid = 4140785 | doi-access = free }}{{cite journal | author = Eccles, D.H. | author2 = D.S.C. Lewis | year = 1976 | title = A taxonomic study of the genus Docimodus Boulenger (Pisces, Cichlidae) a group of fishes with unusual feeding habits from Lake Malawi | journal = Zoological Journal of the Linnean Society | volume = 58 | pages = 165–172 | doi = 10.1111/j.1096-3642.1976.tb00826.x | issue = 2}}{{cite journal | author = Nshombo, M. | year = 1991 | title = Occasional egg-eating by the scale-eater Plecodus straeleni (Cichlidae) of Lake Tanganyika | journal = Environmental Biology of Fishes | volume = 31 | pages = 207–212 | doi = 10.1007/BF00001022 | issue = 2| bibcode = 1991EnvBF..31..207N | s2cid = 38219021 }} along with the death-mimicking behaviour of Nimbochromis and Parachromis species, which lay motionless, luring small fish to their side prior to ambush.{{cite journal | author = Tobler, M. | year = 2005 | title = Feigning death in the Central American cichlid Parachromis friedrichsthalii | journal = Journal of Fish Biology | volume = 66 | pages = 877–881 | doi = 10.1111/j.0022-1112.2005.00648.x | issue = 3| bibcode = 2005JFBio..66..877T }}{{cite journal | author = McKaye, K.R. | year = 1981 | title = Field observation on death feigning: a unique hunting behavior by the predatory cichlid, Haplochromis livingstoni, of Lake Malawi | journal = Environmental Biology of Fishes | volume = 6 | pages = 361–365 | doi = 10.1007/BF00005766 | issue = 3–4| bibcode = 1981EnvBF...6..361M | s2cid = 24244576 }}

This variety of feeding styles has helped cichlids to inhabit similarly varied habitats. Its pharyngeal teeth (in the throat) afford cichlids so many "niche" feeding strategies, because the jaws pick and hold food, while the pharyngeal teeth crush the prey.

Aggressive behavior in cichlids is ritualized and consists of multiple displays used to seek confrontation while being involved in evaluation of competitors,{{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}} coinciding with temporal proximity to mating. Displays of ritualized aggression in cichlids include a remarkably rapid change in coloration, during which a successfully dominant territorial male assumes a more vivid and brighter coloration, while a subordinate or "nonterritorial" male assumes a dull-pale coloration.{{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 }} In addition to color displays, cichlids employ their lateral lines to sense movements of water around their opponents to evaluate the competing male for physical traits/fitness.{{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 }} Male cichlids are very territorial due to the pressure of reproduction, and establish their territory and social status by physically driving out{{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 }} challenging males (novel intruders){{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}} through lateral displays (parallel orientation, uncovering gills),{{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}} 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 (mates, territory, food). Female cichlids prefer to mate with a successfully alpha male with vivid coloration, whose territory has food readily available.

Cichlids mate either monogamously or polygamously. 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.{{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}}

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.{{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}}

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.{{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}} 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.

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.{{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 }} The presence of egg spots in a turbid riverine environment would seem particularly beneficial and necessary for intraspecies communication.

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. 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

The cichlid Benitochromis nigrodorsalis from Western Africa ordinarily undergoes biparental reproduction, but is also able to undergo facultative (optional) selfing (self-fertilization).Böhne A, Oğuzhan Z, Chrysostomakis I, Vitt S, Meuthen D, Martin S, Kukowka S, Thünken T. Evidence for selfing in a vertebrate from whole-genome sequencing. Genome Res. 2023 Dec 27;33(12):2133-2142. doi: 10.1101/gr.277368.122. PMID 38190641; PMCID: PMC10760518 Facultative selfing may be an adaptive option when a mating partner is unavailable.

{{Further|List of fish species that protect their young}}

Pit spawning, also referred to as substrate breeding, is a behavior in cichlid fish in which a fish builds a pit in the sand or ground, where a pair court and consequently spawn.{{cite journal |last1=Alonso |first1=Felipe |last2=Cánepa |first2=Maximiliano |last3=Moreira |first3=Renata Guimarães |last4=Pandolfi |first4=Matías |date=22 July 2011 |title=Social and reproductive physiology and behavior of the Neotropical cichlid fish Cichlasoma dimerus under laboratory conditions |journal=Neotropical Ichthyology |volume=9 |issue=3 |pages=559–570 |doi=10.1590/S1679-62252011005000025 |doi-access=free |hdl=20.500.12110/paper_16796225_v9_n3_p559_Alonso |hdl-access=free }} Many different factors go into this behavior of pit spawning, including female choice of the male and pit size, as well as the male defense of the pits once they are dug in the sand.{{cite journal |last=Nelson |first=C. Mindy |date=1 January 1995 |title=Male size, spawning pit size and female mate choice in a lekking cichlid fish |journal=Animal Behaviour |volume=50 |issue=6 |pages=1587–1599 |doi=10.1016/0003-3472(95)80013-1 |s2cid=54249065 |doi-access=free }}

Cichlids are often divided into two main groups: mouthbrooders and substrate brooders. Different parenting investment levels and behaviors are associated with each type of reproduction.{{cite journal |last1=Duponchelle |first1=Fabrice |last2=Paradis |first2=Emmanuel |last3=Ribbink |first3=Anthony J. |last4=Turner |first4=George F. |title=Parallel life history evolution in mouthbrooding cichlids from the African Great Lakes |journal=Proceedings of the National Academy of Sciences |date=7 October 2008 |volume=105 |issue=40 |pages=15475–15480 |doi=10.1073/pnas.0802343105 |pmid=18824688 |pmc=2563094 |bibcode=2008PNAS..10515475D |doi-access=free }} As pit spawning is a reproductive behavior, many different physiological changes occur in the cichlid while this process is occurring that interfere with social interaction.{{cite journal |last1=Brown |first1=Dean H. |last2=Marshall |first2=Joseph A. |title=Reproductive Behaviour of the Rainbow Cichlid, Herotilapia Multispinosa (Pisces, Cichlidae) |journal=Behaviour |date=1978 |volume=67 |issue=3–4 |pages=299–321 |doi=10.1163/156853978X00378 }} Different kinds of species that pit spawn, and many different morphological changes occur because of this behavioral experience.

Pit spawning is an evolved behavior across the cichlid group. Phylogenetic evidence from cichlids in Lake Tanganyika could be helpful in uncovering the evolution of their reproductive behaviors.{{cite journal |last1=Muschick |first1=Moritz |last2=Indermaur |first2=Adrian |last3=Salzburger |first3=Walter |title=Convergent Evolution within an Adaptive Radiation of Cichlid Fishes |journal=Current Biology |date=December 2012 |volume=22 |issue=24 |pages=2362–2368 |doi=10.1016/j.cub.2012.10.048 |pmid=23159601 |s2cid=18363916 |doi-access=free |bibcode=2012CBio...22.2362M }} Several important behaviors are associated with pit spawning, including parental care, food provisioning,{{cite journal |last1=Wisenden |first1=Brian D. |last2=Lanfranconi-Izawa |first2=Tanya L. |last3=Keenleyside |first3=Miles H.A. |title=Fin digging and leaf lifting by the convict cichlid, Cichlasoma nigrofasciatum: examples of parental food provisioning |journal=Animal Behaviour |date=March 1995 |volume=49 |issue=3 |pages=623–631 |doi=10.1016/0003-3472(95)80195-2 |s2cid=41529998 }} and brood guarding.{{cite journal |last1=Ota |first1=Kazutaka |last2=Kohda |first2=Masanori |title=Maternal Food Provisioning in a Substrate-Brooding African Cichlid |journal=PLOS ONE |date=9 June 2014 |volume=9 |issue=6 |pages=e99094 |doi=10.1371/journal.pone.0099094 |pmid=24911060 |pmc=4049616 |bibcode=2014PLoSO...999094O |doi-access=free }}

One of the differences studied in African cichlids is reproductive behavior. Some species pit spawn and some are known as mouth brooders. Mouthbrooding is a reproductive technique where the fish scoop up eggs and fry for protection. While this behavior differs from species to species in the details, the general basis of the behavior is the same. Mouthbrooding also affects how they choose their mates and breeding grounds. In a 1995 study, Nelson found that in pit-spawning females choose males for mating based on the size of the pit that they dig, as well as some of the physical characteristics seen in the males. Pit spawning also differs from mouth brooding in the size and postnatal care exhibited. Eggs that have been hatched from pit-spawning cichlids are usually smaller than those of mouthbrooders. Pit-spawners' eggs are usually around 2 mm, while mouthbrooders are typically around 7 mm. While different behaviors take place postnatally between mouthbrooders and pit spawners, some similarities exist. Females in both mouthbrooders and pit-spawning cichlids take care of their young after they are hatched. In some cases, both parents exhibit care, but the female always cares for the eggs and newly hatched fry.{{cite journal |last1=Sefc |first1=Kristina M. |date=21 July 2011 |title=Mating and parental care in Lake Tanganyika's cichlids |journal=International Journal of Evolutionary Biology |volume=2011 |page=470875 |doi=10.4061/2011/470875 |pmid=21822482 |pmc=3142683 |doi-access=free }}

Many species of cichlids use pit spawning, but one of the less commonly studied species that exhibits this behavior is the Neotropical Cichlasoma dimerus. This fish is a substrate breeder that displays biparental care after the fry have hatched from their eggs. One study examined reproductive and social behaviors of this species to see how they accomplished their pit spawning, including different physiological factors such as hormone levels, color changes, and plasma cortisol levels. The entire spawning process could take about 90 minutes and 400~800 eggs could be laid. The female deposits about 10 eggs at a time, attaching them to the spawning surface, which may be a pit constructed on the substrate or another surface. The number of eggs laid was correlated to the space available on the substrate. Once the eggs were attached, the male swam over the eggs and fertilized them. The parents would then dig pits in the sand, 10–20 cm wide and 5–10 cm deep, where larvae were transferred after hatching. Larvae began swimming 8 days after fertilization and parenting behaviors and some of the physiological factors measured changed.

In the same study, color changes were present before and after the pit spawning occurred. For example, after the larvae were transferred and the pits were beginning to be protected, their fins turned a dark grey color. In another study, of the rainbow cichlid, Herotilapia multispinosa, color changes occurred throughout the spawning process. Before spawning, the rainbow cichlid was an olive color with grey bands. Once spawning behaviors started, the body and fins of the fish became a more golden color. When the eggs were finished being laid, the pelvic fin all the way back to the caudal fin turned to a darker color and blackened in both the males and the females.

Females prefer a bigger pit size when choosing where to lay eggs. Differences are seen in the sizes of pits that created, as well as a change in the morphology of the pits.{{cite journal |last1=York |first1=Ryan A. |last2=Patil |first2=Chinar |last3=Hulsey |first3=C. Darrin |last4=Streelman |first4=J. Todd |last5=Fernald |first5=Russell D. |title=Evolution of bower building in Lake Malawi cichlid fish: phylogeny, morphology, and behavior |journal=Frontiers in Ecology and Evolution |date=27 February 2015 |volume=3 |doi=10.3389/fevo.2015.00018 |s2cid=7458974 |doi-access=free }} Evolutionary differences between species of fish may cause them to either create pits or castles when spawning. The differences were changes in the way that each species fed, their macrohabitats, and the abilities of their sensory systems.

Cichlids are renowned for their recent, rapid evolutionary radiation, both across the entire clade and within different communities across separate habitats.{{cite journal |last1=Goodwin |first1=Nicholas B. |last2=Balshine-Earn |first2=Sigal |last3=Reynolds |first3=John D. |title=Evolutionary transitions in parental care in cichlid fish |journal=Proceedings of the Royal Society of London. Series B: Biological Sciences |date=7 December 1998 |volume=265 |issue=1412 |pages=2265–2272 |doi=10.1098/rspb.1998.0569 |pmc=1689529 }}{{cite journal |last1=Hulsey |first1=C Darrin |last2=Hollingsworth |first2=Phillip R |last3=Fordyce |first3=James A |title=Temporal diversification of Central American cichlids |journal=BMC Evolutionary Biology |date=December 2010 |volume=10 |issue=1 |pages=279 |doi=10.1186/1471-2148-10-279 |pmid=20840768 |pmc=2944184 |doi-access=free |bibcode=2010BMCEE..10..279H }} Within their phylogeny, many parallel instances are seen of lineages evolving to the same trait and multiple cases of reversion to an ancestral trait.

The family Cichlidae arose between 80 and 100 million years ago within the order Perciformes (perch-like fishes).{{cite journal |last1=Zardoya |first1=Rafael |last2=Vollmer |first2=Dana M. |last3=Craddock |first3=Clark |last4=Streelman |first4=Jeffrey T. |last5=Karl |first5=Steve |last6=Meyer |first6=Axel |date=22 November 1996 |title=Evolutionary conservation of microsatellite flanking regions and their use in resolving the phylogeny of cichlid fishes (Pisces: Perciformes) |journal=Proceedings of the Royal Society of London |series=Series B: Biological Sciences |volume=263 |issue=1376 |pages=1589–1598 |doi=10.1098/rspb.1996.0233 |pmid=8952095 |bibcode=1996RSPSB.263.1589Z |s2cid=45834758 |url=http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-36277 }} Cichlidae can be split into a few groups based on their geographic location: Madagascar, Indian, African, and Neotropical (or South American). The most famous and diverse group, the African cichlids, can be further split either into Eastern and Western varieties, or into groups depending on which lake the species is from: Lake Malawi, Lake Victoria, or Lake Tanganyika. Of these subgroups, the Madagascar and Indian cichlids are the most basal and least diverse.{{citation needed|date=November 2020}}

Of the African cichlids, the West African or Lake Tanganyika cichlids are the most basal.

Cichlids' common ancestor is believed to have been a spit-spawning species. Both Madagascar and Indian cichlids retain this feature. However, of the African cichlids, all extant substrate brooding species originate solely from Lake Tanganyika. The ancestor of the Lake Malawi and Lake Victoria cichlids were mouthbrooders. Similarly, only around 30% of South American cichlids are thought to retain the ancestral substrate-brooding trait. Mouthbrooding is thought to have evolved individually up to 14 times, and a return to substrate brooding as many as three separate times between both African and Neotropical species.

Cichlids have a great variety of behaviors associated with substrate brooding, including courtship and parental care alongside the brooding and nest-building behaviors needed for pit spawning. Cichlids' behavior typically revolves around establishing and defending territories when not courting, brooding, or raising young. Encounters between males and males or females and females are agonistic, while an encounter between a male and female leads to courtship.{{cite journal |last1=Burchard |first1=John E. |title=Family Structure in the Dwarf Cichlid Apistogramma trifasciatum Eigenmann and Kennedy) |journal=Zeitschrift für Tierpsychologie |date=26 April 2010 |volume=22 |issue=2 |pages=150–162 |doi=10.1111/j.1439-0310.1965.tb01428.x |pmid=5890861 }} Courtship in male cichlids follows the establishment of some form of territory, sometimes coupled with building a bower to attract mates. After this, males may attempt to attract female cichlids to their territories by a variety of lekking display strategies or otherwise seek out females of their species. However, cichlids, at the time of spawning, undergo a behavioral change such that they become less receptive to outside interactions. This is often coupled with some physiological change in appearance.

Cichlids can have maternal, paternal, or biparental care. Maternal care is most common among mouthbrooders, but cichlids' common ancestor is thought to exhibit paternal-only care. Other individuals outside of the parents may also play a role in raising young; in the biparental daffodil cichlid (Neolamprologus pulcher), closely related satellite males, those males that surround other males' territories and attempt to mate with female cichlids in the area, help rear the primary males' offspring and their own.{{cite journal |last1=Dierkes |first1=P. |title=Reproductive parasitism of broodcare helpers in a cooperatively breeding fish |journal=Behavioral Ecology |date=1 September 1999 |volume=10 |issue=5 |pages=510–515 |doi=10.1093/beheco/10.5.510 |doi-access=free }}

A common form of brood care involves food provisioning. For example, females of lyretail cichlids (Neolamprologus modabu) dig at sandy substrate more to push nutritional detritus and zooplankton into the surrounding water. Adult of N. modabu perform this strategy to collect food for themselves, but dig more when offspring are present, likely to feed their fry.{{cite book |last1=Zworykin |first1=Dmitry |chapter=Parental brood provisioning in cichlid fishes by means of stirring up of the loose material of bottom substrate: a brief review |date=2001 |doi=10.13140/2.1.1937.5048 |title=Cichlid Research: State of the Art |pages=269–286 }} This substrate-disruption strategy is rather common and can also be seen in convict cichlids (Cichlasoma nigrofasciatum). Other cichlids have an ectothermal mucus that they grow and feed to their young, while still others chew and distribute caught food to offspring. These strategies, however, are less common in pit-spawning cichlids.

File:Managuense with eggs.jpg, guards a clutch of eggs in the aquarium.|alt=]]

Cichlids have highly organized breeding activities. All species show some form of parental care for both eggs and larvae, often nurturing free-swimming young until they are weeks or months old.

Communal parental care, where multiple monogamous pairs care for a mixed school of young have also been observed in multiple cichlid species, including Amphilophus citrinellus, Etroplus suratensis, and Tilapia rendalli.{{cite journal |author= McKaye, K.R.|author2 = N.M. McKaye | year = 1977 | title = Communal Care and Kidnapping of Young by Parental Cichlids| journal = Evolution | volume = 31 | pages = 674–681 | doi = 10.2307/2407533 |pmid = 28563477 |issue= 3 |jstor= 2407533}}{{cite journal | author = Ward, J.A. |author2 = Wyman, R.L. |year = 1977| title= Ethology and ecology of cichlid fishes of the genus Etroplus in Sri Lanka: Preliminary findings | journal = Environmental Biology of Fishes | volume = 2 | issue = 2 | pages = 137–145 | doi = 10.1007/BF00005369 |bibcode = 1977EnvBF...2..137W |s2cid = 8307811 }}{{cite journal | author = Ribbink, A.J. |author2 = Marsh, A.C. |author3 = Marsh, B.A. | year = 1981 | title = Nest-building and communal care of young by Tilapia rendalli dumeril (pisces, cichlidae) in Lake Malawi | journal = Environmental Biology of Fishes | volume = 6 | pages = 219–222 | doi = 10.1007/BF00002787 | issue = 2|bibcode = 1981EnvBF...6..219R | s2cid = 9546191 }} Comparably, the fry of Neolamprologus brichardi, a species that commonly lives in large groups, are protected not only by the adults, but also by older juveniles from previous spawns.Steeves, Greg. [http://www.africancichlids.net/articles/neolamprologus_brichardi/ Neolamprologus brichardi.] {{Webarchive|url=https://web.archive.org/web/20080505172935/http://www.africancichlids.net/articles/neolamprologus_brichardi/ |date=5 May 2008 }} africancichlids.net. Retrieved 8 April 2008 Several cichlids, including discus (Symphysodon spp.), some Amphilophus species, Etroplus, and Uaru species, feed their young with a skin secretion from mucous glands.

The species Neolamprologus pulcher uses a cooperative breeding system, in which one breeding pair has many helpers that are subordinate to the dominant breeders.

Parental care falls into one of four categories: substrate or open brooders, secretive cave brooders (also known as guarding speleophils{{cite journal |author=Balon, E.K. |year=1975 |title=Reproductive guilds of fishes: A proposal and definition |journal=Journal of the Fisheries Research Board of Canada |volume=32 |issue=6 |pages=821–864 |doi=10.1139/f75-110 }}), and at least two types of mouthbrooders, ovophile mouthbrooders and larvophile mouthbrooders.{{cite book |last=Keenleyside |first=M.H.A. |year=1991 |chapter=Parental care |title=Cichlid Fishes: Behaviour, ecology and evolution |publisher=Chapman and Hall |place=London, UK |pages=191–208 |isbn=978-0-412-32200-6}}

Open- or substrate-brooding cichlids lay their eggs in the open, on rocks, leaves, or logs. Examples of open-brooding cichlids include Pterophyllum and Symphysodon species and Anomalochromis thomasi. Male and female parents usually engage in differing brooding roles. Most commonly, the male patrols the pair's territory and repels intruders, while the female fans water over the eggs, removing the infertile ones, and leading the fry while foraging. Both sexes are able to perform the full range of parenting behaviours.

File:Cyphotilapia frontosa mouthbrooding.jpg mouthbrooding fry, which can be seen looking out of her mouth]]

Secretive cave-spawning cichlids lay their eggs in caves, crevices, holes, or discarded mollusc shells, frequently attaching the eggs to the roof of the chamber. Examples include Pelvicachromis spp., Archocentrus spp., and Apistogramma spp. Free-swimming fry and parents communicate in captivity and in the wild. Frequently, this communication is based on body movements, such as shaking and pelvic fin flicking. In addition, open- and cave-brooding parents assist in finding food resources for their fry. Multiple neotropical cichlid species perform leaf-turning and fin-digging behaviors.

Ovophile mouthbrooders incubate their eggs in their mouths as soon as they are laid, and frequently mouthbrood free-swimming fry for several weeks. Examples include many East African Rift lakes (Lake Malawi, Lake Tanganyika, and Lake Victoria) endemics, e.g.: Maylandia, Pseudotropheus, Tropheus, and Astatotilapia burtoni, along with some South American cichlids such as Geophagus steindachneri.

Larvophile mouthbrooders lay eggs in the open or in a cave and take the hatched larvae into the mouth. Examples include some variants of Geophagus altifrons, and some Aequidens, Gymnogeophagus, and Satanoperca, as well as Oreochromis mossambicus and Oreochromis niloticus. Mouthbrooders, whether of eggs or larvae, are predominantly females. Exceptions that also involve the males include eretmodine cichlids (genera Spathodus, Eretmodus, and Tanganicodus), some Sarotherodon species (such as Sarotherodon melanotheron{{cite journal |last1=Kishida |first1=Mitsuyo |last2=Specker |first2=Jennifer L. |date=February 2000 |title=Paternal mouthbrooding in the black-chinned tilapia, Sarotherodon melanotheron (Pisces: Cichlidae): Changes in gonadal steroids and potential for vitellogenin transfer to larvae |journal=Hormones and Behavior |volume=37 |issue=1 |pages=40–48 |doi=10.1006/hbeh.1999.1556 |pmid=10712857 |s2cid=8128737 }}), Chromidotilapia guentheri, and some Aequidens species.{{cite journal | author = Coleman, R. |date=January 1999 | title = Mysterious mouthbrooders | journal = Cichlid News | pages = 32–33}} This method appears to have evolved independently in several groups of African cichlids.

File:ChiclidPhylogeny4TC.jpg evolved from an original hybrid swarm.]]

Cichlids provide scientists with a unique perspective of speciation, having become extremely diverse in the recent geological past, those of Lake Victoria actually within the last 10,000 to 15,000 years, a small fraction of the millions taken for Galápagos finch speciation in Darwin's textbook case.{{cite magazine |first=Axel |last=Meyer |date=April 2015 |title=The extraordinary evolution of cichlid fishes |magazine=Scientific American |url=https://www.scientificamerican.com/article/the-extraordinary-evolution-of-cichlid-fishes/ |access-date=29 April 2023}} Some of the contributing factors to their diversification are believed to be the various forms of prey processing displayed by cichlid pharyngeal jaw apparatuses. These different jaw apparatuses allow for a broad range of feeding strategies, including algae scraping, snail crushing, planktivory, piscivory, and insectivory.{{cite journal |last1 = Albertson |first1 = R.C. |last2 = Markert |first2 = J.A. |last3 = Danley |first3 = P.D. |last4 = Kocher |first4 = T.D. |year = 1999 |title = Phylogeny of a rapidly evolving clade: The cichlid fishes of Lake Malawi, East Africa |journal = PNAS |volume = 96 |issue = 9 |pages = 5107–5110 |doi=10.1073/pnas.96.9.5107| pmid = 10220426 |pmc = 21824 | bibcode = 1999PNAS...96.5107A |doi-access = free }} Some cichlids can also show phenotypic plasticity in their pharyngeal jaws, which can also help lead to speciation. In response to different diets or food scarcity, members of the same species can display different jaw morphologies that are better suited to different feeding strategies. As species members begin to concentrate around different food sources and continue their lifecycle, they most likely spawn with like individuals. This can reinforce the jaw morphology and given enough time, create new species.{{cite journal |last1 = Muschick |first1 = M. |last2 = Barluenga |first2 = M. |last3 = Salzburger |first3 = W. |last4 = Meyer |first4 = A. |year = 2011 |title = Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation |journal = BMC Evolutionary Biology |volume = 11 |issue = 1 |page = 116 |doi=10.1186/1471-2148-11-116 |pmid=21529367 |pmc=3103464 |doi-access = free |bibcode = 2011BMCEE..11..116M }} Such a process can happen through allopatric speciation, whereby species diverge according to different selection pressures in different geographical areas, or through sympatric speciation, by which new species evolve from a common ancestor while remaining in the same area. In Lake Apoyo in Nicaragua, Amphilophus zaliosus and its sister species Amphilophus citrinellus display many of the criteria needed for sympatric speciation.{{cite journal |last1 = Barluenga |first1 = M. |last2 = Meyer |first2 = A. |last3 = Muschick |first3 = M. |last4 = Salzburger |first4 = W. |last5 = Stolting |first5 = K.N. |year = 2006 |title = Sympatric speciation in Nicaraguan crater lake cichlid fish |journal = Nature |volume = 439 |issue = 7077 |pages = 719–23 |doi=10.1038/nature04325 |pmid=16467837 |bibcode = 2006Natur.439..719B |s2cid = 3165729 |url = https://kops.uni-konstanz.de/bitstream/123456789/6577/1/sympatric_speciation_in_nicaraguan_crater_lake_cichlid_fish_2006.pdf }} In the African rift lake system, cichlid species in numerous distinct lakes evolved from a shared hybrid swarm.{{cite journal |title=Ancient hybridization fuels rapid cichlid fish adaptive radiations |first1=Joana I. |last1=Meier |first2=David A. |last2=Marques |first3=Salome |last3=Mwaiko |first4=Catherine E. |last4=Wagner |first5=Laurent |last5=Excoffier|first6=Ole |last6=Seehausen |date=10 February 2017 |journal=Nature Communications |volume=8 |page=14363 |doi=10.1038/ncomms14363 |doi-access=free |pmid=28186104 |pmc=5309898 |bibcode=2017NatCo...814363M}}

In 2010, the International Union for Conservation of Nature classified 184 species as vulnerable, 52 as endangered, and 106 as critically endangered.{{cite report |publisher=IUCN |year=2010 |url=http://www.iucnredlist.org/ |title=IUCN Red List of Threatened Species |version=2010.4. |access-date=26 April 2011}}

IUCN does not allow linking to search results. Use "Other Search Options" on the IUCN frontpage, then choose "Cichlidae" (Animalia→Chordata→Actinopterygii→Perciformes) under taxonomy, and then the specific threat category (Vulnerable, Endangered, etc.) under Assessment.

At present, the IUCN only lists Yssichromis sp. nov. argens as extinct in the wild, and six species are listed as entirely extinct, but many more possibly belong in these categories (for example, Haplochromis aelocephalus, H. apogonoides, H. dentex, H. dichrourus, and numerous other members of the genus Haplochromis have not been seen since the 1980s, but are maintained as critically endangered on the small chance that tiny –but currently unknown– populations survive).

{{Main|Lake Victoria#Cichlid fish}}

File:Haplochromis thereuterion.jpg thereuterion has declined, but still survives in low numbers.{{Cite iucn |author1=Witte, F. |author2=de Zeeuw, M.P. |author3=Brooks, E. |year = 2010 | title = Haplochromis thereuterion | volume = 2010 | page = e.T185857A8492470 | doi = 10.2305/IUCN.UK.2010-3.RLTS.T185857A8492470.en }}]]

Because of the introduced Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), and water hyacinth, deforestation that led to water siltation, and overfishing, many Lake Victoria cichlid species have become extinct or been drastically reduced. By around 1980, lake fisheries yielded only 1% cichlids, a drastic decline from 80% in earlier years.

By far the largest Lake Victoria group is the haplochromine cichlids, with more than 500 species, but at least 200 of these (about 40%) have become extinct,{{cite news |last1=Deweerdt |first1=Sarah |title=Dark secret of the lake |url=https://www.newscientist.com/article/mg18124365-300-dark-secret-of-the-lake/ |work=New Scientist |date=28 February 2004 }}{{cite journal |last1=Lowe-McConnell |first1=Rosemary |title=Fisheries and Cichlid Evolution in the African Great Lakes: Progress and Problems |journal=Freshwater Reviews |date=December 2009 |volume=2 |issue=2 |pages=131–151 |doi=10.1608/frj-2.2.2 |s2cid=54011001 }}{{cite journal |last1=van Rijssel |first1=Jacco C. |last2=Witte |first2=Frans |title=Adaptive responses in resurgent Lake Victoria cichlids over the past 30 years |journal=Evolutionary Ecology |date=March 2013 |volume=27 |issue=2 |pages=253–267 |doi=10.1007/s10682-012-9596-9 |bibcode=2013EvEco..27..253V |s2cid=2291741 }} and many others are seriously threatened.{{cite book |editor1=Fiedler, P.L. |editor2=Kareiva, P.M. |year=1998 |title=Conservation Biology: For the coming decade |edition=2nd |pages=209–210 |publisher=Springer |isbn=978-0412096617}} Initially it was feared that the percentage of extinct species was even higher,{{cite journal |last1=Goldschmidt |first1=Tijs |last2=Witte |first2=Frans |last3=Wanink |first3=Jan |title=Cascading Effects of the Introduced Nile Perch on the Detritivorous/Phytoplanktivorous Species in the Sublittoral Areas of Lake Victoria |journal=Conservation Biology |date=September 1993 |volume=7 |issue=3 |pages=686–700 |doi=10.1046/j.1523-1739.1993.07030686.x |bibcode=1993ConBi...7..686G |s2cid=39341574 |url=http://pdfs.semanticscholar.org/1a6d/6d92438f01af8b9fa7f01fc9be4b92af020c.pdf |archive-url=https://web.archive.org/web/20190219194240/http://pdfs.semanticscholar.org/1a6d/6d92438f01af8b9fa7f01fc9be4b92af020c.pdf |url-status=dead |archive-date=2019-02-19 }} but some species have been rediscovered after the Nile perch started to decline in the 1990s.IUCN Red Lists: [http://www.iucnredlist.org/initiatives/freshwater/eastafrica/geographicpatternsea Geographic Patterns]. Eastern Africa. Retrieved 25 March 2017. Some species have survived in nearby small satellite lakes, or in refugia among rocks or papyrus sedges (protecting them from the Nile perch),{{cite journal |last1=Chapman |first1=Lauren J. |last2=Chapman |first2=Colin A. |last3=Chandler |first3=Mark |title=Wetland ecotones as refugia for endangered fishes |journal=Biological Conservation |date=December 1996 |volume=78 |issue=3 |pages=263–270 |doi=10.1016/s0006-3207(96)00030-4 |bibcode=1996BCons..78..263C |citeseerx=10.1.1.689.2625 }} or have adapted to the human-induced changes in the lake itself. The species were often specialists and these were not affected to the same extent. For example, the piscivorous haplochromines were particularly hard hit with a high number of extinctions,{{cite journal |last1=McGee |first1=M. D. |last2=Borstein |first2=S. R. |last3=Neches |first3=R. Y. |last4=Buescher |first4=H. H. |last5=Seehausen |first5=O. |last6=Wainwright |first6=P. C. |title=A pharyngeal jaw evolutionary innovation facilitated extinction in Lake Victoria cichlids |journal=Science |date=27 November 2015 |volume=350 |issue=6264 |pages=1077–1079 |doi=10.1126/science.aab0800 |pmid=26612951 |bibcode=2015Sci...350.1077M |doi-access=free }} while the zooplanktivorous haplochromines reached densities in 2001 that were similar to before the drastic decline, although consisting of fewer species and with some changes in their ecology.

Although cichlids are mostly small- to medium-sized, many are notable as food and game fishes. With few thick rib bones and tasty flesh, artisan fishing is not uncommon in Central America and South America, as well as areas surrounding the African rift lakes.{{cite book|last=Barlow|first=G. W.|year=2000|title=The Cichlid Fishes|publisher=Cambridge, MA: Perseus Publishing|isbn=978-0-7382-0376-8|url-access=registration|url=https://archive.org/details/cichlidfishesnat00geor_0}}

The most important food cichlids, however, are the tilapiines of North Africa. Fast growing, tolerant of stocking density, and adaptable, tilapiine species have been introduced and farmed extensively in many parts of Asia and are increasingly common aquaculture targets elsewhere.

Farmed tilapia production is about {{convert|1500000|t|ST|abbr=off}} annually, with an estimated value of US$1.8 billion,{{cite book |last1=Silva |first1=Sena S. De |last2=Nations |first2=Food and Agriculture Organization of the United |title=Tilapias as Alien Aquatics in Asia and the Pacific: A Review |date=2004 |publisher=Food & Agriculture Org. |isbn=978-92-5-105227-3 }}{{page needed|date=November 2020}} about equal to that of salmon and trout.

Unlike those carnivorous fish, tilapia can feed on algae or any plant-based food. This reduces the cost of tilapia farming, reduces fishing pressure on prey species, avoids concentrating toxins that accumulate at higher levels of the food chain, and makes tilapia the preferred "aquatic chickens" of the trade.

Many large cichlids are popular game fish. The peacock bass (Cichla species) of South America is one of the most popular sportfish. It was introduced in many waters around the world.{{Where|date=October 2014}} In Florida, this fish generates millions of hours of fishing and sportfishing revenue of more than US$8 million a year.{{cite web|url=http://floridafisheries.com/fishes/non-native.html|title=Fact Exotic Freshwater Fishes|author=Florida Fish and Wildlife Conservation Commission|access-date=18 March 2007}} Other cichlids preferred by anglers include the oscar, Mayan cichlid (Cichlasoma urophthalmus), and jaguar cichlid (Parachromis managuensis).

{{Further|List of cichlid fish of South America}}

File:Discus fish.jpg spp., has been popular among aquarium enthusiasts.]]

Since 1945, cichlids have become increasingly popular as aquarium fish.{{cite book |editor-last=Riehl |editor-first=Rüdiger |author-last=Baensch |author-first=H.A. |title=Aquarium Atlas |year=1996 |edition=5th |publisher=Tetra Press |place=Germany |isbn=978-3-88244-050-8}}{{cite book |author=Sands, D. |year=1994 |title=A Fishkeepers Guide to Central American Cichlids |publisher=Tetra Press |place=Belgium |pages=59–60}}{{cite book |author=Mills, D. |year=1993 |title=Aquarium Fish |publisher=Harper Collins |isbn=0-7322-5012-9}}{{cite book |author=Konings, A. |year=1997 |title=Back to Nature Guide to Malawi Cichlids |publisher=Druckhaus Beltz |place=Germany |pages=13–23}}{{cite book |author=Leibel, W.S. |year=1993 |title=A Fishkeepers Guide to South American Cichlids |publisher=Tetra Press |place=Belgium |pages=12–14}}

The most common species in hobbyist aquaria is Pterophyllum scalare from the Amazon River basin in tropical South America, known in the trade as the "angelfish". Other popular or readily available species include the oscar (Astronotus ocellatus), convict cichlid (Archocentrus nigrofasciatus) and discus fish (Symphysodon).

{{clear}}

File:Red Texas.jpg (Herichthys cyanoguttatus) but a cross-genus hybrid of Herichthys and Amphilophus parents.]]

Some cichlids readily hybridize with related species, both in the wild and under artificial conditions.{{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 }} Other groups of fishes, such as European cyprinids, also hybridize.{{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 }} Unusually, cichlid hybrids have been put to extensive commercial use, in particular for aquaculture and aquaria.{{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}} 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.

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 synspillus {{citation needed|date=January 2019}} With a triangular-shaped mouth, an abnormal 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".{{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}} 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.{{cite news |author=Arnold, W. |date=1 July 2003 |title=Singapore's 'lucky' pet Luohan can outnumber people in homes |newspaper=International Herald Tribune}} The popularity of the flowerhorn cichlid declined in 2004.{{cite news |title=Crayfish the latest fad among pet lovers |newspaper=New Straits Times |place=Singapore, Malaysia |date=3 September 2004}} Owners released many specimens into the rivers and canals of Malaysia and Singapore, where they threaten endemic communities.{{cite news |title=Flower horn: Joy in homes, a pest in rivers |newspaper=New Straits Times |place=Singapore, Malaysia |date=14 July 2004}}

File:Long finned oscar.jpg long-finned form of the oscar, A. ocellatus]]

Numerous cichlid species have been selectively bred to develop ornamental aquarium strains. The most intensive programs have involved angelfish and discus, and many mutations that affect both coloration and fins are known.{{cite magazine |last=Norton |first=J. |year=1982 | title = Angelfish genetics |magazine=Freshwater and Marine Aquarium Magazine |volume=5 |page=4}}{{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 }} Other cichlids have been bred for albino, leucistic, and xanthistic pigment mutations, including oscars, convict cichlid and Pelvicachromis pulcher. Both dominant and recessive pigment mutations have been observed.{{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}} In convict cichlids, for example, a leucistic coloration is recessively inherited,{{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 }} while in Oreochromis niloticus niloticus, red coloration is caused by a dominant inherited mutation.{{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 }}

This selective breeding may have unintended consequences. For example, hybrid strains of Mikrogeophagus ramirezi have health and fertility problems.

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}} Similarly, intentional inbreeding can cause physical abnormalities, such as the notched phenotype in angelfish.{{cite journal |last1=Norton |first1=J |year=1994 |title=Notched – An Angelfish Deformity |journal=Freshwater and Marine Aquarium Magazine |volume=17 |issue=3 }}

The genus list is as per FishBase. Studies are continuing, however, on the members of this family, particularly the haplochromine cichlids of the African rift lakes.

File:Astronotus ocellatus.jpg|The oscar (Astronotus ocellatus) is one of the most popular cichlids in the fishkeeping hobby.

File:ButterflyPeacockBass 01.jpg|The butterfly peacock bass (Cichla ocellaris) was introduced intentionally in Florida as gamefish.

File:Oreochromis niloticus.jpg|The Nile tilapia (Oreochromis niloticus) is farmed extensively as food fish in many parts of the world.

File:Pterophyllum scalare-narybek.jpg|The angelfish (Pterophyllum scalare) has long been commercially bred for the aquarium trade.

File:Maylandia lombardoi.jpg|Sexual dimorphism is common in cichlids. Shown here are a male (front, with egg spots) and a female (rear) Maylandia lombardoi.

File:Mikrogeophagus.jpg|A pair of blue rams (Mikrogeophagus ramirezi), male in front, female behind. Many cichlids form strong pair bonds while breeding.

File:Diskuslaich1a.jpeg|A discus (Symphysodon spp.) is guarding its eggs. Advanced broodcare is one of the defining characteristics of cichlids.

File:Adult_male_livingstonii.png|Lake Malawi, Eastern Africa, is home to numerous cichild species including this Livingston's cichlid (Nimbochromis livingstonii).

File:Maylandia lombardoi male Lake Malawi Cichlid yellow.jpg|Also from Lake Malawi

File:Labeotropheus sp Lake Malawi Cichlid pale femelle.jpg|Also from Lake Malawi

File:Lamprologusstappersimalemcl.jpg|A shell-brooding cichlid of the genus Lamprologus from Lake Tanganyika in East Africa

File:Herichthys cyanoguttatum (Rio Grande Cichlid).jpg|The Texas cichlid (Herichthys cyanoguttatus) is the only cichlid native to the United States.

File:Pelvicachromis pulcher (female).jpg|Pelvicachromis pulcher is a West African riverine cichlid, and part of the aquarists dwarf cichlid group.

File:Flowerhorn.jpg|The flowerhorn cichlid is a man-made hybrid that has recently gained popularity among aquarists, particularly in Asia.

File:Ivanacara adoketa5164.jpg|Ivanacara adoketa, a dwarf cichlid from Brazil

File:Red Terror Festae Chiclid.jpg|The red terror cichlid is a highly aggressive species from the rivers of Northeast South America.

File:Female Juvenile .jpg|A juvenile female Maylandia lombardoi with faint stripes

File:Juvenile Royal Acara.jpg|A juvenile Aequidens diadema

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{{reflist|25em}}

• {{cite book |author=Barlow, G.W. |year=2000 |title=The Cichlid Fishes |place=Cambridge, MA |publisher=Perseus Publishing}}
• {{ITIS |id=169770 |taxon=Cichlidae}}: National Museum of Natural History, Washington, D.C., 2004-05-11).
• {{cite report |author=Sany, R.H. |year=2012 |title=Taxonomy of Cichlids and Angels |type=web publication}}{{full citation needed|date=April 2023|reason=If "web publication" at least needs a URL.}}

{{Commons category|Cichlidae}}

• {{cite web |editor-first=Michael |editor-last=Oliver |date=15 October 2021 |orig-date=7 May 1997 |title=The cichlid fishes of Lake Malawi, Africa |type=main page |website=MalawiCichlids.com |url=http://www.malawicichlids.com/ |access-date=1 May 2023}}
• {{cite report |first=H.J. |last=van der Meer |date=2008–2013 |title=Vision in cichlids: Ecomorphology of vision in haplochromine cichlids of Lake Victoria |url=http://www.vision-in-cichlids.com/}}
• {{cite EB1911 |wstitle=Cichlid |volume=6 |page=360 |short=1}}

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Category:Cichliformes

Category:Extant Lutetian first appearances

Category:Fishkeeping

Category:Taxa named by Charles Lucien Bonaparte