Discus (fish)

{{Short description|Genus of fishes}} {{About|the fish|other uses|Discus (disambiguation)}} {{Automatic taxobox | name = ''Symphysodon'' | image = Blue_Discus.jpg | image_caption = ''Symphysodon aequifasciatus'' | taxon = Symphysodon | authority = Heckel, 1840 | type_species = ''Symphysodon discus'' | type_species_authority = Heckel, 1840 | subdivision_ranks = Species | subdivision= See text }}

'''''Symphysodon''''' (colloquially known as '''discus''' or '''discus fish''') is a genus of cichlids native to the Amazon river basin in Brazil. Due to their distinctive shape, calm behavior, many bright colors and patterns, and dedicated parenting techniques, discus are popular as freshwater aquarium fish, and their aquaculture in several countries in Asia (notably Thailand)<ref>{{cite web|url=https://www.atlasobscura.com/articles/this-obscure-bangkok-market-is-home-to-a-million-dollar-collection-of-tropical-fish|title=This Obscure Bangkok Market is Home to a Million-Dollar Collection of Tropical Fish. In the market for rare aquarium fish? Head to Thailand.|author=Tuccinardi, Michael|date=1 December 2016|publisher=Atlas Obscura|website=www.AtlasObscura.com|quote=''…Discus fish, pre-bagged for a quick sale, occupy a seller's shelves…Each tiny shop or stall usually specializes in a particular breed or category of fish or aquarium—some showcasing colorful but delicate discus and angelfish…''}}</ref> is a major industry.<ref name="Loiselle">{{Cite book |last=Loiselle |first=Paul V. |title=The Cichlid Aquarium |publisher=Tetra Press |year=1995 |isbn=1-56465-146-0 |location=Germany}}</ref><ref name="FKGCC">Sands D (1994) ''A fishkeepers guide to Central American cichlids.'' Tetra Press. Belgium pg 59–60.</ref><ref>Mills D (1993) ''Aquarium Fish'' Harper Collins {{ISBN|0-7322-5012-9}}</ref><ref>{{Cite journal |last1=Chong |first1=K. |last2=Ying, T. S. |last3=Foo, J. |last4=Jin, L. J. |last5=Chong, A. |date=2005-09-12 |title=Characterisation of proteins in epidermal mucus of discus fish (''Symphysodon'' spp.) during parental phase |journal=Aquaculture |volume=249 |issue=1–4 |pages=469–476 |doi=10.1016/j.aquaculture.2005.02.045|bibcode=2005Aquac.249..469C |url=http://scholarbank.nus.edu.sg/handle/10635/100232 }}</ref> They are sometimes referred to as '''pompadour fish'''.<ref>Discus fish - Page 5 Thomas A. Giovanetti, Matthew M. Vriends - 1991 ''"It was not until the 1930s and 1940s that aquarium-fish dealers began importing discus into Europe and the United States under the common name "pompadour fish." Discus are cichlids, which often surprises many aquarists."''</ref><ref>International Wildlife Encyclopedia Set - Page 2006 Robert Burton, Maurice Burton, 2002 ''"Popular aquarium fish because of their bright colors and attractive patterns, pompadour fish are actually quite difficult to keep and require frequent water changes. Pictured are a group of red discus, one of the two species of pompadour fish."''</ref> The discus fish has attracted a cult following of collectors and has created a multimillion dollar international industry complete with shows, competitions, and reputable online breeders{{citation needed|date=September 2021}}.

==Etymology== The genus name "symphysodon", which was coined in 1840 by Johann Jakob Heckel,<ref>{{cite web |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=170023#null |title=Integrated Taxonomic Information System |author= |date= |website= |publisher= |access-date=19 February 2025 }}</ref> refers to the unusual symphysis of the teeth (''-odon'' from Greek ὀδών, tooth).<ref>See [https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=170023#null Wiktionary].</ref>

== Species == Following a review published in 2006,<ref name="ready2006">{{Cite journal |last1=Ready |first1=J.S. |last2=Ferreira |first2=E.J.G. |last3=Kullander |first3=S.O. |year=2006 |title=Discus fishes: mitochondrial DNA evidence for a phylogeographic barrier in the Amazonian genus Symphysodon (Teleostei: Cichlidae) |journal=Fish Biology |volume=69 |pages=200–211 |doi=10.1111/j.1095-8649.2006.01232.x|bibcode=2006JFBio..69S.200R }}</ref> three species are recognized by FishBase:<ref name="fishbase">{{FishBase genus | genus = Symphysodon| month = April | year = 2013}}</ref> {| class="wikitable sortable" !Image !! Name !! Distribution |- |120px|| ''Symphysodon aequifasciatus'' Pellegrin, 1904 (blue discus or brown discus)||central Amazon Basin |- |thumb||| ''Symphysodon discus'' Heckel, 1840 (red discus or Heckel discus)|| Amazon Basin |- |120px|| ''Symphysodon tarzoo'' E. Lyons, 1959 (green discus)|| western Amazon Basin |- |}

==Taxonomy== thumb|''Symphysodon discus'' Discus are fish from the genus ''Symphysodon'', which currently includes the species ''S. aequifasciatus'', ''S. discus'' and ''S. tarzoo'', based on a taxonomic review published in 2006.<ref name=ready2006/><ref>{{Cite web |date=2006-11-28 |title=New Discus named Symphysodon tarzoo |url=http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=1145 |archive-url=https://web.archive.org/web/20090307162702/http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=1145 |archive-date=March 7, 2009 |access-date=15 August 2009 |website=Matt Clarke |publisher=practical fishkeeping}}</ref> A review published in 2007 largely came to the same result, but differed in nomenclature, as the species called ''S. tarzoo'' in the 2006 study was called ''S. aequifasciatus'' in the 2007 study, and ''S. aequifasciatus'' in 2006 was ''S. haraldi'' in 2007.<ref name="Bleher2007">{{Cite journal |last1=Bleher |first1=H. |last2=Stölting |first2=K.N. |last3=Salzburger |first3=W. |last4=Meyer |first4=A. |year=2007 |title=Revision of the genus Symphysodon Heckel, 1840 (Teleostei: Perciformes: Cichlidae) based on molecular and morphological characters |journal=Aqua |volume=12 |pages=133–174 |url=https://aquawildlife.com/images/artikler/Revision%20of%20the%20Genus%20Symphysodon.pdf }}</ref><ref>{{Cite web |date=2007-08-08 |title=Discus genus revised |url=http://www.practicalfishkeeping.co.uk/content.php?sid=1293 |archive-url=https://web.archive.org/web/20111106111632/http://www.practicalfishkeeping.co.uk/content.php?sid=1293 |archive-date=6 November 2011 |access-date=15 August 2009 |website=Matt Clarke |publisher=Practical Fishkeeping}}</ref> Further arguments have been made that ''S. tarzoo'' was not described in accordance with ICZN rules and thus should be considered invalid and replaced with ''S. haraldi'',<ref>Geerts, M. (2011): [http://www.cichlidae.com/article.php?id=433 On the name Symphysodon Discus Tarzoo.] ''The Cichlid Room Companion''</ref> currently considered a synonym of ''S. aequifasciatus'' by FishBase.

Other species and subspecies have been proposed, but morphometric data (unlike in ''Pterophyllum'', the freshwater angelfish) varies as much between individuals from one location as across the whole range of all discus fish species.{{citation needed|date=January 2017}} ''S. tarzoo'' was described in 1959 and applies to the red-spotted western population. ''S. aequifasciatus'' and ''S. discus'', meanwhile, seem to hybridise frequently in the wild or have diverged recently, as they lack mitochondrial DNA lineage sorting but differ in color pattern and have dissimilar chromosomal translocation patterns. ''S. discus'' occurs mainly in the Rio Negro. Whether ''S. haraldi'' is indeed distinct from ''S. aequifasciatus'' remains to be determined; if valid it is widespread but it might just be a color morph.{{citation needed|date=January 2017}}

thumb|Two captive variants (orange and solid turquoise) A molecular study in 2011 found five main groups, which generally matched previously recognized phenotypes. They recognized them as evolutionarily significant units and species.<ref name="Amado2011">{{Cite journal |last1=Amado |first1=M.V. |last2=Farias |first2=I.P. |last3=Hrbek |first3=T. |date=2011 |title=A Molecular Perspective on Systematics, Taxonomy and Classification Amazonian Discus Fishes of the Genus Symphysodon |journal=International Journal of Evolutionary Biology |volume=2011 |article-number=360654 |doi=10.4061/2011/360654 |pmc=3147135 |pmid=21811676 |doi-access=free }}</ref> Their assigning of scientific names to species differed to some extent from that used by earlier authors: Heckel (''S. discus''; Rio Negro, upper Uatumã, Nhamundá, Trombetas and Abacaxis), green (''S. tarzoo''; West Amazon drainages upriver from the Purus Arch, blue (''S.'' sp. 1; central Amazon from Purus Arch to the Meeting of Waters), brown (''S. aequifasciatus''; East Amazon downriver from Meeting of Waters), Xingu group (''S.'' sp. 2; Xingu and Tocantins).<ref name=Amado2011/> The Xingu group currently lacks a scientific name, but it is possible that the correct name for the blue is ''S. haraldi''.<ref name=Amado2011/> This taxonomy with four described valid species, ''S. discus'', ''S. tarzoo'', ''S. haraldi'' and ''S. aequifasciatus'', has been adopted by the Catalog of Fishes.<ref>{{Cite web |last1=Eschmeyer |first1=W.N. |last2=Fricke |first2=R. |last3=van der Laan |first3=R. |date=3 January 2017 |title=Symphysodon |url=http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp  |access-date=26 January 2017 |website=Catalog of Fishes |publisher=California Academy of Sciences}}</ref> Some hybridisation occurs (or has occurred) between the brown discus and neighbouring forms, but overall they maintain their separate evolutionary trajectories.<ref name=Amado2011/>

In addition to the wild discus, several captive variants achieved by selective breeding exist. Based on RAPD sequences, the captive variants popularly known as turquoise, pigeon, ghost, cobalt and solid red are derived from wild green, blue and brown discus (not Heckel discus).<ref name="Koh1999">{{Cite journal |last1=Koh |first1=T.L. |last2=Khoo |first2=G. |last3=Fan |first3=L.Q. |last4=Phang |first4=V.P.E. |year=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 |url=http://scholarbank.nus.edu.sg/handle/10635/102213 }}</ref>

==Description== thumb|alt=Red Turquoise Discus|Red turquoise discus Like cichlids from the genus ''Pterophyllum'' (angelfish), all ''Symphysodon'' species have a laterally compressed body shape. In contrast to ''Pterophyllum'', however, extended finnage is absent giving ''Symphysodon'' a more rounded shape. It is this body shape from which their common name, "discus", is derived.<ref>{{Cite web |last=Roberts |first=Jason |date=2022-03-09 |title=Discus Fish: The Complete Care, Species, & Breeding Guide |url=https://www.buildyouraquarium.com/discus-fish/ |access-date=2022-03-11 |website=Build Your Aquarium |language=en-US}}</ref> The sides of the fish are frequently patterned in shades of green, red, brown, and blue. Some of the more brightly marked variants are the result of selective breeding by aquarists and do not exist in the wild.<ref name=Koh1999/><ref name="Livengood">{{Cite web |last1=Livengood |first1=E.J. |last2=Ohs |first2=C.L. |last3=Chapman |first3=F.A. |year=2009 |title=Candidate Species for Florida Aquaculture: Discus Symphysodon spp., a Profitable but Challenging Species for Florida Aquaculture |url=https://edis.ifas.ufl.edu/fa166 |access-date=25 January 2017 |publisher=U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida}}</ref> Discus typically reach up to {{convert|12.3|-|15.2|cm|in|abbr=on}} in length,<ref name=fishbase/><ref name="Campton2008">{{Cite journal |last=Crampton |year=2008 |title=Ecology and life history of an Amazon floodplain cichlid: the discus fish Symphysodon (Perciformes: Cichlidae) |journal=Neotrop. Ichthyol. |volume=6 |issue=4 |pages=599–612 |doi=10.1590/S1679-62252008000400008 |doi-access=free}}</ref> but captives have been claimed to reach {{convert|9|in|cm|abbr=on|disp=flip}}.<ref>{{Cite web |title=Discus |url=http://www.seriouslyfish.com/species/symphysodon-aequifasciatus/ |access-date=25 January 2017 |publisher=Seriously Fish}}</ref> Adults generally weigh {{convert|150|-|250|g|oz|abbr=on}}.<ref name=Livengood/> Discus fish exhibit no sexual dimorphism when they are under about 4 inches in size, making it difficult to distinguish between males and females at a young age. Once they reach this size, the shape of their dorsal fins begins to change, with females retaining rounder dorsal fins and males developing more pointed ones. Other subtle indicators of sex include the overall size, as males are usually larger, and the thickness of their lips, with males often having thicker lips used for fighting. Despite these clues, none of these characteristics are guaranteed indicators of sex. The only definitive way to confirm the sex of discus fish is by observing spawning behavior, where a female lays eggs and a male swims over to fertilize them.{{citation needed|date=September 2024}}

==Behavior== thumb|Discus with two of its young nearby ''Symphysodon'' spp. are highly social, typically occurring in groups that may number many dozens of individuals, which is unique among cichlids of the Americas.<ref name=Campton2008/> When breeding, the pair moves away from the group, possibly to reduce the risk of cannibalism of the young.<ref name=Campton2008/> As with most cichlids, brood care is highly developed with both the parents caring for the young.<ref name="freshwatercentral">{{Cite web |last=freshwatercentral |date=2019-11-26 |title=The Complete Discus Fish Care Guide |url=https://freshwatercentral.com/discus-fish |access-date=2019-11-26 |website=Freshwater Central |language=en-US |archive-date=2022-06-30 |archive-url=https://web.archive.org/web/20220630095536/https://www.freshwatercentral.com/discus-fish }}</ref> Additionally, adult discus produce a secretion ("discus milk")<ref>{{cite book |doi=10.1016/S1546-5098(08)60098-9 |chapter=Prolactin (Fish Prolactin or Paralactin) and Growth Hormone |title=The Endocrine System |series=Fish Physiology |date=1969 |last1=Ball |first1=J.N. |volume=2 |pages=207–240 |isbn=978-0-12-350402-9 |quote-page=219 |quote=A special case is the discus fish, a cichlid Symphysodon discus, in which the skin of brooding fish hypertrophies and secretes mucus ('discus milk') which is eaten by the fry }}</ref> through their skin, on which the larvae live during their first 4 weeks.<ref name="Buckley">{{Cite journal |last1=Buckley |first1=J. |last2=Maunder |first2=R. J. |last3=Foey |first3=A. |last4=Pearce |first4=J. |last5=Val |first5=A. L. |last6=Sloman |first6=K. A. |year=2010 |title=Biparental mucus feeding: a unique example of parental care in an Amazonian cichlid |journal=J. Exp. Biol. |volume=213 |issue=22 |pages=3787–3795 |doi=10.1242/jeb.042929 |pmid=21037057 |doi-access=free|bibcode=2010JExpB.213.3787B |hdl=10026.1/12620 |hdl-access=free }}</ref> During the first two weeks, the parents stay near their young allowing them to feed easily. In the last 2 weeks, they swim away, resulting in the young being gradually "weaned off" and starting to fend for themselves.<ref name=Buckley/> Although rare in fish, more than 30 species of cichlids are known to feed their young with skin secretion to various extent,<ref name=Buckley/> including ''Pseudetroplus'' and ''Uaru'' species.<ref>{{Cite web |last=Leibel |first=W. |year=2010 |title=Cichlids of the Americas - Mouthbrooders |url=http://www.fishchannel.com/freshwater-aquariums/fish-breeding/mouthbrooders.aspx |access-date=22 January 2017 |publisher=FishChanel}}</ref> Sexual maturity is reached in a year.<ref name=Campton2008/>

{{Multiple image | total_width = 250 | image1 = Diskuslaich2.jpeg | image2 = Hatching of Discus eggs 2.jpg | footer = Eggs (left) and young feeding on parent's mucus (right) }}

Research <ref name="Sylvain">{{Cite journal |last1=Sylvain |first1=François-Étienne |last2=Derome |first2=Nicolas |year=2017 |title=Vertically and horizontally transmitted microbial symbionts shape the gut microbiota ontogenesis of a skin-mucus feeding discus fish progeny |journal=Scientific Reports |volume=7 |issue=1 |page=5263 |bibcode=2017NatSR...7.5263S |doi=10.1038/s41598-017-05662-w |pmc=5507859 |pmid=28701764}}</ref> has shown that, through this unique parental care behaviour (discus parents feeding their progeny with skin mucus), discus fish parents transmit key microorganisms to their fry. This parent-to-offspring transmission of important microorganisms might explain the high survival rate of discus fry raised with their parents, compared to the low survival rate of progeny raised artificially by fish breeders (e.g. on egg yolk, brine shrimp, or other replacement foods).<ref name=Sylvain/>

''Symphysodon'' spp. primarily feed on algae, other plant material, and detritus (periphyton), but also eat small invertebrates. Invertebrates can make up 38% of the stomach content in wild ''S. aequifasciatus'' during the high-water season, but this decreases during the low-water season, and year-round it is generally lower in the other species.<ref name=Campton2008/> Unlike more predatory cichlids, ''Symphysodon'' spp. have relatively long intestines typical of a herbivore or omnivore.<ref name=Campton2008/>

==Distribution and habitat== thumb|left|upright|alt=This is a map of distribution of Symphysodon (Discus fishes, in orange, in yellow Amazon River drainage basin).|A map of the range (orange shading) of ''Symphysodon''

''Symphysodon'' species inhabit the margins of floodplain lakes and rivers in the lowland Amazon basin,<ref name=Campton2008/> where they are part of the highly diverse Neotropical fish fauna. ''S. discus'' is restricted to blackwater habitats, but periodically these may experience brief floods of whitewater.<ref name=Bleher2007/> ''S. tarzoo'' is found in both black<ref name=Bleher2007/> and whitewater,<ref name=ready2006/> and ''S. aequifasciatus'' also occurs in clearwater.<ref name=Bleher2007/> Because of their preference for lentic habitats such as floodplains and flooded forests, whitewater inhabited by discus contains little suspended material (unlike main sections of whitewater rivers).<ref name=Amado2011/>

The three species of ''Symphysodon'' have different geographic distributions. ''S. aequifasciatus'' occurs in the East Amazon downriver from the Purus Arch and ''S. tarzoo'' in the West Amazon upriver from the Purus Arch.<ref name=ready2006/> In contrast, the distribution of ''S. discus'' appears to be limited to the lower reaches of the Rio Negro, upper Uatumã, Nhamundá, Trombetas, and Abacaxis Rivers.<ref name=ready2006/><ref name=Amado2011/>

The Nanay River in far western Amazonas is outside the native range; discus in this river were introduced from stock originating in the Tefé area by an aquarium exporter more than 30 years ago.<ref name=Bleher2007/>

A significant number of discus now live in fish farms in Southeast Asia. These discus go to home aquaria around the world.<ref>{{Cite web |date=28 July 2018 |title=Build Your Dream Discus Fish Aquarium - an Expert Guide |url=https://freshwatercentral.com/build-your-dream-discus-aquarium-an-expert-guide |access-date=13 May 2019 |archive-date=24 May 2022 |archive-url=https://web.archive.org/web/20220524084321/https://www.freshwatercentral.com/build-your-dream-discus-aquarium-an-expert-guide }}</ref>

== Water quality and pH requirements == Discus fish are highly sensitive to water chemistry, with their ideal potential of hydrogen (pH) requirements heavily dependent on whether the individuals are captive-bred or wild-caught. Historically, wild specimens are native to the soft, highly acidic blackwater tributaries of the Amazon basin, where pH values frequently range between 5.0 and 6.0.<ref name="Mattos2024">{{cite journal |last1=da Cruz Mattos |first1=D. |title=Effect of temperature on the embryonic and larvae development of discus fish Symphysodon aequifasciatus and time of first feeding |journal=Zygote |date=2024 |volume=32 |issue=2 |pages=145–152 |doi=10.1017/S096719942300054X}}</ref> In contrast, the vast majority of discus commercially available in the modern aquarium hobby are captive-bred strains. These domesticated fish exhibit significantly higher environmental plasticity and can be safely maintained in more neutral water chemistry, typically between 6.0 and 7.0 pH, though they can adapt to values as high as 7.5 provided the parameters remain stable.<ref name="Amesberger2019">{{cite journal |last1=Amesberger‐Freitag |first1=A. |last2=Tichy |first2=A. |last3=El‐Matbouli |first3=M. |last4=Lewisch |first4=E. |title=Hole‐in‐the‐head disease in discus fish, Symphysodon (Heckel, 1840): Is it a consequence of a dietary Ca/P imbalance? |journal=Journal of Fish Diseases |date=2019 |volume=42 |issue=8 |pages=1133–1142 |doi=10.1111/jfd.13023 |pmid=31190449}}</ref>

Water stability is considered far more critical to the long-term health of the fish than achieving a specific numerical target, as rapid pH fluctuations can induce severe physiological stress, compromise the immune system, or lead to acute alkalosis or acidosis. During the reproductive and early life stages, water parameters must be tightly regulated. Research into the embryonic and larval development of the blue discus (''Symphysodon aequifasciatus'') indicates that a stable pH range between 6.3 and 6.6 is optimal for minimizing developmental stress and preventing skeletal deformities during the incubation period.<ref name="Mattos2024" />

Additionally, chronic environmental stress or chemical imbalances—such as improper pH management combined with dietary calcium and phosphorus deficiencies—have been investigated as contributing environmental factors in the progression of systemic illnesses like Hole-in-the-head disease (HITH).<ref name="Amesberger2019" />

==Home aquarium== Discus are kept by fishkeepers in the home aquarium, where they are valued for their striking appearance.<ref>{{Cite web |title=Aquaworld Aquarium - Article - Discus - King Of The Aquarium |url=http://www.aquaworldaquarium.com/Articles/TonyGriffitts/Discus_KingOfTheAquarium.htm |access-date=2019-11-26 |website=www.aquaworldaquarium.com |archive-date=2023-02-05 |archive-url=https://web.archive.org/web/20230205200305/http://www.aquaworldaquarium.com/Articles/TonyGriffitts/Discus_KingOfTheAquarium.htm }}</ref> They are considered difficult to keep, due to strict requirements for water quality and the need to be kept in groups.<ref name="freshwatercentral" /> Breeders have selected for individuals with more adaptability to tap water conditions.<ref>{{Cite web |date=2016-06-13 |title=Discus: The whole truth and nothing but... |url=https://www.practicalfishkeeping.co.uk/features/discus-the-whole-truth-and-nothing-but-/ |access-date=2020-04-29 |website=Practical Fishkeeping}}</ref>

In home aquariums, discus live for an average of 10 years, but can live up to 15 years, and can grow up to 8 inches. Like many fish in the home aquarium, they will eat almost anything that fits within their mouth.<ref>{{Cite web |last=A-Z-Animals.com |title=Discus |url=https://a-z-animals.com/animals/discus/ |access-date=2019-11-26 |website=a-z-animals.com |language=en}}</ref> Due to their size, they often require a minimum {{convert|55|usgal|l|abbr=on}} – {{convert|75|usgal|l|abbr=on}} aquarium.<ref name="freshwatercentral" />

Each year the World Discus Competition takes place in Guangzhou, China.<ref>{{Cite web |title=AQUARAMA 2019 {{!}} Aquaria, Terraria, Garden & Pond {{!}} World Discus Competition |url=http://www.aquarama.com.cn/en/competitions/discus/ |access-date=2019-11-26 |website=www.aquarama.com.cn |archive-date=2023-09-01 |archive-url=https://web.archive.org/web/20230901035522/http://www.aquarama.com.cn/en/competitions/discus/ |url-status=dead }}</ref> The North American Discus Association focuses on both supporting hobbyists and helping to support wild discus.<ref>{{Cite web |title=North American Discus Association |url=http://www.discusnada.org/ |access-date=2019-11-26 |website=www.discusnada.org}}</ref>

== References == {{Reflist|30em}}

==External links== {{Commons category|Symphysodon}} {{Wikispecies|Symphysodon (Cichlidae)|Symphysodon}} *[https://web.archive.org/web/20020604050822/http://www.malaysiadiscus.com/home.shtml Discus Society Malaysia] *[http://www.fanatik-discus.fr/ Fanatik-Discus-International informations, pictures, videos about discus fish] *[https://www.discus-switch.com/ Discus Care Guide]

{{DEFAULTSORT:Discus (Fish)}} Category:Symphysodon Category:Fish of the Amazon basin Category:Cichlid fish of Brazil Category:Endemic fish of Brazil Category:Taxa named by Johann Jakob Heckel