View source for Goldfish

{{Short description|Freshwater fish common in aquariums}}
{{use mdy dates|date=December 2024}}
{{use American English|date=December 2024}}
{{About|the fish species|other uses|Goldfish (disambiguation)}}
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{{Speciesbox
| image = Gold fish1.jpg
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 13 November 2021">{{cite iucn |author=Huckstorf, V. |author2=Freyhof, J. |date=2013 |title=''Carassius auratus'' |volume=2013 |page=e.T166083A1110472 |doi=10.2305/IUCN.UK.2013-1.RLTS.T166083A1110472.en |access-date=13 November 2021}}</ref>
| taxon = Carassius auratus
| display_parents = 3
| authority = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])<ref>{{cite web |url=https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=508 |title=USGS-NAS, Non-indigenous Aquatic Species |access-date=2015-04-29}}</ref><ref name="fishbase">{{cite web|url=http://www.fishbase.org/Summary/speciesSummary.php?GenusName=Carassius&SpeciesName=auratus%20auratus |title=''Carassius auratus'' (Linnaeus, 1758) |publisher=Fishbase |access-date=2015-04-29}}</ref>
| synonyms = {{collapsible list|title=List of synonyms|
* ''Carassius discolor'' {{small|(Basilewsky, 1855)}}
* ''Carassius burgeri'' {{small|(Temminck & Schlegel, 1846)}}
* ''Carassius coeruleus'' {{small|(Basilewsky, 1855)}}
* ''Carassius encobia'' {{small|(Bonaparte, 1845)}}
* ''Carassius grandoculis'' {{small|(Temminck & Schlegel, 1846)}}
* ''Carassius pekinensis'' {{small|(Basilewsky, 1855)}}
* ''Cyprinus auratus'' {{small|(Linnaeus, 1758)}}
* ''Cyprinus gibelioides'' {{small|(Cantor, 1842)}}
* ''Cyprinus mauritianus'' {{small|(Bennett, 1832)}}
* ''Cyprinus chinensis'' {{small|(Gronow, 1854)}}
* ''Cyprinus maillardi'' {{small|(Guichenot)}}
* ''Cyprinus nigrescens'' {{small|(Günther, 1868)}}
* ''Cyprinus thoracatus'' {{small|(Valenciennes 1842)}}
* ''Neocarassius ventricosus'' {{small|(Castelnau, 1872)}}
}}
}}
{{Infobox Chinese
|c=金鱼
|l="gold fish"
|p=jīnyú
}}
[[File:Carassius auratus 197778318.jpg|thumb|Feral goldfish found in [[Essex County, Ontario]].]]
[[File:Carassius auratus.jpg|thumb|''Carassius auratus'' by [[Alexander Francis Lydon]].]]
The '''goldfish''' ('''''Carassius auratus''''') is a [[freshwater fish]] in the [[Family (biology)|family]] [[Cyprinidae]] of the [[Order (biology)|order]] [[Cypriniformes]]. It is commonly kept as a pet in indoor [[aquarium]]s, and is one of the most popular [[List of freshwater aquarium fish species|aquarium fish]]. Goldfish released into the wild have become an [[Invasive species|invasive pest]] in parts of North America and Australia.<ref>{{cite web |last=Helmore |first=Edward |url=https://www.theguardian.com/environment/2021/jul/12/goldfish-dumped-minnesota-lakes-threatening-ecosystems |title=Goldfish dumped in lakes grow to monstrous size, threatening ecosystems |work=[[The Guardian]] |date=12 July 2021 |url-status=live |archive-url=https://archive.today/20210713205042/https://www.theguardian.com/environment/2021/jul/12/goldfish-dumped-minnesota-lakes-threatening-ecosystems |archive-date=13 July 2021}}</ref><ref name="Lynch 2024 l054">{{cite web | last=Lynch | first=Jacqueline | title=Ozfish volunteers trap dumped pet goldfish from Vasse River amid concerns about water quality | website=ABC News | date=2024-04-23 | url=https://www.abc.net.au/news/2024-04-24/pest-goldfish-vasse-river-water-quality-concerns/103742088 | access-date=2024-04-27}}</ref>

Native to [[China]], the goldfish is a relatively small member of the [[carp]] family (which also includes the [[Prussian carp]] and the [[crucian carp]]). It was first [[selective breeding|selectively bred]] for color in [[imperial China]] more than 1,000 years ago, where several distinct [[breed]]s were developed. Goldfish breeds vary greatly in size, body shape, fin configuration, and coloration (various combinations of white, yellow, orange, red, brown, and black are known).

==History==
[[File:Goldfish in Fish Swimming Amid Falling Flowers by Liu Cai (cropped).jpg|thumb|Three goldfish from ''Fish Swimming Amid Falling Flowers'', a [[Song dynasty]] painting by Liu Cai ({{c.|1080–1120}})|alt=painting of many swimming fish, mostly in shades of tan]]
[[File:Carassius gibelio male 2021 G1.jpg|thumb|Male [[Prussian carp|Prussian Carp (''Carassius gibelio'')]] showing lots of [[Epithelium|epithelial]] [[tubercle]]s which appear at [[Spawn (biology)|spawning time]].]]
[[File:1856aquariumfresh.png|thumb|alt=A drawing in brown ink on an ocher background. A rectangular glass aquarium tank sits on a wooden stand with carved, curled legs, and contains two fish as well as plants with wavy grass-like leaves.|An aquarium of the 1850s of the type that contained Goldfish among other [[Coldwater fish|coldwater species]].]]
[[File:Ryukin goldfish plate.jpg|thumb|Ryukin goldfish, Plate XIX in ''Goldfish and Their Culture in Japan'', by Shinno

suke Matsubara.]]

Various species of [[carp]] (collectively known as [[Asian carp]]) have been bred and reared as [[Aquaculture|food fish]] for thousands of years in [[East Asia]]. Some of these normally gray or silver species have a tendency to produce [[Erythrism|red, orange]], or [[Xanthochromism| yellow color]] [[mutation]]s; this was first recorded in [[Imperial China]], during the [[Jin dynasty (266–420)]].<ref name="Ocean Park">{{cite web|url=http://www.oceanpark.com.hk/html/en/learning/facts/goldfish.html |title=Goldfish |publisher=Ocean Park |access-date=2009-11-16}}</ref><ref name=roots>{{cite book|last=Roots|first=Clive|title=Domestication|year=2007|publisher=Greenwood Press|location=Westport|isbn=978-0-313-33987-5|pages=20–21}}</ref>

During the [[Tang dynasty]] (AD 618–907), it was popular to raise carp in ornamental ponds and [[water garden]]s. A natural genetic mutation produced gold (actually yellowish orange) rather than silver coloration. People began to [[selective breeding|selectively breed]] the gold variety instead of the silver variety, keeping them in ponds or other bodies of water. On special occasions at which guests were expected, they would be moved to a much smaller container for display.<ref name="bristol" /><ref>[http://www.hagen.com/pdf/aquatic/Nutrafin_No4_English.pdf Nutrafin Aquatic News, Issue #4] {{Webarchive|url=https://web.archive.org/web/20070413152258/http://www.hagen.com/pdf/aquatic/Nutrafin_No4_English.pdf |date=2007-04-13 }}, 2004, Rolf C. Hagen, Inc. (USA) and Rolf C. Hagen Corp. (Montreal, Canada)</ref>

By the [[Song dynasty]] (AD 960–1279), the selective domestic breeding of goldfish was firmly established.<ref name=smartt>{{cite book|last=Smartt|first=Joseph|title=Goldfish varieties and genetics: A handbook for breeders|url=https://archive.org/details/goldfishvarietie00smar|url-access=limited|year=2001|publisher=Blackwell Science|location=Oxford|isbn=978-0-85238-265-3|page=[https://archive.org/details/goldfishvarietie00smar/page/n30 21]}}</ref> In 1162, the [[empress]] of the Song dynasty ordered the construction of a pond to collect the red and gold variety. By this time, people outside the imperial family were forbidden to keep goldfish of the gold (yellow) variety, [[Variations of yellow#Royal yellow|yellow being the imperial color]].<ref>{{Cite journal |last1=Chen |first1=Duo |last2=Zhang |first2=Qing |last3=Tang |first3=Weiqi |last4=Huang |first4=Zhen |last5=Wang |first5=Gang |last6=Wang |first6=Yongjun |last7=Shi |first7=Jiaxian |last8=Xu |first8=Huimin |last9=Lin |first9=Lianyu |last10=Li |first10=Zhen |last11=Chi |first11=Wenchao |last12=Huang |first12=Likun |last13=Xia |first13=Jing |last14=Zhang |first14=Xingtan |last15=Guo |first15=Lin |date=2020-11-24 |title=The evolutionary origin and domestication history of goldfish ( Carassius auratus ) |journal=Proceedings of the National Academy of Sciences |language=en |volume=117 |issue=47 |pages=29775–29785 |doi=10.1073/pnas.2005545117 |doi-access=free |issn=0027-8424 |pmc=7703540 |pmid=33139555|bibcode=2020PNAS..11729775C }}</ref>

During the [[Ming dynasty]] (1368–1644), goldfish also began to be raised indoors,<ref name=roots/> which permitted selection for mutations that would not be able to survive in ponds.<ref name="bristol"/> The first occurrence of -tailed goldfish was recorded in the Ming dynasty. In 1603, goldfish were introduced to [[Japan]].<ref name="bristol"/> In 1611, goldfish were introduced to [[Portugal]] and from there to other parts of [[Europe]].<ref name="bristol">{{cite web | url=http://www.bristol-aquarists.org.uk/goldfish/info/info.htm | title=Background information about goldfish | publisher=Bristol Aquarists' Society | access-date=2006-07-28}}</ref>

During the 1620s, goldfish were highly regarded in southern Europe because of their metallic scales, and symbolized good luck and fortune. It became a tradition for married men to give their wives a goldfish on their first anniversary, as a symbol for the prosperous years to come. This tradition quickly died, as goldfish became more available, losing their status. Goldfish were first introduced to [[North America]] around 1850 and quickly became popular in the [[United States]].<ref name=Brunner>{{cite book | last = Brunner | first = Bernd | title = The Ocean at Home | publisher = Princeton Architectural Press | year = 2003 | location = New York | isbn = 978-1-56898-502-2 | url-access = registration | url = https://archive.org/details/oceanathomeil00brun }}</ref><ref>{{cite book|last=Mulertt |first=Hugo |title=The Goldfish And Its Systematic Culture With A View To Profit |year=1883|url=https://archive.org/details/goldfishitssyste00mule |access-date=2009-07-07|publisher=Cincinnati [McDonald & Eick, print.] }}</ref>

==Biology==

===Taxonomy===
[[File:CarassiusCarassius8.JPG|thumb|[[Crucian carp|Crucian Carp (''Carassius carassius'')]], around 6 months old, 7 cm, from [[Haarlem|Haarlem, Netherlands]].]]
There has been considerable debate about the taxonomy of the goldfish. Previously, the goldfish was believed to be either a subspecies of the [[crucian carp]] (''Carassius carassius''), or of the [[Prussian carp]] (''Carassius gibelio'').<ref>{{cite web |last1=Laboratory |first1=NOAA Great Lakes Environmental Research |title=NOAA National Center for Research on Aquatic Invasive Species (NCRAIS) |url=https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?SpeciesID=508&Potential=N&Type=0 |website=nas.er.usgs.gov |access-date=16 December 2020}}</ref><ref name="Evolutionary origin ">{{cite journal|last=Komiyama |first=Tomoyoshi |author2=Hiroyuki Kobayashi |author3=Yoshio Tateno |author4=Hidetoshi Inoko |author5=Takashi Gojobori |author6=Kazuho Ikeo  |title=An evolutionary origin and selection process of goldfish |journal=Gene |date=February 2009 |volume=430 |issue=1–2|pmid=19027055 |pages=5–11 |doi=10.1016/j.gene.2008.10.019}}</ref><ref name="matsui">{{cite web|title=Common Gold Fish |work=Aquarticles |author=Les Pearce |url=http://www.aquarticles.com/articles/ponds/Pearce_Common_Goldfishhtml.htm |access-date=20 June 2006 |url-status=dead |archive-url=https://web.archive.org/web/20060528173947/http://www.aquarticles.com/articles/ponds/Pearce_Common_Goldfishhtml.htm |archive-date=28 May 2006 }}</ref> However, modern genetic sequencing has suggested otherwise, and that modern goldfish are domesticated varieties of ''C. auratus'' that are native to Southern China.<ref>{{cite journal|last=Wang |first=Shu-Yan |author2=Jing Luo |author3=Robert W. Murphy |author4=Shi-Fang Wu |author5=Chu-Ling Zhu |author6=Yun Gao |author7=Ya-Ping Zhang  |title=Origin of Chinese Goldfish and Sequential Loss of Genetic Diversity Accompanies New Breeds |journal=PLOS ONE |date=19 March 2013 |volume=430 |issue=3 |pages=e59571 |doi=10.1371/journal.pone.0059571|pmid=23527220 |pmc=3602300 |bibcode=2013PLoSO...859571W |doi-access=free }}</ref> ''C. auratus'' are differentiated from other ''Carassius'' species by several characteristics. ''C. auratus'' have a more pointed snout, while the snout of ''C. carassius'' is well rounded. ''C. gibelio'' often has a grayish/greenish color, while crucian carp are always golden bronze. Juvenile crucian carp have a black spot on the base of the tail, which disappears with age. In ''C. auratus'', this tail spot is never present. ''C. auratus'' have fewer than 31 scales along the lateral line, while crucian carp have 33 scales or more.

Goldfish can [[Hybrid (biology)|hybridize]] with some other ''[[Carassius]]'' species of carp. [[Koi]] and [[common carp]] may also interbreed with goldfish to produce sterile hybrids.

===Size===
Wild goldfish typically grow to between 4.7 inches (12 cm) and 8.7 inches (22 cm) but can reach 16 inches (41 cm).<ref>{{Cite book |last1=Page |first1=Lawrence M. |title=A field guide to freshwater fishes: North America north of Mexico |last2=Burr |first2=Brooks M. |date=1991 |publisher=Houghton Mifflin |others=National Audubon Society, National Wildlife Foundation, Roger Tory Peterson Institute |isbn=978-0-395-35307-3 |series=The Peterson field guide series |location=Boston}}</ref> The size of pet goldfish depends upon its breed.<ref>{{Cite web |title=Goldfish history, colour and finnage, diseases, how to keep them, and how to breed them |url=https://www.bristol-aquarists.org.uk/goldfish/info/info.htm |access-date=2024-02-05 |website=www.bristol-aquarists.org.uk}}</ref>

As of April 2008, the largest goldfish in the world was believed by the [[BBC]] to measure {{convert|19|in|cm}}, in the [[Netherlands]].<ref name=BBC17Apr2008>{{cite news|url=http://news.bbc.co.uk/1/hi/england/kent/7352909.stm |title=Giant goldfish 'simply amazing' |work=BBC News |date=17 April 2008 |access-date=17 July 2010}}</ref> At the time, a goldfish named "Goldie", kept as a pet in a tank in [[Folkestone]], England, was measured as {{convert|15|in|cm}} and over {{convert|2|lb|kg}}, and named as the second largest in the world behind the Netherlands fish.<ref name=BBC17Apr2008/> The secretary of the Federation of British Aquatic Societies (FBAS) stated of Goldie's size, "I would think there are probably a few bigger goldfish that people don't think of as record holders, perhaps in ornamental lakes".<ref name=BBC17Apr2008/> In July 2010, a goldfish measuring {{convert|16|in|cm}} and {{convert|5|lb|kg}} was caught in a pond in [[Poole]], England, thought to have been abandoned there after outgrowing a tank.<ref name=BBC15Jul2010>{{cite news|url=https://www.bbc.co.uk/news/uk-england-10649008 |title=Surrey schoolboy catches 5lb goldfish in Dorset lake |work=BBC News |date=15 July 2010 |access-date=17 July 2010}}</ref> On November 16, 2020, a {{convert|15|in|cm|adj=on}} goldfish weighing {{convert|9|lb}} was found in a {{cvt|16|acre|ha}} lake in [[Greenville, South Carolina]], while conducting a population survey of Oak Grove Lake.<ref>{{Cite web|title='Massive' goldfish weighing 9 pounds found in South Carolina lake|url=https://www.nbcnews.com/news/us-news/massive-goldfish-weighing-9-pounds-found-south-carolina-lake-n1250396|access-date=2021-05-17|website=NBC News|date=8 December 2020 |language=en}}</ref>

===Vision===
As a domestic fish, thus an easily accessible [[model organism]], goldfish have one of the most studied senses of [[vision in fishes]].<ref name = "Neumeyer">{{cite book |title=Sensory Processing in Aquatic Environments |url=https://archive.org/details/sensoryprocessin00bull |url-access=limited |last=Neumeyer |first=C.|editor=Collin, S.P. |editor2=Marshall, N.J. |chapter=Color Vision in Fishes and Its Neural Basis |year=2003|publisher=Springer-Verlag |location=New York |page=[https://archive.org/details/sensoryprocessin00bull/page/n253 223]|isbn=9780387955278}}</ref> Goldfish have four kinds of [[cone cell]]s, which are respectively sensitive to different colors: red, green, blue and [[ultraviolet]]. The ability to distinguish between four different [[primary color]]s classifies them as [[Tetrachromacy|tetrachromats]].<ref>{{cite book| last = Neumeyer| first = Christa | title = Das Farbensehen des Goldfisches: Eine verhaltensphysiologische Analyse|year = 1988| publisher = G. Thieme| isbn = 978-3137187011}}</ref>

===Hearing===
Goldfish have one of the most studied senses of [[Hearing#Hearing underwater|hearing in fish]].<ref>Ladich, F., & Fay, R. R. (2013). Auditory evoked potential audiometry in fish. Reviews in Fish Biology and Fisheries, 23(3), 317–364.</ref> They have two [[otolith]]s, permitting the detection of sound particle motion, and [[Weberian apparatus|Weberian ossicles]] connecting the [[swim bladder]] to the otoliths, facilitating the detection of [[sound pressure]].<ref>Fay, R. R., & Popper, A. N. (1974). Acoustic stimulation of the ear of the goldfish (Carassius auratus). Journal of Experimental Biology, 61(1), 243–260.</ref>

===Reproduction===
[[File:Goldfisheggs.JPG|thumb|Goldfish eggs.]]
[[File:Goldfishfry.JPG|thumb|Newly hatched goldfish fry (Ryukin).]]

Goldfish can only grow to [[sexual maturity]] with enough water and the right nutrition. Most goldfish [[Captive breeding|breed in captivity]], particularly in pond settings. Breeding usually happens after a significant temperature change, often in spring. Males chase [[gravid]] female goldfish (females carrying eggs), and prompt them to release their eggs by bumping and nudging them.

Goldfish, like all [[cyprinid]]s, are egg-layers. Their eggs are [[Adhesion|adhesive]] and attach to aquatic vegetation, typically dense plants such as ''[[Cabomba]]'' or ''[[Elodea]]'' or a spawning mop. The eggs hatch within 48 to 72 hours.

Within a week or so, the [[Spawn (biology)|fry]] begins to assume its final shape, although a year may pass before they develop a mature goldfish color; until then they are a metallic brown like their wild ancestors. In their first weeks of life, the fry grow quickly—an adaptation born of the high risk of getting devoured by the adult goldfish (or other fish and insects) in their environment.<ref>{{Cite web|url=http://thefishvet.com.au/pdf/Care_Gf_byRL.pdf|title=Goldfish (''Carassius auratus'')|first=Richmond|last=Loh|publisher=The Fish Vet.com|access-date=December 31, 2013|archive-date=January 27, 2014|archive-url=https://web.archive.org/web/20140127141326/http://thefishvet.com.au/pdf/Care_Gf_byRL.pdf|url-status=dead}}</ref>

Some highly [[Selective breeding|selectively bred]] goldfish can no longer breed naturally due to their altered shape. The artificial breeding method called "hand stripping" can assist in breeding, but can harm the fish if not done correctly.<ref>{{Cite web |date=1991 |title=Techniques for Taking and Fertilizing the Spawn of Fish |url=https://fisheries.tamu.edu/files/2013/09/SRAC-Publication-No.-426-Techniques-for-Taking-and-Fertilizing-the-Spawn-of-Fish.pdf |access-date=February 5, 2024}}</ref> In captivity, adults may also eat young that they encounter.

===Respiration===
Goldfish are able to [[self-preservation|survive]] short periods of entirely [[anoxic waters|anoxic conditions]]. Survival is shorter under higher temperatures, suggesting that this is a [[climatic adaptation|cold weather adaptation]]. Researchers speculate that this is specifically an adaptation to survival in [[frozen lake|frozen water bodies]] over winter.

Energy is obtained from [[liver]] [[glycogen]]. This process depends upon a [[pyruvate decarboxylase]] – the first known in [[vertebrate]]s.<ref name="Walker-1977">{{ Cite journal | url=http://cdnsciencepub.com/doi/10.1139/z77-170 | title=Walker, R. M., & Johansen, P. H. (1977). Anaerobic metabolism in goldfish (Carassius auratus). Canadian Journal of Zoology, 55(8), 1304–1311. doi:10.1139/z77-170  | year=1977 | doi=10.1139/z77-170 | pmid=902178 | last1=Walker | first1=R. M. | last2=Johansen | first2=P. H. | journal=Canadian Journal of Zoology | volume=55 | issue=8 | pages=1304–11 | url-access=subscription }}</ref><ref name="Fagernes-2017">{{ Cite journal | url= | title=Fagernes, C.E., Stensløkken, K., Røhr, Å.K. et al. Extreme anoxia tolerance in crucian carp and goldfish through neofunctionalization of duplicated genes creating a new ethanol-producing pyruvate decarboxylase pathway. Sci Rep 7, 7884 (2017). DOI: 10.1038/s41598-017-07385-4 | year=2017 | doi=10.1038/s41598-017-07385-4 | pmid=28801642 | last1=Fagernes | first1=C. E. | last2=Stensløkken | first2=K. O. | last3=Berenbrink | first3=M. | last4=Ellefsen | first4=S. | last5=Nilsson | first5=G. E. | journal=Scientific Reports | volume=7 | issue=1 | page=7884 | pmc=5554223 }}</ref>

===Salinity===
Although they are a freshwater fish, goldfish have been found in [[brackish water]] with a [[salinity]] of 17.<ref name="Tweedley-2017">{{ Cite journal | title=Tweedley, J.R., Hallett, C.S. & Beatty, S.J. Baseline survey of the fish fauna of a highly eutrophic estuary and evidence for its colonisation by Goldfish (Carassius auratus). Int Aquat Res 9, 259–270 (2017). DOI: 10.1007/s40071-017-0174-1 | journal=International Aquatic Research | date=September 2017 | volume=9 | issue=3 | pages=259–270 | doi=10.1007/s40071-017-0174-1 | s2cid=59358196 | last1=Tweedley | first1=James R. | last2=Hallett | first2=Chris S. | last3=Beatty | first3=Stephen J. | doi-access=free }}</ref>

==Behavior==

Goldfish are gregarious, displaying [[Swarm|schooling]] behavior, as well as displaying the same types of feeding behaviors.

Goldfish have learned behaviors, both as groups and as individuals, that stem from native carp behavior. They are a [[Generalist (ecology)|generalist]] species with varied feeding, breeding, and [[predator]] avoidance behaviors that contribute to their success. As fish, they can be described as "friendly" towards each other. Very rarely does a goldfish harm another goldfish, nor do the males harm the females during [[Biological reproduction|breeding]]. The only real threat that goldfish present to each other is competing for food. [[Common goldfish|Commons]], [[Comet (goldfish)|comets]], and other faster varieties can easily eat all the food during a feeding before  varieties can reach it. This can lead to stunted growth or possible [[starvation]] of fancier varieties when they are kept in a pond with their single-tailed brethren. As a result, care should be taken to combine only breeds with similar body type and swim characteristics.

==={{anchor|Intelligence}}Cognitive abilities===
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Goldfish have strong [[associative learning]] abilities, as well as [[Observational learning|social learning]] skills. In addition, their [[Visual perception|visual]] acuity allows them to [[Face perception|distinguish between individual humans]]. Owners may notice that fish react favorably to them (swimming to the front of the glass, swimming rapidly around the tank, and going to the surface mouthing for food) while hiding when other people approach the tank. Over time, goldfish learn to associate their owners and other humans with food, often "begging" for food whenever their owners approach.<ref name=":0">{{Cite web |last=Plumer |first=Brad |date=2016-06-09 |title=This is unsettling: fish can recognize human faces |url=https://www.vox.com/2016/6/9/11889508/fish-facial-recognition |access-date=2024-02-05 |website=Vox |language=en}}</ref>

Goldfish that have constant visual contact with humans also [[Habituation|stop considering them to be a threat]]. After being kept in a tank for several weeks, sometimes months, it becomes possible to feed a goldfish by hand without it shying away.

Goldfish have a [[Memory span|memory-span]] of at least three months and can distinguish between different shapes, colors, and sounds.<ref>Research by the School of Psychology at the [[University of Plymouth]] in 1994. Goldfish were trained to push a [[lever]] to earn a food reward; when the lever was fixed to work only for an hour a day, the fish soon learned to activate it at the correct time. See: {{Cite journal | date=July 1994 | title=Temporal discrimination learning of operant feeding in goldfish | journal=Journal of the Experimental Analysis of Behavior | volume=62 | issue=1 | pmid=16812735 | pmc=1334363 | pages=1–13 | last1 = Gee | first1 = P | last2 = Stephenson | first2 = D | last3 = Wright | first3 = DE | doi=10.1901/jeab.1994.62-1}}</ref><ref>The [[Discovery Channel]]'s show ''[[MythBusters]]'' tested the contemporary legend that goldfish only had a memory span of three seconds and were able to prove that goldfish had a longer memory span than commonly believed. The experiment involved training the fish to navigate a [[maze]]. It was evident that they were able to remember the correct path of the maze after more than a month. {{usurped|1=[https://web.archive.org/web/20070626043452/http://mythbustersresults.com/episode11  MythBuster Results: A goldfish’s memory lasts only three seconds]}}</ref> By using [[Negative reinforcement|positive reinforcement]], goldfish can be trained to recognize and to react to light signals of different colors<ref>Demonstrated in a 1994 public experiment at the [[Palais de la Découverte]] science museum. The experimental details and results are described in: {{Cite journal
 | date=April 1994
 | title=Poissons rouges: la mémoire dans l'eau
 | journal=Revue du Palais de la Découverte
 | volume=217
}}</ref> or to perform tricks.<ref>{{cite web |url= https://abcnews.go.com/story?id=4803721|title=Send Your Fish to School
|date=May 7, 2008|work=ABC News|access-date=December 28, 2012}}</ref> Fish respond to certain colors most evidently in relation to feeding.<ref name=":0" /> Fish learn to anticipate feedings provided they occur at around the same time every day.

==Classification==

===Western===
{{Main|List of goldfish varieties}}
As with many other examples of [[animal fancy|animal]], [[selective breeding]] of goldfish over centuries has produced several color variations, some of them far removed from the "[[Gold (color)|golden]]" color of the original fish. There are also different body shapes, and [[fin]] and [[eye]] configurations. Some extreme versions of the goldfish live only in [[aquarium]]s—they are much less hardy than varieties closer to the "wild" original. However, some variations are hardier, such as the Shubunkin. Currently, there are about 300 breeds recognized in China.<ref name=roots/> The vast majority of goldfish breeds today originated from China.<ref name=roots/> Some of the main varieties are:

{| class="wikitable"
|-
! colspan="2"|[[Common goldfish]]
! colspan="2"|[[Black Telescope]]
! colspan="2"|[[Bubble Eye]]
|-
| '''Common Goldfish''' come in a variety of colors including red, orange, "gold", white, black, and yellow ('lemon') goldfish.
| [[File:%E3%83%AF%E3%82%AD%E3%83%B320120701.JPG|120x120px]]
| The '''Black Telescope''' is a black-colored variant of [[Telescope (goldfish)|telescope goldfish]] that has a characteristic pair of protruding eyes. It is also referred to as popeye, moor, {{transliteration|ja|kuro-demekin}} in [[Japan]] and dragon-eye in [[China]].
| [[File:Black Moor Goldfish.jpg|120px]]
| The small '''Bubble Eye''' has no dorsal fin and upward pointing eyes accompanied by two large fluid-filled sacs.
| [[File:Bubble Eye goldfish.jpg|120px]]
|-
! colspan="2"|[[Celestial Eye]]
! colspan="2"|[[Comet (goldfish)|Comet]]
! colspan="2"|[[Fantail (goldfish)|Fantail]]
|-
| The '''Celestial eye goldfish''' or ''Choten gan'' has a double tail and a breed-defining pair of upturned, telescope eyes with pupils gazing skyward.
| [[File:Celestial eye goldfish.jpg|120px]]
| The '''comet''' or '''comet-tailed goldfish''' is a single-tailed variety in the [[United States]]. It is similar to the [[common goldfish]], except slightly smaller and slimmer, and is mainly distinguished by its long, deeply forked tail.
| [[File:Domesticcometgoldfish.jpg|120px]]
| The '''Fantail''' goldfish is the western form of the [[Ryukin]] and possesses an egg-shaped body, a high dorsal fin, a long [[wikt:quadruple|quadruple]] caudal fin, and no shoulder hump.
| [[File:Fan tailed goldfish.jpg|120px]]
|-
! colspan="2"|[[Lionhead (goldfish)|Lionhead]]
! colspan="2"|[[Oranda]]
! colspan="2"|[[Pearlscale]]
|-
| The '''lionhead''' has a hood. This [[fish]] is the [[wikt:Precursor|precursor]] to the [[ranchu]].
| [[File:LionheadGoldfishSideviewRodsan18b.jpg|120px]]
| The '''oranda''' is characterised by a prominent raspberry-like hood (also known as ''wen'' or head growth) that encases the whole head and some with the entire face, except for the eyes and mouth.
| [[File:OrangeOranda.jpg|120px]]
| The '''pearlscale''' or {{transliteration|ja|chinshurin}} in [[Japanese language|Japanese]], is spherical-bodied with finnage similar to the [[Fantail (goldfish)|fantail]] and [[Veiltail (goldfish)|veiltail]]. Its scales are protruded into white domes that resemble pearls.
| [[File:Goldfish Pearl Scale.jpg|120px]]
|-
! colspan="2"|[[Pompom (goldfish)|Pompom]]
! colspan="2"|[[Ryukin]]
! colspan="2"|[[Shubunkin]]
|-
| The '''Pompoms''', '''pompons''' or '''hanafusa''' have bundles of loose fleshy outgrowths between the nostril, called nasal boquettes, on each side of the head.
| [[File:Chocolate Oranda with Red pompoms 2.jpg|120px]]
| The '''ryukin''' has a short, deep body with a characteristic shoulder hump.
| [[File:Goldfish Ryukin.jpg|120px]]
| The [[Japan]]ese {{nihongo||朱文金|shubunkin}} (translated literally as "red brocade") have a single tail with [[wikt:nacreous|nacreous]] scales, and a pattern known as [[Calico (goldfish)|calico]].
| [[File:Clear shubunkin.jpg|120px]]
|-
! colspan="2"|[[Telescope (goldfish)|Telescope]]
! colspan="2"|[[Ranchu]]
! colspan="2"|[[Panda Telescope]]
|-
| The '''telescope''' is characterized by its protruding eyes. It is also known as the '''globe eye''' or '''dragon eye''' goldfish.
| [[File:DragonEye (bottom).jpg|120px]]
| The Japanese '''ranchu''' is hooded. The [[Japanese people|Japanese]] refer to it as the "king of goldfish".
| [[File:Goldfish Ranchu 2.jpg|120px]]
| The '''panda telescope''' is another colored variant of [[Telescope (goldfish)|telescope goldfish]].
| [[File:Pandamoor.jpg|120px]]
|-
! colspan="2"|[[Veiltail]]
! colspan="2"|[[Butterfly tail (goldfish)|Butterfly tail]]
! colspan="2"|[[Meteor goldfish]]
|-
| The '''veiltail''' is known for its extra-long, flowing double tail. Modern veiltail standards require little or no indentation of the trailing edges of the caudal fins, as in a wedding veil for a bride.
| [[File:Welon (ryba).JPG|120px]]
| The '''butterfly tail moor''' or '''butterfly telescope''' is of the telescope-eye lineage, with twin broad tails best viewed from above. The spread of the caudal fins resembles butterflies underwater.
| [[File:calico-butterfly-tail-demekin.png|120px]]
| The '''meteor goldfish''' is a strange-looking variety that has been developed by specialist breeders of  goldfish. It has no tail fin, hence its name.<ref name=Bristol>[http://www.bristol-aquarists.org.uk/goldfish/goldfish.htm Fancy Goldfish Varieties, Bristol Aquarists' Society, Bristol-Aquarists.org], retrieved on: June 20, 2007</ref><ref name="autogenerated2002">Andrews, Dr. Chris. "An Interpet Guide to Fancy Goldfish", Interpet Publishing, 2002 - {{ISBN|1-902389-64-6}}</ref>
| [[File:MeteorGoldfish.jpg|120px]]
|-
! colspan="2"|[[Lionchu]]
! colspan="2"|[[Egg-fish goldfish]]
! colspan="2"|[[Shukin]]
|-
| The '''Lionchu''' or '''lionhead-ranchu''' is a  goldfish that has resulted from crossbreeding [[Lionhead (goldfish)|lionheads]] and [[ranchu]]s.<ref name="Ponzio">{{cite web|url=http://www.goldfishpages.com/Articles/What%20is%20a%20Lionchu.pdf|archive-url=https://web.archive.org/web/20110725073933/http://www.goldfishpages.com/Articles/What%20is%20a%20Lionchu.pdf|url-status=dead|archive-date=2011-07-25|title="What is a Lionchu?" by Peter Ponzio, an article from the Goldfish Pages Website (Goldfish Society of America), date retrieved: 28 February 2013}}</ref><ref name="GFSA">{{cite web|url=http://www.goldfishpages.com/Articles/GFSA%20Ask%20the%20Judges%2C%20Ranchus.pdf|archive-url=https://web.archive.org/web/20110725074035/http://www.goldfishpages.com/Articles/GFSA%20Ask%20the%20Judges%2C%20Ranchus.pdf|url-status=dead|archive-date=2011-07-25|title="GFSA - Ask the Judges", an article about the Lionchu by Larry Christensen, Peter Ponzio, Scott Taylor, Tony Reynolds and John Parker, from the Goldfish Pages Website (Goldfish Society of America), date retrieved: 28 February 2013}}</ref>
| [[File:Goldfish Lionchu first orize winner.jpg|120px]]
| The '''egg-fish goldfish''' is a  goldfish that lacks a [[dorsal fin]] and has a pronounced egg-shaped body.<ref name=Andrews>Andrews, Chris, Dr. An Interpet Guide to Fancy Goldfish, Interpet Publishing, 2002. - {{ISBN|1-902389-64-6}}</ref><ref>{{cite web |url=http://www.hagen.com/usa/aquatic/more.cfm |title=Nutrafin Aquatic News, Issue #4, 2004, Rolf C. Hagen, Inc. (USA) and Rolf C. Hagen Corp. (Montreal, Canada) |publisher=Hagen.com |access-date=2011-11-19 |archive-url=https://web.archive.org/web/20111121090523/http://hagen.com/usa/aquatic/more.cfm |archive-date=2011-11-21 |url-status=dead }}</ref>
| [[File:Eggfish.jpg|120px]]
| The '''Shukin''' is a Ranchu-like goldfish developed from [[Ranchu]]s and [[Oranda]]s at the end of the 19th century in Japan.
| [[File:Shukin.jpg|120px]]
|-
! colspan="2"|[[Curled-gill goldfish]]
! colspan="2"|[[Tamasaba]]
! colspan="2"|[[Tosakin]]
|-
| The '''Curled-gill''' or '''Reversed-gill''' goldfish is another uncommon variety of  goldfish that has been developed by specialist [[enthusiasts]]. It owes its name to the out-turned appearance of its gill covers.<ref name="autogenerated2002"/><ref>Johnson, Dr. Erik L., D.V.M. and Richard E. Hess. Fancy Goldfish: A Complete Guide to Care and Collecting, Shambhala Publications, Inc., 2001 - {{ISBN|0-8348-0448-4}}</ref>
| [[File:Curled gill goldfish.jpg|120x150px]]
| The '''Tamasaba''' or [[Sabao]] is an uncommon Japanese variety of goldfish with a body shaped similar to the [[Ryukin]] and a very long, flowing, single tail that is similar to that of a [[comet goldfish]], hence its other name, [[comet (goldfish)|comet]]-tail ryukin.
| [[File:Tamasaba or Sabao.jpg|120x150px]]
| The '''Tosakin''' is a very distinctive breed of goldfish with a large tail fin that spreads out horizontally (like a fan) behind the fish, followed by the bottom tips folding behind its caudal fin. Though technically a divided tail, the two halves are attached at the center, forming a single fin.
| [[File:Tosakin.JPG|120x150px]]
|-
! colspan="2"|[[White Telescope]]
! colspan="2"|[[Jikin]]
! cosplan="2"|[[Telescope (goldfish)|Orange Telescope]]
|-
| The '''White telescope''' is a white variant of [[Telescope (goldfish)|telescope goldfish]] that has a white body and a characteristic pair of protruding eyes.
|
| The '''Jikin''' is a breed of '''[[wakin]]'''-like goldfish developed in Japan.
| [[File:弥富金魚ジキン.jpg|120x150px]]
| The Orange Telescope goldfish is a fascinating variant of the traditional goldfish, is renowned for its unique appearance and vibrant color. It’s especially distinguished by its protruding eyes and bright orange hue.
| [[File:DragonEye (bottom).jpg|120px]]
|}

===Chinese===
Chinese tradition classifies goldfish into four main types.<ref>{{Cite web |url=http://www.cnaquafish.com/html_news/QiYeXinWenTest-2-3.html |title=Evolution and Varieties of Goldfish |access-date=2015-08-02 |archive-url=https://web.archive.org/web/20160110164203/http://www.cnaquafish.com/html_news/QiYeXinWenTest-2-3.html |archive-date=2016-01-10 |url-status=dead }}</ref> These classifications are not commonly used in the West.
* Crucian (also called "grass") — Goldfish without anatomical features, similar to Crucian carp or [[grass carp]] except for their coloration. These include the common goldfish, comet goldfish and Shubunkin.
* Wen — Goldfish having a tail, e.g., fantails and veiltails. "Wen" is also the name of the characteristic headgrowth on such strains as oranda and lionhead.
* Dragon Eye — Goldfish having extended eyes, e.g., [[Black Moor (fish)|black moor]], [[bubble eye]], and [[telescope eye]]
* Egg — Goldfish having no dorsal fin, usually with an 'egg-shaped' body, e.g., [[Lionhead (goldfish)|lionhead]]. This group includes a bubble eye without a dorsal fin.

==Cultivation==
[[File:Pool Fisheries 01.jpg|thumb|Pool Fisheries, a goldfish farm in [[Lonoke, Arkansas]]]]
[[File:Goldfish Matisse.jpg|thumb|''[[Goldfish (Matisse)|Goldfish]]'' by [[Henri Matisse]], 1912]]

===In aquariums===
Like most species in the carp family, goldfish produce a large amount of waste both in their [[feces]] and through their [[gills]], releasing harmful [[chemical]]s into the water. Buildup of this waste to [[toxic]] levels can occur in a relatively short period of time, and can easily cause a goldfish's death. For common and comet varieties, each goldfish should have about {{convert|20|usgal}} of water. Smaller fantail goldfish should have about {{convert|10|usgal}} per goldfish. The water surface area determines how much [[oxygen]] diffuses and dissolves into the water. A general rule is have {{convert|1|sqft}}. Active [[aeration]] by way of a [[water pump]], [[filter (water)|filter]] or [[fountain]] effectively increases the surface area agitation.

The goldfish is classified as a [[coldwater fish]], and can live in unheated [[Aquarium|aquaria]] at a temperature comfortable for humans. However, rapid changes in temperature, for example in an office building in winter when the heat is turned off at night, can kill them, especially if the tank is small. Care must also be taken when adding water, as the new water may be of a different temperature. Temperatures under about {{convert|10|C|F}} are dangerous to fancy varieties, though commons and comets can survive slightly lower temperatures. Extremely high temperatures (over {{convert|30|C|F}}) can also harm goldfish. However, higher temperatures may help fight [[protozoa]]n infestations by accelerating the [[parasite]]'s life cycle—thus eliminating it more quickly. The optimum temperature for goldfish is between {{convert|20|and|22|C|F}}.<ref name="autogenerated1">{{cite web |url=http://www.mypets.net.au/flex/goldfish/528/1 |title=Goldfish |publisher=Mypets.net.au |access-date=2011-11-19 |archive-date=2010-07-28 |archive-url=https://web.archive.org/web/20100728043700/http://www.mypets.net.au/flex/goldfish/528/1 |url-status=dead }}</ref>

Like all fish, goldfish do not like to be petted. In fact, touching a goldfish can endanger its health, because it can cause the protective slime coat to be damaged or removed, exposing the fish's skin to infection from bacteria or water-borne parasites. However, goldfish respond to people by surfacing at feeding time, and can be trained or acclimated to taking pellets or flakes from human fingers. The reputation of goldfish dying quickly is often due to poor care.<ref>{{cite web|url=http://www.experiencefestival.com/goldfish |title=Goldfish |publisher=Experiencefestival.com |access-date=2011-11-19 |url-status=dead |archive-url=https://web.archive.org/web/20111212210227/http://www.experiencefestival.com/goldfish |archive-date=2011-12-12 }}</ref> The lifespan of goldfish in captivity can extend beyond 10 years.<ref>{{Cite news | url=https://www.bbc.com/news/29210991 | title=Goldfish has brain operation| work=BBC News| date=2014-09-15}}</ref>

If left in the dark for a period of time, goldfish gradually change color until they are almost gray.<ref name=":1">{{Cite web |date=2021-08-25 |title=Frequent question: Why do Goldfish Change Color? |url=https://www.nativefish.org/frequent-question-why-do-goldfish-change-color/ |access-date=2024-02-05 |website=Native Fish |language=en-US}}</ref> Goldfish produce pigment in response to light, similarly to how human skin becomes [[Sun tanning|tanned]] in the sun. Fish have cells called [[chromatophore]]s that produce pigments that reflect light and give the fish coloration. The color of a goldfish is determined by their diet, water quality, and exposure to light, along with age and health.<ref name=":1" />

Because goldfish eat live plants, their presence in a [[Aquascaping|planted aquarium]] can be problematic. Only a few aquarium plant species, such as ''[[Cryptocoryne]]'' and ''[[Anubias]]'', can survive around goldfish, but they require special attention so that they are not uprooted.<ref>{{Cite web |title=Planted Tanks for Goldfish |url=https://injaf.org/aquarium-fish/the-goldfish-section/planted-tanks-for-goldfish/ |access-date=2024-02-05 |website=INJAF |language=en-US}}</ref>

===In ponds===
[[File:Fish pond with filter Bury England 8 May 2023.jpg|left|thumb|Coldwater goldfish pond in [[Bury, Greater Manchester|Bury, England]]]]
[[File:Red Oranda goldfish in outdoor pond.jpg|thumb|Red Oranda (Wen) goldfish reared in a small outdoor pond with lilies]]
Goldfish are popular pond fish, since they are small, inexpensive, colorful, and very hardy. In an outdoor pond or [[water garden]], they may even survive for brief periods if [[ice]] forms on the surface, as long as there is enough [[oxygen]] remaining in the water and the pond does not freeze solid. Common, London and Bristol shubunkins, jikin, wakin, comet and some hardier fantail goldfish can be kept in a pond year-round in temperate and subtropical climates. Moor, veiltail, oranda and lionhead can be kept safely in outdoor ponds year-round only in more tropical climates and elsewhere only in summer months.

Compatible fish include [[Common rudd|rudd]], [[tench]], [[orfe]] and [[koi]], but the last require specialized care. [[Ramshorn snail]]s are helpful by eating any [[algae]] that grows in the pond. Without some form of [[animal population control]], goldfish ponds can easily become overstocked. Fish such as [[orfe]] consume goldfish eggs.

Ponds small and large are fine in warmer areas, though goldfish can "overheat" in small volumes of water in the summer in tropical climates.{{cn|date=October 2024}} In frosty climes, the depth should be at least {{convert|80|cm|in|sp=us}} to preclude freezing. During winter, goldfish become sluggish, stop eating and often stay on the bottom of the pond. This is normal; they become active again in the spring. Unless the pond is large enough to maintain its own ecosystem without interference from humans, a filter is important to clear waste and keep the pond clean. Plants are essential as they act as part of the filtration system, as well as a food source for the fish. Plants are further beneficial since they raise oxygen levels in the water.

Like their wild ancestors, common and comet goldfish as well as shubunkin can survive, and even thrive, in any climate that can support a pond. In general, when released into the wild, goldfish quickly take over the waterways as an [[invasive species]].<ref>{{Cite web |title=Goldfish |url=https://www.invasivespeciescentre.ca/invasive-species/meet-the-species/fish-and-invertebrates/goldfish/ |access-date=2024-02-05 |website=Invasive Species Centre |language=en-CA}}</ref><ref>{{Cite news |last=Yin |first=Steph |date=2016-09-22 |title=In the Wild, Goldfish Turn From Pet to Pest |url=https://www.nytimes.com/2016/09/23/science/discarded-goldfish-invasive-species.html |access-date=2024-02-05 |work=The New York Times |language=en-US |issn=0362-4331}}</ref>

===Feeding===
[[File:Aquarium - dried food2.jpg|thumb|right|alt=On a blue background, two large light red wafers at the upper left, a light gray compressed cube at the upper right, small brown pellets at the middle left, and, at the middle right and bottom, various yellow-green and red flakes|Various types of prepared fish food]]
{{See also|Fish food}}

In the wild, the diet of goldfish consists of [[crustacean]]s, [[insect]]s, and various [[plant]] matter. Like most fish, they are opportunistic feeders and do not [[Satiety|stop eating]] on their own accord. Overfeeding can be deleterious to their health, typically by blocking the [[intestines]]. This happens most often with selectively bred goldfish, which have a convoluted intestinal tract. When excess food is available, they produce more waste and [[feces]], partly due to incomplete [[protein]] digestion. Overfeeding can sometimes be diagnosed by observing feces trailing from the fish's [[cloaca]].

Goldfish-specific food has less protein and more [[carbohydrate]] than conventional fish food. Enthusiasts may supplement this diet with shelled [[pea]]s (with outer skins removed), [[Blanching (cooking)|blanched]] [[green leafy vegetable]]s, and [[Chironomidae|bloodworms]]. Young goldfish benefit from the addition of [[brine shrimp]] to their diet. As with all animals, goldfish preferences vary.

===For mosquito control===
Like some other well-known aquarium fish, such as the [[guppy]] and [[mosquitofish]], goldfish (and other carp) are frequently added to [[Stagnant (water)|stagnant]] bodies of water in an attempt to reduce [[mosquito]] populations, which spread the [[disease vector|vectors of diseases]] such as [[West Nile fever|West Nile virus]], [[malaria]], and [[Dengue fever|dengue]]. However, [[Introduced species|introducing]] goldfish has often had negative consequences for local [[ecosystem]]s,<ref>{{cite book|url=https://books.google.com/books?id=lNkwt3gX-2cC&q=goldfish+released+into+the+wild&pg=PA154|title=Biotechnology Deskbook|author1=William L. Arnold|author2=William L. Anderson|page=154|year=2001|publisher=Environmental Law Institute|isbn=978-1-58576-029-9}}</ref> and their efficacy as [[pest control]] has never been compared to those of native fishes.

===Market===
The market for live goldfish and other crucian carp usually imported from China was $1.2{{nbsp}}million in 2018. Some high quality varieties cost between $125 and $300.<ref>{{cite news |last=Selyukh |first=Alina |url=https://www.npr.org/2019/10/16/768553956/the-goldfish-tariff-fancy-pet-fish-among-the-stranger-casualties-of-the-trade-wa |title=The Goldfish Tariff: Fancy Pet Fish Among The Stranger Casualties Of The Trade War |work=[[NPR]] |date=2019-10-16 |access-date=2019-10-17 }}</ref>

== Welfare concerns ==
[[File:Goldfish Scooped Up.jpg|thumb|right|alt=View from above of children gathered around a pale blue rectangular tub filled with many small orange fish swimming in water. A girl at the top of the scene leans over the tub, with a pink scoop in her right hand and a white bowl in her left hand.|The Japanese game of [[goldfish scooping]]]]
[[wikt:fishbowl|Fishbowls]] are detrimental to the health of goldfish and are prohibited by [[animal welfare]] legislation in several municipalities.<ref name="The Times">{{cite news | url=http://www.timesonline.co.uk/article/0,,13509-1844070,00.html | archive-url=https://archive.today/20060105045820/http://www.timesonline.co.uk/article/0,,13509-1844070,00.html | url-status=dead | archive-date=January 5, 2006 | title=Rome bans goldfish bowls, orders dog owners on walks&nbsp;– World&nbsp;– Times Online | access-date=2006-07-21 | location=London | work=The Times | first1=Sam | last1=Knight | date=2005-10-26}}</ref><ref name="Council bans goldfish bowls">{{cite news | url=http://www.abc.net.au/news/2004-07-24/council-bans-goldfish-bowls/2014352 | title=Council bans goldfish bowls | access-date=2015-04-21 | work=ABC Australian Broadcast Corporation | date=2004-07-23}}</ref> The practice of using bowls as permanent fish housing originated from a misunderstanding of Chinese "display" vessels: goldfish which were normally housed in ponds were, on occasion, temporarily displayed in smaller containers to be better admired by guests.<ref name="bristol" />

Goldfish kept in bowls or "mini-aquariums" suffer from death, disease, and [[Stunted growth|stunting]], due primarily to the low oxygen and very high [[ammonia]]/[[nitrite]] levels inherent in such an environment.<ref>{{cite web|url=http://goldfishcareguide.com/2008/03/05/5-reasons-not-to-use-goldfish-bowls/|title=5 reasons not to use goldfish bowls|access-date=2009-02-01|date=2008-03-05|publisher=Goldfish Care Guide|archive-url=https://web.archive.org/web/20180525162142/http://goldfishcareguide.com/2008/03/05/5-reasons-not-to-use-goldfish-bowls/|archive-date=2018-05-25|url-status=dead}}</ref> In comparison to other common aquarium fish, goldfish have high oxygen needs and produce a large amount of waste due to the fact they lack a stomach;<ref>{{cite web|url= https://injaf.org/aquarium-fish/the-goldfish-section/goldfish-and-their-diet/ | title=goldie
|accessdate=1 February 2022|work=goldfishsection}}</ref> therefore they require a substantial volume of well-filtered water to thrive. In addition, all goldfish varieties have the potential to reach {{convert|5|in}} in total length, with single-tailed breeds often exceeding {{convert|1|ft}}. Single-tailed varieties include common and comet goldfish.

In many countries, [[carnival]] and [[fair]] operators commonly give goldfish away in [[plastic]] bags as [[prize]]s. In late 2005 [[Rome]] banned the use of goldfish and other animals as carnival prizes. Rome has also banned the use of "goldfish bowls", on animal cruelty grounds,<ref name="The Times"/> as well as [[Monza]], Italy, in 2004.<ref name="Council bans goldfish bowls"/> In the [[United Kingdom]], the government proposed banning this practice as part of its Animal Welfare Bill,<ref>{{cite web|url=http://www.defra.gov.uk/animalh/welfare/bill/index.htm |title=Defra, UK&nbsp;– Animal Health and Welfare&nbsp;– Animal Welfare&nbsp;– Animal Welfare Bill |access-date=2006-07-21 |url-status=dead |archive-url=https://web.archive.org/web/20060820191520/http://www.defra.gov.uk/animalh/welfare/bill/index.htm |archive-date=2006-08-20 }}</ref><ref>
[[BBC News Online]] - [http://news.bbc.co.uk/1/hi/magazine/3893889.stm Goldfish are no longer to be given as prizes]</ref> though this has since been amended to only prevent goldfish being given as prizes to unaccompanied minors.<ref>
[[BBC News Online]] - [http://news.bbc.co.uk/1/hi/uk_politics/4174457.stm  Ban on goldfish prizes 'dropped']</ref>

In [[Japan]], during summer festivals and religious holidays ([[ennichi]]), a traditional game called [[goldfish scooping]] is played, in which a player scoops goldfish from a basin with a special scooper. Sometimes [[bouncy ball]]s are substituted for goldfish.

Although edible and closely related to some fairly widely eaten species, goldfish are rarely eaten. A fad among [[United States|American]] college students for many years was [[Goldfish swallowing|swallowing goldfish]] as a [[stunt]] and as a [[Fraternities and sororities|fraternity]] initiation process. The first recorded instance was in 1939 at [[Harvard University]].<ref>{{cite web|url=http://library.thinkquest.org/3205/SwalG.html |title=Swallowing Goldfish |access-date=2006-07-21 |url-status=dead |archive-url=https://web.archive.org/web/20060618034748/http://library.thinkquest.org/3205/SwalG.html |archive-date=2006-06-18 }}</ref> The practice gradually fell out of popularity over the course of several decades and is rarely practiced today.

Some animal advocates have called for boycotts of goldfish purchases, citing industrial farming and low survival rates of the fish.<ref>{{cite web|url=https://greenprophet.com/2012/03/goldfish-nowruz-iranian-new-year/|title=5 Million Goldfish Die for Nowruz – the Iranian New Year|first=Tafline|last=Laylin|website=Green Prophet|date=2012-03-19}}</ref><ref>{{cite web|url=https://globalvoices.org/2012/03/16/iran-a-nowruz-new-year-without-goldfish/|title=Iran: A Nowruz New Year Without Goldfish? · Global Voices|date=16 March 2012}}</ref>

== In popular culture ==
{{seealso|The Golden-Headed Fish|The Tale of the Fisherman and the Fish|The Gold-Children}}
[[File:Nowrooz-Yousef_Abdinejad-50x70cm-oil_on_canvas.jpg|thumb|Goldfish is one of the items used among the ''Haft-sin'' symbols of ''Nowruz.'' These are related to elements of Fire, Earth, Air, Water, and the three life forms of Humans, Animals and Plants.]]
In [[China|Chinese]] history, goldfish was seen "as a symbol of luck and fortune". Moreover, only members of the [[Song dynasty]] could own goldfish.<ref>{{Cite web |last=Gulliver |first=Katrina |date=2012-11-01 |title=The Great Goldfish Invasion: How an Exotic Carp Took Over America |url=https://www.theatlantic.com/national/archive/2012/11/the-great-goldfish-invasion-how-an-exotic-carp-took-over-america/264420/ |access-date=2024-02-05 |website=The Atlantic |language=en}}</ref> In [[Iran]] and among the international [[Iranian diaspora]], goldfish is a traditional part of [[Nowruz#Haft Sīn|Nowruz]] celebrations. Goldfish are usually placed on ''[[Haft-sin]]'' tables as a symbol of progress.<ref>{{Cite web|title=Nowruz: Persian New Year's Table Celebrates Spring Deliciously|url=https://www.npr.org/sections/thesalt/2016/03/20/471174857/nowruz-persian-new-years-table-celebrates-spring-deliciously|access-date=2021-03-24|website=NPR.org|date=20 March 2016 |language=en|last1=Fulton |first1=April |last2=Ardalan |first2=Davar }}</ref>

==See also==
* [[Aquaculture]]
* [[List of goldfish varieties]]
* [[Henri Matisse and goldfish]]

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

==External links==
{{Commons}}
* {{ITIS |id=163350 |taxon=Carassius auratus |access-date=5 October 2004}}
* {{FishBase_species alt|ID=271|taxon=Carassius auratus auratus|year=2004|month=September}}
* [https://goldfishmania.com/goldfish-types/ Goldfish Types] {{Webarchive|url=https://web.archive.org/web/20221207015905/https://goldfishmania.com/goldfish-types/ |date=2022-12-07 }}&nbsp;— Description of 50 plus varieties of goldfish with pictures
* [http://www.bristol-aquarists.org.uk/goldfish/goldfish.htm Bristol Aquarists' Society: Goldfish]&nbsp;— Photographs and descriptions of the different goldfish varieties

{{Goldfish breeds}}
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{{Taxonbar|from=Q123141}}
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[[Category:Goldfish| ]]
[[Category:Fish described in 1758]]
[[Category:Taxa named by Carl Linnaeus]]
[[Category:Carassius]]
[[Category:Fishkeeping]]
[[Category:Fish of China]]
[[Category:Freshwater fish of New Zealand]]