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The '''goldfish''', ''Carassius auratus'', was one of the earliest [[fish]] to be [[domestication|domesticated]], and is still one of the most commonly kept [[List of freshwater aquarium fish species|aquarium fish]] and [[water garden]] fish. A relatively small member of the [[Cyprinidae|carp]] family, the goldfish is a domesticated version of a dark-gray/brown carp native to [[East Asia]]. It was first domesticated in [[China]]<ref name="bristol">{{cite web | url=http://www.bristol-aquarists.org.uk/goldfish/info/info.htm | title=Background information about goldfish | accessdate=2006-07-28}}</ref> and introduced to [[Europe]] in the late 17th century.
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The '''goldfish''', ''Carassius auratus'', was one of the earliest [[fish]] to be [[domestication|domesticated]], and is still one of the most commonly kept aquarium fish and water garden fish. A relatively small member of the [[Cyprinidae|carp]] family, the goldfish is a domesticated version of a dark-gray/brown carp native to East Asia. It was first domesticated in China<ref name="bristol">{{cite web | url=http://www.bristol-aquarists.org.uk/goldfish/info/info.htm | title=Background information about goldfish | accessdate=2006-07-28}}</ref> and introduced to [[Europe]] in the late 17th century.
   
 
Goldfish may grow to a maximum length of 23 inches (59&nbsp;cm) and a maximum weight of 9.9&nbsp;pounds (4.5&nbsp;kg), although this is rare; few goldfish reach even half this size. The oldest recorded goldfish lived to 49 years,<ref>[http://webspace.ship.edu/gspaul/animal%20behavior/goldfish%20foraging/intro_goldfish_foraging.html], [http://store.koistation.com/goldfish.html]</ref> but most household goldfish generally live only six to eight years, due to being kept in bowls.<ref>{{cite web | url=http://www.theprofishionals.com.au/NewFiles/autumn2001.pdf | title=Fishtalk from The Profishionals, Autumn 2001 (PDF) | accessdate=2006-07-21}}</ref> A group of goldfish is known as a troubling.<ref>{{cite web | url=http://www.sandiegozoo.org/animalbytes/got_questions_groups_list.html | title=San Diego Zoo's Got Questions? Animal Group Names | accessdate=2007-02-04}}</ref>
 
Goldfish may grow to a maximum length of 23 inches (59&nbsp;cm) and a maximum weight of 9.9&nbsp;pounds (4.5&nbsp;kg), although this is rare; few goldfish reach even half this size. The oldest recorded goldfish lived to 49 years,<ref>[http://webspace.ship.edu/gspaul/animal%20behavior/goldfish%20foraging/intro_goldfish_foraging.html], [http://store.koistation.com/goldfish.html]</ref> but most household goldfish generally live only six to eight years, due to being kept in bowls.<ref>{{cite web | url=http://www.theprofishionals.com.au/NewFiles/autumn2001.pdf | title=Fishtalk from The Profishionals, Autumn 2001 (PDF) | accessdate=2006-07-21}}</ref> A group of goldfish is known as a troubling.<ref>{{cite web | url=http://www.sandiegozoo.org/animalbytes/got_questions_groups_list.html | title=San Diego Zoo's Got Questions? Animal Group Names | accessdate=2007-02-04}}</ref>
 
==History==
 
 
During the [[Tang Dynasty]], it was popular to dam carp in ponds. As the result of a [[dominance relationship|dominant]] genetic [[mutation]], one of these carp displayed gold (actually yellowish orange) rather than silver coloration. People began to breed the gold variety instead of the silver variety, and began to display them in small containers. The fish were not kept in the containers permanently, but would be kept in a larger body of water, such as a pond, and only for special occasions at which guests were expected would they be moved to the much smaller container.<ref name="bristol" />
 
 
In 1162, the [[Empress]] of the [[Song Dynasty]] ordered the construction of a pond to collect the red and gold variety of those carp. By this time, people outside the imperial family were forbidden to keep goldfish of the gold (yellow) variety, yellow being the imperial color. This probably is the reason why there are more orange goldfish than yellow goldfish, even though the latter are genetically easier to breed.<ref>{{cite web | url=http://www.wetpetz.com/goldfish.htm | title=goldfish | accessdate=2006-07-21}}</ref>
 
 
The occurrence of other colors was first recorded in 1276. The first occurrence of fancy tailed goldfish was recorded in the [[Ming dynasty]]. In 1502, goldfish were introduced to [[Japan]], where the [[Ryukin]] and Tosakin varieties were developed.
 
 
In 1854, goldfish were introduced to [[Portugal]] and from there to other parts of Europe. 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 | date= 2003 | location = New York | isbn = 1-56898-502-9 }}</ref>
 
   
 
==Description==
 
==Description==
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==Varieties==
 
==Varieties==
   
[[Selective breeding]] over centuries has produced several color variations, some of them far removed from the "[[gold]]en" color of the originally domesticated fish. Goldfish may also lose their "golden" color, or rather any goldfish color, by being kept in a dark room, this causes the scales to turn white. There are also different body shapes, [[fin]] and [[eye]] configurations. Some extreme versions of the goldfish need to be kept in an [[aquarium]] &mdash; they are much less hardy than varieties closer to the "wild" original. However, some variations are hardier, such as the [[Shubunkin]].
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[[Selective breeding]] over centuries has produced several color variations, some of them far removed from the "golden" color of the originally domesticated fish. Goldfish may also lose their "golden" color, or rather any goldfish color, by being kept in a dark room, this causes the scales to turn white. There are also different body shapes, [[fin]] and [[eye]] configurations. Some extreme versions of the goldfish need to be kept in an aquarium &mdash; they are much less hardy than varieties closer to the "wild" original. However, some variations are hardier, such as the [[Shubunkin]].
[[Image:Carassus carassus gold.JPG|thumb|right|220px|A [[crucian carp]] carrying a [[mutation]] for yellow [[pigment]]. Some of the first goldfish may have looked like this.]]
 
[[Image:Comet-pond.jpg|thumb|right|220px|A comet goldfish. One of the most common varieties.]]
 
The main goldfish varieties are:
 
*[[Black Moor]]
 
*[[Bubble eye]]
 
*[[Butterfly tail (goldfish)|Butterfly tail]]
 
*[[Calico (goldfish)|Calico]]
 
*[[Celestial eye]]
 
*[[Comet (goldfish)|Comet]]
 
*[[Common goldfish|Common]]
 
*[[Fantail (goldfish)|Fantail]]
 
*[[Lionchu]]
 
*[[Lionhead (goldfish)|Lionhead]]
 
*[[Oranda]]
 
*[[Panda Moor]]
 
*[[Pearlscale]]
 
*[[Pompom (goldfish)|Pompom]]
 
*[[Ranchu]]
 
*[[Ryukin]]
 
*[[Shubunkin]]
 
*[[Telescope eye]]
 
*[[Veiltail]]
 
 
===Chinese classification===
 
In Chinese goldfish keeping, goldfish are classified into 4 main types, which are not commonly used in the west.
 
 
*Dragon eye - Goldfish with extended eyes, e.g. [[Black Moor]], [[Bubble Eye]], and [[telescope eye]]
 
*Egg - goldfish without a dorsal fin. e.g. [[Lionhead (goldfish)|lionhead]] (note that a bubble eye without a dorsal fin belongs to this group)
 
*Wen - goldfish with dorsal fin and a fancy tail. e.g. [[veiltail]] ("wen" is also the name of the characteristic headgrowth on such strains as oranda and lionhead)
 
*Ce (may also be called "grass") - goldfish without anything fancy. This is the type that is usually used in Japanese carnivals, especially for "goldfish scoops".
 
*Jikin and wakin - goldfish with double tails, but with the body shapes of comets.
 
[[Image:Calico Goldfish.jpg|thumb|right|220px|A school of fancy goldfish.]]
 
 
===Rare varieties===
 
* [[Tosakin]] or [[Tosakin|curly fantail]] or [[Tosakin|peacock tail]] goldfish
 
* [[Tamasaba]] or [[sabao]]
 
* [[Meteor goldfish]]
 
* [[Egg-fish goldfish]]
 
* [[Curled-gill goldfish]] or [[curled-gill goldfish|reversed-gill goldfish]]
 
 
===New varieties===
 
* '''Azuma nishiki''' - a [[nacre]]ous-colored [[oranda]]
 
* '''Muse''' - a cross between a tosakin and an azuma nishiki with black eyes and white translucent scales
 
* '''Aurora''' - a cross between a [[shubunkin]] and an azuma nishiki or between a calico [[jikin]] and a tosakin
 
* '''Willow''' - a long and willowy telescope-eyed [[comet]] or shubunkin
 
* '''Dragon eye ranchu''' or '''squid ranchu''' - a telescope eyed [[ranchu]] variety
 
* '''[[Ranchu|Singachu]]''' or '''sakura singachu''' - a ranchu variant
 
 
===Revived varieties===
 
* [[Ranchu|Osaka ranchu]] - a ranchu relative
 
* [[Ranchu|Izumo nankin]] - a ranchu-like variety
 
 
==In ponds==
 
[[Image:Pfish.jpg|left|200px|thumb|Goldfish pond]]
 
Goldfish are popular pond fish, since they are small, inexpensive, colourful, and very hardy. In a pond, they may even survive if brief periods of [[ice]] form on the surface, as long as there is enough [[oxygen]] remaining in the water and the pond does not freeze solid.
 
 
Common goldfish, London and Bristol shubunkins, jikin, wakin, comet and sometimes fantail can be kept in a pond all year round in temperate and subtropical climates. Moor, veiltail, oranda and lionhead are only safe in the summer.
 
 
Small to large ponds are fine though the depth should be at least 80 cm (30 in) to avoid freezing. During winter, goldfish will become sluggish, stop eating, and often stay on the bottom of the tank. This is completely normal; they will become active again in the spring. 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 furthermore beneficial since they raise oxygen levels in the water.
 
 
Compatible fish include [[rudd]], [[tench]], [[orfe]] and [[koi]], but the latter will require specialized care. [[Ramshorn snail]]s are helpful by eating any algae that grows in the pond. It is of great importance to introduce fish that will consume excess goldfish eggs in the pond, such as orfe. Without some form of population control, goldfish ponds can easily become overstocked. Koi may also interbreed to produce a sterile new fish.
 
<br clear=both />
 
 
==In aquaria==
 
The goldfish is usually classified as a [[coldwater fish]], and it can live in an unheated aquarium. Like most carp, goldfish produce a large amount of waste both in their feces and through their gills, releasing harmful [[chemical]]s into the water. This also happens because goldfish, like other cyprinids, lack a [[stomach]] and only have an intestinal tract, and thus cannot digest an excess of proteins, unlike most [[tropical fish]].{{Fact|date=February 2007}} Build-up of this waste to [[toxic]] levels can occur in a relatively short period of time, which is often the cause of a fish's sudden death. It may be the amount of ''water surface area'', not the water volume, that decides how many goldfish may live in a container, because this determines how much oxygen diffuses and dissolves from the air into the water; one square foot of water surface area for every inch of goldfish length (370 cm²/cm). If the water is being further aerated by way of [[water pump]], [[filter (water)|filter]] or [[fountain]], more goldfish may be kept in the container.<REF>http://www.livefish.com.au/index.php?main_page=product_info&products_id=647</REF>
 
 
[[Image:Goldfishies.jpg|right|200px|thumb|Goldfish aquarium]]
 
Goldfish may be coldwater fish, but this does not mean they can tolerate rapid changes in temperature. The sudden shift in temperature that comes at night, for example in an office building where a goldfish might be kept in a small office tank, could kill them, especially in winter. Temperatures under about 10 °C (50 °F) are dangerous to goldfish. Conversely, temperatures over 25 °C (77 °F) can be extremely damaging for goldfish (this is the main reason why they shouldn't be kept in tropical tanks).<Ref>http://www.mypets.net.au/flex/goldfish/528/1</ref>
 
 
The popular image of a goldfish in a small [[wiktionary:fishbowl|fishbowl]] is an enduring one. Unfortunately, the risk of stunting, deoxygenation, ammonia/nitrite poisoning caused by such a small environment means that this is hardly a suitable home for any species of fish, and some countries have banned the sale of bowls of that type under animal rights legislation. <ref name=bowlban/>
 
 
The supposed reputation of goldfish dying quickly is often due to poor care amongst uninformed buyers looking for a cheap pet.<ref>http://www.experiencefestival.com/goldfish</ref> The true lifespan of a well-cared-for goldfish in captivity can extend beyond 10 years.
 
 
Goldfish, like all fish that are kept as pets, do not like to be petted. In fact, touching a goldfish can be quite dangerous to its health, as it can cause the protective slime coat to be damaged or removed, which opens the fish’s skin up to infection from bacteria or parasites in the water.
 
 
Fancy goldfish are unlikely to survive for long in the wild as they are handicapped by their bright fin colors; however it is not beyond the bounds of possibility that such a fish, especially the more hardy varieties such as the Shubunkin, could survive long enough to breed with its wild cousins. Common and comet goldfish can survive, and even thrive, in any climate in which a pond for them can be created. Introduction of wild goldfish can cause problems for native species. Within three breeding generations, the vast majority of the goldfish spawn will have reverted to their natural olive color. Since they are carp, goldfish are also capable of breeding with certain other species of carp and creating hybrid species.<REF>http://www.newworldencyclopedia.org/entry/Goldfish</ref>
 
 
Research by Dr. Yoshiichi Matsui, a professor of fish culture at Kinki University in Japan, suggests that there are subtle differences which demonstrate that while the [[crucian carp]] is the ancestor of the goldfish, they have sufficiently [[Divergent evolution|diverged]] to be considered separate species.<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 | accessdate=20 June | accessyear=2006}}</ref>
 
 
If left in the dark for a period of time, a goldfish will turn almost white. Goldfish have pigment production in response to light, which is almost like our tanning in the sun. Fish have cells called [[chromatophore]]s that produce pigments which reflects light, and gives coloration. The color of a goldfish is determined by which pigments are in the cells, how many pigments molecules there are, and whether the pigment is grouped inside the cell or is spaced throughout the cytoplasm. So if a goldfish is kept in the dark it will appear lighter in the morning, and over a long period of time will lose its color.{{Fact|date=July 2007}}
 
   
 
==Feeding==
 
==Feeding==
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Special goldfish food has a lower protein and higher carbohydrate content. It is sold in two consistencies - flakes that float at the top of the [[aquarium]], and pellets that sink slowly to the bottom.
 
Special goldfish food has a lower protein and higher carbohydrate content. It is sold in two consistencies - flakes that float at the top of the [[aquarium]], and pellets that sink slowly to the bottom.
   
Goldfish enthusiasts will supplement this diet with shelled [[pea]]s (with outer skins removed), [[blanched]] [[green leafy vegetable]]s, and [[bloodworm]]s. Young goldfish also benefit from the addition of [[brine shrimp]] to their diet. As with all animals, individual goldfish will display varied food preferences. In any case, it is better to feed them a variety of foods listed above.
 
 
{{see also|Fish food}}
 
   
 
==Behavior==
 
==Behavior==
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Because goldfish like to eat live plants{{Fact|date=September 2007}}, their presence in an aquarium can be quite a problem{{Fact|date=September 2007}}. Only a few of the aquarium plant species can survive in a tank with goldfish, for example ''[[Cryptocoryne]]'' and ''[[Anubias]]'' species, but they require special attention so that they are not uprooted. Fake plants are often more durable, but the plant branches can often irritate{{Fact|date=September 2007}} or harm a fish if it comes in contact with them.
 
Because goldfish like to eat live plants{{Fact|date=September 2007}}, their presence in an aquarium can be quite a problem{{Fact|date=September 2007}}. Only a few of the aquarium plant species can survive in a tank with goldfish, for example ''[[Cryptocoryne]]'' and ''[[Anubias]]'' species, but they require special attention so that they are not uprooted. Fake plants are often more durable, but the plant branches can often irritate{{Fact|date=September 2007}} or harm a fish if it comes in contact with them.
   
{{see also|List of freshwater aquarium plant species}}
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==Breeding==
 
==Breeding==
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Like some other popular aquarium fish, such as the [[guppy]], goldfish, and other carp are frequently added to [[stagnant (water)|stagnant]] bodies of water in order to reduce the [[mosquito]] populations in some parts of the world, especially to prevent the spread of [[West Nile Virus]], which relies on mosquitoes to migrate. However, the [[introduced species|introduction]] of goldfish has often had negative consequences for local [[ecosystem]]s.<ref>{{cite web | url=http://www.mosquitoes.org/fpconst.html | title=Information on Mosquito Prevention and Control in Fish Ponds | accessdate=2006-07-28}}</ref><ref>[http://www.d.umn.edu/~wint0190/comp%20page/Gold%20Paper/goldpaper2.2%20FD%20web.htm Gold fish as invasive species]</ref> As a result, goldfish are considered a pest in many countries, including the USA.{{Fact|date=November 2007}}
 
Like some other popular aquarium fish, such as the [[guppy]], goldfish, and other carp are frequently added to [[stagnant (water)|stagnant]] bodies of water in order to reduce the [[mosquito]] populations in some parts of the world, especially to prevent the spread of [[West Nile Virus]], which relies on mosquitoes to migrate. However, the [[introduced species|introduction]] of goldfish has often had negative consequences for local [[ecosystem]]s.<ref>{{cite web | url=http://www.mosquitoes.org/fpconst.html | title=Information on Mosquito Prevention and Control in Fish Ponds | accessdate=2006-07-28}}</ref><ref>[http://www.d.umn.edu/~wint0190/comp%20page/Gold%20Paper/goldpaper2.2%20FD%20web.htm Gold fish as invasive species]</ref> As a result, goldfish are considered a pest in many countries, including the USA.{{Fact|date=November 2007}}
   
==Controversy==
 
{{details more|goldfish swallowing|feeder fish}}
 
Although edible, goldfish are rarely eaten. A fad among [[United States|North American]] college students for many years was swallowing goldfish as a [[stunt]] and as an initiation process for [[Fraternities and sororities|fraternities]]. The first recorded instance was in 1939 at [[Harvard University]].<ref name="Thinkquest">{{cite web | url=http://library.thinkquest.org/3205/SwalG.html | title=Swallowing Goldfish | accessdate=2006-07-21}}</ref> The practice gradually fell out of popularity over the course of several decades and is now rare.<ref name="Thinkquest"/>
 
 
In the [[Belgian]] city of [[Geraardsbergen]] an annual festival is held where the medieval tradition of swallowing a small fish swimming in a cup of wine still survives. There have been a couple of court cases in the last decade but the tradition seems to survive nonetheless. The fish used is often a goldfish because of its size and price.{{Fact|date=December 2007}}
 
 
[[Image:Goldfish Scooped Up.jpg|thumb|220px|right|Goldfish being scooped up.]]
 
In many countries, the operators of [[carnival]]s and [[fair]]s commonly give goldfish away in plastic bags as [[prize]]s for winning games. In the [[United Kingdom]], the [[government]] proposed banning this practice as part of its Animal Welfare Bill,<ref name=DEFRA/><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> However, in Rome, Italy, the city passed a law in late 2005, which banned the use of goldfish or other animals as carnival prizes. [[Rome]] has also banned the keeping of goldfish in goldfish bowls, on the premise that it is cruel for a fish to live in such a small, confined space.<ref name=bowlban>{{cite web | url=http://www.timesonline.co.uk/article/0,,13509-1844070,00.html | title=Rome bans goldfish bowls, orders dog owners on walks - World - Times Online | accessdate=2006-07-21}}</ref>
 
 
In the UK, the Animal Welfare Act 2006 prohibits deliberate and “unnecessary suffering” to animals, but contrary to widespread belief, it does not explicitly outlaw the feeding of live feeder fish such as goldfish to other fish. However, it does prohibit introducing two animals for the purpose of “fighting, wrestling or baiting”.<ref name=DEFRA>{{cite web|url=http://www.defra.gov.uk/animalh/welfare/bill/index.htm|title=Defra, UK - Animal Health and Welfare - Animal Welfare - Animal Welfare Bill|author=[[DEFRA]]|accessdate=2006-11-30}}</ref> Nonetheless, the assumption is that a legal case could be made to class the use of feeder fish as a "fight" and though as-yet untried in the courts, the risk of such a prosecution has led many retailers and hobbyists simply to treat the use of feeder fish in the UK as illegal.{{Fact|date=February 2007}}
 
   
 
==See also==
 
==See also==
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*Golden [[tench]]
 
*Golden [[tench]]
 
*[[Koi]]
 
*[[Koi]]
* [[List of freshwater aquarium fish species]]
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==References==
 
==References==
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==Further reading==
 
==Further reading==
* “An Interpet Guide to Fancy Goldfish” by Dr. Chris Andrews, Interpet Publishing, 2002 - ISBN 1-902389-64-6
 
* “Fancy Goldfish: A Complete Guide to Care and Collecting” by Dr. Erik L. Johnson, D.V.M. and Richard E. Hess, Weatherhill, Shambala Publications, Inc., 2006 - ISBN 0-8348-0448-4
 
 
*[http://www.chipsbooks.com/goldfish.htm “Goldfish Varieties and Genetics: A Handbook for Breeders” by Joseph Smartt, Publisher: Blackwell Science (July 30, 2001), 216 pages] ISBN 0852382650 and ISBN 978-0852382653
 
*[http://www.chipsbooks.com/goldfish.htm “Goldfish Varieties and Genetics: A Handbook for Breeders” by Joseph Smartt, Publisher: Blackwell Science (July 30, 2001), 216 pages] ISBN 0852382650 and ISBN 978-0852382653
   
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* {{ITIS|ID=163350|taxon=Carassius auratus|year=2004|date=5 October}}
 
* {{ITIS|ID=163350|taxon=Carassius auratus|year=2004|date=5 October}}
 
* {{FishBase_species_alt|ID=271|taxon=Carassius auratus auratus|year=2004|month=September}}
 
* {{FishBase_species_alt|ID=271|taxon=Carassius auratus auratus|year=2004|month=September}}
* [http://news.bbc.co.uk/2/hi/uk_news/england/devon/4341254.stm Article on the oldest Goldfish, Goldie]
 
* {{dmoz|Recreation/Pets/Fish_and_Aquaria/Freshwater/Species/Goldfish/}}
 
* [http://americangoldfish.org American Goldfish Association]
 
* [http://www.petsparade.co.uk/articles/?a=7 Why do I need an Aquarium filter?]
 
* [http://www.kepu.net.cn/english/goldfish/index.html Chinese goldfish varieties]
 
* [http://www.bristol-aquarists.org.uk/goldfish/goldfish.htm Bristol Aquarists Society guide to goldfish varieties]
 
   
{{Goldfish breeds}}
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{{enWP|Goldfish}}
 
{{enWP|Goldfish}}
   
Related Link:
 
   
[http://wellspringwatersystems.com/solutions/waterbox-100 '''Ultrafiltration Systems''']
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[[Category:Carp| ]]
 
[[Category:Carp| ]]
 
[[Category:Fishes]]
 
[[Category:Fishes]]
 
[[Category:Pets]]
 
[[Category:Pets]]
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Latest revision as of 06:15, April 8, 2010

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?Goldfish
Conservation status: Least concern
A Hama Nishiki goldfish (a relation of the Pearlscale fancy goldfish variety)
A Hama Nishiki goldfish (a relation of the Pearlscale fancy goldfish variety)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Genus: Carassius
Species: C. auratus
Subspecies: C. a. auratus/C. a. gibelio
Trinomial name
Carassius auratus auratus
(Linnaeus, 1758)

The goldfish, Carassius auratus, was one of the earliest fish to be domesticated, and is still one of the most commonly kept aquarium fish and water garden fish. A relatively small member of the carp family, the goldfish is a domesticated version of a dark-gray/brown carp native to East Asia. It was first domesticated in China[1] and introduced to Europe in the late 17th century.

Goldfish may grow to a maximum length of 23 inches (59 cm) and a maximum weight of 9.9 pounds (4.5 kg), although this is rare; few goldfish reach even half this size. The oldest recorded goldfish lived to 49 years,[2] but most household goldfish generally live only six to eight years, due to being kept in bowls.[3] A group of goldfish is known as a troubling.[4]

DescriptionEdit

The longest goldfish was measured at 47.4 cm (18.7 in) from snout to tail-fin end on March 24, 2003 in in Hapert, The Netherlands. It was owned by Joris Gijsbers.[5]

VarietiesEdit

Selective breeding over centuries has produced several color variations, some of them far removed from the "golden" color of the originally domesticated fish. Goldfish may also lose their "golden" color, or rather any goldfish color, by being kept in a dark room, this causes the scales to turn white. There are also different body shapes, fin and eye configurations. Some extreme versions of the goldfish need to be kept in an aquarium — they are much less hardy than varieties closer to the "wild" original. However, some variations are hardier, such as the Shubunkin.

FeedingEdit

File:FishesFood.jpg

Like most fish, goldfish are opportunistic feeders. When an excess of food is offered, they will produce more waste and feces, partly due to incomplete digestion of protein. Overfed fish can sometimes be recognized by feces trailing from their cloaca. Goldfish need only be fed as much food as they can consume in one to two minutes, and no more than twice a day. Extreme overfeeding can be fatal, typically by bursting of the intestines. This happens most often with selectively bred goldfish, which have a convoluted intestinal tract as opposed to a straight one in common goldfish. Novice fishkeepers who have newly purchased ryukin, fantail, oranda, lionhead or other fancy goldfish will need to watch their fish carefully for a few days, as it is important to know how much the goldfish will eat in a couple minutes of time. They also die without eating in a week.

Special goldfish food has a lower protein and higher carbohydrate content. It is sold in two consistencies - flakes that float at the top of the aquarium, and pellets that sink slowly to the bottom.


BehaviorEdit

Behavior can vary widely both because goldfish are housed in a variety of environments, and because their behavior can be conditioned by their owners. A common belief that goldfish have a three second memory has been proven completely false.[6] Research by the School of Psychology at the University of Plymouth in 2003 demonstrated that goldfish have a memory-span of at least three months and can distinguish between different shapes, colours and sounds. They 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. [7]

Scientific studies done on the matter have shown that goldfish have strong associative learning abilities, as well as social learning skills. In addition, their strong visual acuity allows them to distinguish between different humans. It is quite possible that owners will notice the 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 should learn to associate their owners and other humans with food, often “begging” for food whenever their owners approach. Auditory responses from a blind goldfish proved that he recognized one particular family member and a friend by voice, or vibration of sound. This behavior was very remarkable because it showed that he recognized the vocal vibration or sound of two people specifically out of seven in the house.

Goldfish also display a range of social behaviors. When new fish are introduced to the tank, aggressive social behaviors may sometimes be seen, such as chasing the new fish, or fin nipping. These usually stop within a few days.[8] Fish that have been living together are often seen displaying schooling behavior, as well as displaying the same types of feeding behaviors. Goldfish may display similar behaviors when responding to their reflections in a mirror.

Goldfish that have constant visual contact with humans also seem to stop associating them as a threat. After being kept in a tank for several weeks, it becomes possible to feed a goldfish by hand without it reacting in a frightened manner. Some goldfish have been trained to swim through mazes, push a ball through a hoop, or even swim in a synchronized routine by their owners.[9]

Goldfish have behaviors, both as groups and as individuals that stem from native carp behavior. They are a generalist species with varied feeding, breeding, and predators avoidance behaviors that contribute to their success in the environment. As fish they can be described as “friendly” towards each other, very rarely will a goldfish harm another goldfish, nor do the males harm the females during breeding. The only real threat that goldfish present to each other is in food competition. Commons, comets, and other faster varieties can easily eat all the food during a feeding before fancy varieties can reach it. This can be a problem that leads to stunted growth or possible starvation of fancier varieties when they are kept in a pond with their single-tailed brethren. As a result, when mixing breeds in an aquarium environment, care should be taken to combine only breeds with similar body type and swim characteristics.

Native environmentEdit

Goldfish natively live in ponds, and other still or slow moving bodies of water in depths up to 20 m (65 ft). Their native climate is subtropical to tropical and they live in freshwater with a pH of 6.0–8.0, a water hardness of 5.0–19.0 dGH, and a temperature range of 40 to 106 °F (4 to 41 °C) although they will not survive long at the higher temperatures. They are considered ill-suited even to live in a heated tropical fish tank, as they are used to the greater amount of oxygen in unheated tanks, and some believe that the heat burns them. However, goldfish have been observed living for centuries in outdoor ponds in which the temperature often spikes above 86 °F (30 °C). When found in nature, the goldfish are actually an olive green color.

In the wild, the diet consists of crustaceans, insects, and various plants.

While it is true that goldfish can survive in a fairly wide temperature range, the optimal range for indoor fish is 68 to 75 °F (20 to 23 °C). Pet goldfish, as with many other fish, will usually eat more food than it needs if given, which can lead to fatal intestinal blockage. They are omnivorous and do best with a wide variety of fresh vegetables and fruit to supplement a flake or pellet diet staple. [10]

Sudden changes in water temperature can be fatal to any fish, including the goldfish. When transferring a store-bought goldfish to a pond or a tank, the temperature in the storage container should be equalized by leaving it in the destination container for at least 20 minutes before releasing the goldfish. In addition, some temperature changes might simply be too great for even the hardy goldfish to adjust to. For example, buying a goldfish in a store, where the water might be 70 °F (approximately 21 °C), and hoping to release it into your garden pond at 40 °F (4 °C) will probably result in the death of the goldfish, even if you use the slow immersion method just described. A goldfish will need a lot more time, perhaps days or weeks, to adjust to such a different temperature.

Because goldfish like to eat live plants[How to reference and link to summary or text], their presence in an aquarium can be quite a problem[How to reference and link to summary or text]. Only a few of the aquarium plant species can survive in a tank with goldfish, for example Cryptocoryne and Anubias species, but they require special attention so that they are not uprooted. Fake plants are often more durable, but the plant branches can often irritate[How to reference and link to summary or text] or harm a fish if it comes in contact with them.


BreedingEdit

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Goldfish, like all cyprinids, lay eggs. They produce adhesive eggs that attach to aquatic vegetation. The eggs hatch within 48 to 72 hours, releasing fry large enough to be described as appearing like “an eyelash with two eyeballs”. Within a week or so, the fry begin to look more like a goldfish in shape, although it can take as much as a year before they develop a mature goldfish color; until then they are a metallic brown like their wild ancestors. In their first weeks of existence, the fry grow remarkably fast - an adaptation born of the high risk of getting devoured by the adult goldfish (or other fish and insects) in their environment.

Some scientists believe goldfish can only grow to sexual maturity if given enough water and the right nutrition. However if kept well, they may breed indoors, but not in a small fishbowl. Breeding usually happens after a significant change in temperature, often in spring. Eggs should then be separated into another tank, as the parents will likely eat any of their young that they happen upon. Dense plants such as Cabomba or Elodea or a spawning mop are used to catch the eggs.

Most goldfish can and will breed if left to themselves, particularly in pond settings. Males chase the females around, bumping and nudging them in order to prompt the females to release her eggs, which the males then fertilize. Due to the strange shapes of some extreme modern bred goldfish, certain types can no longer breed among themselves[How to reference and link to summary or text]. In these cases, a method of artificial breeding is used called hand stripping. This method keeps the breed going, but can be dangerous and harmful to the fish if not done correctly[How to reference and link to summary or text].

Like some other popular aquarium fish, such as the guppy, goldfish, and other carp are frequently added to stagnant bodies of water in order to reduce the mosquito populations in some parts of the world, especially to prevent the spread of West Nile Virus, which relies on mosquitoes to migrate. However, the introduction of goldfish has often had negative consequences for local ecosystems.[11][12] As a result, goldfish are considered a pest in many countries, including the USA.[How to reference and link to summary or text]


See alsoEdit

Several closely related species also have orange varieties:


ReferencesEdit

Further readingEdit

External linksEdit



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