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Contents [hide]

1 Description2 Life cycle and reproduction

3 Behavior4 Wild, in native environments5 Domesticated, in ponds6 In aquariums7 History8 Varieties

8.1 Chinese classification

8.2 Rare varieties8.3 New varieties8.4 Revived varieties

9 References10 Credits

Goldfish

Goldfish is the common name for afreshwater fish, Carassius auratus, ofthecarp or minnowfamily, Cyprinidae, that is native to EastAsia and has been domesticated anddeveloped into many ornamental breedsfor aquariums and water gardens.

One of the earliest fish to be domesticated—inChina over 1,000 years ago (BAS 2007)—thegoldfish remains one of the most popular

aquarium fish. Over the centuries, through human creativity acting on the foundationof an original carp species, many color variations have been produced, some fardifferent form the original "golden" color of the first domesticated fish. Diverse formshave also been developed. Beyond the aesthetic pleasure from such varieties,

Goldfish

A Hama Nishiki goldfish (a relation of the Pearlscalefancy goldfish variety)

Conservation status

Least ConcernScientific classification

Kingdom: AnimaliaPhylum: ChordataClass: ActinopterygiiOrder: CypriniformesFamily: CyprinidaeGenus: CarassiusSpecies: C. auratusSubspecies: C. a. auratus/C. a. gibelio

Trinomial nameCarassius auratus auratus

(Linnaeus, 1758)

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Reproducing goldfish

goldfish have also offered practical value in control of mosquitoes.

Description

A relatively small member of the Cyprinidae family, the goldfish is a domesticatedversion of a dark-gray/brown carp native to East Asia.

The Cyprinidae family is the largest family of freshwater fishes in the world, and maybe the largest family of vertebrates (with the possible exception of Gobiidae) (Nelson1994). Common names associated with various members of this family includeminnow,carp, chub, and shiner. Nelson (1994) recognizes 210 genera and over 2,000species in Cyprinidae, with about 1,270 species native in Eurasia, about 475 speciesin 23 genera in Africa, and about 270 species in 50 genera in North America.Particularly well-known species include the common carp and koi (Cyprinuscarpio), goldfish (Carassius auratus), and zebra danio or zebrafish (Brachydaniorerio), the latter used extensively in genetic research (Nelson 1994).

Members of the Cyprinidae are characterized by pharyngeal teeth in one or two rows,with no more than eight teeth per row; usually thin lips, an upper jaw usuallyprotrusible; and an upper jaw bordered only by premaxilla (Nelson 1994).

Goldfish, Carassius auratus, may grow to a maximum length of 23 inches (59 cm) anda maximum weight of 9.9 pounds (4.5 kg), although this is rare; few goldfish reacheven half this size. The longest goldfish was measured at 47.4 cm (18.7 in) fromsnout to tail-fin end on March 24, 2003 in Hapert, The Netherlands (Guinness 2003). Inoptimal conditions, goldfish may live more than 20 years, but most household goldfishgenerally live only six to eight years, due to being kept in bowls.

If left in the dark for a period of time, a goldfish will turn lighter in color. Goldfish havepigment production in response to light. Cells called chromatophores producepigments that reflect light, and gives coloration. The color of a goldfish is determinedby which pigments are in the cells, how many pigments molecules there are, andwhether 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 longperiod of time will lose its color.

A group of goldfish is known as a troubling (SDZ 2007).

Life cycle and reproduction

Goldfish, like all cyprinids, lay eggs. Theyproduce adhesive eggs that attach to aquaticvegetation. The eggs hatch within 48 to 72hours, releasing fry large enough to bedescribed as appearing like "an eyelash withtwo eyeballs."

Within a week or so, the fry begin to look morelike a goldfish in shape, although it can takeas much as a year before they develop amature goldfish color; until then they are ametallic brown like their wild ancestors. In theirfirst weeks of existence, the fry growremarkably fast—an adaptation born of thehigh risk of getting devoured by the adultgoldfish (or other fish and insects) in their environment.

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Some scientists believe goldfish can only grow to sexual maturity if given enoughwater and the right nutrition. If kept well, they may breed indoors. Breeding usuallyhappens after a significant change in temperature, often in spring. In aquariums, eggsshould then be separated into another tank, as the parents will likely eat any of theiryoung that they happen upon. Dense plants such as Cabomba or Elodea or aspawning 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 thefemales to release her eggs, which the males then fertilize. Due to the strange shapesof some extreme modern bred goldfish, certain types can no longer breed amongthemselves. In these cases, a method of artificial breeding is used called handstripping.This method keeps the breed going, but can be dangerous and harmful to thefish if not done correctly.

Like some other popular aquarium fish, such as the guppies, goldfish and other carpare frequently added to stagnant bodies of water in order to reducethe mosquitopopulations in some parts of the world, especially to prevent the spreadof West Nile Virus, which relies on mosquitoes to migrate (Alameda). However, theintroduction of goldfish has often had negative consequences forlocal ecosystems (Winter 2005).

Behavior

Behavior can vary widely both because goldfish are housed in a variety ofenvironments, and because their behavior can be conditioned by their owners. Acommon belief that goldfish have a three-second memory has been proven false(Henderson 2003). Research has demonstrated that goldfish have a memory-span ofat least three months and can distinguish between different shapes, colors andsounds (Henderson 2003). 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 toactivate it at the correct time (Henderson 2003; Lloyd and Mitchinson 2006).

Scientific studies done on the matter have shown that goldfish have strongassociative learning abilities, as well as social learning skills. In addition, theirstrong visual acuity allows them to distinguish between different humans. It is quitepossible that owners will notice the fish react favorably to them (swimming to the frontof the glass, swimming rapidly around the tank, and going to the surface mouthing forfood) while hiding when other people approach the tank. Over time, goldfish shouldlearn to associate their owners and other humans with food, often “begging” for foodwhenever their owners approach. Auditory responses from a blind goldfish proved thatit recognized one particular family member and a friend by voice, or vibration of sound.This behavior was very remarkable because it showed that the fish recognized thevocal 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 thetank, aggressive social behaviors may sometimes be seen, such as chasing the newfish, or fin nipping. These usually stop within a few days. Fish that have been livingtogether are often seen displaying schooling behavior, as well as displaying the sametypes of feeding behaviors. Goldfish may display similar behaviors when responding totheir reflections in a mirror.

Goldfish that have constant visual contact with humans also seem to stop associatingthem as a threat. After being kept in a tank for several weeks, it becomes possible tofeed a goldfish by hand without it reacting in a frightened manner. Some goldfish havebeen trained to perform various tricks.

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Goldfish pond

Goldfish have behaviors, both as groups and as individuals, that stem fromnative carpbehavior. They are a generalist species with varied feeding, breeding, andpredators avoidance behaviors that contribute to their success in the environment. Asfish they can be described as “friendly” towards each other, very rarely will a goldfishharm another goldfish, nor do the males harm the females during breeding. The onlyreal 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 beforefancy varieties can reach it. This can be a problem that leads to stunted growth orpossible 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, careshould be taken to combine only breeds with similar body type and swimcharacteristics.

Wild, in native environments

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

In the wild, the diet consists of crustaceans, insects, and various plants. They can bequite beneficial through consuming pest species, such as mosquitoes.

Fancy goldfish released into the wild are unlikely to survive for long as they arehandicapped by their bright fin colors; however, it is not beyond the bounds ofpossibility that such a fish, especially the more hardy varieties such as theShubunkin, could survive long enough to breed with its wild cousins. Common andcomet goldfish can survive, and even thrive, in any climate in which a pond for themcan be created. Introduction of wild goldfish can cause problems for native species.Within three breeding generations, the vast majority of the goldfish spawn will havereverted to their natural olive color. Since they are carp, goldfish are also capable ofbreeding with certain other species of carp and creating hybrid species.

Domesticated, in ponds

Goldfish are popular pond fish, since they aresmall, inexpensive, colorful, and very hardy. Ina pond, they may even survive if brief periodsofice form on the surface, as long as there isenough oxygen remaining in the water and thepond does not freeze solid.

Common goldfish, London and Bristolshubunkins, jikin, wakin, comet, andsometimes fantail can be kept in a pond all

year round in temperate and subtropical climates. Moor, veiltail, oranda, and lionheadare only safe in the summer.

Small to large ponds are fine for keeping goldfish, although the depth should be at

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Goldfish aquarium

least 80 centimeters (30 inches) to avoid freezing. During winter, goldfish will becomesluggish, stop eating, and often stay on the bottom. They will become active again inthe spring.

A filter is important to clear waste and keep the pond clean. Plants are essential asthey act as part of the filtration system, as well as a food source for the fish.

Compatible fish include rudd, tench, orfe, and koi, but the latter will require specializedcare. Ramshorn snails are helpful by eating any algae that grows in the pond. It is ofgreat 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 easilybecome overstocked. Koi may also interbreed to produce a sterile new fish.

In aquariums

Goldfish are usually classified as a coldwater fish and can live in unheated aquariums.Like most carp, goldfish produce a large amount of waste both in their feces andthrough their gills, releasing harmful chemicals into the water. Build-up of this wastetotoxic levels can occur in a relatively short period of time, which is often the cause ofa fish's sudden death. It may be the amount of water surface area, not the watervolume, that decides how many goldfish may live in a container, because thisdetermines how much oxygen diffuses and dissolves from the air into the water; onesquare foot of water surface area for every inch of goldfish length (370 cm²/cm). If thewater is being further aerated by way of water pump, filter, or fountain, more goldfishmay be kept in the container.

Goldfish may be coldwater fish, but this doesnot mean they can tolerate rapid changes intemperature. The sudden shift in temperature—for example at night in an office buildingwhere a goldfish might be kept in a smalloffice tank—could kill them. Temperaturesunder about 10 °C (50 °F) are dangerous togoldfish. Conversely, temperatures over 25 °C(77 °F) can be extremely damaging for goldfishand is the main reason why tropical tanks arenot desirable environments.

The popular image of a goldfish in a small fishbowl is an enduring one. Unfortunately,the risk of stunting, deoxygenation, and ammonia/nitrite poisoning caused by such asmall environment means that this is hardly a suitable home for fish, and somecountries have banned the sale of bowls of that type under animal rights legislation.

The supposed reputation of goldfish dying quickly is often due to poor care amonguninformed buyers looking for a cheap pet. The true lifespan of a well-cared-forgoldfish 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 agoldfish can be quite dangerous to its health, as it can cause the protective slime coatto be damaged or removed, which opens the fish’s skin up to infection from bacteria orparasites in the water.

While it is true that goldfish can survive in a fairly wide temperature range, the optimalrange 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 intestinalblockage. They are omnivorous and do best with a wide variety offresh vegetables andfruit to supplement a flake or pellet diet staple.

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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 thestorage container should be equalized by leaving it in the destination container for atleast 20 minutes before releasing the goldfish. In addition, some temperature changesmight simply be too great for even the hardy goldfish to adjust to. For example, buyinga goldfish in a store, where the water might be 70 °F (approximately 21 °C), andhoping to release it into your garden pond at 40 °F (4 °C) will probably result in thedeath of the goldfish, even if you use the slow immersion method just described. Agoldfish will need a lot more time, perhaps days or weeks, to adjust to such a differenttemperature.

History

Many sources claim that crucian carp (Carassius carassius) is the wild version of thegoldfish. Research by Dr. Yoshiichi Matsui, a professor of fish culture at KinkiUniversity in Japan, suggests that there are subtle differences that demonstrate thatwhile the crucian carp is the ancestor of the goldfish, they have sufficiently divergedto be considered separate species (Pearce 2006).

Others hold that the wild form of the goldfish (Carassius auratus auratus) is Carassiusauratus gibelio, or rather Carassius gibelio with auratus as the subspecies. Thedifferent species can be differentiated by the following characteristics:

C. auratus has a more pointed snout while the snout of a crucian carp is wellrounded.The wild form of the goldfish C. auratus gibelio or C. gibelio often has agray/greenish color, while crucian carps are always golden bronze.Juvenile crucian carp (and tench) have a black spot on the base of the tail, whichdisappears 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 have33 scales or more.

The goldfish was first domesticated in China (BAS 2007). During the Tang Dynasty, itwas popular to dam carp in ponds. It is believed that as the result of a dominantgeneticmutation, one of these carp displayed gold (actually yellowish orange) ratherthan silver coloration. People began to breed the gold variety instead of the silvervariety, and began to display them in small containers. The fish were not kept in thecontainers 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 tothe much smaller container (BAS 2007).

In 1162, the empress of the Song Dynasty ordered the construction of a pond tocollect the red and gold variety of those carp. By this time, people outside the royalfamily were forbidden to keep goldfish of the gold (yellow) variety, yellow being theroyal color. This probably is the reason why there are more orange goldfish than yellowgoldfish, even though the latter are genetically easier to breed (WetPetz 2004).

The occurrence of other colors was first recorded in 1276. The first occurrence offancy tailed goldfish was recorded in the Ming dynasty. Around the sixteenth centuryor beginning of the seventeenth century, goldfish were introduced to Japan (BAS2007), where the Ryukin and Tosakin varieties were developed.

In 1611, goldfish were introduced to Portugal and from there to other parts of Europe(BAS 2007). Goldfish were first introduced to North America around in the mid to late1800s and quickly became popular in the United States (Brunner 2003; BAS 2007).

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A crucian carp carrying a mutation foryellow pigment. Some of the first goldfishmay have looked like this.

A comet goldfish. One of the mostcommon varieties.

Varieties

Selective breeding over centuries has produced several color variations, some of themfar removed from the "golden" color of the originally domesticated fish. Goldfish mayalso lose their "golden" color, or rather any goldfish color, by being kept in a darkroom. There are also different body shapes, fin, and eye configurations. Someextreme versions of the goldfish need to be kept in an aquarium—they are much lesshardy than varieties closer to the "wild" original. However, some variations are hardier,such as the Shubunkin.

The main goldfish varieties are:

Black MoorBubble eyeButterfly tailCalicoCelestial eyeCometCommonFantailLionchuLionheadOrandaPanda MoorPearlscalePompomRanchuRyukinShubunkinTelescope eyeVeiltail

Chinese classificationIn Chinese goldfish keeping, goldfish areclassified into 4 main types, which are notcommonly used in the west.

Dragon eye - Goldfish with extended eyes, e.g. Black Moor, Bubble Eye, andtelescope eyeEgg - goldfish without a dorsal fin. e.g. lionhead (note that a bubble eye without adorsal fin belongs to this group)Wen - goldfish with dorsal fin and a fancy tail. e.g., veiltail ("wen" is also the nameof the characteristic headgrowth on such strains as oranda and lionhead)Ce (may also be called "grass") - goldfish without anything fancy. This is the typethat is usually used in Japanese carnivals, especially for "goldfish scoops."Jikin and wakin - goldfish with double tails, but with the body shapes of comets.

Rare varietiesTosakin or curly fantail or peacock tail goldfishTamasaba or sabaoMeteor goldfishEgg-fish goldfish

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A school of fancy goldfish.

Curled-gill goldfish or reversed-gillgoldfish

New varietiesAzuma nishiki - a nacreous-coloredorandaMuse - a cross between a tosakin andan azuma nishiki with black eyes andwhite translucent scalesAurora - a cross between a shubunkinand an azuma nishiki or between acalico jikin and a tosakinWillow - a long and willowy telescope-eyed comet or shubunkinDragon eye ranchu or squid ranchu - a telescope eyed ranchu varietySingachu or sakura singachu - a ranchu variant

Revived varietiesOsaka ranchu - a ranchu relativeIzumo nankin - a ranchu-like variety

References

Alameda County Mosquito Abatement District. Mosquito prevention considerationsfor fish ponds . Alameda County Mosquito Abatement District. RetrievedNovember 23, 2007.Andrews, C. 2002. An Interpet Guide to Fancy Goldfish. Interpet Publishing. ISBN1902389646 .Bristol Aquarists' Society (BAS). 2007. Background information aboutgoldfish .Bristol-aquarists.org. Retrieved November 23, 2007.Brunner, B. 2003. The Ocean at Home. New York: Princeton ArchitecturalPress.ISBN 1568985029 .Guinness World Records. 2003. Longest Guinness . WorldRecords.com.Retrieved July 14, 2007.Henderson, M. Goldfish pass memory test . The Times October 1, 2003.Retrieved August 21, 2006.Johnson, E. L., and R. E. Hess. 2006. Fancy Goldfish: A Complete Guide to Careand Collecting. New York: Weatherhill. ISBN 0834804484 .Lloyd, J., and J. Mitchinson. 2006. The Book of General Ignorance. New York:Harmony Books. ISBN 9780307394910 .Nelson, J. S. 1994. Fishes of the World. New York: John Wiley and Sons. ISBN0471547131 .Pearce, L. 2006. Common gold fish . Aquarticles. Retrieved June 20, 2006.San Diego Zoo (SDZ). 2007. San Diego Zoo's got questions? Animal groupnames . San Diego Zoo. Retrieved February 4, 2007.Smartt, J. 2001. Goldfish Varieties and Genetics: A Handbook for Breeders .Blackwell Science. ISBN 0852382650 .WetPetz. 2004. Carassius auratus . WetPetz. Retrieved July 21, 2006.Winter, T. J. 2005. Population size, growth, and control of exotic goldfish (Crassiusatratus) in a small impoundment: Implications for managing futureinvasions .University of Minnesota Duluth. Retrieved November 23, 2007.

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