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Goldfish

2007 Schools Wikipedia Selection. Related subjects: Insects, Reptiles and
Fish

                    iGoldfish

                             Conservation status

   Secure
            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
   (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.
   A relatively small member of the carp family (which also includes the
   koi carp and the crucian carp), the goldfish is a domesticated version
   of a dark-gray/olive/brown carp native to east Asia (first domesticated
   in China) that was introduced to Europe in the late 17th century. The
   mutation that gave rise to the goldfish is also known from other
   cyprinid species, such as common carp and tench.

   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; most
   individual goldfish grow to under half this size. In optimal
   conditions, goldfish may live more than 20 years (the world record is
   49 years); however, most household goldfish generally only live six to
   eight years due to them often being kept in bowls.

History

   During the Tang Dynasty, it was popular to raise carp in ponds. As the
   result of a 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 smaller container.
   A crucian carp carrying a mutation for yellow pigment. Some of the
   first goldfish may have looked like this.
   Enlarge
   A crucian carp carrying a mutation for yellow pigment. Some of the
   first goldfish may have looked like this.

   In 1162, the empress of the Song Dynasty ordered the building of a pond
   to collect the red and gold variety of those carp. By this time, people
   outside the royal family were forbidden to keep goldfish of the gold
   (yellow) variety, yellow being the royal colour. This probably is the
   reason why there are more orange goldfish than yellow goldfish, even
   though the latter are genetically easier to breed.

   As time passed, more mutations occurred, producing new colour
   variations, and fancier varieties of goldfish were developed. 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 1611, goldfish were introduced to Portugal and from there to other
   parts of Europe. Goldfish were first introduced to North America in
   1874 and quickly became popular in the United States.

Varieties of domesticated goldfish

   Selective breeding over centuries has produced several colour
   variations, some of them far removed from the "golden" colour of the
   originally domesticated fish. There are also different body shapes, fin
   and eye configurations. Some extreme versions of the goldfish do 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. Here is an incomplete list of goldfish
   varieties.
     * Black Moor
     * Bubble Eye
     * Calico
     * Calico fantail
     * Celestial Eye
     * Comet
     * Common

                       * Fantail
                       * Lionchu
                       * Lionhead
                       * Oranda
                       * Panda Moor
                       * Pearlscale
                       * Pompom

                                     * Ranchu
                                     * Ryukin
                                     * Shubunkin
                                     * Telescope eye
                                     * Veiltail

Chinese goldfish 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 (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.

Goldfish in ponds

   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.
   Goldfish pond
   Enlarge
   Goldfish pond

   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 snails 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.

In the aquarium

   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 chemicals into the water. This also happens because goldfish
   cannot digest an excess of proteins, unlike most tropical fish.
   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 or fountain, more goldfish may be kept in the
   container.
   Goldfish aquarium
   Enlarge
   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. 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).

   The popular image of a goldfish in a small 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.

   The supposed reputation of goldfish dying quickly is often due to poor
   care amongst uninformed buyers looking for a "cheap" pet. The true
   lifespan of a well-cared-for goldfish in captivity can extend beyond 10
   years.

   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, can 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 colour. Since they are
   carp, goldfish are also capable of breeding with certain other species
   of carp and creating hybrid species.

   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 diverged to be considered separate
   species.

Feeding

   Common flake fish food
   Enlarge
   Common flake fish food

   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 three to four 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 ruykin, 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 few minutes of
   time.

   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 peas (with
   outer skins removed), blanched green leafy vegetables, and bloodworms.
   Young goldfish also benefit from the addition of brine shrimp to their
   diet.

Behaviour

   Behavior can vary widely both because goldfish are housed in a variety
   of environments, and because their behaviour can be conditioned by
   their owners. A common misconception that goldfish only have a three
   second memory has been proven completely false.

   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.

   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. Fish that have been living together are often seen
   displaying schooling behaviour, 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 "pet" a goldfish on the head,
   feed it by hand, or even cup a hand around it 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.

   Goldfish have behaviors, both as groups and as individuals that stem
   from native carp behaviour. They are a generalist species with varied
   feeding, breeding, and predators avoidance behaviours 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 environment

   Goldfish natively live in ponds, and other slow or still 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 colour.

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

   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.

   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, their presence in an aquarium
   can be quite a problem. 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 or harm a fish if it comes in contact with them.

Breeding

   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 colour; 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.

   Goldfish can only grow to sexual maturity if given enough water and the
   right nutrition. However if kept well, they may breed indoors. 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. 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.

Mosquito control

   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.

Edibility and cruelty

   Although edible, goldfish are rarely eaten. A fad among North American
   college students for many years was swallowing goldfish as a stunt and
   as an initiation process for fraternities. The first recorded instance
   was in 1939 at Harvard University. The practice gradually fell out of
   popularity over the course of several decades and is no longer
   continued.
   Goldfish being scooped up.
   Enlarge
   Goldfish being scooped up.

   In many countries, the operators of carnivals and fairs commonly give
   goldfish away in plastic bags as prizes for winning games. In the
   United Kingdom, the government proposed banning this practice as part
   of its Animal Welfare Bill, though this has since been amended to only
   prevent goldfish being given as prizes to unaccompanied minors.
   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's cruel to the fish to live in such a small, confined
   space.

   Killing fish humanely for human consumption or benign purposes (such as
   putting down an ill fish) is still legal in most countries (provided
   that the fish is not a protected fish caught in the wild, a fish in
   protected reserves or in water where the person concerned has no right
   to collect the fish). In the United Kingdom, it is illegal to sell live
   fish (including goldfish) as "feeder fish" for consumption by other
   animals.
   A distorted view of a goldfish in a goldfish bowl.
   Enlarge
   A distorted view of a goldfish in a goldfish bowl.

Care

     * Wikibook on goldfish care

Varieties

     * Goldfish Pages - Hobbyists web site that provides information on
       goldfish standards, goldfish varieties and goldfish care.
     * Goldfish varieties: Page 1 Page 2
     * Bristol Aquarists' Society - Photographs and descriptions of the
       different goldfish varieties
     * Goldfish Genetics - A resource on the genetics of the goldfish with
       a focus on the originator, crucian carp, and how their basic
       genetic package gave rise to the varieties of modern goldfish.

   Retrieved from " http://en.wikipedia.org/wiki/Goldfish"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
