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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]
During the
Tang Dynasty, it was popular to dam 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 much smaller container.[1]
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 royal family were forbidden to keep goldfish of the gold (yellow) variety, yellow being the royal color. This probably is the reason why there are more orange goldfish than yellow goldfish, even though the latter are genetically easier to breed.[5]
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.[6]

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.[7]

edit] Varieties
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.

The main goldfish varieties are:
Black Moor
Bubble eye
Butterfly tail
Celestial eye
Panda Moor
Telescope eye

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 (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.

Rare varieties
Tosakin or curly fantail or peacock tail goldfish
Tamasaba or sabao
Meteor goldfish
Egg-fish goldfish
Curled-gill goldfish or reversed-gill goldfish

New varieties
Azuma nishiki - a
nacreous-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
Singachu or sakura singachu - a ranchu variant

edit] Revived varieties
Osaka ranchu - a ranchu relative
Izumo nankin - a ranchu-like variety

A comet goldfish. One of the most common varieties.

In ponds

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 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.

Goldfish pond

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 chemicals 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.[citation needed] 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.[citation needed]

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).[
citation needed]
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. [8]
The supposed reputation of goldfish dying quickly is often due to poor care amongst uninformed buyers looking for a cheap pet.[
citation needed] 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.[
citation needed]
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.[9]
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
chromatophores 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.[citation needed]
edit] Breeding

Reproducing goldfish
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[
citation needed]. 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[citation needed].
Thus the myth that pregnant goldfish are called twits is completely fallacious as goldfish can not get pregnant. In principle, there could be a word for a female fish with egg development such as 'twit'. But none is listed in any proper dictionary.
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.[13][14] As a result, goldfish are considered a pest in many countries, including the USA.[citation needed]

1 comment:

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