|Synonyms||Carassius carassius auratus, Cyprinus auratus, Carassius auratus, Cyprinus mauritianus, Cyprinus thoracatus, Carassius chinensis, Cyprinus maillardi, Carassius auratus cantonensis|
|Distribution||Native to China, Hong Kong, Japan, Laos, Macau and Myanmar. Introduced to over 70 other countries, with several reporting adverse ecological impact.|
|Sexual Dimorphism||Mature females fuller bodied. Mature males are leaner and often longer-finned, showing breeding tubercles on gill plates & pectoral fins when in spawning condition.|
|Maximum Size||Usually up to 30cm (12"), although considerably larger specimens have been reported.|
|Water Parameters||Neutral to alkaline conditions preferred. pH: 7.0-8.0, dH: up to 25 degrees.|
|Temperature||Coldwater: 4-30 deg C (39-86 deg F)|
|Compatibility||Large fish community|
|Special Requirements||Avoid unfiltered bowls and small aquaria.|
Goldfish have been with us for a very long time, having been bred from food fishes in China over a thousand years ago. They're one of the world's most popular pets and that does have some drawbacks for them, as they don't always get the treatment they deserve. A sociable species, goldfish should be kept in groups but these can consist of a mixture of similar varieties - just make sure that female fish aren’t outnumbered by the more long-finned and lightly-built males, which chase them relentlessly during spawning.
Goldfish are a great choice for the garden pond. Hardy and long-lived, they’ll happily live amongst pond plants and don’t place too much of a burden on filtration, even as mature fish. When kept alongside varieties such as shubunkin and sarasa comets they’ll freely interbreed, with fry showing dark colouration that protects them from predators until they grow large enough to look after themselves.
In their long history as pets, it’s become common practice to keep goldfish indoors in containers that are much too small for them. As you can imagine, housing a 30cm pond fish in a bowl is not ideal and a suitable indoor aquarium should be at least 100 litres in capacity and well-filtered for young specimens. Far better alternatives are available for indoor keeping and tropical fish are far easier and a good deal less work. If your heart is set on goldfish as a pet, consider starting with small fish in a large aquarium which can then be upgraded to a spacious pond as they grow – obviously, this is only an option with pond-hardy varieties. Kept properly, these fish should live for decades, with the current record standing at 43 years.
Goldfish are hardy and adaptable fishes, but they prefer hard water whether indoors or out and soft, acidic conditions are to be avoided. To minimise the stresses of cold winter weather and hot summer days, a fishpond should be at least 60cm (2’) deep in places. During the coldest weather, this area should remain undisturbed by vigorous water circulation and will be used as a refuge from extreme cold.
Goldfish have been bred into a great variety of shapes and colours and these are generally split into two categories - Fancy forms with modified body shapes and single-tailed forms. Fancy goldfish are less hardy and are considered aquarium fish, whereas their more fish-shaped kin are generally regarded as pond fish. You'll find more detailed profiles on the databank that go into the care requirements of each. In terms of the classic orange pond goldfish, short-finned fish are referred to as common goldfish and long-finned are known as comets. It's best not to mix fancy and single-tailed forms.