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BACKGROUND INFORMATION ABOUT GOLDFISH
This page contains short articles about the history of goldfish and colour
and finnage in goldfish, how to keep them (Golden Rules), common diseases, and
how to breed them; at the bottom of the page there is a glossary of terms. Follow
the links on the left to access these topics.
Wild type goldfish
are the domesticated Asiatic subspecies of Carassius auratus, the gibel
carp, a species that naturally shows a wide range of morphological variation
when raised in different environments. In its native China it inhabits rivers,
streams, ponds, lakes and ditches, living in running, still and even stagnant
water from 10°C to 32°C, growing to about 30 cm in length and 2.5 kg
in weight within 2-3 years and living for about 10 years. It is a delicious
food fish! It crosses readily with any ornamental goldfish, producing viable
offspring. To the right is a picture of the Asiatic gibel carp (picture courtesy
of Man Shek-Hay (1982) Hong Kong Goldfish, Urban Council, Hong Kong,
taken by the author at Plover Cove Reservoir, Hong Kong - the fish was safely
returned to the water).
Chronology of change (mutations)
All morphological changes from the wild type are the result of genetic mutations
which man has spotted and favoured by selective line breeding to perpetuate
them according to his fancy, although there is a strong tendency to revert to
wild type. Human husbandry of this species has unlocked its huge genetic potential,
but it has taken a tremendous amount of effort to select and stabilize desirable
gene combinations, as can be appreciated from the 1700-year chronology given
|Jin d. (265-419)
||gold colouration first recorded (d. = dynasty)
|Tang d. (618-907)
||goldfish raised in captivity (in ponds) in Buddhist monasteries;
common goldfish probably established
|Nan Song d. (1127-1279)
||goldfish raised in domestic ponds; white and red-and-white
|Ming d. (1368-1644)
||goldfish raised in bowls indoors as pets, enabling selection
for mutations that would not have survived (or been observed) in ponds;
double tail and anal fins, dorsal-less condition and short body evolved,
||matt scales and calico colouration; keeping of fancy goldfish,
once the preserve of the aristocracy, now widespread.
||goldfish first exported to Japan
||goldfish first exported to Europe (Portugal)
|Qing d. (1644-1911)
||bronze and blue colouration
||goldfish first bred in Europe (Holland)
||goldfish classified as Cyprinus auratus by Linnaeus (reclassified as Carassius auratus in 1949)
||goldfish first exported to America
||pompon and pearlscale; shubunkin colouration developed in
||comet and veiltail
||Bristol shubunkin standard promulgated
(In that ancient records could have been made then lost, or could considerably
post-date the events they describe, one should be circumspect about such chronologies).
Most of the changes are recessive compared with the wild type (hence the tendency
to revert to wild type) but are dominant amongst domesticated stock (such as
the mutation for matt scales). Where alleles (versions of a gene, one inherited
from each parent) are both dominant (co-dominant), an intermediate condition
between the two results; for example, nacreous scales (see Colour below) occur
when the genes for both reflective and matt scales are present.
The only character inherited in a simple Mendelian manner is the globe eye
condition; all the other characters are polygenic.
Goldfish in Chinese art
From silks to ceramics to jade carvings, goldfish have found their way into Chinese art since the Ming dynasty, when they began to be kept as pets. The usual aspect was the top view until glass tanks were introduced, when side views began to feature. Illustrated on the right is a modern Chinese jade carving of fancy goldfish types, of exceptional quality; click on the image for an enlargement and further, equally fine examples, plus a few words of comment.
Goldfish colour chart
The matter of colour in goldfish is complicated, and this new goldfish colour chart (January 2014) summarizes the available information into a single table, and includes information on breeding outcomes. This is a large table, so you may prefer to download it as a PDF document.
Several normally drab species have a natural tendency to produce red-golden
colouration, including the orfe and the tench, the golden forms of which are
familiar to fishkeepers; the goldfish (the golden form of the gibel carp) was
first recorded in the Jin
(265-419 A.D.). Some 800 years later, red
and white colouration was first recorded. After a further 300 years calico fish
were first recorded, but these were lacking in blue, which first appeared some
100-200 years later during the Qing dynasty (1644-1911 AD) together with bronze.
Finally, shubunkins first appeared in Japan about 100 years ago, and the Bristol
shubunkin standard was drawn up in 1934.
The colour of goldfish is environmentally influenced, light being the most
important factor: fish raised in a dim environment (such as deeper ponds, rivers,
etc) develop (and retain) pale colouration, whereas fish raised in a bright
environment develop brighter, saturated colours. Diet also affects colour, and a number of colour-enhancing goldfish foods are available, although the effectiveness of these varies.
Pigment types, colour combinations and reflective qualities
There are three types of pigment cells in goldfish (according to research from Aquarian in 2006):
||melanophores containing the dark pigment melanin
||erythrophores containing two classes of pigment, carotenids and pteridines; animals including fish cannot themselves synthesize carotenids and need to acquire them in their diet
||xanthophores containing carotenid pigments
Most pigments are located in chromatophore cells, but pigments may also be found 'free' on the body surface or deeper within the body tissues. The presence or absence of pigment cells in different combinations, together
with variations in the chemical composition of the pigments and the location
of the pigments, gives the following range of colours:
||in wild goldfish, melanophores and xanthophores are abundant, together with a well-developed guanine (silvery) layer in the skin (see next section below); this combination of pigments gives the brown upper body surface (adaptive for camouflage when viewed from above) and the silvery-grey flanks (adaptive for camouflage when seen from the sides and below)
||when melanophores are absent (as a result of genetic mutation), the fish is gold, orange or yellow, depending upon the position and number of erythrophores and xanthophores present
||goldfish with red colouration have abundant erythrophores
||white goldfish have no pigment cells
||melanophores mixed with xanthophores all over the body surface (as distinct from the wild-type pigment distribution) give different hues
of bronze and iron, including chocolate brown
||in nacreous/matt fish (see below), when there are very few
melanophores and these are located deep within the skin (in areas where there are no overlying xanthophores
or erythrophores), the apparent colour to the observer is blue
||black goldfish have abundant melanophores lying close to
the skin, giving a matt, velvety black if guanine is absent and a metallic black if guanine is present; metallic fish with less abundant melanophores are grey, although this is often marketed as 'blue'
In addition to pigment cells, there is a guanine layer in the skin just below
the scales. There are two classes of cells containing guanine:
||these contain small crystals of guanine
||these contain large crystals of guanine and produce the iridescence and reflectivity of the body surface
All goldfish scales are in fact transparent; the nature of the
guanine layer beneath the scales gives the following range of effects:
||silvery, reflective scales
|nacreous (dull mother-of-pearl) scales
Colour types in goldfish
All ornamental goldfish are born with one of three colour types: wild type, bronze or
pink (albino). Any pinks and bronzes are culled by selective breeders, and the
wild type colouration slowly changes (as melanophores are gradually lost) from
black/grey to the adult, ornamental colouration; however, some fish (such as moors and pandas) retain the melanophores into adulthood.
Ornamental colour groups
There are two ornamental colour groups in goldfish:
Metallic fish may be either all the same colour (self-coloured), the range
of colours being red, orange, yellow, 'blue', brown and black, or a mix of colours
(variegated), the colours being as before with the addition of silver and arranged
in a pleasing pattern similar on each side. Metallic fish have reflective scales
owing to the guanine layer present in the skin (see above); pigment cells are
on the surface of the skin and colours appear as burnished metal on the body
and should be spread throughout the fish including the fins.
Many metallic and variegated twintail fish have dull body colour and lack colour in
all but the roots of the fins; fully coloured fish are the more highly prized
and do better in shows.
The colouration of the metallic group is complicated by the fact that there are thought to be three gene types: metallic, bluebelly and mock metallic. They have a very similar appearance and the difference is in the breeding outcomes when bred with other colour types. This (during 2010 - 2013/14 and beyond) is being investigated by breeders.
Calico fish have a varying pattern of a few fully reflective scales (guanine present) and mostly
matt scales (guanine absent) and nacreous scales (guanine partly present). Where
matt scales are present, the following effects are seen: if there are no pigment
cells then the body appears pink; if pigment cells are present at depth within
the skin then melanophores appear to give a background blue colour (rather than
black) and other colours appear more subtle including violet, grey and brown;
if pigment cells are present on the surface then matt (rather than reflective)
colours are seen.
The colouration of the calico group is complicated by the fact that there are thought to be three gene types: calico, pseudomatt and coloured matt. They have a very similar appearance and the difference is in the breeding outcomes:
- When breeding calico fish, generally only 50% of fry are calico, 25% are pinks
and 25% are bronzes.
- When breeding pseudomatt fish, the result is mock metallic, calico and pseudo-matt fish.
- When breeding coloured matt fish, the result is 100% coloured matts.
This too (during 2010 - 2013/14 and beyond) is being investigated by breeders.
Midnights are initially calico coloured but as the fish age the colour turns black.
A balance of colours and reflective properties with an overall blue background
is regarded as the ideal calico combination, and has a special term: shubunkin (which means red brocade in Japanese, the name coming from the overall red-on-blue
The term seems to be used for singletail fish only, namely the London and Bristol
shubunkins and the Japanese shubunkin (the 'comet' shubunkin).
All individual fins in goldfish are made up of a double layer; these lie flush
against each other, giving a single fin two layers thick. The common goldfish,
comet, London and Bristol shubunkins are all single-finned like the wild type
If the fin layers split apart and grow separately from each other a double
fin results, each only one layer thick. The double caudal and anal fins of the
twintail varieties appeared as mutations in the Ming dynasty (some 600 years
ago), as did the absence of a dorsal fin; these three characters, together with
the shorter, deeper body shape, go to make up the eggfish, which is the oldest
of the short-bodied twintail types and is the basis of the lionhead, pompon,
celestial and bubble eye types.
There are long-bodied twintail types with the caudal fin completely divided,
for example the jikin (or peacock tail) and the wakin, and long-bodied tri-tail
types in which only the lower lobe is divided; these are less familiar to us
in the West than the short-bodied twintails.
Then there are the short-bodied, long-finned twintails, which were developed
from a short-finned twintail precursor (similar to the eggfish but with a dorsal
fin): veiltails, orandas, globe eyes and the broadtail moor.
Goldfish finnage and body plan
The paired (pectoral and pelvic) fins prevent the fish from pitching (rocking
up and down lengthwise) in the water; the median (caudal, dorsal and anal) fins
prevent it from yawing (wandering) and rolling (rocking from side to side);
forward movement is achieved by S-shaped undulations of the body and caudal
fin; steering and precise control of movement are achieved by varying the angle
of the pectoral fins.
The show standards used by BAS and illustrated in this website are the Nationwide Goldfish Standards of Great Britain published in 1995, jointly produced by four societies:
- Association of Midland Goldfish Keepers
- Bristol Aquarists' Society
- Goldfish Society of Great Britain
- Northern Goldfish and Pondkeepers Society
Four new standards are under development for the jikin, wakin, tosakin and ranchu; these are nearly complete and should be published in early 2010.
All of the approved varieties are judged on a common basis at shows. The maximum
points that may be awarded are as follows:
|condition and deportment
||The lower fin just before the
||Towards the front of the fish
||A fish excluding the fins
||Also described as chocolate
||Mixture of colours and reflective
||The apparent state of health
||Top of the head
||The way in which a fish carries
||Of the upper surface
||The single fin on top of the
||The fin complement of a fish
||Rasberry-like growth on the
||Below the eyes
||Without a shiny appearance
||With the appearance of being
||Marked with patches of various
||With a dull mother-of-pearl
||Over the gill plates
||The first, forward pair of
||Where the tail joins the body
||The second, ventral pair of
||Towards the rear of the fish
||Having only a single colour,
||The ideal fish
||Posterior edge of caudal fin
||Of the lower surface
© Bristol Aquarists' Society