Guldfisk historia

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  • cri
    • September 2002
    • 700

    Guldfisk historia

    Hej Whisse,
    Du nämnde att du gillar att läsa om GF. Här kommer lite historia och hur färgerna har avlats fram.
    Mvh,
    cri

    http://www.bristol-aquarists.org.uk/goldfish/info/info.htm

    THE HISTORY OF GOLDFISH
    Wild type goldfish

    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 below:

    Chun 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 colouration developed
    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, eggfish developed
    1590 red cap
    1592 globe eye
    1596 matt scales and calico colouration; keeping of fancy goldfish, once the preserve of the aristocracy, now widespread.
    1603 goldfish first exported to Japan
    1611 goldfish first exported to Europe (Portugal)
    Ching d. (1644-1911) bronze and blue colouration
    1728 goldfish first bred in Europe (Holland)
    1870 celestial
    1874 goldfish first exported to America
    1893 oranda/tigerhead
    1900 pompon and pearlscale; shubunkin colouration developed in Japan
    1908 bubble eye
    1911 curled operculum
    early 1900s comet and veiltail
    1934 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.


    COLOUR
    Colour mutations

    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 Chun dynasty (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 Ching dynasty (1644-1911 A.D.) together with bronze. Finally, shubunkins first appeared in Japan about 100 years ago, and the Bristol shubunkin standard was drawn up in 1934.

    Environmental influence

    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.

    Pigment types, colour combinations and reflective qualities

    There are either two or three types of pigment cells in goldfish:

    black melanophores
    yellow xanthophores
    red erythrophores (which may in fact be the same as xanthophores, according to some authorities)

    The presence or absence of these 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:

    gold in wild goldfish, only melanophores and xanthophores are present, together with a well-developed guanine (silvery) layer in the skin, giving the silvery-grey colour; when melanophores are absent (as a result of genetic mutation), the fish is gold, orange or yellow, depending upon the position and number of xanthophores present
    red goldfish with red colouration have abundant erythrophores present
    white white goldfish have no pigment cells
    bronze melanophores mixed with xanthophores give different hues of bronze and iron, including chocolate brown
    blue in nacreous/matt fish (see below), when there are very few melanophores and these are located deep within the skin (and xanthophores are absent), the apparent colour to the observer is blue; metallic 'blue' fish are actually grey
    black black goldfish have abundant melanophores lying close to the skin

    In addition to pigment cells, there is a guanine layer in the skin just below the scales - all goldfish scales are in fact transparent; the nature of the guanine layer gives the following range of effects:

    present silvery, reflective scales
    partly present nacreous (dull mother-of-pearl) scales
    absent matt scales

    Colour types in goldfish

    All goldfish are born with one of three colour types: wild type, bronze or pink (albino). The 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.

    Ornamental colour groups

    There are two ornamental colour groups in goldfish:

    metallic
    calico
    Metallic group

    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 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.

    Calico group

    Calico fish have a varying pattern of fully reflective scales (guanine present), 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.

    When breeding calico fish, generally only 50% of fry are calico, 25% are pinks and 25% are bronzes.

    Shubunkins

    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 colour pattern).

    The term seems to be used for singletail fish only, namely the London and Bristol shubunkins and the Japanese shubunkin (the 'comet' shubunkin).
    [Top]

    FINNAGE
    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 ancestor.

    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.

    <img src=icon_smile_cool.gif border=0 align=middle>

    Mvh, cri
  • whisse
    • July 2002
    • 312

    #2
    Wow, det var inte lite! Ska printa ut och läsa vid tillfälle =)

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