Tuesday, June 26, 2007

Goldfish - Carassius Auratus

Goldfish are the domesticated Asiatic subspecies of Carassius auratus, the gibel carp (Above), 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.

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 dynasty (265-419) - gold colouration first recorded

Tang dynasty (618-907) - goldfish raised in captivity (in ponds) in Buddhist monasteries; common goldfish probably established

Nan Song dynasty (1127-1279) - goldfish raised in domestic ponds; white and red-and-white colouration developed

Ming dynasty (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 dynasty (1644-1911) - bronze and blue colouration

1728 - goldfish first bred in Europe (Holland)

1758 - goldfish classified as Cyprinus auratus by Linnaeus (reclassified as Carassius auratus in 1949)

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



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