A very large proportion of common goldfish breed true to type, which makes this fish good for beginners, but it is a difficult fish for showing because it is such a relatively simple fish (which makes it difficult to develop a strain that stands out above the ordinary); intensity of colour is the key to doing well at shows. This fish is more popular in other British goldfish societies than BAS. Young fish are very dark, if not black, and gradually develop the ornamental red (or orange, etc) colour over 1-2 years.
The common goldfish is metallic, either self-coloured or variegated. The calico version of this fish is called the London shubunkin and has the same body and fins as the common goldfish.
The common goldfish is known as the gold carp in the Far East and as the hibuna in Japan.
The common goldfish and London shubunkin standard is as follows:
The fish should be bright and alert. The body should be strong and sturdy with a smooth outline. The caudal fin should be short and slightly forked.
Ideal profiles are illustrated below:
These are the finest red common goldfish in UK and regularly win at all the major shows (here seen at BAS 2000).
Winners of the breeders' pairs at BAS 2003.
A very fine lemon yellow common goldfish, shown at BAS 2000. The website author had such a fish which lived in good health for 33 years (although after 20 years the colour gradually faded to silver).
Two more fine fish, shown at BAS 1999 on the left and BAS 2007 on the right.
Common goldfish with tancho colouration (silver-white body with a red patch on the head, a colour scheme found in koi). Shown at BAS 2007.
These fish are black common goldfish, developed in China, and seen in Hong Kong in 2014; such fish are available from aquatic outlets in UK. (We apologize for the poor quality of the photographs; the fish were fast-swimming in a low-down, poorly lit tank - the fish photographer's nightmare - and no better pictures have been obtained since).
Only one BAS member regularly breeds the common goldfish: his strain is a very deep red with colour extending throughout the fins and with fairly deep bodies. Three of them are pictured above and are very similar in outline to the wild ancestor (see About Goldfish), which is hardly surprising.
The original fish were bought from a water garden centre 30 years ago: a thin but very red male and a deep-bodied yellow female. In the early years there were two successful outcrossings using fish from other members, for colour and shape enhancements; since then the line has been isolated from outside influences and consistently wins the common goldfish class at all the major shows.
About 30 mature fish are kept for breeding, with an even balance between the sexes. Two spawnings are made per season totalling about 4,000-5,000 fry of which about 100 are kept, giving a return of about 45:1 (i.e. 1 in 45 fry is kept until adulthood), a ratio which compares very favourably with other types such as fantails and lionheads. These 100 are kept for two years as it takes that long for the quality of the body colour to become apparent - it is difficult to produce good colour in young fish; eventually the very best 20 of these are kept, giving a return of about 250:1 to achieve show quality fish. These ratios well demonstrate the ease of breeding good common goldfish compared with other types, but the difficulty of breeding the very best, show-winning fish.
No particular breeding scheme is used; rather, the best-looking fish are chosen. Once a high quality strain is achieved then it is relatively easy to maintain, although in this strain the depth of colour has slowly declined over the last 10 years (although you wouldn't think so when you see the fish!) and it may perhaps be time for another outcross to re-fix the colour.
The breeding season starts in May. The fish are conditioned on earthworms and if it is a cold Spring then the tanks are heated to 65°F. The sexes are separated for 2-3 weeks and put together the night before the chosen spawning day, although sometimes spawning takes 2-3 days. The fish are left to it, there are always enough fertilized eggs in the tanks for maintenance of the strain.
Thereon the adults are fed carp pellets whilst the fry are fed LiquiFry, Tetra Baby Food and then Bemax. Little culling is necessary as the common goldfish has a simple shape and defects are slight, it's just a matter of keeping the best and finding homes for the rest.
The fish house is only ever heated to prevent freezing over in the all-glass tanks; in the years of metal-framed tanks they were allowed to freeze over - common goldfish are very hardy (provided the water is not too shallow). No filtration is used as water changes are 75% in the Winter months rising to 100% in the Summer months; for beginners, however, filtration is recommended. The tanks are cleaned in the Spring for spawning. No pests or diseases have been seen for many years as the fish are not brought into contact with any other fish; this experience contrasts with that of veiltail breeders, whose fish seem to pick up gill flukes from tapwater sometimes.
The common goldfish is an easy, hardy fish (obviously, provided that you follow the basic rules of fishkeeping - thousands of goldfish purchased from shops or won at fairs die each year) and lives for 10-12 years, although they can live for over 30 years (and according to some are good for 60 years). However, it is easy to knock off scales through mishandling which is a setback at show time, but they regrow.
© Bristol Aquarists' Society