Goldfish standards are used to measure how closely a fish resembles the accepted standard for its type. The closer it is to the standard, the higher the quality.
if Goldfish are left to spawn naturally, over a period of time they will eventually revert back to the wild form of the Prussian Carp.
This is proven in any spawning as there will be a large number of fry that don’t follow the traits of the parents. For example:
The more developed a goldfish variety is, the greater the number of fry in a brood that will have flaws.
Cross breeding varieties only produces worthless fish. It has taken many centuries to develop the goldfish varieties we have today but only one spawning to undo all that work.
Most goldfish keepers aren’t too worried about standards as long as their goldfish are orange/gold and have long flowing fins. However, if you are a goldfish enthusiast and plan to breed your goldfish, you should be aware of what the goldfish standards are for the variety you have.
Champion goldfish can be worth thousands of dollars. The reason for this is because of their rarity. The more developed the variety, the harder it is to produce a champion fish. From a brood of several thousand Lionhead fry, you will be lucky to get 10 juveniles that show enough early promise to possibly become a champion.
To get to this stage the juveniles will have had to pass all the requirements of the Lionhead standard. The 10 juveniles will be grown to adulthood when the final features of the standard develop, in the Lionhead’s case the wen or head growth.
Commercial breeders need to produce large numbers of goldfish for the pet shop market. The goldfish produced are called commercial quality fish. They conform to the major areas of an accepted standard for a particular variety but they can’t conform to all of them.
If we use the Black Moor as an example, by the time fish reach the pet shop they will have changed color to black, have two tails, be telescopic eyed and have a reasonably deep body.
The commercial breeder isn’t concerned about the other details that make up the Black Moor standard such as:
These details aren’t a consideration for the majority of customers that go to a pet shop to buy a few goldfish. It is a problem for the enthusiast because if pet shop fish are going to be used to start a goldfish dynasty, it will take longer to produce a champion fish (unless you are very lucky).
If you have an aquarium shop in your area that specializes in goldfish, you are more likely to get a goldfish that conforms more closely to a standard. An even better idea is to contact an aquatic club as some of the members will be experts in their field. You will be able to purchase fish from these experts that will conform far more closely to a standard than a commercial grade pet shop fish.
Commercial breeders or fish farms rarely cull fry. The fry are usually placed in large outdoor ponds once they are free swimming and left to their own devices until they are harvested. At this time they will receive a rough cull for obvious defects such as being uncolored or having a single tail if two is the standard.
This is why the amateur breeder is more likely to produce a champion fish, because the smaller scale operation allows more frequent culls of the brood. A single tailed Moor wouldn’t pass the first cull.
To confuse the issue of goldfish standards, there are two (major) versions that are followed, American standards issued by the American Goldfish Association (AGA) and English standards issued by the Nationwide Goldfish Societies UK.
Most standards in each are very similar, others are not.
As an example, the Black Moor in the English standard always has a veil tail, and anything less is considered an inferior specimen. In the American standard, the Moor can have either a forked tail or a veil tail.
If you intend to show your goldfish, you need to know what standards the judges will be using if you live outside the US or England.