70 years ago, there were two main areas of guppy breeding - the first was to increase the size of fish (U.S. guppi selection), the second - to create new exciting colors and patterns (the Soviet Union's and european selection of guppy). The total between the two - the creation of new forms (standards), fins of fish.
Now the interests of a smooth transition in a commercial application area - not only beneficial to create a beautiful fish, but also a prolific (with the sex ratio toward increased number of males), with a good immuity and other physiological parameters.