By crossing individuals of different species and genera, it is possible to obtain organisms with a unique combination of traits characteristic of different species. The disadvantage of such hybrids is their sterility, which can sometimes be overcome by diploidization.

The crossing of forms that differ in origin or habitat. Hybridization of fish is carried out between species, genera, separate cultivated breeds. Hybridization is used to develop new breeds and to use the increased qualities of first-generation hybrids.

In order to breed highly productive fish adapted to the harsh conditions of the northern regions, the crossing of cultivated carp with wild carp from the Amur basin, characterized by high winter hardiness, has been carried out. Hybrids from this crossing are considerably superior to mirror and flaked carps in terms of viability (high winter hardiness, less susceptibility to diseases, etc.).