Silver carp (Carassius gibelio) is a freshwater fish of the carp family. It inhabits freshwater bodies of Europe (except Sweden and Finland) and Siberia. Acclimatized in India and North America. 2 subspecies: C. auratus auratus and C. auratus gibelio. It differs from Carassius carassius by its larger scales (28-34 scales in the lateral line), larger number of gill stamens (39-50), and silvery coloration of the body. Unlike Carassius carassius, it is more often found in large lakes and is common in the beds of large rivers. Maximum size is 40-45 cm in length and 1.6-2.0 kg in weight. It matures at the age of 2-4 years. Spawning is annual, portioned, extended, from early June to late July, at water temperature of 14-16°C. Absolute fecundity is 20-300 thousand eggs. Carassius gibelio is characterized by gynogenesis (populations without males). It feeds on algae, zooplankton organisms and benthic forms.

As a rule, the coloration of the scales is silvery-gray or greenish-gray, but occasionally specimens with golden and even pinkish-orange coloration are found. The ratio of height to body length can vary considerably depending on habitat conditions. The first ray of the dorsal and anal fins is a hard serrated spike, the other rays are soft. Individual specimens live up to 10-12 years.

The silver carp originally lived in the Amur River basin and adjacent water bodies. It was artificially settled in the 60s of the XX century in many water bodies of Siberia and Europe. Now it is imported to North America, India and other regions. At the same time, in European and Siberian reservoirs silver crucian carp gradually displaced the common (golden) carp until the latter disappeared completely.

Spawning is batch spawning, which can occur from one to three times a year, depending on water temperature. As a rule, there are 4-6 times fewer males than females, and in some reservoirs there are no males at all. In such reservoirs, silver carp females spawn with males of related fish species (roach, golden carp, tench, bream, carp and others). Real fertilization does not occur, since the sperm does not fertilize, but only stimulates the development of eggs. In the offspring in this case, only females appear. This method of reproduction is called gynogenesis.

Silver crucian carp is an object of fish breeding, like carp, and also an object of fishery, sport and amateur fishing. Hybrids of silver carp and carp have been created. On the basis of subspecies of silver carp in China in the XI century were bred aquarium goldfish and other ornamental breeds.