The bleak is a fish of the cyprinid family. It occurs in Europe, from the White Sea in the north to Caucasus in the south. Bleak is common in rivers, lakes, ponds with flowing water and reservoirs. It can also be found in brackish water in bays and estuaries. It prefers open water and avoids overgrown areas, but it enjoys staying near bridges and posts. This fish is spry, it lives in schools. It feeds on plankton, insect larvae, aquatic plants, pollen, fish roe. The body of bleak is elongated and flat. On its belly, there is a keel without scaling. Its back is grayish blue with green shimmer, its sides and belly are light with metallic luster. The fins are gray. The anal fin is rather long. Its mouth is turned upwards. The bleak has big thin fragile scales. In the old times, the so-called “pearl essence” (used in making artificial pearls) was extracted from bleak scales. The bleak reaches a maximum length of 20 cm and a maximum weight from 60 to 70 g. Lake- and pond-dwelling bleak are usually bigger than river bleak.