Bleak belongs to the family Cyprinidae. Very agile and fast fish. The people of the bleak is also called shekels, becklake, Badkar, Sebel, perched, Cinta, zilavka. Every region has its own local name.
Bleak has the body oblong, strongly compressed laterally, the scales are very thin, shiny, easily disappears. Head strongly pointed anteriorly, mouth terminal, directed slightly upwards.
Has eyes are relatively large in size. Dorsal fin shorter than the anal. Back bleak gray-green, sides and belly silvery. All fins have the usual gray, and the ventral, pectoral and anal fins may be yellowish. At length the bleak reaches 15 – 20 cm, but in ponds with a good food can reach 100 grams. and more.
Bleak is a schooling fish. Inhabits open areas of lakes and slow rivers, not like weedy areas. A lot bleak hobnob in the basins of Azov, Black sea and Baltic sea, Belarus, Ukraine throughout the European part of Russia. Night stop near the thickets with low flow. At dusk and day is in constant motion, being close to the coast, often found near piers, bridges, rafts, and dams. In the summer in calm weather floating on the surface, windy weather makes deeper down. When the time is approaching autumn, bleak flocks become more numerous.
Bleak eats a variety of food. For example, youth, which reaches 5 cm, eats crustaceans, bloodworms, water beetles and other insects. In the diet of individuals of size more dominated by crustaceans and bloodworms. In various places the aquatic food composition bleak is not the same. In the bays bleak eats not only the air insects, mosquito larvae and water beetles, but also eats aquatic vegetation and algae, while in open water it does not eat plant food. In the upper part of the reservoir it feeds largely on insects and bloodworms, in the middle of the crustaceans, and in the lower part – more bloodworms and to a lesser extent, crustaceans.
Spawning begins bleak when the water reaches 15 – 17 degrees. Lays up to three servings of eggs, the duration of the spawning lasts more than two months. Upon reaching the two-year-old of age and a body length of about 9 cm comes puberty bleak. Females who have reached puberty and length 11 — 15 cm, can be very fruitful and to defer an average of 1,000 eggs.
Fluctuations in the length of the body bleaks the same age can be explained by dosing the spawning bleak, different than her generation manifest themselves in different food and other conditions. In the warm waters of the dimensions of the pond are a little more bleak, as there will be more feeding period.