Danube bleak gravel bottoms. The females arrive later and deposit about twenty thousand eggs which stick to stones and gravel. These hatch after two or three days and the larvae stay among the gravel for another ten days before moving to backwaters and shallows where they feed on zooplankton, insect larvae and algae. The juvenile fish migrate down stream in the autumn or the spring of the following year. They may become mature in four to five years. Danube bleak The Danube bleak or Caspian shemaya ("Alburnus chalcoides") is a species of freshwater fish in the family Cyprinidae. It is found in
Common bleak young bleak, though the pointed upward turned mouth of the bleak is already distinctive at young stages. Young roach and ruffe have a wider body and a short anal fin. The bleak occurs in Europe and Western Asia: north of the Caucasus, Pyrenees and Alps, and eastward toward the Volga basin and North-Western Turkey. It is absent from the major southern peninsulas and most of British Isles except southeast England. It is however locally introduced in Spain, Portugal, and Italy. The bleak lives in great schools and feeds upon small molluscs, insects that fall in the water, insect larvae, worms,