The Danube bleak or Caspian shemaya (Alburnus chalcoides) is a species of freshwater fish in the family Cyprinidae.

It is found in Iran, Ukraine, Georgia, Armenia, Slovakia, Moldova, Greece, Czechia, Azerbaijan, Turkiye, Afghanistan, Austria, Bosnia and Herzegovina, Bulgaria, Croatia, Switzerland, Germany, Hungary, Italy, Romania, Russia, Serbia, Slovenia,[2] Turkmenistan, and Uzbekistan.

[6] It is a migratory fish, spawning in the headwaters of the rivers and then moving down to the lower parts, estuaries and brackish areas of sea.

[4][5] Male Danube bleaks assemble in May to July at spawning sites in fast flowing streams with gravel bottoms.

The females arrive later and deposit about twenty thousand eggs which stick to stones and gravel.