Danube bleak by the building of dams across many of the rivers. Landlocked populations survive in small rivers and reservoirs, breeding in the small streams above the dams. The main Caspian Sea population has found ways of spawning below the dams. Overfishing and pollution in the Caspian Sea could impact on the Danube bleak but in 2008 the IUCN Red List of Threatened Species listed it as being of "Least concern". The Danube bleak feeds on small crustaceans, worms, molluscs, insect larvae, insects and small fish. Male Danube bleaks assemble in May to July at spawning sites in fast flowing streams with
The Crab and the Fox their familiar pursuits and take up a business they know nothing about”. The fable appeared in the Medici manuscript in the 15th century and later among those recorded by Roger L'Estrange (1692). In Victorian times the story appeared in George Fyler Townsend’s new translation with the moral “Contentment with our lot is an element of happiness”. Crabs are not a natural food for foxes but anciently they were confused with crayfish and there is a freshwater species of crayfish that is eaten by foxes in the Balkan Danube region. There is in addition a South American Crab-eating Fox about which