Danube bleak branched rays while the anal fin has fifteen to nineteen. This fish is morphologically quite variable which may be due to local adaptations to various habitats but is more likely to be due to several species being involved. The Danube bleak occurs in slow flowing stretches of rivers flowing into the Black Sea and the Caspian Sea and in the Aral Sea basin, in Alpine rivers among others. 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. These migratory patterns have been disrupted
Omura's whale Omura's whale Omura's whale or the dwarf fin whale ("Balaenoptera omurai") is a species of rorqual about which very little is known. Before its formal description, it was referred to as a small, "dwarf" or "pygmy" form of Bryde's whale by various sources. The common name and specific epithet commemorate Japanese cetologist . The scientific description of this whale was made in "Nature" in 2003 by three Japanese scientists. They determined the existence of the species by analysing the morphology and mitochondrial DNA of nine individuals – eight caught by Japanese research vessels in the late 1970s in the Indo-Pacific