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
Common minke whale sharks have been found scavenging the blubber thrown overboard during Norwegian minke whaling operations off Svalbard. Great white sharks and blue sharks have also been observed feeding on a minke whale carcass off California. A new species of siboglinid annelid worm, "Osedax mucofloris", was discovered on the carcass of a 5.3 m (17.4 ft) female minke whale experimentally placed at a depth of 125 m (410 ft) in the North Sea. This genus of worm uses endosymbiotic bacteria to feed on the bones of whales that fall to the seafloor. Common minke whales are a host to a number of