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
Crab meat and the animal is then returned to the water. The practice is defended because some crabs can naturally autotomise (shed) limbs and then about a year later after a series of moults, regenerate these limbs. In Western Europe crab meat is derived primarily from the species "Cancer pagurus". "C. pagurus" is a large crab noted for the sweet, delicate flavour of its meat. It is also known as the "Brown Crab", the "Common Crab" or the "Edible Crab". The United Kingdom is the largest fishery for "C. pagurus" with large fisheries in Scotland and a smaller but substantial fishery in