Prussian Carp

Description The Prussian carp belongs to the Cyprinidae family. It was introduced into the Prespa Lakes in the 1970’s and used to be regarded either as a sub-species of the goldfish (Carassius auratus auratus) or as its wild form, but is now considered a species in its own right. As a result, it is often described either under the scientific name Carassius auratus gibelio, reflecting its previously assumed connection with the goldfish, or under the name Carassius gibelio, emphasising its status as a separate species. In size and appearance the Prussian carp is deep-bodied and plump, its shape most reminiscent of those of the Crucian carp (Carassius carassius) and carp (Cyprinus carpio). Its sides and belly are pale yellow or silvery, rather than the golden yellow usually seen in Crucian carp. These two species also differ in the shape of their fins: the caudal (tail) fin of Crucian carp is straight, that of Prussian carp forked. The underside fins of a Crucian carp are reddish, while those of a Prussian carp are lighter in colour. The last simple anal and dorsal rays strongly serrated; 37-52 gill rakers; lateral line with 29-33 scales; freed edge of dorsal concave or straight anal fin with 5½ branched rays. In Crucian carp the membrane lining the body cavity (the peritoneum) is light coloured, while in Prussian carp it is almost black. A Prussian carp can grow to a length of 20-25 cm and a weight of some 250 g in five years. The species has a maximum length of 45 cm and, in favourable conditions, can reach a weight of 2-3 kg. Unlike the common carp Cyprinus carpio – there are no barbells.   Biology The Prussian carp is a warm water fish, and thrives best in shallow lagoons and estuaries (with a depth of just a few metres), shallow pools and lakes, and slow-flowing rivers with muddy beds. The species is associated with dense vegetation and feeds mainly on benthic organisms. It grows rapidly, reproduces efficiently, and competes with native fishes for food and space. In some parts of central Europe it has affected the range of other indigenous and commercially more valuable fish species. The species is able to reproduce by gynogenesis, a process which only gives rise to new females. The milt of male fish is needed to initiate the development of the eggs, but once the embryos form, the males are excluded. The offspring produced are thus copies of the female. It can also tolerate waters with relatively low oxygen levels.   Distribution Its geographical origin is Asia/South-East Asia (China, Taiwan, Korea, Japan, Kolyma River, Amur River basin). The natural range of the species is said to extend from western Siberia across into Europe, including the Ponto-Caspian region (Black and Caspian Seas) and large parts of south-eastern Europe. The wild form of Prussian carp was introduced in Germany from Asia, according to some reports as early as the 16th or 17th century.   Fishing significance Moderate for commercial, but interesting for recreational fishing. Possible ameliorative fishing.   Threats to human Fish pest.   Impact Interfering  within the spawning of native cyprinid species. Management Possible ameliorative fishing.