The swan mussel, ''Anodonta cygnea'', is a large

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

freshwater mussel Freshwater bivalves are one kind of freshwater mollusc, along with freshwater snails. They are bivalves that live in fresh water as opposed to salt water, which is the main habitat type for bivalves. The majority of species of bivalve molluscs ...

, an aquatic

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Unionidae The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is at its most diverse ...

, the river mussels. Because of its morphological variability and its wide range of distribution, there are over 500

synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

for this species.

Shell description

The shell is thin but large (approximately 10 to 20 cm) and rather flat, even at the umbo. The shell color is often pale greenish or brownish. It differs from ''

Anodonta anatina ''Anodonta'' is a genus of freshwater mussels in the family Unionidae, the river mussels. Species Species in this genus include: * ''Anodonta anatina'' Linné, 1758 – duck mussel * '' Anodonta beringiana'' Middendorff, 1851 – Yukon f ...

'' in being larger shell with straighter, more parallel dorsal and ventral margins; the growth lines of the inner, oldest part of the shell are finer and shallower, and reach the margin.

Distribution

Its native distribution is European-Siberian. The geographical distribution of this species is from the British Isles east to Siberia, and south into northern Africa. * Croatia *

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

– in Bohemia, in Moravia, vulnerable (VU); Czech code, Decree for implementation, No. 395/1992 Sb. (and No. 175/2006 Sb.) – highly threatened species *

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

– highly endangered (''stark gefährdet''); listed as a specially protected species in annex 1 in

Bundesartenschutzverordnung The Federal Species Protection Regulations, first adopted on 19 December 1986, is a set of federal regulations in Germany. These regulations protect wild plants and animals. They are the implementing rules promulgated by the government to give force ...

* The Netherlands * Poland –

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

* Slovakia * Sweden – quite rare * British Isles including

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

* Italy * Portugal * Denmark * Philippines

Habitat

This species is found in rivers and lakes. They have a strong pungent odor and are used by carp fisherman as bait.

References

External links

{{Taxonbar, from=Q777865 Anodonta Molluscs described in 1758 Taxa named by Carl Linnaeus