The depressed river mussel or compressed river mussel, ''Pseudanodonta complanata'', is a

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 ...

of freshwater mussel, an aquatic bivalve

mollusk 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 e ...

in the family

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 divers ...

, the river mussels. The species name comes from the flattened shape of its

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

. This species is found throughout northern Europe, but it is

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 in ...

throughout its range. While the survival of this species is thought to be threatened by

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

and the dredging of the slow-moving channels of water in which it lives, the species is also said to be "easily overlooked" (it can be confused with ''

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 ...

'' or juvenile '' Anodonta cygnea'') and thus it may be actually be more prevalent than current records show.

Distribution

Its native distribution is European. It has been recorded from: *

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, Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. nnotated list of mollusc species recorded outdoors in the Czech and Slovak Republics. ''

Malacologica Bohemoslovaca ''Malacologica Bohemoslovaca'' is a peer-reviewed open access scientific journal covering all aspects of malacology. It was published by the Slovak Academy of Sciences since 2005. It is published by the Department of Botany and Zoology, Faculty of ...

'', Suppl. 1: 1-37
PDF

(EN). It is endangered in Bohemia and critically endangered in Moravia. * Estonia - present. * Finland - not uncommon. * Germany ** critically endangered (''vom Aussterben bedroht'') ** Listed as strictly protected species and as 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 ...

. * Netherlands - present * Poland - endangered *

Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the s ...

- endangered * United Kingdom - se
Action plan for Pseudanodonta complanata
(British Isles - listed in List of endangered species in the British Isles) * Sweden - rare

References

Polish Red Data Book of Animals: Pseudanodonta complanata

Action plan for Pseudanodonta complanata

Nature Navigator: Detail of Depressed River Mussel
Unionidae Freshwater animals of Europe Bivalves of Europe Bivalves described in 1835 {{Unionidae-stub