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

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...

, an

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Unionidae The Unionidae are a Family (biology), 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 a ...

, 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 Science Biology * Seashell, a hard outer layer of a marine ani ...

. 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, inv ...

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 harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...

and the

dredging Dredging is the excavation of material from a water environment. Possible reasons for dredging include improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing d ...

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 The duck mussel (''Anodonta anatina'') is a species of freshwater mussel in the family Unionidae, the river mussels. Description See Animalbase below (external link). Right and left valve of the same specimen: File:Anodonta anatina 01.jpg, Ri ...

'' or juvenile ''

Anodonta cygnea The swan mussel, ''Anodonta cygnea'', is a large species of freshwater mussel, an aquatic bivalve mollusc in the family Unionidae, the river mussels. Because of its morphological variability and its wide range of distribution, there are over 50 ...

'') 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, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

- 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 forc ...

. * Netherlands - present * Poland - endangered *

Slovakia Slovakia, officially the Slovak Republic, 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 west, and the Czech Republic to the northwest. Slovakia's m ...

- endangered * United Kingdom - se
Action plan for Pseudanodonta complanata
(British Isles - listed in

List of endangered species in the British Isles This is a list of United Kingdom Biodiversity Action Plan species. Some suffer because of loss of habitat, but many are in decline following the introduction of foreign species, which out-compete the native species or carry disease. See also th ...

) * 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