Thick shelled river mussel

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Thick shelled river mussel
Conservation status
Near Threatened (IUCN 2.3)
Scientific classification
Kingdom: Animalia Phylum: Mollusca Class: Bivalvia Order: Unionoida Family: Unionidae Genus: Unio Species: U. crassus
Binomial name
Unio crassus Philipsson, 1788

The thick shelled river mussel, Unio crassus, is a mussel of the family Unionidae.

Contents 1 Ecology 2 Decline 3 Distribution and conservation status 4 References 5 External links

[edit] Ecology

As part of newly discovered reproductive behaviour, this mollusc crawls up to the edge of the water, exposing its excurrent aperture, and then lets loose a stream of water. The fountain of water often contains glochidia, and it is suggested that this spurting behavior may facilitate dispersal of mussel larvae.

[edit] Decline

The thick shelled river mussel declined in the beginning of the 20th century everywhere in Europe due to deteriorating water quality.

[edit] Distribution and conservation status

• IUCN Red List - Near threatened (NT)^[1]
• It is mentioned in annexes II and IV of Habitats Directive.

Its native distribution is European.

• The Czech Republic - endangered (EN).^{[2] [3]} It's Conservation status in 2004-2006 is bad (U2) in report for European commission in accordance with Habitats Directive.^[4]
• France ^[5]
• Germany - critically endangered (vom Aussterben bedroht) ^[6] In Germany this bivalve has disappeared from 90% of its former range.
• Netherlands - locally extinct. In the Netherlands it has not been seen alive after 1968 and is most likely extinct in that country.^{[7] [8]}
• Poland - endangered ^[9]
• Slovakia - „nearly threatened“ ^[10]
• Sweden - „very rare“ ^[11]

[edit] References

[edit] External links

• The Mussel Project Web Site