|Scientific Name:||Dreissena polymorpha|
|Species Authority:||Pallas, 1771|
Mytilus polymorphus Pallas, 1771
|Taxonomic Notes:||A molecular phylogenetic analysis, using 16S and COI sequence data, maintained this as a separate species distinct from other closely related ones, e.g., D. rostriformis and D. stankovici (Therriault et al. 2004).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Van Damme, D.|
|Reviewer(s):||Böhm, M. & Collen, B.|
Dreissena polymorpha has been assessed as Least Concern. This species is widespread and abundant throughout both its native and introduced ranges. D. polymorpha is highly invasive and is therefore unlikely to be impacted by any major threats.
|Range Description:||This species is native to the drainage basins of the Black, Caspian and Aral Seas (Birnbaum 2006). It is a highly invasive mussel, and has spread throughout Europe, to southern Scandinavia and Britain, east into Eurasia and south to Turkey via shipping canals. Rather than a natural migration, this spread has been human-mediated and therefore this species classes as an alien in these regions (S. Nehring pers. comm cited in Birnbaum 2006). This species has also been discovered in Lake St. Clair in the Laurentian Great Lakes region (in 1988), and has since spread throughout North American freshwaters (Therriault et al. 2004).
Two subspecies are included: D. p. andrusovi (Andrusov 1897), which is restricted to the northern Caspian Sea; and D. p. aralensis (Andrusov 1897), occurring in waterbodies adjacent to the Aral Sea (Kantor et al. 2009).
Introduced:Afghanistan; Albania; Andorra; Armenia (Armenia); Austria; Azerbaijan; Belarus; Belgium; Bosnia and Herzegovina; Bulgaria; Canada (Ontario); China (Xinjiang); Croatia; Denmark; Estonia; Faroe Islands; France; Georgia; Germany; Greece; Hungary; India (Jammu-Kashmir); Italy; Kazakhstan; Kyrgyzstan; Latvia; Lithuania; Luxembourg; Moldova; Netherlands; Pakistan; Poland; Portugal; Romania; Russian Federation (Central European Russia, East European Russia, Kaliningrad, North European Russia, Northwest European Russia, South European Russia); Serbia (Serbia); Slovakia; Spain; Sweden; Switzerland; Tajikistan; Turkey (Turkey-in-Asia, Turkey-in-Europe); Turkmenistan; Ukraine; United Kingdom (Great Britain, Northern Ireland); United States (Georgia); Uzbekistan
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species can attain huge densities in parts of its range, sometimes up to 40,000 individuals per m2 (Birnbaum 2006).|
|Habitat and Ecology:||
This species occurs in a range of habitats, from freshwater to oligohaline waters in rivers, estuaries and coastal shallows of the Caspian Sea and other large brackish lakes (Therriault et al. 2004). In introduced regions, it has been found at depths of greater than 60 m (Therriault et al. 2004). It is most abundant on hard surfaces in calm waters upstream of dams (Birnbaum 2006).
Due to its bio-fouling properties (especially of ship hulls and industrial intake pipes, Birnbaum 2006) this species has had strong negative economic consequences in countries to where it has spread. It also has ecosystem-level impacts, including outcompeting native taxa, slowing down eutrophication, and bio-deposition, although these seem to manifest themselves towards the beginning of an invasion (Birnbaum 2006).
|Major Threat(s):||This species is widespread and highly invasive, so is unlikely to be impacted by any major threats.|
|Conservation Actions:||There are no species-specific conservation measures in place for this species.|
|Citation:||Van Damme, D. 2011. Dreissena polymorpha. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 23 September 2014.|
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