|Scientific Name:||Dreissena bugensis Andrusov, 1897|
|Taxonomic Notes:||A recent Dreissenid molecular phylogeny using COI and 16S sequences (Therriault et al. 2004) concluded that Dreissena bugensis and D. rostriformis actually represent distinct races of a single species (sequence divergence was 0.23 - 0.54%, comparable to intraspecific variability in other species). The authors recommended the ancestral name D. rostriformis be used, with two races, bugensis and distincta (Therriault et al. 2004, Orlova et al. 2005). However, there is still confusion over this.
This species is also regarded by some as a subspecies of the invasive Zebra Mussel D. polymorpha (M. Seddon pers. comm. 2009).
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Rintelen, T. & Van Damme, D.|
|Reviewer(s):||Böhm, M. & Collen, B.|
Dreissena bugensis has been assessed as Least Concern due to its widespread, abundant distribution and highly invasive tendencies. It is tolerant to a variety of habitats and demonstrates tolerance to habitat alteration. It is a major invasive species in European and North American freshwater systems and is threatening native fauna in these regions.
|Range Description:||This species is native to the middle and south Caspian Sea where it is found at depths of 20-80 m (Therriault et al. 2004). Whilst the closely related species D. rostriformis has never been reported outside this historical distribution, this species has spread from the Black Sea basin northeast along the Volga River into Russia, north along the Dnieper River into Ukraine, and west along the Danube canal and Rhine as far as the Netherlands (van der Velde and Platvoet 2007). This species has also spread to North America and Canada, where it was first reported (from Lake Ontario) in 1991 (Therriault et al. 2004), and has since spread throughout the Great Lakes region and southwest to the Mississippi River, Michigan, Missouri, New York, Nevada, Ohio, Pennsylvania, Colorado, Arizona and California (Benson et al. 2011, NatureServe 2010).|
Native:Azerbaijan; Iran, Islamic Republic of; Kazakhstan; Russian Federation; Turkmenistan; Ukraine
Introduced:Canada (Ontario); Netherlands; United States (Arizona, California, Colorado, Michigan, Missouri, Nevada, New York, Ohio, Pennsylvania)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This invasive species has steadily increased its abundance in Europe and North America in the last 10-20 years, colonizing freshwater rivers and lakes and decimating native mussel populations through competitive interference. This species has increased in abundance to the extent that it is now displacing the highly invasive Zebra Mussel (D. rostriformis) (Ricciardi and Whoriskey 2004).|
In a study by Schloesser and Masteller (1999) in Presque Isle Bay, Lake Erie, all native unionid (Unionidae) shells were found to be infested by dreissenids in 1991. In this year, they collected about 500 individual unionids belonging to fifteen species; in 1992, 246 individuals belonging to twelve species were collected; in 1993, 64 individuals of six species; in 1994, three individuals of three species; and in 1995, no unionids were found (Schloesser and Masteller 1999).
|Current Population Trend:||Increasing|
|Habitat and Ecology:||This species occurs in freshwater or oligohaline (less than 3%) rivers, lakes and canals; it was recorded at depths of 0-28 m in the Ukraine, but as deep as 130 m in the Great Lakes (Mills et al. 1996, Therriault et al. 2004).|
|Major Threat(s):||There are no threats affecting this species. This species itself threatens the biodiversity of the habitats it invades.|
|Conservation Actions:||This species has been given a NatureServe Global Heritage Status Rank of G5 (secure). There are no species-specific conservation measures in place, or needed, for this species, and actions should in fact be taken to limit its spread and population growth, before the negative impacts on many ecosystems become irreversible. Records demonstrate that this species can tolerate low levels of salinity, so that eventual colonization into estuarine and coastal areas of North America cannot be ignored (Mills et al. 1996). Further research is recommended to determine whether this species and D. rostriformis are separate species or two races of the same species.|
|Citation:||Rintelen, T. & Van Damme, D. 2011. Dreissena bugensis. The IUCN Red List of Threatened Species 2011: e.T188911A8661357.Downloaded on 24 October 2017.|
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