The swan mussel has a thin fragile shell. It is found in fresh stationary waters. It has a foot so that it maneuver a bit. There is one known incident of a swan. Descriptions and articles about the Swan Mussel, scientifically known as Anodonta cygnea in the Encyclopedia of Life. Includes Overview; Brief Summary; Distr. Anodonta-cygnea_jpg. Anodonta cygnea. Provided by Welter Schultes, Francisco Locality: Germany: Schleswig-Holstein, Brammer Teich near Kiel.
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It differs from Anodonta anatina in aanodonta larger shell with straighter, more parallel dorsal and ventral margins; the growth lines of the inner, oldest part of the shell are finer and shallower, and reach the margin.
Occasionally found in Spain and Portugal in artificially disturbed habitats, where infected fishes from central Europe were released. Conservation of this species Current action Declaration as a Priority Species.
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The story may not end there, however, as the zebra mussel infestation is now waning and there is hope that the swan mussel can regain some of the territory lost to its competitor. It also has a deeper, less flattened shell with the interior more deeply anldonta with nacre.
Anodonta cygnea Linnaeus The parasitic larvae are called glochidia and are produced in spring and carried by the current until they contact a bottom-living fish. However, this increases where recent breeding and recruitment has been poor. Show history of this page. Glochidia are mature in autumn, are released in spring in England and in Italy amodonta, their size 0. Prefers muddy substrate bare of vegetation.
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WoRMS – World Register of Marine Species – Anodonta cygnea (Linnaeus, )
Home Introduction Selection Criteria:: From Wikipedia, the free encyclopedia. In brief A very large bivalve shell cygneq in silty or muddy backwaters of streams, rivers and lakes Threatened both in Ireland and Europe by diffuse pollution and the resultant periodic de-oxygenation of waters A more acute or short-term threat has been delivered by the invasive zebra mussel which competes for dissolved oxygen and food Red listed in Ireland as Vulnerable VU and as a Priority Species in Northern Ireland Species description A very large bivalve shell with a flattened profile and broad, oblong shape.
Its native distribution is European-Siberian. Because of its morphological variability and its wide range of distribution, there are over synonyms for this species. An annotated list of the land and freshwater Mollusca of Northern Ireland. Tolerates eutrophic conditions, but not in the last toxic stadium. Why is this species a priority in Northern Ireland?
This mussel is associated with relatively unpolluted slow streams and lakes with cugnea or silt bottoms, habitats which are in universal decline.
Malacologica Bohemoslovaca in Czech. Nomenclator Zoologicus Neave updated, cybnea.
Institute of Zoology, Slovak Academy of Sciences. Artificial lakes are usually reached when infected fishes are brought in, young mussels are rarely dispersed by water birds. Cygea of failure reports. Archived from the original on 19 October Threatened by continuous destruction of habitats, water current regulations, exaggerated pollution by fertilizers, also by natural drying out of waters.
Embryonal shell finely striated along the growth lines, the lines reach the margin. How to see this species Swan mussels can sometimes be seen from fishing stands at the margins of lakes with silty or mud bottoms.
This is smaller though still a large shell at mm long but usually with a more cygnez angular shape. In Switzerland in up to m altitude.
They have a strong pungent odor and are used by carp fisherman as bait. Retrieved 23 April The dorsal upper margin usually lies at an acute angle to the line of the ventral lower margin giving the shell a distinct wedge shape, instead of being almost parallel as in the swan mussel which produces a more oblong shape. They will then drop off after a period of weeks and find a suitable place on the bottom to begin an independent life.
Swan mussel Conservation status. Retrieved from ” https: Zebra mussels are unable to colonise streams where water flow is significant and it is thought that these streams may act as reservoirs of native mussels which will assist in re-colonisation.
Archived from the original on 14 February It was formerly common in such places but has been displaced by main drainage schemes in rivers, excess siltation, eutrophication and, recently, by the invasive zebra mussel Dreissena polymorpha.
Index Animalium Sherborn, species and genera until List of all anldonta. As settlement increases, the filtration activity of the zebra mussels competes with that of the swan mussel which either suffers respiratory failure or starvation.
It can reach mm 6 in in size and has a nearly straight dorsal upper or hinge margin with a drawn out posterior end and slightly rounded to nearly straight ventral lower margin.