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Mussel (/ ˈ m ʌ s ə l /) is the common name used for members of several families of bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.
The freshwater pearl mussel (Margaritifera margaritifera) is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae.. Although the name "freshwater pearl mussel" is often used for this species, other freshwater mussel species (e.g. Margaritifera auricularia) can also create pearls and some can also be used as a source of mother of pearl.
In contrast, one of the largest species of freshwater bivalves is the swan mussel from the family Unionidae; it can grow to a length of 20 cm (7.9 in), and usually lives in lakes or slow-flowing rivers. Freshwater pearl mussels are economically important as a source of pearls and mother of pearl. While some species are short-lived, others can ...
Margaritifera auricularia is a species of European freshwater mussel, an aquatic bivalve mollusk in the family Margaritiferidae, the freshwater pearl mussels.Formerly found throughout western and central Europe, the species is now critically endangered and is one of the rarest invertebrates worldwide, being confined to a few rivers in Spain and France.
Unionidae burrow into the substrate, with their posterior margins exposed. They pump water through the incurrent aperture, obtaining oxygen and food. They remove phytoplankton and zooplankton, as well as suspended bacteria, fungal spores, and dissolved organic matter.
Margaritiferidae is a family of medium-sized freshwater mussels, aquatic bivalve molluscs in the order Unionida. [1] [2] It is the most threatened of all unionid families.[3]The family is sometimes referred to as the freshwater pearl mussel family, [4] but "freshwater pearl mussel" more often applies to the species Margaritifera margaritifera.
A formal freshwater mussel fishing industry was established in the mid-1850s to take advantage of this natural resource. [17] The "pearl rush" to find freshwater pearls became so intense in some rivers that millions of freshwater mussels were killed in a few years. In some rivers and streams entire freshwater mussel beds were completely eliminated.
The two major classes of molluscs have representatives in freshwater: the gastropods (snails) and the bivalves (freshwater mussels and clams.) It appears that the other classes within the Phylum Mollusca -the cephalopods, scaphopods, polyplacophorans, etc. - never made the transition from a fully marine environment to a freshwater environment.