Unionoida
Encyclopedia
Unionoida is an order
of freshwater mussels, aquatic
bivalve mollusks. The order includes most of the larger freshwater mussels, including the freshwater pearl mussel
s. All have in common a larval stage that is temporarily parasitic on fish, nacreous
shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment.
Families, genera, and species are found on six continents, where they are restricted exclusively to freshwater. Many face conservation issues due to habitat degradation or over-exploitation for their shell. There are approximately 900 species worldwide.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of freshwater mussels, aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
bivalve mollusks. The order includes most of the larger freshwater mussels, including the freshwater pearl mussel
Freshwater pearl mussel
The freshwater pearl mussel, scientific name Margaritifera margaritifera, is an endangered species of freshwater mussel, an aquatic bivalve mollusc in the family Margaritiferidae....
s. All have in common a larval stage that is temporarily parasitic on fish, nacreous
Nacre
Nacre , also known as mother of pearl, is an organic-inorganic composite material produced by some mollusks as an inner shell layer; it is also what makes up pearls. It is very strong, resilient, and iridescent....
shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment.
Families, genera, and species are found on six continents, where they are restricted exclusively to freshwater. Many face conservation issues due to habitat degradation or over-exploitation for their shell. There are approximately 900 species worldwide.
Families in the Order Unionoida
- EtheriidaeEtheriidaeEtheriidae is a family of medium-sized freshwater mussels, aquatic bivalve mollusks in the order Unionoida.-Genera within the family Etheriidae:* Acostaea d'Orbigny, 1851** Acostaea rivolii * Etheria Lamarck, 1807...
Swainson, 1840 - MargaritiferidaeMargaritiferidaeMargaritiferidae is a family of medium-sized freshwater mussels, aquatic bivalve mollusks in the order Unionoida. They are known as freshwater pearl mussels, because they are capable of producing pearls.-Genera within the family Margaritiferidae:...
Haas, 1940 - MutelidaeMutelidaeMutelidae is a family of medium-sized freshwater mussels, aquatic bivalve mollusks in the order Unionoida.-Genera within the family Mutelidae:* Aspatharia Bourguignat, 1885* Chambardia** Chambardia bozasi** Chambardia hartmanni...
Swainson, 1840 - UnionidaeUnionidaeUnionidae is a family of freshwater mussels, the largest in the order Unionoida, the bivalve mollusks sometimes known as river mussels, naiads, or simply as unionids.The range of distribution for this family is world-wide...
Fleming, 1828 - HyriidaeHyriidaeHyriidae is a family of pearly freshwater mussels in the order Unionoida native to South America, Australia, New Zealand and New Guinea. Like all members of that order, they go through a larval stage that is parasitic on fish. The classification recognized by Banarescu uses three subfamilies...
Swainson, 1840 - MycetopodidaeMycetopodidaeThe Mycetopodidae are a family of freshwater pearly mussels restricted to South America. They are named for the mushroom-like shape of their foot. Like all members of the Unionoida they reproduce via a larval stage that temporarily parasitizes fish...
Gray, 1840