Freshwater bivalve
Encyclopedia
Freshwater bivalves are one kind of freshwater mollusc
s. They are bivalves which live in freshwater, as opposed to saltwater. Although the majority of species
of bivalve molluscs live in the sea, a number of different families of bivalves live in freshwater (and in some cases also in brackish water). These families belong to two different evolutionary lineages (freshwater mussels and freshwater clams), and the two groups are not closely related.
The two groups of bivalves live in many types of freshwater habitat, ranging from small ditches and ponds, to lakes, canals, and rivers.
Species in the two groups vary greatly in size. Some of the pea clams (Pisidium
species) have an adult size of only 3 mm. On the other hand, one of the largest species of freshwater bivalves is the swan mussel
, in the family Unionidae; it can grow to a length of 20 cm, and usually lives in lakes or slow rivers.
Freshwater pearl mussel
s are economically important as a source of freshwaterpearl
s and mother of pearl.
The Unionoida, of worldwide distribution, are the pearly freshwater mussels. All reproduce by means of a larval stage that is parasitic on fish. Many species are utilized as sources of mother-of-pearl.
Veneroida
The Veneroida is a large group of bivalve "clams", most of which are marine. However, several families occur in fresh and brackish waters.
Freshwater mollusc
Freshwater molluscs are those members of the Phylum Mollusca which live in freshwater habitats, both lotic such as rivers, streams, canals, springs, and underground cave streams and lentic such as lakes, ponds , and ditches.This article is about freshwater Mollusca in general; for information on...
s. They are bivalves which live in freshwater, as opposed to saltwater. Although the majority of species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of bivalve molluscs live in the sea, a number of different families of bivalves live in freshwater (and in some cases also in brackish water). These families belong to two different evolutionary lineages (freshwater mussels and freshwater clams), and the two groups are not closely related.
The two groups of bivalves live in many types of freshwater habitat, ranging from small ditches and ponds, to lakes, canals, and rivers.
Species in the two groups vary greatly in size. Some of the pea clams (Pisidium
Pisidium
Pisidium is a genus of very small or minute freshwater clams known as pill clams or pea clams, aquatic bivalve molluscs in the family Sphaeriidae.-Subgenera and species:Subgenera and species within the genus Pisidium include:...
species) have an adult size of only 3 mm. On the other hand, one of the largest species of freshwater bivalves is the swan mussel
Swan mussel
The swan mussel, Anodonta cygnea, is a large species of freshwater mussel, an aquatic bivalve mollusc in the family Unionidae, the river mussels....
, in the family Unionidae; it can grow to a length of 20 cm, and usually lives in lakes or slow rivers.
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 are economically important as a source of freshwaterpearl
Pearl
A pearl is a hard object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other...
s and mother of pearl.
Families of freshwater bivalves
UnionoidaUnionoida
Unionoida is an order of freshwater mussels, aquatic bivalve mollusks. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels...
The Unionoida, of worldwide distribution, are the pearly freshwater mussels. All reproduce by means of a larval stage that is parasitic on fish. Many species are utilized as sources of mother-of-pearl.
- 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:...
- 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...
- 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...
- 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...
- 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...
- 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...
- Iridinidae
Veneroida
Veneroida
The Veneroida or veneroids are an order of bivalve molluscs. They include some familiar forms such as saltwater clams and cockles, and a number of freshwater bivalves including zebra mussels....
The Veneroida is a large group of bivalve "clams", most of which are marine. However, several families occur in fresh and brackish waters.
- CorbiculidaeCorbiculidaeThe Corbiculidae, common name "basket clams", are a family of aquatic bivalve molluscs in the order Veneroida.Clams in this family release many juveniles into the surrounding waters that have hatched inside the clams . Fertilization is internal...
- SphaeriidaeSphaeriidaeThe Sphaeriidae are a family of small to minute freshwater bivalve molluscs, in the order Veneroida. In the USA they are commonly known as the pea clams and the fingernail clams.-Genera:Genera in the family Sphaeriidae include:* Musculium...
- DreissenidaeDreissenidaeThe Dreissenidae are a family of small freshwater mussels, aquatic bivalve mollusks. They attach themselves to stones or to any other hard surface using a byssus.-Genera:Genera within the family Dreissenidae include:* Congeria...
External links
- Bacon at http://clade.acnatsci.org/mussel/proj/grano_salis/etheriidae.html
- Info on Unionoida genera (with images) at http://www.inhs.uiuc.edu/~ksc/MusselGenera.html
- Info on Rhode Island freshwater clams and mussels http://seagrant.gso.uri.edu/factsheets/clams_fs.html