''Mytilus'' is a

cosmopolitan Cosmopolitan may refer to: Internationalism * World citizen, one who eschews traditional geopolitical divisions derived from national citizenship * Cosmopolitanism, the idea that all of humanity belongs to a single moral community * Cosmopolitan ...

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of medium to large-sized edible, mainly saltwater

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...

s, marine

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Mytilidae The Mytilidae are a family (biology), family of small to large Marine life, marine and Brackish water, brackish-water bivalve molluscs in the order (biology), order Mytilida. One of the genera, ''Limnoperna fortunei, Limnoperna'', even inhabits f ...

Description

Mussels have a gray to blue-purple, fully grown shell about 5 - 10 centimeters long with an elongated oval shape. They follow the general blueprint of the mussels. They consist of a right and left half of the shell, which are held together with an elastic lock strap (ligament). The shell is made up of 3 layers: the top layer of organic material (periostracum), the middle thick layer of lime (ostracum) and the innermost, valuable, silver-white shiny mother-of-pearl layer (hypostracum). In the shell of the mussel there are two gills with gill leaves that are well supplied with blood. Between the gills is a muscular foot with the byssus gland. With the help of the protein contained in the mussel and iron filtered from the sea, this gland produces the byssus threads with which the mussel can hold on. Mussels have a sphincter, which is located in the soft tissue of the mussel, as well as other organs (heart, stomach, intestines, kidneys). With the help of the sphincter muscle, the mussel can close in danger or dryness.

Species

Species within the genus ''Mytilus'' include: * '' Mytilus californianus'' Conrad, 1837 - California mussel * '' Mytilus coruscus'' Gould, 1861 = ''M. unguiculatus'' Valenciennes, 1858 * the ''Mytilus edulis'' complex: ** ''

Mytilus edulis The blue mussel (''Mytilus edulis''), also known as the common mussel, is a medium-sized edible marine (ocean), marine bivalve mollusc in the family (biology), family Mytilidae, the only extant family in the order (biology), order Mytilida, known ...

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...

- blue mussel, edible blue mussel ** '' Mytilus galloprovincialis''

Lamarck Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biolo ...

, 1819 - Mediterranean mussel ** '' Mytilus planulatus''

, 1826 - Australian blue mussel ** '' Mytilus platensis''

d'Orbigny Alcide Charles Victor Marie Dessalines d'Orbigny (6 September 1802 – 30 June 1857) was a French naturalist who made major contributions in many areas, including zoology (including malacology), palaeontology, geology, archaeology and anthropol ...

, 1842 ** '' Mytilus chilensis'' Hupe, 1854 - Chilean blue mussel ** '' Mytilus trossulus'' Gould, 1850 - foolish mussel Numerous fossil species are known, the oldest dating to the Triassic.

Feeding

Mussels are filter feeders. They have two openings. The water enters the mantle cavity through the inflow opening, in which a permanent flow of water is generated by the eyelashes. The tiny food particles (plant and animal plankton) stick to the mucous layer of the gills. Then the eyelash hairs convey the mucus in the gills with the food particles to the mouth of the mussel and from there to the stomach and intestines, where the food is ultimately digested. The indigestible residues are expelled from the outflow opening with the respiratory water.

Reproduction

Each spring and summer, the females lay five to ten million eggs, which are then fertilized by the males. The fertilized egg cells become trochophoral larvae, 99.9 percent of which are eaten in the course of their four-week development into young mussels. Nevertheless, after this "selection" there are still around 10,000 young mussels left. These are about three millimeters in size and often drift around several hundred kilometers in the sea before they are about five centimeters in size in coastal regions with their byssus threads. The reason mussels live in such large colonies (also called banks) is because it gives the males a much greater chance of fertilizing eggs. After the larvae have developed freely floating as plankton for about four weeks, they attach themselves to stones, stakes, shill, sand and other mussels with byssus threads. They prefer the

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary ...

from estuaries and mud flats in the coastal regions.

Human use

''Mytilus''

s are widely exploited as food and used in

mariculture Mariculture, sometimes called marine farming or marine aquaculture, is a branch of aquaculture involving the cultivation of marine organisms for food and other animal products, in seawater. Subsets of it include ( offshore mariculture), fish fa ...

. For instance, in California, they have been consumed by coastal Native American people for almost 12 000 years.

Antimicrobial peptides Antimicrobial peptides (AMPs), also called host defence peptides (HDPs) are part of the innate immune response found among all classes of life. Fundamental differences exist between Prokaryote, prokaryotic and eukaryota, eukaryotic cells that may ...

called Mytilin A and B have been isolated from ''M. galloprovincialis'' and ''M. edulis''.

References

* J. H McDonald, R. Seed and R.K. Koehn (1991
Allozymes and morphometric characters of three species of ''Mytilus'' in the Northern and Southern Hemispheres
''Marine Biology'' 111: 323-333. Bivalve genera Taxa named by Carl Linnaeus Extant Jurassic first appearances {{Mytilidae-stub