Mytilus (genus)
Mussels from the side, from below and opened with durchtrenntem sphincter
- M. edulis ( Common mussel )
- M. galloprovincialis ( Mediterranean mussel )
- M. trossulus ( Pacific mussel )
Mussels (Mytilus ), of Middle High German mies for, Moss ', also known as mussels, are a cosmopolitan species of mussels ( Bivalvia ). After the larvae have about four weeks free floating developed as plankton, fasten with byssus to rocks, piles, Schill and hard sand. Here, they prefer the brackish water of estuaries and tidal flats in the coastal regions. Mussels have a gray to blue-violet, about 5 to 10 inches long shell of elongated oval shape.
- 8.1 Literature
- 8.2 Notes and references
- 8.3 External links
Physique
Mussels are 5 to 10 cm long and follow the general plan of the mussels. They consist of a right and left half-shell, held together with an elastic band lock ( ligament ). The shell consists of three layers: the top cladding layer of organic material ( periostracum ), the middle thick layer of lime ( Ostracum ) and the innermost, precious, silver-white lustrous nacre ( hypostracum ). In the mantle cavity of the mussel are two strong blood gills with gill leaves. A muscular foot located between the gills with the byssus gland. This gland is using contained in the mussel protein and iron filtered out of the sea, the byssus threads ago, with which they can hold anywhere. Mussels also have a sphincter, which is located in the soft part of the shell, as well as other organs (heart, stomach, intestines, kidneys). With the help of the sphincter, the mussel can close in case of danger or drought.
Nutrition
The mussel is a filter feeder. It has two openings. The water enters through the inlet opening into the mantle cavity in which the cilia a permanent water current is generated. So the tiny food particles ( plant and animal plankton) stick to the mucus layer of the gills, and the gills filter at the same time the oxygen contained in the water. The carbon dioxide is released back into the water. Then the cilia promote the mucus of the gills with the food particles to the mouth of the mussel and from there into the stomach and intestine where the food is ultimately digested. The indigestible residues are discharged from the exhaust port with the breath water.
Reproduction
Every spring and summer, females lay from five to ten million eggs which are then fertilized by the males. The fertilized eggs are Trochophoralarven that are eaten in the course of their four-week development of young mussel to 99.9 percent. Nevertheless, although after this "elite" still about 10,000 young mussels left. These are about three millimeters in size and often drive still several hundred kilometers in the sea around before they get stuck with a size of about five centimeters in coastal regions with their byssus threads. The reason why mussels live in such large colonies (also called banks ) is that the opportunity for males to fertilize eggs, thus is much greater.
Enemies
Among the natural enemies include starfish and whelks, waiting for the opening of the shells and then eat the shell. Numerous vertebrates eat mussels, about walruses, fish such as flounder and plaice, herring gulls, oystercatchers and ducks.
From people they may only be fished according to strict specifications and from specially designated aquaculture. Mussels are not only fished for human consumption, they also serve as fertilizer, fishing bait, feed for aquarium fish and sometimes also for the attachment of gravelly shores, as in the English county of Lancashire.
2011 announced the conservation station Wadden Sea National Park Schleswig -Holstein Wadden Sea there are obviously fewer mussels. Even the protected resources on the tidal flats had declined by 79 percent over the course of 20 years.
Mild winters make the situation worse, because then the predators of juvenile mussels - such as starfish, snails or birds - are almost always present.
Self-protection
The shell of the mussel is used for protection, they can be jerky closed at risk with the sphincter. Thus, the mussel persist for weeks. The Adriatic Blue mussel Mytilus galloprovincialis as a defense substance produced toxic Oxazinine.
Mussels as food
Some mussel species are the most important edible clams from the oyster. These mainly include the occurring in the Atlantic, North Sea and Baltic Mytilus edulis and Mytilus galloprovincialis of the Atlantic and the Mediterranean (see mussels from Galicia ). Since the 13th century, they are bred in France in cultures of wooden pegs, in Galicia mussels are known since the settlement by the Celts. Today, they are cultivated on the Dutch, German and Italian coast. Every year, around 550,000 tonnes of mussels in Europe in the trade, around 250,000 tonnes of Mytilus galloprovincialis and belong to the genus are from the aquaculture in Galicia.
A common preparation variant mussels Rhenish Art in Belgium and northern France, mussels are often served with french fries as moules - frites.
Mussels can lead to shellfish poisoning in lack of medical checks in rare cases when they have eaten poisonous plankton to humans; a few people are also allergic to their protein and therefore also react with symptoms of poisoning. Before cooking the mussels must still be alive, so keep it closed its case or close it if it is knocked out. Stay open, they should be discarded. Mussels that remain closed after cooking, are also considered inedible, and this statement is, however, doubted.
Mytilus edulis
The Mytilus edulis (Latin edulis edible = ), an edible mussel is called in Northern Europe as the blue mussel. Characteristic are the black-blue- purple surface and oval shape. The clam can grow up to a size of 10 cm. Usually they populated the seas and bays and is found in brackish water as in salt water.
Pictures
Mussels on the beach
Mussel shells on a beach in Iceland
Mejillones escabechados