77-453: Pteriomorphia (marine mussels) Palaeoheterodonta (freshwater mussels) Heterodonta ( zebra mussels ) 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 word "mussel"
154-1068: A FAO study. Within Europe, where mussels have been cultivated for centuries, Spain remained the industry leader. Aquaculture of mussels in North America began in the 1970s. In the US, the northeast and northwest have significant mussel aquaculture operations, where Mytilus edulis (blue mussel) is most commonly grown. While the mussel industry in the US has increased, in North America, 80% of cultured mussels are produced in Prince Edward Island in Canada. In Washington state , an estimated 2.9 million pounds of mussels were harvested in 2010, valued at roughly $ 4.3M. In New Zealand, Perna canaliculus (the New Zealand green-lipped mussel), industry produces over 140,000 metric tons (150,000 short tons) annually and in 2009
231-461: A danger along some coastlines. For instance, mussels should be avoided during the warmer months along the west coast of the United States. This poisoning is usually due to a bloom of dinoflagellates (red tides), which contain toxins. The dinoflagellates and their toxin are harmless to mussels, even when concentrated by the mussel's filter feeding, but the concentrated toxins cause serious illness if
308-400: A filter-feeder due to its bill proportions being similar to those of shoveler ducks . It is unique in being a large, flightless marine animal, unlike the smaller still volant flamingos and prions. Traditionally, Ctenochasmatoidea as a group has been listed as filter-feeders, due to their long, multiple slender teeth, clearly well adapted to trap prey. However, only Pterodaustro showcases
385-466: A highly effective source of fertilizer and animal feed In the U.S., researchers are investigating potential to model the use of shellfish and seaweed for nutrient mitigation in certain areas of Long Island Sound. Bivalves are also largely used as bioindicators to monitor the health of an aquatic environment, either fresh- or seawater. Their population status or structure, physiology, behaviour, or their content of certain elements or compounds can reveal
462-517: A kind of rudimentary filter feeding, using their long, slender teeth to trap small fish, though probably lacking the pumping mechanism of Pterodaustro . In essence, their foraging mechanism was similar to that of modern young Platanista " dolphins ". Filter feeding habits are conspicuously rare among Mesozoic marine reptiles , the main filter feeding niche being seemingly instead occupied by pachycormid fish. However, some sauropsids have been suggested to have engaged in filter feeding. Henodus
539-454: A means to mitigate excess nutrients and complement traditional wastewater treatment programs. Out of 511 species assessed globally, 44% of freshwater mussels listed on the IUCN Red List are classified at some level of threatened. There are 297 known freshwater mussel taxa in the United States and Canada, which are home to the most diverse freshwater mussel fauna in the world, especially in
616-910: A new proposed classification system for the Bivalvia was published by Bieler, Carter & Coan revising the classification of the Bivalvia, including the subclass Pteriomorphia. However, the following taxonomy represents the current accepted arrangement of this subclass according to the World Register of Marine Species Subclass: Pteriomorphia (Ark shells and bittersweet shells) (True oysters and their allies) (Scallops and their allies) (File shells and their allies) (Saltwater mussels) (Winged oysters and their allies) Filter feeders Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters , food particles or smaller organisms ( bacteria , microalgae and zooplanktons ) suspended in water, typically by having
693-438: A proper pumping mechanism, having up-turned jaws and powerful jaw and tongue musculature. Other ctenochasmatoids lack these, and are now instead thought to have been spoonbill -like catchers, using their specialised teeth simply to offer a larger surface area. Tellingly, these teeth, while small and numerous, are comparatively unspecialised to the baleen-like teeth of Pterodaustro . Boreopterids are thought to have relied on
770-452: A speed of 6 cm per minute. However, because Leuconia has more than 2 million flagellated chambers whose combined diameter is much greater than that of the canals, water flow through chambers slows to 3.6 cm per hour. Such a flow rate allows easy food capture by the collar cells. Water is expelled through a single osculum at a velocity of about 8.5 cm/second: a jet force capable of carrying waste products some distance away from
847-465: A spicy, favored delicacy. In coastal Karnataka Bearys prepare special rice balls stuffed with spicy fried mussels and steamed, locally known as "pachilede pindi". Mussels can be smoked, boiled, steamed, roasted, barbecued or fried in butter or vegetable oil. They can be used in soups, salads and sauces. As with all shellfish , except shrimp, mussels should be checked to ensure they are still alive just before they are cooked; enzymes quickly break down
SECTION 10
#1732884749425924-563: A stock of butter and white wine. Fries and Belgian beer sometimes are accompaniments. A similar style of preparation is commonly found in the Rhineland where mussels are customarily served in restaurants with a side of dark bread in "months containing an R", that is between September and April. In the Netherlands, mussels are sometimes served fried in batter or breadcrumbs , particularly at take-out food outlets or informal settings. In France,
1001-725: A swarm gulping, while lowering their tongue so that the head's ventral grooves expand and vastly increase the amount of water taken in. Baleen whales typically eat krill in polar or subpolar waters during summers, but can also take schooling fish, especially in the Northern Hemisphere. All baleen whales except the gray whale feed near the water surface, rarely diving deeper than 100 m (330 ft) or for extended periods. Gray whales live in shallow waters feeding primarily on bottom-living organisms such as amphipods . Bivalves are aquatic molluscs which have two-part shells . Typically both shells (or valves) are symmetrical along
1078-424: A water current which is used for circulation. Dissolved gases are brought to cells and enter the cells via simple diffusion . Metabolic wastes are also transferred to the water through diffusion. Sponges pump remarkable amounts of water. Leuconia , for example, is a small leuconoid sponge about 10 cm tall and 1 cm in diameter. It is estimated that water enters through more than 80,000 incurrent canals at
1155-585: Is "an environmental management strategy by which nutrients are removed from an aquatic ecosystem through the harvest of enhanced biological production, including the aquaculture of suspension-feeding shellfish or algae". Nutrient removal by shellfish, which are then harvested from the system, has the potential to help address environmental issues including excess inputs of nutrients ( eutrophication ), low dissolved oxygen, reduced light availability and impacts on eelgrass, harmful algal blooms, and increases in incidence of paralytic shellfish poisoning (PSP). For example,
1232-446: Is 1.0% N and 0.1% P. When the mussels are harvested and removed, these nutrients are also removed from the system and recycled in the form of seafood or mussel biomass, which can be used as an organic fertilizer or animal feed-additive. These ecosystem services provided by mussels are of particular interest to those hoping to mitigate excess anthropogenic marine nutrients, particularly in eutrophic marine systems. While mussel aquaculture
1309-421: Is 2-3mm. The seed is then typically reared in a nursery environment, where it is transferred to a material with a suitable surface for later relocation to the growing area. After about three months in the nursery, mussel seed is "socked" (placed in a tube-like mesh material) and hung on longlines or rafts for grow-out. Within a few days, the mussels migrate to the outside of the sock for better access food sources in
1386-403: Is accomplished through filter feeding, using the krill's developed front legs, providing for a very efficient filtering apparatus: the six thoracopods form a very effective "feeding basket" used to collect phytoplankton from the open water. In the animation at the top of this page, the krill is hovering at a 55° angle on the spot. In lower food concentrations, the feeding basket is pushed through
1463-507: Is actually promoted in some countries such as Sweden as a water management strategy to address coastal eutrophication, mussel farming as a nutrient mitigation tool is still in its infancy in most parts of the world. Ongoing efforts in the Baltic Sea (Denmark, Sweden, Germany, Poland) and Long Island Sound and Puget Sound in the U.S. are currently examining nutrient uptake, cost-effectiveness, and potential environmental impacts of mussel farming as
1540-408: Is continuously secreted by the mantle; the prismatic layer, a middle layer of chalky white crystals of calcium carbonate in a protein matrix; and the periostracum , an outer pigmented layer resembling a skin. The periostracum is composed of a protein called conchin , and its function is to protect the prismatic layer from abrasion and dissolution by acids (especially important in freshwater forms where
1617-455: Is frequently used to mean the bivalves of the marine family Mytilidae , most of which live on exposed shores in the intertidal zone, attached by means of their strong byssal threads ("beard") to a firm substrate. A few species (in the genus Bathymodiolus ) have colonised hydrothermal vents associated with deep ocean ridges. In most marine mussels the shell is longer than it is wide, being wedge-shaped or asymmetrical. The external colour of
SECTION 20
#17328847494251694-406: Is to detect and respond to predators. As such, pteriomorphia respond to the presence of a shadow by retracting their siphon , adduction, digging, or some combination of the three. Beyond this shadow response, however, pteriomorphia typically do not respond to other visual stimuli. Pteriomorphia have much higher rates of eye loss than eye gain and studying eye loss and gain can yield insights into
1771-602: Is very popular among tourists and low classes, probably because of the hot climate that favours mussels reproduction. In India, mussels are popular in Kerala , Maharashtra , Karnataka - Bhatkal , and Goa . They are either prepared with drumsticks , breadfruit or other vegetables, or filled with rice and coconut paste with spices and served hot. Fried mussels ('Kadukka' കടുക്ക in Malayalam ) of north Kerala especially in Thalassery are
1848-461: The Éclade des Moules , or, locally, Terré de Moules , is a mussel bake that can be found along the beaches of the Bay of Biscay . In Italy, mussels are mixed with other seafood; they are most commonly eaten steamed, sometimes with white wine, herbs, and served with the remaining water and some lemon. In Spain, they are consumed mostly steamed, sometimes boiling white wine, onion and herbs, and served with
1925-590: The Arcida , Ostreida , Pectinida , Limida , Mytilida , and Pteriida . It also contains some extinct and probably basal families , such as the Evyanidae , Colpomyidae , Bakevelliidae , Cassianellidae , and Lithiotidae . This subclass of molluscs has lamellibranch gills , and is epibenthic . Some attach to the substrate using a byssus . The foot is reduced. The mantle margins are not fused. Gills are usually large and assist in feeding. This group includes
2002-481: The Atlantic menhaden , a type of herring , lives on plankton caught in midwater. Adult menhaden can filter up to four gallons of water a minute and play an important role in clarifying ocean water. They are also a natural check to the deadly red tide . In addition to these bony fish, four types of cartilaginous fishes are also filter feeders. The whale shark sucks in a mouthful of water, closes its mouth and expels
2079-471: The Cetacea (whales, dolphins, and porpoises), are characterized by having baleen plates for filtering food from water, rather than teeth. This distinguishes them from the other suborder of cetaceans, the toothed whales (Odontoceti). The suborder contains four families and fourteen species. Baleen whales typically seek out a concentration of zooplankton, swim through it, either open-mouthed or gulping, and filter
2156-544: The eggs develop into a larval stage called a glochidium (plural glochidia), which temporarily parasitizes fish, attaching themselves to the fish's fins or gills. Prior to their release, the glochidia grow in the gills of the host fish where they are constantly flushed with oxygen-rich water. In some species, release occurs when a fish attempts to attack the mussel's mantle flaps, which are shaped like minnows or other prey, an example of aggressive mimicry . Glochidia are generally species-specific, and will only live if they find
2233-554: The vertebrates . Nearly all tunicates are suspension feeders , capturing planktonic particles by filtering sea water through their bodies. Water is drawn into the body through the inhalant buccal siphon by the action of cilia lining the gill slits. The filtered water is then expelled through a separate exhalant siphon. To obtain enough food, a typical tunicate needs to process about one body-volume of water per second. Flamingos filter-feed on brine shrimp . Their oddly shaped beaks are specially adapted to separate mud and silt from
2310-441: The "bray" or boiling water as a supplementary hot drink. In Cantonese cuisine , mussels are cooked in a broth of garlic and fermented black bean. In New Zealand, they are served in a chilli or garlic-based vinaigrette , processed into fritters and fried, or used as the base for a chowder . In Brazil, it is common to see mussels being cooked and served with olive oil, usually accompanied by onion, garlic and other herbs. The plate
2387-575: The United States during the Second World War , mussels were commonly served in diners and restaurants across the country. This was due to wartime rationing and shortages of red meat, such as beef and pork. Mussels became a popular substitute for most meats (with the exception of poultry). In Belgium, the Netherlands, and France, mussels are consumed with French fries ( mosselen met friet or moules-frites ) or bread. In Belgium, mussels are sometimes served with fresh herbs and flavorful vegetables in
Mussel - Misplaced Pages Continue
2464-420: The average harvested mussel contains: 0.8–1.2% nitrogen and 0.06–0.08% phosphorus Removal of enhanced biomass can not only combat eutrophication and also support the local economy by providing product for animal feed or compost. In Sweden, environmental agencies utilize mussel farming as a management tool in improving water quality conditions, where mussel bioextraction efforts have been evaluated and shown to be
2541-495: The beating of cilia . Suspended food ( phytoplankton , zooplankton , algae and other water-borne nutrients and particles) are trapped in the mucus of a gill, and from there are transported to the mouth, where they are eaten, digested and expelled as feces or pseudofeces . Each oyster filters up to five litres of water per hour. Scientists believe that the Chesapeake Bay 's once-flourishing oyster population historically filtered
2618-414: The body, with a larval stage that drifts for three weeks to six months, before settling on a hard surface as a young mussel. There, it is capable of moving slowly by means of attaching and detaching byssal threads to attain a better life position. Freshwater mussels reproduce sexually. Sperm is released by the male directly into the water and enters the female via the incurrent siphon. After fertilization,
2695-926: The case of the buoy barnacle ) depending on the species and the niches they have evolved to occupy. Extant species that rely on such method of feeding encompass numerous phyla , including poriferans ( sponges ), cnidarians ( jellyfish , sea pens and corals ), arthropods ( krill , mysids and barnacles ), molluscs ( bivalves , such as clams , scallops and oysters ), echinoderms ( sea lilies ) and chordates ( lancelets , sea squirts and salps , as well as many marine vertebrates such as most species of forage fish , American paddlefish , silver and bighead carps , baleen whales , manta ray and three species of sharks —the whale shark , basking shark and megamouth shark ). Some water birds such as flamingos and certain duck species, though predominantly terrestrial, are also filter feeders when foraging . Most forage fish are filter feeders. For example,
2772-469: The complete absence of eyes in deep sea species. The cladogram is based on molecular phylogeny using mitochondrial (12S, 16S) and nuclear (18S, 28S, and H3) gene markers by Yaron Malkowsky and Annette Klussmann-Kolb in 2012. Palliolinae (in part) Palliolinae (in part) and Camptonectinae Chlamydinae (70 mya) Pecten Flexopecten (247 mya) Aequipecten Limidae (file shells) other Pteriomorphia ( oysters , mussels ) In 2010
2849-443: The construction of artificial tendons. Mussels are widely used as bio-indicators to monitor the health of aquatic environments in both fresh water and the marine environments. They are particularly useful since they are distributed worldwide and they are sessile. These characteristics ensure that they are representative of the environment where they are sampled or placed. Their population status or structure, physiology, behaviour or
2926-562: The contamination status of any aquatic ecosystem. They are useful as they are sessile, which means they are closely representative of the environment where they are sampled or placed (caging), and they breathe water all the time, exposing their gills and internal tissues: bioaccumulation . One of the most famous projects in that field is the Mussel Watch Programme in America. Sponges have no true circulatory system ; instead, they create
3003-432: The correct fish host. Once the larval mussels attach to the fish, the fish body reacts to cover them with cells forming a cyst , where the glochidia remain for two to five weeks (depending on temperature). They grow, break free from the host, and drop to the bottom of the water to begin an independent life. Marine mussels are eaten by humans, starfish , seabirds, and by numerous species of predatory marine gastropods in
3080-444: The decay of leaf materials produces acids). Like most bivalves, mussels have a large organ called a foot . In freshwater mussels, the foot is large, muscular, and generally hatchet-shaped. It is used to pull the animal through the substrate (typically sand, gravel, or silt) in which it lies partially buried. It does this by repeatedly advancing the foot through the substrate, expanding the end so it serves as an anchor, and then pulling
3157-540: The design of peptide mimics that were well studied for surface bioengineering of medical implants. Self-assembling mussel-inspired peptides were also shown to form functional nanostructures. Also, a peptide derived from mussel foot protein-5, a key protein in mussel adhesion, displayed antibacterial properties and served as inspiration for the design of a new class of peptide-based antibacterial adhesive hydrogels, which are active against drug-resistant Gram-positive bacteria. Additionally byssal threads have provided insight into
Mussel - Misplaced Pages Continue
3234-428: The enlarged lower lip which fits onto the bowed upper jaw. As the right whale swims, a front gap between the two rows of baleen plates lets the water in together with the prey, while the baleens filter out the water. Rorquals such as the blue whale , in contrast, have smaller heads, are fast swimmers with short and broad baleen plates. To catch prey, they widely open their lower jaw — almost 90° — swim through
3311-461: The estuary's entire water volume of excess nutrients every three or four days. Today that process would take almost a year, and sediment, nutrients, and algae can cause problems in local waters. Oysters filter these pollutants, and either eat them or shape them into small packets that are deposited on the bottom where they are harmless. Bivalve shellfish recycle nutrients that enter waterways from human and agricultural sources. Nutrient bioextraction
3388-507: The family Dreissenidae are not related to previously mentioned groups, even though they resemble many Mytilus species in shape, and live attached to rocks and other hard surfaces in a similar manner, using a byssus. They are classified with the Heterodonta , the taxonomic group which includes most of the bivalves commonly referred to as "clams". The mussel's external shell is composed of two hinged halves or "valves". The valves are joined on
3465-736: The family Muricidae , such as the dog whelk , Nucella lapillus . Freshwater mussels are eaten by muskrats , otters , raccoons , ducks, baboons , humans, and geese. Marine mussels are abundant in the low and mid intertidal zone in temperate seas globally. Other species of marine mussel live in tropical intertidal areas, but not in the same huge numbers as in temperate zones. Certain species of marine mussels prefer salt marshes or quiet bays, while others thrive in pounding surf, completely covering wave-washed rocks. Some species have colonized abyssal depths near hydrothermal vents . The South African white mussel exceptionally does not bind itself to rocks but burrows into sandy beaches extending two tubes above
3542-507: The filter between the gill bars is swallowed. Whale sharks have been observed "coughing" and it is presumed that this is a method of clearing a build up of food particles in the gill rakers. The megamouth shark has luminous organs called photophores around its mouth. It is believed they may exist to lure plankton or small fish into its mouth. The basking shark is a passive filter feeder, filtering zooplankton , small fish, and invertebrates from up to 2,000 tons of water per hour. Unlike
3619-515: The food into the mouth, where digestion begins. Marine mussels are usually found clumping together on wave-washed rocks, each attached to the rock by its byssus. The clumping habit helps hold the mussels firm against the force of the waves. At low tide mussels in the middle of a clump will undergo less water loss because of water capture by the other mussels. Both marine and freshwater mussels are gonochoristic , with separate male and female individuals. In marine mussels, fertilization occurs outside
3696-411: The food they eat, and are uniquely used upside-down. The filtering of food items is assisted by hairy structures called lamellae which line the mandibles , and the large rough-surfaced tongue. Prions are specialised petrels with filter-feeding habits. Their name comes from their saw-like jaw edges, used to scope out small planktionic animals. The extinct swan Annakacygna is speculated to be
3773-739: The grow-out area and the rearing method being used. Dredges are currently used for on-bottom culture. Mussels grown on wooden poles can be harvested by hand or with a hydraulic powered system. For raft and longline culture, a platform is typically lowered under the mussel lines, which are then cut from the system and brought to the surface and dumped into containers on a nearby vessel. After harvest, mussels are typically placed in seawater tanks to rid them of impurities before marketing. Byssal threads, used to anchor mussels to substrates, are now recognized as superior bonding agents. A number of studies have investigated mussel "glues" for industrial and surgical applications. Further, mussel adhesive proteins inspired
3850-662: The highest species diversity in Southeast Asia), and 33 in Australasia. The species in these areas are not as well researched as in North America and Europe. Approximately 61% of freshwater mussels in Asia had not been assessed and conservation efforts were almost non-existent. No Asian mussels were protected internationally under legislation such as CITES . The main factors contributing to the decline of freshwater mussels include destruction by dams, increased siltation, channel alteration and
3927-448: The hinge line. The class has 30,000 species , including scallops , clams , oysters and mussels . Most bivalves are filter feeders (although some have taken up scavenging and predation), extracting organic matter from the sea in which they live. Nephridia , the shellfish version of kidneys , remove the waste material. Buried bivalves feed by extending a siphon to the surface. For example, oysters draw water in over their gills through
SECTION 50
#17328847494254004-500: The introduction of invasive species such as the zebra mussel . Humans have used mussels as food for thousands of years. About 17 species are edible, of which the most commonly eaten are Mytilus edulis , M. galloprovincialis , M. trossulus and Perna canaliculus . Although freshwater mussels are edible, today they are widely considered unpalatable and are rarely consumed. Freshwater mussels were once eaten extensively by native peoples of North America and some still do today. In
4081-522: The level of contamination with elements or compounds can indicate the status of the ecosystem. Transplanted caged mussel were used in a study to monitor heavy metal contamination in coastal waters. Marine nutrient bioextraction is the practice of farming and harvesting marine organisms such as shellfish and seaweed for the purpose of reducing nutrient pollution . Mussels and other bivalve shellfish consume phytoplankton containing nutrients such as nitrogen (N) and phosphorus (P). On average, one live mussel
4158-399: The meat and make them unpalatable or poisonous after dying or uncooked. Some mussels might contain toxins. A simple criterion is that live mussels, when in the air, will shut tightly when disturbed. Open, unresponsive mussels are dead, and must be discarded. Unusually heavy, wild-caught, closed mussels may be discarded as they may contain only mud or sand. (They can be tested by slightly opening
4235-490: The mechanisms behind convergent evolution and the evolution and regression of complex traits. Eyes evolved exclusively in epifaunal lineages, and have been lost in some lineages that adopted infaunal and semi-infaunal lifestyles, suggesting a correlation between eye loss and adoption of infaunal or semi-infaunal lifestyles. Additionally, eyes in Pectinidae exhibit a reduction in functionality as habitat depth increases, ending in
4312-413: The megamouth and whale sharks, the basking shark does not appear to actively seek its quarry; but it does possess large olfactory bulbs that may guide it in the right direction. Unlike the other large filter feeders, it relies only on the water that is pushed through the gills by swimming; the megamouth shark and whale shark can suck or pump water through their gills. Manta rays can time their arrival at
4389-450: The mussel has opened. Both marine and freshwater mussels are filter feeders ; they feed on plankton and other microscopic sea creatures which are free-floating in seawater. A mussel draws water in through its incurrent siphon . The water is then brought into the branchial chamber by the actions of the cilia located on the gills for ciliary-mucus feeding. The wastewater exits through the excurrent siphon. The labial palps finally funnel
4466-411: The mussel to its substrate allowing it to remain sessile in areas of high flow. The byssal thread is also sometimes used by mussels as a defensive measure, to tether predatory molluscs, such as dog whelks , that invade mussel beds, immobilising them and thus starving them to death. In cooking, the byssus of the mussel is known as the "beard" and is removed during preparation, often after cooking when
4543-476: The mussels are consumed by humans, including paralytic shellfish poisoning . Foods that are an "excellent source" of a particular nutrient provide 20% or more of the recommended daily value . Foods that are a "good source" of a particular nutrient provide between 10 and 20% of the recommended daily value. Pteriomorphia The Pteriomorphia comprise a subclass of saltwater clams, marine bivalve molluscs . It contains several major orders, including
4620-427: The outside by a ligament, and are closed when necessary by strong internal muscles (anterior and posterior adductor muscles). Mussel shells carry out a variety of functions, including support for soft tissues, protection from predators and protection against desiccation. The shell has three layers. In the pearly mussels there is an inner iridescent layer of nacre (mother-of-pearl) composed of calcium carbonate , which
4697-500: The prey from the water using their baleens. A baleen is a row of a large number of keratin plates attached to the upper jaw with a composition similar to those in human hair or fingernails. These plates are triangular in section with the largest, inward-facing side bearing fine hairs forming a filtering mat. Right whales are slow swimmers with large heads and mouths. Their baleen plates are narrow and very long — up to 4 m (13 ft) in bowheads — and accommodated inside
SECTION 60
#17328847494254774-710: The remaining water and some lemon. They can also be eaten as tigres , a sort of croquette using the mussel meat, shrimps and other pieces of fish in a thick bechamel then breaded and fried in the clean mussel shell. They are used in other sort of dishes such as rices or soups or commonly eaten canned in a pickling brine made of oil, vinegar, peppercorns, bay leaves and paprika. In Turkey, mussels are either covered with flour and fried on skewers ( midye tava ), or filled with rice and served cold ( midye dolma ) and are usually consumed after alcohol (mostly raki or beer). They are used in Ireland boiled and seasoned with vinegar, with
4851-442: The rest of the animal with its shell forward. It also serves as a fleshy anchor when the animal is stationary. In marine mussels, the foot is smaller, tongue-like in shape, with a groove on the ventral surface which is continuous with the byssus pit. In this pit, a viscous secretion is exuded, entering the groove and hardening gradually upon contact with sea water. This forms extremely tough, strong, elastic, byssal threads that secure
4928-423: The sand surface for ingestion of food and water and exhausting wastes. Freshwater mussels inhabit permanent lakes, rivers, canals and streams throughout the world except in the polar regions. They require a constant source of cool, clean water. They prefer water with a substantial mineral content, using calcium carbonate to build their shells. In 2005, China accounted for 40% of the global mussel catch according to
5005-416: The sea floor, constantly collecting particles with their filter basket. They are an important food source for herring , cod , flounder , and striped bass . Mysids have a high resistance to toxins in polluted areas, and may contribute to high toxin levels in their predators. Antarctic krill manages to directly utilize the minute phytoplankton cells, which no other higher animal of krill size can do. This
5082-740: The shell halves.) A thorough rinse in water and removal of "the beard" is suggested. Mussel shells usually open when cooked, revealing the cooked soft parts. Historically, it has been believed that after cooking all the mussels should have opened and those that have not are not safe to eat and should be discarded. However, according to marine biologist Nick Ruello, this advice may have arisen from an old, poorly researched cookbook's advice, which has now become an assumed truism for all shellfish. Ruello found 11.5% of all mussels failed to open during cooking, but when forced open, 100% were "both adequately cooked and safe to eat." Although mussels are valued as food, mussel poisoning due to toxic planktonic organisms can be
5159-461: The shell is often dark blue, blackish, or brown, while the interior is silvery and somewhat nacreous . The common name "mussel" is also used for many freshwater bivalves, including the freshwater pearl mussels . Freshwater mussel species inhabit lakes, ponds, rivers, creeks, canals, and they are classified in a different subclass of bivalves, despite some very superficial similarities in appearance. Freshwater zebra mussels and their relatives in
5236-810: The southeastern United States. Of the 297 known species, 213 (71.7%) taxa are listed as endangered, threatened, or of special concern. Approximately 37 North American species were considered extinct in 2004. Out of 16 recognized freshwater mussel species in Europe, 12 are considered threatened, with varying statuses from Near Threatened to Critically Endangered. 8 species are protected by the European Union Habitats Directive across all annexes. There are approximately 85 known species in Africa, 102 in Central America, 74 in South America, 228 in Asia (with
5313-431: The spawning of large shoals of fish and feed on the free-floating eggs and sperm. This stratagem is also employed by whale sharks. Like all arthropods, crustaceans are ecdysozoans , a clade without cilia . Cilia play an important role for many filter feeding animals, but because crustaceans don't have them, they need to use modified extremities for filter feeding instead. Mysidaceans live close to shore and hover above
5390-407: The sponge. The moon jellyfish has a grid of fibres which are slowly pulled through the water. The motion is so slow that copepods cannot sense it and do not react with an escape response . Other filter-feeding cnidarians include sea pens , sea fans , plumose anemones , and Xenia . Tunicates , such as ascidians , salps and sea squirts , are chordates which form a sister group to
5467-443: The water column. Mussels grow quickly and are usually ready for harvest in less than two years. Unlike other cultured bivalves, mussels use byssus threads (beard) to attach themselves to any firm substrate, which makes them suitable for a number of culture methods. There are a variety of techniques for growing mussels. In roughly 12–15 months, mussels reach marketable size (40mm) and are ready for harvest. Harvesting methods depend on
5544-749: The water for over half a meter in an opened position, and then the algae are combed to the mouth opening with special setae on the inner side of the thoracopods. Porcelain crabs have feeding appendages covered with setae to filter food particles from the flowing water. Most species of barnacles are filter feeders, using their highly modified legs to sift plankton from the water. Also some insects with aquatic larvae or nymphs are filter feeders during their aquatic stage. Such as some species of mayfly nymphs, mosquito larvae, and black fly larvae. Instead of using modified limbs or mouthparts, some caddisfly larvae produce nets of silk used for filter feeding. The baleen whales (Mysticeti), one of two suborders of
5621-504: The water pass over or through a specialized filtering organ that sieves out and/or traps solids. Filter feeders can play an important role in condensing biomass and removing excess nutrients (such as nitrogen and phosphate ) from the local waterbody , and are therefore considered water-cleaning ecosystem engineers . They are also important in bioaccumulation and, as a result, as indicator organisms . Filter feeders can be sessile , planktonic , nektonic or even neustonic (in
5698-428: The water through its gills . During the slight delay between closing the mouth and opening the gill flaps, plankton is trapped against the dermal denticles which line its gill plates and pharynx . This fine sieve-like apparatus, which is a unique modification of the gill rakers, prevents the passage of anything but fluid out through the gills (anything above 2 to 3 mm in diameter is trapped). Any material caught in
5775-546: The well known mussels , scallops , pen shells , and oysters . It also includes the only members of the class bivalvia to have rudimentary eyes. Pteriomorphian bivalves possess five types of photoreceptors, each evolving independently and each associated with different clades within Pteriomorphia. There are cap eyespots, pigmented cups, compound eyes , concave mirror eyes, and invaginated eyes, each having evolved independently. The primary purpose of pteriomorphian eyes
5852-454: Was a placodont with unique baleen-like denticles and features of the hyoid and jaw musculature comparable to those of flamingos. Combined with its lacustrine environment, it might have occupied a similar ecological niche. In particular, it was probably a herbivore , filtering out algae and other small-sized flora from the substrates. Stomatosuchidae is a family of freshwater crocodylomorphs with rorqual-like jaws and minuscule teeth, and
5929-721: Was valued in excess of NZ$ 250 million. Freshwater mussels are used as host animals for the cultivation of freshwater pearls . Some species of marine mussel, including the blue mussel ( Mytilus edulis ) and the New Zealand green-lipped mussel ( Perna canaliculus ), are also cultivated as a source of food. In some areas of the world, mussel farmers collect naturally occurring marine mussel seed for transfer to more appropriate growing areas, however, most North American mussel farmers rely on hatchery-produced seed. Growers typically purchase seed after it has set (about 1mm in size) or after it has been nursed in upwellers for 3-6 additional weeks and
#424575