Perna perna
Encyclopedia
The brown mussel, Perna perna, is an economically important mussel
, a bivalve mollusc belonging to the family
Mytilidae
. It is harvested as a food source but is also known to harbor toxins and cause damage to marine structures. It is native to the waters of Africa
, Europe
, and South America
and was introduced in the waters of North America
.
Similar species include the European mussel, Mytilus galloprovincialis, and the black mussel, Choromytilus meridionalis. The European mussel is similar in shape and color to the brown mussel and shares its native habitat on the south-western coast of Africa. The European mussel is also more resistant to human disturbance such as use for baits and consumption. It is out-competing the brown mussel as it is more resistant to certain parasites. The black mussel has similar shape and size although it lacks the distinguishable pitted resillal ridge.
The brown mussel can also be mistaken for the more famous greenish-brown species Perna viridis
, as their color and shell shape can change depending on environmental conditions.
. It is found in waters off the west coast of Africa and the coast of South America up to the Caribbean
. It is accidentally introduced as an invasive species
to the coast of Texas
via the boat hulls
and water ballasts of ships from Venezuela
. Its distribution include: Chile, Peru, South Africa.
The brown mussel naturally colonizes rocky shores but can also attach to submerged man-made objects such as navigation buoys, petroleum platforms and shipwrecks. The adult brown mussel can tolerate a temperature range of 10 to 30°C and a salinity
range of about 15 to 50 ppt
. Its colonization of the hard strata improves that surface's marine ecology. The colonization increases surface area, encouraging other marine organisms such as limpet
s, polychaete
s, barnacle
s, snail
s and algae to settle there as well.
during the spawning season between May and October although this is also reported to occur in December. The two sexes release eggs and sperm to the water during spawning to produce veliger
larvae. Fifteen hours after fertilization the larvae have well-developed hinge teeth. Ten to twelve days after fertilization the larvae undergo metamorphosis
where byssal threads are secreted. The larvae then settle on rocky surfaces.
The brown mussel is a filter feeder
and feeds on phytoplankton
, zooplankton
and suspended organic materials. It is plagued by the parasite Proctoeces maculatus and an unidentified bucephalid sporocyst which castrates
both sexes. On the African coastline it is preyed upon by the whelk Nucella cingulata, lobster
s, octopus
es, gulls and the African Black Oystercatcher
. On the South American coastline, it provides food for Callinectes danae
, Cymatium parthenopeun, Chicoreus brevifrons
, Thais haemastoma, and Menippe nodifroms.
from consumed dinoflagellate
s. Its consumption has caused outbreaks of Paralytic Shellfish Poisoning
in Venezuela
.
The brown mussel is known to aggregate in such large amounts that it is able to sink navigational buoys
. It also coexists with the Asian green mussel in fouling water pipes and marine equipment. It is less resistant to chlorination
than Perna viridis
and thus easier to control. However, it is recommended that the concentration of chlorine used for chlorination be above the tolerance level of Perna viridis, the tougher of the two biofouling mussels.
Mussel
The common name mussel is used for members of several families of clams or bivalvia mollusca, 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...
, a bivalve mollusc belonging to the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Mytilidae
Mytilidae
Mytilidae is a family of small to large saltwater mussels, marine bivalve mollusks in the order Mytiloida. It is the only family in the order...
. It is harvested as a food source but is also known to harbor toxins and cause damage to marine structures. It is native to the waters of Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
and was introduced in the waters of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Description
Perna perna is usually 90 mm long although it can reach sizes of up to 120 mm. The mussel is easily recognized by its brown color but its identifying characteristic is the "divided posterior retractor mussel scar". Its pitted resillal ridge also differentiates the mussel from other bivalves.Similar species include the European mussel, Mytilus galloprovincialis, and the black mussel, Choromytilus meridionalis. The European mussel is similar in shape and color to the brown mussel and shares its native habitat on the south-western coast of Africa. The European mussel is also more resistant to human disturbance such as use for baits and consumption. It is out-competing the brown mussel as it is more resistant to certain parasites. The black mussel has similar shape and size although it lacks the distinguishable pitted resillal ridge.
The brown mussel can also be mistaken for the more famous greenish-brown species Perna viridis
Perna viridis
The Asian green mussel , also known as the Philippine green mussel, is an economically important mussel, a bivalve belonging to the family Mytilidae. It is harvested for food but is also known to harbor toxins and cause damage to submerged structures such as drainage pipes...
, as their color and shell shape can change depending on environmental conditions.
Habitat and distribution
The brown mussel is native to the tropical and sub-tropical regions of the Atlantic OceanAtlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. It is found in waters off the west coast of Africa and the coast of South America up to the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
. It is accidentally introduced as an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
to the coast of Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
via the boat hulls
Biofouling
Biofouling or biological fouling is the undesirable accumulation of microorganisms, plants, algae, or animals on wetted structures.-Impact:...
and water ballasts of ships from Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
. Its distribution include: Chile, Peru, South Africa.
The brown mussel naturally colonizes rocky shores but can also attach to submerged man-made objects such as navigation buoys, petroleum platforms and shipwrecks. The adult brown mussel can tolerate a temperature range of 10 to 30°C and a salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
range of about 15 to 50 ppt
Parts-per notation
In science and engineering, the parts-per notation is a set of pseudo units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement...
. Its colonization of the hard strata improves that surface's marine ecology. The colonization increases surface area, encouraging other marine organisms such as limpet
Limpet
Limpet is a common name for a number of different kinds of saltwater and freshwater snails ; it is applied to those snails that have a simple shell which is more or less conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snails.The name limpet is most...
s, polychaete
Polychaete
The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...
s, barnacle
Barnacle
A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
s, snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s and algae to settle there as well.
Ecology and life history
The mussel utilizes external fertilizationExternal fertilization
External fertilization is a form of fertilization in which a sperm cell is united with an egg cell external to the bodies of the reproducing individuals. In contrast, internal fertilization takes place inside the female after insemination through copulation....
during the spawning season between May and October although this is also reported to occur in December. The two sexes release eggs and sperm to the water during spawning to produce veliger
Veliger
A veliger is the planktonic larva of many kinds of marine and freshwater gastropod molluscs, as well as most bivalve mollusks.- Description :...
larvae. Fifteen hours after fertilization the larvae have well-developed hinge teeth. Ten to twelve days after fertilization the larvae undergo metamorphosis
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
where byssal threads are secreted. The larvae then settle on rocky surfaces.
The brown mussel is a filter feeder
Filter feeder
Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...
and feeds on phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
, zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
and suspended organic materials. It is plagued by the parasite Proctoeces maculatus and an unidentified bucephalid sporocyst which castrates
Castration
Castration is any action, surgical, chemical, or otherwise, by which a male loses the functions of the testicles or a female loses the functions of the ovaries.-Humans:...
both sexes. On the African coastline it is preyed upon by the whelk Nucella cingulata, lobster
Lobster
Clawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...
s, octopus
Octopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
es, gulls and the African Black Oystercatcher
African Black Oystercatcher
The African Oystercatcher or African Black Oystercatcher, is a large wader which is a resident breeder on the rocky coasts and islands of southern Africa...
. On the South American coastline, it provides food for Callinectes danae
Callinectes danae
Callinectes danae is a species of swimming crab. The carapace is olive-brown and up to long; the walking legs are blue. The species is common in Brazil and the West Indies....
, Cymatium parthenopeun, Chicoreus brevifrons
Chicoreus brevifrons
Chicoreus brevifrons, common name the west indian murex, is a species of predatory sea snail, a marine gastropod mollusk in the family Muricidae, the murex snails. -Shell description:The maximum shell length of this species is up to 150 mm....
, Thais haemastoma, and Menippe nodifroms.
Importance to humans
Perna perna is harvested as a food source in Africa and South America. The bivalve is considered for cultivation as it can grow quickly to the commercial size of 60 to 80 mm in just 6 or 7 months. It is also well-suited to tropical and subtropical regions. However, the mussel can harbor saxitoxinSaxitoxin
Saxitoxin is a neurotoxin naturally produced by certain species of marine dinoflagellates and cyanobacteria Saxitoxin (STX) is a neurotoxin naturally produced by certain species of marine dinoflagellates (Alexandrium sp., Gymnodinium sp., Pyrodinium sp.) and cyanobacteria Saxitoxin (STX) is a...
from consumed dinoflagellate
Dinoflagellate
The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...
s. Its consumption has caused outbreaks of Paralytic Shellfish Poisoning
Paralytic shellfish poisoning
Paralytic shellfish poisoning is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks . These shellfish are filter feeders and, therefore, accumulate toxins produced by microscopic algae, such as...
in Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
.
The brown mussel is known to aggregate in such large amounts that it is able to sink navigational buoys
Sea mark
A sea mark, also seamark and navigation mark, is a form of aid to navigation and pilotage aid which identifies the approximate position of a maritime channel, hazard and administrative area to allow boats, ships and seaplanes to navigate safely....
. It also coexists with the Asian green mussel in fouling water pipes and marine equipment. It is less resistant to chlorination
Chlorination
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...
than Perna viridis
Perna viridis
The Asian green mussel , also known as the Philippine green mussel, is an economically important mussel, a bivalve belonging to the family Mytilidae. It is harvested for food but is also known to harbor toxins and cause damage to submerged structures such as drainage pipes...
and thus easier to control. However, it is recommended that the concentration of chlorine used for chlorination be above the tolerance level of Perna viridis, the tougher of the two biofouling mussels.