Perna viridis (Asian green mussel)
- Summary of Invasiveness
- Taxonomic Tree
- Distribution Table
- Habitat List
- Biology and Ecology
- Natural Food Sources
- Natural enemies
- Pathway Causes
- Pathway Vectors
- Impact Summary
- Economic Impact
- Environmental Impact
- Impact: Biodiversity
- Social Impact
- Uses List
- Links to Websites
- Distribution Maps
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PicturesTop of page
IdentityTop of page
Preferred Scientific Name
- Perna viridis Linnaeus, 1758
Preferred Common Name
- Asian green mussel
Other Scientific Names
- Chloromya smaragdinus Jukes-Browne, 1905
- Chloromya viridis Dodge, 1952
- Mytilus opalus Lamarck, 1819
- Mytilus smaragdinus Chemnitz, 1785
- Mytilus viridis Linnaeus, 1758
International Common Names
- English: green mussel; mussel, green
- Spanish: mejillón verde
- French: moule verte asiatique
Local Common Names
- India: green mussel
- Malaysia: green lipped mussel
- Philippines: Philippine green mussel; Philippine mussel
Summary of InvasivenessTop of page
P. viridis has been recognised as an invasive species since its introduction out of its native range around the world through ship ballast and hull fouling, mainly into the Caribbean and western Atlantic. This species can quickly form dense colonies in a range of environmental conditions. It has the ability to form dense populations, up to 35,000 individuals/m², on a variety of structures including vessels, wharves, mariculture equipment, buoys and other hard substrata (Benson et al., 2001). Because of its dispersed spawning nature, lack of local predators, fast growth, and high tolerance of environmental conditions, this mussel population is expected to expand in Atlantic habitats until it reaches its thermal limits (DeVictor and Knott, undated as stated in ISSG, 2005).
Taxonomic TreeTop of page
- Domain: Eukaryota
- Kingdom: Metazoa
- Phylum: Mollusca
- Class: Bivalvia
- Subclass: Pteriomorphia
- Order: Mytiloida
- Unknown: Mytiloidea
- Family: Mytilidae
- Genus: Perna
- Species: Perna viridis
DescriptionTop of page
Perna viridis is a large mussel, 80-100 mm in length, occasionally reaching 165 mm (NIMPIS, 2002). Carpenter and Niem (1998) list the following diagnostic features for this species. P. viridis has an elongate shell, roughly trigonal-ovate in outline with swollen and pointed anterior and compressed posterior ends. Umbones are terminal and sharply tapering, rather than incurved. Anterior margin is reduced, while ventral margin is long and often concave. Outer surface is nearly smooth apart from concentric growth marks and faint radial lines. Periostracum is rather thick and smooth and the ligamental ridge finely pitted. Shell hinge has one small tooth in the right valve and two in the left. The anterior adductor scar is absent in adults. Posterior retractor scars are large, confluent with the posterior adductor scar. Anterior retractor scar is separate, elongate-ovate in shape, and situated a short way to posterior end of ligament.
P. viridis begins its life as a juvenile with a green and blue-green shell that develops brown patches as an adult. It is also distinguishable from other species of Perna (i.e. P. perna and P. canaliculus) by the kidney shape of the posterior adductor muscle, S-shaped pallial line and concave ventral margin (NIMPIS, 2002). Internally, the exhalant siphon and the inner surfaces of the inhalant aperture are outlined with a stripe darker than the variably patterned dark brown mantle (Morton, 1987). Adults of the brown mussel, P. perna,are usually brown "with irregular areas of light brown and green" and distinguished from P. viridis and P. canaliculus by mantle margins lined with enlarged sensory papillae (Siddall, 1980). Young P. canaliculus have light coloured zigzag markings on the outer shell and can be found only in New Zealand (Siddall, 1980).
The outside of the shell is whitish under a bright periostracum which is dark brownish green anteriorly and olive green to bright green posteriorly. The interior shell is an iridescent pale bluish green, with a vivid green margin of periostracum (Carpenter and Niem, 1998).
DistributionTop of page
The native range of Perna viridis is along the Indian coast and throughout the Indo-Pacific (Siddall, 1980). It is broadly distributed in the Indo-Pacific where it ranges west from the Persian Gulf and east to New Guinea and Japan and New Guinea for north and south ranges, respectively. P. viridis occurs naturally and is widely distributed along the intertidal coasts of India (Jones and Alagarswami, 1973). It is also local to Malaysia (Sivalingam, 1977) and rock stacks on the Mangalore coast of India (Kuriakose and Nair, 1976).
According to Siddall (1980), P. viridis has the potential to increase its geographical distribution by step-wise larval dispersal, or "island hopping." Although the bivalve is not part of the native fauna of northern South America (Siddall, 1980), it was first recorded in Trinidad in the mid-1990s (Agard et al., 1992). The mussel later moved southward to the Gulf of Paria by way of prevailing currents (Agard et al., 1992). In 1993 the mussel population from Trinidad is thought to have been dispersed into Venezuela by currents (Agard et al., 1992) and human activities (Rylander et al., 1996).
The first known occurrence of the green mussel in the United States was in Tampa Bay, Florida, during the summer of 1999 (Benson et al., 2001). Scientists suspect that the method of transportation presumably was as larvae in the sea water ballast tanks of ships.
Distribution TableTop of page
The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.
|Continent/Country/Region||Distribution||Last Reported||Origin||First Reported||Invasive||Reference||Notes|
|Atlantic, Western Central||Present||Introduced||Not invasive||Benson et al., 2001; DFAS, 2005|
|Indian Ocean, Eastern||Present||Native||Not invasive||DFAS, 2005|
|Indian Ocean, Western||Present||Native||Not invasive||DFAS, 2005|
|Pacific, Northwest||Present||Introduced||DFAS, 2005|
|Pacific, Western Central||Present||Native||Not invasive||NACA, 1988|
|China||Present||Present based on regional distribution.|
|-Hong Kong||Present||Introduced||DFAS, 2005|
|-Florida||Present||Introduced||Benson et al., 2001|
|-South Carolina||Present||Introduced||Benson, 2011|
Central America and Caribbean
|Jamaica||Present||Introduced||Benson et al., 2001; DFAS, 2005|
|Trinidad and Tobago||Present||Introduced||Benson et al., 2001; DFAS, 2005|
|Venezuela||Present||Introduced||Benson et al., 2001; DFAS, 2005|
IntroductionsTop of page
|Introduced to||Introduced from||Year||Reason||Introduced by||Established in wild through||References||Notes|
|Natural reproduction||Continuous restocking|
|Cook Islands||1984||Unknown||Uwate et al. (1984)|
|Fiji||Philippines||1975||Aquaculture (pathway cause)||Unknown||Uwate et al. (1984)|
|French Polynesia||New Caledonia||1978||Aquaculture (pathway cause)||Unknown||Yes||AQUACOP, and De (1979)|
|New Caledonia||Philippines||1972||Aquaculture (pathway cause)||Unknown||SPIFDA (1972)|
|Samoa||French Polynesia||1982||Aquaculture (pathway cause)||Unknown||Uwate et al. (1984)|
|Tonga||Philippines||1975||Aquaculture (pathway cause)||Unknown||Uwate et al. (1984)|
|Trinidad and Tobago||1990||Unknown||Yes||USGS (2001)|
Habitat ListTop of page
Biology and EcologyTop of page
P. viridis is distinguished from all others of the genus by having 30 instead of 28 diploid chromosomes (Ahmed, 1974).
Natural Food SourcesTop of page
|Food Source||Life Stage||Contribution to Total Food Intake (%)||Details|
ClimateTop of page
|A - Tropical/Megathermal climate||Preferred||Average temp. of coolest month > 18°C, > 1500mm precipitation annually|
Natural enemiesTop of page
Pathway VectorsTop of page
Impact SummaryTop of page
|Fisheries / aquaculture||Positive|
Economic ImpactTop of page
Economically, Perna viridis can cause problems with water systems of industrial complexes by clogging pipes, increasing corrosion and reducing efficiency. The accumulation of P. viridis can cause problems for power plants using seawater as a coolant. Large numbers can block the flow of water causing not only mechanical damage to the pumps (Neitzel et al., 1984), but also reducing the heat transfer efficiency (Rajagopal et al., 1994). Henager et al. (1985) found that this mussel also clogs condenser tubes. According to Fischer et al. (1984), P. viridis can increase the rate of corrosion of tubes. It is also a problem for vessels by causing fouling leading to increased maintenance costs. Rajagopal et al. (1996) discuss methods for the control of P. viridis in the cooling conduits of a coastal power station.
Environmental ImpactTop of page
Perna viridis is now well established in the Tampa Bay estuary, being first discovered by divers doing maintenance work at the TECO power plant in South Hillsborough County (Tampa Bay Estuary Program, 2000). It is believed that the larvae may have been transported via ballast. Consequently, the threat of invasion to neighbouring coastal ports from inter-coastal transport is now a distinct possibility that will require monitoring.
Mazzola and Sara (2001) propose that bivalve organic matter uptake may play an effective role in reducing the environmental impact of organic waste from fish farming. The organic matter produced by bivalves (faecal material) under these hydrodynamic conditions (low current velocities) can be recycled through the filtration activities of the bivalves themselves, together with most of the organic matter produced by fish-farming activities (uneaten feed and faecal material). Bivalve cultivation around cages may reduce the environmental impact of organic waste from fish-farming activities and increase the profitability of fish culture activities. On the other hand, filter feeding P. viridis populations exert keystone effects on coastal plankton by filtering large volumes of water, thereby severely depleting the phytoplankton (Dame, 1996; Prins et al., 1998).
Impact: BiodiversityTop of page
Ecologically, Perna viridis, is able to outcompete many other fouling organisms, causing changes in community structure and trophic relationships. Displacement of native mussels and competition with oyster fishery are recognized as potential negative impacts on biodiversity (USGS, 2001). In particular, P. viridis has become far more abundant on eastern oyster reefs in Florida than previously noted (Baker et al., 2003). Densities are very high, with P. viridis replacing the biomass formerly produced by oysters. The oyster reef matrix and structure remain, but over 90% of adult oysters are recently dead (shells still articulated by the ligament) (Baker et al., 2003).
Social ImpactTop of page
Perna viridis is an effective bioaccumulator, accumulating pollutants in the environment and causing human health problems by food poisoning.
Uses ListTop of page
Human food and beverage
- Canned meat
- Cured meat
- Fresh meat
- Frozen meat
- Live product for human consumption
ReferencesTop of page
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ContributorsTop of page
Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, UK
Distribution MapsTop of page
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