Taxonomic name: Limnoperna fortunei (Dunker, 1857)
Synonyms: Limnoperna depressa (Brandt & Temcharoen, 1971), Limnoperna lacustris (Morton, 1973), Limnoperna siamensis, Limnoperna supoti (Brandt, 1974), Modiola lacustris, Volsella fortunei Dunker, 1857
Common names: golden mussel (English), mejillón dorado (Spanish), mexilhão-dourado (Portuguese-Brazil)
Organism type: mollusc
Limnoperna fortunei (or golden mussel) is an epifaunal mytilid, native to Chinese and south-eastern Asian rivers and creeks. It became established in Hong Kong in 1965, and in Japan and Taiwan in the 1990's. In 1991 it invaded America through the Plata Basin in South America. Limnoperna fortunei modifies the presence and abundance of native macroinvertebrate fauna. It causes great economic damage to water intakes and cooling systems of facilities.[Español]
The shell is dark brown above the umbonal keel and a yellow brown below. The interior of the shell with the nacreous layer, is purple above and white below the keel. The umbones are nearly terminal and the dorsal ligamental margin is straight or slightly curved. The ventral margin of the shell is a variable feature within specimens. There are no hinge teeth and no byssal notch. Similar species include Mytella charruana (d'Orbigny, 1842) and Dreissena polymorpha (Pallas, 1771), the zebra mussel.
Dreissena polymorpha, Mytella charruana
estuarine habitats, lakes, urban areas, water courses, wetlands
Byssally Mussels (Mytilus) and some scallops (e.g., Pteria) are epifaunal, attaching themselves to a substrate by means of collagenous byssal threads) attached to hard substrata, both natural and man-made (plastics, glass, metal, etc). It is a freshwater species but tolerates salinity to 3 ppt. It inhabits temperate and subtropical climates. Specimens under permanent exposure do not survive more than 120 hours while those moistened daily survive up to 168 hours. Smaller mussels reach 100% mortality before larger ones.
The introduction of the golden mussel produces a rapid change in benthic communities and threatens native biodiversity. Golden mussels settle in high numbers on native bivalves (Hyriidae and Mycetopodidae), causing suffocation and starvation, leading to death. Since its invasion of the Plata Basin, dense colonization of hard substrates has modified the presence and abundance of several species of native macroinvertebrates, homogenized the habitat and altered the diet of fish. One fish species (Leporinus obtusidens Valenciennes, 1846) has changed its diet to predate entirely on the golden mussel but is not a limiting factor for its dispersion. The golden mussel produces macrofouling in the water systems of facilities.
Introduction into South America was unintentional through the ballast waters of ocean-going vessels. No uses are known for this species in its native area. It has potential as a bioacumulator of xenobiotics and for water clarifying.
Native range: includes China and southeastern Asia.
Known introduced range: It has been introduced into Hong Kong, Japan, Taiwan; and America, where it is in all of the major rivers of the Plata Basin (Argentine "pampas", neotropical forest and the ecological sanctuary "Pantanal") and the Guaiba Basin. The golden mussel has advanced approximately 240 km per year along the Plata Basin since its introduction.
Introduction pathways to new locations
Floating vegetation/debris: The golden mussel settles on different hard floating sustrata and is transportated with water currents.
Road vehicles (long distance): Introduced as boats are transported for sport fishing.
Ship ballast water: Introduced between continents in ballast water due to commercial trade.
Ship/boat hull fouling: Introduced to other rivers by overland or aquatic transport on boat hulls and trailers.
Local dispersal methods
Boat: Adults may attach to anchors and boat hulls and be transported.
On animals (local): Potential dispersion mode of golden mussel.
Translocation of machinery/equipment (local): Transport and exchange of industrial machinery and fishing equipment.
Water currents: Can drift during larval stages (length: between 5 days to 5 weeks, depending on external factors).
Dr. Gustavo Darrigran, an expert from Argentina, states that stopping the spread of the golden mussel in the natural environment is impossible but it can be decelerated. Appropiate prevention methods can avoid its entrance into facilities. Several control methods are available to remove or kill mussels from fouled man-made subtrates, but these methods are not useful for control in the wild. Controls include mechanical removal, chemical methods, thermal, UV light, electric current, and antifouling paints.
Preventative measures: Identifying potential marine pests- a deductive approach applied to Australia (Hayes, K.R., et al., 2002) presents an inductive hazard assessment protocol that is simple, does not require large amounts of data, and is capable of grouping hazardous species in to high, medium and low priority. Hazard priority is determined by the invasion potential and impact potential of the species. Invasion potential is expressed as the weighted sum of all vessel movements between Australia and ‘infected’ bioregions around the world. Impact potential is expressed in terms of human health, economic and ecological impacts. These were estimated using a web-based questionnaire sent to world-wide experts on each species investigated.
The results of this analysis suggest the following hazard groups for Limnoperna fortunii:
Relative to human impacts: Medium priority – low to medium impact potential and medium invasion potential.
Relative to ecological and economic impacts: Medium priority – medium to high impact potential and medium invasion potential.
Dioecious species, external fertilization, planktonic larvae for several weeks before settling and attaching to a hard substrate.
Trocophore is the first planktonic stage (hours). Several stages of free-swimming planktonic veliger (D-larvae about 7 days, between 80-146 um; veliconcha between 90-237 um and pediveliger or umbonate, more than 256 um). Then the larvae settle as plantigrade mussels, attach to substrate as juveniles. Maturity is reached at about 5.5mm in length. Golden mussels live about 3.2 years.
Compiled by: IUCN/SSC Invasive Species Specialist Group (ISSG)
Last Modified: Sunday, 3 July 2005