View source for Biology:Arcuatula senhousia

{{short description|Species of mollusc}}
: ''For the Asian green mussel, see [[Biology:Perna viridis|Perna viridis]].''
{{Speciesbox
| image = Musculista senhousia (Asian mussel).JPG
| image_caption = Exterior of left [[Biology:Valve (mollusc)|valve]] of an Asian date mussel
| status =
| status_system =
| taxon = Arcuatula senhousia
| authority =  (Benson), 1842) 
| synonyms =
* ''Modiola aquarius'' <small>Grabau & King, 1928</small>
* ''Modiola bellardiana'' <small>Tapparone Canefri, 1874</small>
* ''Modiola senhousia'' <small>Benson, 1842</small>
* ''Musculista senhousia'' (<small>Benson, 1842)</small>
| synonyms_ref = <ref name = WoRMS>{{cite web | url =http://www.marinespecies.org/aphia.php?p=taxdetails&id=505946  | title = ''Arcuatula senhousia'' (Benson, 1842)  | accessdate = 2 March 2017 | publisher = [[Organization:World Register of Marine Species|World Register of Marine Species]] | author1 = Markus Huber | author2 = Bruce Marshall | year = 2016}}</ref> 
}}

'''''Arcuatula senhousia''''', commonly known as the '''Asian date mussel''', '''Asian mussel''' or '''bag mussel''', is a small saltwater [[Biology:Mussel|mussel]], a marine bivalve mollusk species in the family [[Biology:Mytilidae|Mytilidae]], the mussels. Other [[Biology:Common name|common name]]s for this species include: the Japanese mussel, Senhouse's mussel, the green mussel (a name also applied to ''[[Biology:Perna viridis|Perna viridis]]''), and the green bagmussel. It is harvested for human consumption in China.

This mussel is native to the Pacific Ocean from Siberia to Singapore, but it has also been accidentally introduced and become an [[Earth:Invasive species|invasive species]] in numerous other areas worldwide. It can live in the [[Earth:Intertidal zone|intertidal]] or shallow [[Earth:Neritic zone|subtidal zone]]s. In California the species has been recorded in densities of up to 150,000 individuals per square meter. It grows quickly and lives only about 2 years. It prefers soft substrates and surrounds its shell in a dense mass of byssus.

One of several negative impacts of this invasive species is that it has a detrimental effect on [[Biology:Zostera|eelgrass]].

==Description==
This species is differentiated from other mussels by its relatively small size and inflated shape, as well as by the greenish colour of its outer periostracal layer. The shell has radiating reddish lines on its posterior surfaces, small internal teeth on the dorsal edge posterior to the [[Biology:Ligament|ligament]], and small ribs anterior to the umbones. It can grow up to {{ convert | 30 | mm | in | frac=8 }} in length.<ref name=edgar>Edgar, Graham J. ''Australian Marine Life: The Plants and Animals of Temperate Waters.'' Victoria: Reed, 1997.</ref><ref name=slack>Slack-Smith, S.M., A. Brearley. "Musculista senhousia (Benson, 1842); a mussel recently introduced into the Swan River estuary, Western Australia." ''Records of the Western Australian Museum.'' 13.2 (1987): 225-230.</ref> It is also known for its relatively fast growth and has a maximum lifetime of about two years.<ref name=crooks1>Crooks, Jeffrey A. "Predators of the invasive mussel Musculista senhousia (Mollusca: Mytilidae)." ''Pacific Science.'' 56.1 (2002): 49-57.</ref>

==Distribution==
[[Image:Musculista senhousia (Asian mussel) inside.JPG|thumb|left|230px|Interior of left valve of Asian date mussel]]
''Arcuatula senhousia'' is native to the [[Earth:Pacific Ocean|Pacific Ocean]], inhabiting coastal areas from Siberia and the Kuril Islands south to [[Place:Singapore|Singapore]].<ref name="Willan"/> The mussel has become an invasive species in {{wipe|California}}, the Mediterranean, Australia, and New Zealand.<ref name=slack/> It was introduced to the Western coast of the United States sometime in the early 20th century with shipments of Japanese oysters. In 1983, large specimens of the species were collected in the Swan River [[Earth:Estuary|estuary]] in Western Australia. The mussel has been present in the Waitematā Harbour of [[Place:Auckland|Auckland]] since the 1970s, becoming established by 1984.<ref name="Willan">{{Cite journal| issn = 00670464| volume = 22| pages = 85–96| last = Willan| first = R. C.| title = SUCCESSFUL ESTABLISHMENT OF THE ASIAN MUSSEL Musculista senhousia (BENSON IN CANTOR, 1842) IN NEW ZEALAND| journal = Records of the Auckland Institute and Museum| date = 1985}}</ref> Specimens have also been reported at Tamar estuary in Tasmania.<ref name=slack/> Invasion of the aforementioned locales is thought to have been achieved in a variety of manners: the mussels were transported on the hulls of ships, in water-intake chambers and the ducts of ships, as [[Earth:Plankton|plankton]]ic [[Biology:Larva|larva]]e carried in the [[Engineering:Ballast tank|ballast]] water of bulk-cargo vessels, in association with intentionally introduced oysters, and by [[Biology:Lessepsian migration|Lessepsian migration]] through the Suez Canal.<ref name=slack/><ref name=crooks1/> 
{{clear}}

==Ecology==
===Habitat===
The Asian date mussel is generally found in sheltered mud or other soft substrates up to twenty metres below the surface of the water.<ref name=edgar/> In China and Japan, where it is native, the mussels are found in intertidal zones with densities up to 2500 individuals per square metre. In Australia, as an [[Earth:Invasive species|invasive species]], they are found from {{ convert | 0.5 | to | 4 | m | ft | abbr=off | frac=2 }} below the surface of the water in slightly higher densities.<ref name=slack/>

Along the Western coast of North America, however, the species generally reaches densities of 5000 to 10,000 individuals per square metre and has been recorded at densities of up to 150,000 individuals per square metre in Mission Bay in San Diego, California, USA. The mussel is most abundant in the summer and early autumn.<ref name=crooks1/> In the Swan River [[Earth:Estuary|estuary]] in Western Australia, the mussel population has a high mortality rate in the late autumn and early winter. This may be the result of a decrease in water salinity from increased rainfall.<ref name=slack/>

===Behavior===
''Arcuatula senhousia'' uses byssal threads to form a sort of cocoon around itself. The cocoon may be necessary for protection due to the relatively thin shells of the species, as well as to assist in the stabilization of the individuals within the sediment. The cocoons of the individuals can intertwine to form a mat that tends to trap other shells, sediment, [[Biology:Algae|algae]], and [[Earth:Detritus|detritus]] on its surface.<ref name=crooks1/>

===Predators===
Predators of the Asian date mussel vary depending on the native fauna of the area. In the Swan River [[Earth:Estuary|estuary]] of Western Australia, for example, [[Earth:Predation|predation]] occurs mainly by boring [[Biology:Carnivore|carnivorous]] gastropods such as ''Nassarius burchardi'' or ''[[Biology:Bedeva paivae|Bedeva paivae]]'', which drill through the mussel's thin shell.<ref name=slack/> In Mission Bay in San Diego, however, the mussel's main predators include the [[Biology:Yellowfin croaker|yellowfin croaker]], [[Biology:Spotfin croaker|spotfin croaker]], [[Biology:Sargo|sargo]], [[Biology:Willet|willet]], and the [[Biology:Marbled godwit|marbled godwit]] (three fish and two bird species respectively). Other less significant predators include [[Biology:Carnivore|carnivorous]] gastropods (especially ''[[Biology:Pteropurpura festiva|Pteropurpura festiva]]''), crustaceans, echinoderms, [[Biology:Fish|fish]], and diving ducks.<ref name=crooks1/> Recent research{{citation needed|date=October 2020}} has emphasized the importance of the [[Earth:Predation|predation]] of ''Arcuatula senhousia'' by native fauna as a means of reducing the negative effects of the [[Earth:Invasive species|invasive species]] on ecosystems.

Asian date mussels also face [[Earth:Predation|predation]] by humans. The mussel is gathered as food in China, as food for domestic organisms{{clarify|reason="Domestic animals"?|date=October 2020}} in Japan, Thailand, and India, as well as bait for fishing throughout Asia. There are currently no commercial or recreational uses for the mussel in the invaded areas. It has been suggested that harvesting the species might help reduce the effects of their invasion; however, there are a number of detrimental effects associated with benthic harvesting.<ref name=crooks1/>

==Impact on invaded ecosystems==
Research has shown that the Asian date mussel can have a variety of effects on various ecosystems. In the Swan River [[Earth:Estuary|estuary]] in Western Australia, for example, the presence of mats of ''Arcuatula senhousia'' has caused an increase in the [[Biology:Biomass|biomass]] of benthic macro-organisms in general.<ref name=slack/>

In Mission Bay in San Diego, California, USA, the increasing abundance of Asian date mussels has caused a decrease in species richness and abundance of the native ''Solen rostriformis'' as well as the complete disappearance of the native ''Chione fluctifraga''. The Asian date mussel has also become one hundred times more abundant than any native bivalves. Two other native species have appeared in the bay, however: ''[[Biology:Macoma nasuta|Macoma nasuta]]'' and ''Chione undatella''. Laboratory experiments using these species show that the growth and survival of the surface-dwelling and suspension-feeding species of the Chione genus decrease dramatically in areas where the Asian date mussel is abundant. Populations of the deeper-dwelling and deposit-feeding ''Macoma nasuta'' are not significantly affected, however, by the invasion of the mussel.<ref>Crooks, Jeffrey A. "Assessing invader roles within changing ecosystems: Historical and experimental perspectives on an exotic mussel in an urbanized lagoon." Biological Invasions. 3.1 (2001): 23-36.</ref>

Similar occurrences have been observed at Sacca di Goro, a brackish [[Earth:Lagoon|lagoon]] in the Po River Delta of the Northern [[Place:Adriatic Sea|Adriatic Sea]] in Italy, which the Asian date mussel invaded in the early 1990s. Researchers there have found that growth and survival of [[Biology:Filter feeder|suspension feeders]] has significantly decreased following the arrival of the Asian date mussel. There has also been a concomitant increase in the abundance of detritivores and herbivores.<ref>Mistri, M., R. Rossi, and E.A. Fano. "The spread of an alien bivalve (''Musculista senhousia'') in the Sacca di Goro Lagoon (Adriatic Sea, Italy)." Journal of Molluscan Studies. 70.3 (2004): 257-261.</ref>

Laboratory research has also shown that deeper-dwelling species are less affected by the invasion of the Asian date mussel. Mussel mats have no significant effect on the mortality of deeper-dwelling [[Biology:Clam|clam]] species such as ''Tapes decussatus'' and ''Ruditapes philippinarum''.<ref>Mistri, Michele. "Effect of Musculista senhousia mats on clam mortality and growth: much ado about nothing?" Aquaculture. 241.1-4 (2004): 207-218.</ref>

Competition with native species is the primary cause of concern in areas of New Zealand where the Asian date mussel has invaded. There are significantly fewer macrofaunal invertebrates and there has been an eightfold decrease in the abundance of infaunal bivalves. Scientists suggest, however, that the adverse environmental effects of the mussel in New Zealand will be localized and short-lived.<ref>Creese, Robert, Simon Hooker, Sharon De Luca, and Yvette Wharton. "Ecology and environmental impact of Musculista senhousia (Mollusca: Bivalvia: Mytilidae) in Tamaki Estuary, Auckland, New Zealand." New Zealand Journal of Marine and Freshwater Research. 31.2 (1997): 225-236.</ref>

''Arcuatula senhousia'' shares its habitat with eelgrass (''[[Biology:Zostera marina|Zostera marina]]'') in many of the areas in which it has invaded. The presence of the mussel has been shown to affect [[Biology:Rhizome|rhizome]] growth in the eelgrass. This decreases the ability of established patches to spread. The Asian date mussel had the most detrimental effect on rhizome growth in areas where the eelgrass was sparse and patchy. This is a cause of concern for conservationists because beds of eelgrass are already degraded and sparse as a result of anthropogenic forces. The presence of ''Arcuatula senhousia'' can only worsen the situation.<ref>Reusch, Thorsten B.H. and Susan L. Williams. "Variable responses of native eelgrass ''Zostera marina'' to a non-indigenous bivalve ''Musculista senhousia''." Oecologia. 113.3 (1998): 428-441.</ref>

==References==
{{Reflist}}

==External links==
* [https://web.archive.org/web/20070221081828/http://www.marine.csiro.au/crimp/Reports/Infosht7_Musc0700S3.pdf CSIRO fact sheet]

{{Taxonbar|from=Q13392661}}

[[Category:Mytilidae]]

{{Sourceattribution|Arcuatula senhousia}}