Geukensia demissa

Invasion History

First Non-native North American Tidal Record: 1894
First Non-native West Coast Tidal Record: 1894
First Non-native East/Gulf Coast Tidal Record:

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General Invasion History:

The native range of Geukensia demissa spans from the southern Gulf of St. Lawrence to Palm Beach, Florida (Bousfield 1960; Abbott 1974; Morris 1975; Gosner 1978; Krisberg 2009). The Gulf Ribbed Mussel (Geukensia granossisima), formerly considered a subspecies of G. demissa occurs from northwest Florida to Texas (Sarver et al. 1992). Specimens introduced to the West Coast have been identified as G. demissa by molecular methods (Sarver et al. 1992).

North American Invasion History:

Invasion History on the West Coast:

Geukensia demissa was first collected on the West Coast in South San Francisco Bay in 1894 (Carlton 1979). It was introduced with plantings of Eastern Oysters (Miller 2007). It is now one of the most abundant bivalves in San Francisco Bay, from San Pablo Bay to South Bay, where it lines the edges of salt-marsh creeks, channel banks, and retaining walls, attached to the substrate or plant roots by byssus threads (Carlton 1979; Cohen and Carlton 1995). One specimen was collected in Tomales Bay, California (CA) in 1952, and there are other unverified records, for instance, it was reported from Tomales Bay by Fairey et al. (2002), based on a 2001 survey. This mussel was found in 1986 in Morro Bay, CA but was not reported during subsequent surveys in 2001 (Needles 2007). In Southern California, G. demissa was found in Newport Bay in 1955, Alamitos Bay in 1968 (Reish 1968, cited by Carlton 1979; 2000, Cohen et al. 2002; Burnaford et al. 2011), Anaheim Bay in 1972 (Reish 1972, cited by Carlton 1979), and the adjacent Bolsa Chica Lagoon in 1992 (Carlton 1992). Occurrences in southern California could be associated with Eastern Oyster transfers, but the documented transfers were few and small. Introductions with ballast water or fouling are possible. Further south, it is established and very abundant in Estero de Punta Banda, Baja California Norte, Mexico, where it was introduced by the early 1980s (Torchin et al. 2005).

Invasion History Elsewhere in the World:

Geukensia 'demissa' has been reported and studied in Lake Maracaibo, Venezuela, where it was introduced by 1994, and is now established (Romero et al. 2003; Baez et al. 2005). However, these records could refer to G. granossisima (Gulf Ribbed Mussel), which was formerly considered conspecific with G. demissa.

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Description

Geukensia demissa has a moderately thin, oblong-oval shell. The outer surface is marked by numerous strong radial ribs with widely spaced growth lines. The beak of the shell is subterminal, located somewhat above the hinge of the shell. Hinge teeth are absent. The ventral portion of the shell is slightly curved inward. The exterior color is yellowish-green to bluish brown, while the interior is silvery white, and often iridescent. Adult mussels range from 20 to 1400 mm (Abbott 1974; Brousseau 1984; Coan et al. 2000; Coan and Vantich-Scott 2007). Larvae are described and illustrated by Chanley and Andrews (1971). The larvae are planktotrophic, and settle at 215-305 µm (Chanley and Andrews 1971).

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Taxonomy

Ecology

General:

Geukensia demissa has separate sexes. Animals mature at about one year of age. Sexes differ in the color of the mantle, with females being yellowish brown, while males are a cream color. Eggs are brooded, but sperm are released into the water column. Fertilized eggs develop into a planktonic trochophore larva, then into a shelled veliger. The larvae settle at 220-300 µm (Chanley and Andrews 1971).

Geukensia demissa larvae settle on rocks, wood, roots of marsh plants, and peat, though they are most abundant in marsh habitats (Abbott 1974; Morris 1975; Gosner 1978; Lippson and Lippson 1997). Marsh populations tolerate water temperatures from -1.8 to 37⁰C (Read and Cumming 1967, cited by Hicks and McMahon 2002), and doubtless survive higher air temperatures. They also tolerate wide ranges of salinity, from 5 to 70 PSU (Smithsonian Marine Station at Fort Pierce 2011).

Food:

Phytoplankton; Detritus

Consumers:

Birds, California Clapper Rail

Trophic Status:

Suspension Feeder

SusFed

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Habitats

General Habitat	Unstructured Bottom	None
General Habitat	Oyster Reef	None
General Habitat	Marinas & Docks	None
General Habitat	Salt-brackish marsh	None
General Habitat	Vessel Hull	None
Salinity Range	Mesohaline	5-18 PSU
Salinity Range	Polyhaline	18-30 PSU
Salinity Range	Euhaline	30-40 PSU
Tidal Range	Low Intertidal	None
Tidal Range	Mid Intertidal	None
Vertical Habitat	Epibenthic	None
Vertical Habitat	Endobenthic	None

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Tolerances and Life History Parameters

Minimum Temperature (ºC)	-2	Based on geographical range
Maximum Temperature (ºC)	37	Experimental, ranges of 35-37 reported by Read and Cumming (1967), cited by Hicks and McMahon (2002)
Minimum Salinity (‰)	5	Field record (Miller 2000), Experimental, stepwise decrease (Wells 1961)
Maximum Salinity (‰)	70	Smithsonian Marine Station at Fort Pierce 2011.
Minimum Reproductive Temperature	20	Field data, North Carolina (Borerro 1987)
Maximum Reproductive Temperature	28	Field data, North Carolina (Borerro 1987)
Minimum Duration	12	Lab reared at 22 C (Loosanoff and Davis 1963)
Maximum Duration	43	Lab reared at 22 C (Loosanoff and Davis 1963)
Minimum Length (mm)	20	Minimum Adult Size (Brousseau 1984)
Maximum Length (mm)	140	Maximum Adult Size (Brousseau 1984)
Broad Temperature Range	None	Cold temperate-Subtropical
Broad Salinity Range	None	Mesohaline-Euhaline

General Impacts

Geukensia demissa is very abundant in San Francisco Bay, California. Possible economic impacts include structural effects on marsh channels and dikes. Since these mussels constitute a very large biomass, they could have a significant ecological impact by filtering phytoplankton and competing for food with native bivalves. Some of these impacts also appear probable in Estero Puerto Bando, Mexico, based on field studies by Torchin et al. (2005). However, economic and ecological (experimental) studies of G. demissa have not been conducted in its introduced range.

Ecological Impacts

Habitat Change- High densities of G. demissa in Estero de Punta Banda, Mexico, appear to facilitate growth of the native Pacific cordgrass Spartina foliosa, based on correlation of density of the two organisms (Torchin et al. 2005). The Ribbed Mussels also have a rather unusual impact on a native, endangered, bird. The rapidly closing shells of the mussels can trap chicks and sever toes of adult California Clapper Rails (Rallus longirostris obsoletus) in salt marshes (Carlton 1979; Cohen and Carlton 1995). Geukensia demissa represents a similar threat to another endangered subspecies, R. l. levipes, (Light-Footed Clapper Rail) in Estero Bando (Torchin et al., 2005).

Food/Prey- However, this abundant mussel is also a major food source for the California Clapper Rail (Moffitt 1941, cited by Cohen and Carlton 1995) and doubtless for other wading birds, raccoons, otters, and other salt-marsh predators.

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Regional Impacts

NEP-V	Northern California to Mid Channel Islands		Ecological Impact	Habitat Change
Closing shells can trap chicks and sever toes of adult endangered California Clapper Rails (Rallus longirostris obsoletus) in salt marshes (Carlton 1979; Cohen and Carlton 1995).
P090	San Francisco Bay		Ecological Impact	Habitat Change
Closing shells can trap chicks and sever toes of adult endangered California Clapper Rails (Rallus longirostris obsoletus) in salt marshes (Carlton 1979; Cohen and Carlton 1995).
NEP-VI	Pt. Conception to Southern Baja California		Ecological Impact	Habitat Change
High densities of G. demissa in Estero de Punta Banda, Baja California Norte, Mexico, appear to facilitate growth of the native Pacific cordgrass Spartina foliosa. They also present a hazard to the endangered Light-footed Clapper Rail (Rallus longirostrus levipes), in Estero Puerto Bando, based on the damage seen to the subspecies (R. l. oboletus) in San Francisco Bay (Torchin et al. 2005).
NEP-VI	Pt. Conception to Southern Baja California		Ecological Impact	Competition
Based on the very high biomass seen in Estero de Punta Banda (4 X that of the next most abundant and native species, Tagelus spp.), competition for phytoplankton and other suspended food particles is likely (Torchin et al. 2005).
NEP-V	Northern California to Mid Channel Islands		Ecological Impact	Food/Prey
Geukensia demissa comprised 57% of the diet of the endangered California Clapper Rail (Rallus longirostris obsoletus) (Moffitt 1941, cited by Cohen and Carlton 1995).
P090	San Francisco Bay		Ecological Impact	Food/Prey
Geukensia demissa comprised 57% of the diet of the endangered California Clapper Rail (Rallus longirostris obsoletus) (Moffitt 1941, cited by Cohen and Carlton 1995).
CA	California		Ecological Impact	Food/Prey
Geukensia demissa comprised 57% of the diet of the endangered California Clapper Rail (Rallus longirostris obsoletus) (Moffitt 1941, cited by Cohen and Carlton 1995)., Geukensia demissa comprised 57% of the diet of the endangered California Clapper Rail (Rallus longirostris obsoletus) (Moffitt 1941, cited by Cohen and Carlton 1995).
CA	California		Ecological Impact	Habitat Change
Closing shells can trap chicks and sever toes of adult endangered California Clapper Rails (Rallus longirostris obsoletus) in salt marshes (Carlton 1979; Cohen and Carlton 1995)., Closing shells can trap chicks and sever toes of adult endangered California Clapper Rails (Rallus longirostris obsoletus) in salt marshes (Carlton 1979; Cohen and Carlton 1995).

References

Abbott, R. Tucker (1974) American Seashells, Van Nostrand Reinhold, New York. Pp. <missing location>

Academy of Natural Sciences of Philadelphia 2002-2024a Malacology Collection Search. <missing URL>



Baez, Maria, de Severyn, Yajaira; Severyn, Hector (2005) Reproductive cycle of Geukensia demissa (Bivalvia : Mytilidae) on a beach at Nazaret, El Mojan, Zulia State, Venezuela, Ciencias Marinas 31: 111-118

Bertness, Mark D. (1999) <missing title>, Sinauer Associates, Sunderland MA. Pp. 417

Borrero, Francisco J. (1987) Tidal height and gametogenesis: reproductive variation among populations of Geukensia demissa, Biological Bulletin 173: 160-168

Bousfield, E. L. (1960) Canadian Atlantic Sea Shells, In: (Eds.) . , Ottawa. Pp. <missing location>

Bousfield, E. L. (1969) New records of Gammarus (Crustacea: Amphipoda) from the Middle Atlantic region, Chesapeake Science 10: 1-17

Brousseau, Diane J. (1984) Age and growth rate determinations for the Atlantic ribbed mussel, Geukensia demissa Dillwyn (Bivalvia: Mytilidae), Estuaries 7(3): 233-241

Burnaford, Jennifer L.; Henderson, Scottie Y. Pernet, Bruno (2011) Assemblage shift following population collapse of a non-indigenous bivalve in an urban lagoon, Marine Biology 158: 1915-1927

California Department of Fish and Wildlife (2014) Introduced Aquatic Species in California Bays and Harbors, 2011 Survey, California Department of Fish and Wildlife, Sacramento CA. Pp. 1-36

Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America., Ph.D. dissertation, University of California, Davis. Pp. 1-904

Carlton, James T. (1992) Introduced marine and estuarine mollusks of North America: An end-of-the-20th-century perspective., Journal of Shellfish Research 11(2): 489-505

Castagna, M.; Chanley, P. (1973) Salinity tolerance of some marine bivalves from inshore and estuarine environments in Virginia waters on the western mid-Atlantic coast., Malacologia 12(1): 47-96

Chanley, Paul; Andrews, J. D. (1971) Aids for identification of bivalve larvae of Virginia, Malacologia 11(1): 45-119

Coan, Eugene V.; Valentich-Scott, Paul (2007) The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon, University of California Press, Berkeley CA. Pp. 807-859

Coan, Eugene V.; Valentich-Scott, Paul; Bernard, Frank R. (2000) Bivalve Seashells of Western North Ameira, Santa Barbara Museum of Natural history, Santa Barbara CA. Pp. <missing location>

Cohen, A. N. and 11 authors (2005) Rapid assessment survey for exotic organisms in southern California bays and harbors, and abundance in port and non-port areas., Biological Invasions 7: 995-1002

Cohen, Andrew N. 2005-2024 Exotics Guide- Non-native species of the North American Pacific Coat. https://www.exoticsguide.org/



Cohen, Andrew N. and 10 authors (2005) <missing title>, San Francisco Estuary Institute, Oakland CA. Pp. <missing location>

Cohen, Andrew N. and 12 authors (2002) Project report for the Southern California exotics expedition 2000: a rapid assessment survey of exotic species in sheltered coastal waters., In: (Eds.) . , Sacramento CA. Pp. 1-23

Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

Fairey, Russell; Dunn, Roslyn; Sigala, Marco; Oliver, John (2002) Introduced aquatic species in California's coastal waters: Final Report, California Department of Fish and Game, Sacramento. Pp. <missing location>

Garthwaite, Ronald (1986) The genetics of California populations of Geukensia demissa: further evidence on selective importance of leucine aminopeptidase in salinity acclimation, Biological Journal of the Linnean Society 28: 343-358

Gedan, Keryn B.; Kellogg, Lisa; Breitburg, Denise L. (2014) Accounting for multiple foundation species in oyster reef restoration benefits, Restoration Ecology 22(4): 517-524

Gosner, Kenneth L. (1978) A field guide to the Atlantic seashore., In: (Eds.) . , Boston. Pp. <missing location>

Hicks, D. W.; McMahon, R. F. (2002) Temperature acclimation of upper and lower thermal limits and freeze resistance in the nonindigenous brown mussel, Pern perna (L.), from the Gulf of Mexico., Marine Biology 140: 1167-1179

Kim, Daemin; Taylor, Andrew T.; Near, Thomas J. (2022) Phylogenomics and species delimitation of the economically important Black Basses (Micropterus), Scientific Reports 12(9113): Published online
https://doi.org/10.1038/s41598-022-11743-2

Krisberg, Marlo F. 2009 Let's talk seashells- <i>Geukensia granosissima</i>. <missing URL>



Lee, Harry 2001-2015 Harry Lee's Florida Mollusca Checklists. <missing URL>



Lee. T. ; Ó Foighil, D. (2004) Hidden Floridian biodiversity: mitochondrial and nuclear gene trees reveal four cryptic species within the scorched mussel, Brachidontes exustus, species complex, Molecular Ecology 13: 3527-3542

Loosanoff, V. L. (1955) The European oyster in American waters, Science 121: 119-121

Low-Pfeng, Antonio; Recagno, Edward M. Peters (2012) <missing title>, Geomare, A. C., INESEMARNAT, Mexico. Pp. 236

Miller, A. Whitman; Ruiz, Gregory M.; Minton, Mark S.; Ambrose, Richard F. (2007) Differentiating successful and failed molluscan invaders in estuarine ecosystems., Marine Ecology Progress Series 332: 41-51

Morris, Percy A. (1975) A field guide to shells of the Atlantic, Houghton-Mifflin, Boston. Pp. <missing location>

Needles, Lisa A. (2007) <missing title>, M.S. Thesis, California Polytechnic State University, San Luis Obispo. Pp. <missing location>

Needles, Lisa A.; Wendt, Dean E. (2013) Big changes to a small bay: Introduced species and long-term compositional shifts to the fouling community of Morro Bay (CA), Biological Invasions 15(6): 1231-1251

Reish, Donald J.; Kauwling, Thomas J.; Schreiber, Traynor C. (1975) Annotated checklist of the marine invertebrates of Anaheim Bay, California Department of Fish and Game Fish Bulletin 165: 41-51

Robinson, April; Cohen, Andrew N.; Lindsey, Brie; Grenier, Letitia (2011) Distribution of macroinvertebrates across a tidal gradient, Marin County, California, San Francisco Estuary and Watershed Science 9(3): published online

Romero, J.; Severeyn, H.; García de Severeyn, Y. (2003) Geukensia demissa, new species for the Venezuelan malacological fauna, Revista de Biologia Tropical 51(1): published online

Sarver, S. K.; Landrum, M. C.; Foltz, D. W. (1992) Genetics and taxonomy of ribbed mussels (Geukensia spp., Marine Biology 113: 385-390

Scribano, Giovanni ; Marchini, Agnese; Ros, Macarena (2021) Population dynamics and life history traits of the non-indigenous Paranthura japonica,/em> Richardson (1909) in a recently invaded Mediterranean site, Regional Studies in Marine Science 46(101883): Published

Smithsonian Marine Station at Fort Pierce 2007-2022 Indian River Species Inventory. https://www.irlspecies.org/index.php



Sylvester, Francisco and 8 authors (2011) Hull fouling as an invasion vector: can simple models explain a complex problem?, Journal of Applied Ecology 48: 415-423

Torchin, Mark E.; Hechinger, Ryan F.; Huspeni, Todd C.; Whitney, Kathleen L.; Lafferty, Kevin D. (2005) The introduced ribbed mussel (Geukensia demissa) in Estero de Punta Banda, Mexico: interactions with the native cord grass, Spartina foliosa., Biological Invasions 7: 607-614

U.S. National Museum of Natural History 2002-2021 Invertebrate Zoology Collections Database. http://collections.nmnh.si.edu/search/iz/



Wells, Harry W. (1961) The fauna of oyster beds, with special reference to the salinity factor, Ecological Monographs 31: 239-266

Yale Peabody Museum of Natural History 2008-2016 YPM Invertebrate Zoology - Online Catalog. <missing URL>

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