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Species
Geukensia demissa (Dillwyn, 1817)
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NCBI
EOL Text
Gulf of St. Lawrence (unspecified region), northern Gaspe waters, southern Gaspe waters (Baie des Chaleurs, Gaspe Bay to American, Orphan and Bradelle banks; eastern boundary: eastern Bradelle Valley); Prince Edward Island (from the northern tip of Miscou Island, N.B. to Cape Breton Island south of Cheticamp, including the Northumberland Strait and Georges Bay to the Canso Strait causeway); Cobscook Bay
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Geukensia demissa can be found among intertidal oyster reef clusters in numbers over 1,500 per m2 (Coen et al. 1999). Unlike oysters, ribbed mussels have the ability to reattach if dislodged, providing this species with more opportunities to respond to disturbance. Densities of 2000 up to 10,000 per m2 have been reported for this species in areas along the northern Atlantic coast.
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Source | http://www.sms.si.edu/irlspec/Geukensia_demissa.htm |
The ribbed mussel is native to the Atlantic coast of North America, from the southern Gulf of St. Lawrence, Canada to northeastern Florida and along the Gulf of Mexico from Florida to Yucatan.
In the mid 1800s the ribbed mussel was introduced to San Francisco Bay, California, apparently by accident, included with live oysters shipped by trans-continental rail for cultivation in the Bay. Since then it has been found in other locations on the Pacific coast, from Alamitos Bay south to Anaheim Bay, Newport Bay, Bolsa Chica Lagoon and Estero de Punta Banda, Baja California Norte, Mexico. The locations may have been sites of unrecorded oyster transplants, or the mussels may have arrived after attaching to hulls or other mobile objects.
Biogeographic Regions: atlantic ocean (Native ); pacific ocean (Introduced )
- Brousseau, D. 1984. Age and growth rate determinations for the Atlantic ribbed mussel, Geukensia demissa Dillwyn (Bivalvia: Mytilidae). Estuaries, 7/3: 233-241.
- Abbott, R. 1974. American Seashells. New York: Van Nostrand Reinhold.
- Blackwell, J., L. Gainey, Jr., J. Greenberg. 1977. Shell ultrastructure in two subspecies of the ribbed mussel, Geukensia demissa (Dillwyn, 1817). Biological Bulletin, 152: 1-11.
- Cohen, A., J. Carlton. 1995. Nonindigenous Aquatic Species in a United States Estuary: A Case Study of the Biological Invasions of the San Francisco Bay and Delta. Washington, D.C.: U.S. Fish and Wildlife Service.
- Carlton, J. 1979. History, Biogeography, and Ecology of the Introduced Marine and Estuarine Invertebrates of the Pacific coast of North America. Davis, CA: Ph.D. Thesis, University of California.
- Carlton, J. 1992. Introduced mairne and estuarine mollusks of North America: an end-of-the-20th-century perspective. Journal of Shellfish Research, 11: 489-505.
- Chesapeake Bay Program, 2004. "Bay Field Guide" (On-line). Atlantic Ribbed Mussel. Accessed March 11, 2007 at http://www.chesapeakebay.net/ribbedmussel.htm.
- Cohen, A. 2005. "Geukensia demissa" (On-line). Guide to the Exotic Species of San Francisco Bay. Accessed March 11, 2007 at www.exoticsguide.org.
- Torchin, M., R. Hechinger, T. Huspeni, K. Whitney, K. Lafferty. 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.
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Communication Channels: tactile ; chemical
Perception Channels: visual ; tactile ; chemical
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United States
Origin: Unknown/Undetermined
Regularity: Regularly occurring
Currently: Present
Confidence: Confident
Type of Residency: Year-round
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This species has a planktonic larval stage that allows for dispersal to distant locations. The larvae settle out of the water column and attach to oyster reefs, saltmarsh plants, and other solid objects in shallow or intertidal waters. They then transform into the sedentary shelled form. Subsequent growth rate and time to maturity is strongly determined by environmental conditions, including tidal exposure, temperature, and available food. Time to ma
Development - Life Cycle: metamorphosis
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The ribbed mussel can be found along the Atlantic coast from the Gulf of Maine to Florida and the Gulf of Mexico (Franz 2001). It also reported from the San Francisco Bay on the West coast where it was introduced. Geukensia demissa occurs in the Indian River Lagoon.
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Source | http://www.sms.si.edu/irlspec/Geukensia_demissa.htm |
The age of ribbed mussels can be determined by back counting the annual growth ribs on the shell.
Mortality of plankton larvae is unknown. Mortality rates of juveniles in the year following settlement have been recorded to average about 55 % partially due to winter icing on the marsh.
Even though mussels are less abundant higher on shore, survivorship increases with increasing tidal height. Some reach 15 years or older. Mussels on the marsh edge tend to be around 6 or 7 years old.
Average lifespan
Status: wild: 15 years.
- Brousseau, D. 1982. Gametogenesis and spawning in a population of Geukensia demissa (Pelecypoda:Mytilidae) from Westport, Connecticut. Veliger, 24: 247-251.
- Franz, D. 2001. Recruitment, survivorship, and age structure of a New York Ribbed Mussel population (Geukensia demissa) in relation to shore level - a nine year study. Estuaries, 24: 319-327.
- Lutz, R., M. Castagna. 1980. Age composition and growth rate of a mussel (Geukensia demissa) population in a Virginia salt marsh. Journal Molluscan Studies, 46: 106-115.
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Source | http://animaldiversity.ummz.umich.edu/accounts/Geukensia_demissa/ |
Ribbed mussel are relatively large mussels. They range from 5 - 10 cm (4 inches) in length. The largest specimen recorded reached 13 cm. The shell is moderately thin and oblong or fan shaped. The upper margin is straight or slightly convex. The dorsal and ventral margins are parallel.
The periostracum (thin, glossy outer shell layer) is glossy, brownish black with some yellow to a bleached white color. It is grooved with pronounced, unbranched, radiating ribs, largest on the upper part of the hind end above a broad umbonal ridge, fine along lower margin. These give the species its common name. The inside of the shell is pearlescent, sometimes white or bluish-gray, tinged with purple/blue or purple/red at hind margin. There are no teeth at the hinge. At the head end of the shell there is no shelf on the inside.
In the summer, the color of the mantle varies between the sexes. In females the mantle tends to be a medium chocolate brown, in males is is lighter, a yellowish cream white color.
The broad umbo (hump at the center of the concentric growth lines) is a short distance behind the narrowed, rounded front end. The periostracum is often worn away around the umbo. There is no external siphon.
Like most bivalves, the species has a muscular "foot", capable of moving he animal slowly through sediment, . The foot can also secrete byssal threads -- hair-like adhesive filaments that help the mussel attach to grasses, nearby shells, or other solid objects.
One subspecies of Geukensia demissa is recognized. G. d. granosissima (Sowerby, 1914) ranges from the east and west coast of Florida to the Gulf of Mexico (Yucatan). It differs in the morphology of the shell (rib number) and ultrastructure.
Range length: 13 (high) cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes colored or patterned differently
- eNature.com, 2005. "Ribbed Mussel" (On-line). Accessed March 11, 2007 at http://www.enature.com.
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Source | http://animaldiversity.ummz.umich.edu/accounts/Geukensia_demissa/ |
Ribbed mussels are broadcast spawners. At a particular time of year, individuals release eggs and sperm into the water, and fertilization occurs there.
Mating System: polygynandrous (promiscuous)
Sexual maturation in this species is primarily determined by body weight, and this in turn is strongly influenced by the environment of individual mussels. Along the edge of the marsh, mussels usually become sexually mature during their second growing season. The minimum size for gametogenesis is around 12 mm. The average size for the sexually mature ribbed mussel is greater than 20 mm. A few meters from the edge of the marsh, the minimum size increases to about 17 mm. Higher up on shore, it is not uncommon to see mussels greater than 35 mm that do not show any external characteristics of gametogenesis. Mussels that are farther from the marsh edge tend to grow slower as a result of shorter submergence and feeding time, which can delay maturation an additional year compared to the mussels along the edge of the marsh.
The ribbed mussel spawns by external fertilization, sperm and eggs are released into the water column.
Gametogenesis begins in early spring and peaks in June and July. Maximum reproduction occurs between June and August, depending on location, and larvae can be found into early fall.
Breeding interval: It is unknown how many times they spawn during one summer, but it is thought to be only one time.
Breeding season: in the summer months
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); broadcast (group) spawning
There is practically no parental investment in this species -- eggs do not receive substantial provisioning, and there is no interaction with offspring after gametes are released.
Parental Investment: no parental involvement
- Franz, D. 1997. Resource alloacation in the intertidal salt-marsh mussel Geukensia demissa in relation to shore level. Estuaries, 20: 134-148.
- Borrero, F., T. Hilbish. 1988. Temporal variation in shell and soft tissue growth of the mussel Geukensia demissa. Marine Ecology Progress Series, 42: 9-15.
- Borrero, F. 1987. Tidal height and gametogenesis: reproduction variation among population of Geukensia demissa. Biological Bulletin, 173: 160-168.
- Chesapeake Bay Program, 2004. "Bay Field Guide" (On-line). Atlantic Ribbed Mussel. Accessed March 11, 2007 at http://www.chesapeakebay.net/ribbedmussel.htm.
- Cohen, A. 2005. "Geukensia demissa" (On-line). Guide to the Exotic Species of San Francisco Bay. Accessed March 11, 2007 at www.exoticsguide.org.
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Rights holder/Author | ©1995-2013, The Regents of the University of Michigan and its licensors |
Source | http://animaldiversity.ummz.umich.edu/accounts/Geukensia_demissa/ |