Crepidula fornicata

Invasion History

First Non-native North American Tidal Record: 1931
First Non-native West Coast Tidal Record: 1931
First Non-native East/Gulf Coast Tidal Record:

---

General Invasion History:

Crepidula fornicata is a sedentary, limpet-like mollusk native to the Northwest Atlantic from Newfoundland to the Gulf of Mexico. It is often extremely abundant in lower intertidal and shallow subtidal waters. There are some museum records from Puerto Rico and the Virgin Islands (Academy of Natural Sciences of Philadelphia 2013), but the Caribbean is not included in the range of C. fornicata given by authors (Bousfield 1960; Abbott 1974; Morris 1975; Rawlings et al. 2011; Rosenberg 2014). It has been introduced to the Northeast Pacific, including Puget Sound and the southern Strait of Georgia (Carl and Guiguet 1972; Carlton 1979; Cohen et al. 1998), and to European waters ranging from Norway to Spain, and the Mediterranean from France to Greece (Blanchard 1997; Sjotun 1997; Zenetos et al. 2003; Zenetos et al. 2005). [Reports of C. fornicata from Japan and Hong Kong (e.g. Blanchard 1997; DAISIE 2009) refer to the Northeast Pacific species C. onyx.] The primary vector of spread has been the transplantation of Eastern Oysters (Crassostrea virginica) from the East Coast of the US to the West Coast and Europe. Within Europe, spread has occurred through various means, including Pacific Oyster (C. gigas) transplants, mussels transplants, movement of fishing and aquaculture gear, hull fouling, or spread as larvae in ballast water or by currents (Blanchard 1997).

North American Invasion History:

Invasion History on the West Coast:

Crepidula fornicata was first reported from the West Coast in Puget Sound, Washington (WA) in 1931 (Sherwood 1931, Galtsoff 1932, cited by Carlton 1979), although it may have been introduced earlier. Carlton (1979) mentions a single specimen in the US National Museum of Natural History collections for Puget Sound in 1905. Some early collections, such as those in Tomales and Humboldt Bays in California (Bonnet 1935; Bonnet 1936, cited by Carlton 1979), and possibly some museum specimens collected in San Francisco Bay in 1973 (California Academy of Sciences 2013), probably represent dead shells introduced with plantings of Eastern Oysters (Crassostrea virginica). Other records include Willapa Bay, WA (in 1937 Hanna 1966; Carlton 1979; Cohen et al. 2001); Grays Harbor, WA (in 1976 Carlton 1979); Puget Sound, WA (Carlton 1979; Cohen et al. 1998; Cohen et al. 2001); Boundary Bay, British Columbia (BC) (Sherwood 1931, cited by Carlton 1979); and Victoria, BC (in 1939, Carlton 1979). Crepidula fornicata is reportedly abundant in southern areas of Puget Sound (Boersma et al. 2006), but absent from northern portions (Dethier and Schoch 2005).

Invasion History Elsewhere in the World:

In European waters, Crepidula fornicata was first reported in Liverpool Bay, England in 1872, but did not persist there. In the late 19th century, it appeared in many English estuaries where Eastern Oysters were planted, including the Thames and many small estuaries in Essex, Suffolk and Lincolnshire (1887-1893, Blanchard 1997; Eno et al. 1997). The oysters did not become established, but C. fornicata developed often dense populations, as in the Blackwater Estuary, Essex (Chipperfield 1951). The spread eastward was rapid, probably due to multiple vectors, including oyster transplants, hull fouling, ballast water, and larval dispersal. The slipper limpet was found in Belgium in 1911, the Netherlands in 1922, and the island of Sylt, Germany and the west coast of Denmark by 1934 (Blanchard 1997; Wolff 2005; Gollasch and Nehring 2006; Kerckhof et al. 2007). By 1948-1950, C. fornicata spread into the mouth of the Baltic, including the west (Skaggerrak) coast of Sweden (Blanchard 1997) and the east (Kattegat) coast of Denmark (Blanchard 1997; Jensen and Knudsen 2005).

It was first reported from Atlantic France in Hermanville, Normandy and Brest, Brittany in 1949 (Goulletquer et al. 2002; Blanchard 1997). Slipper limpets are now very abundant in aquaculture and fishing grounds for Pacific Oysters (Crassostrea gigas) and King Scallops (Pecten maximus). They occur further south in Arcachon Bay, France where it first appeared in 1969, but never attained the high abundances seen elsewhere (de Montaudouin et al. 2001; Goulletquer et al. 2002), and the Rias of Galicia, in northwest Spain, where it is abundant on floating rafts used for oyster and mussel culture (record from 1977, Blanchard 1997). In the Wadden Sea region, in the southeastern North Sea, populations were less dense than in Brittany and Normandy in the mid- 20th century, but have been increasing in the last decade, apparently due to climate change (Thieltges et al. 2003; Thieltges et al. 2004).

In the English Channel, C. fornicata has spread from east to west. It was found in the Solent, near the Isle of Wight in West Sussex in 1913 (Blanchard 1997), but by 1944 it had spread to Falmouth at the mouth of the Channel (Blanchard 1997). In 1958-59, it occurred in only 14% of 50 near-shore English Channel stations surveyed, but in 2006, it was found at 44% of stations, with an increase in abundance, and occurring at some stations down to 60 m depth. Expansion of its range was considered to be a possible response to a warming climate (Hinz et al. 2011). In 1960, it was found in County Kerry, on the west coast of Ireland (Arnold 1960), but did not persist there. However, it was found in Belfast Lough, Northern Ireland, off the Irish Sea, in 2007 and is now established (Minchin 2007; McNeill et al. 2010). On the Norwegian coast, C. fornicata was first found in the Oslofijord in 1968 and occurs west to Mandal, and sparingly on the west coast from Orresanden, near Stavanger, in shallow bays where oysters occur (Sjotun 1997).

In the Mediterranean, C. fornicata was first reported from a French lagoon (La Seyne sur Mer) in 1957 (Clanzig 1989) and was subsequently found in other lagoons used for oyster culture (Zibrowius 1991; Zenetos et al. 2003). It is established in lagoons and bays in mainland Italy, Sicily, Malta, and Greece (Zenetos et al. 2003; Zenetos et al. 2005).

---

Description

Crepidula fornicata is a limpet-like marine snail, with an oval, convex shell. The shell can range from fairly flat to deeply arched in cross-section, depending on growth conditions. The apex, is turned to one side, not separate from the body of the shell. The shell has an interior shelf-like deck, covering about 1/2 of the aperture, giving it a boat-like appearance. The deck is slightly concave, and its edge is sinuous and asymmetrical. The color of the shell is highly variable, dirty-white to tan, with brown blotches and sometimes with radiating brown lines. The interior of the shell is brown and glossy, while the deck is white. Shells can be up to 50 mm long. Description from: Abbott 1974, Morris 1975, Gosner 1978, Lippson and Lippson 1997.

It grows in curved stacks of four or five individuals, but sometimes as many as 12 snails can be stacked on top of one another. Slippersnails are protandrous hermaphrodites. The oldest individuals, at the bottom of the stack, are female, while the youngest, at the top, are males, and the middle individuals are usually in the process of changing sex. The snails are sedentary and are usually attached to hard surfaces, such as rocks, dead or live shells, or debris such as bottles and cans (Chipperfield 1951; Gosner 1978; Lippson and Lippson 1997).

The planktonic veliger of C. fornicata is described and illustrated by Fretter and Pilkington (1970).

---

Taxonomy

Ecology

General:

Crepidula fornicata is a common Atlantic filter-feeding marine gastropod, with a limpet-like body. It lives attached to solid substrates, but this can often be a live or empty shell of C. fornicata, another mollusk, or other hard-shelled animal (Gosner 1978). Crepidula fornicata is a protandric hermaphrodite. It first matures as a male, which can occur at as young as only 2 months after settling and 4 mm in size. This slipper shell often forms stacks of 2 to 20 individuals, with the oldest and largest female on the bottom, young males on the top, and individuals changing sex, in between. Males are somewhat mobile and copulate with females nearby, or below them on the stack, while females grow to fit the surface, to which they are attached, and are sedentary (Henry et al. 2010). Among populations, and stacks of individuals on Long Island's (New York) south coast bays, the size of the largest male varies from 10 to 40 mm (Hoch and Cahill 2012). As males grow, they undergo a sex-change, but usually do not mature as females before their 3rd year. The size and timing of the transition depends on whether the male is solitary or attached to a female (Coe 1938; Henry et al. 2010). The mean size of transitional individuals was 22-32 mm among five Long Island populations. Among stacks in these five populations, the largest female ranged from 20 to 50 mm (Hoch and Cahill 2012). Eggs are laid in capsules on the forward edge of the foot, each containing 180-260 eggs. Twelve animals in France laid 52-69 capsules and 9648-17940 eggs in a single spawning (Deslous-Paoli and Heral 1986). Specimens in Norway had 10,000 to 55,000 eggs per spawning, with egg production increasing with shell length (Pechenik et al. 2017). Eggs take about 17 days to hatch at 18.5°C and hatch into swimming planktotrophic veligers. The veligers settle after 11.5-14 days at 18-20°C, as juveniles 0.94 - 1.00 mm long (Collin 2003). At low food levels and temperature around 15°C development can be prolonged to 32 days (Pechenik and Lima 1984).

Crepidula fornicata can grow on a variety of substrates, including rock, wood, docks, floats, ship hulls, and shells of dead or live mollusks (including other C. fornicata) (Verrill and Smith 1873; Visscher 1927). It is most common at salinities of 20-30 PSU and inhabits shallow estuaries with a wide temperature range (Verrill and Smith 1873; Wass 1972; Leathem and Maurer 1975). In the northern part of its range in Germany, it appears to have been limited by mortality due to cold winter water temperatures and did not develop the high biomasses seen further south (Thieltges et al. 2004). In Bourgneuf Bay, central Atlantic France, increasing water temperatures and increasing chlorophyll concentrations were correlated with earlier breeding and a higher frequency of brooding females (Valdizan et al. 2011). Common molluscan hosts include Crassostrea virginica (Eastern Oyster – East Coast), C. gigas (Pacific Oyster – West Coast and Europe), and Mytilus edulis (Blue Mussel – East Coast and Europe) (de Montaudouin et al. 1999; Thieltges et al. 2006).

Crepidula fornicata is a filter feeder, trapping phytoplankton and detritus in strings of mucus on its gills, which are conveyed to its mouth (Lippson and Lippson 1997). Stable isotope measurements indicate that C. fornicata is an unselective feeder and because of its occurrence near the bottom, often on soft sediments, it ingests more detritus and benthic algae than more selective feeders, such as the Pacific Oyster (Decottignies et al. 2007a; Decottignies et al. 2007b; Lefebvre et al. 2009). In Europe, major predators include Asterias rubens (Common Starfish) and Carcinus maenas (Green Crab) (Thieltges et al. 2004).

Food:

Phytoplankton

Consumers:

Crabs; Starfish

Competitors:

Oysters; Mussels

Trophic Status:

Suspension Feeder

SusFed

---

Habitats

General Habitat	Oyster Reef	None
General Habitat	Marinas & Docks	None
General Habitat	Unstructured Bottom	None
General Habitat	Rocky	None
General Habitat	Vessel Hull	None
Salinity Range	Polyhaline	18-30 PSU
Salinity Range	Euhaline	30-40 PSU
Tidal Range	Subtidal	None
Tidal Range	Low Intertidal	None
Vertical Habitat	Epibenthic	None
Vertical Habitat	Littoral	None

---

---

Tolerances and Life History Parameters

Minimum Temperature (ºC)	0	Based on geographic range
Minimum Salinity (‰)	15	Experimental, lowest tested,j uveniles reared at 30 ppt, and transferred, (Pechenik and Eyster 1989)
Minimum Reproductive Temperature	10	Beginning of spawning (egg deposition) in Blackwater River, Essex (Chipperfied 1951). Minimum temperature for larval development is around 15 C (Pechenik and Lima 1984).
Maximum Reproductive Temperature	29	Maximum temperature tested for larval rearing (Pechenik and Lima 1984)
Maximum Reproductive Salinity	30	Highest tested, controls, Pechenik and Eyster 1989)
Minimum Duration	11.5	Experimental, at 20 C, high food (Pechenik et al. 1996, cited by Collin 2003b)
Maximum Duration	32	Experimental, at 15 C, low food (Pechenik and Lima 1984)
Minimum Length (mm)	4	Males, can mature at as small as 4 mm, 2 months after settling. They can reach maturity as females at 20-25 mm (Coe 1938; Henry et al. 2010).
Maximum Length (mm)	50	Abbott 1974
Broad Temperature Range	None	Cold temperate-Warm temperate
Broad Salinity Range	None	Polyhaline-Euhaline

General Impacts

Crepidula fornicata is a fouling organism with potentially important impacts on human structures and shellfish and is an abundant filter-feeder and structural component of estuarine communities in invaded regions. Most information on ecological impacts of this species come from the coasts of northern Europe, from Germany to the northern Bay of Biscay. This species is included on a list of 'the 100 most invasive alien species in Europe' (DAISIE 2009). There is little specific information on its ecological or economic impacts on the West Coast of North America.

Economic Impacts

Fisheries: In European waters, Crepidula fornicata affects the survival, growth, and harvesting of commercially important shellfish. They also alter estuarine habitats in ways that may affect fish and other mobile fisheries species. Crepidula fornicata, as a filter-feeder, is widely believed to affect the growth of other bivalves by competition in a variety of ways, as well as altering habitats (see 'Ecological Impacts'). They affect fisheries more directly by fouling structures used in aquaculture and by fouling oysters, mussels, and scallops, requiring much time and effort to remove the limpets and clean the catch (Blanchard 1997; Thieltges et al. 2003; Frésard and Boncoeur 2006; Clark 2008).

Shipping: Crepidula fornicata does occur on ships’ hulls and buoys (Visscher 1927; WHOI 1952), but has not been reported as a major ship-fouling organism.

Industry: Crepidula fornicata has been reported to be an important fouling organism in power plants in the northeastern US (Holm et al. 2006), but not in European or other non-native waters.

Ecological Impacts

Herbivory: Crepidula fornicata is a filter-feeding gastropod, which traps and ingests suspended particles, mostly phytoplankton, but also detritus. In European waters, it has developed dense populations and large biomasses in bays and estuaries, with the potential to reduce phytoplankton concentrations (Blanchard 1997; Decottignies et al. 2007a; Decottignies et al. 2007b). However, not much information is available on individual and population feeding rates. In the Bay of Brest, Brittany, the invasion of C. fornicata was associated with a decrease in the spring diatom bloom and a shift of summer phytoplankton from diatoms to flagellates (Chavaud et al. 2000).

Competition: Crepidula fornicata, as an abundant, sedentary filter-feeder, has the capacity to compete with native suspension feeders by competition for food, space, or by settling directly on the shells of other organisms and interfering with their movement, feeding, or other behavior. Feeding competition has been studied most carefully with the Pacific Oyster (Crassostrea gigas), because of the latter's economic importance. Stable isotope analysis indicates that during much of the year in Brittany, food sources of the two species are distinct, because the oyster is a more selective feeder, while C. fornicata ingests much more detritus and benthic microalgae. However, in winter and early spring, when phytoplankton abundance is low, competition is possible (de Montaudouin et al. 1999; Thieltges et al. 2006; Decottignies et al. 2007a; Decottignies et al. 2007b). Crepidula fornicata competes for space on the bottom, with the native Great Scallop (Pecten maximus) and is believed to adversely affect scallop populations and fisheries in English and French waters (Frésard and Boncoeur 2006; Clark 2008). The growth and survival of Blue Mussels (Mytilus edulis) in the Wadden Sea were found to be reduced by C. fornicata, but not through competition for food. Instead attached limpets increased the hydrodynamic stress on the mussels, making it more likely for them to be detached, and shifting energy resources to increased production of byssus threads (Thieltges 2005; Thiletges and Buschbaum 2007).

Habitat Change: Crepidula fornicata has been a very successful invader in European waters, covering large areas of substrate with stacks of live animals and dead shells. The live animals produce vast quantities of feces and pseudofeces, and the shells themselves reduce bottom currents, also contributing to siltation. On one hand, the shells contribute to structure, including attachment sites for sessile organisms and hiding places for epifauna, but the siltation creates anoxic sediment, discouraging burrowing organisms (de Montaudouin and Sauriau 1999; Vallet et al. 2001; Blanchard 2009). Among faunal changes following C. fornicata's invasion are a population explosion of brittlestars (Blanchet-Aurigny et al. 2012) and a decline in recruitment of an important food fish, Solea solea (Common Sole) (Le Pape et al. 2004).

Parasite Community Effects: In experiments in the Wadden Sea, Germany, Crepidula fornicata together with the Pacific Oyster (Crassostrea gigas) and other filter feeders, such as the Softshell Clam (Mya arenaria), were found to affect transmission of the trematode parasite Himasthla elongata, by filtering out the metacercariae, without becoming infected themselves. The effect of these invaders was to reduce the parasite load on native bivalves, through dilution (Thieltges et al. 2008; Thieltges et al. 2009).

---

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>



Arnold, D. C. (1960) Occurrence of the Slipper Limpet, Crepidula fornicata L., in Ireland, Nature 186: 95

Bañón, Rafael; Rolán, Emilio; García-Tasende, Manuel (2008) First record of the purple dye murex Bolinus brandaris (Gastropoda: Muricidae) and a revised list of non native molluscs from Galician waters (Spain, NE Atlantic)., Aquatic Invasions 3(3): 331-334

Bazterrica, María Cielo; Hidalgo, Fernando J. ; Rumbold, Carlos Casariego, Agustina Mendez; Jaubet , María Lourdes; Merlo, Matías; Cesar, Ines , Pro (2022) Macrofaunal assemblages structure three decades after the first report of the invasive Crassostrea gigas reefs in a soft-intertidal of Argentina, Estuarine, Coastal and Shelf Science 270(107832): Published online
https://doi.org/10.1016/j.ecss.2022.107832

Beukema, J. J.; Dekker, R. (2011) Increasing species richness of the macrozoobenthic fauna on tidal flats of the Wadden Sea by local range expansion and invasion of exotic species, Helgoland Marine Research 65: 155-164

Bishop, John D. D.; Wood, Christine A.; Lévêque, Laurent; Yunnie, Anna L. E.; Viard, Frédérique (2015b) Repeated rapid assessment surveys reveal contrasting trends in occupancy of marinas by non-indigenous species on opposite sides of the western English Channel, Marine Pollution Bulletin 95: 699-706

Blanchard, M. (1997) Spread of the Slipper Limpet, Crepidula fornicata (L. 1758 in Europe. Current state and consequences, Scientia Marina 61(2): 109-118

Blanchard, Michel (2009) Recent expansion of the slipper limpet population (Crepidula fornicata) in the Bay of Mont-Saint-Michel (Western Channel, France), Aquatic Living Resources 22: 11-19

Blanchard, Michel; Pechenik, Jan A.; Giudicelli, Emilie; Connan, Jean-Paul ; Robert, René (2008) Competition for food in the larvae of two marine molluscs, Crepidula fornicata and Crassostrea gigas, Aquatic Living Resources 21: 197-205

Blanchet-Aurigny, A. and 5 authors (2012) Multi-decadal changes in two co-occurring ophiuroid populations, Marine Ecology Progress Series 460: 79-90

Boersma, P. D; Reichard, S. H.; Van Burne, A. N. (2006) <missing title>, Invasive species in the Pacific Northwest, Seattle WA. Pp. 1-285

Bohn, Katrin; Richardson, Christopher A.; Jenkins, Stuart R. (2013) The importance of larval supply, larval habitat selection and post-settlement mortality in determining intertidal adult abundance of the invasive gastropod Crepidula fornicata, Journal of Experimental Marine Biology and Ecology 440: 132-140

Bohn, Katrin; Richardson, Christopher A.; Jenkins, Stuart R. (2013) Larval microhabitat associations of the non-native gastropod Crepidula fornicata and effects on recruitment success in the intertidal zone, Journal of Experimental Marine Biology and Ecology 448: 289-297

Bohn, Katrin; Richardson, Christopher A.; Jenkins, Stuart R. (2015) The distribution of the invasive non-native gastropod Crepidula fornicata in the Milford Haven Waterway, its northernmost population along the west coast of Britain, Helgoland Marine Research 69: 313-325

Bohn, Katrin; Richardson, Christopher; Jenkins, Stuart (2012) The invasive gastropod Crepidula fornicata: reproduction and recruitment in the intertidal at its northernmost range in Wales, UK, and implications for its secondary spread, Marine Biology published online: <missing location>

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

Boyd, Milton J.; Mulligan, Tim J; Shaughnessy, Frank J. (2002) <missing title>, California Department of Fish and Game, Sacramento. Pp. 1-118

Breton, Gerard; Girard, Annie; Lagardere, Jean-Paul (1995) Especes animales benthiques des bassins du port du Havre (Normandie, France) rares, peu connues ou nouvelles pour la region., Bulletin Trimestrial de la Societe geologique de Normandie 82(2): 7-28

Buschbaum, Christian; Lackschewitz, Dagmar; Reise, Karsten (2012) Nonnative macrobenthos in the Wadden Sea ecosystem, Journal of Ocean Management 68: 89-101

California Academy of Sciences 2005-2015 Invertebrate Zoology Collection Database. <missing URL>



Carl, G. Clifford; Guiguet, C. J. (1972) Alien animals in British Columbia., British Columbia Provincial Museum: Department of Recreation and Conservation: Handbook 14: 1-102

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

Chauvaud, Laurent; Jean, Frederic; Ragueneau, Olivier; Thouzeau, Gerard (2000) Long-term variation of the Bay of Brest ecosystem: Benthic-pelagic coupling revisited, Marine Ecology Progress Series 200: 35-48

Chipperfield, P. N. J. (1951) The breeding of Crepidula fornicata (L.) in the River Blackwater, Essex., Journal of the Marine Biological Association of the United Kingdom 30(1): 49-71

Clanzig, Sylvain (1989) Invertebres d'introduction recente dans les lagunes mediterraneennes du languedoc-roussillon, Bulletin de la Societe Zoologique de France 114(3): 151-152

Clark, Sarah (2008) <missing title>, Devon Sea Fisheries Committee, Plymouth, UK. Pp. 1-32

Coe, W. R. (1938) Influence of association on the sexual phases of gastropods having protandric onsecutive sexuality, Biological Bulletin 75(2): 274-285

Cohen, Andrew N. and 22 authors (2001) <missing title>, Washington State Department of Natural Resources, Olympia. Pp. <missing location>

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>

Cohen, Andrew; and 16 authors. (1998) <missing title>, Washington State Department of Natural Resources, Olympia, Washington. Pp. 1-37

Collin, Rachel (2001) The effects of mode of development on phylogeography and population structure of North America Crepidula (Gastropoda: Calyptraeidae), Molecular Ecology 10: 2249-2262

Collin, Rachel (2003a) The utility of morphological characters in gastropod phylogenetics: an example from the Calyptraeidae., Biological Journal of the Linnean Society 78: 541-593

Collin, Rachel (2003b) Worldwide patterns in mode of development in calyptraeid gastropods, Marine Ecology Progress Series 247: 103-122

Crocetta, Fabio (2012) Marine alien Mollusca in Italy: a critical review and state of the knowledge, Journal of the Marine Biological Association of the United Kingdom 92(6): 1357-1365

Cruz-Ábrego, Flor Marina; Hernández-Alcántara, Pablo; Solís-Weis, Vivianne (1994) [Study of polychaetes (Annelida) and mollusks (Gastropoda and Bivalvia) in the seagrass beds (Thalassia testudinum) and mangroves (Rhizopliora mangle) in Terminos Lagoon, Campeche, Mexico], Anales Del Instituto de Ciencias Del Mar y Limnologia 21(1-2): 1-13

DAISIE (Delivering Alien Invasive Species Inventories to Europe) (2009) Handbook of alien species in Europe, Springer, Dordrecht, Netherlands. Pp. 269-374

de Montaudouin, X., Sauriau, P.G. (1999) The proliferating Gastropoda Crepidula fornicata may stimulate macrozoobenthic diversity, Journal of the Marine Biological Association of the United Kingdom 79: 1067-1077

de Montaudouin, X.; Labarraque, D.; Giraud, K.; Bachelet, G. (2001) Why does the introduced gastropod Crepidula fornicata fail to invade Arcachon Bay (France)?, Journal of the Marine Biological Association of the United Kingdom <missing volume>: 97-104

de Montaudouin, Xavier; Audemard, Corinne; Labourg, Pierre-Jean (1999) Does the slipper limpet (Crepidula fornicata, L.) impair oyster growth and zoobenthos biodiversity? A revisited hypothesis, Journal of Experimental Marine Biology and Ecology 235: 105-124

de Montaudouin, Xavier; Sauriau, Pierre-Guy (2000) Contributions to a synopsis of marine species richness in the Pertuis-Charentais Sea with new insights into the soft-bottom macrofauna of the Marennes-Oleron Bay, Cahiers de Biologie Marine 41: 181-222

Decottignies, Priscilla; Beninger, Peter G.; Rincé, Yves; Robins, Richard J.; Riera, Pascal (2007a) Exploitation of natural food sources by two sympatric, invasive suspension-feeders: Crassostrea gigas and Crepidula fornicata., Marine Ecology Progress Series 334: 179-192,

Decottignies, Priscilla; Beninger, Peter G.; Rincé, Yves; Riera, Pascal (2007b) Trophic interactions between two introduced suspension-feeders, Crepidula fornicata and Crassostrea gigas , are influenced by seasonal effects and qualitative selection capacity, Journal of Experimental Marine Biology and Ecology 342: 231-241

Deslous-Paoli, J.-M.; Héral, M. (1986) [Crepidula fornicata L. (Gastropoda, Calyptraeidae) in the Marennes-Oléron basin: Compostion and energetic value of individuals and spawnings], Oceanologica Acta 9(3): 305-311

Deslous-Paoli, Jean-Marc (1985) Crepidula fornicata L. (gasteropode) dans le bassin de Marennes-Oleron: structure, dynamique et production d'une population., Oceanologica Acta 8(4): 453-460

Dethier, Megan N.; Carl Schoch, G. (2005) The consequences of scale: assessing the distribution of benthic populations in a complex estuarine fjord, Estuarine, Coastal and Shelf Science 62: 253-270

Diederich, Casey M. and 5 authors (2011) Low salinity stress experienced by larvae does not affect post-metamorphic growth or survival in three calyptraeid gastropods, Journal of Experimental Marine Biology and Ecology 397: 94-105

Doberteen, Ross A.; Pechenik, Jan A. (1987) Comparison of larval bioenergetics of two marine gastropods with widely differing lengths of larval life, Thais haemastoma caniculata (Gray) and Crepidula fornicata (L.), Journal of Experimental Marine Biology and Ecology 109: 173-191

Dupont, L.; Jollivet, F. Viard (2003) High genetic diversity and ephemeral drift effects in a successful introduced mollusc (Crepidula fornicata: Gastropoda), Marine Ecology Progress Series 253: 183-195

Eldredge, L. G. (1994) Introductions of Commercially Sginificant Aquatic Organsisms to th Pacific Islands, South Pacific Commission, Noumea, New Caledonia. Pp. <missing location>

Eno, N. Clare (1996) Non-native marine species in British waters: effects and controls, Aquatic Conservation: Marine and Freshwater Ecosystems 6: 215-228

Eno, N. Clare; Clark, Robin A.; Sanderson, William G. (1997) <missing title>, Joint Nature Conservation Committee, Peterborough. Pp. <missing location>

Eno, N.C., Clark, R.A., Sanderson, W.G. 1997-2012 Directory of Non-Native Marine Species in British waters. <missing URL>



Foss, Stephen (2009) <missing title>, California Department of Fish and Game, Sacramento CA. Pp. <missing location>

Frésard, Marjolaine; Boncoeur, Jean (2006) Costs and benefits of stock enhancement and biological invasion control: the case of the Bay of Brest scallop fishery, Aquatic Living Resources 19: 299-305

Fretter, Vera; Pilkington, Margaret (1970) Prosobranchia: Veliger larvae of Taenioglossa and Stenoglossa, ICES Zooplankton Identification Sheets 129-132: 1-26

Galtsoff, Paul S. (1964) The American oyster, Crassostrea virginica Gmelin. Chapter 18: Environmental factors affecting oyster populations, Fisheries Bulletin 64: 397-456

Gargan, Laura M.; Brooks , Paul R; ; Vye, Siobhan R.; . Joseph E. Ironside . Jenkins, Stuart R.; Crowe, Tasman P.;. Carlsson,Jens (2021) The use of environmental DNA metabarcoding and quantitative PCR for molecular detection of marine invasive non-native species associated with artificialstructures, Biological Invasions Published online: <missing location>

Gittenberger, Adriaan; Rensing, Marjolein; Stegenga, Herre; Hoeksema, Bert (2010) Native and non-native species of hard substrata in the Dutch Wadden Sea, Nederlandse Faunistiche Mededelingen 33: 20-76

Goldstien, S. J .; Schiel, D. R.; Gemmell, N. J . (2010) Regional connectivity and coastal expansion: differentiating pre-border and post-border vectors for the invasive tunicate Styela clava, Molecular Ecology 19: 874-885

Gollasch, Stephan; Haydar, Deniz; Minchin, Dan; Wolff,Wim J.; Reise, Karsten (2009) Biological Invasions in Marine Ecosystems., Springer-Verlag, Berlin Heidelberg. Pp. 507-528

Gollasch, Stephan; Nehring, Stefan (2006) National checklist for aquatic alien species in Germany., Aquatic Invasions 1(2): 245-269

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

Goulletquer, Philippe; Bachelet, Guy; Sauriau, Pierre; Noel, Pierre (2002) Invasive aquatic species of Europe: Distribution, impacts, and management, Kluwer Academic Publishers, Dordrecht. Pp. 276-290

Hedgpeth, J. W. (1980) The problem of introduced species in management and mitigation, Helgoländer Meeresuntersuchungen 33: 662-673

Henry, Jonathan J.; Collin, Rachel; Perry, Kimberly J. (2010) The slipper snail, Crepidula: an emerging lophotrochozoan model system, Biological Bulletin 218: 211-229

Hinz, H.; Capasso, E.; Lilley, M.; Frost, M.; Jenkins, S. R. (2011) Temporal differences across a bio-geographical boundary reveal slow response of sub-littoral benthos to climate change, Marine Ecology Progress Series 423: 69-82

Hoch, J. Matthew; Cahill, Abigail E. (2012) Variation in size at sex-change among natural populations of the protandrous hermaphrodite, Crepidula fornicata (Gastropoda, Calyptraeidae), Marine Biology 159: 897-905

Holm, Eric R. and 12 authors (2006) Interspecific variation in patterns of adhesion of marine fouling to silicone surfaces, Biofouling 22(3-4): 233-243

Jensen, Kathe R. and 10 authors (2023) Reviewing Iintroduction histories, pathways, invasiveness, and impact of Non-Indigenous Species in Danish Marine Waters, Diversity 15(434): Published online
https://doi.org/10.3390/d15030434

Jensen, Kathe R.; Knudsen, Jorgen (2005) A summary of alien marine benthic invertebrates in Danish waters., Oceanological and Hydrobiological Studies 34 (suppl. 1): 137-161

Kerckhof, Francis; Haelters, Jan; Gollasch, Stephan G. (2007) Alien species in the marine and brackish ecosystem: the situation in Belgian waters., Aquatic Invasions 2(3): 243-257

Kostecki, C. and 5 authors (2011) Reduction of flatfish habitat as a consequence of the proliferation of an invasive mollusc, Estuarine, Coastal and Shelf Science 92: 154-160

Krueger-Hadfield, Stacy A.; Oetterer, Alexis P. ; Lees, Lauren E.; Hoffman, Jessica M.; Sotka, Erik E.; Murren, Courtney J. (2023) Phenology and thallus size in a non-native population of Gracilaria vermiculophylla, Journal of Phycology 59: 926–938
DOI: 10.1111/jpy.13371

Lavigne, Andrea S. Sunesen, Ines Sar, Eugenia A. (2015) Morphological, taxonomic and nomenclatural analysis of species of Odontella, Trieres and Zygoceros (Triceratiaceae, Bacillariophyta) from Anegada Bay (Province of Buenos Aires, Argentina), Diatom Research 30: 307-331

Le Cam, Sabrina; Viard, Frederique (2011) Infestation of the invasive mollusc Crepidula fornicata by the native shell borer Cliona celata: a case of high parasite load without detrimental effects, Biological Invasions 13: 1087-1098

Le Pape, O.; Guerault, D; Desaunay, Y. (2004) Effect of an invasive mollusc, American slipper limpet Crepidula fornicata, on habitat suitability for juvenile common sole Solea solea in the Bay of Biscay., Marine Ecology Progress Series 177: 107-115

Leathem, Wayne, Maurer, Don (1975) The distribution and ecology of common marine and estuarine gastropods in the Delaware Bay area, Nautilus 89(3): 73-79

Lefebvre, Sebastien and 7 authors (2009) Seasonal dynamics of trophic relationships among co-occurring suspension feeders in two shellfish culture dominated ecosystems, Estuarine, Coastal and Shelf Science 82: 415-425

LeJart, Morgane; Hily, Christian (2011) Differental response of macrobenthos to formation of novel oyster reefs (Crassostrea gigas Thunberg) on soft and rocky substrate in theinteridal of the Bay of Brest, France, Journal of Sea Research 65: 84-93

Lippson, Alice Jane; Lippson, Robert L. (1997) <missing title>, Johns Hopkins University Press, Baltimore. Pp. <missing location>

Liu, Wenliang; Liang, Xiaoli ; Zhu, Xiaojing (2015) A new record and mitochondrial identification of Synidotea laticauda Benedict, 1897 (Crustacea: Isopoda: Valvifera: Idoteidae) from the Yangtze Estuary, China, Zootaxa 4294: 371-380

Martin,Sophie; Thouzeau, Gerard; Chauvaud, Laurent ; Frederic, Jean; Guerin,Laurent; Clavier, Jacques (2006) Respiration, calcification, and excretion of the invasive slipper limpet, Crepidula fornicata L.: Implications for carbon, carbonate, and nitrogen fluxes in affected areas., Limnology and Oceanography 51(5): 1996-2007

McGee, B. L.; Targett, N. M. (1989) Larval habitat selection in Crepidula (L.) and its effect on adult distribution patterns, Journal of Experimental Marine Biology and Ecology 131: 195-214

McGlashan, Dugald J.; Ponniah, Mark; Cassey, Phillip; Viard, Frederique (2008) Clarifying marine invasions with molecular markers: an illustration based on mtDNA from mistaken calyptraeid gastropod identifications., Biological Invasions 10: 51-57

McNeill, Gavin; Nunn, Julia; Minchin, Dan (2010) The slipper limpet Crepidula fornicata Linnaeus, 1758 becomes established in Ireland, Aquatic Invasions 5(Supplement 1): S21-S25

Minchin, Dan (2007) A checklist of alien and cryptogenic aquatic species in Ireland., Aquatic Invasions 2(4): 341-366

Minchin, Dan; Eno, Claire (2002) Invasive aquatic species of Europe: distribution, impacts and management., Kluwer Academic Publishers, Dordrecht/ Boston/ London. Pp. <missing location>

Mineur, Frederic and 5 authors (2012) Changing Coasts: Marine aliens and artificial structures, Oceanography and Marine Biology, an Annual Review 50: 189-234

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

Moulin, Frederic Y. and 5 authors (2007) Impact of an invasive species, Crepidula fornicata, on the hydrodynamics and transport ptoperties of the benthic boundary layer., Aquatic Living Resources 20: 15-31

Nikolaev, I. N. (1951) [On new additions to the fauna and flora of the North sea and Baltic from distant regions], Zoologicheskii Zhurnal 30(8): 556-561

Otero, M.; Cebrian, E.; Francour, P.; Galil, B.; Savini, D. (2013) <missing title>, International Union for Conservation of Nature, Malaga, Spain. Pp. 136

Pechenik, Jan A.; Lima, Gail M. (1984) Relationship between growth, differentiation, and length of larval life for individually reared larvae of the marine gastropod, Crepidula fornicata., Biological Bulletin 166: 537-549

Pechenik, Jan A.; Eyster, Linda S. (1989) Influence of delayed metamorphosis on the growth and metabolism of young Crepidula fornicata (Gastropoda) juveniles, Biological Bulletin 176: 14-24

Pechenik, Jan A.; Fried, Bernard; Simpkins, Heather L. (2001) Crepidula fornicata is not a first intermediate host for trematodes: who is?, Journal of Experimental Marine Biology and Ecology 261: 211-264

Pederson, Judith and 6 authors (2011) Climate change and non-native species in the North Atlantic, ICES Cooperative Reseach Report 310: 174-190

Pongparadon, Supattra; Zuccarello, Giuseppe C.; Prathep, Anchana (2017) High morpho-anatomical variability in Halimeda macroloba (Bryopsidales, Chlorophyta) in Thai waters, Phycological Research 65: 136-145
doi: 10.1111/pre.12172

Quinn, Emma A.; Malkin, Sophie H.; Thomas, Jessica E.' Poole, Ryan; Davies, Charlotte E.; Rowley, Andrew F.; Coates, Christopher J. (2022) Invasive slipper limpets (Crepidula fornicata) act like a sink, rather than source, of Vibrio spp., Biological Invasions <missing volume>: Published online
https://doi.org/10.1007/s10530-022-02868-6

Rawlings, Timothy A.; Hayes, Kenneth A.; Cowie, Robert H. Collins, Timothy M. (2007) The identity, distribution, and impacts of non-native apple snails in the continental United States., BMC Evolutionary Biology 7(97): 1-4

Rawlings, Timothy A.; Aker, Jana M.; Brunel, Pierre (2011) Clarifying the northern distributional limits of the slipper limpet Crepidula fornicata in the Northwestern Atlantic, American Malacological Bulletin 29(1/2): 105-119

Reise, Karsten; Olenin, Sergej; Thieltges, David W. (2006) Are aliens threatening European aquatic coastal ecosystems?, Helgoland Journal of Marine Research 60: 77-83

Richard, Joelle; Huet, Martial; Thouzeau, Gerard; Paulet, Yves-Marie (2006) Reproduction of the invasive slipper limpet, Crepidula fornicata, in the Bay of Brest, France., Marine Biology 149: 789-801

Rigal, Francois; Viard, Frederique; Ayata, Sakina-Dorothee; Comtet, Thierry (2010) Does larval supply explain the low proliferation of the invasive gastropod Crepidula fornicata in a tidal estuary?, Biological Invasions 12: 3171-3186

Riggs, Sharon R. (2011) <missing title>, Padilla Bay NERR, Padilla Bay WA. Pp. 5

Riquet, F.; Le Cam, S.; Fonteneau, E.; Viard, F. (2016) Moderate genetic drift is driven by extreme recruitment events in the invasive mollusk Crepidula fornicata, Heredity 117: 42-50

Riquet, Florentine; Daguin-Thiebaut, Claire; Ballenghien, Marion; Bierne, Nicolas; Viard, Frederique (2013) Contrasting patterns of genome-wide polymorphism in the native and invasive range of the marine mollusc Crepidula fornicata, Molecular Ecology 22: 1003-1018

Rosenberg, Gary 1995-2023 Malacolog 4.1. http://www.malacolog.org/



Silverbrand, Samantha J.; Lindsay, Sara M.; Rawson, Paul D. (2020) Detection of a novel species complex of shell-boring polychaetes in the northeastern United States, Invertebrate Biology 140: e12343
DOI: 10.1111/ivb.12343

Sjotun, Kjersti (1997) A new observation of Crepidula fornicata (Prosobranchia, Calyptraeidae) in western Norway, Sarsia 82: 275-276

Stiger-Pouvreau, Valérie; Thouzeau, Gérard (2015) Marine species introduced on the French Channel-Atlantic coasts: a review of main biological invasions and impacts, Open Journal of Ecology, 5: 227-257

Thieltges, D. W.; Bordalo, M. D.; Caballero Hernandez, A.; Prinz, K.; Jensen, K. T. (2008) Ambient fauna impairs parasite transmission in a marine parasite-host system, Parasitology 135: 1111-1116

Thieltges, D. W.; Strasser, M.; Reise, K. (2003) The American slipper limpet Crepidula fornicata L. in the northern Wadden Sea 70 years after its introduction, Helgoland Journal of Marine Research 57: 27-33

Thieltges, David W. (2005) Impact of an invader: epizootic American slipper limpet Crepidula fornicata reduces survival and growth in European mussels, Marine Ecology Progress Series 286: 13-19

Thieltges, David W.; Buschbaum, Christian (2007) Mechanism of an epibiont burden: Crepidula fornicata increases byssus thread production by Mytilus edulis, Journal of Molluscan Studies 73: 75-77

Thieltges, David W.; Reise, Karsten; Prinz, Katrin; Jensen, Thomas (2009) Invaders interfere with native parasite-host interactions, Biological Invasions 11: 1421-1429

Thieltges, David W.; Strasser, Matthias; Reise, Karsten (2006) How bad are invaders in coastal waters? The case of the American slipper limpet Crepidula fornicata in western Europe., Biological Invasions 8: 1673-1680

Thieltges, David W.; Strasser, Matthias; Van Beusekom, Justus E. E.; Reise, Karsten (2004) Too cold to prosper--winter mortality prevents population increase of the introduced American slipper limpet Crepidula fornicata in nothern Europe., Journal of Experimental Marine Biology and Ecology 311: 375-391

Thomsen, Mads S. and 6 authors (2008) Annual changes in abundance of non-indigenous marine benthos on a very large spatial scale., Aquatic Invasions 3(2): 133-140

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



Valdizan, Alexandra; Beninger, Peter G.; Decottignies, Priscilla; Chantrel, Marianne; Cognie, Bruno (2011) Evidence that rising coastal seawater temperatures increase reproductive output of the invasive gastropod Crepidula fornicata, Marine Ecology Progress Series 438: 153-165

Vallet, Carole; Dauvin, Jean-Claude; Hamon, Dominique; Dupuy, Christine (2001) Effect of the introduced common slipper shell on the suprabenthic biodiversity of the subtidal communities in the bay of Saint-Brieuc, Conservation Biology 15(6): 1686-1690

Verrill, A.E.; Smith, S.I. (1873) <missing title>, 1 Report of the United States Commission of Fish and Fisheries, <missing place>. Pp. 1-757

Viard, Frederique; Ellien, Celine; Dupont, Lise (2006) Dispersal ability and invasion success of Crepidula fornicata in a single gulf: insights from genetic markers and larval-dispersal model., Helgoland Journal of Marine Research 60: 144-152

Virgili. Riccardo; Tandua, Valentina; Katsanevakis, Stelos; Terlizzi, Francesco; Villani, Guido; Fontano. Angelo; Crocetta, Fabio (2022) The Miseno Lake (Central-Western. Mediterranean Sea): An overlooked reservoir of non-indigenous and cryptogenic ascidians in a marine reserve, Frontiers in Marine Science 9(866906): Published online

Visscher, J. Paul (1927) Nature and extent of fouling of ship's bottoms., Bulletin of the Bureau of Fisheries 43: 193-252

Wahl, Martin (2008) Ecological lever and interface ecology: Epibiosis modulates the interactions between host and environments, Biofouling 24(6): 427-438

Wallentinus, Inger; Nyberg, Cecilia D. (2007) Introduced marine organisms as habitat modifiers., Marine Pollution Bulletin 55: 323-332

Wass, Melvin L. (1972) A checklist of the biota of lower Chesapeake Bay, Special Scientific Report, Virginia Institute of Marine Science 65: 1-290

Wolff, W. J. (2005) Non-indigenous marine and estuarine species in the Netherlands., Zoologische Verhandelingen 79(1): 1-116

Wonham, Marjorie J.; Lewis, Mark A. (2009) Biological Invasions in Marine Ecosystems, Springer, Berlin Heidelberg. Pp. 71-105

Woodruff, David S., McMeekin, Lori L., Mulvey, Margaret, Carpenter, Patricia M. (1986) Population genetics of Crepidula onyx: variation in a California slipper snail recently established in China, The Veliger 29(1): 53-63

Woods Hole Oceanographic Institution, United States Navy Dept. Bureau of Ships (1952) Marine fouling and its prevention., United States Naval Institute., Washington, D.C.. Pp. 165-206

Zaiko, Anastasija; Lehtiniemi, Maiju; Narscius, Aleksas; Olenin, Sergej (2011) Assessment of bioinvasion impacts on a regional scale: a comparative approach, Biological Invasions 13: 1739-1765

Zenetos, A. and 8 authors (2005) Annotated list of marine alien species in the Mediterranean with records of the worst invasive species., Mediterranean Marine Science 6(1): 63-118

Zenetos, A.; Koutsoubas, D.; Vardala-Theodorou, E. (2005) Origin and vectors of introduction of exotic mollusks in Greek waters., Belgian Journal of Zoology 135(2): 279-286

Zibrowius, Helmut (1991) Ongoing modification of the Mediterranean marine fauna and flora by the establishment of exotic species., Mesogee 51: 83-107

---