Sphaerium corneum
Linnaeus, 1758
Common Name:
European fingernail clam
Synonyms and Other Names:
Identification:
This fingernail clam has an oval, thin shelled, lustrous brown to gray, and somewhat inflated shell with a height to length ratio of 0.80–0.88. Juveniles’ shells are more yellow. The dorsal shell margin is curved and there are low central beaks with straight edges on either side. The shell is covered in evenly spaced striae that become finer and fade out toward the beaks. The narrow 4th and 2nd cardinal teeth are very close to parallel and the former overlaps the latter. The narrow and curved 3rd cardinal is parallel to the hinge plate and expanded and often bifurcate posteriorly (Clarke 1981, Herrington 1962, Mackie et al. 1980, Mackie 2000, Peckarsky et al. 1993).
Sphaerium corneum can grow to approximately 9–13.5 mm in length (Clarke 1981, Herrington 1962, Letarte and Vaillancourt 1986, Mackie 2000).
Size:
up to 14 mm
Native Range:
Sphaerium corneum is native to Eurasia (Clarke 1981, Herrington 1962).
Great Lakes Nonindigenous Occurrences:
Sphaerium corneum was first recorded in the Great Lakes basin in Lake Ontario in 1924. It has also been recorded from Lake Erie, Lake Michigan, Lake Superior, Rice Lake (which is part of the Trent-Severn Canal system connecting Lake Huron and Lake Ontario), and Lake Huron, although it is uncommon in the latter. It could have been present in the Great Lakes as early as the 1900s (Grigorovich et al. 2003, Herrington 1962, Mackie et al. 1980, Mackie 2000, Mills et al. 1993). Also found in Lake Champlain, and Hudson River in New York.
Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Sphaerium corneum are found here.
Full list of USGS occurrences
Table last updated 4/19/2024
† Populations may not be currently present.
Ecology:
Found in freshwater lakes and slow-moving rivers; prefers eutrophic, shallow waters, vegetation; lives in the sediment. Sphaerium corneum occurs in lotic and lentic water bodies. It often prefers somewhat eutrophied, more lentic habitats, but it cannot tolerate extremely high organic pollution. Nor does it tolerate desiccation well. Sphaerium corneum has a high capacity for anaerobiosis and is able to survive anoxic conditions for around 400 days at 0ºC and for 9 days at 20ºC. Sphaerium corneum prefers hard waters with high magnesium, calcium, and bicarbonate concentrations. It is found on fine sand, mud, silt, organic matter, and sometimes on gravel. In Lake Michigan it is found down to 10 m.
In some German ponds, densities of 51,000–76,500 clams per m2 can occur. In Lake Superior, densities can reach 61 clams per m2 and in the St. Lawrence River they can reach 500–8000 clams per m2 (Boycott 1936, Clarke 1981, Dussart 1979, Grigorovich et al. 2003, Herrington 1962, Hinz 1977, Holopainen 1987, Krieger 1984, Letarte and Vaillancourt 1986, Mackie et al. 1980, Mackie 2000, Watson and Ormerod 2005).
Can live up to 3 years, mature at 4 mm (sexually mature as early as 3 months old in Europe). Individuals in the St. Lawrence River live to 1 or 1 and a half, while in Europe they can sometimes live to 2 or 3. S. corneum is hermaphroditic and ovoviviparous. Eggs incubated in a brood-sac in the parent; embryos develop and are released as miniature adults. Sexually mature adults can carry 1–20 embryos, occasionally more. Parturition in the St. Lawrence River usually occurs in the spring (Clarke 1981, Dussart 1979, Letarte and Vaillancourt 1986, Letarte and Vaillancourt 1988, Mackie 2000).
Sphaerium corneum is mainly a filter feeder but can also deposit feed. It prefers diatoms but also ingests other types of phytoplankton. Sphaerium corneum is capable of climbing up aquatic macrophytes, which aids it to filter feed (Bishop and DeGaris 1976, Mackie 2000). In Europe, S. corneum is host to Phyllodistomum spp., which are digenean parasites. The common toad Bufo bufo can aid S. corneum in dispersing in Europe, as the clam can attach to the amphibian’s toe and thus be transferred from one place to another (Kwet 1995, Petkeviciutie et al. 2004).
Means of Introduction:
Sphaerium corneum was likely introduced via shipping, probably in solid ballast that was in use at the turn of the century (Grigorovich et al. 2000, Grigorovich et al. 2003, Mills et al. 1993).
Status:
Established where recorded, but most common in Lake Erie and Lake Ontario, and uncommon in Lake Huron, where it is uncertain if populations are permanently established.
Great Lakes Impacts:
Summary of species impacts derived from literature review. Click on an icon to find out more...
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Current research on the environmental impact of Sphaerium corneum in the Great Lakes is inadequate to support proper assessment.
Potential:
In North America, Sphaerium corneum hosts such digenean species as Crepidostomum transmarinum, Bunodera lucipercae, and Phyllodistomum simile, which also parasitize fish, including salmonids. These species have been recorded from the Ottawa River, which flows into the St. Lawrence River in Canada (Mackie 1976, Mackie 2000).
There is little or no evidence to support that Sphaerium corneum has significant socio-economic impacts in the Great Lakes.
Potential:
Sphaerium corneum shells have reportedly caused blockages in one water supply plant in Britain, although this type of problem has not been reported frequently (Clarke 1987).
There is little or no evidence to support that Sphaerium corneum has significant beneficial effects in the Great Lakes.
Realized:
Sphaerium corneum has been used frequently to conduct research on accumulation rates and metabolism of toxic chemicals and contaminants (e.g., Borchert et al. 1997, Penttinen et al. 1996, Verrengia Guerrero et al. 2002).
Potential:
In Lake Ontario and Cayuga Lake (part of the Lake Ontario drainage in New York state), S. corneum has been recorded as a host to the oligochaete Chaetogaster limnaei limnaei. This oligochaete is probably quite widespread in North America, where it is typically a commensal of native snails, some other native Sphaerium spp., and at least one native limpet species (Barbour 1977).
Management:
Regulations (pertaining to the Great Lakes region)
There are no known regulations for this species.
Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
There are no known biological control methods for this species.
Physical
There are no known physical control methods for this species.
Chemical
A wide array of chemical molluscicides are available, but are not species-specific and may harm native species to a greater extent than non-natives.
Molluscicides are typically classified as either oxidizing or non-oxidizing compounds. Oxidizing chemicals include chlorine, chlorine dioxide, chloramines, ozone, bromine, hydrogen peroxide, and potassium permanganate. Non-oxidizing chemicals (including organic film-forming antifouling compounds, gill membrane toxins, and nonorganics) can be classified into several distinct groups: quanternary and polyquaternary ammonium compounds; aromatic hydrocarbons; endothall as the mono (N,N-dimethylalkyl amine) salt; metals and their salts (e.g., copper sulfate formulations); and niclosamide (including some formulations of Bayluscide). Bayluscide was initially developed as a sea lamprey larvicide, but has molluscicidal activity. While some of these products are biodegradable, many require detoxification or deactivation to meet state and Federal discharge requirements (USACE 2012).
In short-term experiments, S. corneum can reduce the bioaccumulation of 2,4,5-trichlorophenol (TCP) by closing their shell valves (Heinonen et al 1997) – this reaction to chemical stimuli generally may limit the usefulness of chemical molluscicides against this species.
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.
References
(click for full reference list)
Author:
Kipp, R.M., A.J. Benson, J. Larson, and A. Fusaro
Contributing Agencies:
Revision Date:
12/6/2019
Citation for this information:
Kipp, R.M., A.J. Benson, J. Larson, and A. Fusaro, 2024, Sphaerium corneum Linnaeus, 1758: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?Species_ID=131&Potential=N&Type=1&HUCNumber=DHuron, Revision Date: 12/6/2019, Access Date: 4/19/2024
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.