Pisidium amnicum
(Müller, 1774)
Common Name:
Greater European peaclam
Synonyms and Other Names:
Identification:
This small bivalve has a height to length ratio of 0.74–0.81 and is relatively long, oval shaped, and heavily striated with a shiny yellow or brown epidermis. The beaks are located towards the posterior by about 2/3 of the total shell length. Inside the shell, the cardinal teeth are closer to the anterior lateral teeth than to the posterior lateral teeth, the 2nd cardinal tooth is a thick peg covered by the thinner 4th cardinal, and the 3rd cardinal curves around the 2nd cardinal. In live specimens there is only an anal siphon (Clarke 1981, Herrington 1962, Mackie et al. 1980, Pennak 1989).
Size:
varies from 8.8 to 11.9 mm in length (Herrington 1962, Holopainen 1979, Holopainen et al. 1997, Vincent et al. 1981).
Native Range:
Pisidium amnicum is widely distributed in Eurasia and North Africa between Naples, Siberia, and Algiers (Mackie 2000, Por et al. 1986, Vincent et al. 1981).
Great Lakes Nonindigenous Occurrences:
Pisidium amnicum was first recorded in the Great Lakes drainage in 1897 near the mouth of the Genesee River at Lake Ontario. It has also been recorded from other areas in Lake Ontario, Lake Huron, Lake Erie, Lake Michigan, and Lake Superior (Clarke 1981, Grigorovich et al. 2003, Heard 1962, Mackie 2000, Mackie et al. 1980, Mills et al. 1993).
Also 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 Pisidium amnicum are found here.
Full list of USGS occurrences
Table last updated 5/1/2024
† Populations may not be currently present.
Ecology:
Found in freshwater lakes and slow-moving rivers with soft bottoms; water temperatures of 1–21ºC. Pisidium amnicum is typically a rheophilic species in its native range but can also occur in lakes. It prefers sand but has also been recorded on mud and gravel. It can survive anoxic conditions under ice cover but may be limited in some upper river reaches where temperatures do not exceed 15–17ºC in July. Pisidium amnicum is capable of closing its shell to induce anoxia, metabolic quiescence, and anaerobiosis, and can survive for 200 days at 0ºC. It occurs down to 30 m in Europe but only down to 10 m in the Great Lakes. Densities in Europe have reached around 1000–3300 clams per m2.
In the St. Lawrence River, Canada, where it has been introduced, it is often found living in littoral zones in association with the introduced snail Bithynia tentaculata and the oligochaete Sparganophilus tamesis (Bishop and Hewitt 1976, Holopainen 1979, 1987, Mackie et al. 1980, Vincent et al. 1981, Dyduch-Falniowska 1982, Piechocki and Luczak 1989, Holopainen and Penttinen 1993, Grabow 1994, Zettler 1997, 1998, Holopainen et al. 1997, Mackie 2000).
Pisidium amnicum can live up to 3 years, mature at 4 mm (sexually mature as early as 3 months old in Europe). It is hermaphroditic, ovoviviparous, and can undergo cross-fertilization. Eggs incubated in a brood-sac in the parent; embryos develop and are released as miniature adults. In Europe it is often semelparous, reproducing once in a lifetime. In the St. Lawrence River it is iteroparous, reproducing twice, once at age 2 and once at age 3. Recruitment takes place when water temperatures reach 15–20ºC. Maturation of individuals and egg-laying occur between July and October, and eggs are brooded for around 9–10 months. The number of embryos per adult varies from 5–29. Lifespan is typically 1–3 years (Araujo and Ramos 1999, Araujo et al. 1999, Holopainen 1979, Holopainen et al. 1997, Vincent et al. 1981).
Pisidium amnicum larvae may be distributed by ruminants via excrement. Adult clams in particular can be hosts to digenean parasites in Eurasia, such as: Bunodera lucipercae, Palacerochis crassus, Phyllodistomum elongatum, and Crepidostomum sp. Parasites may castrate their hosts. Semelparity could be a result of castration (Holopainen et al. 1997, Rantanen et al.1998, Sturm 2000, Zhokov 1990).
Pill clams are filter feeders (suspension feeders on algae and bacteria), living in the sediments and obtaining nutrition from the substrate and the water column. This species especially favors diatoms (Holopainen 1979, Mackie 2000).
Means of Introduction:
Pisidium amnicum was very likely introduced in solid ballast, which was used in the early 1900s in ships entering the Great Lakes (Mills et al. 1993; Grigorovich et al. 2003).
Status:
Established where recorded, but at low densities in some regions. Pisidium amnicum could also occur in other inland waters within the Great Lakes basin (Clarke 1981, Grigorovich et al. 2003, Mackie et al. 1980, Mills et al. 1993).
Great Lakes Impacts:
Current research on the environmental impact of Pisidium amnicum in the Great Lakes is inadequate to support proper assessment.
A recent report by Trebitz et al. (2010) speculated that significant adverse impacts from P. amnicum are not expected based on the limited extent of populations in both Lake Superior for the past 20 years and elsewhere in the Great Lakes.
There is little or no evidence to support that Pisidium amnicum has significant socio-economic impacts in the Great Lakes.
This species does not appear to have any impacts on human health or recreation.
There is little or no evidence to support that Pisidium amnicum has significant beneficial effects in the Great Lakes.
This species does not appear to have any significant commercial or research value.
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).
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.
Remarks:
In some parts of its native range P. amnicum is considered endangered (Beran 1998, Sturm 2000).
References
(click for full reference list)
Author:
Kipp, R.M., A.J. Benson, J. Larson, and A. Fusaro
Contributing Agencies:
Revision Date:
11/26/2019
Citation for this information:
Kipp, R.M., A.J. Benson, J. Larson, and A. Fusaro, 2024, Pisidium amnicum (Müller, 1774): 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=129&Potential=N&Type=0&HUCNumber=DGreatLakes, Revision Date: 11/26/2019, Access Date: 5/1/2024
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.