Invasion History

First Non-native North American Tidal Record: 1972
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 1972

General Invasion History:

Sphaerium corneum is a small deposit-feeding freshwater bivalve native to Eurasia (Herrington 1962; Kuiper et al. 1989). Published records range from France, the British Isles, Sweden and Finland to Poland and Lithuania (Kuiper et al.1989), including low-salinity regions of the Baltic Sea (Remane and Schleiper 1971; Zettler and Daunys 2007). It has been introduced to the Great Lakes, the Saint Lawrence River and Estuary, Lake Champlain, Lake George, and the Hudson River (Strayer 1987; Letarte and Vaillancourt 1988; Mills et al. 1993; Marsden 2009; USGS Nonindigenous Aquatic Species Program 2012).

North American Invasion History:

Invasion History on the East Coast:

Sphaerium corneum was first recorded in North America in 1924 in Lake Ontario (Duggan et al. 2003). Possible vectors of introduction include dry ballast and marsh grasses used as packing materials for fragile European goods. It is now found through the Great Lakes-St. Lawrence system, from Lake Superior (Grigorovich et al. 2003) to Lakes Erie and Ontario (Herrington 1962) and the upper St. Lawrence Estuary. In the St. Lawrence estuary, it ranges from the Lac St. Pierre Dam at the head of tide to Quebec City (Vincent 1979; LeTarte and Vaillancourt 1988).

Sphaerium corneum was reported from the Hudson River, near Albany, New York in 1972 by Simpson (1976, cited by Strayer 1987). Strayer found one shell near Kingston in 1987, but considered that the presence of this clam required confirmation, given difficulties of identification (Strayer 1987; Mills et al. 1993). This clam was found in Lake George, in the upper Hudson basin, in 2007 (USGS Nonindigenous Aquatic Species Program 2012).


Sphaerium corneum is a member of the family Pisidiidae (Pea Clams), which are minute freshwater clams, ranging from 1 to 25 mm in length. In the genus Sphaerium, the beak is at about the midpoint of the shell and two siphons, an oral and branchial siphon, are fully developed. The shell is thin, somewhat inflated, and looks like a compressed sphere in a view from the ends (Martin 1998). In S. corneum, the shell is oval, with a height of 0.74 - 0.81 of the length. Herrington's North American specimens ranged up to 8.6 mm in length, but he noted that European specimens were often larger, up to 13.5 mm (Herrington 1962). The beak is low, broad, and slightly anterior to the midpoint. The anterior dorsal edge is slightly curved, while the posterior end slopes more steeply, and is more strongly curved. The shell is covered with evenly spaced growth lines which become faint toward the beak. The hinge plate is rather long. The narrow and curved 3rd cardinal is parallel to the hinge plate, expanded, and often bifurcated posteriorly. The narrow 4th and 2nd cardinal teeth are very close to parallel and the former overlaps the latter. The shell is brown to gray (Herrington 1962; Clarke 1981).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Mollusca
Class:   Bivalvia
Subclass:   Heterodonta
Order:   Veneroida
Superfamily:   Corbiculoidea
Family:   Pisidiidae
Genus:   Sphaerium
Species:   corneum


Tellina cornea (Linnaeus, 1758)

Potentially Misidentified Species

Spaherium nitidum
This clam has a Holarctic distribution (Herrington 1962).



Sphaerium corneum is a small deposit-feeding freshwater clam, which burrows in the sediment of rivers, streams, and lakes. Fingernail clams are hermaphroditic and oviviparous, 'giving birth' to shelled juveniles (Martin 1998). In the St. Lawrence River, S. corneum started carrying embryos at 4.0 mm in size. The numbers of embryos increased with body size, but varied temporally, from 4 embryos for a 9 mm clam in August 1983 to highs of 9-10 for a same-sized clam in November 1983 and June 1984. The highest fecundity seen was 13 embryos (Letarte and Vaillancourt 1988). Annual fecundity is estimated at 63 embyos per female (Keller et al. 2007).

Sphaerium corneum is a freshwater species, but occurs at salinities of at least 3 PSU (Remane and Schleiper 1971; Zettler and Daunys 2007). Fingernail Clams feed by filtering detritus and particles in interstitial waters (Thorp and Covich 2001). As a group, fingernail clams are an important food for benthic invertebrates and fishes (Martin 1998).


Detritus, benthic diatoms

Trophic Status:

Deposit Feeder



General HabitatUnstructured BottomNone
Salinity RangeLimnetic0-0.5 PSU
Salinity RangeOligohaline0.5-5 PSU
Tidal RangeSubtidalNone
Vertical HabitatEndobenthicNone

Tolerances and Life History Parameters

Minimum Salinity (‰)0This is a freshwater species.
Maximum Salinity (‰)3Field, Baltic Sea, Remane and Schlieper 1971
Minimum Length (mm)4Minimum reproductive size, St. Lawrence River (Letarte and Vaillancourt 1988).
Maximum Length (mm)13.5European specimens, cited by Herrington (1962). Clams from the St. Lawrence River reached 10 mm (Letarte and Vaillancourt 1988).
Broad Temperature RangeNoneCold temperate
Broad Salinity RangeNoneNontldal Limnetic-Oligohaline

General Impacts

Sphaerium corneum is common in the St. Lawrence River Estuary and widespread in the Great Lakes (Herrington 1962; Letarte and Vaillancourt 1988). However, no ecological or economic impacts have been reported for this species.

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
GL-III Lake Ontario 1924 Def Estab
GL-II Lake Erie 1951 Def Estab
M060 Hudson River/Raritan Bay 1972 Def Unk
NA-S3 None 1977 Def Estab
GL-I Lakes Huron, Superior and Michigan 2001 Def Estab
B-XIII None 0 Native Estab
B-IX None 0 Native Estab
B-VII None 0 Native Estab
L101 _CDA_L101 (Grand) 1951 Def Estab
L013 _CDA_L013 (St. Louis River) 2001 Def Estab
L014 _CDA_L014 (Beartrap-Nemadji) 2001 Def Estab
L018 _CDA_L018 (Portage River) 2001 Def Estab
L061 _CDA_L061 (St. Marys) 2001 Def Estab
L127 _CDA_L127 (English-Salmon) 1971 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


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

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