The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Eupera cubensis
(mottled fingernailclam)
Native Transplant

Copyright Info
Eupera cubensis

Common name: mottled fingernailclam

Taxonomy: available through www.itis.govITIS logo

Size: Small, 3-8 mm in length (Heard 1965)

Native Range: Fresh waters of the Atlantic drainage from Texas to North Carolina, and in Central and northern South America (Heard 1965).

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, 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 Eupera cubensis are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
IL200620061Des Plaines
WV200920111Upper Monongahela

Table last updated 7/17/2024

† Populations may not be currently present.

Means of Introduction: Unknown

Status: Established in Illinois.

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

Remarks: This species has a functional byssal gland (Heard 1977 as cited in Mackie 2007).

References: (click for full references)

Heard, W. H. 1965. Recent Eupera (Pelecypoda: Sphaeriidae) in the United States. Am. Midl. Nat. 74(2):309-317.

Heard, W. H. 1977. Reproduction of fingernail clams (Sphaeriidae: Sphaerium and Musculium). Malacologia 16: 421-455.

Mackie, G. L. 2007. Biology of freshwater Corbiculid and Sphaeriid clams of North America. Ohio Biological Survey Bulletin New Series. Volume XV Number 3 ix+436 p.

Sneen, M. E., K. S. Cummings, T. Minarik, Jr., and J. Wasik. 2009. The discovery of the nonindigenous, mottled fingernail clam, Eupera cubensis (Prime, 1865) (Bivalvia: Sphaeriidae) in the Chicago Sanitary and Ship Canal (Illinois River Drainage), Cook County, Illinois. J. Great Lakes Res. 35(4):627-629.

Author: Benson, A.J.

Revision Date: 6/29/2023

Citation Information:
Benson, A.J., 2024, Eupera cubensis: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=2778, Revision Date: 6/29/2023, Access Date: 7/18/2024

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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/18/2024].

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