Mussel Species

Freshwater Mussels of the New York Metro Area and New Jersey

Genera: Alasmidonta | Anodonta | Corbicula | Dreissena | Elliptio | Lampsilis | Lasmigona | Leptodea | Ligumia | Margaritifera | Pyganodon | Strophitus | Utterbackia

Genus Alasmidonta

Family Unionidae

Of the five species in this genus known to occur in New York state, the metro area has three: A. heterodonA. undulata and A. varicosa. The other two species have ranges that reach only western and central New York state. Of the three species in this area, A. heterodon is listed as both a state and federal endangered species in New York, New Jersey and Connecticut. It is currently known from only a few sites in the metro area. A. varicosa has declined from its formerly widespread status; it is listed as threatened in New York, and as endangered in New Jersey and Connecticut. A. undulata is regarded as a species of special concern by some workers, although it is not yet legally protected in any of the three states.

Alasmidonta heterodon (Lea, 1830)

Dwarf wedgemussel

Alasmidonta undulata (Say, 1817)

Triangle floater

Alasmidonta varicosa (Lamarck, 1819)

Brook floater

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Genus Anodonta

Family Unionidae

One species of Anodonta occurs in the metro area and adjacent New Jersey. The native species Anodonta implicata is known in the two metro area from two populations, until recently abundant in the Hudson and Delaware Rivers of New York. These are reported by local biologists to be in decline - presumably affected by the proliferation of the zebra mussel Dreissena polymorpha. The current status of A. implicata in the Connecticut River and in New Jersey portions of the Delaware River is unknown. A. implicata is not legally protected by the US or the states of the metro area.

Anodonta implicata (Say, 1829)

Alewife floater

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Genus Corbicula

Family Corbiculidae

Our only representative of the family Corbiculidae is the invasive species Corbicula fluminea (Muller, 1774), the asiatic clam. Although widely distributed in the US, C. fluminea is limited in the NY metro area to several lakes on Long Island, NY, and to Twin Lakes, CT, and in NJ is present in all major waterways outside the Pine Barrens.

Corbicula fluminea (Muller, 1774)

Asiatic clam

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Genus Dreissena

Family Dreissendae

Two species of the genus Dreissena occur in North America. Both are established invasives. D. bugensis is confined to the eastern Great Lakes and the St. Lawrence River, and reaches only the northern edge of the region. It does not occur in the metro area. By contrast, the zebra mussel D. polymorpha is abundant in the metro area, and is distributed widely throughout the eastern and midwestern US, reaching from Quebec (Canada) south on the Atlantic slope to Georgia, and west to Minnesota, Oklahoma and Louisiana.

Note: Although not extralimital to the metro area, D. polymorpha is described here with its sister species for convenience; it is also included among the descriptions of the other metro area species.

Dreissena bugensis (Andrusov, 1897)

Quagga mussel

Dreissena polymorpha (Pallas, 1771)

Zebra mussel

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Genus Elliptio

Family Unionidae

Widespread and abundant, utilizing a variety of hosts, and occuring in most watersheds in the metro area, Elliptio complanata is one of our most familiar freshwater mussels. A second common and widely adapted species of ElliptioE. dilatata, reaches western New York State drainages but is not recorded from the metro area.

Elliptio complanata (Lightfoot, 1786)

Eastern elliptio

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Genus Lampsilis

Family Unionidae

Seven Lampsilis species are recorded from New York State, of which two are known from the metro area: Lampsilis cariosa, and L. radiata. Both have wide distributions along the Atlantic slope where they remain generally common to abundant. In the metro area however both species are much less common, and L. cariosa is listed as a species of Special Concern in Connecticut. Lampsilis abrupta, which also occurs in New York State, is Federally listed as Endangered.

Lampsilis cariosa (Say, 1817)

Yellow lampmussel

Lampsilis radiata (Gmelin, 1791)

Eastern lampmussel

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Genus Lasmigona

Family Unionidae

Lasmigona subviridis, the green floater, ranges from the Carolinas to the Hudson River basin and the St. Lawrence in New York. In New Jersey, the species once occurred in the Delaware-Raritan Canal and the Passaic, Raritan, Delaware and Pequest rivers. In 1996, a single live individual was found in Stony Brook, Mercer County. The Stony Brook occurrence represents the only reported sighting of a live green floater in the state since the early 1900's. The green floater is listed as endangered in NJ.

Lasmigona subviridis (Conrad, 1835)

Green floater

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Genus Leptodea

Family Unionidae

Until the early 1990's, L. ochracea, the only member of Leptodea that occurs in the metro area, was a common to abundant species in the tidal Hudson River above the salt plume, and a characteristic resident of coastal tidal waters along the eastern seaboard. It now appears to be in serious decline, possibly due to the proliferation of Dreissena polymorpha, the zebra mussel. Today considered rare in our area by some workers, it has been assigned Threatened status in Connecticut, and was described as a species of Special Concern in (Williams, et al) 1993.

Leptodea orchracea (Say, 1817)

Tidewater mucket

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Genus Ligumia

Family Unionidae

Two species of Ligumia occur in New York state. Only L. nasuta reaches the metro area, occuring in scattered locations in the Hudson, Delaware, and Housatonic rivers. It is more common in western New York state. Although considered by some researchers to be a species of special concern, L. nasuta is not legally protected in the metro area.

Ligumia nasuta (Say, 1817)

Eastern pondmussel

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Genus Margaritifera

Family Margaritiferidae

Formerly common in the Hackensack River and known from the Delaware River watershed, M. margaritifera today may be extirpated from the Hackensack River and is rare everywhere else in the metro area; it is apparently extirpated from New York State within the metro area, although still present in several other NY localities. It may remain common in restricted mountain stream habitats in the Appalachians (Strayer, 1994).

Margaritifera margaritifera (Linneaus, 1758)

Eastern pearlshell

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Genus Pyganodon

Family Unionidae

Pyganodon is a genus of several very similar species whose exact relationship and distribution in New York state remain unresolved. In the metro area, only Pyganodon cataracta is believed to occur. It is widespread in the upper Hudson and Delaware River watersheds, and in other areas of New Jersey, New York state, Connecticut and the Atlantic region.

Pyganodon cataracta (Say, 1817)

Eastern floater

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Genus Strophitus

Family Unionidae

Strophitus undulatus remains a common to abundant species in most of the metro area and throughout its range. However, in New Jersey it is designated a species of special concern. It occurs from Nova Scotia to Georgia on the Atlantic slope, and west to Saskatchewan and Texas, thriving in small, slow-moving water as well as larger rivers and lakes. S. undulatus is the only species of Strophitus occurring in the Atlantic region.

Strophitus undulatus (Say, 1817)


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Genus Utterbackia

Family Unionidae

Utterbackia imbecillis is an introduced species, widespread and successful throughout central and southern North America, and now present in the Northeast region. Metro populations are apparently confined to the lower Delaware River watershed in New Jersey. It reportedly uses a wide range of host species, but can reproduce without glochidial parasitism. U. imbecillis is not legally protected by the US or the states of the metro area.

Utterbackia imbecillis (Say, 1829)

Paper pondell

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