Black Sandshell

Ligumia recta (Lamarck, 1819)

Black Sandshell (Ligumia recta)
Carnegie Museum of Natural History

Bivalvia (Bivalves)
Unionidae (Unionid Mussels)
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
Imperiled in New York - Very vulnerable to disappearing from New York due to rarity or other factors; typically 6 to 20 populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines.
Global Conservation Status Rank
Apparently or Demonstrably Secure globally - Uncommon to common in the world, but not rare; usually widespread, but may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign either G4 or G5.


Did you know?

The thick, lustrous shell of this species was highly valued by the pearl button industry in the early 1900s.

State Ranking Justification

This species is currently known from only 7 different creeks or rivers statewide and of those only 2 or 3 consist of healthy, viable populations. Although it has been found more recently in creeks where it was not formerly known in western New York, some of these are only old weathered shells or of poor population viability and likely do not represent range expansions, but rather increased survey effort. The primary host fish species (Sauger) itself is rare and narrowly distributed in the state.

Short-term Trends

It appears that this species was never common in New York. However, because of the widespread degradation of water quality since the industrialization of the state it can be safely assumed that this species previously had a much wider distribution, and higher abundance levels. Seventy-three percent of the records shown by Strayer and Jirka (1997) are from pre-1970. Black Sandshells were already apparently very uncommon in both the Great Lakes (Schloesser and Nalepa 1994) and St. Lawrence (Ricciardi et al. 1996) basins prior to the Zebra Mussel invasion.

Long-term Trends

Strayer and Jirka (1997) suggested that because much of this species' range had not been adequately surveyed, its status wasn't well known. More recent surveys in western New York have found them in creeks from which they were not previously known (Marangelo and Strayer 2000).

Conservation and Management


The single most important cause of the decline of freshwater mussels during the last century is the destruction of their habitat by siltation, dredging, channelization, impoundments, and pollution. A healthy fish assemblage is critical to viable mussel populations and dams have resulted in heavy losses of mussels, mainly due to elimination of host fish species. Rarity and decline in New York of the primary host fish species (Sauger) is likely to account for the ongoing threats to this mussel (Khym and Layzer 2000). Erosion due to deforestation, poor agricultural practices and the destruction of riparian zones, causes an increase in siltation and shifting substrates that can smother mussels. Domestic sewage, effluents from paper mills, tanneries, chemical industries and steel mills, acid mine runoff, heavy metals, and pesticides have all been implicated in the destruction of the native mussel fauna.

Conservation Strategies and Management Practices

The effects of PCBs and other toxic chemicals, and general water pollution, should be investigated for their potential role in the decline of this species. When feasible, the removal of impoundments in order to restore rivers to their natural flow would be beneficial since these structures negatively affect required fish host species as well as the mussels themselves. Khym and Layzer (2000) suggested that infecting any sportfish (especially Sauger/Walleye) with glochidia prior to release could be a good opportunity to augment populations.

Research Needs

There is still much to learn about this species in New York, especially determination of the primary host fish species and whether the closely related Walleye and Sauger can serve equally well as primary hosts. Details about habitat requirements (current speed, water depth, substrate grain size, substrate stability, water temperature, and water quality factors) also need work. However, Strayer et al. (1994) found that the distribution of Unionids was not related to these typical physical habitat qualities, but instead was related to long term stability of the substrate (i.e., flow refuges) and other large-scale habitat variables such as riparian zone vegetation (i.e., grassy vs. forested). Both large and smaller scale forces promoting the patchy occurrence of Unionid mussel beds is an active area of research (Strayer et al. 2004).



Black Sandshells are typically found in medium-sized to large creeks and rivers in locations with a strong current and substrates of coarse sand and gravel with cobbles in water depths from several inches to six feet or more (Parmalee and Bogan 1998).

Associated Ecological Communities

  • Confined river (guide)
    The aquatic community of relatively large, fast flowing sections of streams with a moderate to gentle gradient.

Associated Species

  • Mucket (Actinonaias ligamentina)
  • Elktoe (Alasmidonta marginata)
  • Threeridge (Amblema plicata)
  • Eastern Elliptio (Elliptio complanata)
  • Spike (Elliptio dilatata)
  • Snuffbox (Epioblasma triquetra)
  • Wabash Pigtoe (Fusconaia flava)
  • Plain Pocketbook (Lampsilis cardium)
  • Yellow Lampmussel (Lampsilis cariosa) (guide)
  • Wavyrayed Lampmussel (Lampsilis fasciola)
  • Pocketbook (Lampsilis ovata)
  • Eastern Lampmussel (Lampsilis radiata)
  • Fatmucket (Lampsilis siliquoidea)
  • Creek Heelsplitter (Lasmigona compressa)
  • Flutedshell (Lasmigona costata)
  • Eastern Pondmussel (Ligumia nasuta) (guide)
  • Round Pigtoe (Pleurobema sintoxia)
  • Pink Heelsplitter (Potamilus alatus)
  • Fragile Papershell (Potamilus fragilis)
  • Kidneyshell (Ptychobranchus fasciolaris)
  • Giant Floater (Pyganodon grandis)
  • Creeper (Strophitus undulatus)
  • Deertoe (Truncilla truncata)
  • Rayed Bean (Villosa fabalis)


New York State Distribution

There are three general areas of occupancy in New York, reflecting the routes of entry into the state: the Allegheny, Great Lakes, and Champlain basins (Strayer and Jirka 1997). Within the Allegheny drainage the species is known from the Allegheny River in the vicinity of Olean and Portville, as well as two of its major tributaries, the Cassadaga and Conewango creeks. In the Great Lakes basin, there are old records from Lake Erie, but more recently a thriving population was located in Tonawanda Creek along the border of Niagara and Erie counties (Marangelo and Strayer 2000). Several pre-1970 records are also known from the Erie Canal and Oneida Lake (Strayer and Jirka 1997) and shells were found in 1993 and 2008 (Mahar and Landry 2020). Live mussels were found south of Oneida Lake, in Chittenago Creek at Bridgeport. The St. Lawrence basin population seems to be the most precarious, since only pre-1970 records are known from the St. Lawrence River (Strayer and Jirka 1997), and small population are found in the Grass, Oswegatchie, and Raquette rivers. Finally, a small population also occurs on the Poultney River, a tributary of Lake Champlain. Sauger was found to be the primary host for this mussel (Khym and Layzer 2000) and the mussel's distribution within the state does follow the general distribution this rare fish.

Global Distribution

This species is widespread in the eastern and central U.S. and Canada, occurring from the Great Lakes basin south into the Mississippi River drainage to Louisiana and in some Gulf Coast drainages (Parmalee and Bogan 1998).

Best Places to See

  • Tonawanda Creek (Niagara County)

Identification Comments

General Description

This mussel has a thick, subelliptical, elongate shell reaching about 20 cm long. The periostracum is dark green and shiny with rays in younger animals, but in older specimes it is dark brown to black. The hinge teeth are heavy; pseudocardinals triangular or slightly compressed. The nacre is most often white, but can be pinkish or purple. The shells of females are broader and more rounded posteriorly than those of the males (Strayer and Jirka 1997).

Identifying Characteristics

The shells of this species are distinctively large, heavy, and elongate with a black periostracum and strong hinge teeth (Strayer and Jirka 1997).

Best Life Stage for Proper Identification



Adults of this species are sessile with only limited movement in the substrate. Passive downstream movement may occur when they are displaced from the substrate during floods. More major dispersal occurs while glochidia are encysted on their host(s). Being ectothermic, activity levels of mussels are presumably reduced greatly during colder months of the year. Gravid females of Ligumia display marginal papillae to attract fish hosts for their parasitic larvae. The moving displays attract fish which readily attack displaying females, causing them to release glochidia onto the gills of the fish (Corey et al. 2006).


Adult mussels are filter feeders. Algae, detritus and bacteria are all important food sources. Mussels in turn are eaten by muskrats, raccoons, fish, and birds. The glochidial (larval) host fish species include the Banded Killifish, White Crappie, Largemouth Bass, Bluegill, Green Sunfish, Orangespotted Sunfish, and Walleye (Strayer and Jirka 1997). Khym and Layzer (2000) reported that Sauger was the most suitable host species.

Best Time to See

Little is known about the activity periods of Unionid mussels but they are presumed to be greatly reduced during cold times of the year. Freshwater mussels are most often easiest to locate during late summer when water levels are lowest. This species is a long-term breeder; its gravid period overlaps in different individuals and extends nearly year round (Clarke 1981).

  • Reproducing

The time of year you would expect to find Black Sandshell reproducing in New York.

Similar Species

  • Spike (Elliptio dilatata)
    This species is noticeably smaller than L. recta, but younger black sandshells may be confused. Ligumia recta has a shiny green or black periostracum, while that of E. dilitata is rougher and browner.

Black Sandshell Images


Black Sandshell
Ligumia recta (Lamarck, 1819)

  • Kingdom Animalia
    • Phylum Mollusca (Mollusks)
      • Class Bivalvia (Bivalves)
        • Order Unionoida (Freshwater Mussels)
          • Family Unionidae (Unionid Mussels)

Additional Resources


Burch, J.B. 1975. Freshwater unionacean clams (mollusca: pelecypoda) of North America. Malcological Publications. Hamburg, Michigan. 204 pp.

Clarke, A.H. 1981a. The freshwater mollusks of Canada. National Museum of Natural Sciences, National Museums of Canada, D. W. Friesen and Sons, Ltd.: Ottawa, Canada. 446 pp.

Clarke, A.H. and C.O. Berg. 1959. The freshwater mussels of central New York. Cornell University Agricultural Experiment Station Memoir 367.

Corey, C.A., R. Dowling, and D.L. Strayer. 2006. Display behavior of Ligumia (Bivalvia: Unionidae). Northeastern Naturalist 13:319-332.

Khym, J.R. and J.B. Layzer. 2000. Host fish suitability for glochidia of Ligumia recta. American Midland Naturalist 143: 178-184.

Marangelo, P.J. and D.L. Strayer. 2000. The freshwater mussels of the Tonawanda Creek basin in western New York. Walkerana, 11(25): 97-106.

New York Natural Heritage Program. 2023. New York Natural Heritage Program Databases. Albany, NY.

New York State Department of Environmental Conservation. 2020. ArcGIS layer package on mussel records in New York State.

Parmalee, P.W. and A.E. Bogan. 1998. The Freshwater Mussels of Tennessee. University of Tennessee Press: Knoxville, Tennessee. 328 pp.

Ricciardi, A., F.J. Whoriskey, and J.B. Rasmussen. 1996. Impact of Dreissena invasion on native unionid bivalves in the upper St. Lawrence River. Canadian Journal of Fisheries and Aquatic Science, 53: 1434-1444.

Robertson, I. and C. Blakeslee. 1948. The mollusca of the Niagara Frontier region. Bulletin Buffalo Society Natural Science 19: 1-191.

Schloesser, D.W., and T.F. Nalepa. 1994. Dramatic decline of Unionid bivalves in offshore waters of western Lake Erie after infestation by the zebra mussel, Dreissena polymorpha. Canadian Journal of Fisheries and Aquatic Science 51:2234-2242.

Strayer, David L. and K.J. Jirka. 1997. The Pearly Mussels (Bivalva: Unionoidea) of New York State. New York State Museum Memoir 26. The New York State Education Department.

Strayer, David L., D.C. Hunter, L.C. Smith, and C.K. Borg. 1994. Distribution, abundance, and roles of freshwater clams (Bivalva, Unionidae) in the freshwater tidal Hudson River. Freshwater Biology 31:239-248.

Strayer, David L., J.A. Dowling, W.R. Haag, T.L. King, J.B. Layzer, T.J. Newton and S.J. Nichols. 2004. Changing perspectives on Pearly Mussels, North America's most Imperiled Animals. BioScience 54:429-439.


About This Guide

Information for this guide was last updated on: March 5, 2009

Please cite this page as:
New York Natural Heritage Program. 2023. Online Conservation Guide for Ligumia recta. Available from: Accessed December 8, 2023.