Ligumia nasuta - (Say, 1817)
Eastern Pondmussel
Synonym(s): Sagittunio nasutus (Say, 1817)
Taxonomic Status: Accepted
Related ITIS Name(s): Ligumia nasuta (Say, 1817) (TSN 80195)
French Common Names: ligumie pointue
Unique Identifier: ELEMENT_GLOBAL.2.117973
Element Code: IMBIV26010
Informal Taxonomy: Animals, Invertebrates - Mollusks - Freshwater Mussels
 
Kingdom Phylum Class Order Family Genus
Animalia Mollusca Bivalvia Unionoida Unionidae Ligumia
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Concept Reference
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Concept Reference: Turgeon, D.D., J.F. Quinn, Jr., A.E. Bogan, E.V. Coan, F.G. Hochberg, W.G. Lyons, P.M. Mikkelsen, R.J. Neves, C.F.E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F.G. Thompson, M. Vecchione, and J.D. Williams. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland: 526 pp.
Concept Reference Code: B98TUR01EHUS
Name Used in Concept Reference: Ligumia nasuta
Taxonomic Comments: Watters (2018) places this species in the new genus Sagittunio (as S. nasutus), here maintained as a synonym.
Conservation Status
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NatureServe Status

Global Status: G4
Global Status Last Reviewed: 31Dec2011
Global Status Last Changed: 10Apr2007
Rounded Global Status: G4 - Apparently Secure
Reasons: This is a widespread species that once was locally abundant from the Great Lakes to much of the Atlantic Slope, but has experienced decline in most areas (significantly so in the Canadian Great Lakes to New York, and New England) although still maintains hundreds, if not thousands, of populations across its range.
Nation: United States
National Status: N4 (10Apr2007)
Nation: Canada
National Status: N1 (01Aug2017)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Connecticut (S2), Delaware (S1), District of Columbia (SNR), Maryland (S1S2), Massachusetts (S3), Michigan (S2), New Hampshire (S1), New Jersey (S2), New York (S2S3), North Carolina (S2), Ohio (S1), Pennsylvania (S2S3), Rhode Island (S1), South Carolina (S2), Virginia (S3), Wisconsin (SU)
Canada Ontario (S1)

Other Statuses

Canadian Species at Risk Act (SARA) Schedule 1/Annexe 1 Status: E (07Mar2013)
Committee on the Status of Endangered Wildlife in Canada (COSEWIC): Special Concern (28Apr2017)
Comments on COSEWIC: Reason for designation: This medium to large freshwater mussel is widely distributed across southern Ontario, where it occurs in isolated wetland patches and inland lakes at low abundance. Following past declines in abundance it appears to have been extirpated from the offshore waters of lakes Erie and St. Clair, although there is a large remnant sub?population in the St. Clair River delta. Threats from invasive species include those from Zebra and Quagga mussels as well as European Common Reed. Other threats include pollution from wastewater discharge, and agricultural and industrial effluents. Recent surveys have located new subpopulations at 17 sites not known at the time of the previous assessment, some of which are currently free of Zebra and Quagga mussels. The increase in sampling effort, the apparent reduction in the rate of decline, and the discovery of new subpopulations since the previous assessment have contributed to the change in status for this species from Endangered to Special Concern.

Status history: Designated Endangered in April 2007. Status re?examined and designated Special Concern in April 2017.

IUCN Red List Category: NT - Near threatened
American Fisheries Society Status: Special Concern (01Jan1993)

NatureServe Global Conservation Status Factors

Range Extent: 200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Range Extent Comments: This species ranges from Lake Ontario and Lake Erie in Canada and Minnesota south and east to the Atlantic drainages in North Carolina. Although widespread, it is declining in many places particularly Canadian Great Lakes (Johnson, 1970). Recently this species has been confirmed to be likely extirpated from the main channel of the Detroit River between Lake St. Clair and Lake Erie, Michigan/Ontario; due to zebra mussel invasion (Schloesser et al., 2006).

Area of Occupancy: 2,501 to >12,500 4-km2 grid cells
Area of Occupancy Comments:  

Number of Occurrences: 81 - 300
Number of Occurrences Comments: Recently this species has been confirmed to be likely extirpated from the main channel of the Detroit River between Lake St. Clair and Lake Erie, Michigan/Ontario; due to zebra mussel invasion (Schloesser et al., 2006), though documented historically in the Clinton River (Strayer, 1980). In Rhode Island, it is only found within the Pawcatuck River basin (Raithel and Hartenstein, 2006). In Massachusetts, this species is uncommon in natural "great" ponds and lowland streams of most coastal drainage systems and in the Connecticut River (Smith, 2000). In Connecticut, it is known from the Connecticut River watershed and historically in the south central coast watershed (Nedeau and Victoria, 2003; J. Cordeiro, pers. comm., 2006). It does not occur in Maine (Nedeau et al., 2000). In Maryland, it is known from the Upper Potomac, Washington Metro, Choptank, and Pocomoke River drainages (Bogan and Proch, 1995). Bogan and Alderman (2004) list South Carolina distribution as historically from the Savannah River basin and from the Pee Dee, and Cooper-Santee River basins with an extant population in the Savannah River basin in Georgia documented. It is found in low numbers in two locations (Great Pee Dee River) in Pee Dee River drainage in South Carolina (Catena Group, 2006). In North Carolina, it is known from the Pee Dee, Cape Fear, Pamlico, Roanoke, and Chowan (Alderman and Alderman, 2009) River basins (Bogan, 2002) in Anson, Bertie, Brunswick, Chowan, Gates, Hertford, Nash (extirpated), Pitt (extirpated), Richmond, and Washington Cos. (LeGrand et al., 2006). In Ohio, it has entered Lake Erie and the Cuyahoga River (Watters, 1995) and Bass Islands of Lake Erie and much of Lake Erie proper with Muskingum River records probably erroneous (Watters et al., 2009). In Canada, this species is uncommon and declining and only occurs in Ontario where it is threatened severely by zebra mussels (Metcalfe-Smith and Cudmore-Vokey, 2004). It has been lost from nearly all its former range in Canada, but still occurs in the delta area of Lake St. Clair and a recent population in Lyn Creek (tributary of upper St. Lawrence River) near the outlet of Lake Ontario (COSEWIC, 2007). Historical Ontario distribution included Lake Ontario, Lake Erie, Lake St. Clair and their basins (Clarke, 1981).

Population Size: 100,000 to >1,000,000 individuals
Population Size Comments: In the Pee Dee River basin in South Carolina, this species was only found at two locations (Great Pee Dee River, Little Pee Dee River) in very low numbers (Catena Group, 2006).

Number of Occurrences with Good Viability/Integrity: Unknown

Overall Threat Impact: High
Overall Threat Impact Comments: The greatest threat to Canadian populations is the invasive zebra mussel as 90% of historical records are from zebra mussel infested waters (Metcalfe-Smith and Cudmore-Vokey, 2004). Zebra mussels constitute the most significant threat to the continued existence of this species in Canada (COSEWIC, 2007).

Short-term Trend: Decline of 10-30%
Short-term Trend Comments: In Canada, over 93% of historical records (occurs in Ontario only) are threatened by zebra mussels (COSEWIC, 2007; Metcalfe-Smith and Cudmore-Vokey, 2004). In Canada, this species is uncommon and declining and only occurs in Ontario where it is threatened severely by zebra mussels (Metcalfe-Smith and Cudmore-Vokey, 2004). It has been lost from nearly all its former range in Canada, but still occurs in the delta area of Lake St. Clair and a recent population in Lyn Creek (tributary of upper St. Lawrence River) near the outlet of Lake Ontario (COSEWIC, 2007). This species has experienced some declines, particularly in New England (Nedeau et al., 2000), northern and western New York (Strayer and Jirka, 1997), and Canada as well as some Atlantic slope states such as South Carolina (Catena Group, 2006). Recently this species has been confirmed to be likely extirpated from the main channel of the Detroit River between Lake St. Clair and Lake Erie, Michigan/Ontario; due to zebra mussel invasion (Schloesser et al., 2006).

Long-term Trend: Decline of 30-50%
Long-term Trend Comments: This species has experienced some declines, particularly in New England (Nedeau et al., 2000) and Canada as well as some Atlantic slope states. It was historically known from Ohio in the Black River (Lyons et al., 2007). Nearly all of its former range in Canada has been lost as this species was once one of the most common species of freshwater mussel in the lower Great Lakes (COSEWIC, 2007).

Intrinsic Vulnerability: Not intrinsically vulnerable

Environmental Specificity: Narrow to moderate.
Environmental Specificity Comments: This species inhabits protected areas of coastal lakes and ponds, in slackwater areas of rivers, slow moving streams, and in canals in a wide range of substrates (Nedeau et al., 2000).

Other NatureServe Conservation Status Information

Distribution
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Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) This species ranges from Lake Ontario and Lake Erie in Canada and Minnesota south and east to the Atlantic drainages in North Carolina. Although widespread, it is declining in many places particularly Canadian Great Lakes (Johnson, 1970). Recently this species has been confirmed to be likely extirpated from the main channel of the Detroit River between Lake St. Clair and Lake Erie, Michigan/Ontario; due to zebra mussel invasion (Schloesser et al., 2006).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States CT, DC, DE, MA, MD, MI, NC, NH, NJ, NY, OH, PA, RI, SC, VA, WI
Canada ON

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
CT Hartford (09003), Litchfield (09005), Middlesex (09007), New Haven (09009), New London (09011)
DE Sussex (10005)
MA Barnstable (25001), Bristol (25005), Essex (25009), Franklin (25011), Hampden (25013)*, Hampshire (25015), Middlesex (25017), Norfolk (25021), Plymouth (25023), Suffolk (25025)*
MD Worcester (24047)
MI Alcona (26001)*, Alger (26003)*, Arenac (26011)*, Bay (26017)*, Benzie (26019)*, Cheboygan (26031), Emmet (26047), Huron (26063)*, Iosco (26069), Macomb (26099)*, Monroe (26115), Montcalm (26117), Montmorency (26119)*, Ogemaw (26129)*, Presque Isle (26141), Roscommon (26143), Saginaw (26145)*, St. Clair (26147), St. Joseph (26149)*, Tuscola (26157)*, Wayne (26163)
NC Anson (37007), Bertie (37015), Brunswick (37019)*, Chatham (37037), Chowan (37041), Columbus (37047), Gates (37073), Halifax (37083), Hertford (37091), Martin (37117), Montgomery (37123), Nash (37127)*, Northampton (37131), Pitt (37147), Richmond (37153), Stanly (37167), Washington (37187)
NH Cheshire (33005), Hillsborough (33011), Rockingham (33015)
NJ Burlington (34005), Camden (34007), Cumberland (34011), Gloucester (34015), Mercer (34021), Middlesex (34023), Salem (34033), Somerset (34035), Sussex (34037)*
NY Albany (36001)*, Cattaraugus (36009)*, Chautauqua (36013), Columbia (36021), Dutchess (36027), Erie (36029), Livingston (36051), Monroe (36055), Ontario (36069), Orleans (36073), Wayne (36117)
OH Ashtabula (39007)*, Erie (39043)*, Geauga (39055), Lorain (39093)*, Lucas (39095)*, Ottawa (39123), Portage (39133), Sandusky (39143)*
PA Crawford (42039), Erie (42049), Mercer (42085), Philadelphia (42101)*, Warren (42123)
RI Providence (44007)*
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
01 Merrimack (01070002)+, Concord (01070005)+, Merrimack (01070006)+, West (01080107)+, Middle Connecticut (01080201)+, Lower Connecticut (01080205)+, Farmington (01080207)+, Charles (01090001)+, Cape Cod (01090002)+, Narragansett (01090004)+, Quinebaug (01100001)+, Thames (01100003)+, Quinnipiac (01100004)+, Housatonic (01100005)+
02 Middle Hudson (02020006)+, Hudson-Wappinger (02020008)+, Raritan (02030105)+, Middle Delaware-Musconetcong (02040105)+*, Crosswicks-Neshaminy (02040201)+, Lower Delaware (02040202)+, Schuylkill (02040203)+*, Cohansey-Maurice (02040206)+, Western Lower Delmarva (02080109)+, Pokomoke-Western Lower Delmarva (02080111)+
03 Lower Roanoke (03010107)+, Ghowan (03010203)+, Meheriin (03010204)+, Lower Tar (03020103)+, Contentnea (03020203)+*, Deep (03030003)+, Lower Cape Fear (03030005)+*, Upper Pee Dee (03040104)+, Lower Pee Dee (03040201)+, Waccamaw (03040206)+
04 Betsy-Chocolay (04020201)+*, St. Joseph (04050001)+*, Lower Grand (04050006)+, Muskegon (04060102)+, Betsie-Platte (04060104)+*, Boardman-Charlevoix (04060105)+, Lone Lake-Ocqueoc (04070003)+*, Cheboygan (04070004)+, Black (04070005)+, Au Sable (04070007)+*, Au Gres-Rifle (04080101)+, Kawkawlin-Pine (04080102)+*, Pigeon-Wiscoggin (04080103)+*, Birch-Willow (04080104)+*, Shiawassee (04080203)+*, Flint (04080204)+*, Cass (04080205)+*, Saginaw (04080206)+*, Lake Huron (04080300)+*, St. Clair (04090001)+*, Lake St. Clair (04090002)+, Clinton (04090003)+*, Detroit (04090004)+, Huron (04090005)+, Ottawa-Stony (04100001)+, Raisin (04100002)+*, Cedar-Portage (04100010)+, Sandusky (04100011)+*, Huron-Vermilion (04100012)+*, Black-Rocky (04110001)+*, Cuyahoga (04110002)+, Chautauqua-Conneaut (04120101)+, Niagara (04120104)+, Lake Erie (04120200)+, Oak Orchard-Twelvemile (04130001)+, Lower Genesee (04130003)+, Irondequoit-Ninemile (04140101)+, Seneca (04140201)+
05 Upper Allegheny (05010001)+, Conewango (05010002)+, French (05010004)+, Shenango (05030102)+
CV CV-26 (CV-26)+*
SU SU-17 (SU-17)+*
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Basic Description: a freshwater mussel
Reproduction Comments: This species is a long-term brooder with fertilization in late summer and glochidial release the following spring. Host fish have not yet been determined. Gravid females were found to display marginal papillae to attract fish hosts for their parasitic larvae. The papillae move rapidly and synchronously attracting fish which attack displaying females causing them to release glochidia onto the fish. Display frequency slows in low light and stops in dark and high turbidity also stops displays (Corey et al., 2006).
Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Riverine Habitat(s): BIG RIVER, Low gradient, MEDIUM RIVER, Pool
Lacustrine Habitat(s): Shallow water
Special Habitat Factors: Benthic
Habitat Comments: This species inhabits protected areas of coastal lakes and ponds, in slackwater areas of rivers, slow moving streams, and in canals in a wide range of substrates (Nedeau et al., 2000). In Canada, it occurs in sheltered areas of lakes, in slack-water areas of rivers and in canals, where it prefers substrates of fine sand and mud at depths ranging from 0.3 to 4.5 m (COSEWIC, 2007).
Economic Attributes Not yet assessed
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Management Summary
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Stewardship Overview: This species was deisignated as endangered in Canada in April 2007 and a status report prepared (COSEWIC, 2007).
Population/Occurrence Delineation
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Group Name: Freshwater Mussels

Use Class: Not applicable
Minimum Criteria for an Occurrence: Occurrences are based on some evidence of historical or current presence of single or multiple specimens, including live specimens or recently dead shells (i.e., soft tissue still attached and/or nacre still glossy and iridescent without signs of external weathering or staining), at a given location with potentially recurring existence. Weathered shells constitute a historic occurrence. Evidence is derived from reliable published observation or collection data; unpublished, though documented (i.e. government or agency reports, web sites, etc.) observation or collection data; or museum specimen information.
Mapping Guidance: Based on the separation distances outlined herein, for freshwater mussels in STANDING WATER (or backwater areas of flowing water such as oxbows and sloughs), all standing water bodies with either (1) greater than 2 km linear distance of unsuitable habitat between (i.e. lotic connections), or (2) more than 10 km of apparently unoccupied though suitable habitat (including lentic shoreline, linear distance across water bodies, and lentic water bodies with proper lotic connections), are considered separate element occurrences. Only the largest standing water bodies (with 20 km linear shoreline or greater) may have greater than one element occurrence within each. Multiple collection or observation locations in one lake, for example, would only constitute multiple occurrences in the largest lakes, and only then if there was some likelihood that unsurveyed areas between collections did not contain the element.

For freshwater mussels in FLOWING WATER conditions, occurrences are separated by a distance of more than 2 stream km of unsuitable habitat, or a distance of more than 10 stream km of apparently unoccupied though suitable habitat. Standing water between occurrences is considered suitable habitat when calculating separation distance for flowing water mussel species unless dispersal barriers (see Separation Barriers) are in place.

Several mussel species in North America occur in both standing and flowing water (see Specs Notes). Calculation of separation distance and determination of separation barriers for these taxa should take into account the environment in which the element was collected. Juvenile mussels do not follow this pattern and juveniles are typically missed by most standard sampling methods (Hastie and Cosgrove, 2002; Neves and Widlak, 1987), therefore juvenile movement is not considered when calculating separation distance.

Separation Barriers: Separation barriers within standing water bodies are based solely on separation distance (see Separation Distance-suitable, below). Separation barriers between standing water bodies and within flowing water systems include lack of lotic connections, natural barriers such as upland habitat, absence of appropriate species specific fish hosts, water depth greater than 10 meters (Cvancara, 1972; Moyle and Bacon, 1969) or anthropogenic barriers to water flow such as dams or other impoundments and high waterfalls.
Separation Distance for Unsuitable Habitat: 2 km
Separation Distance for Suitable Habitat: 10 km
Alternate Separation Procedure: None
Separation Justification: Adult freshwater mussels are largely sedentary spending their entire lives very near to the place where they first successfully settled (Coker et al., 1921; Watters, 1992). Strayer (1999) demonstrated in field trials that mussels in streams occur chiefly in flow refuges, or relatively stable areas that displayed little movement of particles during flood events. Flow refuges conceivably allow relatively immobile mussels to remain in the same general location throughout their entire lives. Movement occurs with the impetus of some stimulus (nearby water disturbance, physical removal from the water such as during collection, exposure conditions during low water, seasonal temperature change or associated diurnal cycles) and during spawning. Movement is confined to either vertical movement burrowing deeper into sediments though rarely completely beneath the surface, or horizontal movement in a distinct path often away from the area of stimulus. Vertical movement is generally seasonal with rapid descent into the sediment in autumn and gradual reappearance at the surface during spring (Amyot and Downing, 1991; 1997). Horizontal movement is generally on the order of a few meters at most and is associated with day length and during times of spawning (Amyot and Downing, 1997). Such locomotion plays little, if any, part in the distribution of freshwater mussels as these limited movements are not dispersal mechanisms. Dispersal patterns are largely speculative but have been attributed to stream size and surface geology (Strayer, 1983; Strayer and Ralley, 1993; van der Schalie, 1938), utilization of flow refuges during flood stages (Strayer, 1999), and patterns of host fish distribution during spawning periods (Haag and Warren, 1998; Watters, 1992). Lee and DeAngelis (1997) modeled the dispersal of freshwater into unoccupied habitats as a traveling wave front with a velocity ranging from 0.87 to 2.47 km/year (depending on mussel life span) with increase in glochidial attachment rate to fish having no effect on wave velocity.

Nearly all mussels require a host or hosts during the parasitic larval portion of their life cycle. Hosts are usually fish, but a few exceptional species utilize amphibians as hosts (Van Snik Gray et al., 2002; Howard, 1915) or may metamorphose without a host (Allen, 1924; Barfield et al., 1998; Lefevre and Curtis, 1911; 1912). Haag and Warren (1998) found that densities of host generalist mussels (using a variety of hosts from many different families) and displaying host specialists (using a small number of hosts usually in the same family but mussel females have behavioral modifications to attract hosts to the gravid female) were independent of the densities of their hosts. Densities of non-displaying host specialist mussels (using a small number of hosts usually in the same family but without host-attracting behavior) were correlated positively with densities of their hosts. Upstream dispersal of host fish for non-displaying host specialist mussels could, theoretically, transport mussel larvae (glochidia) over long distances through unsuitable habitat, but it is unlikely that this occurs very often. D. Strayer (personal communication) suggested a distance of at least 10 km, but a greater distance between occurrences may be necessary to constitute genetic separation of populations. As such, separation distance is based on a set, though arbitrary, distance between two known points of occurrence.

Date: 18Oct2004
Author: Cordeiro, J.
Notes: Contact Jay Cordeiro (jay_cordeiro@natureserve.org) for a complete list of freshwater mussel taxa sorted by flow regime.
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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NatureServe Conservation Status Factors Edition Date: 31Dec2011
NatureServe Conservation Status Factors Author: Cordeiro, J.
Management Information Edition Date: 17Jan2008
Management Information Edition Author: Cordeiro, J.
Element Ecology & Life History Edition Date: 31Dec2011
Element Ecology & Life History Author(s): Cordeiro, J.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
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  • Metcalfe-Smith, J.L., S.K. Staton, G.L. Mackie, and N.M. Lane. 1997. Biodiversity of freshwater mussels in the lower Great Lakes drainage basin. Plenary presentation at the Third National Eman Meeting, Saskatoon, SK.

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  • 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.

  • Smith, J. 1999. Unionid Ranks. Email letter to D.A. Sutherland, dated September 27. 1 pp.

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  • Strayer, D. 1983. The effects of surface geology and stream size on freshwater mussel (Bivalvia, Unionidae) distribution in southeastern Michigan, U.S.A. Freshwater Biology 13:253-264.

  • Strayer, D.L. 1999a. Use of flow refuges by unionid mussels in rivers. Journal of the North American Benthological Society 18(4):468-476.

  • Strayer, D.L. and J. Ralley. 1993. Microhabitat use by an assemblage of stream-dwelling unionaceans (Bivalvia) including two rare species of Alasmidonta. Journal of the North American Benthological Society 12(3):247-258.

  • Strayer, David L. 1987. Ecology and zoogeography of the freshwater mollusks of the Hudson River basin. Malacological Review 20:1-68.

  • 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.

  • Strayer, David L., Kurt J. Jirka, and Kathryn J. Schneider. 1991. Recent collections of freshwater mussels (Bivalvia: Unionidae) from western New York. Walkerana 5(12): 63-72.

  • Strayer, David. 1991. Memo to the Endangered Species Unit of August 19, 1991 regarding the extent and size of the population of the dwarf wedge mussel, Alasmidonta heterodon, in the Lower Neversink River.

  • The Catena Group. 2006. Freshwater mussel surveys of the Pee Dee River basin in South Carolina. Unpublished report prepared for the Nature Conservancy- South Carolina Chapter, January 3, 2006. 47 pp.

  • Turgeon, D.D., J.F. Quinn, Jr., A.E. Bogan, E.V. Coan, F.G. Hochberg, W.G. Lyons, P.M. Mikkelsen, R.J. Neves, C.F.E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F.G. Thompson, M. Vecchione, and J.D. Williams. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland: 526 pp.

  • Van der Schalie, H. 1938a. The naiad fauna of the Huron River in southeastern Michigan. Miscellaneous Publication of the Museum of Zoology, University of Michigan 40:7-78.

  • Watters, G. T. 2018. A preliminary review of the nominal genus Villosa of freshwater mussels (Bivalvia, Unionidae) in North America. Visaya, Supplement (10). 140 pp.

  • Watters, G.T. 1992a. Unionids, fishes, and the species-area curve. Journal of Biogeography 19:481-490.

  • Watters, G.T. 1995a. A field guide to the freshwater mussels of Ohio. revised 3rd edition. Ohio Department of Natural Resources, Division of Wildlife, Columbus, Ohio. 122 pp.

  • Williams, J. D., A. E. Bogan, R. S. Butler, K. S. Cummings, J. T. Garner, J. L. Harris, N. A. Johnson, and G. T. Watters. 2017. A revised list of the freshwater mussels (Mollusca: Bivalvia: Unionida) of the United States and Canada. Freshwater Mollusk Biology and Conservation 20:33-58.

  • Williams, J.D., M.L. Warren, Jr., K.S. Cummings, J.L. Harris, and R.J. Neves. 1993b. Conservation status of freshwater mussels of the United States and Canada. Fisheries 18(9): 6-22.

References for Watershed Distribution Map
  • Bogan, A.E. 1993a. Workshop on freshwater bivalves of Pennsylvania. Workshop hosted by Aquatic Systems Corporation, Pittsburgh, Pennsylvania, held at Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, 6-7 May 1993. 80 pp.

  • Bogan, A.E. and J.M. Alderman. 2004. Workbook and key to the freshwater bivalves of South Carolina. North Carolina Museum of Natural Sciences: Raleigh, North Carolina. 64 pp.

  • Bogan, A.E. and T. Proch. 1995. Manual of the freshwater bivalves of Maryland. Prepared for a workshop held at Versar, Inc., Columbia, Maryland, 9 March 1995. 68 pp.

  • COSEWIC. 2007. COSEWIC assessment and status report on the eastern pondmussel Ligumia nasuta in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, Canada. 34 pp.

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

  • Graf, D.L. 2002. Historical biogeography and late glacial origin of the freshwater pearly mussel (Bivalvia: Unionidae) faunas of Lake Erie, North America. Occasional Papers on Mollusks 6(82):175-211.

  • Metcalfe-Smith, J.L. and B. Cudmore-Vokey. 2004. National general status assessment of freshwater mussels (Unionacea). National Water Research Institute / NWRI Contribution No. 04-027. Environment Canada, March 2004. Paginated separately.

  • Raithel, C.J. and R.H. Hartenstein. 2006. The status of freshwater mussels in Rhode Island. Northeastern Naturalist 13(1):103-116.

  • Schloesser, D.W., J.L. Metcalfe-Smith, W.P. Kovalak, G.D. Longton, and R.D. Smithee. 2006. Extirpation of freshwater mussels (Bivalvia: Unionidae) following the invasion of dreissenid mussels in an interconnecting river of the Laurentian Great Lakes. American Midland Naturalist, 155: 307-320.

  • Smith, D.G. 2000a. Keys to the Freshwater Macroinvertebrates of Southern New England. Douglas G. Smith: Sunderland, Massachusetts. 243 pp.

  • Strayer, D.L. and K.J. Jirka. 1997. The Pearly Mussels of New York State. New York State Museum Memoir 26. The University of the State of New York. 113 pp. + figures.

  • Watters, G.T., M.A. Hoggarth, and D.H. Stansbery. 2009b. The Freshwater Mussels of Ohio. Ohio State University Press: Columbus, Ohio. 421 pp.

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