Utterbackiana suborbiculata - (Say, 1831)
Flat Floater
Synonym(s): Anodonta suborbiculata Say, 1831 ;Utterbackia suborbiculata (Say, 1831)
Taxonomic Status: Accepted
Related ITIS Name(s): Anodonta suborbiculata Say, 1831 (TSN 79945)
Unique Identifier: ELEMENT_GLOBAL.2.114207
Element Code: IMBIV04130
Informal Taxonomy: Animals, Invertebrates - Mollusks - Freshwater Mussels
 
Kingdom Phylum Class Order Family Genus
Animalia Mollusca Bivalvia Unionoida Unionidae Utterbackiana
Genus Size: B - Very small genus (2-5 species)
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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: Anodonta suborbiculata
Taxonomic Comments: Without discussion, Graf and Cummings (2007) and Cummings and Graf (2010) placed Anodonta couperiana, A. heardi, and A. suborbiculata in Utterbackia, and A. implicata in Pyganodon. Because no supporting evidence was provided, Williams et al. (2017) do not recognize these changes. The next available genus for the eastern North American clade (A. couperiana, A. heardi, A. suborbiculata, and A. implicata) identified as distinct by Mock et al. (2004) is Utterbackiana. Anodonta hartfieldorum Williams, Bogan, and Garner, 2009, was described subsequently and also belongs to Utterbackiana (Williams et al. 2017).
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 09Jan2014
Global Status Last Changed: 25Nov1996
Rounded Global Status: G5 - Secure
Reasons: This species has a very large range, and its populations appear to be stable or expanding in most areas of the United States. Threats are minimal.
Nation: United States
National Status: N5 (16Jul1998)

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 Alabama (S3), Arkansas (S4), Georgia (SNA), Illinois (S3), Indiana (S3), Iowa (S3), Kansas (S1), Kentucky (S4S5), Louisiana (S5), Minnesota (S3), Mississippi (S4), Missouri (S2), Nebraska (S1), Ohio (S3), Pennsylvania (S1), South Dakota (S2), Tennessee (S5), Texas (S3), West Virginia (S1), Wisconsin (S2S3)

Other Statuses

American Fisheries Society Status: Currently Stable (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 can be found in the Mississippi River drainage from Nebraska east to Iowa, Illinois, and Ohio, south to Louisiana, as well as in the Mississippi River, Wisconsin; Ohio River drainage in Ohio west to Kansas and South Dakota; and Tennessee River drainage; as well as some Gulf Coast drainages such as the Escambia River system in Alabama and Florida, west to the Brazos River in Texas (Parmalee and Bogan, 1998; Williams et al., 2008). As there were no records from Alabama and Florida including the Mobile Basin prior to 1946, Williams et al. (2008) suggests it has colonized or been introduced since impoundment of the major rivers there.

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

Number of Occurrences: 21 - 300
Number of Occurrences Comments: In Minnesota, it is found in some of the large rivers, backwaters, or sloughs in the Mississippi River below St. Anthony Falls and lower Minnesota River (Sietman, 2003). It can be found in South Dakota from backwater habitats of the Missouri River in the Vermillion area (Backlund, 2000). In Texas, it is known from east Texas from the Brazos River north and east, with the range apparently expanding (Howells et al., 1996). In Kansas, it is known from the Marais des Cygnes and Neosho River basins (Couch, 1997). In Tennessee, it is found in the large lakes and rivers of west and middle part and is often abundant (Parmalee and Bogan, 1998). In Kentucky it is occasional to sporadic from the Mississippi River to the Licking River basins (Cicerello and Schuster, 2003) and Gordon (1991) collected it in the Rough River in Ohio Co. in 1991. McGregor and Garner (2004) found it in the Bear Creek drainage in Alabama/Mississippi. In the Alabama and Mobile basin, it occurs in the Tennessee River drainage, Mobile Basin (recent expansion) and Escambia River drainage (Williams et al., 2008). In Mississippi, it occurs in the Mississippi River North and South, Yazoo, Tennessee, Pearl, Pascagoula, and Tombigbee drainages (Jones et al., 2005). In Louisiana, Vidrine (1993) cites distribution as common in the Atchafalaya Basin at Henderson Swamp, from Edwards Lake, Caddo Lake, Sabine Riverr, Neches River, San Jacinto River, and in lakes in eastern Louisiana in Tangipahoa and Pearl drainages (Brown and Banks, 2001). It occurs in the Middle White (Gordon, 1982), St. Francis (Ahlstedt and Jenkinson, 1991), and Cache River, Arkansas (Christian et al., 2005) as well as throughout the Mississippi Alluvial Valley just below the fall line (Harris and Gordon, 1987). In Illinois, it is occasionally found in floodplain ponds or quiet backwaters of large rivers and can be locally abundant in some ponds in extreme southern Illinois (Cummings and Mayer, 1997; Schanzle and Cummings, 1991). Indiana distribution: Wabash tributaries (Fisher, 2006), Tippecanoe (Cummings and Berlocher, 1990), upper E. Fork White (Harmon, 1992). In Ohio, it has reached the banks of the Ohio River in Clement, Scioto, and Meigs Cos.. Little Miami in Warren Co., Whitewater and Great Miami in Hamilton Co., Muskingum in Washington Co., and Scioto River in Franklin, Pickaway, and Ross Cos. (Watters, 1995; Watters et al., 2009). In Pennsylvania it is rare in the Ohio River drainage only in Beaver Co. (Spoo, 2008). In Florida, it was once known from Chumuckla Springs, Santa Rosa Co., but recent efforts to collect it there were unsuccessful, but it was rediscovered in the Escambia River in Escambia-Rosa Cos. in 1988 (Butler, 1989). In Arkansas, Ahlstedt and Jenkinson (1991) collected 5 specimens from three river sties and 18 specimens from 6 ditch sites in the St. Francis River system, Davidson (1997) found it widespread but uncommon in Ozark Lake and Lake Dardanelle in the Arkansas River Navigation System, and it comprises a minor portion of the community at specific sites in the Ouachita River, Lake Dardanelle, and Lake Chicot (Harris et al., 1997). It has recently expanded its range in northwestern Georgia , near the Georgia/Alabama border (GA NHP, pers. comm., March 2007). In the Coosa River basin in Georgia, it is known from the Coosa River drainage (Williams and Hughes, 1998).

Population Size: >1,000,000 individuals

Number of Occurrences with Good Viability/Integrity: Some to many (13-125)

Short-term Trend: Increase of >10%
Short-term Trend Comments: Sietman (2003) notes this species likely expanded into Minnesota since damming of the Mississippi River. Its range is expanding in the Alabama and Mobile River basins in Alabama and Georgia (Williams et al., 2008).

Long-term Trend: Decline of <30% to increase of 25%

Intrinsic Vulnerability Comments: Freshwater mussels are inherently vulnerable to threats from siltation, pollution, eutrophication, channelization, impoundment, collection, drought and water withdrawal, competiton from invasive non-native mussels, and changes to larval host fish populations.

Other NatureServe Conservation Status Information

Protection Needs: Maintain high water and benthic habitat (substrate) qualities, as well as adequate flow regimes, throughout all occupied river systems. This may be partially accomplished via establishment of buffers and streamside management zones for all agricultural, silvicultural, mining, and developmental activities; protection of floodplain forests and adjoining upland habitat is paramount. Best management practices to follow include employing forestry practices that cause minimal soil erosion; preventing access of livestock to natural surface waters and drains; situating roads at least 0.25 mi. (0.4 km) from heads of all tributaries, even more on steep slopes; using silt fencing and vegetation to control runoff and siltation at all stream crossings, especially during construction and maintenance; using and maintaining sewer systems rather than septic tanks and stream-dumping for management of wastewater; and avoiding use of agricultural pesticides on porous soils near streams. Prevent damming, dredging, and pollution throughout drainages, but especially near recorded sites. Remove existing dams, but with great care to limit downstream sedimentation. Limit withdrawal of surface and subterranean waters as necessary to maintain normal stream flows, especially during drought. Prevent or limit establishment of invasive species (including zebra mussel, Dreissena polymorpha) to the extent possible. Where appropriate, protect populations through acquisitions and easements over streamside lands by working with government agencies and conservation organizations.

Distribution
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Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) This species can be found in the Mississippi River drainage from Nebraska east to Iowa, Illinois, and Ohio, south to Louisiana, as well as in the Mississippi River, Wisconsin; Ohio River drainage in Ohio west to Kansas and South Dakota; and Tennessee River drainage; as well as some Gulf Coast drainages such as the Escambia River system in Alabama and Florida, west to the Brazos River in Texas (Parmalee and Bogan, 1998; Williams et al., 2008). As there were no records from Alabama and Florida including the Mobile Basin prior to 1946, Williams et al. (2008) suggests it has colonized or been introduced since impoundment of the major rivers there.

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: endemic to a single nation

U.S. & Canada State/Province Distribution
United States AL, AR, GAexotic, IA, IL, IN, KS, KY, LA, MN, MO, MS, NE, OH, PA, SD, TN, TX, WI, WV

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
AL Madison (01089)*, Morgan (01103)
IA Muscatine (19139)
KS Allen (20001), Coffey (20031), Linn (20107), Neosho (20133), Woodson (20207)
MN Houston (27055), Winona (27169)
MO Atchison (29005), Butler (29023), Cedar (29039), Chariton (29041), Clark (29045), Dunklin (29069), Franklin (29071), Hickory (29085), Linn (29115), Livingston (29117), Mississippi (29133), New Madrid (29143), Pemiscot (29155), Pike (29163), Scott (29201), Stoddard (29207), Wayne (29223)
MS Bolivar (28011), Lafayette (28071)*, Leflore (28083)*, Monroe (28095), Sharkey (28125), Sunflower (28133), Tishomingo (28141)*, Washington (28151)
NE Burt (31021), Cedar (31027), Dakota (31043)*, Washington (31177)
OH Athens (39009), Clermont (39025), Franklin (39049), Hamilton (39061), Pickaway (39129), Scioto (39145), Warren (39165)
PA Beaver (42007)
SD Clay (46027)
WI Buffalo (55011), Crawford (55023), Grant (55043), Iowa (55049), Jackson (55053), Pepin (55091), Richland (55103), Sauk (55111), St. Croix (55109)
WV Mason (54053)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
03 Upper Tombigbee (03160101)+
05 Upper Ohio (05030101)+, Upper Ohio-Shade (05030202)+, Hocking (05030204)+, Upper Scioto (05060001)+, Little Scioto-Tygarts (05090103)+, Ohio Brush-Whiteoak (05090201)+, Little Miami (05090202)+
06 Wheeler Lake (06030002)+, Pickwick Lake (06030005)+*
07 Lower St. Croix (07030005)+, Buffalo-Whitewater (07040003)+, La Crosse-Pine (07040006)+, Black (07040007)+, Lower Chippewa (07050005)+, Coon-Yellow (07060001)+, Lower Wisconsin (07070005)+, Copperas-Duck (07080101)+, Bear-Wyaconda (07110001)+, Salt (07110007)+, Meramec (07140102)+
08 Lower Mississippi-Memphis (08010100)+, New Madrid-St. Johns (08020201)+, Lower St. Francis (08020203)+, Little River Ditches (08020204)+, Lower Mississippi-Greenville (08030100)+, Little Tallahatchie (08030201)+*, Upper Yazoo (08030206)+*, Big Sunflower (08030207)+, Deer-Steele (08030209)+
10 Lewis and Clark Lake (10170101)+, Vermillion (10170102)+, Blackbird-Soldier (10230001)+, Keg-Weeping Water (10240001)+, Lower Grand (10280103)+, Lower Marais Des Cygnes (10290102)+, Sac (10290106)+, Pomme De Terre (10290107)+
11 Upper Black (11010007)+, Upper Neosho (11070204)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
U.S. Distribution by Watershed (based on multiple information sources) Help
Ecology & Life History
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General Description: See Williams and Butler (in press) for full description.
Diagnostic Characteristics: A large suborbiculate in outline, with a broadly rounded ventral outline. According to Watters (1997) resembles ANODONTA WOODIANA (native to southeaster Asia, but could appear in the U.S.).
Reproduction Comments: Bradytictic (long-term brooder). Separate sexed with spermatozeugmata released in September and glochidia in January to February (Barnhart and Roberts, 1996). Fish hosts include white crappie, warmouth, largemouth bass, golden shiner, mosquitofish. Howells (1997) reported longear sunfish (Lepomismegalotis), green sunfish (Lepomis cyanellus), and channel catfish (Ictalurus punctatus) as hosts.
Ecology Comments: Like cogeners, a backwater species of large river floodplain waters. Tolerant of impoundments.
Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Riverine Habitat(s): BIG RIVER, Low gradient, Pool
Lacustrine Habitat(s): Shallow water
Special Habitat Factors: Benthic
Habitat Comments: In sand or mud substrates in lakes and sloughs (Johnson, 1980) and the sluggish portions of streams. Muddy substrates or reservoirs (Heard, 1979). Medium sized creeks to large river backwaters, as well as in oxbows, sloughs, and impoundments with muddy substrates (Williams and Bulter in prep.). Has also been found in riverine habitat in sand with slow current (Butler, 1989).
Adult Food Habits: Detritivore
Immature Food Habits: Parasitic
Food Comments: Presumably fine particulate organic matter, primarily detritus, and/or zooplankton, and/or phytoplankton (Fuller, 1974). Larvae (glochidia) of freshwater mussels generally are parasitic on fish and there may be a specificity among some species.
Length: 13 centimeters
Economic Attributes Not yet assessed
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Management Summary Not yet assessed
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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: 09Jan2014
NatureServe Conservation Status Factors Author: Jackson, D. R. (2014); Cordeiro, J. (2009)
Element Ecology & Life History Edition Date: 11Dec2007
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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  • Utterback, W. I.  1915.  The naiades of Missouri.  IV.  American Midland Naturalist 4(6):244-273.

  • 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., M. A. Hoggarth, and D. H. Stansbery.  2009.  The freshwater musssels of Ohio.  Second edition.  Ohio State University Press,  Columbus.  421 pp. + xii

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

  • Watters, G.T. 1997. A synthesis and review of the expanding range of the asian freshwater mussel Anodonta woodiana (Lea, 1834) (Bivalvia: Unionidae). The Veliger, 40(2): 152-156.

  • Willams, J. D., A. E. Bogan, and J. T. Garner.  2008.  Freshwater mussels of Alabama and the Mobile Basin in Georgia, Mississippi and Tennessee.  Universiy of Alabama Press, Tuscaloosa.  960 pp.

  • Williams, J. D., A. E. Bogan, and J. T Garner. 2008. Freshwater mussels of Alabama & the Mobile Basin in Georgia, Mississippi, & Tennessee. University of Alabama Press, Tuscaloosa, Alabama. 908 pages.

  • 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. and M.H. Hughes. 1998. Freshwater mussels of selected reaches of the main channel rivers in the Coosa drainage of Georgia. U.S. Geological report to U.S. Army Corps of Engineers, Mobile District, Alabama. 21 pp.

  • Williams, J.D. and R.S. Butler. 1994. Class Bivalvia, Order Unionoida, freshwater bivalves. Pages 53-128, 740-742 in M. Deyrup and R. Frantz (eds.) Rare and Endangered Biota of Florida. Volume 4. Invertebrates. University Press of Florida, Gainesville, Florida. 798 pp.

  • Williams, J.D. and R.S. Butler. Freshwater mussels. Vol. 6, Invertebrates. R Frantz, ed. Rare and endangered biota of Florida. FL Committee on Rare and Endangered Plants and Animals, Univ. Presses of FL. In press.

  • 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.

  • Zanatta, D.T., A. Ngo, and J. Lindell. 2007a. Reassessment of the phylogenetic relationships among Anodonta, Pyganodon, and Utterbackia (Bivalvia: Unionoida) using mutation coding of allozyme data. Proceedings of the Academy of Natural Sciences of Philadelphia 156: 211-216.

  • anonymous. 1996. Neosho River oxbows still hold flat floaters. Kansas Pearly Mussel Newsline, 1: 6.

References for Watershed Distribution Map
  • Brown, K.M. and P.D. Banks. 2001. The conservation of unionid mussels in Louisiana rivers: diversity, assemblage composition and substrate use. Aquatic Conservation: Marine and Freshwater Ecosystems, 11(3): 189-198.

  • Christian, A.D., J.L. Harris, W.R. Posey, J.F. Hockmuth, and G.L. Harp. 2005. Freshwater mussel (Bivalvia: Unionidae) assemblages of the lower Cache River, Arkansas. Southeastern Naturalist, 4(3): 487-512.

  • Cicerello, R.R. and G.A. Schuster. 2003. A guide to the freshwater mussels of Kentucky. Kentucky State Nature Preserves Commission Scientific and Technical Series 7:1-62.

  • Cummings, K.S. and C.A. Mayer. 1997. Distributional checklist and status of Illinois freshwater mussels (Mollusca: Unionacea). Pages 129-145 in: K.S. Cummings, A.C. Buchanan, C.A. Mayer, and T.J. Naimo (eds.) Conservation and management of freshwater mussels II: initiatives for the future. Proceedings of a UMRCC Symposium, October 1995, St. Louis, Missouri. Upper Mississippi River Conservation Committee, Rock Island, Illinois.

  • Gordon, M.E. 1982. Mollusca of the White River, Arkansas and Missouri. The Southwestern Naturalist, 27(3): 347-352.

  • Gordon, M.E. 1991. Aquatic mollusca of the Rough River in the vicinity of the Fort Hartford Mine site, Ohio County, Kentucky. Unpublished final report for Environmental and Safety Designs, Memphis, Tennessee, 6 July 1991. 10 pp.

  • Harmon, J.L. 1992. Naiades (Bivalvia: Unionidae) of Sugar Creek, east fork White River drainage, in central Indiana. Malacology Data Net 3(1-4):31-42.

  • Harris, J.L. and M.E. Gordon. 1987. Distribution and status of rare and endangered mussels (Mollusca: Margaritiferidae, Unionidae) in Arkansas. Proceedings of the Arkansas Academy of Science, 41: 49-56.

  • Howells, R.G., R.W. Neck, and H.D. Murray. 1996. Freshwater Mussels of Texas. Texas Parks and Wildlife Press: Austin, Texas. 218 pp.

  • Jones, R.L., W.T. Slack, and P.D. Hartfield. 2005. The freshwater mussels (Mollusca: Bivalvia: Unionidae) of Mississippi. Southeastern Naturalist, 4(1): 77-92.

  • Mirarchi, R.E., et al. 2004a. Alabama Wildlife. Volume One: A Checklist of Vertebrates and Selected Invertebrates: Aquatic Mollusks, Fishes, Amphibians, Reptiles, Birds, and Mammals. University of Alabama Press: Tuscaloosa, Alabama. 209 pp.

  • Oesch, R.D. 1995. Missouri Naiades. A Guide to the Mussels of Missouri. Second edition. Missouri Department of Conservation: Jefferson City, Missouri. viii + 271 pp.

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

  • Sietman, B.E. 2003. Field Guide to the Freshwater Mussels of Minnesota. Minnesota Department of Natural Resources: St. Paul, Minnesota. 144 pp.

  • Sietman, B.E., S.D. Whitney, D.E. Kelner, K.D. Blodgett, and H.L. Dunn. 2001. Post-extirpation recovery of the freshwater mussel (Bivalvia: Unionidae) fauna in the Upper Illinois River. Journal of Freshwater Ecology, 16(2): 273-281.

  • Spoo, A. 2008. The Pearly Mussels of Pennsylvania. Coachwhip Publications: Landisville, Pennsylvania. 210 pp.

  • Vidrine, M.F. 1993. The Historical Distributions of Freshwater Mussels in Louisiana. Gail Q. Vidrine Collectibles: Eunice, Louisiana. xii + 225 pp. + 20 plates.

  • 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.

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

  • Williams, J.D., A.E. Bogan, and J.T. Garner. 2008. Freshwater Mussels of Alabama & the Mobile Basin in Georgia, Mississippi & Tennessee. University of Alabama Press: Tuscaloosa, Alabama. 908 pp.

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