Strophitus radiatus - (Conrad, 1834)
Rayed Creekshell
Synonym(s): Alasmidonta radiata Conrad, 1834 ;Anodontoides radiatus (Conrad, 1834)
Taxonomic Status: Accepted
Related ITIS Name(s): Anodontoides radiatus (Conrad, 1834) (TSN 80149)
Unique Identifier: ELEMENT_GLOBAL.2.1027704
Element Code: IMBIV42040
Informal Taxonomy: Animals, Invertebrates - Mollusks - Freshwater Mussels
 
Kingdom Phylum Class Order Family Genus
Animalia Mollusca Bivalvia Unionoida Unionidae Strophitus
Genus Size: A - Monotypic genus
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Concept Reference
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Concept Reference: Smith, C. H., N. A. Johnson, J. M. Pfeiffer, and M. M. Gangloff. 2018. Molecular and morphological data reveal non-monophyly and speciation in imperiled freshwater mussels (Anodontoides and Strophitus). Molecular Phylogenetics and Evolution 119:50-62.
Concept Reference Code: A18SMI01EHUS
Name Used in Concept Reference: Strophitus radiatus
Taxonomic Comments: Molecular and morphological evidence supports the inclusion of Anodontoides radiatus in the genus Strophitus, and Smith et al. (2018) resurrect the binomial Strophitus radiatus to reflect their shared common ancestry. Smith et al. (2018) also found evidence for as many as 4 evolutionary divergent clades within S. radiatus and have described two additional species from the S. radiatus species complex (Strophitus williamsi and Strophitus pascagoulaensis) and recognize the potential for a third putative species (Strophitus sp. cf. pascagoulaensis).
Conservation Status
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NatureServe Status

Global Status: G2G3
Global Status Last Reviewed: 06Mar2018
Global Status Last Changed: 06Mar2018
Ranking Methodology Used: Ranked by calculator
Rounded Global Status: G2 - Imperiled
Reasons: The rayed creekshell was historically rare in large parts of its range, and recent surveys suggest further reductions in both the number of sites where it occurs as well as the number of individuals found per occurrence, although the decline in extent of occurrence is likely not above 30%. The reasons for its decline are unknown. Despite this decline, some new sites have been uncovered (about a dozen) recently in Alabama as well as one in Florida where it was formerly thought extirpated, and the species can still be found in all the southeastern states.
Nation: United States
National Status: N2N3 (06Mar2018)

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), Florida (S2), Georgia (S2), Mississippi (S2)

Other Statuses

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

NatureServe Global Conservation Status Factors

Range Extent: 5000-20,000 square km (about 2000-8000 square miles)
Range Extent Comments: This species is endemic to the Mobile and Apalachicola drainages, and the Yazoo River of the Mississippi drainage. According to the map in Smith et al. (2018), the occurrence in Louisiana is not confirmed (?unknown?). It is possible that accounts of S. radiatus in tributaries of the lower Mississippi and Big Black rivers may represent S. undulatus; additional sampling of S. undulatus and S. radiatus in the lower Mississippi River drainage is necessary to determine whether S. radiatus does indeed occur in the southern Mississippi and Big Black rivers or if accounts are based on misidentified S. undulatus specimens (Smith et al. 2018).

Area of Occupancy: 2,501 to >12,500 4-km2 grid cells
Area of Occupancy Comments: Linear occupancy is unknown.

Number of Occurrences: 6 - 80
Number of Occurrences Comments: The range of this species covers portions of at least 4 of the southeastern-most states (Florida, Georgia, Alabama and Mississippi); the occurrence in Louisiana is not confirmed (?unknown?).

Further details (needs updating based on Smith et al. 2018): Historical occurrences cited by Johnson (1967) include the following: Conecuh River drainage, Alabama; Chattahoochee and Flint River drainages, west/southeast Georgia; Apalachicola River drainage, Florida; Chipola River drainage, Florida; Coosa River drainage, Alabama [note: likely only in the Lower Tallapoosa; upper Coosa occurrences are likely Strophitus connasaugaensis]. In the Apalachicola-Chattahoochee-Flint (ACF) Basin, this species was historically known from 21 occurrences, but in a recent survey it was found at only four of 324 sites surveyed (Brim Box and Williams, 2000). Brim Box and Williams (2000) also cite (mistakenly as Strophitus subvexus) 20 historical collections from 16 sites in the ACF Basin (Alabama, Florida, and Georgia), and in a recent survey was not collected at any of the historical occurrences but was found at nine new sites (of 324 surveyed) in Alabama and Georgia. It appears to be extirpated from all 10 historical sites in the Chipola River system. It was known historically from two sites in the Pea River system (Choctawhatchee River tributary), and in a recent survey of 50 sites was not collected at either historical site but was found at five new ones in tributary streams (Blalock et al., 1998- as S. subvexus). In the Escambia River system, it was known from one occurrence from Patsaliga Creek (Conecuh River tributary), and in a recent survey it was located at two new sites in the Sepulga River drainage, but not at the historical locality in Patsaliga Creek (Williams et al., 2000- as S. subvexus). There are no known historical or recent occurrences in the Yellow River drainage, although 179 sites were recently surveyed in the Escambia and Yellow drainages. In 1999 and 2001, this species was found in 10 sites (10 specimens) and 9 sites (5 specimens), respectively, in surveys of 5 sites (each year) in about a dozen tributary streams of the lower Flint River Basin, southwestern Georgia (Golladay et al., 2004). Blalock-Herod et al. (2005) confirm the distribution gap in the Choctawhatchee River drainage based on historical literature but did find 12 new sites (11 in Alabama, 1 in Florida) there during recent survey efforts (mostly small tributaries). Recent historical data reports exist for the Choctawhatchee River drainage in Alabama/Florida, but Pilarczyk et al. (2006) surveyed 24 sites in 2004 and did not find this species. In the Coosa River basin in Georgia, it is known historically from the Etowah and Oostanaula River drainages but has not been collected live recently (Williams and Hughes, 2001). Vidrine (1993) cited Louisiana distribution as western Louisiana as well as the Taucipano River in eastern Louisiana, among other scattered locations. Brown and Banks (2001) list 1990s eastern Louisiana records for the Amite and Tangipahoa Rivers. In the Alabama and Mobile basin, it is widespread in the Mobile Basin below the Fall Line, with a few records from above; east of Mobile Basin, it is found in the Escambia Choctawhatchee, Chipola, and Chattahoochee River drainages. (Williams et al., 2008).

Population Size: 1000 - 1,000,000 individuals
Population Size Comments: There is little known about the historical abundance of this species. Museum records suggest that historically it was seldom collected in large numbers, and today it is unusual to find more than a few individuals at a site. Clench and Turner (1956) noted that Anodontoides radiatus was "exceedingly rare" in the ACF Basin. Heard (1975) listed A. radiatus among species he considered to have a reduced range or abundance (i.e., are now very rare or extinct in part of their present or past range, respectively). One of the largest collections of A. radiatus was made by H. H. Smith on 25 June 1915 in Uchee Creek (Russell County, Alabama). The collection totaled 24 individuals (Brim Box and Williams, 2000). In a survey of the Escambia River drainage, 15 live individuals were collected from six sites in upper tributaries (Williams et al., 2000), while a single live individual was found in the Pea River watershed (Blalock et al., 1998).

Number of Occurrences with Good Viability/Integrity: Very few to few (1-12)

Overall Threat Impact Comments: Sedimentation as a result of bank destabilization, runoff from agricultural areas, and pollutants (point and non-point source) are major threats. Overall stream modifications also threaten survival of this species.

Short-term Trend: Decline of 10-30%
Short-term Trend Comments: Surveys of the ACF basin of Alabama, Florida and Georgia revealed no specimens in the Chipola River drainage despite historical records from 10 localities (Brim Box and Williams, 2000; listed mistakenly as Strophitus subvexus). The species is also threatened in the Escambia River system (Williams et al., 2000). Historic and current records indicate it was never collected in large numbers and its occurrence was sporadic throughout its current range. Clench and Turner (1956) noted that it was "exceedingly rare" in the ACF Basin. Heard (1975) listed this species among species he considered to have a reduced range or abundance (i.e., are now very rare or extinct in part of their present or past range, respectively). Williams et al. (1993) considered the rayed creekshell to be of special concern throughout its range, indicating that it should be carefully monitored. It may be nearly extirpated in Florida (formerly in Mosquito Creek, Apalachicola River basin, see Clench and Turner, 1956). Based on the results of a recent survey, it was assigned a conservation status of endangered in the ACF Basin (Brim Box and Williams, 2000). Williams et al. (2000) considered the rayed creekshell to be threatened in the Escambia River drainage. Pilarczyk et al. (2006) did not find any specimens in a survey of 24 sites of the Choctawhatchee, Yellow, and Conecuh-Escambia River drainages of Alabama in 2004.

Long-term Trend: Decline of <50% to increase of <25%

Intrinsic Vulnerability: Moderately vulnerable
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.

Environmental Specificity: Moderate. Generalist or community with some key requirements scarce.

Other NatureServe Conservation Status Information

Inventory Needs: Additional surveys are needed in the Tombigbee-Alabama river system.

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: (5000-20,000 square km (about 2000-8000 square miles)) This species is endemic to the Mobile and Apalachicola drainages, and the Yazoo River of the Mississippi drainage. According to the map in Smith et al. (2018), the occurrence in Louisiana is not confirmed (?unknown?). It is possible that accounts of S. radiatus in tributaries of the lower Mississippi and Big Black rivers may represent S. undulatus; additional sampling of S. undulatus and S. radiatus in the lower Mississippi River drainage is necessary to determine whether S. radiatus does indeed occur in the southern Mississippi and Big Black rivers or if accounts are based on misidentified S. undulatus specimens (Smith et al. 2018).

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, FL, GA, MS

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
AL Barbour (01005), Bullock (01011), Butler (01013), Coffee (01031), Conecuh (01035), Dale (01045), Dallas (01047), Geneva (01061), Marion (01093), Perry (01105)*, Pike (01109)*, Sumter (01119), Tuscaloosa (01125)*, Wilcox (01131)*
FL Gadsden (12039)*
GA Baker (13007), Calhoun (13037), Coweta (13077), Decatur (13087), Early (13099), Fayette (13113), Lee (13177), Macon (13193), Marion (13197), Meriwether (13199), Miller (13201), Muscogee (13215)*, Pike (13231), Randolph (13243), Schley (13249), Spalding (13255), Sumter (13261)*, Terrell (13273), Upson (13293), Webster (13307)
MS Amite (28005), Benton (28009), Chickasaw (28017)*, Choctaw (28019), Clarke (28023), Copiah (28029), Covington (28031), DeSoto (28033), Hinds (28049), Itawamba (28057), Jefferson Davis (28065)*, Kemper (28069), Lafayette (28071), Lauderdale (28075), Leake (28079), Lincoln (28085), Monroe (28095), Oktibbeha (28105), Perry (28111), Pike (28113), Rankin (28121), Union (28145), Walthall (28147), Webster (28155), Winston (28159)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
03 Middle Chattahoochee-Walter F. George Reservoir (03130003)+*, Lower Chattahoochee (03130004)+, Upper Flint (03130005)+, Middle Flint (03130006)+, Kinchafoonee-Muckalee (03130007)+, Lower Flint (03130008)+, Ichawaynochaway (03130009)+, Spring (03130010)+, Apalachicola (03130011)+*, Upper Choctawhatchee (03140201)+, Pea (03140202)+, Upper Conecuh (03140301)+*, Sepulga (03140303)+, Cahaba (03150202)+, Middle Alabama (03150203)+*, Upper Tombigbee (03160101)+, Buttahatchee (03160103)+, Tibbee (03160104)+*, Noxubee (03160108)+, Lower Black Warrior (03160113)+*, Sucarnoochee (03160202)+, Chunky-Okatibbee (03170001)+, Upper Chickasawhay (03170002)+, Upper Leaf (03170004)+, Lower Leaf (03170005)+, Upper Pearl (03180001)+, Middle Pearl-Strong (03180002)+, Bogue Chitto (03180005)+
08 Little Tallahatchie (08030201)+, Yocona (08030203)+, Coldwater (08030204)+, Yalobusha (08030205)+, Upper Big Black (08060201)+, Bayou Pierre (08060203)+, Amite (08070202)+, Tickfaw (08070203)+, Tangipahoa (08070205)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Basic Description: A medium-sized, elliptical freshwater mussel
General Description: See Deyrup and Franz (1994) for a complete description.
Diagnostic Characteristics: Elliptical outline, slightly raised umbones, and long, low, pseudocardinals, and no lateral teeth.
Reproduction Comments: Glochidia occupy the entire outer gill (Lea, 1863). This species is probably bradytictic (long-term brooder) as is its cogener Anodontoides ferussacianus. The glochidial host is not known.
Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Mobility and Migration Comments: Mobility potential probably good considering affinity for soft substrates. Greatest potential during glochidial stage on fish.
Riverine Habitat(s): BIG RIVER, CREEK, Low gradient, Moderate gradient, Pool, Riffle
Special Habitat Factors: Benthic
Habitat Comments: Although the rayed creekshell is known from large rivers, most collections are from small to medium-sized creeks where it occurs in mud, sand, or gravel substrates in slow to medium currents (Clench and Turner, 1956; Jenkinson, 1973; Heard, 1979).
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.
Phenology Comments: Anodontoides ferussacianus has been found to live 3 to 16 years (average 9 years) in a Michigan stream (Harrigan et al., 2009).
Length: 7.5 centimeters
Economic Attributes Not yet assessed
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Management Summary
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Biological Research Needs: Determine host fish(es), genetic studies to determine how this species (and genus) is distinct from Strophitus spp., continue field surveys to monitor current populations in the ACF, Escambia, and Pea River systems.
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); Brim Box, J., and C. O'Brien (2000), minor revisions by Jackson, D. R. and Sears, N. A. (2018)
Element Ecology & Life History Edition Date: 27Sep2006
Element Ecology & Life History Author(s): Cordeiro, J. (2006); BUTLER, R.S. (2000)

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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  • Blalock-Herod, H. N., J. J. Herod, J. D. Williams, B. N. Wilson, and S. W. McGregor. 2005. A historical and current perspective of the freshwater mussel fauna (Bivalvia: Unionidae) from the Choctawhatchee River drainage in Alabama and Florida. Bulletin of the Alabama Museum of Natural History 24:1-26.

  • Clench, W.J. and R.D. Turner. 1956. Freshwater mollusks of Alabama, Georgia, and Florida from the Escambia to the Suwanee River. Bulletin of the Florida State Museum Biological Sciences, 1(3): 97-239.

  • Deyrup, M. and R. Franz. 1994. Rare and Endangered Biota of Florida, Volume IV. Invertebrates. University Press of Florida: Gainesville, Florida. 798 pp.

  • Deyrup, M., and R. Franz. 1994. Rare and Endangered Biota of Florida, Volume IV: Invertebrates. University Press of Florida, Gainesville, Florida. 798 pp.

  • Deyrup, M., and R. Franz. 1994. Rare and Endangered Biota of Florida, Volume IV: Invertebrates. University Press of Florida, Gainesville. 798 pp.

  • Florida Museum of Natural History. Invertebrate Zoology Master Database. Online. Available: http://www.flmnh.ufl.edu/scripts/dbs/malacol_pub.asp

  • Fuller, S.L.H. 1974. Chapter 8: Clams and mussels (Mollusca: Bivalvia). Pages 215-273 in: C.W. Hart, Jr. and S.L.H. Fuller (eds.) Pollution Ecology of Freshwater Invertebrates. Academic Press: New York. 389 pp.

  • Haag, W.R., M.L. Warren, Jr., K. Wright, and L. Shaffer. 2002. Occurrence of the rayed creekshell, Anodontoides radiatus, in the Mississippi River basin: implications for conservation and biogeography. Southeastern Naturalist, 1(2): 169-178.

  • Harrigan, K., A. Moerke, and P. Badra. 2009. Freshwater mussel (Unionidae) distribution and demographics in relation to microhabitat in a first-order Michigan stream. Michigan Academician 39(3):149-161.

  • Heard, W.H. 1975. Determination of the endangered status of freshwater clams of the Gulf and Southeastern states. Report for the Office of Endangered Species, Bureau of Fisheries and Wildlife, U.S. Department of the Interior. Washington, D.C. 31 pp.

  • Heard, W.H. 1979. Identification manual of the fresh water clams of Florida. State of Florida, Department of Environmental Regulation, Technical Series, 4(2): 1-82.

  • Jenkinson, J.J. 1973. Distribution and zoogeography of the Unionidae (Mollusca: Bivalvia) in four creek systems in east-central Alabama. Unpublished Master's thesis, Auburn University, Auburn, Alabama. 96 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.

  • Pursifull, S. 2013. Collection data for two petitioned bivalves, Anodontoides radiatus and Elliptio arctata. E-mail and excel file sent to D. R. Jackson, 3 September 2013.

  • Smith, C. H., N. A. Johnson, J. M. Pfeiffer, and M. M. Gangloff. 2018. Molecular and morphological data reveal non-monophyly and speciation in imperiled freshwater mussels (Anodontoides and Strophitus). Molecular Phylogenetics and Evolution 119:50-62.

  • Smith, Chase, Nathan Johnson, John Pfeiffer and Michael Gangloff. 2018. Molecular and morphological data reveal non-monophyly and speciation in imperiled freshwater mussels (Anodontoides and Strophitus). Molecular Phylogenetics and Evolution 119(2018) 50-62
     

  • 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.

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

  • 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, and J. T. Garner. 2008. Freshwater Mussels of Alabama and the Mobile Basin in Georgia, Mississippi and Tennessee. University of Alabama Press, Tuscaloosa, Alabama. 908 pp.

  • Williams, J. D., R. S. Butler, G. L. Warren, and N. A. Johnson.  2014.  Freshwater Mussels of Florida.  University of Alabama Press, Tuscaloosa.  498 pp.

  • Williams, J. D., R. S. Butler, G. L. Warren, and N. A. Johnson.  2014a.  Freshwater Mussels of Florida.  University of Alabama Press, Tuscaloosa, Alabama. 498 pp.

  • 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, University Press of Florida, Gainesville.

  • 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.

  • van der Schalie, H. 1940. The naiad fauna of the Chipola River in northwestern Florida. Lloydia 3(3):191-208.

References for Watershed Distribution Map
  • Biological Resources Division, USGS. 1997. Database of museum records of aquatic species. Compiled by J. Williams (USGS-BRD, Gainesville, FL).

  • Blalock, H.N., J.J. Herod, and J.D. Williams. 1998. Freshwater mussels (Unionacea: Bivalvia) of the Pea River Watershed of Alabama and Florida. Final Report for the U.S. Fish and Wildlife Service, Jacksonville, Florida. 61 pp.

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