Villosa trabalis - (Conrad, 1834)
Cumberland Bean
Other English Common Names: Cumberland Bean Pearly Mussel, Purple Bean
Taxonomic Status: Accepted
Related ITIS Name(s): Villosa trabalis (Conrad, 1834) (TSN 80212)
Unique Identifier: ELEMENT_GLOBAL.2.109794
Element Code: IMBIV47140
Informal Taxonomy: Animals, Invertebrates - Mollusks - Freshwater Mussels
Image 12010

Public Domain

 
Kingdom Phylum Class Order Family Genus
Animalia Mollusca Bivalvia Unionoida Unionidae Villosa
Genus Size: C - Small genus (6-20 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: Villosa trabalis
Taxonomic Comments: Taxonomy of the genus Villosa is uncertain. Villosa trabalis and Villosa perpurpurea are very similar. They are both treated as the same species by (Bogan and Parmalee, 1983). Both are regarded as good species by the American Fisheries Society list (Turgeon et al, 1998). Their relationship to each other and the genus Villosa remains unclear (Bogan and Parmalee, 1983). Simpson (1914) and Ortmann (1915) considered Villosa perpurpurea and Villosa trabalis to represent distinct species. However, Ortmann (1918) expressed doubts concerning their separation and later considered them to be varieties of the same species ("Micromya" trabalis in Ortmann, 1925). Recently, Hoggarth (1988) demonstrated that the glochidia of V. perpurpurea and V. trabalis are shaped differently, indicating that the two taxa are separate species. Revision of the genus Villosa may indicate that neither of these two species are actually members of that genus.
Conservation Status
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NatureServe Status

Global Status: G1
Global Status Last Reviewed: 15Feb2011
Global Status Last Changed: 12Mar1998
Rounded Global Status: G1 - Critically Imperiled
Reasons: Once found throughout the Cumberlandian region, it is now restricted to four rivers and has become extirpated from a significant portion of its range to where only a few disjunct occurrences remain, some with questionable viability.
Nation: United States
National Status: N1 (12Mar1998)

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 (SX), Georgia (SH), Kentucky (S1), North Carolina (SH), Tennessee (S1), Virginia (SX)

Other Statuses

U.S. Endangered Species Act (USESA): LE, XN: Listed endangered, nonessential experimental population (14Jun1976)
Comments on USESA: Listed Endangered throughout its range, except in the free-flowing reach of the Tennessee River from the base of Wilson Dam downstream to the backwaters of Pickwick Reservoir and the lower 5 RM of all tributaries to this reach in Colbert and Lauderdale Counties, Alabama. Here it is listed as an experimental, non-essential population. (Federal Register, 14 June 2001).

The USFWS, in cooperation with the State of Tennessee and Conservation Fisheries, Inc., announced a final rule to reintroduce this species into its historical habitat in the free-flowing reach of the French Broad River below Douglas Dam to its confluence with the Holston River, Knox County Tennessee, and in the free-flowing reach of the Holston River below Cherokee Dam to its confluence with the French Broad River (Federal Register, 12 September 2007). The proposed rule for this action was published on June 13, 2006.

U.S. Fish & Wildlife Service Lead Region: R4 - Southeast
IUCN Red List Category: CR - Critically endangered
Convention on International Trade in Endangered Species Protection Status (CITES): Appendix I
American Fisheries Society Status: Endangered (01Jan1993)

NatureServe Global Conservation Status Factors

Range Extent: 250-1000 square km (about 100-400 square miles)
Range Extent Comments: The range of Villosa trabalis is difficult to determine due to confusion in literature with the related species, Villosa perpurpurea. The type locality is listed as streams of Tennessee; Clinch River, Virginia (Simpson, 1914). The historic range of the species is restricted to the lower and upper tributary streams of the Tennessee River and the upper tributary streams of the Cumberland River including the Clinch River, Scott county, Virginia; Hiwassee River, Polk County, Tennessee; South Chickamauga Creek, Catoosa County, Georgia; the Paint Rock River, Jackson County, the Flint River, Madison County, and the Tennessee River at Muscle Shoals, Lauderdale County, all in Alabama. In the upper Cumberland River drainage it is known from the Cumberland River from Pulaski County to Cumberland Falls, Whitley County, Kentucky (Cicerello and Schuster, 2003). It is known from Rockcastle River and its tributary Laurel Fork, Jackson, Rockcastle, and Laurel Counties, Kentucky; also Little South Fork of the Cumberland River, Wayne County, Kentucky and the lower Obey River, Clay County, Tennessee (Bogan and Parmalee, 1983; USFWS, 1984). Its current range includes the Hiwasee River, Polk County, Tennessee and North Carolina; the lower Obey River, Clay County, Tennessee; Rockcastle River and its tributary Laurel Fork in Jackson, Rockcastle, and Laurel Counties and the Little South Fork of the Cumberland River, Wayne County, all in Kentucky (Bogan and Parmalee, 1983). It has been extirpated from Virginia, Alabama, and the mainstem of the Cumberland River in Kentucky (Mirarchi et al., 2004)

Area of Occupancy: 126-2,500 4-km2 grid cells
Area of Occupancy Comments:  

Number of Occurrences: 1 - 5
Number of Occurrences Comments: Less than ten occurrences exist in Kentucky (R. Cicerello, KY NHP, pers. comm., 1998) including Little South Fork Cumberland River (USFWS, 1984) (although this population may be extirpated due to coal-related spills and water quality changes in the 1980s- see USFWS, 2010), mainstem Buck Creek, Rockcastle River, and a new population in 1992 in Sinking Creek (Rockcastle River tributary) (USFWS, 2010) as first reported by Clarke (1983); one in North Carolina (H. LeGrand, NC NHP, pers. comm., 2000; although Bogan, 2002, cited it as extirpated in the state) in Cherokee Co. (LeGrand et al., 2006); and probably fewer than five in Tennessee localized and very restricted in the Hiwassee River in Polk Co., possibly Beech Creek in Hawkins Co. and the Obed River in Cumberland Co., and possibly Coytee Springs on the Little Tennessee River in Loudon Co. (collected prior to impoundment) although this area is now impounded (Parmalee and Bogan, 1998). It was recently reported by Johnson et al. (2005) from the Hiwassee River inside and adjacent to Cherokee National Forest, Polk Co., Tennessee. Clarke (1983) listed occurrences in the Cumberland River just below Cumberland Falls, Buck Creek, Rockcastle River, and Little South Fork Cumberland River in Kentucky. Occasionally a fresh dead individual has been observed in Little Chucky Creek, a tributary of the Nolichucky River in the French Broad River system, Tennessee; but it is not considered viable (USFWS, 2010).

Population Size: 1000 - 2500 individuals
Population Size Comments: Population size estimates are unknown. Records are sporadic in the upper Cumberland drainage, yet is fairly common there and in the Hiwassee River, Polk County, Tennessee. According to Ron Cicerello (KY NHP, pers. comm.) it is hard to find in any numbers in Kentucky. A total of 49 live individuals were reported from 7 sites in the Big South Fork Cumberland River system in Kentucky and Tennessee (USFWS, 2010). 111 live and 3 fresh dead specimens were collected in 2002 in 3 sites of the free-flowing Hiwassee River, with 2 live in 2003 from 2 sites, 3 live and 1 fresh dead from 6 sites in 2005

Number of Occurrences with Good Viability/Integrity: Very few (1-3)
Viability/Integrity Comments: The only viable population in Tennessee, if any, is the Hiwassee River in Polk Co. (Parmalee and Bogan, 1998) and is the best population in Tennessee (USFWS, 2010). The species is most viable in the Cumberland System (USFWS, 1984) with Sinking Creek (Rockcastle River tributary), Kentucky, having the best population (USFWS, 2010).

Overall Threat Impact: Very high - high
Overall Threat Impact Comments: Reasons for decline include imoundment (for flood control, navigation, hydroelectric power production, and recreation), siltation (due to strip mining, coal washing, dredging, farming, logging, and road construction), and pollution (municipal, agricultural, and industrial waste discharges; such as coal mine acids, gravel dredging, fertilizers, pesticides, industrial spills) (USFWS, 1984). At the present time, there are no noticeable improvements in coal-related problems and substrate quality in the upper Cumberland and Tennessee River drainages supporting the species (USFWS, 2010).
From USFWS (2010):
Acid mine wastes and resulting impacts to water quality are either known and/or suspected causes in streams like the Little South Fork, Big South Fork, and Rockcastle River drainages. Threats from transportation corridors, coal mines, and oil and gas wells were still considered dominant threats to Big South Fork populations as recently as 2005. In-stream gravel mining and nonpoint source pollution to water quality and habitat are considered impacts in Buck Creek. In the Hiwassee River, the only known population of V. trabalis exists in an unimpounded section of the river downstream of Apalachia Dam. Minimum flow concerns for this species have resulted in the Tennessee Valley Authority's 2005 decision to provide a minimum flow of 25 cubic feet per second (cfs) in the Hiwassee River downstream of Apalachia Dam from May to October. Other natural or manmade factors affect this mussel. Natural droughts, as well as water withdrawals for human use, can impact water levels. Changes in land use in the recharge area can accelerate pollutants delivery. Other potential threats include contaminant spills, mining (e.g. coal, oil, gas, gravel), siltation from land use practices, and stream impoundments. A portion of the headwaters of Sinking Creek are impacted from development.

Short-term Trend: Decline of >70%
Short-term Trend Comments: The population in Buck Creek, Kentucky, is reproducing but recruitment is very low and population size is small and host fish availability is also limiting. Populations in the Rockcastle River drainage, Kentucky, are viable with Sinking Creek being the most viable. It is relatively rare on the Big South Fork in Virginia and Kentucky known from 7 sites with low recruitment and limited host fish availability. A population in the Hiwassee River, Tennessee, is actively recruiting and viable (USFWS, 2010). Occasionally a fresh dead individual has been observed in Little Chucky Creek, a tributary of the Nolichucky River in the French Broad River system, Tennessee; but it is not considered viable (USFWS, 2010).

Long-term Trend: Decline of 70-90%
Long-term Trend Comments: This species has experienced a huge reduction in range. Lack of recent record in literature make it impossible to determine current trends. Historically, it spanned more than 100 miles of the Cumberland River, at least from near Burkesville (Cumberland Co.), Kentucky upstream to Cumberland Falls (McCreary/Whitley Cos.) including major tributaries from the Obey River in Tennessee to the Rockcastle River in Kentucky before the Cumberland River was impounded (Clarke, 1983). Parmalee and Bogan (1998) also noted occurrences historically in the Clinch River above Norris Lake and the lower Obey River in Clay Co., Tennessee. The species is now extirpated from Alabama, Georgia, and Virginia and the main channel of the Tennessee River upstream from Muscle Shoals, Alabama, and streams of the Tennessee River drainage in Tennessee and Virginia (Parmalee and Bogan, 1998). The most recent Alabama record was from Hurricane Creek, tributary to the Paint Rock River in Jackson Co., in 1980 (Williams et al., 2008).

Intrinsic Vulnerability: Highly vulnerable
Intrinsic Vulnerability Comments: Further loss of habitat could extirpate this species from entire drainages, lending itself toward extinction.

Environmental Specificity: Narrow. Specialist or community with key requirements common.
Environmental Specificity Comments: This species is limited to clean, fast flowing rivers in riffle areas only on gravel and sand substrates. Ideal habitat conditions are hard to find as much of the historical habitata has been degraded and may be incapable of harboring the species (USFWS, 2010).

Other NatureServe Conservation Status Information

Inventory Needs: Determine status and viability of known populations in Sinking Creek, Hiwassee River, Big South Fork of the Cumberland River, Little Chucky Creek, Rockcastle River, and Buck Creek.
Reestablish viable populations in other streams within the historical range that have suitable habitat and water quality conditions, including the upper Clinch River in Tennessee and the Nolichucky, Paint Rock and Elk in Alabama. Conduct surveys on Rockcastle River, Barren Fork, Rocky River, and Falling Water River (tributaries to Caney Fork), West Harpeth and Jones Creek (tributaries to the Harpeth River in Tennessee), North and South Prongs Clear Fork and Brimstone Creek (tributaries to the Big South Fork Cumberland River), Obey River (West and East Forks) and Spring Creek (tributaries to the Cumberland River), and in the lower Hiwassee River downstream of the TVA Powerhouse in the Tennessee River system. The population in the mainstem of the Rockcastle River needs to be surveyed to determine its status.

Protection Needs: Augment and expand extant populations through propagation of juveniles. Determine the degree of threat (e.g., coal mining, oil and gas drilling and water withdrawals, etc.) to each stream in which this species occurs. This could include assessments and/or a threats analysis using GIS. Evaluate TVA's minimum flow of 25 cubic feet per second downstream of the Hiwassee River to determine it the best appropriate flow regime to benefit V. trabalis.

Distribution
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Global Range: (250-1000 square km (about 100-400 square miles)) The range of Villosa trabalis is difficult to determine due to confusion in literature with the related species, Villosa perpurpurea. The type locality is listed as streams of Tennessee; Clinch River, Virginia (Simpson, 1914). The historic range of the species is restricted to the lower and upper tributary streams of the Tennessee River and the upper tributary streams of the Cumberland River including the Clinch River, Scott county, Virginia; Hiwassee River, Polk County, Tennessee; South Chickamauga Creek, Catoosa County, Georgia; the Paint Rock River, Jackson County, the Flint River, Madison County, and the Tennessee River at Muscle Shoals, Lauderdale County, all in Alabama. In the upper Cumberland River drainage it is known from the Cumberland River from Pulaski County to Cumberland Falls, Whitley County, Kentucky (Cicerello and Schuster, 2003). It is known from Rockcastle River and its tributary Laurel Fork, Jackson, Rockcastle, and Laurel Counties, Kentucky; also Little South Fork of the Cumberland River, Wayne County, Kentucky and the lower Obey River, Clay County, Tennessee (Bogan and Parmalee, 1983; USFWS, 1984). Its current range includes the Hiwasee River, Polk County, Tennessee and North Carolina; the lower Obey River, Clay County, Tennessee; Rockcastle River and its tributary Laurel Fork in Jackson, Rockcastle, and Laurel Counties and the Little South Fork of the Cumberland River, Wayne County, all in Kentucky (Bogan and Parmalee, 1983). It has been extirpated from Virginia, Alabama, and the mainstem of the Cumberland River in Kentucky (Mirarchi et al., 2004)

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 ALextirpated, GA, KY, NC, TN, VAextirpated

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
AL Jackson (01071)*, Morgan (01103)*
GA Catoosa (13047)*
KY Clinton (21053)*, Cumberland (21057)*, Jackson (21109), Laurel (21125), Lincoln (21137), McCreary (21147), Pulaski (21199), Rockcastle (21203), Russell (21207)*, Wayne (21231)*, Whitley (21235)*
NC Cherokee (37039)
TN Clay (47027)*, Cumberland (47035), DeKalb (47041)*, Greene (47059), Hawkins (47073), Morgan (47129), Pickett (47137)*, Polk (47139), Putnam (47141)*, Scott (47151), Smith (47159)*
VA Russell (51167)*, Scott (51169)*, Tazewell (51185)*
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
05 Upper Cumberland (05130101)+, Rockcastle (05130102)+, Upper Cumberland-Lake Cumberland (05130103)+, South Fork Cumberland (05130104)+, Obey (05130105)+*, Upper Cumberland-Cordell Hull (05130106)*, Caney (05130108)+*, Lower Cumberland (05130205)*
06 North Fork Holston (06010101)+*, Holston (06010104)+, Pigeon (06010106)*, Lower French Broad (06010107), Nolichucky (06010108)+, Upper Clinch (06010205)+*, Emory (06010208)+, Middle Tennessee-Chickamauga (06020001)+*, Hiwassee (06020002)+, Guntersville Lake (06030001)*, Wheeler Lake (06030002)+*, Pickwick Lake (06030005)*
+ 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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Basic Description: A medium-size freshwater mussel or bivalve mollusk with a dingy olive-green shell with numerous faint wavy green lines.
Reproduction Comments: The glochidial host has only recently been determined. The banded sculpin, Cottus carolinae, striped darter, Etheostoma virgatum, fantail darter, E. flabellare, greenside darter, E. blennioides, and redline darter, E. rufilineatum, could all serve as hosts for this species (Guyot, 2005).
Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Riverine Habitat(s): BIG RIVER, CREEK, High gradient, MEDIUM RIVER, Moderate gradient, Riffle
Special Habitat Factors: Benthic
Habitat Comments: This species is found in sand, gravel, and cobble substrates in waters with moderate to swift currents and depths less than 1 meter (Gordon and Layzer, 1989). Mussels are most often observed in clean, fast-flowing water in substrate which contain relatively firm rubble, gravel, and sand swept-free from siltation; usually buried in shallow riffle and shoal areas (USFWS, 1984; 2010). Typically, V. trabalis is found buried in shallow riffle and shoal areas, often located under large rocks that must be removed by hand to inspect the habitat underneath (USFWS, 2010).
Economic Attributes Not yet assessed
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Management Summary
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Stewardship Overview: This species was listed as federally endangered in the U.S. in 1976 and a recovery plan created (USFWS, 1984). A watershed implementation schedule has been created for the recovery plan (USFWS, 1989).

Recovery objectives (USFWS, 1984) include: (1) preserve populations and presently used habitat with emphasis on Buck Creek, Rockcastle, and the Little South Fork Cumberland River, (2) determine the feasibility of introducing the species back into rivers within its historic range and introduce where feasible, (3) determine the number of individuals required to maintain a viable population, (4) investigate the necessity for habitat improvement, and if necessary and desirable, identify techniques and sites for improvement to include implementation, (4) develop and implement a program to monitor population levels and habitat conditions of presently established populations as well as introduced and expanding populations, (6) assess overall success of recovery program and recommend action.

It is listed Endangered throughout its range, except in the free-flowing reach of the Tennessee River from the base of Wilson Dam downstream to the backwaters of Pickwick Reservoir and the lower 5 RM of all tributaries to this reach in Colbert and Lauderdale Counties, Alabama (USFWS, 2001).

The USFWS, in cooperation with the State of Tennessee and Conservation Fisheries, Inc., proposes to reintroduce this species into its historical habitat in the free-flowing reach of the French Broad River below Douglas Dam to its confluence with the Holston River, Knox County Tennessee, and in the free-flowing reach of the Holston River below Cherokee Dam to its confluence with the French Broad River (USFWS, 2006).

Biological Research Needs: Determine the genetic status of this species and V. perpurpurea, which appears to be a sister taxon to V. trabalis.

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: 15Feb2011
NatureServe Conservation Status Factors Author: Cordeiro, J. (2011); Shelton, Douglas N. (2000)
Element Ecology & Life History Edition Date: 15Feb2011
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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  • Bogan, A.E. 2002. Workbook and key to the freshwater bivalves of North Carolina. North Carolina Museum of Natural Sciences: Raleigh, North Carolina. 101 pp.

  • Bogan, A.E. and P.W. Parmalee. 1983. Tennessee's rare wildlife. Vol. 2: The mollusks. Tennessee Wildlife Resources Agency and the Tennessee Conservation Department: Nashville, Tennessee. 123 pp.

  • Clarke, A.H. 1983. The distribution and relative abundance of Lithasia pinguis (Lea), Pleurobema plenum (Lea), Villosa trabalis (Conrad), and Epioblasma sampsoni (Lea). American Malacological Bulletin, 1: 27-30.

  • Gordon, M.E. and J.B. Layzer. 1989. Mussels (Bivalvia: Unionoidea) of the Cumberland River review of life histories and ecological relationships. U.S. Fish and Wildlife Service Biological Report, 89(15): 1-99.

  • Guyot, J.A. 2005. Restoration of the endangered Cumberland elktoe (Alasmidonta atropurpurea) and Cumberland bean (Villosa trabalis) in the Big South Fork National River and Recreation Area, Tennessee and Kentucky. Master of Science thesis, Virginia Polytechnic Institute and State University, Blacksburg, Virginia.

  • Hoggarth, M.A. 1988. The use of glochidia in the systematics of the Unionidae (Mollusca:Bivalvia). Ph.D. dissertation, Ohio State University, Columbus, OH. 340pp.

  • Howard, A.D. 1915. Some exceptional cases of breeding among the Unionidae. The Nautilus 29:4-11.

  • Johnson, P.D., C. St. Aubin, and S.A. Ahlstedt. 2005. Freshwater mussel survey results for the Cherokee and Chattahoochee districts of the United States Forest Service in Tennessee and Georgia. Report to the U.S. Fish and Wildlife Service, Daphne, Alabama. 32 pp.

  • LeGrand, H.E., Jr., S.P. Hall, S.E. McRae, and J.T. Finnegan. 2006. Natural Heritage Program List of the Rare Animal Species of North Carolina. North Carolina Natural Heritage Program, Raleigh, North Carolina. 104 pp.

  • Lefevre, G. and W.T. Curtis. 1912. Studies on the reproduction and artificial propogation of fresh-water mussels. Bulletin of the Bureau of Fisheries 30:102-201.

  • Mirarchi, R.E., J.T. Garner, M.F. Mettee, and P.E. O'Neil. 2004b. Alabama wildlife. Volume 2. Imperiled aquatic mollusks and fishes. University of Alabama Press, Tuscaloosa, Alabama. xii + 255 pp.

  • Moyle, P. and J. Bacon. 1969. Distribution and abundance of molluscs in a fresh water environment. Journal of the Minnesota Academy of Science 35(2/3):82-85.

  • Ortmann, A.E. 1915. Studies in naiades. The Nautilus, 29: 63-67.

  • Ortmann, A.E. 1918c. The nayades (freshwater mussels) of the Upper Tennessee drainage. With notes on synonymy and distribution. Proceedings of the American Philosophical Society 57: 521-626.

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

  • Parmalee, P.W. and A.E. Bogan. 1998. The freshwater mussels of Tennessee. University of Tennessee Press, Knoxville, Tennesee. 328 pp.

  • Simpson, C.T. 1914. A Descriptive Catalogue of the Naiades or Pearly Fresh-water Mussels. Bryant Walker: Detroit, Michigan. 1540 pp.

  • 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.

  • Turgeon, D.D., A.E. Bogan, E.V. Coan, W.K. Emerson, W.G. Lyons, W.L. Pratt, C.F.E. Roper, A. Scheltema, F.G. Thompson, and J.D. Williams. 1988. Common and scientific names of aquatic invertebrates from the United States and Canada: mollusks. American Fisheries Society Special Publication 16: viii + 277 pp., 12 pls.

  • 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.

  • U. S. Fish and Wildlife Service (USFWS). 1984. Recovery plan for the Cumberland Bean Pearly Mussel Villosa trabalis (Conrad, 1834), U.S. Fish and Wildlife Region 4, Atlanta, Georgia. 58 pp.

  • U.S. Fish and Wildlife Service (USFWS). 2001. Endangered and Threatened Wildlife and Plants; establishment of nonessential experimental population status for 16 freshwater mussels and 1 freshwater snail (Anthony's Riversnail) in the free-flowing reach of the Tennessee River below the Wilson Dam, Colbert and Lauderdale Counties, Alabama. Federal Register, 66(115): 32250-32264.

  • U.S. Fish and Wildlife Service (USFWS). 2006. Endangered and threatened wildlife and plants; establishment of nonessential experimental population status for 15 freshwater mussels, 1 freshwater snail, and 5 fishes in the lower French Broad River and in the lower Holston River, Tennessee; Proposed Rule. Federal Register, 71(113): 34195-34230.

  • U.S. Fish and Wildlife Service (USFWS). 2010. Cumberland bean (Villosa trabalis) 5-year review: Summary and evaluation. U.S. Fish and Wildlife Service, Frankfort, Kentucky. 14 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. 1992a. Unionids, fishes, and the species-area curve. Journal of Biogeography 19:481-490.

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

  • 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.

  • 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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