Uniomerus columbensis - (I. Lea, 1857)
Apalachicola Pondhorn
Taxonomic Status: Accepted
Unique Identifier: ELEMENT_GLOBAL.2.827943
Element Code: IMBIV46060
Informal Taxonomy: Animals, Invertebrates - Mollusks - Freshwater Mussels
 
Kingdom Phylum Class Order Family Genus
Animalia Mollusca Bivalvia Unionoida Unionidae Uniomerus
Genus Size: B - Very small genus (2-5 species)
Check this box to expand all report sections:
Concept Reference
Help
Concept Reference: 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.
Concept Reference Code: B08WIL01EHUS
Name Used in Concept Reference: Uniomerus columbensis
Taxonomic Comments: Appalachicola Basin Uniomerus have variously been recognized as Uniomerus carolinianus (e.g. Heard, 1979; Brim Box and Williams, 2000) and/or Uniomerus declivis (e.g. Heard, 1979; Davis, 1983). However, U. carolinianus may be confined to Atlantic Coast drainages and U. declivis appears to be confined to lower reaches of the Mississippi Basin (A.E. Bogan, unpublished, in Williams et al., 2008). Because of the taxonomic uncertainty, a species of Uniomerus described from the Apalachicola Basin is recognized as Uniomerus columbensis; the earliest available name (Williams et al., 2008).
Conservation Status
Help

NatureServe Status

Global Status: G3
Global Status Last Reviewed: 21May2009
Global Status Last Changed: 21May2009
Rounded Global Status: G3 - Vulnerable
Reasons: Distribution is unclear because it has only recently been recognized. It is considered an Apalachicola River basin endemic by Williams et al. (2008), but further study may reveal its present in adjacent river drainages along the eastern Gulf Coast. At this tiem it appears currently stable throughout its limited, though nebulous, range.
Nation: United States
National Status: N3 (21May2009)

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 (S2), Florida (SNR), Georgia (SNR)

Other Statuses

NatureServe Global Conservation Status Factors

Range Extent: 1000-20,000 square km (about 400-8000 square miles)
Range Extent Comments: Distribution is unclear because it has only recently been recognized. It is considered an Apalachicola River basin endemic by Williams et al. (2008), but further study may reveal its present in adjacent river drainages along the eastern Gulf Coast.

Number of Occurrences: 21 - 80
Number of Occurrences Comments: In the ACF basin, it was recently collected from 28 of 324 sites in Alabama, Florida, and Georgia and is much the same as it was historically except it was only located in a single tributary (Halawakee Creek) of the Chattahoochee River (Brim-Box and Williams, 2000). In a 2004 survey of 24 sites in the Choctawhatchee, Yellow, and Conecuh-Escambia River drainages in southern Alabama, Pilarczyk et al. (2006) found this species (although acknowledged some confusion as to whether it should be listed as Uniomerus carolinianus (likely) or Uniomerus tetralasmus (as cited historically) at four sites (all in the Choctawhatchee River drainage). Specimens of this species were recently found in a survey of ten sites in the Chickasawhatchee Wildlife Management Area in Chickasawhatchee Creek in southwest Georgia (Battle et al., 2003). In 1999 and 2001, this species was found in 13 sites (231 specimens) and 12 sites (427 specimens), respectively, in surveys of 21 sites (each year) in about a dozen tributary streams of the lower Flint River Basin, in southwestern Georgia (Golladay et al., 2004). In 1999, this species was found to comprise 0.79% (relative abundance) of the 14873 mussels collected in surveys of 46 sites in 12 tributary streams of the lower Flint River Basin, Georgia (Gagnon et al., 2006). It is extant in isolated tributaries of the Chattahoochee River and headwaters of the Chipola River in Alabama (Williams et al., 2008).

Population Size: 100,000 - 1,000,000 individuals
Population Size Comments: In 1999, this species was found to comprise 0.79% (relative abundance) of the 14873 mussels collected in surveys of 46 sites in 12 tributary streams of the lower Flint River Basin, Georgia (Gagnon et al., 2006). In 1999 and 2001, this species was found in 10 sites (46 specimens) and 10 sites (74 specimens), respectively, in surveys of 21 sites (each year) in about a dozen tributary streams of the lower Flint River Basin, in southwestern Georgia (Golladay et al., 2004). In the ACF basin, it was recently collected from 28 of 324 sites (74 live, 71 shells) in Alabama, Florida, and Georgia and is much the same as it was historically except it was only located at a single site (Halawakee Creek) of the Chattahoochee River (Brim-Box and Williams, 2000).

Number of Occurrences with Good Viability/Integrity: Few to some (4-40)
Viability/Integrity Comments: In 1999 and 2001, this species was found in 13 sites (231 specimens) and 12 sites (427 specimens), respectively, in surveys of 21 sites (each year) in about a dozen tributary streams of the lower Flint River Basin, in southwestern Georgia (Golladay et al., 2004).

Overall Threat Impact: Unknown
Overall Threat Impact Comments: Following a recent drought from 1999-2001, this species experienced decline in abundance in the Flint River drainage in Georgia as evidenced by surveys in 2001 and 2002 (Chastain et al., 2005).

Short-term Trend: Relatively Stable (<=10% change)
Short-term Trend Comments: In the Apalachicola Basin (ACF basin = formed by Apalachicola, Chattahoochee, and Flint Rivers) of Alabama, Florida, and Georgia, this species is historically known from 79 records from 38 sites and was found in the main channel and tributaries of the Apalachicola, Chipola, Chattahoochee, and Flint Rivers (Brim Box and Williams, 2000). In the ACF basin, it was recently collected from 28 of 324 sites in Alabama, Florida, and Georgia and is much the same as it was historically except for declines in the Chattahoochee River tributaries (Brim-Box and Williams, 2000).

Long-term Trend: Decline of <50% to Relatively Stable
Long-term Trend Comments: In Alabama, it historically occurred in the Chattahoochee River and some tributaries as well as headwater streams of the Chipola River and currently still occurs in isolated tributaries of the Chattahoochee River and Chipola River headwaters (Williams et al., 2008). In the Apalachicola Basin (ACF basin = formed by Apalachicola, Chattahoochee, and Flint Rivers) of Alabama, Florida, and Georgia, this species is historically known from 79 records from 38 sites and was found in the main channel and tributaries of the Apalachicola, Chipola, Chattahoochee, and Flint Rivers (Brim Box and Williams, 2000).

Intrinsic Vulnerability: Not intrinsically vulnerable
Intrinsic Vulnerability Comments: This species is able to endure prolonged periods of dessication. Specimens, if left in fairly cool, but completely dry, conditions, have been known to survive for several months (as one might surmise, the valves of this species close completely).

Environmental Specificity: Broad. Generalist or community with all key requirements common.
Environmental Specificity Comments: This species is probably tolerant of moderate siltation, habitat modifications; typical liabilities of filter-feeders (e.g., to excessive pollutants, eutrophication, etc.). Most other area unionids are thought to be much more fragile than this species.

Other NatureServe Conservation Status Information

Distribution
Help
Global Range: (1000-20,000 square km (about 400-8000 square miles)) Distribution is unclear because it has only recently been recognized. It is considered an Apalachicola River basin endemic by Williams et al. (2008), but further study may reveal its present in adjacent river drainages along the eastern Gulf Coast.

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

Range Map
No map available.

U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
03 Middle Chattahoochee-Lake Harding (03130002), 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), Chipola (03130012)
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Help
Diagnostic Characteristics: Uniomerus columbensis resembles several species of Elliptio, including E. fumalis and E. pullata, but can be distinguished by its cloth-like periostracum. Some species of Elliptio have rays, but adult U. columbensis consistently lack rays. The umbo sculpture of U. columbensis is oblique to the hinge line, but it is not in species of Elliptio. Typically the incurrent aperture papillae of U. columbensis are arborescent, but may be bifid or trifid in some individuals. The papillae of most Apalachicola Basin Elliptio spp. are generally simple, with a few bifid papillae, in some individuals. The exception is Elliptio crassidens, which may have some arborescent papillae. U. columbensis differs conchologically from Uniomerus tetralasmus of Gulf Coast drainages west ot the Apalachicola Basin. U. columbensis is more broadly rounded posteriorly than U. tetralasmus which is often bluntly pointed to narrowly rounded (Williams et al., 2008).
Reproduction Comments: It is presumably a long-term brooder, gravid from late summer or autumn to the following summer. Brim Box and Williams (2000) reported a gravid female during may. Glochidial hosts are not known.
Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Riverine Habitat(s): CREEK, Low gradient, Pool
Lacustrine Habitat(s): Shallow water
Habitat Comments: It occurs in creeks, rivers and floodplain lakes in sand and sandy clay. It can also be found in holes and crevices of limestone substrates (Williams et al., 2008). n a survey of the ACF basin, Brim Box and Williams (2000) found it at sites with primarily sand and clay or sand and limestone rock substrates (69%) and sometimes (21%) at sites with clay and limestone rock substrates.
Economic Attributes Not yet assessed
Help
Management Summary Not yet assessed
Help
Population/Occurrence Delineation
Help
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
Help
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
Help
Authors/Contributors
Help
NatureServe Conservation Status Factors Edition Date: 21May2009
NatureServe Conservation Status Factors Author: Cordeiro, J.
Element Ecology & Life History Edition Date: 21May2009
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
Help
  • Battle, J., S.W. Golladay, and A.R. Bambarger. 2003. Mussel conservation in the Chickasawhatchee and Elmodel Wildlife Management Areas: methods for a relocation study. Pages 860-863 in K.J. Hatcher (ed.) Proceedings of the Georgia Water Resources Conference, Institute of Ecology, The University of Georgia, Athens, Georgia.

  • Chastain, C.A., S.W. Golladay, and T.K. Muenz. 2005. Distribution of unionid mussels in tributaries of the lower Flint River, southwestern Georgia: an examination of current and historical trends. Presented at the Proceedings of the 2005 Georgia Water Resources Conference, 25-27 April 2005, University of Georgia.

  • Gagnon, P., W. Michener, M. Freeman, and J. Brim Box. 2006. Unionid habitat and assemblage composition in coastal plain tributaries of Flint River (Georgia). Southeastern Naturalist, 5(1): 31-52.

  • Golladay, S.W., P. Gagnon, M. Kearns, J.M. Battle, and D.W. Hicks. 2004. Response of freshwater mussel assemblages (Bivalvia: Unionidae) to a record drought in the Gulf Coastal Plain of southwestern Georgia. Journal of the North American Benthological Society, 23(3): 494-506.

  • 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., 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, James D., Arthur Bogan, Robert Butler, Kevin Cummings, Jeffrey Garner, John Harris, Nathan Johnson and G.Thomas 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

  • 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
  • Brim Box, J. and J.D. Williams. 2000. Unionid mollusks of the Apalachicola Basin in Alabama, Florida, and Georgia. Alabama Museum of Natural History Bulletin, 21: 1-143.

  • 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.

Use Guidelines & Citation

Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of March 2019.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2019 NatureServe, 2511 Richmond (Jefferson Davis) Highway, Suite 930, Arlington, VA 22202, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2019. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.