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Pleurobema perovatum

(Conrad, 1834)

Ovate Clubshell

G1Critically Imperiled (G1G2) Found in 1 roadless area NatureServe Explorer →
G1Critically ImperiledGlobal Rank
ExtinctIUCN
Very high - highThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.827809
Element CodeIMBIV35230
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryInvertebrate Animal
IUCNExtinct
Endemicendemic to a single nation
KingdomAnimalia
PhylumMollusca
ClassBivalvia
OrderUnionoida
FamilyUnionidae
GenusPleurobema
Synonyms
Pleurobema flavidulum(I. Lea, 1861)Pleurobema johannis(I. Lea, 1859)Pleurobema nux(I. Lea, 1852)Pleurobema simulans(I. Lea, 1871)
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.
Taxonomic Comments
The taxonomy of Pleurobema perovatum can be confusing. Pleurobema hanleyanum and Pleurobema troschelianum are among those with which it is easily confused. A form called Pleurobema pinkstoni is found in Chewacla Creek, Tallapoosa River drainage in Macon County, Alabama, and may be a valid species (Doug Shelton, pers. obs. 1996). Due to the terminal umbos in some specimens, P. perovatum may be mistaken for young P. decisum. They may be distinguished from the latter by their thinner shells and gentle posterior slope (USFWS, 1993). Pleurobema flavidulum has been synonymized by Williams et al. (2008, 2017).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-01-02
Change Date2024-01-02
Edition Date2024-01-02
Edition AuthorsCordeiro, J. (2009); rev. T. Cornelisse (2024)
Threat ImpactVery high - high
Range Extent5000-200,000 square km (about 2000-80,000 square miles)
Number of Occurrences6 - 20
Rank Reasons
This species has a small range and despite populations appearing stable in the short-term, it is subject to many threats and has experienced historical population declines.
Range Extent Comments
This species occurs in the Mobile Basin of Alabama and Mississippi, USA (Williams et al. 2008; USFWS 2019; GBIF 2024).
Occurrences Comments
This species is known from 15 occurrences in 9-16 river drainages using a 2 km separation distance and records from 2000-2023 (USFWS 2008, 2019; GBIF 2024).
Threat Impact Comments
This species is threatened by sedimentation, nutrient, and chemical pollution from land conversion activities, including agriculture, oil and gas operations, and coal mining, dams and water diversions that change hydrological conditions, host fish distribution, and prevent habitat connectivity and recolonization, and habitat alteration due to climate change, including increased water temperatures and drought (USFWS 2008, 2019).
Ecology & Habitat

Description

This species is small to medium-sized with a shell oval to ellipticaql in shape with nearly terminal, inflated umbos. The posterior ridge is well-developed, broadly rounded, and often concave. The posterior slope is produced well beyond the posterior ridge. Periostracum color varies from yellow to dark brown, and occasionally has broad green rays that may cover most of the umbo and posterior ridge. The nacre is white (USFWS 2003).

Habitat

This species is found in sand and gravel shoals and runs of small rivers and large streams with a moderate current (Parmalee and Bogan 1998; USFWS 2000).
Other Nations (1)
United StatesN1
ProvinceRankNative
AlabamaS1Yes
MississippiS1Yes
TennesseeSHYes
Threat Assessments
ThreatScopeSeverityTiming
3 - Energy production & miningLarge - restrictedSerious - moderateHigh (continuing)
3.2 - Mining & quarryingLarge - restrictedSerious - moderateHigh (continuing)
7 - Natural system modificationsLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)
7.2 - Dams & water management/useLarge (31-70%)Serious or 31-70% pop. declineHigh (continuing)
9 - PollutionLarge - restrictedSerious - moderateHigh (continuing)
9.3 - Agricultural & forestry effluentsLarge - restrictedSerious - moderateHigh (continuing)
9.3.2 - Soil erosion, sedimentationLarge - restrictedSerious - moderateHigh (continuing)
11 - Climate change & severe weatherLarge - restrictedModerate or 11-30% pop. declineHigh (continuing)
11.1 - Habitat shifting & alterationLarge - restrictedModerate or 11-30% pop. declineHigh (continuing)

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Roadless Areas (1)
Alabama (1)
AreaForestAcres
Oakey MountainTalladega National Forest6,129
References (32)
  1. Academy of Natural Sciences of Philadelphia (ANSP) Mollusks Department collections. Philadelphia, PA.
  2. Biological Resources Division, USGS. 1997. Database of museum records of aquatic species. Compiled by J. Williams (USGS-BRD, Gainesville, FL).
  3. Campbell, David, Department of Biological Sciences, Biodiversity and Systematics, University of Alabama,Tuscaloosa, AL
  4. Florida Museum of Natural History (FLMNH) Mollusks Department collections. Gainesville, FL.
  5. Freshwater Mollusk Conservation Society (FMCS). 2023. The 2023 checklist of freshwater bivalves (Mollusca: Bivalvia: Unionida) of the United States and Canada. Considered and approved by the Bivalve Names Subcommittee October 2023. Online: https://molluskconservation.org/MServices_Names-Bivalves.html
  6. Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  7. Graf, D.L. and K.S. Cummings. 2021. A 'big data' approach to global freshwater mussel diversity (Bivalvia: Unionoida), with an updated checklist of genera and species. Journal of Molluscan Studies 87(1):1-36.
  8. Hartfield, Paul. (US Fish and Wildlife Service Field Office, Jackson, MS). 1997. Review and annotation of mussel watershed distribution maps. Review requested by Christine O'Brien, USGS-BRD. June 1997.
  9. Johnson, P.D. and S.A. Ahlstedt. 2005. Results of a brief survey for freshwater mussels in the Yellow Creek Watershed, Lowndes County, Mississippi and Lamar and Fayette Counties, Alabama. Report to the U.S. Fish and Wildlife Service, Daphne, Alabama. Unpainated.
  10. 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.
  11. Mann, Tom. (Mississippi Natural Heritage Program. Mississippi Museum of Natural Science). 1997. Review and annotation of fish and mussel watershed distribution maps. Review requested by Ruth Mathews, TNC.
  12. McGregor, S.W., et. al. 1996. Survey of the primary tributaries of the Alabama and lower Tombigbee Rivers for listed and candidate species of mussels, snails, and crayfish: 1994-96.
  13. McGregor, S.W., P.E. O'Neil, and J.M. Pierson. 2000. Status of the freshwater mussel (Bivalvia: Unionidae) fauna of the Cahaba River system, Alabama. Walkerana, 11(26): 215-237.
  14. McGregor, S.W., T.E. Shepard, T.D. Richardson, and J.F. Fitzpatrick, Jr. 1999. A survey of the primary tributaries of the Alabama and Lower Tombigbee rivers for freshwater mussels, snails, and crayfish. Geological Survey of Alabama, Circular 196. 29 pp.
  15. 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.
  16. MolluscaBase eds. 2024. MolluscaBase. Accessed at https://www.molluscabase.org
  17. Parmalee, P.W. and A.E. Bogan. 1998. The Freshwater Mussels of Tennessee. University of Tennessee Press: Knoxville, Tennessee. 328 pp.
  18. Shelton, Douglas N. Alabama Malacological Research Center, Mobile, AL. Personal communication.
  19. 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.
  20. United States Fish and Wildlife Service (USFWS). 2019. Recovery Plan Revision for the Endangered Ovate Clubshell (<i>Pleurobema perovatum</i>). Atlanta, Georgia. 5 pp.<br/>
  21. U.S. Fish and Wildlife Service (USFWS). 1993. Endangered status for eight freshwater mussels and threatened status for three freshwater mussels in the Mobil River drainage. Final rule. Federal Register, 58(60): 14330-14340.
  22. U.S. Fish and Wildlife Service (USFWS). 2000. Recovery plan for the Mobile River basin aquatic ecosystem. U.S. Fish and Wildlife Service, Southeast Region, Atlanta, Georgia. 128 pp.
  23. U.S. Fish and Wildlife Service (USFWS). 2003. Endangered and Threatened Widlife and plants; proposed designation of critical habitat for three threatened mussels and eight endangered mussels in the Mobile River basin; proposed rule. Federal Register, 68(58): 14752-14832.
  24. U.S. Fish and Wildlife Service (USFWS). 2004. Endangered and Threatened Widlife and plants; designation of critical habitat for three threatened mussels and eight endangered mussels in the Mobile River basin; final rule. Federal Register, 69(126): 40083-40171.
  25. U.S. Fish and Wildlife Service (USFWS). 2008. Fine-lined pocketbook (<i>Hamiota </i>(=<i>Lampsilis</i>) <i>altilis</i>), orange-nacre mucket (<i>Hamiota </i>(=<i>Lampsilis</i>) <i>perovalis</i>), Alabama moccasinshell (<i>Medionidus acutissimus</i>) Coosa moccasinshell (<i>Medionidus parvulus</i>), Southern clubshell (<i>Pleurobema decisum</i>), dark pigtoe (<i>Pleurobema furvum</i>), southern pigtoe (<i>Pleurobema georgianum</i>), ovate clubshell (<i>Pleurobema perovatum</i>), triangular kidneyshell (<i>Ptychobranchus greenii</i>), upland combshell (<i>Epioblama metastriata</i>), and southern acornshell (<i>Epioblasma othcaloogensis</i>), 5-Year Review: Summary and Evaluation. Jackson, MS. 37pp.
  26. U.S. Fish and Wildlife Service (USFWS). 2019a. Finelined Pocketbook (<i>Hamiota</i> (=<i>Lampsilis</i>) <i>altilis</i>), Orangenacre Mucket (<i>Hamiota</i> (=<i>Lampsilis</i>) <i>perovalis</i>), Alabama Moccasinshell (<i>Medionidus acutissimus</i>), Coosa Moccasinshell (<i>Medionidus parvulus</i>), Southern Clubshell (<i>Pleurobema decisum</i>), Dark Pigtoe (<i>Pleurobema furvum</i>), Southern Pigtoe (<i>Pleurobema georgianum</i>), Ovate Clubshell (<i>Pleurobema perovatum</i>, Triangulua Clubshell (<i>Pleurobema greenii</i>), 5-year review: summary and evaluation. U.S. Fish and Wildlife Service, South Atlantic-Gulf Region (Region 2), Alabama Ecological Services Field Office, Daphne, Alabama. 69 pp.
  27. U.S. Fish and Wildlife Service (USFWS). 2023. Initiation of 5-Year Status Reviews for 67 Southeastern Species. Notice of initiation of reviews; <br/>request for information. Federal Register 88(91): 30324-30328.
  28. Vaughn, C.C. 2018. Ecosystem services provided by freshwater mussels. Hydrobiologia, 810: 15-27.
  29. 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.
  30. 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.
  31. 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.
  32. Williams, J. D., M. L. Warren, Jr., K. S. Cummings, J. L. Harris, and R. J. Neves. 1993. Conservation status of freshwater mussels of the United States and Canada. Fisheries 18(9):6-22.