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Home/Species/ Finerayed Pigtoe

Fusconaia cuneolus

(I. Lea, 1840)

Finerayed Pigtoe

G1Critically Imperiled Found in 6 roadless areas NatureServe Explorer →
G1Critically ImperiledGlobal Rank
EndangeredIUCN
Very highThreat Impact
Finerayed pigtoe (Fusconaia cuneolus). Photo by U.S. Fish & Wildlife Service, Public Domain (U.S. Government Work), via ECOS.
U.S. Fish & Wildlife Service, https://www.usa.gov/government-works
Identity
Unique IDELEMENT_GLOBAL.2.118288
Element CodeIMBIV17050
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryInvertebrate Animal
IUCNEndangered
CITESAppendix I
Endemicendemic to a single nation
KingdomAnimalia
PhylumMollusca
ClassBivalvia
OrderUnionoida
FamilyUnionidae
GenusFusconaia
Other Common Names
Finerayed Pigtoe Pearlymussel (EN)
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.
Taxonomic Comments
In an unpublished study of molecular systematics, Campbell and Harris (2006) found this species was closely related to Fusconaia cor but was distinct.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2023-12-11
Change Date1998-02-26
Edition Date2023-12-11
Edition AuthorsMorrison, M. (1998); Cordeiro, J. (2011); T. Cornelisse (2023)
Threat ImpactVery high
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences1 - 5
Rank Reasons
Due to long and short-term population declines and many ongoing threats, this species has few viable occurrences.
Range Extent Comments
This species occurs in five rivers in the southeastern United States; the North Fork of the Holston River in Virginia, the Clinch and Powell Rivers in Virginia and Tennessee, the Little River in Tennessee, and the Paint Rock River in Alabama (Williams et al. 2008; USFWS 2022; GBIF 2023).
Occurrences Comments
This species is known from five extant populations (USFWS 2022).
Threat Impact Comments
This species is threatened by sedimentation, nutrient, and chemical pollution from land conversion activities, including agriculture, resource extraction, and coal mining, toxic chemical spills, dams and water diversions that change hydrological conditions, host fish distribution, and prevent habitat connectivity and recolonization, and lethal epidemics caused by densoviruses (USFWS 2022).
Ecology & Habitat

Habitat

This species inhabits clear, high gradient streams in firm cobble and gravel substrates (Neves 1984).

Reproduction

This species is a short-term brooder (USFWS 2013).
Other Nations (1)
United StatesN1
ProvinceRankNative
AlabamaS1Yes
TennesseeS1Yes
VirginiaS1Yes
Threat Assessments
ThreatScopeSeverityTiming
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 (31-70%)Serious or 31-70% pop. declineHigh (continuing)
9.1 - Domestic & urban waste waterLarge - restrictedSerious - moderateHigh (continuing)
9.1.2 - Run-offLarge - restrictedSerious - moderateHigh (continuing)
9.2 - Industrial & military effluentsLarge - restrictedSerious - moderateHigh (continuing)
9.3 - Agricultural & forestry effluentsLarge - restrictedSerious - moderateHigh (continuing)
9.3.2 - Soil erosion, sedimentationLarge - restrictedSerious - moderateHigh (continuing)

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Roadless Areas (6)
Idaho (1)
AreaForestAcres
Bear CreekCaribou-Targhee National Forest118,582
Virginia (5)
AreaForestAcres
Bear CreekJefferson National Forest18,274
Beartown Addition AJefferson National Forest1,370
Beartown Addition BJefferson National Forest2,985
Garden MountainJefferson National Forest3,960
Hunting Camp Little Wolf CreekJefferson National Forest8,953
References (43)
  1. Ahlstedt, A. and R.J. Neves. 1984. Species List of Mussels Occurring at Pendleton Island.
  2. Ahlstedt, S.A. 1983. The molluscan fauna of the Elk River in Tennessee and Alabama. American Malacological Bulletin 1:43-50.
  3. Ahlstedt, S.A. 1984. Twentieth century changes in the freshwater mussel fauna of the Clinch River (Tennessee and Virginia). M.S. Thesis, The University of Tennessee, Knoxville, Tennessee. 102 pp.
  4. Ahlstedt, S.A. 1995-1996. Status survey for federally listed endangered freshwater mussel species in the Paint Rock River system, northeastern Alabama, U.S.A. Walkerana 8(19):63-80.
  5. Ahlstedt, S. A. Tennessee Valley Authority.
  6. Barr, W.C., S.A. Ahlstedt, G.D. Hickman, and D.M. Hill. 1993-1994. Cumberlandian mollusk conservation program. Activity 8: Analysis of macrofauna factors. Walkerana 7(17/18):159-224.
  7. Beaty, Braven. The Nature Conservancy - Virginia Chapter, Southwest Area Steward. Abingdon, VA.
  8. Biological Resources Division, USGS. 1997. Database of museum records of aquatic species. Compiled by J. Williams (USGS-BRD, Gainesville, FL).
  9. Bogan, Art (Curator of Aquatic Invertebrates, North Carolina State Museum of Natural Sciences). 1997. Review and annotation of mussel watershed distribution maps for TN. Review requested by Ruth Mathews, TNC. September 1997.
  10. Bruenderman, S.A. and R.J. Neves. 1993. Life history of the endangered fine-rayed pigtoe, <i>Fusconaia cuneolus</i> (Bivalvia: Unionidae) in the Clinch River, Virginia. American Malacological Bulletin, 10(1): 83-91.
  11. Campbell, D. and P. Harris. 2006. Report on molecular systematics of poorly-known freshwater mollusks of Alabama. Report to the Alabama Department of Conservation and Natural Resources, Montgomery, Alabama. 34 pp.
  12. Fraley, S.J. and S.A. Ahlstedt. 2000. The recent decline of the native mussels (Unionidae) of Copper Creek, Russell and Scott Counties, Virginia. Pages 189-195 in R.A. Tankersley, D.I. Warmolts, G.T. Watters, B.J. Armitage, P.D. Johnson, and R.S. Butler (eds.). Freshwater Mollusk Symposia Proceedings. Ohio Biological Survey, Columbus, Ohio. 274 pp.
  13. 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
  14. 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.
  15. Hanlon, S.D., M.A. Petty, and R.J. Neves. 2009. Status of native freshwater mussels in Copper Creek, Virginia. Southeastern Naturalist 8(1):1-18.
  16. Howard, A. D. 1915. Some exceptional cases of breeding among the Unionidae. The Nautilus 29:4-11.
  17. Isom, B. G. and P. Yokley, Jr. 1973. The mussels of the Flint and Paint Rock River Systems of the southwest slope of the Cumberland Plateau in North Alabama-1965 and 1967. The American Midland Naturalist 89(2):442-446.
  18. Isom, B.G., P. Yokley, Jr., and C.H. Gooch. 1973. Mussels of Elk River Basin in Alabama and Tennessee- 1965-1967. American Midland Naturalist 89(2):437-442.
  19. Jones, J.W., R.J. Neves, M.A. Patterson, C.R. Good, and A. DiVittorio. 2001. A status survey of freshwater mussel populations in the upper Clinch River, Tazewell County, Virginia. Banisteria 17: 20-30.
  20. Lefevre, G. and W. T. Curtis. 1912. Studies on the reproduction and artificial propagation of fresh-water mussels. Bulletin of the Bureau of Fisheries 30:102-201.
  21. Major, Smoot (Tennessee Division of Natural Heritage). 1997. Review and annotation of fish and mussel watershed distribution maps. Review requested by Ruth Mathews, TNC on 19 August 1997.
  22. Mirarchi, R.E., et al. 2004a. Alabama Wildlife. Volume One: A Checklist of Vertebrates and Selected Invertebrates: Aquatic Mollusks, Fishes, Amphibians, Reptiles, Birds, and Mammals. University of Alabama Press: Tuscaloosa, Alabama. 209 pp.
  23. 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.
  24. MolluscaBase eds. 2024. MolluscaBase. Accessed at https://www.molluscabase.org
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  26. Neves, Richard (Dick). Department of Fisheries and Wildlife Sciences. Virginia Polytechnic Institute and State University. Blacksburg, VA.
  27. Neves, R.J. 1991. Mollusks. Pages 251-320 in K. Terwilliger (ed.). Virginia's Endangered Species. Proceedings of a Symposium, Department of Game and Inland Fisheries. McDonald and Woodward Publishing Company, Blacksburg, Virginia. 672 pp.
  28. Parmalee, P.W. and A.E. Bogan. 1998. The Freshwater Mussels of Tennessee. University of Tennessee Press: Knoxville, Tennessee. 328 pp.
  29. 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.
  30. Strayer, D. L. 1999. Use of flow refuges by unionid mussels in rivers. Journal of the North American Benthological Society 18(4):468-476.
  31. Strayer, D. L., and J. Ralley. 1993. Microhabitat use by an assemblage of stream-dwelling unionaceans (Bivalvia) including two rare species of <i>Alasmidonta</i>. Journal of the North American Benthological Society 12(3):247-258.
  32. 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.
  33. U.S. Fish and Wildlife Service (USFWS). 1984. Technical draft recovery plan for the fine-rayed pigtoe pearly mussel; <i>Fusconaia cuneolus</i>, U.S. Fish and Wildlife Service, Region 4, Atlanta, Georgia. 60 pp.
  34. 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.
  35. 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.
  36. U.S. Fish and Wildlife Service (USFWS). 2013. Finerayed Pigtoe <i>Fusconaia cuneolus</i>, five year review: summary and evaluation. U.S. Fish and Wildlife Service Southeast Region Asheville Ecological Services Field Office Asheville, North Carolina. 23 pp.
  37. U.S. Fish and Wildlife Service (USFWS). 2022. Finerayed Pigtoe Fusconaia cuneolus, five year review: summary and evaluation. U.S. Fish and Wildlife Service Southeast Region Asheville Ecological Services Field Office Asheville, North Carolina. 22 pp.
  38. Van der Schalie, H. 1938. The naiad fauna of the Huron River in southeastern Michigan. Miscellaneous Publication of the Museum of Zoology, University of Michigan 40:7-78.
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  40. Watters, G. T. 1992. Unionids, fishes, and the species-area curve. Journal of Biogeography 19:481-490.
  41. 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.
  42. 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.
  43. 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.