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Ptychobranchus greenii

(Conrad, 1834)

Triangular Kidneyshell

G1Critically Imperiled (G1G2) Found in 5 roadless areas NatureServe Explorer →
G1Critically ImperiledGlobal Rank
EndangeredIUCN
Very high - highThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.827877
Element CodeIMBIV38020
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryInvertebrate Animal
IUCNEndangered
Endemicendemic to a single state or province
KingdomAnimalia
PhylumMollusca
ClassBivalvia
OrderUnionoida
FamilyUnionidae
GenusPtychobranchus
Synonyms
Ptychobranchus greeni(Conrad, 1834)
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
Spelling of Ptychobranchus greenii is correct as of Turgeon et al. (1998). This species exhibits variable shell morphology and may be confused with some species of Pleurobema . Ecomorphs of the species are best identified by process of elimination (U.S. Fish and Wildlife Service, 1993). Ptychobranchus foremanianus was placed in the synonymy of Ptychobranchus greenii by most previous works. It is recognized in Williams et al. (2008) based on subtle differences in shell coloration, as noted by Ortmann (1923). Preliminary genetic analyses suggest at least two species in the Mobile Basin (K.J. Roe, pers. comm.). The species is now split into Ptychobranchus greenii (Black Warrior and Tombigbee basins) and Ptychobranchus foremanianus (Alabama, Cahaba, Coosa basins).
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 Extent5000-20,000 square km (about 2000-8000 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 in the Coosa and Cahaba Rivers in Alabama, USA (Williams et al. 2008; USFWS 2008, 2019; GBIF 2024).
Occurrences Comments
This species is known from 17 occurrences in 13-18 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 oval to elliptical in outline. The shell is generally compressed, and may be flattened ventral to the umbos. The posterior ridge is broadly rounded and terminates in a broadly rounded point post-ventrally. The pseudocardinal teeth are heavy, and the laterals are heavy, gently curved and short. The periostracum is straw-yellow in young specimens, but becomes yellow-brown in older ones. It may have fine and wavy, or wide and broken, green rays anterior to the posterior ridge (USFWS 2003).

Habitat

This species is found in shoals and runs of small creeks to large rivers with moderate to high currents and sand or gravel substrates (Parmalee and Bogan 1998; USFWS 2000).

Reproduction

This species is a long-term brooder gravid from fall to the following spring or summer (USFWS 2019).
Other Nations (1)
United StatesN1
ProvinceRankNative
AlabamaS1Yes
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)
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 (5)
Alabama (2)
AreaForestAcres
Cheaha ATalladega National Forest236
Oakey MountainTalladega National Forest6,129
Georgia (3)
AreaForestAcres
Foster BranchChattahoochee National Forest171
Ken MountainChattahoochee National Forest527
Pink KnobChattahoochee National Forest12,127
References (25)
  1. Biological Resources Division, USGS. 1997. Database of museum records of aquatic species. Compiled by J. Williams (USGS-BRD, Gainesville, FL).
  2. 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
  3. Global Biodiversity Information Facility (GBIF). 2024. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2024).
  4. 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.
  5. Haag, W. R., and M. L. Warren, Jr. 1997. Host fishes and reproductive biology of 6 freshwater mussel species from the Mobile Basin, USA. Journal of the North American Benthological Society, 16(3): 576-585.
  6. 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.
  7. 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.
  8. MolluscaBase eds. 2024. MolluscaBase. Accessed at https://www.molluscabase.org
  9. Ortmann, A.E. 1923. Notes on the anatomy and taxonomy of certain Lampsilinae from the Gulf drainage. The Nautilus 37(3):56-60.
  10. Pierson, J. M. 1992. A survey of freshwater mussels of the upper North River system in the vicinity of the proposed Tom Bevill Reservoir, Fayette and Tuscaloosa Counties, Alabama. Unpublished report submitted to Almon Associates. 31 pp. + fieldnotes.
  11. 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.
  12. United States Fish and Wildlife Service (USFWS). 2019. Recovery Plan Revision for the Endangered Triangular Kidneyshell (<i>Ptychobranchus greenii</i>). Atlanta, Georgia. 7 pp.
  13. 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.
  14. U.S. Fish and Wildlife Service (USFWS). 1997. Draft Recovery Plan for the Mobile River basin aquatic ecosystem. U.S. Fish and Wildlife Service, Southeast Region, Atlanta, Georgia.
  15. 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.
  16. 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.
  17. 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.
  18. 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.
  19. 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.
  20. 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.
  21. Vaughn, C.C. 2018. Ecosystem services provided by freshwater mussels. Hydrobiologia, 810: 15-27.
  22. 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.
  23. 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.
  24. 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.
  25. 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.