Freshwater Bivalves of Illinois

The following lists were compiled by Kevin Cummings, Alison Stodola, Jeremy Tiemann, and Rachel Vinsel. Distributional data taken from Cummings (1991), Cummings and Mayer (1992), Cummings et al. (1997), Sneen et al. (2009), Tiemann et al. (2013), Stodola et al. (2014), Tiemann et al. (2017), and Stodola et al. (2021). Taxonomy for Unionoida follows Williams et al. (2017), except for most taxonomic updates since the publication.

Special status includes:

  • ST – State Threatened
  • SE – State Endangered
  • FT – Federally Threatened
  • FE – Federally Endangered
  • X – Extirpated
  • (†) – Extinct
  • SGCN – Species in Greatest Conservation Need (Illinois Wildlife Action Plan)
  • W – Watch Llist (Illinois Wildlife Action Plan)
  • I – introduced/non-native

Class Bivalvia

Order Unionoida – Freshwater Mussels (82 species)

Family Margaritiferidae (1 species)

Cumberlandia monodonta (Say, 1829) – Spectaclecase SE, FE

Family Unionidae (81 species)

Alasmidonta marginata Say, 1818 – Elktoe SGCN
Alasmidonta viridis (Rafinesque, 1820) – Slippershell SGCN
Anodontoides ferussacianus (Lea, 1834) – Cylindrical Papershell
Amblema plicata (Say, 1817) – Threeridge
Arcidens confragosus (Say, 1829) – Rock Pocketbook SGCN
Cambarunio iris (Lea, 1829) – Rainbow SE
Cyclonaias nodulata (Rafinesque, 1820) – Wartyback W
Cyclonaias pustulosa (Lea, 1831) – Pimpleback
Cyclonaias tuberculata (Rafinesque, 1820) – Purple Wartyback ST
Cyprogenia stegaria (Rafinesque, 1820) – Fanshell SE, FE
Ellipsaria lineolata (Rafinesque, 1820) – Butterfly ST
Elliptio crassidens (Lamarck, 1819) – Elephantear SE
Epioblasma flexuosa (Rafinesque, 1820) – Leafshell (†), X
Epioblasma obliquata (Rafinesque, 1820) – White Catspaw FE, X
Epioblasma personata (Say, 1829) – Combshell (†), X
Epioblasma phillipsii (Conrad, 1835) – Conrad’s Riffleshell (†), X
Epioblasma propinqua (Lea 1857) – Tennessee Riffleshell (†), X
Epioblasma rangiana (Lea, 1838) – Northern Riffleshell SE, FE
Epioblasma sampsonii (Lea, 1861) – Wabash Riffleshell (†), X
Epioblasma torulosa (Rafinesque, 1820) – Tubercled Blossom FE, X
Epioblasma triquetra (Rafinesque, 1820) – Snuffbox SE, FE
Eurynia dilatata Rafinesque, 1820 – Spike SE
Fusconaia flava (Rafinesque, 1820) – Wabash Pigtoe
Fusconaia subrotunda (Lea, 1831) – Longsolid X
Hemistena lata (Rafinesque, 1820) – Cracking Pearlymussel FE, X
Lampsilis abrupta (Say, 1831) – Pink Mucket SE, FE
Lampsilis cardium Rafinesque, 1820 – Plain Pocketbook
Lampsilis fasciola Rafinesque, 1820 – Wavyrayed Lampmussel SE
Lampsilis higginsii (Lea, 1857) – Higgin’s Eye SE, FE
Lampsilis hydiana (Lea, 1838) – Louisiana Fatmucket SGCN
Lampsilis ovata (Say, 1817) – Pocketbook SGCN
Lampsilis siliquoidea (Barnes, 1823) – Fatmucket
Lampsilis teres (Rafinesque, 1820) – Yellow Sandshell
Lasmigona complanata (Barnes, 1823) – White Heelsplitter
Lasmigona compressa (Lea, 1829) – Creek Heelsplitter SGCN
Lasmigona costata (Rafinesque, 1820) – Flutedshell SGCN
Leaunio lienosa (Conrad, 1834) – Little Spectaclecase SGCN
Leptodea fragilis (Rafinesque, 1820) – Fragile Papershell
Leptodea leptodon (Rafinesque, 1820) – Scaleshell SE FE
Ligumia recta (Lamarck, 1819) – Black Sandshell SGCN
Megalonaias nervosa (Rafinesque, 1820) – Washboard
Obliquaria reflexa Rafinesque, 1820 – Threehorn Wartyback
Obovaria olivaria (Rafinesque, 1820) – Hickorynut
Obovaria retusa (Lamarck, 1819) – Ring Pink FE, X
Obovaria subrotunda (Rafinesque, 1820) – Round Hickorynut X
Ortmanniana ligamentina (Lamarck, 1819) – Mucket
Paetulunio fabalis (Lea, 1831) – Rayed Bean FE, X
Plectomerous dombeyanus (Valenciennes, 1827) – Bankclimber W
Plethobasus cicatricosus (Say, 1829) – White Wartyback FE, X
Plethobasus cooperianus (Lea, 1834) – Orangefoot Pimpleback SE, FE
Plethobasus cyphyus (Rafinesque, 1820) – Sheepnose SE, FE
Pleurobema clava (Lamarck, 1819) – Clubshell SE, FE
Pleurobema cordatum (Rafinesque, 1820) – Ohio Pigtoe SE
Pleurobema plenum (Lea, 1840) – Rough Pigtoe FE, X
Pleurobema rubrum (Rafinesque, 1820) – Pyramid Pigtoe X
Pleurobema sintoxia (Rafinesque, 1820) – Round Pigtoe
Potamilus alatus (Say, 1817) – Pink Heelsplitter
Potamilus capax (Green, 1832) – Fat Pocketbook SE, FE
Potamilus ohiensis (Rafinesque, 1820) – Pink Papershell
Potamilus purpuratus (Lamarck, 1819) – Bleufer SGCN
Ptychobranchus fasciolaris (Rafinesque, 1820) –Kidneyshell SE
Pyganodon grandis (Say, 1829) – Giant Floater
Quadrula fragosa (Conrad, 1835) – Winged Mapleleaf FE, X
Quadrula quadrula (Rafinesque, 1820) – Mapleleaf
Reginaia ebenus (Lea, 1831) – Ebonyshell SE
Sagittunio subrostratus (Say, 1831) – Pondmussel
Simpsonaias ambigua (Say, 1825) – Salamander Mussel SE
Strophitus undulatus (Say, 1817) – Creeper
Theliderma cylindrica (Say, 1817) – Rabbitsfoot FT, SE
Theliderma metanevra (Rafinesque, 1820) – Monkeyface ST
Toxolasma lividium (Rafinesque, 1831) – Purple Lilliput SE
Toxolasma parvum (Barnes, 1823) – Lilliput
Toxolasma texasiense (Lea, 1857) – Texas Lilliput
Tritogonia nobilis (Contrad, 1854) – Gulf Mapleleaf SGCN
Tritogonia verrucosa (Rafinesque, 1820) – Pistolgrip SGCN
Truncilla donaciformis (Lea, 1828) – Fawnsfoot
Truncilla truncata Rafinesque, 1820 – Deertoe
Uniomerus tetralasmus (Say, 1831) – Pondhorn
Utterbackia imbecillis (Say, 1829) – Paper Pondshell
Utterbackiana suborbiculata (Say, 1831) – Flat Floater
Venustaconcha ellipsiformis (Conrad, 1836) – Ellipse SGCN

Order Venerioda

Family Sphaeriidae – Fingernail Clams (27 species)

Eupera cubensis (Prime, 1865) – Mottled Fingernail Clam I
Pisidium adamsi Prime, 1852 – Adam Peaclam
Pisidium casertanum (Poli, 1791) – Ubiquitous Peaclam
Pisidium compressum Prime, 1852 – Ridged-beak Peaclam
Pisidium conventus Clessin, 1877 – Alpine Peaclam
Pisidium cruciatum Sterki, 1895 – Ornamented Peaclam
Pisidium dubium (Say, 1817) – Greater Eastern Peaclam
Pisidium equilaterale Prime, 1852 – Round Peaclam
Pisidium fallax Sterki, 1896 – River Peaclam
Pisidium ferrugineum Prime, 1852 – Rusty Peaclam
Pisidium idahoense Roper, 1890 – Giant Northern Peaclam
Pisidium lilljeborgi (Clessin, 1886) – Lilljeborg Peaclam
Pisidium nitidum Jenyns, 1832 – Shiny Peaclam
Pisidium punctatum Sterki, 1895 – Perforated Peaclam
Pisidium punctiferum (Guppy, 1867) – Striate Peaclam
Pisidium rotundatum Prime, 1852 – Fat Peaclam
Pisidium variabile Prime, 1852 – Triangular Peaclam
Pisidium walkeri Sterki, 1895 – Walker Peaclam
Sphaerium fabale (Prime, 1852) – River Fingernail Clam
Sphaerium lacustre (Müller, 1774) – Lake Fingernail Clam
Sphaerium occidentale (Lewis, 1856) – Herrington Fingernail Clam
Sphaerium partumeium (Say, 1822) – Swamp Fingernail Clam
Sphaerium rhomboideum (Say, 1822) – Rhomboid Fingernail Clam
Sphaerium securis (Prime, 1852) – Pond Fingernail Clam
Sphaerium simile (Say, 1817) – Grooved Fingernail Clam
Sphaerium striatinum (Lamarck, 1818) – Striated Fingernail Clam
Sphaerium transversum (Say, 1829) – Long Fingernail Clam

Family Corbiculidae (3 species)

Corbicula fluminea (Müller, 1774) / Form A I
Corbicula largillierti (Phillipi, 1844) / Form B I
Corbicula sp. / (Form D) I

Family Dreissenidae (2 species)

Dreissena bugensis (Andrusov, 1897) – Quagga Mussel I
Dreissena polymorpha (Pallas, 1771) – Zebra Mussel I

Literature Cited

Cummings, K.S. 1991. The aquatic Mollusca of Illinois. Pp. 429-439 in L.M. Page and M.R. Jeffords, eds. Our living heritage: The biological resources of Illinois. Illinois Natural History Survey Bulletin 34(4):357-477.

Cummings, K.S. and C.A. Mayer. 1992. Field guide to freshwater mussels of the Midwest. Illinois Natural History Survey, Manual 5. 194 pp.

Cummings, K.S., and C.A. Mayer. 1997. Distributional checklist and status of Illinois freshwater mussels (Mollusca: Unionacea). Pp. 129-145 in K.S. Cummings, A.C. Buchanan, C.A. Mayer, and T.J. Naimo, eds. Conservation and management of freshwater mussels II: Initiatives for the future. Proceedings of a UMRCC Symposium, 16-18 October 1995, St. Louis Missouri. Upper Mississippi River Conservation Committee, Rock Island, Illinois. 293 pp.

Sneen, M. E., K. S. Cummings, T. Minarik, Jr., and J. Wasik. 2009. The discovery of the nonindigenous, Mottled Fingernail Clam, Eupera cubensis (Prime, 1865) (Bivalvia: Sphaeriidae) in the Chicago Sanitary and Ship Canal (Illinois River Drainage), Cook County, Illinois. Journal of Great Lakes Research 35:627-629.

Stodola, A.P., S.A. Douglass, and D.K. Shasteen. 2014. Historical and current distributions of freshwater mussels in Illinois. Illinois Natural History Survey Technical Report 2014(37). 82 pp.

Sodola, A.P., C. Lydeard, J.T. Lamer, S.A. Douglass, K.S. Cummings, and D. Campbell. 2021. Hiding in plain sight: genetic confirmation of putative Louisiana Fatmucket Lampsilis hydiana (Mollusca: Unionidae) in Illinois. Freshwater Mollusk Biology and Conservation 24:59-86.

Tiemann, J.S., K.S. Cummings, and J.E. Schwegman. 2013. First occurrence of the Bankclimber Plectomerus dombeyanus (Valenciennes, 1827) (Mollusca: Unionidae) in Illinois. Transactions of the Illinois State Academy of Science 106:1-2.

Tiemann, J.S., A.E. Haponski, S.A. Douglass, T. Lee, K.S. Cummings, M.A. Davis, and D. ÓFoighil. 2017. First record of a putative novel invasive Corbicula lineage discovered in the Illinois River, Illinois, USA. BioInvasions Records 6:159-166.

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.