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Ohio Standardized Freshwater Mussel ID Test

Anyone who wishes to conduct mussel surveys in Ohio will need to have passed the Standardized Freshwater Mussel Identification Test. This includes individuals already possessing federal permits for freshwater mussels.

Tests are administered by appointment only and at the discretion of the Division of Mollusks of The Ohio State University Museum of Biological Diversity (MBD). Records of scores for each test attempt, successful or unsuccessful, are maintained by the MBD Division of Mollusks and the Ohio Department of Natural Resources, Division of Wildlife.

 Book your test appointment

  • The test is available twice a day, between 10:30AM and 6PM, Tuesdays, Thursdays, and Fridays by appointment only. Appointments can be made one (1) week to 45 days in advance, using the online booking system linked above.
  • The test will be delivered at the Museum of Biological Diversity of The Ohio State University, 1315 Kinnear Rd., Columbus, OH 43212.
  • Hourly parking at the museum is available through the Parkmobile website and mobile app. You can pre-pay online, or pay when you arrive using the app. The Museum's parking lot is Parkmobile Zone #69346.

  • If visiting for >4 hours, purchasing a Surface Day Pass ($9.75/day) from OSU Campusparc is cheaper.

  • Parking at the museum is free for government-owned vehicles.

Test format and rules:

  1. The test includes extant unionid mussel species found in Ohio. Some species occur more than once. Some may not occur at all. A list of species is available at the bottom of this page.
  2. The test is a simple fill-in-the-blank identification test. There are 100 blanks on the test, and a set of 100 numbered unionid mussel specimens you must identify.
  3. The valves of test specimens are glued shut, so internal characters cannot be examined for identification. This simulates the difficulty of identifying live mussels.
  4. You may return to any previous specimens as needed, and may compare specimens freely (you have all 100 specimens available to you from the beginning of the test.)
    • If you intentionally damage a specimen, or if you make a mess (mix up the order of the specimens), you automatically fail the test. This is easy to avoid!
  5. To pass the test, you must correctly identify:
    • 100% of federally listed mussel species
    • at least 80% of Ohio threatened & endangered species
    • at least 80% of the species on the test overall
  6. The locality from which each specimen on the test was collected is available upon request.
  7. Once started, the test must be completed within three (3) hours.
    • Bathroom / snack breaks may be taken at your discretion, without permission.
  8. The test can be administered to two people at once, who may be asked to share a room.
    • You may not share a room / time slot with another person from your institution/organization.
    • If you are more comfortable taking the test by yourself, please mention it when you make your appointment.
  9. The test is “open book” so you may bring outside sources (books, notes, photographs, etc) to the test, provided they are on paper.
  10. No outside phones, computers, or tablets are allowed in the room with you while you take the test.
  11. You may retake the test as many times as you wish, but the entire test must be retaken each time. In general, you must allow at least one (1) week in between attempts.
    • Exceptions to the waiting period may be made for test takers who have traveled long distances to take the test, at the discretion of Division staff.
  12. After passing the test, you will receive a Certificate of Completion, valid for five-years from the date of the test.
    • You must schedule and re-take the test within this time-period to continue as an approved mussel surveyor.

Please e-mail the Curator of Mollusks, Nate Shoobs (invertebrates@osu.edu) if you have questions about the test.

See the ODNR Division of Wildlife document "Ohio Mussel Survey Protocol" for more information.


Each of these species occurs on the identification test at least once. This list is arranged alphabetically by current genus name, following the taxonomy in Graf & Cummings (2021) and MolluscaBase (2023). Each common name is followed by the scientific name in (parentheses). Where the current taxonomy differs from that of Watters et al. (2009), the previous name is given in [brackets]. Species in bold preceded by *** are Ohio and Federally Endangered or Threatened and must be answered 100 % correctly to pass the test. Species in bold preceded by a * are Ohio Endangered or Threatened and must be answered 80 % correctly to pass the test. A score of at least 80% for all test specimens is needed to pass the test. Synonyms, standard abbreviations, and common names are acceptable forms for answers.

  1. Elktoe (Alasmidonta marginata)
  2. Slippershell Mussel (Alasmidonta viridis)
  3. Threeridge (Amblema plicata)
  4. Cylindrical Papershell (Anodontoides ferussacianus)
  5. *Rainbow (Cambarunio iris) [=Villosa iris]
  6. Purple Wartyback (Cyclonaias tuberculata)
  7. *Wartyback (Cyclonaias nodulata) [=Quadrula nodulata]
  8. Pimpleback (Cyclonaias pustulosa) [=Quadrula p. pustulosa]
  9. ***Fanshell (Cyprogenia stegaria)
  10. *Butterfly (Ellipsaria lineolata)
  11. *Elephantear (Elliptio crassidens)
  12. ***White Catspaw (Epioblasma perobliqua) [=E. obliquata perobliqua]
  13. ***Northern Riffleshell (Epioblasma rangiana) [=E. torulosa rangiana]
  14. ***Purple Catspaw (Epioblasma obliquata)
  15. ***Snuffbox (Epioblasma triquetra)
  16. Spike (Eurynia dilatata) [=Elliptio dilatata]
  17. Wabash Pigtoe (Fusconaia flava)
  18. ***Longsolid (Fusconaia subrotunda)
  19. ***Pink Mucket (Lampsilis abrupta)
  20. Plain Pocketbook (Lampsilis cardium)
  21. Wavy-Rayed Pocketbook (Lampsilis fasciola)
  22. *Pocketbook (Lampsilis ovata)
  23. Fatmucket (Lampsilis siliquoidia) [=L. radiata luteola]
  24. *Yellow Sandshell (Lampsilis teres)
  25. White Heelsplitter (Lasmigona complanata)
  26. Creek Heelsplitter (Lasmigona compressa)
  27. Fluted Shell (Lasmigona costata)
  28. *Little Spectaclecase (Leaunio lienosus) [=Villosa lienosa]
  29. *Black Sandshell (Ligumia recta)
  30. *Washboard (Megalonaias nervosa)
  31. *Threehorn Wartyback (Obliquaria reflexa)
  32. ***Round Hickorynut (Obovaria subrotunda)
  33. Mucket (Ortmanniana ligamentina) [=Actinonaias ligamentina carinata]
  34. ***Rayed Bean (Paetulunio fabalis) [=Villosa fabalis]
  35. ***Sheepnose (Plethobasus cyphyus)
  36. ***Clubshell (Pleurobema clava)
  37. *Ohio Pigtoe (Pleurobema cordatum)
  38. *Pyramid Pigtoe (Pleurobema rubrum)
  39. Round Pigtoe (Pleurobema sintoxia)
  40. Pink Heelsplitter (Potamilus alatus)
  41. Fragile Papershell (Potamilus fragilis) [=Leptodea fragilis]
  42. Pink Papershell (Potamilus ohiensis)
  43. Kidneyshell (Ptychobranchus fasciolaris)
  44. Eastern Floater (Pyganodon cataracta) [=P. cataracta marginata]
  45. Giant Floater (Pyganodon grandis)
  46. Mapleleaf (Quadrula quadrula)
  47. *Ebonyshell (Reginaia ebenus) [=Fusconaia ebenus]
  48. *Eastern Pondmussel (Sagittunio nasutus) [=Ligumia nasuta]
  49. Salamander Mussel (Simpsonaias ambigua)
  50. Creeper (Strophitus undulatus)
  51. ***Rabbitsfoot (Theliderma cylindrica) [=Quadrula c. cylindrica]
  52. *Monkeyface (Theliderma metanevra) [=Quadrula metanevra]
  53. *Purple Lilliput (Toxolasma lividum)
  54. Lilliput Shell (Toxolasma parvum)
  55. Pistolgrip (Tritogonia verrucosa)
  56. *Fawnsfoot (Truncilla donaciformis)
  57. Deertoe (Truncilla truncata)
  58. *Pondhorn (Uniomerus tetralasmus)
  59. Paper Pondshell (Utterbackia imbecillis)
  60. Flat Floater (Utterbackiana suborbiculata) [=Anodonta suborbiculata]