Potamilus ohiensis
Pink papershell

Key Characteristics

The pink papershell is a medium to large-sized mussel (to approximately 6.5 inches) with a fragile, compressed shell, narrow and foward-pointing beak, and prominent posterior wing. Shell color ranges from tan or olive green to dark brown with a pink or purple nacre.

Status and Rank

  • State Status: T
  • State Rank: SNR
  • Global Rank: G5


County NameNumber of OccurrencesYear Last Observed
St. Clair12009
Distribution map for Potamilus ohiensis

Updated 5/15/2018. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


Preferring lakes and large river systems, the pink papershell is often found in the silty sand or mud of slackwater areas. This species may also inhabit impoundments (Watters et. al 2009).

Specific Habitat Needs

needed in Mainstem Stream (3rd-4th order), Pool, Mainstem Stream (3rd-4th order), Run, River (5th-6th order), Riffle, River (5th-6th order), Pool, River (5th-6th order), Run, Inland Lake, Littoral, Benthic, Inland Lake, Pelagic, Benthic

Natural Community Types


For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.


In order to preserve freshwater mussel diversity, host fish populations on which the glochidia rely must also be managed. Dam building, bridge construction, dredging, and other alterations to habitat structure can inhibit the movement of host fish as well as introduce harmful sedimentation into waterways. As all unionid mussels are extremely vulnerable to chemical pollutants (Bringolf 2007) and heavy metals (Pip 1994), pesticide and  herbicide use, industrial waste, mine drainage and urban run-off should be limited where the pink papershell may be present. Zebra mussels infest the shells of native mussels, inhibiting movement and feeding, and sometimes lead to the extirpation of entire communities (Schloesser et al. 1996). The spread of zebra mussels can be prevented by cleaning boat hulls, trailers, scuba and fishing gear before moving between waterways.

Active Period

Gravid from first week of July to fourth week of June

Survey Methods

Visual and tactile search using scuba or glass-bottom buckets. Tactile search (by hand) is especially important where water turbidity and pebbles/rocks make visual detection difficult. After identification, live mussels should be planted back into the substrate anterior end down. Surveys should not take place after heavy rains or during periods of high water as these conditions can make detection much more difficult.  Methods of documenting survey effort include: searching a large measured area, e.g. 128m2; taking multiple quadrat samples; and recording search time (person hours).  For all methods, at least some excavation of substrate (by hand, 5-10cm down) should be done to detect buried mussels.  Searching a large measured area or timed searches are generally better for detecting rare species and generating a species list than quadrat sampling.  These two methods allow more types of microhabitats and a larger area to be covered.  Quadrat sampling is better suited for documenting changes in density and other statistical analyses at the site level (Strayer and Smith 2003).

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed Aug 17, 2018]


Survey References

Technical References

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