Plants and Animals

Stagnicola woodruffi Coldwater pondsnail

Key Characteristics

The coldwater pondsnail is characterized by an elongate and inflated medium sized shell (about a half-inch long) of a cream to brown color, with 4 finely striated and shouldered whorls separated by deep sutures. The spire is rounded and the large aperature is D-shaped.

Status and Rank

US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G2G3 - Rank is uncertain, ranging from imperiled to vulnerable
State Rank: SNR - Not ranked


CountyNumber of OccurrencesYear Last Observed
Charlevoix 5 2009

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.


The coldwater pondsnail most often occurs near open shorelines of lakes, including the Great Lakes (Burch 1988).

Natural Community Types

  • Great lake, littoral, benthic
  • Inland lake, littoral, benthic

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.

Management Recommendations

Management of the coldwater pondsnail should center around maintaining healthy habitat structure and water quality. River impoundments, dredging and channelization increase sedimentation, isolate existing populations and destroy necessary habitat. Such projects should address potential impacts to resident aquatic life through monitoring and mitigation measures. Chemical and heavy metal pollution from industrial waste, pesticides, agricultural/urban runoff, and other sources can be lethal to adult snails and prevent reproduction (Besser et al. 2007, Johnson 2009). Increasing water acidification can lead to freshwater snail communities being extirpated (Okland 1992). Reduction in the burning of fossil fuels will decrease the harmful effects of acid rain on this group.

Active Period

Active from first week of June to first week of October

Survey Methods

There are several effective methods for conducting aquatic snail surveys. Areas of coarse cobble substrate are best surveyed with a glass-bottomed bucket or scuba search, and hand collecting. Stones and sunken pieces of wood can be picked up, searched, and replaced. Dip net suveys are employed at soft substrate locations. Aquatic vegetation held over a bucket and vigorously shaken to remove individual snails is another technique (Groves 2007).

D-frame net, dip net

Survey Period: From first week of June to first week of October

Time of Day: Daytime

Glass-bottom bucket less than waist deep water

Survey Period: From first week of June to first week of October

Time of Day: Daytime

SCUBA greater than waist deep water

Survey Period: From first week of June to first week of October

Time of Day: Daytime

Shaking vegetation survey

Survey Period: From first week of June to first week of October

Time of Day: Daytime


Survey References

  • Groves, K. 2007. Aquatic Spring Snail Survey and Habitat Analysis. USDA Forest Service.

Technical References

  • Besser, J.M., D.L. Hardesty, I.E. Greer, C.A. Mebane, D.R. Mount, and C.G. Ingersoll. 2007. Sensitivity of freshwater snails to contaminants: chronic toxicity tests with endangered species and surrogates. U.S. Geological Survey.
  • Burch, J. 2004. Lymnaeidae. Pp 33-35. In: Perez, K.E., S.A. Clark and C. Lydeard (eds.). 2004. FMCS Showing Your Shells: A Primer to Freshwater Gastropod Identification. University of Alabama, Tuscaloosa, AL.
  • Burch, J.B. 1982. Freshwater Snails (Mollusca: Gastropoda) of North America. EPA Report 600/3-82-026. Environmental Monitoring and Support Laboratory, Office of Research and Development, Enviornmental Protection Agency, Cincinnati. 294 pp.
  • Burch, J.B. 1988. North American Freshwater Snails. Walkerana 2(6)
  • Johnson, P.D. 2009. Sustaining America's Aquatic Biodiversity: Freshwater Snail Biodiversity and Conservation. Virginia Cooperative Extension Publication 420-530.
  • Kosanke, G.J., W.W. Schwippert, and T.W. Beneke. 1988. The impairment of mobility and development in freshwater snails (Physa fontinalis and Lymnaea stagnalis) caused by herbicides. Comparative Biochemistry and Physiology Part C: Comparative Pharmacology 90(2):373-79.
  • Okland, J. 1992. Effects of acidic water on freshwater snails: results from a study of 1000 lakes throughout Norway. Environmental Pollution 78(1-3):127-30.