Plants and Animals

Stagnicola petoskeyensis Petoskey pondsnail

Key Characteristics

The Petoskey pondsnail is a large, freshwater snail with a narrowly conic shell that is 1.5 to 2.5 cm in height and 1.2 cm wide with a long, pointed spire and the dextral whorls (i.e., curving clockwise when the spire is pointed upwards). It is sculptured with thick revolving growth lines.

Status and Rank

US Status:
State Status: E - Endangered (legally protected)
Global Rank: GH
State Rank: SH - Possibly extirpated

Occurrences

CountyNumber of OccurrencesYear Last Observed
Emmet11908

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.

Habitat

The only known site in the world was from a small calcareous spring-fed stream.

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.

Management Recommendations

Very little is known about this presumed historical species. Management that protects stream hydrology, avoids siltation and prevents pollution while maintaining a natural vegetation buffer would likely be beneficial.

Active Period

Active from first week of June to first week of October

Survey Methods

This species can be surveyed using several techniques. One survey method consists of sweeping aquatic vegetation or scraping the substrate with a fine mesh aquatic sampling net or dip net (e.g., D-frame net). Another survey technique consists of vigorously shaking aquatic vegetation over a pail of water causing the various snails clinging to the plants to drop to the bottom of the pail. Visual surveys also can be conducted for this species by looking for snails attached to vegetation, rocks, woody debris and other cover. Glass bottomed buckets may be used to see snails clinging to vegetation or rocks underwater. Rocks, vegetation, and other cover also should be picked up, examined for snails, and returned to their original positions.

Sweep with dip net

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

Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity

Shaking vegetation survey

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

Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity

Visual survey

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

Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity

References

Survey References

  • Berry, E.G. 1943. The Amnicolidae of Michigan: Distribution, Ecology, and Taxonomy. University of Michigan Press, Ann Arbor. 68pp.
  • Clarke, A.H. 1981. The Freshwater Molluscs of Canada. National Museum of Natural Science, National Museums of Canada, Ottawa. 446pp.

Technical References

  • Burch, J.B. and Y. Jung. 1992. Freshwater snails of the University of Michigan Biological Station area. Walkerana 6(15).
  • Dillon, R.T. Jr. 2000. The Ecology of Freshwater Molluscs. Cambridge University Press, Cambridge, UK. 509pp.
  • Environmental Protection Agency. 1982. Freshwater Snails (Mollusca: Gastropoda) of North America. EPA Publication 600/3-82-026. Environmental Monitoring and Support Laboratory, Office of Research and Development, U.S. EPA, Cincinnati. 294pp.