Fossaria galbana
Boreal fossaria

Key Characteristics

The boreal fossaria is a small (to .4 inches in length), ovately conic, thick-shelled freshwater snail of a glossy white to tan color. The aperature is oval with a sharp lip and the 5-6 deeply sutured and finely striated whorls end at a somewhat pointed spire.

Status and Rank

  • State Status: SC
  • State Rank: SNR
  • Global Rank: G5Q


County NameNumber of OccurrencesYear Last Observed
Distribution map for Fossaria galbana

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.


Requiring cold, highly oxygenated water, the boreal fossaria can be found in large rivers and medium to large lakes among abundant aquatic vegetation (Burch and Jung 1992).

Specific Habitat Needs

Aquatic vegetation needed in 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.


As this species requires highly oxygenated aquatic habitats, high water quality should be maintained. Efforts should be made to reduce agricultural and urban stormwater runoff, wastewater treatment discharge, and other forms of point and non-point source pollution known to cause low dissolved oxygen conditions. Pesticide/insecticide spraying should be kept to a minimum in areas inhabited by vulnerable snail species, as reproductive success rates significantly decline with exposure to the chemicals and heavy metals contained in many products (Besser et al. 2007, Kosanke et al. 1988). Major projects which alter aquatic habitats such as dredging, channelization, and impoundment should plan monitoring and mitigation measures to account for impacts on resident mollusks.

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).

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at [Accessed Sep 22, 2018]


Survey References

Technical References

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