> Amnicola limosa (Say 1817)

> Habitat & Distribution
Amnicola limosa is widespread throughout eastern North America, from Canada to Florida, ranging at least as far west as Utah (Berry 1943).  Populations are typically found in lentic environments.  In Atlantic drainages of the southeastern United States, A. limosa is most commonly collected in the slow-moving rivers and swamps of the coastal plain, often on woody debris.  Such waters are often darkened by high concentrations of organic compounds, but are not necessarily acidic.

> Ecology & Life history
Several excellent studies have been directed toward the biology of A. limosa populations inhabiting northern lakes and ponds.  Amnicola populations appear to be efficient grazers of diatoms and other periphyton (Kesler 1981, Cattaneo & Kalff 1986).  They in turn may be eaten by crayfish (Lewis 2001) and sunfish (Osenberg 1989, Bronmark et al 1992)

Populations generally appear to be annual and semelparous (cycle A of Dillon 2000: 156 – 162).  But dynamics appear to be sensitive to aspects of water chemistry, especially hardness and pH (Shaw & Mackie 1989, 1990). 

> Taxonomy & Systematics
By comparison to other hydrobiid taxa, systematic relationships have remained relatively stable in the genus Amnicola (Berry 1943, Hershler & Thompson 1988).  Amnicola limosa may be confused with several other local hydrobiid taxa of equally vanilla shell morphology.  The essay referenced below contains a link to a comparative photo that may be helpful in this regard. 

> Essay
My 26May04 essay on Somatogyrus also included notes on Amnicola and a couple photos.

> Maps of Amnicola distribution
Click the small map to enlarge it, or download the state-specific PDFs



North Carolina (PDF)

South Carolina (PDF)

Georgia (PDF)

> References
Berry, E. (1943) The Amnicolidae of Michigan: Distribution, ecology, and taxonomy. Misc. Publ. Mus. Zool. U. Mich., 57, 1-68.  Bronmark, C., Klosiewski, S. & Stein, R. (1992)  Indirect effects of predation in a freshwater, benthic food chain.  Ecology 73: 1662 – 1674.  Hershler, R. & Thompson, F.G. (1988)  Notes on morphology of Amnicola limosa (Say, 1817) (Gastropoda: Hydrobiidae) with comments on status of the subfamily Amnicolinae.  Malacol. Rev. 21: 81-92.  Horst, T.J. & Costa, R.R. (1975) Seasonal migration and density patterns of the fresh water snail Amnicola limosa.  Nautilus 89: 56-59.  Kesler, D.H. ( 1980)  Seasonal abundance of Amnicola limosa (Hydrobiidae) eggs and individuals in a Rhode Island Pond.  Nautilus 94: 25-26.  Kesler, D.H. (1981)  Periphyton grazing by Amnicola limosa: An enclosure-exclosure experiment.  J. Freshwat. Ecol. 1: 51-59.  Kesler, D. H. & Tulou, C. A. G. (1980)  Cellulase activity in the freshwater gastropod Amnicola limosa.  Nautilus 94: 135-137.  Lewis, D. B. (2001)  Trade-offs between growth and survival: Responses of freshwater snails to predacious crayfish.  Ecology 82: 758-765.  Lewis, D. B. & Magnuson, J.J. (1999)  Intraspecific gastropod shell strength variation among north temperate lakes.  Can. J. Fish. Aquat. Sci. 56: 1687-1695. 1999.  Mackie, G.L. & Flippance, L.A. (1983)  Relationships between buffering capacity of water and the size and calcium content of freshwater mollusks.  Freshwat. Invertebr. Biol. 2: 48-55.  Osenberg, C. (1989)  Resource limitation, competition and the influence of life history in a freshwater snail community.  Oecologia 79: 512 – 519.  Pinel-Alloul, B. (1973)  (Observations on the life cycle and growth of Amnicola limosa (Say)(Mollusca, Prosobranchia) from Lake St-Louis, Near Montreal).  Can. J. Zool. 51: 311-313.  Shaw, M. A. & Mackie, G.L. (1990)  Effects of calcium and pH on the reproductive success of Amnicola limosa (Gastropoda).  Can. J. Fish. Aquat. Sci. 47: 1694-1699.  Shaw, M.A. & Mackie, G.L. (1989)  Reproductive success of Amnicola limosa (Gastropoda) in low alkalinity lakes in south-central Ontario.  Can. J. Fish. Aquat. Sci. 46: 863-869.