> Ferrissia rivularis (Say 1817)

> Habitat & Distribution
F. rivularis ranges throughout North America, inhabiting rocky riffles.  It seems to require well-oxygenated water, and is especially characteristic of low-nutrient streams with good water quality.  In the southern Atlantic drainage it is almost completely restricted to the Blue Ridge and Piedmont ecoregions.

> Ecology & Life history
This little limpet was one of the most herbivorous of the macrobenthos studied by Coffmann (1971) dining almost entirely upon diatoms.  It shows great variation in life cycle, Burky (1971) reporting a simple annual life cycle in one population and two generations per year in a second.  Although I would not have been surprised to see evidence of Stress adaptation in the bioenergetics of F. rivularis, both of Burky’s populations posted reproductive efforts in line with their adult sizes, suggesting that they are Undifferentiated in their life history strategy (Dillon 2000: 126 - 135).  

> Taxonomy & Systematics
The North American Ancylidae has been fairly stable since the treatment of Basch (1963).

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



North Carolina (PDF)

South Carolina (PDF)

Georgia (PDF)

> References
Basch, P. (1963)  A review of the recent freshwater limpet snails of North America. Bull. Mus. Comp. Zool. Harvard, 129, 399-461.  Burky, A. (1971)  Biomass turnover, respiration, and interpopulation variation in the stream limpet Ferrissia rivularis (Say). Ecol. Monog., 41: 235-251.  Coffman, W. (1971)  Energy flow in a woodland stream ecosystem: I. Tissue support trophic structure of the autumnal community. Arch. Hydrobiol., 68: 232-276.  Dillon, R. T., Jr. (2000)  The Ecology of Freshwater Molluscs.  Cambridge University Press, United Kingdom.  509 pp.  Hubendick, B. (1964) Studies on Ancylidae, The subgroups.  Meddelanden Fran Goteborgs Musei Zoologiska Avendelining, 137.  (Goteborgs Kungl. Vetenskaps-Och Vitterhets-Samhalles Handlingar.  Sjatte Foljden. Ser. B.) 9, 1-72  Keating, S.T. & Prezant, R.S. (1998)  Effects of stream chemistry on the distribution, growth, and diatom colonization of the freshwater limpet, Ferrissia rivularis.  J. Freshwat. Ecol. 13: 67-77.  Russell-Hunter, W.D., M. L. Apley, A. J. Burky, & R. T. Meadows (1967)  Interpopulation variations in calcium metabolism in the stream limpet, Ferrissia rivularis (Say)  Science 155: 338-340.  Russell-Hunter, W.D., Burky, A.J. & Russell-Hunter, R.D. (1981)  Interpopulaton Variation in Calcareous and Proteinaceous Shell Components in the Stream Limpet, Ferrissia rivularis.  Malacologia 20: 255-266.