Montana Field Guide

Amnicola is a genus of very small freshwater snails (generally <0.5 inch tall) that have an operculum which can seal the interior soft tissues of the shell from the environment. The shells are globose and typically about as wide as they are tall. Length is typically only a few millimeters (mm). They can be fairly tolerant of warm water and low oxygen conditions. Generally shell color is tan to light brown.

Generally shell color is tan to light brown. Not many other dextral snails with operculum are this light color.

Sedentary, not known to migrate.

Freshwater. Populations are typically found in lentic environments, but can be commonly collected in slow-moving rivers, often on woody debris.

Amnicola populations appear to be grazers of diatoms and other periphyton (Kesler 1981 and Cattaneo and Kalff 1986). They in turn they are preyed upon by crayfish (Lewis 2001) and sunfish (Osenberg 1989 and Bronmark et al. 1992)

Populations are typically found in lentic environments, but can be commonly collected in the slow-moving rivers, often on woody debris. In Montana, outside of stream collections, we found them in the prairie region spring-fed pools on woody debris.