THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

Aquatic Invertebrates in Pacific Northwest Freshwater Wetlands
An Identification Guide and Educational Resource

Lymnaeids live in a wide variety of aquatic habitats. They are also commonly kept as aquarium pets, making them a likely candidate for introduction. They are pulmonate snails, i.e. they breathe air and lack an operculum.

Lymnaeidae can be quite large. Collected specimens tend to be damaged or immature, making identification difficult. The common introduced big eared radix (Radix auricularia) can be easily identified, however, by the large, flattened, wedge-shaped tantacles that give this snail its common name.

Lanx and Fisherola are members of Lymnaeidae (sometimes placed in the family Lancidae) and are discussed in the limpet section of this Guide.

Size: medium to large
Identifying feature(s): no operculum; shell is more cone-like and bulging; the shell opens to the right (dextral)
Habitat: most freshwater habitats
Tolerance: tolerant and sediment tolerant