Lymnaeidae

Family

Lymnaeidae

Species

Radix auricularia (Linnaeus, 1758)

R. peregra (Muller, 1774)

Lymnaea stagnalis (Linnaeus, 1758)

Common Name

Radix auricularia: Big-ear Radix, Ear pond snail

R. peregra: Wandering pond snail

Lymnaea stagnalis: The great pond snail, Stagnant pond snail, Swamp lymnaea

Description

The shells of this freshwater-dwelling group are not patterned and they do not posses an operculum. They will attain a maximum height of 70 mm. The tentacles of these species are characteristically triangular in shape with the small eyes located at the base.

Radix auricularia: The big-ear Radix may be as large as 14-30 mm high and 12-25 mm wide, with 4-5 whorls. The whorls of this species rapidly increase towards the very large body whorl. The shell is slightly glossy and smooth. The thin shell of this species is generally tan to pale yellow. The aperture is ear-shaped and the umbilicus (navel) may be slightly open or closed altogether. The body of the animal may have small white spots on the head and tentacles.

R. peregra: The wandering snail is between 18-20 mm high and 12-13 mm wide. The shell of this species is tan to brown and may possess a blackish cover. The body of the animal is greenish with black and dirty-yellow spots covering it.

Lymnaea stagnalis: This species is very large when compared to the other 2 species in this group. It can attain a height of 45-70 mm and a width of 20-34 mm. The shell is also tan colored and does not have any obvious markings.

Distribution

Radix auricularia

North America:

U.S.: Massachusetts, New Jersey, New York, Nevada, Pennsylvania, Vermont

Europe: Croatia, Czech Republic, Germany, British Isles, Netherlands, Poland, Slovakia, Ireland (and possibly other countries)

Asia

R. peregra

North America:

U.S.: Massachusetts, New Jersey, New York, Pennsylvania, Vermont

Europe: Croatia, Czech Republic, Germany, British Isles, Netherlands, Poland, Slovakia, Ireland (and possibly other countries)

Asia

Lymnaea stagnalis

North America:

U.S.: Illinois, Massachusetts, Michigan, New Jersey, New York, Pennsylvania, Vermont, Wisconsin,

Europe: Croatia, Czech Republic, Germany, British Isles, Netherlands, Poland, Slovakia, Ireland (and possibly other countries)

Asia

Ecology

The species in this group prefers stagnant or very slow moving water with dense vegetation. R. auricularia is an intermediate host for a human pharyngeal parasite (Clinostomum complanatum).