Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Guide to New Zealand's freshwater invertebrates

Snail ( Lymnaeidae : Pseudosuccinea )

Diagnostic features

Pseudosuccinea is one of the introduced lymnaeid snails now common in many parts of New Zealand. The lymnaeids lack an operculum (protective shield) that covers the aperture (shell opening) when the animal withdraws. The aperture is on the right when facing toward you and when the spire points upwards. Pseudosuccinea has an elongated body whorl and a thin shell with distinct surface ribbing.

Typical habitats

Pseudosuccinea columella is found in many slow flowing streams, including some geothermally heated streams.


Like most snails they are grazers, scraping biofilms from submerged surfaces.

Indicator value

Pseudosuccinea can be found in many degraded habitats including urban streams with relatively poor water quality. This genus has not been assigned tolerance values but the Lymnaeidae have low tolerance values of 3 (hard bottom sites) and 1.2 (soft bottom sites).