Snail (New Zealand mudsnail) Potamopyrgus antipodarum
Genus: Potamopyrgus (genus of native snails)
Species: P. antipodarum
Binominal name: Potamopyrgus antipodarum
Synonyms: Potamopyrgus jenkinsi, Amnicola antipodanum
Common names: New Zealand mudsnail, Mud snail, Jenkin’s spire-snail.
Potamopyrgus antipodarum is very small or minute freshwater snail, an aquatic gastropod mollusk and is endemic to New Zealand.
Potamopyrgus antipodarum are found in most New Zealand streams, rivers and lakes. They are found in pristine and polluted waters. Potamopyrgus estuarinus is the other snail in the same genus and is restricted to sites with tidal influence.
Potamopyrgus antipodarum are grey to dark brown to light brown in colour. They have an obvious spire, with a gill and an operculum (gill cover) covering the oval aperture (shell opening) when the animal withdraws. Sometimes there are nodules around the shell. The aperture is on the right when facing toward you and when the spire points upwards.
Like most snails they are grazers, scraping biofilms from submerged surfaces.
Potamopyrgus antipodarum is an invasive species in many countries, where populations of the snail can reach phenomenal densities.