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Jenkins' Spire Snail, New Zealand Mudsnail
Potamopyrgus antipodarum

Last edited: October 4th 2019

Jenkins' Spire Snail, New Zealand Mudsnail - Potamopyrgus antipodarum

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Short description of Potamopyrgus antipodarum, Jenkins' Spire Snail, New Zealand Mudsnail

This snail of right‐handed coiling has an elongated shell with 7 to 8 whorls. Size is usually around 5 mm but can reach about 12 mm. Shell colours vary from grey and dark brown to light brown.

Impact summary: Potamopyrgus antipodarum, Jenkins' Spire Snail, New Zealand Mudsnail

It can produce very dense populations that can displace native invertebrates and alter ecosystem dynamics.

Habitat summary: Potamopyrgus antipodarum, Jenkins' Spire Snail, New Zealand Mudsnail

It is an extremely tolerant species inhabiting almost all aquatic habitats including rivers, lakes, streams, estuaries, reservoirs, lagoons, canals, ditches and even water tanks. Particularly high densities are reported from systems with high primary productivity, constant temperatures, cobble substrate and constant flow.

Overview table

Environment Freshwater
Species status Non-Native
Native range New Zealand
Functional type Herbivore
Status in England Non-Native
Status in Scotland Non-Native
Status in Wales Non-Native
Location of first record Grays (18); Thames Estuary (VIIc)
Date of first record 1852


It is native to freshwater streams and lakes of New Zealand and adjacent small islands.

First Record

1852 in the Thames estuary, England (as Hydrobia jenkinsi).

Pathway and Method

It was introduced in drinking water barrels in ships from Australia. The snails were probably liberated while washing or filling water barrels or tanks and, because they can survive in brackish water, they could probably survive liberation into estuarine areas such as the River Thames.

Species Status

This New Zealand species was first introduced into Australia, from where it was brought to GB in the mid 19th century. Its initial rate of spread around the British coast was moderate, but once it started colonising freshwater habitats around 1904, it spread very rapidly until, by 1920, it was very widespread in GB. It is now one of the commonest aquatic snails in GB and is still extending its distribution into even the most remote parts of Scotland. It first reached the European mainland by about 1900, where it is now common and widespread. More recently, i.e. in the early 1990s, it was first documented in North America and has quickly colonised a range of freshwater systems.

Dispersal Mechanisms

This tiny snail may be dispersed by a range of natural vectors including birds, fish and water currents on floating macrophytes. As it is able to withstand desiccation and a variety of temperature regimes, humans can inadvertently be the mechanism for transfer to new water bodies. Commercial movement of aquaculture products, e.g. live fish or eggs, may also be important vectors. The most important method of long distance dispersal is through ship ballast water.


While in its native range, it reproduces both sexually and asexually, non-native populations are exclusively parthenogenetic and consist almost exclusively of clonal individuals. One specimen may be enough to start a new invasion and produces about 230 juveniles per year. In favourable conditions, it may reproduce year-round.

Known Predators/Herbivores

Fish, birds and invertebrate organisms (e.g. non-native flatworm Planaria torva).

Resistant Stages

It can withstand moderate desiccation and drought for several days.

Habitat Occupied in GB

Inhabiting estuaries, standing and flowing freshwaters. The snail tolerates siltation, thrives in disturbed watersheds, and benefits from high nutrient flows allowing for filamentous green algae growth. It occurs amongst macrophytes and prefers littoral zones in lakes or slow streams with silt and organic matter substrates, but tolerates high flow environments where it can burrow into the sediment.

Common and widespread across England, Wales, some parts of Scotland, the Channel Islands and Northern Ireland. Also established in most European countries including Scandinavia and the Baltic Sea. Also present in several parts of Asia (e.g. Iraq, Russian Federation, Turkey and Japan), North America (USA, Canada) and Australia.

Environmental Impact

May establish very dense populations (several 100,000 snails/m2), and can dominate gastropod communities (e.g. >80% of gastropods at Mont Saint-Michael Bay, France and a Polish reservoir, respectively). Consequently, it can consume large amounts of primary production, alter ecosystem dynamics, compete with and displace native invertebrates, and negatively influence higher trophic levels. Its ecological plasticity, high competitive ability, high reproductive rate, high capacity for various dispersal methods, and ability to avoid predation make it a formidable coloniser capable of establishing abundant populations with significant effects on ecosystems.

Health and Social Impact

None known.

Economic Impact

In the early 1900s it was responsible for blocking part of London's water supply, but the use of filters have overcome this problem.


Ellis, A.E. (1962) British Freshwater Bivalve Mollusca. Synopses of the British Fauna, 13, 1-92.

Biology, ecology, spread, vectors

Alonso, A. & Castro-Diez, P. (2008) What explains the invading success of the aquatic mud snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca)? Hydrobiologia, 614, 107-116.

Kerney, M.P. (1999) Atlas of the land and freshwater molluscs of Britain and Ireland. Harley Books.

Loo, S.E., Mac Nally, R. & Lake, P.S. (2007) Forecasting New Zealand mudsnail invasion range: Model comparisons using native and invaded ranges. Ecological Applications, 17, 181-189.

Ponder, W.F. (1988) Potamopyrgus antipodarum - A Molluscan coloniser of Europe and Australia. Journal of Molluscan Studies, 54, 271-285.

Schreiber, E.S.G., Quinn, G.P. & Lake, P.S. (2003) Distribution of an alien aquatic snail in relation to flow variability, human activities and water quality. Freshwater Biology, 48, 951–961.

Smith, E.A. (1889) Notes on British Hydrobidae with a description of a supposed new species. Journal of Conchology, 6, 142-145.

Wallace, C. (1985) On the distribution of the sexes of Potamopyrgus jenkinsi (Smith). Journal of Molluscan Studies, 51, 290-296.

Management and impact

Hall, R.O.J., Tank, J.L. & Dybdahl, M.F. (2003) Exotic snails dominate nitrogen and carbon cycling in a highly productive stream. Frontiers in Ecology and the Environment, 1, 407–411.

Strzelec, M. (2005) Impact of the introduced Potamopyrgus antipodarum (Gastropoda) on the snail fauna in post-industrial ponds in Poland. Biologia (Bratislava), 60, 159-163.


Richards, D., Kerans, B. & Gustafson, D. (2007) New Zealand Mudsnails in the Western USA. Available at http://www.esg.montana.edu/aim/mollusca/nzms/.