New Zealand Mudsnail

Potamopyrgus antipodarum


  • Very small (3-6 mm long) aquatic snail native to New Zealand
  • Elongated, cone shaped shell is light–dark brown and consists of 5–6 right-handed whorls
  • Colonizes a wide range of habitats including rivers, lakes, streams, estuaries, reservoirs, lagoons, canals, ditches, and even water tanks; thrives in disturbed watersheds
  • Can withstand moderate desiccation and drought for several days facilitating survival during overland transport of watercraft

Consequences of invasion

  • High reproductive rates and an ability to avoid predation enable establishment of very dense populations
  • Competes with and displaces native invertebrates
  • Alters aquatic ecosystem dynamics
  • Threatens fisheries in locations where it has established
  • Can clog water pipes and irrigation systems
  • Reproduce rapidly by asexual means so a single individual can be sufficient to create a new population

Integrated pest management options

  • Once established, eradication is improbable in most locations
  • Spread to new locations is the result of human activity so Clean, Drain, and Dry watercraft and associated equipment, including waders, before entering into another body of water

Additional resources