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Protecting Northern Michigan's ​Water Resources

New Zealand Mudsnail

New Zealand mudsnails compete with other native species for food, disrupting the food chain and threaten the health and stability of aquatic ecosystems.

Scientific Name:

Potamopyrgus antipodarum

*Prohibited in Michigan

Identification:  A mature snail is usually less than 5 mm (.2 in) long. The shell is elongated and dextral (its whorls or spirals lean toward the right) and typically has between 5 to 6 whorls on its shell that are usually uniform in size. Most snails have a light to dark brown shell that may appear to be black when wet. The mudsnail operculum (a rounded plate that seals the mouth of the shell when the animal’s body is inside) can be seen on live snails but is not easily visible on dead or preserved snails.

Table of Contents

Credit: Washington Department of Fish & Wildlife
Credit: US Geological Survey
Photo by Mike Gangloff, Bugwood.org

Ecological Threat: 

  • New Zealand mudsnails compete with other native species for food, disrupting the food chain and threaten the health and stability of aquatic ecosystems.
  • Due to rapid self-reproduction, the species can quickly achieve densities of more than 500,000 snails per square meter.
  • They are a non-native species that have no natural predators, parasites, or diseases to control their population size in North America. 
  • They are hardy, adaptable animals that can inadvertently be transported by boats, fishing gear, and waders.

Be sure to thoroughly clean and dry equipment before transporting it to a new water body.

Think you have seen New Zealand mudsnails? 
If you find what you think are New Zealand mudsnails:

  • If the observation is within the Tip of the Mitt Watershed Council service area, please
    ​call (231) 347-1181 or email info@watershedcouncil.org

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Midwest Invasive Species Information Network (MISIN)

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