Potamopyrgus jenkinsi, Hydrobia jenkinsi

Potamopyrgus antipodarum can survive passage through the guts of fish and may be transported by these animals (Bruce 2006). It can also float by itself or on mats of Cladophora spp., and move 60 m upstream in 3 months through positive rheotactic behavior (Zaranko et al. 1997). It can respond to chemical stimuli in the water, including the odor of predatory fish, which causes it to migrate to the undersides of rocks to avoid predation (Levri 1998). Common parasites of this snail include trematodes of the genus Microphallus (Dybdahl and Krist 2004).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic	Beneficial

Potamopyrgus antipodarum has a moderate environmental impact in the Great Lakes.

This species has a high reproductive capacity and a wide tolerance of abiotic conditions, increasing the potential for populations to grow and be widely-distributed (Alonso and Castro-Diez 2008). It is likely to find all shallower waters (<60 m depth) as suitable habitat (USEPA 2008). Potamopyrgus antipodarum has yet to colonize streams in the Great Lakes basin, but these are the habitats in which the snail is expected to exert significant impacts (Levri et al. 2007). Due to its ability to colonize empty spaces and habitats in early successional phases, P. antipodarum may also have greater invasion success in disturbed areas; however, its impacts are not limited to these types of systems (Alonso and Castro-Diez 2008).

Abundant populations of introduced P. antipodarum may outcompete other grazers for food resources and inhibit colonization by other macroinvertebrates and native snails (Kerans et al. 2005). Thus far, research efforts focused on interactions between P. antipodarum and native invertebrates have yielded mixed results, from commensalism to competition (Brenneis et al. 2010). 

Potamopyrgus antipodarum may have an impact on higher trophic levels of the food web. While P. antipodarum has been documented as a food source for Chinook salmon (Oncorhynchus tshawytscha; Bersine et al. 2008), brown trout (Salmo trutta; Vinson et al. 2007), and rainbow trout (Oncorhynchus mykiss), its lack of digestibility could be detrimental to its predators (Vinson and Baker 2008). Vinson and Baker (2008) found that 53.8% of New Zealand mudsnails passed through the digestive system of rainbow trout alive, with only 8.5% of snails estimated to have been fully digested. Furthermore, rainbow trout that were fed on a diet of P. antipodarum lost 0.14–0.48% of their initial weight per day. Unsuitability of P. anitopodarum as a food source and its potential competitive effects within lower trophic levels may affect food availability and alter food web processes in invaded systems (Kerans et al. 2005).

Potamopyrgus antipodarum is capable of serving as a host for a number of trematode parasites, although the extent of occurrence and consequences in its nonindigenous range is largely unknown (see Morley 2008).

There is little or no evidence to support that Potamopyrgus antipodarum has significant socioeconomic impact in the Great Lakes.
If P. antipodarum has adverse impacts on food web interactions in invaded ecosystems, it is possible that certain recreationally or commercially valuable species such as rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) could be negatively impacted at high snail densities (NZMWG 2007).

There is little or no evidence to support that Potamopyrgus antipodarum has significant beneficial effects  in the Great Lakes.

Partially due to their relatively high tolerance of environmental stressors, P. antipodarum is often used as a research organism to test novel experimental/analytical techniques (e.g., Myrick 2009, Schmitt et al. 2010a) or to test the physiological effects of toxic chemicals an aquatic fauna—particularly effects on the endocrine system (e.g., Alonso and Camargo 2009, Gust et al. 2009, Schmitt et al. 2010b).

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Many times NZ mudsnails may be in a river or lake where chemical eradication will not be feasible and physical eradication difficult. Areas where eradication may be possible include small lakes and ponds, waterbodies that can be temporarily hydrologically separated. 

Biological
Parasites of NZ mudsnails from New Zealand may also become useful to control population size by inhibiting reproduction. Studies of the efficacy and specificity of a trematode parasite from the native range of NZ mudsnails as a biological control agent have shown positive results so far (Dybdahl et al. 2005).

Physical
New Zealand mudsnails easily hitchhike with fish and aquatic plants.  Inspection of boats/trailers/gear is essential, but equipment should also be dried thoroughly before moving from infected to uninfected waters.  Putting fishing gear in a freezer for 6-8 hours will kill all attached New Zealand mudsnails (Medhurst 2003, Richards 2004). Putting fishing gear in water maintained at 120°F for a few minutes will eliminate New Zealand mudsnails (Medhurst 2003). The mudsnails can survive at 110°F so the water temperature needs to be accurate. Dry fishing gear at 84-86°F for at least 24 hours or at 104°F for at least two hours (Richards et al. 2004) - at lower temperatures snails can survive drying up to 53 hours (Geist et al. 2022).

For (aquaculture) facilities where no known New Zealand mudsnail contamination occurs, close visual inspection of water systems, raceways, stocking equipment, as well as regular gut content analysis can detect the arrival of snails before they can be spread.

Physical treatments include the use of temperature, humidity or desiccation to kill the target species. This includes draining the infested areas. New Zealand mudsnails can survive for long periods in a cool damp environment; however, draining the areas where they are congregated and exposing them to sunlight during the summer months may be sufficient for eradication. Using a flamethrower in a hatchery situation against the walls of raceways will kill any mudsnails attached. Mudsnails cannot withstand warm temperatures (Dwyer et al. 2003; Richards et al. 2004) or low humidity situations (Dwyer and Kerans, unpublished; Richards et al. 2004). Alternately, if an infested area could be drained in the winter and the substrate is frozen to a depth containing the mudsnails, then total eradication will occur. There is preliminary evidence that hydrocyclonic separators may also be a useful tool to decontaminate fish hatchery water supplies and prevent the spread of New Zealand mudsnails within a hatchery.

Chemical
Chemical methods used to eradicate New Zealand mudsnails (mostly in hatcheries) include: copper sulfate, niclosamide, Bayer 73, copper sulfate, 4-nitro-3-trifluoromethylphenol sodium salt (TFM), ammonia, benzalkonium chloride, benzethonium chloride, hyamine, hydrogen peroxide hydrothol, sodium chloride, and sodium hydroxide . Preliminary investigations also suggest that copper and carbon dioxide under pressure may prove useful in both decontaminating fish hatchery water supplies and preventing spread into uncontaminated areas of a hatchery. For equipment decontamination in the field, commercial products such as Formula 409, Pine-Sol, Rocca-D-Plus, and Virkon Aquatic have proven effective; bleach is considered ineffective. Elevated partial pressures of CO2 have been shown to be effective as a decontaminant and a feasible control method for disinfecting substrates and tank systems. Ozone has not been shown to be effective in killing New Zealand mudsnails in a hatchery environment. Many of the above products will kill fish, fish eggs and other sensitive species at the concentrations needed to kill P. antipodarum, potential non-target mortality should be given careful consideration for the particular system. (Geist et al. 2022, IJC 2011, De Stasio et al. 2019)

Other
It has been suggested that barriers such as copper stripping or electrical weirs may limit volitional movement of New Zealand mudsnails, particularly as a means of protecting high risk sites like fish hatchery water systems. Some investigations are underway but there is no applicable tool available yet.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.

The public should be careful to decontaminate fishing and sporting equipment so as not to spread existing populations or start new ones.  Regulations on commercial shipping of this species are in effect. The species supports a number of parasites in its native range, but none have been found on North American populations examined.

In 2020, Potamopyrgus antipodarum were found in the Bluewater State Fish Hatchery in Montana, near Blues Creek, a tributary to the Clarks Fork Yellowstone River; decontamination of the facility occurred after discovery. In 2022, the snails were discovered again, and another decontamination procedure, including fish destruction, occurred, with an estimated cost of $225,000 UDS (NBC Montana Staff 2022)