NEMESIS Bioregion Distribution:


This species is a freshwater species with occurrences in tidal fresh or brackish waters and does not have a marine bioregion map associated with it. Please click on the Distribution Details tab for a North American distribution map. Additional information on this species and its distribution can be found in the USGS Nonindigenous Aquatic Species Database

First Non-native North American Marine/Estuarine Record: 1997
First Non-native West Coast Marine/Estuarine Record: 1997



General Invasion History:

Potamopyrgus antipodarum is native to fresh and brackish waters of the North and South Islands of New Zealand. In the 18th and 19th centuries, it was introduced to Australia (first reported 1870) and Europe (England- 1859) and spread rapidly in both continents (Winterbourn 1970; Ponder 1988). Possible vectors include dry ballast and the drinking water casks of sailing ships. In Europe, its range runs from the British Isles and Spain, east through the Baltic and Black Seas in interior fresh and coastal brackish waters (Nikolaev 1951; Ponder 1988; Leppakoski and Olenin 2000; Gomiou et al. 2002; Radea et al. 2008). Along the marine coasts of Europe, it prefers the fresher portions of estuaries but does tolerate salinities above 18 PSU (Gerard et al. 2003). This snail has also been introduced to Iraq (Naser and Son 2009) and Japan (Shimada and Urabe 2003).

The New Zealand Mud Snail has been transported by a wide range of vectors. While ships' drinking water barrels were a likely historical vector for introduction to Europe (Ponder 1988), subsequent dispersal modes probably included hull fouling on boats and ships, transport through canals, dry ballast, ballast water, transport on fishing gear, and with stocked fishes or ornamental aquatic plants (Eno et al. 1997; New Zealand Mudsnail Management and Control Plan Working Group 2007; Davidson et al. 2008). Natural dispersal on birds' feet and within guts is also likely (van Leeuwen 2012). The snail's small size, salinity tolerance, and parthenogenetic reproduction have enabled widespread transport (Alonso and Castro-Díez 2012). Multiple parthenogenetic clones exist in New Zealand and Australia, and many have been introduced. At least four clones have been introduced to North America, three probably directly from New Zealand. In the Great Lakes at least one clone arrived via Europe (Dybdahl and Drown 2011).

North American Invasion History:

Invasion History on the West Coast:

In 1987, Potamopyrgus antipodarum was first collected in North America in the headwaters of the Snake River, Idaho and subsequently spread to the headwaters of the Missouri River in Montana. At least three clones exist in Western North America, a widespread form (US 1) derived from New Zealand, and two with restricted ranges in the Snake River (US 1a and US3; Dybdahl and Drown 2011; Hershler et al. 2012). Its spread to other parts of North America has been rapid, but spotty, on boats, fishing gear, boots and waders, with stocked fish, etc. It was collected in the Columbia River estuary near Astoria in 1996 by James Carlton (personal communication, Davidson et al. 2008) and has subsequently spread into fresh and brackish waters up and down the West Coast, including the Rogue River, Oregon (OR) in 1999; Coos Bay, OR in 2005; Alsea Bay, OR in 2007; Yaquina Bay, OR in 2008; Tillamook Bay, OR in 2007; Long Beach, Washington (WA) in 2002; Willapa Bay tributaries, WA (Davidson et al. 2008); and Grays Harbor, WA (USGS Nonindigenous Aquatic Species Program 2013). In 2007, it was collected in Port Alberni Inlet, on the west side of Vancouver Island, British Columbia, at a salinity of 5 PSU (Davidson et al. 2008). By 2009, a population became established in Capitol Lake, Olympia, WA, an artificial lake created by damming an inlet of Puget Sound. An attempt was made to control the population by letting seawater flow into the lake at high tides, raising the salinity to 7.5-27 PSU. The backflush treatment greatly reduced P. antipodarum populations, but survivors showed increased salinity tolerances (Leclair and Cheng 2011).

In California, P. antipodarum was first collected in the Sacramento-San Joaquin Delta in 2003, on the Mokelumne River (USGS Nonindigenous Aquatic Species Program 2008). It has subsequently been collected in at least four other San Francisco Bay tributaries: Calaveras River (in 2004), Napa River, West Antioch Creek, and Alameda Creek (in 2008, USGS Nonindigenous Aquatic Species Program 2008). The New Zealand Mud Snail was also collected in other coastal watersheds from Ventura County to Santa Cruz (in 2008, USGS Nonindigenous Aquatic Species Program 2013).

Potamopyrgus antipodarum spread in a spotty fashion in the Intermountain West of North America, from the Snake River, Idaho in 1997, appearing in the Madison River, Montana-Wyoming in 1994-1995, and in the Green-Colorado system and the Great Salt Lake basin in Utah in 2001. It was found in the Colorado River in Arizona in 1996, and in southeastern California, in the Owens River Valley. In 2004-2005, populations were found in the South Platte River drainage, east of the Rockies in Colorado (USGS Nonindigenous Aquatic Species Program 2013; New Zealand Mudsnail Management and Control Plan Working Group 2007). This pattern of widely scattered dispersal suggests a diverse mixture of anthropogenic vectors, and possibly natural transport by birds, as well.

Invasion History on the East Coast:

In 1991, Potamopyrgus antipodarum was found at Wilson, New York on Lake Ontario (Zaranko et al. 1997). It spread in the Great Lakes - St. Lawrence system to Prescott, Ontario on the St. Lawrence River in 2004 (USGS Nonindigenous Aquatic Species Program 2013); Lake Erie in 2005; Thunder Bay, Ontario in 2005; the St. Louis River estuary, Minnesota in 2005; and Lake Michigan in 2006 (Trebitz et al. 2010; USGS Nonindigenous Aquatic Species Program 2013). The Great Lakes population belongs to a clone (US2) which has a mitochondrial DNA profile identical to the clone (EU A), which is widespread in Europe (Dybdahl and Drown 2011). This snail was probably transported to the Great Lakes in ballast water of transatlantic ships (Zaranko et al. 1997).

In 2013, it was found to be abundant in Spring Creek, in the Bald Eagle Creek (upper Susquehanna) watershed in central Pennsylvania (USGS Nonindigenous Aquatic Species Program 2013). This is its first occurrence in an Atlantic drainage outside the Great Lakes - St. Lawrence system. In September, 2017, P. antipodarum was found closer to Chesapeake Bay, in the Big Gunpowder River, about 50 km from tidal waters (Dance 2017). GARP modeling (Genetic Algorithm for Rule-set Production) predicts that this snail could colonize coastal drainages from Chesapeake Bay to Nova Scotia, and the Mississippi Basin to the edge of the Great Plains (Loo et al. 2007).

Invasion History elsewhere in the World:

Potamopyrgus antipodarum is likely introduced in Australia. It belongs to a genus that has several species in New Zealand, but has no fossil record and is the only Potamopyrgus species in Australia. It was first reported in Hobart, on the south coast of Tasmania, in 1872 (as Paludestrina wisemaniana and Bythinella legrandiana) and was subsequently found in Launcestown, Tasmania in 1879; and Melbourne, Victoria in 1895. It was first collected in Adelaide, South Australia in 1926 and near Sydney, New South Wales in 1963 (Ponder 1988). It is now widespread in coastal drainages of Victoria and also in streams around Adelaide and Sydney. It is predicted to be capable of colonizing most of the southeastern and some of the southwestern (Perth area) coastal region of Australia (Loo et al. 2007).

Potamopyrgus antipodarum was collected in Europe before it was found in Tasmania. It was found in the Thames estuary as early as 1859, and was formally named as Hydrobia jenkinsi Smith in 1889. It spread slowly in coastal areas at first and then rapidly along canals and coastal rivers. It was widespread by 1920 and now occurs from the Scilly Islands in the south, to the Shetland Islands in the north, although in Scotland it is largely confined to coastal areas (Ponder 1988; Eno et al. 1997). By 1887, this snail was collected in Germany in the Western Baltic Sea (Olenin and Leppakoski 2000), and within two decades was found in Copenhagen and the Oder-Odra lagoon (Gruszka 1999; Jensen and Knudsen 2005). The New Zealand Mudsnail spread further into the Baltic, reaching the mid-Baltic (Gotland, Sweden; Curonian Lagoon, Lithuania) by 1920, the Gulf of Finland by 1926, and the Gulf of Bothnia by 1945 (Nikolaev 1951; Leppakoski and Olenin 2000). It reached southern Norway by 1952 (Hopkins 2002), and was introduced to Galicia, Spain in the late 19th century, and Catalonia, on the Mediterranean by 1936 (Altimira 1969, cited by Múrria et al. 2008). Potamopyrgus antipodarum reached the Black Sea in Romania by 1952 (Gomoiu et al. 2002) and reached the region around Odessa, Ukraine by 2005 (Son 2008). The New Zealand Mud Snail has colonized the interior of Europe as well as the coast, reaching such landlocked countries as Switzerland and Austria (Alonso and Castro-Diez 2012).

Potamopyrgus antipodarum has had two widely separated introductions in Asia, in Japan and Iraq. It was first found in Japan, in Mie prefecture, Honshu in 1990, and is now found on all of Japan's main islands (National Institute for Environmental Studies 2013). In 2008, this snail was found in the Garmat Ali River, Basra, Iraq, part of Shat-al-Arab estuary (Naser and Son 2009). The authors consider bird dispersal to be the likeliest vector, but given the military and oil industry activity in the region, shipping cannot be ruled out.