New Zealand mud snail

The New Zealand mud snail (Potamopyrgus antipodarum) is a species of very small freshwater snail with a gill and an operculum. This aquatic gastropod mollusk is in the family Tateidae.

This article is about the invasive mudsnail Potamopyrgus antipodarum. For another mud snail from New Zealand, see Amphibola crenata.

New Zealand mudsnail
right side view of Potamopyrgus antipodarum

Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Clade: Caenogastropoda
Clade: Hypsogastropoda
Order: Littorinimorpha
Family: Tateidae
Genus: Potamopyrgus
Species:
P. antipodarum
Binomial name
Potamopyrgus antipodarum
Synonyms
  • Amnicola antipodanum J. E. Gray, 1843
  • Amnicola corolla Gould, 1847
  • Hydrobia jenkinsi E. A. Smith, 1889
  • Paludestrina jenkinsi (E. A. Smith, 1889)
  • Potamopyrgus jenkinsi (E. A. Smith, 1889)
  • Potamopyrgus jenkinsi aculeata Overton, 1905
  • Rissoa vana Hutton, 1873
  • Rissoina fuscozona Suter, 1908
  • Rissoina vana (Hutton, 1873)

It is native to New Zealand, where it is found throughout the country,[3] but it has been introduced to many other countries, where it is often considered an invasive species because populations of the snail can reach phenomenal densities.

Shell description
Shells of Potamopyrgus antipodarum f. carinata (left)
and Potamopyrgus antipodarum (right).
Scale bar is 0.5 cm.
A group of mudsnails of all growth sizes from juvenile to adults, compared to an American 10 cent coin, which is 18 mm in diameter.

The shell of Potamopyrgus antipodarum is elongated and has dextral coiling, with 7 to 8 whorls. Between whorls are deep grooves. Shell colors vary from gray and dark brown to light brown. The average height of the shell is approximately 5 mm ( in); maximum size is approximately 12 mm ( in). The snail is usually 4–6 mm in length in the Great Lakes, but grows to 12 mm in its native range.[4][5][6] It is an operculate snail, with a 'lid' that can seal the opening of its shell. The operculum is thin and corneus with an off-centre nucleus from which paucispiral markings (with few coils) radiate. The aperture is oval and its height is less than the height of the spire. Some morphs, including many from the Great Lakes, exhibit a keel in the middle of each whorl; others, excluding those from the Great Lakes, exhibit periostracal ornamentation such as spines for anti–predator defense.[4][7][5][6]

Taxonomy

This species was originally described as Amnicola antipodarum in 1843 by John Edward Gray:

Inhabits New Zealand, in fresh water. Shell ovate, acute, subperforated (generally covered with a brown earthy coat); whorls rather rounded, mouth ovate, axis 3 lines; operculum horny and subspiral: variety, spire rather longer, whorls more rounded. This species is like Paludina nigra of Quoy and Gaimard, but the operculum is more spiral. Quoy described the operculum as concentric, but figured it subspiral. Paludina ventricosa of Quoy is evidently a Nematura.[2]

Forms
  • Potamopyrgus antipodarum f. carinata (J. T. Marshall, 1889)

Distribution

This species was originally endemic to New Zealand where it lives in freshwater streams and lakes in New Zealand and adjacent small islands.[8]

It has now spread widely and has become naturalised, and an invasive species in many areas including: Europe (since 1859 in England), Australia, Tasmania, Asia (Japan,[9] in Garmat Ali River in Iraq since 2008[10]), and North America (USA and Canada: Thunder Bay in Ontario since 2001, Washington State since 2002,[11] British Columbia since July 2007[9]), most likely due to inadvertent human intervention.

Invasion in Europe

Since being found in Ireland as early as 1837, Potamopyrgus antipodarum has now spread to nearly the whole of Europe. It is considered as about the 42nd worst alien species in Europe and the second worst alien gastropod in Europe.[12]

It does not occur in Iceland, Albania, Bulgaria or the former Yugoslavia.[13]

Countries where it is found include:

Distribution within the United States
Distribution of Potamopyrgus antipodarum within the USA in 2009.

First detected in the United States in Idaho's Snake River in 1987, the mudsnail has since spread to the Madison River, Firehole River, and other watercourses around Yellowstone National Park; samples have been discovered throughout the western United States.[6] Although the exact means of transmission is unknown, it is likely that it was introduced in water transferred with live game fish and has been spread by ship ballast or contaminated recreational equipment such as wading gear.[20]

The New Zealand mudsnail has no natural predators or parasites in the United States, and consequently has become an invasive species. Densities have reached greater than 300,000 individuals per m² in the Madison River. It can reach concentrations greater than 500,000 per m², endangering the food chain by outcompeting native snails and water insects for food, leading to sharp declines in native populations.[21] Fish populations then suffer because the native snails and insects are their main food source.

Mudsnails are impressively resilient. A snail can live for 24 hours without water. They can however survive for up to 50 days on a damp surface,[22] giving them ample time to be transferred from one body of water to another on fishing gear. The snails may even survive passing through the digestive systems of fish and birds.[23]

Mudsnails have now spread from Idaho to most western states of the U.S., including Wyoming, California, Nevada, Oregon, Montana, and Colorado. Environmental officials for these states have attempted to slow the spread of the snail by advising the public to keep an eye out for the snails, and bleach or heat any gear which may contain mudsnails. Rivers have also been temporarily closed to fishing to avoid anglers spreading the snails.[24][25]

The snails grow to a smaller size in the U.S. than in their native habitat, reaching 6 mm (¼ in) at most in parts of Idaho, but can be much smaller making them easy to overlook when cleaning fishing gear.

Clonal species like the New Zealand mudsnail can often develop clonal lines with quite diverse appearances, called morphs. Until 2005, all the snails found in the western states of the U.S. were believed to be from a single line. However a second morph has been identified in Idaho's Snake River. It grows to a similar size but has a distinctive appearance. (It has been nicknamed the salt-and-pepper mudsnail due to the final whorl being lighter than the rest of the shell.) This morph has apparently been present in the area for several years before being identified correctly as a distinct morph of Potamopyrgus antipodarum. It dominates the typical morph where they overlap, and has a much higher prevalence of males.[26]

In 1991, the New Zealand mudsnail was discovered in Lake Ontario,[27] and has now been found in four of the five Great Lakes. In 2005 and 2006, it was found to be widespread in Lake Erie.[28] By 2006 it had spread to Duluth-Superior Harbour and the freshwater estuary of the Saint Louis River.[29] It was found to be inhabiting Lake Michigan, after scientists took water samples in early summer of 2008.[30] The snails in the Great Lakes represent a different line from those found in western states, and were probably introduced indirectly through Europe.[26]

In 2002, the New Zealand mudsnail was discovered in the Columbia River Estuary. In 2009, the species was discovered in Capitol Lake in Olympia, Washington. The lake has been closed to all public use, including boating and other recreation, since 2009.[31] A heavy cold snap in 2013, combined with a drawdown in water level in preparation, was roughly estimated to have killed 40–60% of the mudsnail population.[32][33] Other known locations include the Long Beach peninsula, Kelsey Creek (King County), Thornton Creek (King County), and Lake Washington.

In 2010, the Los Angeles Times reported that the New Zealand mudsnail had infested watersheds in the Santa Monica Mountains, posing serious threats to native species and complicating efforts to improve stream-water quality for the endangered Southern California Distinct Population Segment of steelhead.[34] According to the article, the snails have expanded "from the first confirmed sample in Medea Creek in Agoura Hills to nearly 30 other stream sites in four years." Researchers at the Santa Monica Bay Restoration Commission believe that the snails' expansion may have been expedited after the mollusks traveled from stream to stream on the gear of contractors and volunteers.[35]

As of 21 September 2010 In Colorado, Boulder Creek and Dry Creek have infestations of New Zealand mudsnails. The snails have been present in Boulder Creek since 2004 and were discovered in Dry Creek in September 2010. Access to both creeks has been closed to help avoid spread of the snails. In the summer of 2015 an industrial-scale wetland rehabilitation project was undertaken in northeast Boulder to rid the area of a mud snail infestation.

Ecology

Habitat

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.[4][6][36][37][38][39][40][41][42][43][44]

In the Great Lakes, the snail reaches densities as high as 5,600 per m² and is found at depths of 4–45 m on a silt and sand substrate.[4][5][6]

This species is euryhaline, establishing populations in fresh and brackish water. The optimal salinity is probably near or below 5 ppt, but Potamopyrgus antipodarum is capable of feeding, growing, and reproducing at salinities of 0–15 ppt and can tolerate 30–35 ppt for short periods of time.[4][6][45][46][47][48]

It tolerates temperatures of 0–34 °C.[4][6][49]

Feeding habits

Potamopyrgus antipodarum is a nocturnal grazer-scraper, feeding on plant and animal detritus, epiphytic and periphytic algae, sediments and diatoms.[4][6][50][51][52][53]

Life cycle

Potamopyrgus antipodarum is ovoviviparous and parthenogenic. This means that they can reproduce asexually; females "are born with developing embryos in their reproductive system." Native populations in New Zealand consist of diploid sexual and triploid parthenogenically cloned females, as well as sexually functional males (less than 5% of the total population). All introduced populations in North America are clonal, consisting of genetically identical females.[6]

As the snails can reproduce both sexually and asexually, the snail has been used as a model organism for studying the costs and benefits of sexual reproduction. Asexual reproduction allows all members of a population to produce offspring and avoids the costs involved in finding mates. However, asexual offspring are clonal, so lack variation. This makes them susceptible to parasites, as the entire clonal population has the same resistance mechanisms. Once a strain of parasite has overcome these mechanisms, it is able to infect any member of the population. Sexual reproduction mixes up resistance genes through crossing over and the random assortment of gametes in meiosis, meaning the members of a sexual population will all have subtly different combinations of resistance genes. This variation in resistance genes means no one parasite strain is able to sweep through the whole population. New Zealand mudsnails are commonly infected with trematode parasites, which are particularly abundant in shallow water, but scarce in deeper water. As predicted, sexual reproduction dominates in shallow water, due to its advantages in parasite resistance. Asexual reproduction is dominant in the deeper water of lakes, as the scarcity of parasites means that the advantages of resistance are outweighed by the costs of sexual reproduction.[54]

Each female can produce between 20 and 120 embryos.[20] The snail produces approximately 230 young per year. Reproduction occurs in spring and summer, and the life cycle is annual.[4][6][8][48][55][56] The rapid reproduction rate of the snail has caused the numbers of individuals to increase rapidly in new environments. The highest concentration of New Zealand mudsnails ever reported was in Lake Zurich, Switzerland, where the species colonized the entire lake within seven years to a density of 800,000 per m².[6][57]

Parasites

The parasites of this species include at least 11 species of Trematoda.[6][58] Common parasites of this snail include trematodes of the genus Microphallus.[6][59][60]

In their native habitat, these parasites sterilize many snails, keeping the populations to a manageable size. However, elsewhere in the world in the absence of these parasites, they have become an invasive pest species.[6]

Other interspecific relationship

Potamopyrgus antipodarum can survive passage through the guts of fish and birds and may be transported by these animals.[23]

It can also float by itself or on mats of Cladophora spp., and move 60 m upstream in 3 months through positive rheotactic behavior.[4] 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.[6][61]

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See also

References
  1. Van Damme, D. (2013). "Potamopyrgus antipodarum". IUCN Red List of Threatened Species. 2013: e.T155980A738398. doi:10.2305/IUCN.UK.2013-2.RLTS.T155980A738398.en.
  2. Dieffenbach, E. 1843. Travels in New Zealand; with contributions to the geography, geology, botany, and natural history of that country. In two volumes - Vol. II. - pp. i-iv [= 1-4], 1-396, pl. [1]. London. (Murray), page 241.
  3. "Potamopyrgus antipodarum (Gray in Dieffenbach, 1843)". Retrieved 14 July 2019.
  4. Zaranko, D. T., D. G. Farara and F. G. Thompson. 1997. Another exotic mollusk in the Laurentian Great Lakes: the New Zealand native Potamopyrgus antipodarum (Gray 1843) (Gastropoda, Hydrobiidae).
  5. Levri, E.P., A.A. Kelly and E. Love. 2007. The invasive New Zealand mud snail (Potamopyrgus antipodarum) in Lake Erie. Journal of Great Lakes Research 33: 1–6.
  6. Benson, A.J.; Kipp, R.M.; Larson, J. & Fusaro, A. (2013). "Potamopyrgus antipodarum". USGS Nonindigenous Aquatic Species Database. U.S. Geological Survey. Retrieved 25 May 2013.
  7. Holomuzki, J. R. and B. J. F. Biggs. 2006. Habitat–specific variation and performance trade–offs in shell armature of New Zealand mudsnails. Ecology 87(4):1038–1047.
  8. Hall, R. O. Jr., J. L. Tank and M. F. Dybdahl. 2003. Exotic snails dominate nitrogen and carbon cycling in a highly productive stream. Frontiers in Ecology and the Environment 1(8):407–411.
  9. Timothy M. Davidson, Valance E. F. Brenneis, Catherine de Rivera, Robyn Draheim & Graham E. Gillespie. Northern range expansion and coastal occurrences of the New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) in the northeast Pacific Archived 2011-07-21 at the Wayback Machine Aquatic Invasions (2008) Volume 3, Issue 3: 349-353.
  10. Murtada D. Naser & Mikhail O. Son. 2009. First record of the New Zealand mud snail Potamopyrgus antipodarum (Gray 1843) from Iraq: the start of expansion to Western Asia? Archived 2011-07-21 at the Wayback Machine. Aquatic Invasions, Volume 4, Issue 2: 369-372, DOI 10.3391/ai.2009.4.2.11.
  11. "Knapweeds, Invasive Species Council Priority Species". invasivespecies.wa.gov. Retrieved 2019-06-30.
  12. Nentwig, Wolfgang; Bacher, Sven; Kumschick, Sabrina; Pyšek, Petr; Vilà, Montserrat (2017-12-18). "More than "100 worst" alien species in Europe". Biological Invasions. 20 (6): 1611–1621. doi:10.1007/s10530-017-1651-6. ISSN 1387-3547.
  13. Mikhail O. Son. Rapid expansion of the New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) in the Azov-Black Sea Region Archived 2011-07-21 at the Wayback Machine. Aquatic Invasions (2008) Volume 3, Issue 3: 335-340.
  14. Paludestrina jenkinsi in Lough Neagh and elsewhere. Irish Naturalists’ Journal 1: 174-175.
  15. Čejka T., Dvořák L. & Košel V. 2008: Present distribution of Potamopyrgus antipodarum (Gray, 1843) (Mollusca: Gastropoda) in the Slovak Republic. - Malacologica Bohemoslovaca, 7: 21-25. Online serial at <http://mollusca.sav.sk&gt Archived 2018-12-25 at the Wayback Machine; 25-February-2008.
  16. Dmitry P. Filippenko & Mikhail O. Son. The New Zealand mud snail Potamopyrgus antipodarum (Gray, 1843) is colonising the artificial lakes of Kaliningrad City, Russia (Baltic Sea Coast) Archived 2011-07-21 at the Wayback Machine. Aquatic Invasions (2008) Volume 3, Issue 3: 345-347.
  17. Boris Alexandrov, Alexandr Boltachev, Taras Kharchenko, Artiom Lyashenko, Mikhail Son, Piotr Tsarenko & Valeriy Zhukinsky. Trends of aquatic alien species invasions in Ukraine Archived 2011-07-21 at the Wayback Machine. Aquatic Invasions (2007) Volume 2, Issue 3: 215-242.
  18. Canella Radea, Ioanna Louvrou and Athena Economou-Amilli First record of the New Zealand mud snail Potamopyrgus antipodarum J.E. Gray 1843 (Mollusca: Hydrobiidae) in Greece – Notes on its population structure and associated microalgae Archived 2011-07-21 at the Wayback Machine. Aquatic Invasions (2008) Volume 3, Issue 3: 341-344
  19. Kuchař P. Potamopyrgus jenkinsi poprvé v Československu. Źiva, Prague, 31(1): page 23. (in Czech).
  20. "Biology". New Zealand mudsnails in the Western USA. Montana State University. Archived from the original on 2006-05-04. Retrieved 2006-05-04.
  21. Benson, Amy (2006). "New Zealand Mudsnail: Potamopyrgus antipodarum". Florida Integrated Science Center. Archived from the original on 2006-02-19. Retrieved 2006-05-04.
  22. Davis, Ken W. (2004-02-24). "Select Research Findings on the New Zealand Mudsnail (Potamopyrgus antipodarum)" (PDF). Wildlife Survey & Photo Service. p. 1. Archived from the original (PDF) on 2006-05-26. Retrieved 2006-05-07.
  23. Aamio, K. and E. Bornsdorff. 1997. Passing the gut of juvenile flounder Platichthys flesus (L.) – differential survival of zoobenthic prey species. Marine Biology 129: 11–14.
  24. "Non-native snail turns up in Truckee River". Elko Daily Free Press. 20 May 2013. p. 4.
  25. "News Release - Discovery of Invasive New Zealand Mud Snail Forces Temporary Closure of Putah Creek". California Department of Fish and Game. 2003-12-16. Archived from the original on 2004-02-02. Retrieved 2006-05-07.
  26. "Western USA Potamopyrgus antipodarum morphs". Department of Ecology, Montana State University-Bozeman. 2006-02-22. Archived from the original on 2006-04-29. Retrieved 2006-05-07.
  27. Levri, Edward P.; Dermott, Ron M.; Lunnen, Shane J.; Kelly, Ashley A.; Ladson, Thomas (2008). "The distribution of the invasive New Zealand mud snail (Potamopyrgus antipodarum) in Lake Ontario" (PDF). Aquatic Ecosystem Health and Management. 11 (4): 412–421. doi:10.1080/14634980802523140. Archived (PDF) from the original on 2016-01-14.
  28. New Zealand Mud Snails Invade Lake Erie!, International Association for Great Lakes Research, 26 March 2007.
  29. "Invasive snail found in Minn. harbor". NBC News. Associated Press. 2006-05-03. Archived from the original on 2019-05-23. Retrieved 2019-05-23.
  30. "Worrying invasive snail found in Lake Michigan". CTV News. The Associated Press. 2008-08-16. Archived from the original on 2008-09-02.
  31. Dodge, John (2010-10-19). "Snail seclusion successful". The Olympian. Archived from the original on 2012-09-13. Retrieved 2011-03-31.
  32. Shannon, Brad (4 December 2013). "Freeze could help kill Capitol Lake's mudsnail population". The News Tribune. Archived from the original on 27 December 2013.
  33. Shannon, Brad (26 December 2013). "Cold estimated to have killed half of snails in Capitol Lake". The Olympian. Archived from the original on 27 December 2013.
  34. "South-Central/Southern California Coast Steelhead Recovery Planning Domain 5-Year Review: Summary and Evaluation of Southern California Coast Steelhead Distinct Population Segment" (PDF). National Oceanic and Atmospheric Administration. 2011. Retrieved 2013-12-03.
  35. Leovy, Jill (March 30, 2010). "Hard-to-kill snails infest Santa Monica Mountain watersheds". Los Angeles Times. Archived from the original on 2019-05-23. Retrieved 20 July 2018.
  36. Collier, K. J., R. J. Wilcock and A. S. Meredith. 1998. Influence of substrate type and physico–chemical conditions on macroinvertebrate faunas and biotic indices in some lowland Waikato, New Zealand, streams. New Zealand Journal of Marine and Freshwater Research 32(1):1–19.
  37. Holomuzki, J. R. and B. J. F. Biggs. 1999. Distributional responses to flow disturbance by a stream–dwelling snail. Oikos 87(1):36–47.
  38. Holomuzki, J. R. and B. J. F. Biggs. 2000. Taxon–specific responses to high–flow disturbances in streams: implications for population persistence. Journal of the North American Benthological Society 19(4):670–679.
  39. Negovetic, S. and J. Jokela. 2000. Food choice behaviour may promote habitat specificity in mixed populations of clonal and sexual Potamopyrgus antipodarum. Experimental Ecology 60(4):435–441.
  40. Richards, D. C., L. D. Cazier and G. T. Lester. 2001. Spatial distribution of three snail species, including the invader Potamopyrgus antipodarum, in a freshwater spring. Western North American Naturalist 61(3):375–380.
  41. Weatherhead, M. A. and M. R. James. 2001. Distribution of macroinvertebrates in relation to physical and biological variables in the littoral zone of nine New Zealand lakes. Hydrobiologia 462(1–3):115–129.
  42. Death, R. G., B. Baillie and P. Fransen. 2003. Effect of Pinus radiata logging on stream invertebrate communities in Hawke’s Bay, New Zealand. New Zealand Journal of Marine and Freshwater Research 37(3):507–520.
  43. Schreiber, E. S. G., G. P. Quinn and P. S. Lake. 2003. Distribution of an alien aquatic snail in relation to flow variability, human activities and water quality. Freshwater Biology 48(6):951–961.
  44. Suren, A. M. 2005. Effects of deposited sediment on patch selection by two grazing stream invertebrates. Hydrobiologia 549(1):205–218.
  45. Jacobsen, R. and V. E. Forbes. 1997. Clonal variation in life–history traits and feeding rates in the gastropod, Potamopyrgus antipodarum: performance across a salinity gradient. Functional Ecology 11(2):260–267.
  46. Leppäkoski, E. and S. Olenin. 2000. Non–native species and rates of spread: lessons from the brackish Baltic Sea. Biological Invasions 2(2):151–163.
  47. Costil, K., G.B. J. Dussart and J. Daquzan. 2001. Biodiversity of aquatic gastropods in the Mont St–Michel basin (France) in relation to salinity and drying of habitats. Biodiversity and Conservation 10(1):1–18.
  48. Gerard, C., A. Blanc and K. Costil. 2003. Potamopyrgus antipodarum (Mollusca: Hydrobiidae) in continental aquatic gastropod communities: impact of salinity and trematode parasitism. Hydrobiologia 493(1–3):167–172.
  49. Cox, T. J. and J. C. Rutherford. 2000. Thermal tolerances of two stream invertebrates exposed to diurnally varying temperature. New Zealand Journal of Marine and Freshwater Research 34(2):203–208.
  50. Broekhuizen, N., S. Parkyn and D. Miller. 2001. Fine sediment effects on feeding and growth in the invertebrate grazer Potamopyrgus antipodarum (Gastropoda, Hydrobiidae) and Deleatidium sp. (Ephemeroptera, Letpophlebiidae). Hydrobiologia 457(1–3):125–132.
  51. James, M. R., I. Hawes and M. Weatherhead. 2000. Removal of settled sediments and periphyton from macrophytes by grazing invertebrates in the littoral zone of a large oligotrophic lake. Freshwater Biology 44(2):311–326.
  52. Kelly, D. J. and I. Hawes. 2005. Effects of invasive macrophytes on littoral–zone productivity and foodweb dynamics in a New Zealand high–country lake. Journal of the North American Benthological Society 24(2):300–320.
  53. Parkyn, S. M., J. M. Quinn, T. J. Cox and N. Broekhuizen. 2005. Pathways of N and C uptake and transfer in stream food webs: an isotope enrichment experiment. Journal of the North American Benthological Society 24(4):955–975.
  54. Fox J., Dybdahl M., Jokela J., Lively C. (1996). Genetic structure of coexisting sexual and clonal subpopulations in a freshwater snail (Potamopyrgus antipodarum). Evolution. 50 (4): 1541-1548
  55. Schreiber, E. S. G., A. Glaister, G. P. Quinn and P. S. Lake. 1998. Life history and population dynamics of the exotic snail Potamopyrgus antipodarum (Prosobranchia: Hydrobiidae) in Lake Purrumbete, Victoria, Australia. Marine and Freshwater Research 49(1):73–78.
  56. Lively, C. M. and J. Jokela. 2002. Temporal and spatial distribution of parasites and sex in a freshwater snail. Evolutionary Ecology Research 4(2):219–226.
  57. "New Zealand mudsnail (Potamopyrgus antipodarum)". Kansas Department of Wildlife and Parks. 2006. Retrieved 2006-05-04.
  58. Larval Trematoda: Winterbourne
  59. Dybdahl, M. F. and A. C. Krist. 2004. Genotypic vs. condition effects on parasite–driven rare advantage. Journal of Evolutionary Biology 17(5):967–973.
  60. About Microphallus
  61. Levri, E. P. 1998. Perceived predation risk, parasitism, and the foraging behavior of a freshwater snail (Potamopyrgus antipodarum). Canadian Journal of Zoology 76(10):1878–1884.

Further reading
  • Kerans, B. L, M. F. Dybdahl, M. M. Gangloff and J. E. Jannot. 2005. Potamopyrgus antipodarum: distribution, density, and effects on native macroinvertebrate assemblages in the Greater Yellowstone ecosystem. Journal of the North American Benthological Society 24(1):123–138.
  • Strzelec, M. 2005. Impact of the introduced Potamopyrgus antipodarum (Gastropods) on the snail fauna in post–industrial ponds in Poland. Biologia (Bratislava) 60(2):159–163.
  • de Kluijver, M. J.; Ingalsuo, S. S.; de Bruyne, R. H. (2000). Macrobenthos of the North Sea [CD-ROM]: 1. Keys to Mollusca and Brachiopoda. World Biodiversity Database CD-ROM Series. Expert Center for Taxonomic Identification (ETI): Amsterdam, The Netherlands. ISBN 3-540-14706-3. 1 cd-rom.
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