''Radix auricularia'', the big-ear radix, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of medium-sized freshwater snail, an aquatic pulmonate gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Lymnaeidae Lymnaeidae, common name the pond snails, is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila. Lymnaeidae is the only family within the superf ...

.Neubauer, Thomas A.; Rosenberg, G.; Gofas, S. (2014). Radix auricularia (Linnaeus, 1758). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=248263 on 2014-11-17 ''Radix auricularia'' is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

of the genus '' Radix''.

Forms

Forms of ''Radix auricularia'' include: *''Radix auricularia'' f. ''tumida'' (Held, 1836) *''Radix auricularia'' f. ''subampla'' (Ehrmann, 1933)

Shell description

The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

is thin, roundly ovate and very inflated, such that the

last whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk ...

comprises 90% of its volume.Clarke, A.H. 1981. ''The freshwater molluscs of Canada''. National Museum of Natural Sciences, National Museums of Canada, Ottawa, Canada. 447 pp. The shell has a rounded and broad

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires a ...

that pinches in steeply at the

apex The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics), a teenaged super villainess in the Marvel Universe * Ape-X, a super-intelligent ape in the Squadron Supreme universe *Apex, ...

. The spire short, conic, very small compared with the body whorl. There are 4–5

whorls A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

with deep sutures between them. The whorls are convex, inflated, smooth and rapidly increasing. The body whorl is large and spreading. The surface is shining, lines of growth are fine, wavy, crowded, with occasionally a heavy ridge representing a rest period. Sutures are deeply impressed, channeled in some specimens. The color of the shell is yellow, beige or tan. The ear-shaped

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An ...

, which contains no operculum, is around 5 times higher than the spire.Jokinen, E. 1992. ''The Freshwater Snails (Mollusca: Gastropoda) of New York State''. The University of the State of New York, The State Education Department, The New York State Museum, Albany, New York 12230. 112 pp.Peckarsky, B. L., P. R. Fraissinet, M. A. Penton and D. J. Conklin Jr. 1993. ''Freshwater Macroinvertebrates of Northeastern North America''. Cornell University Press, Ithaca, New York State. 442 pp.Mackie, G. L., D. S. White and T. W. Zdeba. 1980. ''A guide to freshwater mollusks of the Laurentian Great Lakes with special emphasis on the genus Pisidium''. Environmental Research Laboratory, Office of Research and Development, U. S. Environmental Protection Agency, Duluth, Minnesota 55804. 144 pp. The aperture is very large, ovate, occupying four-fifths of the length of the entire shell. It is rounded above and flaring in old specimens below. The peristome is thin and sharp. The

columella Lucius Junius Moderatus Columella (; Arabic: , 4 – ) was a prominent writer on agriculture in the Roman Empire. His ' in twelve volumes has been completely preserved and forms an important source on Roman agriculture, together with the wo ...

is sigmoid with a plait across the middle, which is reflected over the umbilicus. The umbilicus is either wide or covered. Usually the umbilicus is narrow, deep, nearly closed. The epidermis is sometimes marked by light and dark lines of color, alternating. The shell of the species can grow to ~30 mm in height and 25 mm in width as a full grown adult. However, most individuals in a population only grow to approximately half the maximum size. The width of the shell is from 12–18 mm, and the height of the shell is 14–24 mm.Glöer, P. 2002 ''Die Süßwassergastropoden Nord- und Mitteleuropas''. Die Tierwelt Deutschlands, ConchBooks, Hackenheim, 326 pp., , page 213-214. The shell of ''Radix auricularia'' has a width to length ratio greater than 0.75.

Anatomy

Natural History - Mollusca - Limneus Auricularis

The body is flecked with small white spots on the back of the head and tentacles, but not on the foot. The mantle is pigmented with a line of dark spots along its edge, irregular spots which show through the shell. The foot is roundly elongated, 18 × 11 mm. The head is broad, auriculated. This species also has

tentacles In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainl ...

that are large, flat, lobate, triangular, fan-shaped and wider than they are high.Jackiewicz, M. and R. Buksalewicz. 1998. ''Diversity in tentacle shape of European lymnaeid species (Gastropoda, pulmonata: Basommatophora)''. Biological Bulletin of Poznan 35(2):131–136. The blood contains blue

hemocyanin Hemocyanins (also spelled haemocyanins and abbreviated Hc) are proteins that transport oxygen throughout the bodies of some invertebrate animals. These metalloproteins contain two copper atoms that reversibly bind a single oxygen molecule (O2) ...

.Jing, Z. 1983. ''Anatomy of the circulatory system of Radix auricularia''. Acta Zoologica Sinica 29(2):133–140. The heart pulsations are slow and regular: thirty-four per minute. The animal is slow and deliberate in its movements.

Distribution

Indigenous distribution

''Radix auricularia'' is native to Europe and most of the Palearctic including Oman, Tibet and Vietnam In Europe it occurs in: * Croatia * Finland *

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

* Sweden * British Isles:

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It i ...

and

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. nnotated list of mollusc species recorded outdoors in the Czech and Slovak Republics. ''

Malacologica Bohemoslovaca ''Malacologica Bohemoslovaca'' is a peer-reviewed open access scientific journal covering all aspects of malacology. It was published by the Slovak Academy of Sciences since 2005. It is published by the Department of Botany and Zoology, Faculty of ...

'', Suppl. 1: 1–37
PDF
*

Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the s ...

* and others In Asia it occurs across the East Palearctic and in *

Oman Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of ...

Soliman M. F. M. (2008). "Epidemiological review of human and animal fascioliasis in Egypt". '' The Journal of Infection in Developing Countries'' 2(3): 182–189
abstractPDF
/ref> *

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

– in northern VietnamDung B. T., Doanh P. N., The D. T., Loan H. T., Losson B. & Caron Y. (2013). "Morphological and Molecular Characterization of Lymnaeid Snails and Their Potential Role in Transmission of ''Fasciola'' spp. in Vietnam". '' Korean Journal of Parasitology'' 51(6): 657–662. . * and others

Nonindigenous distribution

''Radix auricularia'' is an introduced species in the United States and New Zealand. In the Mid-Atlantic Region it is found in the

Charles River The Charles River ( Massachusett: ''Quinobequin)'' (sometimes called the River Charles or simply the Charles) is an river in eastern Massachusetts. It flows northeast from Hopkinton to Boston along a highly meandering route, that doubles b ...

in Massachusetts,

Cayuga Lake Cayuga Lake (,,) is the longest of central New York's glacial Finger Lakes, and is the second largest in surface area (marginally smaller than Seneca Lake) and second largest in volume. It is just under long. Its average width is , and it is ...

and the

Hudson River The Hudson River is a river that flows from north to south primarily through eastern New York. It originates in the Adirondack Mountains of Upstate New York and flows southward through the Hudson Valley to the New York Harbor between N ...

New York State New York, officially the State of New York, is a state in the Northeastern United States. It is often called New York State to distinguish it from its largest city, New York City. With a total area of , New York is the 27th-largest U.S. stat ...

, in various ponds in

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...

, New York, and

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

, and in

Lake Champlain Lake Champlain ( ; french: Lac Champlain) is a natural freshwater lake in North America. It mostly lies between the US states of New York and Vermont, but also extends north into the Canada, Canadian province of Quebec. The New York portion of t ...

in Vermont. In the Great Lakes Region: The first record of ''Radix auricularia'' in North America is from the Hudson River (which is connected through the New York Canal System to Lakes Erie and Ontario) near

Troy, New York Troy is a city in the U.S. state of New York and the county seat of Rensselaer County. The city is located on the western edge of Rensselaer County and on the eastern bank of the Hudson River. Troy has close ties to the nearby cities of Albany ...

, before 1869.Mills, E. L., J. H. Leach, J. T. Carlton and C. L. Secor. 1993. ''Exotic species in the Great Lakes: a history of biotic crises and anthropogenic introductions''. Journal of Great Lakes Research 19(1):1–54. The next record is from

Lincoln Park, Chicago Lincoln Park is a designated community area on the North Side of Chicago, Illinois. Lying to the west of Lincoln Park, Chicago's largest park, it is one of the most affluent neighborhoods in Chicago. History In 1824, the United States ...

, beside Lake Michigan in 1901. Subsequently, it was found in

Lake Erie Lake Erie ( "eerie") is the fourth largest lake by surface area of the five Great Lakes in North America and the eleventh-largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also h ...

and a tributary stream in 1911 and in 1948, and in

Lake Ontario Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York. The Canada–United States border ...

in 1930. It is also reported from Lake Huron.Dundee, D. S. 1974. ''Catalogue of introduced mollusks of eastern North America (north of Mexico)''. Sterkiana 55:1–37. This species has shown a potential to adapt to new environments within large lakes, as indicated by its recent history in Lake Baikal, Russia, where this introduced species was previously restricted to shallow bays and floodplain areas, but has recently been able to colonize the rocky drop-off in the lake.Stift, M., E. Michel, T. Y. Sitnikova, E. Y. Mamonova and D. Y. Sherbakov. 2004. ''Palaearctic gastropod gains a foothold in the dominion of endemics: range expansion and morphological change of Lymnaea (Radix) auricularia in Lake Baikal''. Hydrobiologia 513(1–3):101–108. The shells of those snails in the new habitat have a more inflated aperture and are more compact than those in the shallow zones, indicating that wave action may have selected for snails with a stronger suctioning foot in the newly colonized habitat.

Ecology

Habitat

This species is found in freshwater lakes, ponds, and slow-moving rivers with mud bottoms. ''Radix auricularia'' can live on boulders or vegetation in low or high-flow environments, and is capable of tolerating

anoxic The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...

conditions, but it tends to prefer very lentic waters in lakes, bogs or slow rivers where there is a silt substrate.Sytsma, M. D., J. R. Cordell, J. W. Chapman and R. C. Draheim. 2004. ''Lower Columbia River Aquatic Nonindigenous Species Survey 2001–2004''. Final Technical Report: Appendices. Prepared for the United States Coast Guard and the United States Fish and Wildlife Service. 164 pp. It has been found in environments with a pH from 6.0–7.1.Maqbool, A., C. S. Hayat, T. Akhtar, A. D. Anjum and B. Hayat. 1998. ''Prevalence and ecology of freshwater snails in Punjab''. Malaysian Applied Biology 27(1–2):69–72. Its average thermal preference is ~19 °C, but there is great fluctuation around this mean, depending on the photoperiod for the time of year.Rossetti, Y., L. Rossetti and M. Cabanac. 1989. ''Annual oscillation of preferred temperature in the freshwater snail Lymnaea auricularia; effect of light and temperature''. Animal Behaviour 37(6):897–907. In Great Britain, the species is restricted to hard water.Adam, M. E. and J. W. Lewis. 1992. ''The lack of co-existence between Lymnaea peregra and Lymnaea auricularia (Gastropoda: Pulmonata)''.

Journal of Molluscan Studies The ''Journal of Molluscan Studies'' is the peer-reviewed scientific journal of the Malacological Society of London, covering research in malacology.

58(2):227–228. It can tolerate polysaprobic waters, or areas of major pollution and anoxia with high concentrations of organic matter, sulfides and

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

.Goodnight, C. J. 1973. ''The use of aquatic macroinvertebrates as indicators of stream pollution''. Transactions of the American Microscopical Society 92(1):1–13.Matuskova, M. 1985. ''The significance of water mollusks in estimating the water pollution stage in the watershed of the Zitava River, Czechoslovakia''. Biologia (Bratislava) 40(10):1021–1030.

Feeding habits

''Radix auricularia'' is in the family Lymnaeidae, which consists of scrapers and collector-gatherers. This species feeds on such items as detritus, ''

Cladophora ''Cladophora'' is a genus of reticulated filamentous Ulvophyceae (green algae). The genus ''Cladophora'' contains many species that are very hard to tell apart and classify, mainly because of the great variation in their appearances, which is a ...

'' spp. (algae), and sand grains.

Life cycle

Like almost all pulmonate snails, it is a hermaphrodite. It undergoes oogenesis in spring as the daylight hours increase, and spermatogenesis in late summer and early fall as the daylight hours decrease.Berezkina, G. V. 1981. ''Seasonal changes in reproductive system of the Lymnaeidae''. Zoologicheskii Zhurnal 60(7):978–983. It is

iteroparous Semelparity and iteroparity are two contrasting reproductive strategies available to living organisms. A species is considered semelparous if it is characterized by a single reproductive episode before death, and iteroparous if it is characteri ...

, breeding biennially. It lays its eggs in clumps of 50 to 150 eggs. Eggs develop faster as temperature increases from 10 °C upward, but the eggs fail to survive and develop when the water temperature reaches 36 °C.Salish, T., O. Al-Habbib, W. Al-Habbib, S. Al-Zako and T. Ali. 1981. ''The effects of constant and changing temperatures of the development of eggs of the freshwater snail Lymnaea auricularia (L.)''.

Journal of Thermal Biology The ''Journal of Thermal Biology'' is a peer-reviewed academic journal An academic journal or scholarly journal is a periodical publication in which scholarship relating to a particular academic discipline is published. Academic journals ser ...

Parasites

Various lymnaeid snails, including ''Radix auricularia'', are vectors for a diverse range of parasites, particularly

trematode Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive h ...

s.Boray, J. C. 1978. ''The potential impact of exotic Lymnaea spp. on fascioliasis in Australia''. Veterinary Parasitology 4(2):127–142. About 80% specimens of ''Radix auricularia'' from population near

Wielkopolska National Park Wielkopolski National Park ( pl, Wielkopolski Park Narodowy, or the National Park of Greater Poland) is a National Park within the Wielkopolska (Greater Poland) region of west-central Poland, approximately south of the regional capital, Poznań. ...

were found to contain trematodes. ''Radix auricularia'' serves as a host to numerous parasites including: * As first and as second intermediate host for: ** '' Echinostoma revolutum'' ** '' Echinoparyphium recurvatum'' ** '' Hypoderaeum conoideum'' *As first intermediate host for: ** '' Clinostomum complanatum'' * As a second intermediate host for: ** '' Apatemon gracilis'' *As an intermediate host for: ** ''Radix auricularia'' is the most important intermediate host for ''

Fasciola gigantica ''Fasciola gigantica'' is a parasitic flatworm of the class Trematoda, which causes tropical fascioliasis. It is regarded as one of the most important single platyhelminth infections of ruminants in Asia and Africa. Estimates of infection rates ...

''. ** as an intermediate host for ''

Fasciola hepatica ''Fasciola hepatica'', also known as the common liver fluke or sheep liver fluke, is a parasitic trematode (fluke or flatworm, a type of helminth) of the class Trematoda, phylum Platyhelminthes. It infects the livers of various mammals, includi ...

'' in Oman. ** '' Notocotylus attenuatus'' * As a

paratenic host In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' ( symbiont). The guest is typically provided with nourishment and shelter. Examples include ...

for: ** '' Hymenolepis lanceolata'' As a host for: * '' Trichobilharzia franki'' * '' Trichobilharzia ocellata'' * '' Trichobilharzia szidati'' * '' Mantoscyphidia '' * '' Orientobilharzia turkestanica'' * '' Diplostomum spathaceum''Soldanova M., Selbach C., Sures B., Kostadinova A. & Perez-del-Olmo A. (2010). "Larval trematode communities in ''Radix auricularia'' and ''Lymnaea stagnalis'' in a reservoir system of the Ruhr River". ''

Parasites & Vectors ''Parasites & Vectors'' is a peer-reviewed open-access medical journal published by BioMed Central. The journal publishes articles on the biology of parasites, parasitic diseases, intermediate hosts, vectors and vector-borne pathogens. ''Paras ...

'' 2010, 3: 56. . * '' Paryphostomum radiatum'' * '' Opisthioglyphe ranae'' * ''

Plagiorchis elegans ''Plagiorchis elegans'' is a species of parasitic trematodes (flukes) in the genus ''Plagiorchis ''Plagiorchis'' is a genus of parasitic trematodes (flukes) in the family Plagiorchiidae Plagiorchiidae is a family of parasitic trematodes (fl ...

'' * '' Australapatemon burti'' * '' Hypoderaeum conoideum'' * '' Isthmiophora melis'' * '' Notocotylus attenuatus'' * '' Tylodelphis clavata'' Some of these parasites may infect humans. One study found that average shell height and infection severity with '' Trichobilharzia'' spp. are positively related. In its native habitat, this species preys on eggs of the parasite ''

Ascaris suum ''Ascaris suum'', also known as the large roundworm of pig, is a parasitic nematode that causes ascariasis in pigs. While roundworms in pigs and humans are today considered as two species (''A. suum'' and '' A. lumbricoides'') with different hos ...

'', which survive and develop after passage through the gut, and are dispersed widely, due to the activity of the snail.Asitinskaya, S. E. 1975. ''The role of mollusks as benthos components in purification of water bodies from Ascaris suum eggs''. Paraziologiya 9(5):432–433.

References

This article incorporates public domain text from references. Baker F. C. (25 April) 1902.
The Mollusca of the Chicago Area
Part II. Gastropoda''. Bulletin No. III. of the Natural History Survey, The Chicago Academy of Sciences, 418 pp. 33 plates. Pag
408
409.Rebekah M. Kipp & Amy Benson. 2008. Radix auricularia.

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

Nonindigenous Aquatic Species Database, Gainesville, FL. Revision Date: 2/28/2007

External links

''Radix auricularia''
at

Animalbase AnimalBase is a project brought to life in 2004 and is maintained by the University of Göttingen, Germany. The goal of the AnimalBase project is to digitize early zoological literature, provide copyright-free open access to zoological works, and pr ...

MolluscIreland
{{DEFAULTSORT:Radix Auricularia Lymnaeidae Gastropods described in 1758 Taxa named by Carl Linnaeus