Valvata piscinalis
Encyclopedia
Valvata piscinalis, common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...

 the European stream valvata, is a species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of minute freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

 with gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

s and an operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 gastropod mollusk in the family Valvatidae
Valvatidae
Valvatidae, the valve snails, is a taxonomic family of very small freshwater snails with an operculum, aquatic gastropod mollusks.- Taxonomy :...

, the valve snails. It is also known as Cincinna piscinalis (Müller, 1774).

Subspecies

Subspecies of Valvata piscinalis include:
  • Valvata piscinalis piscinalis (O. F. Müller, 1774)
  • Valvata piscinalis antiqua (Morris, 1838)
  • Valvata piscinalis geyeri (Menzel, 1904) - The name geyeri is in honor of German zoologist David Geyer
    David Geyer
    David Geyer was German zoologist, malacologist and paleontologist.- Bibliography :Works by David Geyer were published in German language:...

     (1855–1932).
  • Valvata piscinalis discors (Westerlund, 1886)
  • Valvata piscinalis alpestris (Küster, 1853)

Shell description

Valvata piscinalis has a somewhat pinched aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....

 and an attenuate spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...

. The spire height tends to increases in more eutrophic conditions. Shells of this species often exhibit 4–5 whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

 and are white to beige with more orange to red pigmentation apically. The operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

 shows spiral markings of around 10 turns, originating almost centrally.

The European valve snail can be confused with Valvata sincera
Valvata sincera
Valvata sincera, common name the mossy valvata or boreal turret snail, is a species of small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Valvatidae, the valve snails.-Distribution:...

, a native species in the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

; however, the native species has a more spherical aperture, a wider umbilicus, a conical spire and more widely spaced and rough growth lines on the shell in comparison with the introduced species. In the Great Lakes, mature adult European valve snails are 5 mm high and 3–5 mm wide. In Europe, this snail has been found up to 7 mm high and 6.5 mm wide, but is usually smaller.

Dimensions of the shell are:
  • Valvata piscinalis piscinalis - The width of the shell is 4–5 mm. The height of the shell is 3-4.5 mm.
  • Valvata piscinalis antiqua - width: 4.5 mm. height: 6 mm.
  • Valvata piscinalis geyeri - width: 2.5 mm. height: 3 mm.
  • Valvata piscinalis discors - width: 3 mm. height: 3 mm.
  • Valvata piscinalis alpestris - width: 6.3 mm. height: 5.5 mm.

Anatomy

The animals are yellow colored, spotted grey and white, with darker pigmentation on the snout
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...

, mantle and base of the penis. Blue eyes are at the base of long tentacles. Valvatids all exhibit an external bipectinate ctenidium
Ctenidium
Ctenidium may be:* Ctenidium , , a comb-like gill, part of the respiratory system of gastropods and bivalves* Ctenidium, , a row of peg-like spines in some insects...

 (respiratory organ) which is visible as the animal moves around.

Distribution

Distribution of Valvata piscinalis is palearctic
Palearctic
The Palearctic or Palaearctic is one of the eight ecozones dividing the Earth's surface.Physically, the Palearctic is the largest ecozone...

.

Although this species is widely distributed in some areas in North America as an introduced species, Valvata piscinalis has declined in some parts of its native distribution, and in some areas it is endangered.

Indigenous distribution

This species occurs in the British Isles and throughout Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, to Asia Minor
Asia Minor
Asia Minor is a geographical location at the westernmost protrusion of Asia, also called Anatolia, and corresponds to the western two thirds of the Asian part of Turkey...

 and all the way to Tibet
Tibet
Tibet is a plateau region in Asia, north-east of the Himalayas. It is the traditional homeland of the Tibetan people as well as some other ethnic groups such as Monpas, Qiang, and Lhobas, and is now also inhabited by considerable numbers of Han and Hui people...

.

The European valve snail is native to Europe, the Caucasus
Caucasus
The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...

, western Siberia and Central Asia and is common in many freshwater environments therein. It is entirely absent from Iceland.

Europe:
  • Austria - endangered (3, gefährdet)
  • Croatia
  • Czech Republic - near threatened (NT)
  • Slovakia
  • Poland
  • Germany - (Arten der Vorwarnliste): critically endangered (2, stark gefährdet) in Saxony
    Saxony
    The Free State of Saxony is a landlocked state of Germany, contingent with Brandenburg, Saxony Anhalt, Thuringia, Bavaria, the Czech Republic and Poland. It is the tenth-largest German state in area, with of Germany's sixteen states....

     and in Thuringia
    Thuringia
    The Free State of Thuringia is a state of Germany, located in the central part of the country.It has an area of and 2.29 million inhabitants, making it the sixth smallest by area and the fifth smallest by population of Germany's sixteen states....

    , endangered (3, gefährdet) in Berlin
    Berlin
    Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

    , (4R, rückläufig) in Bavaria
    Bavaria
    Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...

    , species with limited distribution in Brandenburg
    Brandenburg
    Brandenburg is one of the sixteen federal-states of Germany. It lies in the east of the country and is one of the new federal states that were re-created in 1990 upon the reunification of the former West Germany and East Germany. The capital is Potsdam...

    , (Arten der Vorwarnliste) in Hesse
    Hesse
    Hesse or Hessia is both a cultural region of Germany and the name of an individual German state.* The cultural region of Hesse includes both the State of Hesse and the area known as Rhenish Hesse in the neighbouring Rhineland-Palatinate state...

     and in North Rhine-Westphalia
    North Rhine-Westphalia
    North Rhine-Westphalia is the most populous state of Germany, with four of the country's ten largest cities. The state was formed in 1946 as a merger of the northern Rhineland and Westphalia, both formerly part of Prussia. Its capital is Düsseldorf. The state is currently run by a coalition of the...

    . In other federal states of Germany the species is common.
  • Netherlands
  • the British Isles: Great Britain and Ireland
  • Sweden - not in red list


Asia:

Nonindigenous distribution

Valvata piscinalis is nonindigenous in the United States.

The European valve snail was originally introduced to Lake Ontario
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north and southwest by the Canadian province of Ontario, and on the south by the American state of New York. Ontario, Canada's most populous province, was named for the lake. In the Wyandot language, ontarío means...

 at the mouth of the Genesee River
Genesee River
The Genesee River is a North American river flowing northward through the Twin Tiers of Pennsylvania and New York. The river provided the original power for the Rochester area's 19th century mills and still provides hydroelectric power for downtown Rochester....

 in 1897. In forty years it dispersed to Lake Erie
Lake Erie
Lake Erie is the fourth largest lake of the five Great Lakes in North America, and the tenth largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. It is bounded on the north by the...

 and subsequently it expanded its range to the Saint Lawrence River
Saint Lawrence River
The Saint Lawrence is a large river flowing approximately from southwest to northeast in the middle latitudes of North America, connecting the Great Lakes with the Atlantic Ocean. It is the primary drainage conveyor of the Great Lakes Basin...

, the Hudson River
Hudson River
The Hudson is a river that flows from north to south through eastern New York. The highest official source is at Lake Tear of the Clouds, on the slopes of Mount Marcy in the Adirondack Mountains. The river itself officially begins in Henderson Lake in Newcomb, New York...

, Champlain Lake and Cayuga Lake
Cayuga Lake
Cayuga Lake   is the longest of central New York's glacial Finger Lakes, and is the second largest in surface area and second largest in volume. It is just under 40 miles long. Its average width is 1.7 miles , and it is at its widest point near Aurora...

. Valvata piscinalis was recorded in the 1990s and the first decade of the 21st century in Superior Bay in Lake Superior
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...

 (Minnesota), Lake Michigan
Lake Michigan
Lake Michigan is one of the five Great Lakes of North America and the only one located entirely within the United States. It is the second largest of the Great Lakes by volume and the third largest by surface area, after Lake Superior and Lake Huron...

 (Wisconsin) and Oneida Lake
Oneida Lake
Oneida Lake is the largest lake entirely within New York State . The lake is located northeast of Syracuse and near the Great Lakes. It serves as one of the links in the Erie Canal. It empties into the Oneida River which flows into the Oswego River which in turn flows into Lake Ontario...

 in the Lake Ontario watershed (New York State).

Habitat

This small snail is found in freshwater streams, rivers, and lakes, preferring running water and tolerating water with low calcium levels.

In its native range, this species’ presence has been associated with oligotrophic nearshore zones, clear-water habitats more than turbid water, sparsely vegetated lakes or sites dominated by Chara spp. and Potamogeton
Potamogeton
Potamogeton is a genus of aquatic, mostly freshwater, plants of the family Potamogetonaceae. Most are known by the common name pondweed, although many unrelated plants may be called pondweed, such as Canadian pondweed...

spp., littoral habitats with high siltation rates, lentic and stagnant waters or slow streams, fine substrates (mud, silt and sand) – especially during hibernation, and aquatic macrophytes – for laying its egg masses.

The snail appears to be somewhat resistant to declines in macrophyte cover, because populations have been recorded to survive in ponds after vegetation cover almost completely disappeared. This species is found at depths anywhere from 0.5 m to 23 m in the Great Lakes. In Europe, it usually is found in depths of up to 10 m.

Valvata piscinalis tolerates varying calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 concentrations, and generally does not require very high temperatures to survive. Individuals can overwinter in mud, often experiencing growth during this cold period, although some populations may experience mortality in frozen littoral zones. This species can tolerate salinities up to 0.2% and is distributed in northern parts of the Curonian Lagoon
Curonian Lagoon
The Curonian Lagoon is separated from the Baltic Sea by the Curonian Spit. Its surface area is . The Neman River supplies about 90% of its inflows; its watershed consists of about 100,450 square kilometers in Lithuania and the Kaliningrad Oblast.-Human history:In the 13th century, the area around...

, where it experiences periodic intrusions of saline water for a few hours or days at a time.

Feeding habits

The species is an efficient feeder, grazing on epiphytic algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 and detritus
Detritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...

, and in more eutrophic environments is capable of filter feeding
Filter feeder
Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...

 on suspended organic matter and algae. Valvata piscinalis can also rasp off pieces of aquatic vegetation.

Life cycle

Valvata piscinalis is known for its rapid growth and high fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...

. It reproduces as a hermaphrodite
Hermaphrodite
In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...

, one individual acting as the male and the other as the female, and has no free larval stage. It may spawn 2 or 3 times in a year, laying up to 150 eggs at a time which are deposited on vegetation. Hatching normally occurs in 15–30 days. Individuals breed around the age of 1 and usually die at 13–21 months. In Europe, breeding occurs from April to September, occurring later at more northerly latitudes.

Parasites

Valvata piscinalis is a common first intermediate host
Intermediate host
A secondary host or intermediate host is a host that harbors the parasite only for a short transition period, during which some developmental stage is completed. For trypanosomes, the cause of sleeping sickness, humans are the primary host, while the tsetse fly is the secondary host...

 for the parasitic trematode Echinoparyphium recurvatum and has also been shown to act as the first and second intermediate hosts to Echinoparyphium mordwilokoi in native environments in Europe.
  • As second intermediate host for Cyanthocotyle bushiensis
  • As intermediate host for Syngamus trachea

Other interspecific relationships

The snail also has chemosensory perception, which allows it to detect nearby leech
Leech
Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways...

es, and distinguish molluscivores from non-molluscivores, and thus it can close its operculum to avoid predation.

Further reading

  • 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.
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