Bithynia tentaculata
Encyclopedia
Bithynia tentaculata, common names the mud bithynia or common bithynia, or faucet snail is a relatively small 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 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...

 prosobranch gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Bithyniidae
Bithyniidae
Bithyniidae is a family of small freshwater snails with an operculum, aquatic gastropod molluscs in the clade Littorinimorpha.Their minute shell is often colored. They are characterized by a calcareous operculum, a lobe on the upper surface of the neck. The ctenidium, the respiratory gill-comb, is...

.

Forms

  • Bithynia tentaculata f. codia
  • Bithynia tentaculata f. excavata
  • Bithynia tentaculata f. gigas
  • Bithynia tentaculata f. producta Menke, 1828

Shell description

The height of shell
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...

 is usually no larger than 12–15 mm. The snail is sexually mature by the time the height of shell reaches 8 mm in size.

The width of the shell is 5–7 mm.

The faucet snail has a shiny pale brown shell, oval in shape, with a relatively large and rounded 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...

 consisting of 5–6 somewhat flattened 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...

, no umbilicus, and a very thick lip. The 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....

 is less than half the height of the shell.

Adult Bithynia tentaculata possess a white, calcareous, tear-drop to oval-shaped 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...

 with distinct concentric rings. The operculum of juveniles, however, is spirally marked. The operculum is always located very close to the aperture of the shell. The animal itself has pointed, long tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...

s and a simple foot with the right cervical lobe acting as a channel for water.

Indigenous distribution

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

.
  • Croatia
  • Czech Republic - least concern (LC)
  • Germany - common species in the whole Germany, but it is in listed as endangered (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....

  • Greece
  • Poland
  • Netherlands
  • Scandinavia
  • Slovakia
  • Ukraine
  • British Isles: Great Britain and Ireland
  • ...

Nonindigenous distribution

Bithynia tentaculata is nonindigenous in the United States and in Canada.

Great Lakes Region: Bithynia tentaculata was first recorded in 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...

 in 1871, but was probably introduced in 1870. It spread 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...

 by 1879, 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...

 by 1892, and other tributaries and water bodies in the Finger Lakes
Finger Lakes
The Finger Lakes are a pattern of lakes in the west-central section of Upstate New York in the United States. They are a popular tourist destination. The lakes are long and thin , each oriented roughly on a north-south axis. The two longest, Cayuga Lake and Seneca Lake, are among the deepest in...

 region during the 20th century. It was introduced 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...

 sometime before 1930. This snail’s range extends in 1992 from Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

 and Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...

 to Pennsylvania
Pennsylvania
The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...

 and New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

. It has been recorded from Lake Huron
Lake Huron
Lake Huron is one of the five Great Lakes of North America. Hydrologically, it comprises the larger portion of Lake Michigan-Huron. It is bounded on the east by the Canadian province of Ontario and on the west by the state of Michigan in the United States...

, but only a few individuals were found in benthic samples from Saginaw Bay
Saginaw Bay
Saginaw Bay is a bay within Lake Huron located on the eastern side of the U.S. state of Michigan. It forms the space between Michigan's Thumb region and the rest of the Lower Peninsula of Michigan. Saginaw Bay is in area...

 in the 1980s and 1990s.

In the Mid-Atlantic Region it is found in Lake Champlain
Lake Champlain
Lake Champlain is a natural, freshwater lake in North America, located mainly within the borders of the United States but partially situated across the Canada—United States border in the Canadian province of Quebec.The New York portion of the Champlain Valley includes the eastern portions of...

, widespread across New York, Potomac River
Potomac River
The Potomac River flows into the Chesapeake Bay, located along the mid-Atlantic coast of the United States. The river is approximately long, with a drainage area of about 14,700 square miles...

 in Virginia. Established in Chesapeake Bay
Chesapeake Bay
The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West...

, Maryland (Ruiz 2000).

Habitat

This snail is found in freshwater slowly running waters: rivers and standing water bodies: lakes. The species flourishes especially in calcium-rich waters.

Commonly found in freshwater ponds, shallow lakes, and canals. This species is found on the substrate in fall and winter (including gravel, sand, clay, mud or undersides of rocks) and on aquatic macrophytes (including milfoil
Milfoil
Milfoil can refer to:*The flowering terrestrial plant yarrow *The aquatic plants in Genus Myriophyllum...

, Myriophyllum spicatum
Myriophyllum spicatum
Myriophyllum spicatum is a species of Myriophyllum native to Europe, Asia, and north Africa. It is a submerged aquatic plant, and grows in still or slow-moving water.-Description:...

and muskgrass, Chara spp.) in warmer months.
It lives mostly in shoals, but is found at depths up to 5 m. Bithynia tentaculata can inhabit intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...

s in 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...

 In general, the faucet snail inhabits waters with pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

 of 6.6–8.4, conductivity of 87–2320 μmhos/cm, Ca2+ of 5–89 ppm
PPM
- Culture :*Peter, Paul and Mary, a 1960s folk music trio*Picture Postcard Monthly, a magazine for collectors of postcards*Please Please Me, the first album by The Beatles- Health :*Permanent pacemaker or artificial pacemaker...

, and Na+ of 4–291 ppm. It can potentially survive well in water bodies with high concentrations of K+ and low concentrations of NO3-
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...

. In 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...

, it tends to occur in relatively unpolluted, nearshore areas and amongst dreissenid
Dreissena
Dreissena is a genus of small freshwater mussels in the family Dreissenidae.-Species:* Dreissena polymorpha, the zebra mussel** Dreissena polymorpha polymorpha** Dreissena polymorpha andrusovi* Dreissena bugensis, the quagga mussel...

 mussel beds.

Feeding habits

This species functions as both a scraper and a collector-filterer, grazing on algae on the substrate, as well as using its gills to filter suspended algae from the water column. When filter feeding, algae is sucked in, condensed, and then passed out between the right tentacle and exhalant siphon in pellet-like packages which are then eaten. The ability to filter feed may play a role in allowing populations of the faucet snail to survive at high densities in relatively eutrophic, anthropogenically influenced water bodies. Bithynia tentaculata feeds selectively on food items. The faucet snail is known in Eurasia to feed on black fly
Black fly
A black fly is any member of the family Simuliidae of the Culicomorpha infraorder. They are related to the Ceratopogonidae, Chironomidae, and Thaumaleidae. There are over 1,800 known species of black flies . Most species belong to the immense genus Simulium...

 larvae.

Life cycle

Bithynia tentaculata is dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...

 (it has two separate sexes) and lays its eggs on rocks, wood and shells in organized aggregates arranged in double rows, in clumps of 1–77. Egg-laying occurs from May to July when water temperature is 20°C or higher, and sometimes a second time in October and November by females born early in the year. The density of eggs on the substrate can sometimes reach 155 clumps/m2. 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...

 may reach up to 347 eggs and is greatest for the 2nd year class. Eggs hatch in three weeks to three months, depending on water temperature. Oocyte
Oocyte
An oocyte, ovocyte, or rarely ocyte, is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell which undergoes a mitotic...

s develop poorly at temperatures of 30 - 34°C. Growth usually does not occur from September to May. The lifespan varies regionally and can be anywhere from 17 – 39 months.

The faucet snail has the potential to be a good biomonitor for contaminants such as Cd
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...

, Zn
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

, and methylmercury
Methylmercury
Methylmercury is an organometallic cation with the formula . It is a bioaccumulative environmental toxicant.-Structure:...

 (MeHg) because there are good correlations between environmental concentrations and snail tissue concentrations with respect to these toxic compounds.

Parasites

In its native Eurasian habitat, the faucet snail is host to many different species of digeneans, cercariae, metacercariae, cysticercoids, and other parasites.
  • As 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 Prosthogonimus ovatus
  • As an intermediate host for Sphaeridiotrema globulus
  • As first intermediate hosts and as second intermediate host for Cyanthocotyle bushiensis.
  • As second intermediate host for Echinostoma revolutum
    Echinostoma revolutum
    Echinostoma revolutum is a fluke that can be a parasite in humans. It causes the disease echinostomiasis.- Distribution :Echinostoma revolutum is the most widely distributed species of all 20 Echinostomatidae species and it is found from Asia and Oceania to Europe and the Americas.Echinostomiasis...

  • As intermediate host for Syngamus trachea
  • Capillariidae, probably Capillaria obsignata
  • Bithynia tenataculata is a suspected intermediate host for Leyogonimus polyoon

Other interspecific relationship

Natural dispersal of this snail is known to occur by passive transport in birds.

Bithynia tentaculata is capable of detecting the presence of molluscivorous leeches through chemoreception and of closing its 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...

to avoid predation.

External links & further reading

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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