Viviparus georgianus
Encyclopedia
Viviparus georgianus, common name
the banded mystery snail, is a species
of large freshwater snail
with gill
s and an operculum
, an aquatic
gastropod mollusk in the family Viviparidae
.
This snail is native to North America
. The specific epithet georgianus is a reference to the southern State of Georgia
, where the type locality is situated.
in 1834.
Lea's original text (the type description) reads as follows:
, with 4–5 whorls
separated by distinct sutures. The outer lip of the shell is quite thin and the overall coloration is yellow-green. There are abundant rows of hairs with distinctly hooked ends and ridges on the periostracum
. The umbilicus is narrow or not apparent, and the operculum
is round to oval, with concentric circular markings that radiate from an off-centre origin located towards the top left.
There are always 4 darkly pigmented bands that wrap around the shell spirally, but these are sometimes only visible from the inside of the shell.
One-year old snails are 12–17 mm high; at 2 years, 17–21 mm high; and at 3 years, 21–30 mm high. The maximum height is 45 mm.
it may even be better adapted than the introduced species Bithynia tentaculata
to such habitats.
Individuals are generally found in a range of habitats, including: regions with silt and mud substrate; communities dominated by diatom
s and filamentous algae
(not blue-green algae); shallow waters with sand or gravel substrate; soft and hard water; water with pH
between 6.3 and 8.5; freshwater habitats only; river reaches more than meanders.
Viviparus georgianus breeds and lives in shallow waters, often amongst macrophytes, in spring to fall, then moves out to deeper areas in the fall in order to overwinter away from shore. In more open waters, fall migration begins earlier than in smaller lakes and ponds. Most growth generally occurs when waters become warmer in spring and summer, although reduced growth continues in winter.
(it has two distinct sexes), iteroparous (reproducing more than once in a lifetime) and ovoviviparous, laying eggs singly in albumen-filled capsules. Females generally brood eggs for 9–10 months. Fecundity is generally between 4 and 81 young per female, but on average is closer to 11 young/female. Females can brood more than one batch of young at a time, and the number of young in one brood is positively related to the size of the female. Reproductive females are usually larger than 16 mm. Female banded mystery snails live 28 – 48 and males live 18 – 36 months.
detritivore
. Because of this, it can be used as a bioindicator
of sediment contamination
by oil and fertilizer, because its growth, survival and histology are significantly affected by the ingestion of contaminated sediments.
This species grazes on diatom
clusters found on silt and mud substrates, but it may also require the ingestion of some grit, in order to be able to break down algae.
The banded mystery snail often lives at high densities, sometimes up to around 864/m².
ns, annelid
s, and chironomid larvae.
and the Gulf of Mexico
primarily in south central Florida, Georgia
, Alabama
and north, mainly in the Mississippi River system, to Illinois
and northwestern Indiana
. Massachusetts
, Indiana and Connecticut
are probably some of the states marking the northern limit of this species’ native range.
A recent study found that Viviparus georgianus is in fact not one species, but a species complex
in North America. It was determined that Viviparus limi is native to the Ochlockonee River
and southwestern Georgia, while Viviparus goodrichi lives in the Florida panhandle and southwestern Georgia, and Viviparus georgianus defined sensu stricto is found in eastern and southern Florida as well as the Altamaha River in Georgia.
Other populations in the Altamaha, Mississippi and St. Lawrence River basins have not been studied yet with respect to their specific genetic make-up, and so they are simply named as being part of the Viviparus georgianus species complex.
, Michigan
, Wisconsin
, Virginia
, Pennsylvania
, New York
, New Jersey
, New England
, as well as Quebec
and Ontario
in Canada.
In the Mid-Atlantic Region it is found in the Niagara River
, Erie Canal
, Hudson River
drainage in New York, and possibly Lake Champlain
. It is established in the Chesapeake Bay
, Maryland.
In the Great Lakes Region: The first record of this introduced species in the Great Lakes basin is from the Hudson River
drainage, connected to the Erie Canal
and Mohawk River
, in 1867. It was later reported from the Lake Michigan
watershed by 1906 and Lake Erie
by 1914. Other records are from 1931 near Buffalo
, Lake Erie and the Niagara River
. The New York State Museum
has records from the 1950s and 1960s from 11 counties Mackie et al. (1980) list this species as recorded from Lake Huron
, but they do not give the date of establishment, or any references.
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 banded mystery snail, 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 large 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 Viviparidae
Viviparidae
Viviparidae, sometimes known as the river snails or mystery snails, are a family of large operculate freshwater snails, aquatic gastropod mollusks....
.
This snail is native to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. The specific epithet georgianus is a reference to the southern State of Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
, where the type locality is situated.
Original description
Viviparus georgianus was originally discovered and described (under the name Paludina georgiana) by Isaac LeaIsaac Lea
Isaac Lea was an American conchologist, geologist, and businessman, who was born in Wilmington, Delaware.-Life:...
in 1834.
Lea's original text (the type description) reads as follows:
Shell description
Viviparus georgianus has a relatively globose, dextral shellGastropod 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...
, with 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...
separated by distinct sutures. The outer lip of the shell is quite thin and the overall coloration is yellow-green. There are abundant rows of hairs with distinctly hooked ends and ridges on the periostracum
Periostracum
The periostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled animals, including mollusks and brachiopods. Among mollusks it is primarily seen in snails and clams, i.e. in bivalves and gastropods, but it is also found in cephalopods such as the...
. The umbilicus is narrow or not apparent, and 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...
is round to oval, with concentric circular markings that radiate from an off-centre origin located towards the top left.
There are always 4 darkly pigmented bands that wrap around the shell spirally, but these are sometimes only visible from the inside of the shell.
One-year old snails are 12–17 mm high; at 2 years, 17–21 mm high; and at 3 years, 21–30 mm high. The maximum height is 45 mm.
Habitat
This snail is found in lakes and slow-moving rivers with mud bottoms. The species thrives in eutrophic lentic environments such as lakes, ponds and some low-flow streams. It is usually absent from larger, faster flowing rivers; however, it is able to survive conditions of high water velocity in the St. Lawrence River, and in the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
it may even be better adapted than the introduced species Bithynia tentaculata
Bithynia tentaculata
Bithynia tentaculata, common names the mud bithynia or common bithynia, or faucet snail is a relatively small species of freshwater snail with gills and an operculum, an aquatic prosobranch gastropod mollusk in the family Bithyniidae....
to such habitats.
Individuals are generally found in a range of habitats, including: regions with silt and mud substrate; communities dominated by diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
s and filamentous 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...
(not blue-green algae); shallow waters with sand or gravel substrate; soft and hard water; water 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...
between 6.3 and 8.5; freshwater habitats only; river reaches more than meanders.
Viviparus georgianus breeds and lives in shallow waters, often amongst macrophytes, in spring to fall, then moves out to deeper areas in the fall in order to overwinter away from shore. In more open waters, fall migration begins earlier than in smaller lakes and ponds. Most growth generally occurs when waters become warmer in spring and summer, although reduced growth continues in winter.
Life cycle
It is dioeciousDioecious
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 distinct sexes), iteroparous (reproducing more than once in a lifetime) and ovoviviparous, laying eggs singly in albumen-filled capsules. Females generally brood eggs for 9–10 months. Fecundity is generally between 4 and 81 young per female, but on average is closer to 11 young/female. Females can brood more than one batch of young at a time, and the number of young in one brood is positively related to the size of the female. Reproductive females are usually larger than 16 mm. Female banded mystery snails live 28 – 48 and males live 18 – 36 months.
Feeding habits
Viviparus georgianus is known to be a facultative or even obligate filter-feedingFilter 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,...
detritivore
Detritivore
Detritivores, also known as detritophages or detritus feeders or detritus eaters or saprophages, are heterotrophs that obtain nutrients by consuming detritus . By doing so, they contribute to decomposition and the nutrient cycles...
. Because of this, it can be used as a bioindicator
Bioindicator
Biological indicators are species used to monitor the health of an environment or ecosystem. They are any biological species or group of species whose function, population, or status can be used to determine ecosystem or environmental integrity. An example of such a group are the copepods and other...
of sediment contamination
Contamination
Contamination is the presence of a minor and unwanted constituent in material, physical body, natural environment, at a workplace, etc.-Specifics:"Contamination" also has more specific meanings in science:...
by oil and fertilizer, because its growth, survival and histology are significantly affected by the ingestion of contaminated sediments.
This species grazes on diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
clusters found on silt and mud substrates, but it may also require the ingestion of some grit, in order to be able to break down algae.
The banded mystery snail often lives at high densities, sometimes up to around 864/m².
Parasites
This snail is host to many parasites in its native habitat, including cercaria, metacercaria, ciliated protozoaProtozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
ns, annelid
Annelid
The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...
s, and chironomid larvae.
Indigenous distribution
The banded mystery snail is native to North America, generally found from the northeastern United States to FloridaFlorida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
and the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
primarily in south central Florida, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
, Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...
and north, mainly in the Mississippi River system, to Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
and northwestern Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
. Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
, Indiana and Connecticut
Connecticut
Connecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...
are probably some of the states marking the northern limit of this species’ native range.
A recent study found that Viviparus georgianus is in fact not one species, but a species complex
Species complex
A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...
in North America. It was determined that Viviparus limi is native to the Ochlockonee River
Ochlockonee River
The Ochlockonee River is a fast running river originating in Georgia and flowing for before terminating in Florida.- Background :The Ochlockonee originates south of the town of Sylvester in Worth County in southwest Georgia emptying into Ochlockonee Bay, then into Apalachee Bay, in Florida...
and southwestern Georgia, while Viviparus goodrichi lives in the Florida panhandle and southwestern Georgia, and Viviparus georgianus defined sensu stricto is found in eastern and southern Florida as well as the Altamaha River in Georgia.
Other populations in the Altamaha, Mississippi and St. Lawrence River basins have not been studied yet with respect to their specific genetic make-up, and so they are simply named as being part of the Viviparus georgianus species complex.
Nonindigenous distribution
This species has invaded the northern part of the United States: OhioOhio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
, Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
, 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...
, Virginia
Virginia
The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there...
, 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...
, 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...
, New Jersey
New Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
, New England
New England
New England is a region in the northeastern corner of the United States consisting of the six states of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island, and Connecticut...
, as well as 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 Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
in Canada.
In the Mid-Atlantic Region it is found in the Niagara River
Niagara River
The Niagara River flows north from Lake Erie to Lake Ontario. It forms part of the border between the Province of Ontario in Canada and New York State in the United States. There are differing theories as to the origin of the name of the river...
, Erie Canal
Erie Canal
The Erie Canal is a waterway in New York that runs about from Albany, New York, on the Hudson River to Buffalo, New York, at Lake Erie, completing a navigable water route from the Atlantic Ocean to the Great Lakes. The canal contains 36 locks and encompasses a total elevation differential of...
, 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...
drainage in New York, and possibly 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...
. It is established in the 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.
In the Great Lakes Region: The first record of this introduced species in the Great Lakes basin is from 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...
drainage, connected to the Erie Canal
Erie Canal
The Erie Canal is a waterway in New York that runs about from Albany, New York, on the Hudson River to Buffalo, New York, at Lake Erie, completing a navigable water route from the Atlantic Ocean to the Great Lakes. The canal contains 36 locks and encompasses a total elevation differential of...
and Mohawk River
Mohawk River
The Mohawk River is a river in the U.S. state of New York. It is the largest tributary of the Hudson River. The Mohawk flows into the Hudson in the Capital District, a few miles north of the city of Albany. The river is named for the Mohawk Nation of the Iroquois Confederacy...
, in 1867. It was later reported from the 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...
watershed by 1906 and 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...
by 1914. Other records are from 1931 near Buffalo
Buffalo, New York
Buffalo is the second most populous city in the state of New York, after New York City. Located in Western New York on the eastern shores of Lake Erie and at the head of the Niagara River across from Fort Erie, Ontario, Buffalo is the seat of Erie County and the principal city of the...
, Lake Erie and the Niagara River
Niagara River
The Niagara River flows north from Lake Erie to Lake Ontario. It forms part of the border between the Province of Ontario in Canada and New York State in the United States. There are differing theories as to the origin of the name of the river...
. The New York State Museum
New York State Museum
The New York State Museum is a research-backed institution in Albany, New York, United States. It is located on Madison Avenue, attached to the south side of the Empire State Plaza, facing onto the plaza and towards the New York State Capitol...
has records from the 1950s and 1960s from 11 counties Mackie et al. (1980) list this species as 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 they do not give the date of establishment, or any references.