Elimia virginica
Encyclopedia
Elimia virginica, common name
s the Piedmont elimia or Virginia river snail, is a species of freshwater snail
with an operculum
, an aquatic gastropod mollusk in the family Pleuroceridae
.
. The operculum
in this species is proteinaceous, corneous, and paucispiral and is withdrawn when the snail is active.
The shells are dextral and have a very high and narrow spire
, with little space in the suture
(the incisions between the whorls
). This species has two distinct shell morphologies, one smooth and one lirate (i.e. finely lined or grooved).
Specimens of this species often vary in coloration: in general, Elimia virginica is yellow to chestnut in hue, but it sometimes has 2 darker brown spiral bands. Juveniles (snails with an aperture
height of no more than 7 mm) display the banding more frequently than adults.
Shells of specimens of Elimia virginica from New York State and the Connecticut River
range from 27 to 33 mm high, with an aperture height of 9–12 mm.
There is known 4 nucleotide
sequences and 1 protein
sequence of Elimia virginica recently in 2008.
east of the continental divide. The species occurs in large Atlantic coast rivers in eastern North America, from Massachusetts
to Virginia
. The northeastern limit of the native range of the species is the lower Connecticut River
.
The distribution of this species is shrinking in the native Connecticut River, and it is considered rare in Connecticut. Its conservation status in the Connecticut River Watershed is W1 ("a rare species, with 20 or fewer known occurrences in the watershed states").
Conservation status of Elimia virginica is according to NatureServe
like this:
to the Lake Ontario
drainage.
The first record of this species in the Great Lakes
drainage dates from around 1856-1860, when it was found in the Erie Canal
near Mohawk
, New York State. Populations later increased throughout the canal in the late 19th century, and reached Buffalo
, at the mouth of Lake Erie
. In the 1960s, this species was recorded from Oneida Lake
in New York State.
This species is considered established in the Lake Ontario drainage. However, this species, although introduced to the Lake Ontario drainage, has been largely out-competed by another introduced snail, this one from the Palaearctic ecozone, Bithynia tentaculata
. Thus Elimia virginica is now virtually absent from the Oswego
drainage, and is possibly very reduced in abundance in other localities where it was introduced, due to such interspecific competition
.
There are currently no known impacts caused by introduction of this species to other water bodies.
al environments, in riffles or shoals with rock or sand substrate, and especially frequently on rocks in slower areas of medium size reaches.) Elimia virginica usually inhabits slow to medium velocity rivers and streams with firm and clean gravel, cobble and rock substrate. Pleurocerids in general are sensitive to abiotic stress
es, and Elimia virginica is not tolerant to silt
ation.
In Connecticut, Elimia virginica is at the edge of its range
, and is most likely limited to hard water
habitats only. During collections made in the Connecticut River
, the snail was found to inhabit regions with water temperatures up to 27.5 °C, dissolved oxygen between 7 and 14 ppm
, CaCO3
concentration from 42-160 ppm, pH
from 7.6-9.0 and CO2
concentration from 0-10 ppm. However, at some of these sites, population abundance was very low and/or decreasing, especially in conditions of high water temperature and alkalinity
.
. It lays its eggs from spring to summer, in particular in June and July.
This species, unlike softer shelled physid
snails, grows very slowly, and has the lowest intrinsic rate of increase (this means that populations grow very slowly), along with Leptoxis carinata
, in this environment.
Individuals of this species are often sexually mature within one year; and can live 5 years.
, the shell of Elimia virginica is often used as substrate
by epizootic
algae
and the entoproct
Urnatella gracilis.
A short study in the Potomac River
, Virginia, found that the snail has a very strong shell that is adapted to withstand predation by such predators as crayfish
and duck
s. However, there is an evolutionary trade-off
between predator defense and rapid growth and reproduction amongst snail populations found in this river.
There is recent evidence for hybridisation (the process of creating intermediate forms called hybrids during interspecific breeding) and introgression
between Elimia virginica and Elimia livescens
amongst populations brought into contact due to the opening of the Erie Canal. These two species were formerly completely geographically isolated during glaciation by the Alleghenian Divide: the former was only found in Atlantic Slope drainages, while the latter was only found in Interior Basin drainages. Hybridization and introgression of this kind can put the genetic integrity of a species at severe risk, especially when the population is already small.
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...
s the Piedmont elimia or Virginia river snail, is a species of freshwater snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
with 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 gastropod mollusk in the family Pleuroceridae
Pleuroceridae
Pleuroceridae, common name pleurocerids, is a family of small to medium-sized freshwater snails, aquatic gilled gastropod mollusks in the superfamily Cerithioidea.These snails have an operculum and typically a robust high-spired shell....
.
Shell description
Elimia virginica belongs to the family Pleuroceridae, a group of snails that have thick, elongated shellsGastropod 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...
. 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...
in this species is proteinaceous, corneous, and paucispiral and is withdrawn when the snail is active.
The shells are dextral and have a very high and narrow 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...
, with little space in the suture
Suture (anatomical)
In anatomy, a suture is a fairly rigid joint between two or more hard elements of an animal, with or without significant overlap of the elements....
(the incisions between the 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...
). This species has two distinct shell morphologies, one smooth and one lirate (i.e. finely lined or grooved).
Specimens of this species often vary in coloration: in general, Elimia virginica is yellow to chestnut in hue, but it sometimes has 2 darker brown spiral bands. Juveniles (snails with an 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....
height of no more than 7 mm) display the banding more frequently than adults.
Shells of specimens of Elimia virginica from New York State and the Connecticut River
Connecticut River
The Connecticut River is the largest and longest river in New England, and also an American Heritage River. It flows roughly south, starting from the Fourth Connecticut Lake in New Hampshire. After flowing through the remaining Connecticut Lakes and Lake Francis, it defines the border between the...
range from 27 to 33 mm high, with an aperture height of 9–12 mm.
Anatomy
It is easy to distinguish the female of this species in whole animals, because of the presence of the external genital sinus.There is known 4 nucleotide
Nucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
sequences and 1 protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
sequence of Elimia virginica recently in 2008.
Indigenous distribution
Elimia virginica is native to the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
east of the continental divide. The species occurs in large Atlantic coast rivers in eastern North America, from 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...
to 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...
. The northeastern limit of the native range of the species is the lower Connecticut River
Connecticut River
The Connecticut River is the largest and longest river in New England, and also an American Heritage River. It flows roughly south, starting from the Fourth Connecticut Lake in New Hampshire. After flowing through the remaining Connecticut Lakes and Lake Francis, it defines the border between the...
.
The distribution of this species is shrinking in the native Connecticut River, and it is considered rare in Connecticut. Its conservation status in the Connecticut River Watershed is W1 ("a rare species, with 20 or fewer known occurrences in the watershed states").
Conservation status of Elimia virginica is according to NatureServe
NatureServe
NatureServe is a non-profit conservation organization whose mission is to provide the scientific basis for effective conservation action. NatureServe and its network of natural heritage programs are the leading source for information about rare and endangered species and threatened ecosystems in...
like this:
- United States of America - secure.
- Massachusetts - presumed extirpated.
- Connecticut - critically imperiled.
- New York - vulnerable.
- New Jersey - unranked.
- Pennsylvania - secure.
- Virginia - apparently secure.
- North Carolina - unrankable.
Nonindigenous distribution
The nonindigenous distribution of Elimia virginica includes another area in the United States: it migrated from the Atlantic drainage through the Erie CanalErie 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...
to the 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...
drainage.
The first record of this 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...
drainage dates from around 1856-1860, when it was found in 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...
near Mohawk
Mohawk, Herkimer County, New York
----Mohawk is a village in Herkimer County, New York, United States. The population was 2,660 at the 2000 census. The village was named after the adjacent river....
, New York State. Populations later increased throughout the canal in the late 19th century, and reached 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...
, at the mouth of 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...
. In the 1960s, this species was recorded from 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 New York State.
This species is considered established in the Lake Ontario drainage. However, this species, although introduced to the Lake Ontario drainage, has been largely out-competed by another introduced snail, this one from the Palaearctic ecozone, 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....
. Thus Elimia virginica is now virtually absent from the Oswego
Oswego River (New York)
The Oswego River is a river in upstate New York in the United States. This river is the second-largest river flowing into Lake Ontario. James Fenimore Cooper’s novel The Pathfinder, or The Inland Sea is set in the Oswego River valley...
drainage, and is possibly very reduced in abundance in other localities where it was introduced, due to such interspecific competition
Interspecific competition
Interspecific competition, in ecology, is a form of competition in which individuals of different species compete for the same resource in an ecosystem...
.
There are currently no known impacts caused by introduction of this species to other water bodies.
Habitat
Elimia virginica is found in freshwater rivers and streams with cobble bottoms and boulders. (Pleurocerids are usually found in lotic erosionErosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
al environments, in riffles or shoals with rock or sand substrate, and especially frequently on rocks in slower areas of medium size reaches.) Elimia virginica usually inhabits slow to medium velocity rivers and streams with firm and clean gravel, cobble and rock substrate. Pleurocerids in general are sensitive to abiotic stress
Abiotic stress
Abiotic stress is defined as the negative impact of non-living factors on the living organisms in a specific environment. The non-living variable must influence the environment beyond its normal range of variation to adversely affect the population performance or individual physiology of the...
es, and Elimia virginica is not tolerant to silt
Silt
Silt is granular material of a size somewhere between sand and clay whose mineral origin is quartz and feldspar. Silt may occur as a soil or as suspended sediment in a surface water body...
ation.
In Connecticut, Elimia virginica is at the edge of its range
Range (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
, and is most likely limited to hard water
Hard water
Hard water is water that has high mineral content . Hard water has high concentrations of Ca2+ and Mg2+ ions. Hard water is generally not harmful to one's health but can pose serious problems in industrial settings, where water hardness is monitored to avoid costly breakdowns in boilers, cooling...
habitats only. During collections made in the Connecticut River
Connecticut River
The Connecticut River is the largest and longest river in New England, and also an American Heritage River. It flows roughly south, starting from the Fourth Connecticut Lake in New Hampshire. After flowing through the remaining Connecticut Lakes and Lake Francis, it defines the border between the...
, the snail was found to inhabit regions with water temperatures up to 27.5 °C, dissolved oxygen between 7 and 14 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...
, CaCO3
Calcium carbonate
Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks in all parts of the world, and is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime,...
concentration from 42-160 ppm, 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...
from 7.6-9.0 and CO2
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
concentration from 0-10 ppm. However, at some of these sites, population abundance was very low and/or decreasing, especially in conditions of high water temperature and alkalinity
Alkalinity
Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
.
Life cycle
Elimia virginica 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 lays its eggs from spring to summer, in particular in June and July.
This species, unlike softer shelled physid
Physidae
Physidae, common name bladder snails, are a monophyletic taxonomic family of small freshwater snails, aquatic pulmonate gastropod molluscs in the clade Hygrophila....
snails, grows very slowly, and has the lowest intrinsic rate of increase (this means that populations grow very slowly), along with Leptoxis carinata
Leptoxis carinata
Leptoxis carinata, common name the crested mudalia, is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.- Shell description :Leptoxis carinata has a shell and an operculum....
, in this environment.
Individuals of this species are often sexually mature within one year; and can live 5 years.
Other interspecific relationships
In the Connecticut RiverConnecticut River
The Connecticut River is the largest and longest river in New England, and also an American Heritage River. It flows roughly south, starting from the Fourth Connecticut Lake in New Hampshire. After flowing through the remaining Connecticut Lakes and Lake Francis, it defines the border between the...
, the shell of Elimia virginica is often used as substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
by epizootic
Epizootic
In epizoology, an epizootic is a disease that appears as new cases in a given animal population, during a given period, at a rate that substantially exceeds what is "expected" based on recent experience . Epidemic is the analogous term applied to human populations...
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 the entoproct
Entoprocta
Entoprocta, whose name means "anus inside", is a phylum of mostly sessile aquatic animals, ranging from long. Mature individuals are goblet-shaped, on relatively long stalks. They have a "crown" of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and...
Urnatella gracilis.
A short study in the 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...
, Virginia, found that the snail has a very strong shell that is adapted to withstand predation by such predators as crayfish
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...
and duck
Duck
Duck is the common name for a large number of species in the Anatidae family of birds, which also includes swans and geese. The ducks are divided among several subfamilies in the Anatidae family; they do not represent a monophyletic group but a form taxon, since swans and geese are not considered...
s. However, there is an evolutionary trade-off
Trade-off
A trade-off is a situation that involves losing one quality or aspect of something in return for gaining another quality or aspect...
between predator defense and rapid growth and reproduction amongst snail populations found in this river.
There is recent evidence for hybridisation (the process of creating intermediate forms called hybrids during interspecific breeding) and introgression
Introgression
Introgression, also known as introgressive hybridization, in genetics is the movement of a gene from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species...
between Elimia virginica and Elimia livescens
Elimia livescens
Elimia livescens, common name the liver elimia, is a species of freshwater snail with an operculum, an aquatic gastropod mollusk in the family Pleuroceridae.- Shell description :...
amongst populations brought into contact due to the opening of the Erie Canal. These two species were formerly completely geographically isolated during glaciation by the Alleghenian Divide: the former was only found in Atlantic Slope drainages, while the latter was only found in Interior Basin drainages. Hybridization and introgression of this kind can put the genetic integrity of a species at severe risk, especially when the population is already small.
Further reading
- Snail, Piedmont elimia (Elimia virginica) Toxicity Studies
- Photo of a live Elimia virginica
- Tomba A. M. 2008. Environmental variation and distribution patterns of freshwater snails (Family Pleuroceridae) and their trematode parasites in the rappahannock watershed. The Nabs 56th Annual Meeting (25–28 May 2008).
