The cylindrical lioplax,

scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Lioplax cyclostomaformis'', 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 ...

freshwater snail Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...

with

gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

s and an operculum, an aquatic

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

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 Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Viviparidae Viviparidae, sometimes known as the river snails or mystery snails, are a family of large operculate freshwater snails, aquatic gastropod mollusks. This family is classified in the informal group Architaenioglossa according to the taxonomy of ...

. This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

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 ou ...

is elongate, reaching about 28 millimeters (mm) (1.1 inches (in)) in length. Shell color is light to dark olivaceous-green externally, and bluish inside of the

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 opt ...

(shell opening). The cylindrical lioplax is distinguished from other viviparid (eggs hatch internally and the young are born as juveniles) snails in the

Mobile River The Mobile River is located in southern Alabama in the United States. Formed out of the confluence of the Tombigbee and Alabama rivers, the approximately river drains an area of of Alabama, with a watershed extending into Mississippi, Georg ...

Basin by the number of

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 ...

, and differences in size, sculpture, microsculpture, and

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 are ...

angle.

Distribution

This species is

to the

. No other species of lioplax snails are known to occur in the

Basin (see Clench and Turner, 1955Clench, W.J. and R.D. Turner. 1955. ''The North American genus Lioplax in the Family Viviparidae''. Occasional Papers on Mollusks. 2(19):1-20. for a more detailed description). Collection records for the cylindrical lioplax exist from the

Alabama River The Alabama River, in the U.S. state of Alabama, is formed by the Tallapoosa and Coosa rivers, which unite about north of Montgomery, near the town of Wetumpka. The river flows west to Selma, then southwest until, about from Mobile, it un ...

(Dallas County, Alabama),

Black Warrior River The Black Warrior River is a waterway in west-central Alabama in the southeastern United States. The river rises in the extreme southern edges of the Appalachian Highlands and flows 178 miles (286 km) to the Tombigbee River, of which the Bl ...

(Jefferson County, Alabama) and tributaries ( Prairie Creek, Marengo County, Alabama; Valley Creek, Jefferson County, Alabama);

Coosa River The Coosa River is a tributary of the Alabama River in the U.S. states of Alabama and Georgia. The river is about long.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 27, 2011 ...

(Shelby, Elmore counties, Alabama) and tributaries ( Oothcalooga Creek, Bartow County, Georgia; CoahuIla Creek, Whitfield County, Georgia; Annuchee Creek, Floyd County, Georgia;

Little Wills Creek Little Wills Creek is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed August 15, 2011 tributary of Wills Creek in Bedford County, Pennsylvania, in the United States.Gertler, Edward. '' ...

, Etowah County, Alabama;

Choccolocco Creek The Choccolocco Creek is one of two main tributaries of the Coosa River in central Alabama. The watershed of the creek comprises 246,000 acres (376 mi2) of drainage area. The waterway runs through the Choccolocco State Forest,Yellowleaf Creek, Shelby County, Alabama); and the

Cahaba River The Cahaba River is the longest substantially free-flowing river in Alabama and is among the most scenic and biologically diverse rivers in the United States. It is a major tributary of the Alabama River and part of the larger Mobile River basin. ...

(Bibb, Shelby counties, Alabama) and its tributary,

Little Cahaba River Little is a synonym for small size and may refer to: Arts and entertainment * ''Little'' (album), 1990 debut album of Vic Chesnutt * ''Little'' (film), 2019 American comedy film *The Littles, a series of children's novels by American author John P ...

(Jefferson County, Alabama). A single collection of this species has also been reported from the

Tensas River The Tensas River is a river in Louisiana in the United States. The river, known as Tensas Bayou in its upper reaches, begins in East Carroll Parish in the northeast corner of the state and runs roughly southwest for U.S. Geological Survey. Nationa ...

, Madison Parish, Louisiana; however, there are no previous or subsequent records outside of the Alabama-Coosa system, and searches of the Tensas River in Louisiana by Service biologists (1995) and others (Vidrine, 1996) have found no evidence of the species or its typical habitat. The cylindrical lioplax is currently known only from approximately 24 kilometers (km) (15 miles (mi)) of the Cahaba River above the Fall Line in Shelby and Bibb counties, Alabama.Bogan, A.E. and J.M. Pierson. 1993b. Survey of the aquatic gastropods of the Cahaba River Basin, Alabama: 1992. Alabama Natural Heritage Program. Contract Number 1922. Survey efforts by Davis failed to locate this snail in the Coosa or Alabama rivers, and more recent survey efforts have also failed to relocate the species at historic localities in the Alabama, Black Warrior, Little Cahaba, and Coosa rivers and their tributaries. It is listed as endangered in the

United States Fish and Wildlife Service list of endangered species This is a list of the bird and mammal species and subspecies described as endangered by the United States Fish and Wildlife Service. It contains species and subspecies not only in the U.S. and its territories, but also those only found in other par ...

since October 28, 1998 (according to report 63FR57619).

Ecology

Little is known of the biology or life history of the cylindrical lioplax.

Habitat

Habitat for the cylindrical lioplax is unusual for the genus, as well as for other genera of viviparid snails. It lives in isolated

mud A MUD (; originally multi-user dungeon, with later variants multi-user dimension and multi-user domain) is a Multiplayer video game, multiplayer Time-keeping systems in games#Real-time, real-time virtual world, usually Text-based game, text-bas ...

deposits found under large rocks in the rapid flowing sections of stream and river shoals. Other lioplax species are usually found along the margins of rivers in exposed muddy substrates.

Feeding habits

It is believed to brood its young and filter-feed, as do other members of the Viviparidae.

Life cycle

Life spans have been reported from 3 to 11 years in various species of Viviparidae.

References

This article incorporates public domain text (a

public domain The public domain (PD) consists of all the creative work A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...

work of the United States Government A work of the United States government, is defined by the United States copyright law, as "a work prepared by an officer or employee of the United States Government as part of that person's official duties." "A 'work of the United States Governmen ...

) from the reference.

U.S. Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with oth ...

. 2005
Recovery Plan for 6 Mobile River Basin Aquatic Snails
U.S. Fish and Wildlife Service, Jackson, Mississippi. 46 pp., page 3-4. {{Taxonbar, from=Q3142730 Viviparidae Molluscs of the United States Taxonomy articles created by Polbot ESA endangered species