Cylindrical lioplax
Encyclopedia
The cylindrical lioplax, scientific name Lioplax cyclostomaformis, is a species
of freshwater snail
with gill
s and an operculum
, an aquatic
gastropod mollusk in the family
Viviparidae
.
This species is endemic to the United States
.
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
(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
Basin by the number of whorls
, and differences in size, sculpture, microsculpture, and spire
angle.
.
No other species of lioplax snails are known to occur in the Mobile River
Basin (see Clench and Turner, 1955 for a more detailed description).
Collection records for the cylindrical lioplax exist from the Alabama River
(Dallas County, Alabama), Black Warrior River
(Jefferson County, Alabama) and tributaries (Prairie Creek
, Marengo County, Alabama; Valley Creek
, Jefferson County, Alabama); Coosa River
(Shelby, Elmore counties, Alabama) and tributaries (Oothcalooga Creek, Bartow County, Georgia; CoahuIla Creek, Whitfield County, Georgia; Annuchee Creek, Floyd County, Georgia; Little Wills Creek
, Etowah County, Alabama; Choccolocco Creek, Talladega County, Alabama; Yellowleaf Creek, Shelby County, Alabama); and the Cahaba River
(Bibb, Shelby counties, Alabama) and its tributary, Little Cahaba River (Jefferson County, Alabama).
A single collection of this species has also been reported from the Tensas River
, 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. 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
since October 28, 1998 (accorrding to report 63FR57619).
mud
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.
, as do other members of the Viviparidae.
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...
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...
Viviparidae
Viviparidae
Viviparidae, sometimes known as the river snails or mystery snails, are a family of large operculate freshwater snails, aquatic gastropod mollusks....
.
This species is endemic to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Description
The 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...
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
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....
(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
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, Georgia, and Tennessee. Its drainage basin is the...
Basin by the number of 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 differences in size, sculpture, microsculpture, and 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...
angle.
Distribution
This species is endemic to the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
No other species of lioplax snails are known to occur in the Mobile River
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, Georgia, and Tennessee. Its drainage basin is the...
Basin (see Clench and Turner, 1955 for a more detailed description).
Collection records for the cylindrical lioplax exist from the Alabama River
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.The river flows west to Selma, then southwest until, about from Mobile, it unites with the Tombigbee, forming the Mobile and Tensaw rivers, which discharge into...
(Dallas County, Alabama), Black Warrior River
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 to the Tombigbee River, of which the Black Warrior is the primary tributary...
(Jefferson County, Alabama) and tributaries (Prairie Creek
Prairie Creek
Prairie Creek may refer to:* Prairie Creek, Arkansas* Prairie Creek, Florida in Alachua County, FL* Prairie Creek, Indiana* Prairie Creek Redwoods State Park, in California* Prairie Creek * Prairie Creek Township...
, Marengo County, Alabama; Valley Creek
Valley Creek
Valley Creek is a tributary of the Schuylkill River in eastern Chester County, Pennsylvania, United States, flowing through an area known as the Great Valley....
, Jefferson County, Alabama); Coosa River
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 altogether.The Coosa River is one of Alabama's most developed rivers...
(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
Little Wills Creek is a tributary of Wills Creek in Bedford County, Pennsylvania, in the United States.Little Wills Creek flows down a valley between the Allegheny Front and Wills Mountain, drawing most of its water from the Allegheny Plateau, and enters Wills Creek just below...
, Etowah County, Alabama; Choccolocco Creek, Talladega County, Alabama; Yellowleaf Creek, Shelby County, Alabama); and the Cahaba River
Cahaba River
The Cahaba River is the longest free-flowing river in Alabama and is among the most scenic and biologically diverse rivers in the United States. The Cahaba River 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 (Jefferson County, Alabama).
A single collection of this species has also been reported from the Tensas River
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 more or less in parallel with the Mississippi River...
, 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. 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
United States Fish and Wildlife Service list of endangered species
This list contains only the bird and mammal species described as endangered by the United States Fish and Wildlife Service. It contains species not only in the U.S. and its territories, but also species only found abroad. It does not contain fish, amphibians, reptiles, plants, or invertebrates,...
since October 28, 1998 (accorrding to report 63FR57619).
Habitat
Habitat for the cylindrical lioplax is unusual for the genus, as well as for other genera of viviparid snails. It lives in isolatedmud
Mud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
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-feedFilter 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,...
, as do other members of the Viviparidae.