The Tumbling Creek cavesnail (''Antrobia culveri'') 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 ...

of freshwater cave snail 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

Amnicolidae Amnicolidae is a family of small freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the superfamily Rissooidea. This family is in the clade Littorinimorpha (according to the taxonomy of the Gastropoda by Bouchet & ...

.Bouchet, P. (2014). Antrobia culveri Hubricht, 1971. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=729787 on 2015-02-19 ''Antrobia culveri'' is the only species in the genus ''Antrobia''.Kabat A. R. & Hershler R. (1993). "The prosobranch snail family Hydrobiidae (Gastropoda: Rissooidea): review of classification and supraspecific taxa". ''

Smithsonian Contributions to Zoology The Smithsonian Contributions and Studies Series is a collection of serial periodical publications produced by the Smithsonian Institution, detailing advances in various scientific and societal fields to which the Smithsonian Institution has made c ...

'' 547: 1-94
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This is an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

. The common name refers to Tumbling Creek Cave, a National Natural Landmark, in

Taney County, Missouri Taney County is a county located in the southwestern portion of the U.S. state of Missouri. As of the 2020 census, the population was 56,066. Its county seat is Forsyth. It is included in the Branson, Missouri, Micropolitan Statistical Area. ...

, US

Taxonomy

The Tumbling Creek cavesnail was described as a new species by

Leslie Hubricht Leslie Hubricht (born 11 January 1908 in Los Angeles, California, died 16 September 2005 in Meridian, Mississippi) was an American biologist and malacologist. ''Antrobia culveri'' is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

for the genus '' Antrobia'', also described as new to science in 1971 by Hubricht. Hershler and Hubricht (1988) examined specimens of ''Antrobia culveri'' and confirmed the taxonomic placement of this species at that time in the subfamily Littoridininae. They also noted the similarity of the genus ''Antrobia'' to, but distinguished it from, the genus ''

Fontigens ''Fontigens'' is a genus of minute freshwater snails with an operculum, aquatic gastropod molluscs or micromolluscs in the family Hydrobiidae Hydrobiidae, commonly known as mud snails, is a large cosmopolitan family of very small freshw ...

'', which contains cave-adapted snails found in other caves and springs of the

Ozark Plateau The Ozarks, also known as the Ozark Mountains, Ozark Highlands or Ozark Plateau, is a physiographic region in the U.S. states of Missouri, Arkansas, Oklahoma and the extreme southeastern corner of Kansas. The Ozarks cover a significant porti ...

in Missouri and

Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...

Description

The Tumbling Creek cavesnail is a small, white, blind, aquatic snail. 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 o ...

is small, conical, well-rounded and pale-yellow with about 3.5

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 ...

. The dimensions of the type specimen are as follows: height 2.3 millimeters (mm) (0.09 inches); diameter 2.0 mm (0.08 in);

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 ...

height 1.2 mm (0.05 in); aperture diameter 1.1 mm (0.04 in).

Distribution

Map of Missouri highlighting Taney County

''Antrobia culveri'' is an

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 ...

species, part of the

wildlife of Missouri Missouri is home to a diversity of both flora and fauna. There is a large amount of fresh water present due to the Mississippi River, Missouri River, and Lake of the Ozarks, with numerous smaller tributary rivers, streams, and lakes. North of the ...

, United States. Its distribution is restricted to a single cave stream in Tumbling Creek Cave, in Taney County, in southwestern

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

.U.S. Fish and Wildlife Service. (2003). "Tumbling Creek Cavesnail Recovery Plan (''Antrobia culveri'')"]. U.S. Fish and Wildlife Service, Ft. Snelling, Minnesota. 97 pages
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Ecology

Habitat

This snail is an animal which lives in

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

s, thus it is a

troglobite A troglobite (or, formally, troglobiont) is an animal species, or population of a species, strictly bound to underground habitats, such as caves. These are separate from species that mainly live in above-ground habitats but are also able to live u ...

. In addition it is an aquatic troglobite, and animals who live in this specialized kind of habitat are known as stygobites or

stygofauna Stygofauna are any fauna that live in groundwater systems or aquifers, such as caves, fissures and vugs. Stygofauna and troglofauna are the two types of subterranean fauna (based on life-history). Both are associated with subterranean environments ...

. The Tumbling Creek cavesnail lives on the underside of rocks in areas of Tumbling Creek that have little or no silt. ''Antrobia culveri'' is using a solid rock bottom, and the species is usually observed on the undersurface of rocks and gravel of various sizes. Observations between March and August 2001 suggest that ''Antrobia culveri'' is now restricted to 23 m of available stream habitat or approximately 5 percent of the 457 meters of accessible suitable habitat. Species such as the Tumbling Creek cavesnail, which spend all of their life cycle in subterranean waters, are highly vulnerable to changes in the quality and quantity of that water.

Feeding habits

Although little is known regarding the biology of this cave snail, it is believed that the species feeds on aquatic microfauna (i.e., the microscopic, bacterial film or “biofilm" which does appear to be ingested by the cave snail). Because Tumbling Creek cavesnails are usually concentrated in those sections of Tumbling Creek Cave which are adjacent to large deposits of bat

guano Guano (Spanish from qu, wanu) is the accumulated excrement of seabirds or bats. As a manure, guano is a highly effective fertilizer due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. G ...

, it has been suggested that ''Antrobia culveri'' is indirectly dependent upon these deposits for food.

Life cycle

Life history aspects of this species, including its reproductive behavior, are unknown.

Conservation

The number of cave snails has significantly decreased over the past few decades, from an estimated 15,118 in 1973,Greenlee R. E. (1974). "Determination of the range of the Tumbling Creek cavesnail". '' Missouri Speleology'' 14(3): 9-11. to the point where only one individual was found within the survey areas during January 11, 2001 and April 22, 2003. A small population containing approximately 40 individuals does exist however in a small area upstream from the part of the creek that is regularly surveyed. Based on the decline of the Tumbling Creek cavesnail, it is listed as endangered at

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 August 14, 2002.U.S. Fish & Wildlife Service
"Species profile Tumbling Creek cavesnail (''Antrobia culveri'')"
Accessed 15 November 2008. Although the primary limiting factor of the population appears to be decreased

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

, due to increased

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

and

water pollution Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water ...

in the cave’s recharge area, scientific research is needed to confirm this hypothesis.

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

External links

* Wooley C. M. (September 22, 2003). "Approved Recovery Plan for the Tumbling Creek Cavesnail (''Antrobia culveri'')". ''

Federal Register The ''Federal Register'' (FR or sometimes Fed. Reg.) is the official journal of the federal government of the United States that contains government agency rules, proposed rules, and public notices. It is published every weekday, except on feder ...

'' 68(183): 55060-55061. (Federal Register Notice of Availability recovery plan.
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* (Page revised December 19, 2007)

ttp://www.fws.gov/midwest/endangered/Snails/tcca-fctsht.pdf PDF version* Hershler R. & Thompson F. G. (1992). "A Review of the Aquatic Gastropod Subfamily Cochliopinae (Prosobranchia: Hydrobiidae)". ''

Malacological Review Malacology is the branch of invertebrate zoology that deals with the study of the Mollusca (mollusks or molluscs), the second-largest phylum of animals in terms of described species after the arthropods. Mollusks include snails and slugs, clams, ...

'', Supplement 5: 1-140. pages 16–18. {{Taxonbar, from=Q3138132, from2=Q7991822 Amnicolidae Taney County, Missouri Gastropods described in 1971 Taxonomy articles created by Polbot ESA endangered species Cave snails