The Tumbling Creek cavesnail (''Antrobia culveri'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of freshwater cave snail with

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, 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 r ...

s and an operculum, an aquatic

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

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'' 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, inv ...

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

Taney County, Missouri Taney County is a county 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 Micropolitan Statistical Area. Taney County was ...

, US

Taxonomy

The Tumbling Creek cavesnail was described as a new species by Leslie Hubricht in 1971, from specimens taken by David Culver, Thomas Aley, and Hubricht in 1969 and 1970. ''Antrobia culveri'' is the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

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'', 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, and Oklahoma, as well as a small area in the southeastern corner of Kansas. The Ozarks cov ...

in Missouri and

Arkansas Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...

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 Science Biology * Seashell, a hard outer layer of a marine ani ...

is small, conical, well-rounded and pale-yellow with about 3.5 whorls. 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, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

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 only 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 foun ...

species, part of the wildlife of Missouri, United States. Its distribution is restricted to a single cave stream in Tumbling Creek Cave, in Taney County, in southwestern

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') 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 border ...

.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 Caves or caverns are natural voids under the Earth's Planetary surface, surface. Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance undergrou ...

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 environmen ...

. 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 ) is the accumulated excrement of seabirds or bats. Guano is a highly effective fertiliser due to the high content of nitrogen, phosphate, and potassium, all key nutrients essential for plant growth. Guano was also, to a le ...

, 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 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 Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

and

water pollution Water pollution (or aquatic pollution) is the contamination of Body of water, water bodies, with a negative impact on their uses. It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and ...

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 to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...

work of the United States Government A work of the United States government is defined by the United States copyright law of 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".: ...

) 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 government gazette, official journal of the federal government of the United States that contains government agency rules, proposed rules, and public notices. It is published every wee ...

'' 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'', 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 Endemic fauna of Missouri Endemic molluscs of the United States