Tumbling creek cavesnail
Encyclopedia
The Tumbling Creek cavesnail, Antrobia culveri, is a species
of freshwater cave snail
with gill
s and an operculum
, an aquatic
gastropod mollusk in the family Cochliopidae
.
Antrobia culveri is the only species in the genus Antrobia.
in 1971, from specimens taken by David Culver, Thomas Aley, and Hubricht in 1969 and 1970. Antrobia culveri is the type species
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 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 in Missouri and Arkansas
.
According to the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
this genus is in the subfamily Littoridininae within the family Cochliopidae
.
The shell
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 (in)); diameter 2.0 mm (0.08 in); aperture
height 1.2 mm (0.05 in); aperture diameter 1.1 mm (0.04 in).
Antrobia culveri is an endemic species, part of the wildlife of Missouri USA.
Its distribution is restricted to a single cave stream in Tumbling Creek Cave, in Taney County
, in southwestern Missouri
.
s, thus it is a troglobite
. In addition it is an aquatic troglobite, and animals who live in this specialized kind of habitat are known as stygobites or stygofauna
.
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.
, it has been suggested that Antrobia culveri is indirectly dependent upon these deposits for food.
since August 14, 2002.
Although the primary limiting factor of the population appears to be decreased water quality
, due to increased erosion
and water pollution
in the cave’s recharge area, scientific research is needed to confirm this hypothesis.
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 cave 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 Cochliopidae
Cochliopidae
Cochliopidae is a family of small freshwater snails with gills and an operculum, aquatic gastropod mollusks.This family is in the superfamily Rissooidea and in the clade Littorinimorpha ....
.
Antrobia culveri is the only species in the genus Antrobia.
Taxonomy
The Tumbling Creek cavesnail was described as a new species by Leslie HubrichtLeslie Hubricht
Leslie Hubricht was an American biologist and malacologist.If he had lived in a previous century, Hubricht would have been called a "gentleman naturalist"...
in 1971, from specimens taken by David Culver, Thomas Aley, and Hubricht in 1969 and 1970. Antrobia culveri is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
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 in the subfamily Littoridininae. They also noted the similarity of the genus Antrobia to, but distinguished it from, the genus Fontigens
Fontigens
Fontigens is a genus of minute freshwater snails with an operculum, aquatic gastropod molluscs or micromolluscs in the family Hydrobiidae.-Species:Species within the genus Fontigens include:* Tapered cavesnail, Fontigens holsingeri...
, which contains cave-adapted snails found in other caves and springs of the Ozark Plateau in Missouri and Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
.
According to the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...
this genus is in the subfamily Littoridininae within the family Cochliopidae
Cochliopidae
Cochliopidae is a family of small freshwater snails with gills and an operculum, aquatic gastropod mollusks.This family is in the superfamily Rissooidea and in the clade Littorinimorpha ....
.
Description
The Tumbling Creek cavesnail is a small, white, blind, aquatic snail.The shell
Gastropod 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 small, conical, well-rounded and pale-yellow with about 3.5 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...
. The dimensions of the type specimen are as follows: height 2.3 millimeters (mm) (0.09 inches (in)); diameter 2.0 mm (0.08 in); 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 1.2 mm (0.05 in); aperture diameter 1.1 mm (0.04 in).
Distribution
Its distribution is restricted to a single cave stream in Tumbling Creek Cave, in Taney County
Taney County, Missouri
Taney County is a county located in Southwest Missouri in the United States. As of the 2000 U.S. Census, the county's population was 39,703. In the 2010 census the counties population was 51,675 Its county seat is Forsyth....
, in southwestern Missouri
Missouri
Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...
.
Habitat
This snail is an animal which lives in caveCave
A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...
s, thus it is a troglobite
Troglobite
Troglobites are small cave-dwelling animals that have adapted to their dark surroundings. Troglobite species include spiders, insects, fish and others. They live permanently underground and cannot survive outside the cave environment. Troglobite adaptations and characteristics include a heightened...
. In addition it is an aquatic troglobite, and animals who live in this specialized kind of habitat are known as stygobites or stygofauna
Stygofauna
Stygofauna are any fauna that live within groundwater systems, such as caves and aquifers, or more specifically small, aquatic groundwater invertebrates, though terrestrial air-breathing subterranean animals are also sometimes included...
.
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 cavesnail, 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 cavesnail). Because Tumbling Creek cavesnails are usually concentrated in those sections of Tumbling Creek Cave which are adjacent to large deposits of bat guanoGuano
Guano is the excrement of seabirds, cave dwelling bats, and seals. Guano manure is an effective fertilizer due to its high levels of phosphorus and nitrogen and also its lack of odor. It was an important source of nitrates for gunpowder...
, 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 cavesnails has significantly decreased over the past few decades, from an estimated 15,118 in 1973, 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 speciesUnited 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 August 14, 2002.
Although the primary limiting factor of the population appears to be decreased water quality
Water quality
Water quality is the physical, chemical and biological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose. It is most frequently used by reference to a set of standards against which...
, due to increased erosion
Erosion
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...
and water pollution
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
in the cave’s recharge area, scientific research is needed to confirm this hypothesis.
See also
- Antrobia breweri is a synonym (orth. error at 2010 IUCN Red List) of Antrorbis breweri cf.
External links
- Wooley C. M. (September 22, 2003). "Approved Recovery Plan for the Tumbling Creek Cavesnail (Antrobia culveri)". Federal RegisterFederal RegisterThe Federal Register , abbreviated FR, or sometimes Fed. Reg.) is the official journal of the federal government of the United States that contains most routine publications and public notices of government agencies...
68(183): 55060-55061. (Federal Register Notice of Availability recovery plan.) PDF. - (Page revised December 19, 2007). Endangered Species - Tumbling Creek Cavesnail (Antrobia culveri) Fact Sheet, 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.