Typhlichthys subterraneus
Encyclopedia
Typhlichthys subterraneus is a species of fish
in the Amblyopsidae family. It is endemic to karst regions of the eastern United States
.
species. The Southern cavefish was described by Charles Frédéric Girard
in 1859 from a well near Bowling Green
, Warren County
, Kentucky
. Later, Eigenmann in 1905 described both T. osborni and T. wyandotte based on differences in head width and eye diameter. Typhlichthys osborni was described from Horse Cave, Kentucky
, whereas T. wyandotte was described from a well near Corydon, Indiana
, that was later destroyed. Recently, a well-like entrance into a cave on the property of a car dealership in Corydon was discovered and is believed to represent the type locality. Regardless, this species is generally considered invalid and was not listed as a locality by Woods and Inger (1957). Recent surveys in the vicinity of Corydon have failed to document T. subterraneus, finding only Amblyopsis spelaea. Typhlichthys eigenmanni (nomen nudum
) was described as a fourth species in the genus from Camden County, Missouri
. Recently, Parenti proposed that T. eigenmanni Charlton, 1933 is a subjective synonym of T. subterraneus. Woods and Inger (1957) synonymized all species under T. subterraneus on the basis of lack of any clear geographic pattern in morphological variation. A population from Sloans Valley Cave, Pulaski County, Kentucky
, differs in several ways from populations to the southwest in Tennessee along the Cumberland Plateau
and might represent an undescribed species.
and isopods
. However, their metabolic rates are depressed in order to survive food shortages. The reproductive capabilities of this species is considerably low, with fewer than 50 eggs per female. This provides restrictions on its capabilities for recovering from an even minor population decline. When young are produced, they brood in the female's gill chamber. Sexual maturity requires approximately two years, and the life span is approximately four years.
Typhlichthys subterraneus is listed as a vulnerable species
on the IUCN Red List
. Due to environmental threats, there has been a recent decline in geographical span and population density
. This is perhaps due to pollution
, lowering of the water table
, flooding of reservoirs, or cave vandalism. Throughout the range of occupation, the cavefish has been placed under various conservation categories. To reduce these detrimental effects, there are several things that can improve the Southern cavefish's status.
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
in the Amblyopsidae family. It is endemic to karst regions of the eastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Taxonomy
Typhlicthys subterraneus is a member of the family Amblyopsidae, and is one of four troglobiticTroglobite
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...
species. The Southern cavefish was described by Charles Frédéric Girard
Charles Frédéric Girard
Charles Frédéric Girard was a French biologist specializing in ichthyology and herpetology.Born in Mulhouse, France, he studied at the College of Neuchâtel, Switzerland as a student of Louis Agassiz. In 1847, he accompanied Agassiz as his assistant to Harvard...
in 1859 from a well near Bowling Green
Bowling Green, Kentucky
Bowling Green is the third-most populous city in the state of Kentucky after Louisville and Lexington, with a population of 58,067 as of the 2010 Census. It is the county seat of Warren County and the principal city of the Bowling Green, Kentucky Metropolitan Statistical Area with an estimated 2009...
, Warren County
Warren County, Kentucky
Warren County is a county located in the U.S. state of Kentucky, specifically the Pennyroyal Plateau and Western Coal Fields regions. It is included in the Bowling Green, Kentucky, Metropolitan Statistical Area. The population was 113,792 in the 2010 Census. The county seat is Bowling Green...
, Kentucky
Kentucky
The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
. Later, Eigenmann in 1905 described both T. osborni and T. wyandotte based on differences in head width and eye diameter. Typhlichthys osborni was described from Horse Cave, Kentucky
Horse Cave, Kentucky
Horse Cave is a city in Hart County, Kentucky, United States. The population was 2,252 at the 2000 census.- History :The city is best known for the large natural cave opening located on the south side of Main Street, from which the town's name is derived. As for the historical reason for the odd...
, whereas T. wyandotte was described from a well near Corydon, Indiana
Corydon, Indiana
Corydon is a town in Harrison Township, Harrison County, Indiana, United States, founded in 1808, and is known as Indiana's First State Capital. After Vincennes, Corydon was the second capital of the Indiana Territory from May 1, 1813, until December 11, 1816. After statehood, the town was the...
, that was later destroyed. Recently, a well-like entrance into a cave on the property of a car dealership in Corydon was discovered and is believed to represent the type locality. Regardless, this species is generally considered invalid and was not listed as a locality by Woods and Inger (1957). Recent surveys in the vicinity of Corydon have failed to document T. subterraneus, finding only Amblyopsis spelaea. Typhlichthys eigenmanni (nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
) was described as a fourth species in the genus from Camden County, Missouri
Camden County, Missouri
Camden County is a county located in the U.S. state of Missouri. As of 2000, the population was 37,051. Its county seat is Camdenton. The county was organized in 1841 as Kinderhook County and renamed in 1843, for Charles Pratt, 1st Earl Camden, Chancellor of England, and leader of the Whig...
. Recently, Parenti proposed that T. eigenmanni Charlton, 1933 is a subjective synonym of T. subterraneus. Woods and Inger (1957) synonymized all species under T. subterraneus on the basis of lack of any clear geographic pattern in morphological variation. A population from Sloans Valley Cave, Pulaski County, Kentucky
Pulaski County, Kentucky
Pulaski County is a county located in the U.S. state of Kentucky. The population was 63,063 in the 2010 Census. Its county seat is Somerset6. The county is named for Count Kazimierz Pułaski. Most of the county is a prohibition or dry county...
, differs in several ways from populations to the southwest in Tennessee along the Cumberland Plateau
Cumberland Plateau
The Cumberland Plateau is the southern part of the Appalachian Plateau. It includes much of eastern Kentucky and western West Virginia, part of Tennessee, and a small portion of northern Alabama and northwest Georgia . The terms "Allegheny Plateau" and the "Cumberland Plateau" both refer to the...
and might represent an undescribed species.
Distribution
This species is more commonly known as the Southern cavefish. This name is due to the southern states in which it is found, including Indiana, Alabama, Kentucky, Georgia, Missouri, Tennessee, Arkansas, and Oklahoma. The subterranean waters where the cavefish is found is divided by the Mississippi River. The regions that it occupies include the Ozark plateau of central and southeastern Missouri and northeastern Arkansas, the Cumberland and Interior low plateaus of northwest Alabama, northwest Georgia, central Tennessee and Kentucky, and southern Indiana. It has been observed that the species lives in solitary habitats and is mostly isolated.Ecology and conservation
Tyhplicthys subterraneus is mostly lentic, but can also be found in pools of streams near water tables. The cavefish feeds mostly on aquatic arthropods, such as amphipodsAmphipoda
Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. The name amphipoda means "different-footed", and refers to the different forms of appendages, unlike isopods, where all the legs are alike. Of the 7,000 species, 5,500 are classified...
and isopods
Isopoda
Isopods are an order of peracarid crustaceans, including familiar animals such as woodlice and pill bugs. The name Isopoda derives from the Greek roots and...
. However, their metabolic rates are depressed in order to survive food shortages. The reproductive capabilities of this species is considerably low, with fewer than 50 eggs per female. This provides restrictions on its capabilities for recovering from an even minor population decline. When young are produced, they brood in the female's gill chamber. Sexual maturity requires approximately two years, and the life span is approximately four years.
Typhlichthys subterraneus is listed as a vulnerable species
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. Due to environmental threats, there has been a recent decline in geographical span and population density
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...
. This is perhaps due to pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
, lowering of the water table
Water table
The water table is the level at which the submarine pressure is far from atmospheric pressure. It may be conveniently visualized as the 'surface' of the subsurface materials that are saturated with groundwater in a given vicinity. However, saturated conditions may extend above the water table as...
, flooding of reservoirs, or cave vandalism. Throughout the range of occupation, the cavefish has been placed under various conservation categories. To reduce these detrimental effects, there are several things that can improve the Southern cavefish's status.