The western grotto salamander (''Eurycea spelaea''), also called the Ozark blind salamander and previously known as just the grotto salamander, is a species of

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

in the family

Plethodontidae Plethodontidae, or lungless salamanders, are a family of salamanders. With over 500 species, lungless salamanders are by far the largest family of salamanders in terms of their diversity. Most species are native to the Western Hemisphere, from B ...

. It is

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 ...

to the United States. Its natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s are freshwater

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a he ...

s, inland

karst Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. Ther ...

s, and

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. It is not currently threatened, but vulnerable to changes in

groundwater Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit ...

quality and reduction in

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

population.

Taxonomy

The grotto salamander was discovered in 1891 on 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 ...

, and described by

Leonhard Hess Stejneger Leonhard Hess Stejneger (30 October 1851 – 28 February 1943) was a Norwegian-born American ornithologist, herpetologist and zoologist. Stejneger specialized in vertebrate natural history studies. He gained his greatest reputation with reptile ...

in 1892. It is now considered a member of the genus '' Eurycea'', but was originally described as ''Typhlotriton speleus''.Graening, G. Fenolio, D. Slay, M. (2011). Cave Life of Oklahoma and Arkansas. University of Oklahoma Press, Norman. p. 7 . Previously, it was thought to have occurred throughout the Ozark Plateau, but during the mid-20th century, two other species were described from populations formerly assigned to ''E. spelaea'': the

northern grotto salamander The northern grotto salamander (''Eurycea nerea'') is a species of salamander in the family Plethodontidae. It is endemic to the south-central United States. Taxonomy It is now considered a member of the genus '' Eurycea'', but was originally ...

(''E. nerea'') of the Salem Plateau and adjacent West Springfield Plateau, and the

southern grotto salamander The southern grotto salamander (''Eurycea braggi'') is a species of salamander in the family Plethodontidae. It is endemic to northern Arkansas in the United States. Taxonomy It is now considered a member of the genus '' Eurycea'', but was ori ...

(''E. braggi'') of the East Springfield Plateau. These species were later lumped in with ''E. spelaea''. However, a 2017 study found all three to be phylogenetically distinct from one another and have deep divergence times dating back to the Late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

; ''E. spelaea'' is thought to be the sister species to the clade comprising ''E. nerea'' and ''E. braggi''. All three grotto salamanders are thought to descend from an ancestral surface-dwelling form.

Distribution and habitat

This species inhabits the

regions beneath the West Springfield Plateau of the

Ozark Mountains 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 cover ...

of extreme northwestern

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 ...

, extreme southeastern

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

, 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 ...

, and northeastern

Oklahoma Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...

. As larvae the western grotto salamander lives in springs and streams near cave entrances. As adults, They migrate deep into the caves themselves and live out their lives underground. They prefer waters between 5.5 and 16.5 °C, and feed on small, cave-dwelling invertebrates such as ''

Gammarus ''Gammarus'' is an amphipod crustacean genus in the family Gammaridae. It contains more than 200 described species, making it one of the most species-rich genera of crustaceans. Different species have different optimal conditions, particularly ...

'', though they are also known to eat

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 ...

as well.Trauth, S. Robinson, H. Plummer, M. (2004) The Amphibians and Reptiles of Arkansas. University of Arkansas press. pp. 104–05 .

Description

The larvae of this salamander are bold in coloration: brownish or purplish gray, sometimes with yellow flecks on the sides. Adults can grow up to 13.5 cm and larvae tend to be between 10 and 30mm. They have a distinctive high tail fin and external

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 ...

Larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

that live in an environment with light, like outside the caves in brooks or streams, have fully functional

eyes An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

, even if their vision seems to fade in older individuals. If they grow up in darkness, it will result in closed lids or degenerate retinas. After two or three years, the larvae

metamorphose Metamorphosis is a biological process by which an animal physically developmental biology, develops including birth, birth transformation or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through ...

, at which point they lose their gills, their

eyelids An eyelid ( ) is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. "Palpebral" ...

gradually fuse shut over the following year and is eventually covered with supraocular skin, and the now blind adult form spends the rest of its life in a cave. Because the larval eyes continue to grow till metamorphosis occurs, adults will have larger eyes the later the metamorphosis starts, and vice versa. The species is one of very exceptions from the rule that cave salamanders are paedomorphic. It has been hypothesized that the larval form is most beneficial in caves because the majority of the prey lives in water, and their aquatic feeding mechanism is more efficient in the larval form than that of post-metamorphic individuals. The Western grotto salamander has been described as an opportunistic and omnivorous feeder, which in addition to eating small aquatic animals is also coprophagic, feeding on

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 l ...

, which is just as rich in nutrients as their living prey. This allows them to exploit the available food sources in both the aquatic and terrestrial environments inside the cave.Coprophagy in a cave-adapted salamander; the importance of bat guano examined through nutritional and stable isotope analyses
/ref> Alongside ''E. nerea'', ''E. braggi'', and the '' West Virginia spring salamander'', the western grotto salamander is the only cave salamander which undergoes metamorphosis. The adult form is pinkish white, sometimes with traces of orange on its tail, feet, and sides, and has 16–19 costal grooves.Conant, Roger, and Joseph T. Collins (1998) Peterson Field Guide to Reptiles and Amphibians Eastern/Central North America. 3rd ed. Houghton Mifflin Company, p. 498 Behler, John L., and F W. King (1979). National Audubon Society Filed Guide to North American Reptiles and Amphibians. New York: Alfred A. Knopf, Inc, p. 356

References

{{Authority control Plethodontidae Cave salamanders Ozarks Endemic amphibians of the United States Amphibians described in 1892 Taxa named by Leonhard Stejneger Taxonomy articles created by Polbot

Taxonomy

Distribution and habitat

Description

See also

References