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	Conservation Status (definitions)
IUCN (Red List) Status	Least Concern (LC) See threat category on the IUCN web site.
NatureServe Status	Use NatureServe Explorer to see status.
CITES	No CITES Listing
Other International Status	None
National Status	None
Regional Status	None

Description
A cave-dwelling salamander. This is the only known blind, troglobitic salamander which undergoes a complete metamorphosis. Adults are white, pinkish white, or light brown on the dorsum and venter. The reduced eyes are dark spots visible through the partially fused eyelids. Adults are 36-70 mm snouth to vent length (75-135 mm total length) with 16-19 costal grooves. Sexually mature males have a slightly swollen upper lip and a pair of cirri, papilla-like extensions from the upper lip. Like many other plethodontid salmanders, males also have a mental gland, a raised area on the chin used in courtship. Hatchlings are 13 mm snout to vent length (17 mm total length). The larvae have bushy gills and a moderately high dorsal tail fin. The larvae are lightly pigmented (tan dorsally, often weakly stippled or mottled) and have functional eyes. The eyes become atrophied and the eyelids fuse at metamorphosis (Brandon 1970; 1971; Petranka 1998).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: Kansas, Missouri

View distribution map using BerkeleyMapper.

Restricted to two plateaus in the Ozark region of southern Missouri, extreme southeasten Kansas, and adjacent areas in Arkansas and Oklahoma. Adults are not known outside of caves, but larvae are found in caves and springs as well as nearby creeks. Adults may be found in water or on moist vertical rock walls which extend out of the water. Sandy or gravelly substrates are preferred by the larvae (Hendricks and Kezer 1958; Brandon 1970; 1971; Petranka 1998).

Life History, Abundance, Activity, and Special Behaviors
Courtship has not been described. Mating occurs from late spring through summer. Oviposition likely occurs from late summer to fall when females disapper from the surface. Oviposition sites have not been documented, but presumably are in rocky crevices. Female attendance of eggs is likely. Clutch size from one female was 13 (Brandon 1971; Petranka 1998).

Grotto salamanders are most active during spring and summer months when moisture levels in caves are high, food is abundant, and courtship is taking place. Adults feed on aquatic and terrestrial invertebrates, including flies, mosquito larvae and beetles. Isopods, fly larvae, and snails are preferred by larvae. Adults may function as a top predator in some cave systems. Predators have not been reported although larvae are likely to be vulnerable to crayfish (Brandon 1971; Petranka 1998).

Trends and Threats
Caves represent a fragile ecosystem vulnerable to disturbance and pollution. Long-term monitoring will be needed to determine population trends of these animals (Petranka 1998).

Comments
This species is unique in that it starts life as a larva, which metamorphoses underground into a terrestrial adult that loses its pigment and becomes blind, with the eyelids eventually fusing. Recent molecular studies have shown that it is a close relative of species of the genus Eurycea that occur nearby. It differs strikingly from these species in its larger size and cave-related features, but because it is phylogenetically nested within the Euryea multiplicata complex, Bonett and Chippindale placed it in Eurycea. In an alternative to Linnean classification, the name Typhlotriton could be retained as a clade name, for example in Phylocode. Because mitochondrial DNA sequence divergence within E. spelaea is relatively great, some of the populations might be recognized as distinct species (two additional species were described in the past but now included within E. spelaea).

References
 

Bonett, R., and Chippindale, P. T. (2004). ''Speciation, phylogeography, and evolution of life history and morphology in plethodontid salamanders of the Eurycea multiplicata complex.'' Molecular Ecology, 13(5).  

Brandon, R. A. (1970). ''Typhlotriton and T. spelaeus.'' Catalogue of American Amphibians and Reptiles. American Society of Ichthyologists and Herpetologists, 84.1-84.2.  

Brandon, R. A. (1971). ''Correlation of seasonal abundance with feeding and reproductive activity in the Grotto Salamander (Typhlotriton spelaeus).'' American Midland Naturalist, 86(1), 93-100.  

Hendricks, L. J., and Kezer, J. (1958). ''An unusual population of a blind cave salamander and its fluctuation during one year.'' Herpetologica, 14(1), 41-43.  

Petranka, J. W. (1998). Salamanders of the United States and Canada. Smithsonian Institution Press, Washington and London.

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