Comprehensive Report Species

Concept Reference: Chippindale, P. T., A. H. Price, and D. M. Hillis. 1993. A new species of perennibranchiate salamander (Eurycea: Plethodontidae) from Austin, Texas. Herpetologica 49:248-59.
Concept Reference Code: A93CHI01NAUS
Name Used in Concept Reference: Eurycea sosorum
Taxonomic Comments: Sweet (1984) found this salamander to be structurally intermediate between E. neotenes and E. tridentifera. Chippindale et al. (1993, 2000) determined that this species is morphologically and biochemically distinct from all known species of plethodontids. Included in E. neotenes by Brown (1950, 1967).

NatureServe Status

Global Status: G1
Global Status Last Reviewed: 25Mar2002
Global Status Last Changed: 10Oct1996
Rounded Global Status: G1 - Critically Imperiled
Reasons: Occurs in spring outlets in only one location in Travis County, Texas; vulnerable to water contamination.
Nation: United States
National Status: N1 (05Nov1996)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.

United States

Texas (S1)

Other Statuses

U.S. Endangered Species Act (USESA): LE: Listed endangered (30Apr1997)
U.S. Fish & Wildlife Service Lead Region: R2 - Southwest
IUCN Red List Category: VU - Vulnerable

NatureServe Global Conservation Status Factors

Range Extent: <100-250 square km (less than about 40-100 square miles)
Range Extent Comments: Barton Springs, Edwards Aquifer, Austin, Travis County, Texas; occurs in three of four hydrologically connected spring outlets (see Chippindale et al. [1993] for further details). Barton Springs is fed by the Barton Springs segment of the Edwards Aquifer; this segment occurs in portions of Blanco, Hays, and Travis counties.

Number of Occurrences: 1 - 5
Number of Occurrences Comments: Only one occurrence.

Population Size Comments: Total population size is unknown. Observable population in Eliza Pool was dozens or hundreds in the 1970s, 15 in November 1992, 0 from December 1993 to May 1995, 0-28 between June 1995 and July 1996. Reportedly abundant in Barton Springs Pool in 1946, about 150 were seen in November 1992, and survey counts between April 1995 and April 1996 ranged from 3 to 45 individuals. No more than 20 have been observed during any one survey of the Sunken Garden Springs outlet, but this site is difficult to survey. See Federal Register, 4 September 1996.

Overall Threat Impact: Unknown
Overall Threat Impact Comments: Vulnerable to extinction due to very limited distribution within a sensitive habitat; primary threat is contamination of the waters that feed Barton Springs (see Federal Register, 17 February 1994, for detailed discussion). The Barton springs Aquifer has been designated by the Texas Water Commission as one of the aquifers most vulnerable to pollution in Texas (Chippindale et al. 1993). Excessive groundwater withdrawal is a potential threat. Under pool maintenance procedures in place as of 1992, human use of the Barton Springs Pool for swimming did not conflict with the continued existence of the salamander (Chippindale et al. 1993). Recreational swimming in the Barton Springs Pool does not pose a threat.

Short-term Trend Comments: Declined during the 1970s and 1980s; new maintenance procedures at Barton Springs resulted in habitat recovery (e.g., reestablishment of vascular plants) and salamander population increases in the early 1990s. See Federal Register, 17 February 1994, p. 7969; 30 April 1997, pp. 23377-23378) for information on population history at each occupied site at Barton Springs. Current trend is unknown.

Long-term Trend:
Long-term Trend Comments: Likely stable in extent of occurrence, uncertain long-term trend in population size, area of occurrence, and number/condition of occurrences.

Intrinsic Vulnerability: Highly to moderately vulnerable.

Environmental Specificity: Very narrow. Specialist or community with key requirements scarce.

Other NatureServe Conservation Status Information

Inventory Needs: Determine underground extent of habitat and population; determine limiting factors.

Protection Needs: Protect the single EO and its water supply (see "Barton Springs Salamander Conservation Agreement and Strategy").

Global Range: (<100-250 square km (less than about 40-100 square miles)) Barton Springs, Edwards Aquifer, Austin, Travis County, Texas; occurs in three of four hydrologically connected spring outlets (see Chippindale et al. [1993] for further details). Barton Springs is fed by the Barton Springs segment of the Edwards Aquifer; this segment occurs in portions of Blanco, Hays, and Travis counties.

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.

Endemism: endemic to a single state or province

U.S. & Canada State/Province Distribution
United States	TX

Range Map

Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: IUCN, Conservation International, NatureServe, and collaborators, 2004

U.S. Distribution by County
State	County Name (FIPS Code)
TX	Hays (48209), Travis (48453)

* Extirpated/possibly extirpated

U.S. Distribution by Watershed
Watershed Region	Watershed Name (Watershed Code)
12	Austin-Travis Lakes (12090205)+

+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated

Basic Description: A small, brown, gilled slamander.
General Description: A small, olive-brown salamander with a coarse-grained, blotchy "salt-and-pepper" pattern; retains external gills throughout life. Standard length (tip of snout to posterior margin of vent) averages about 29 mm, maximum about 37 mm; tail length averages 21 mm, maximum about 31 mm.
Diagnostic Characteristics: Dorsal coloration is distinctive in most specimens; the combination of pigment gaps (pale areas due to an absence of melanophores) and frequently high concentrations of silvery-white dorsal iridophores apparently is unique (Chippindale et al. 1993). Slight "shovel-nose" evident in most specimens is not as extreme as in E. TRIDENTIFERA, but this characteristic does distinguish most individuals from members of surface populations that currently are assigned to E. NEOTENES and E. NANA (Chippindale et al. 1993). Eyes are significantly reduced in comparison to individuals from other surface-dwelling populations of central Texas EURYCEA; also, limbs of SOSORUM generally are proportionately longer (Chippindale et al. 1993). EURYCEA SOSORUM typically has 16 presacral vertebrae, in contrast to the 17 typically present in surface-dwelling members of the E. NEOTENES species group. Differs from other populations of central Texas EURYCEA and TYPHLOMOLGE RATHBUNI also by a unique combination of alleles (see Chippindale et al. 1993).
Reproduction Comments: Recently hatched young have been found in November, March, and April, and females with well-developed eggs have been found from September through January; in captivity, one female retained well-developed eggs for over a year (Chippindale et al. 1993). Apparently breeds year-round.
Non-Migrant: Y
Locally Migrant: N
Long Distance Migrant: N
Riverine Habitat(s): SPRING/SPRING BROOK
Subterranean Habitat(s): Subaquatic
Special Habitat Factors: Benthic
Habitat Comments: Spring dweller; occurs in the fourth largest spring in Texas; inhabited spring outlets are impounded/retained by concrete structures. Evidently, this species occurs primarily in nonsubterranean waters; unlikely to range extensively underground but can live in subterranean waters (Chippindale et al. 1993). Usually found under rocks or in gravel in about 0.1-5 m of water; also takes refuge among aquatic vascular plants, vegetative debris, and algae when such habitat is available (Chippindale et al. 1993). Spring habitat flows throughout the year and maintains a fairly constant temperature of 20 C. See Federal Register (17 February 1994, p. 7969-7970) for hydrological information on the Barton Springs segment of the Edwards Aquifer. Oviposition likely occurs in subsurface habitat (Federal Register, 4 September 1996, p. 46609).
Adult Food Habits: Invertivore
Immature Food Habits: Invertivore
Food Comments: Diet apparently consists almost entirely of amphipods and other small invertebrates.
Length: 6 centimeters

Management Requirements: Successful spawning of captives has been accomplished at the Dallas Aquarium and at the National Biological Service's Midwest Science Center in Missouri, but hatching success has been very low.

Group Name: Aquatic/Wetland Plethodontid Salamanders

Use Class: Not applicable
Minimum Criteria for an Occurrence: Occurrences are based on evidence of historical presence, or current and likely recurring presence, at a given location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals (including larvae or eggs) in or near appropriate habitat where the species is presumed to be established and breeding.
Separation Barriers: Busy highway, especially with high traffic volume at night; other totally inappropriate habitat that the salamanders cannot traverse.
Alternate Separation Procedure: Separation distance for stream-dwelling species along riverine corridors: 10 stream km. Separation distance for other freshwater aquatic and wetland habitats: 3 km. Separation distance for upland habitat: 1 km.
Separation Justification: These salamanders rarely successfully cross roadways that have heavy traffic volume at night, when most movements occur. Salamanders in this Specs Group, except strictly subterranean species, tend to be able to traverse upland habitat when conditions are wet, and generally they can pass through atypical wetland and aquatic habitats to reach another patch of suitable habitat. However, Grover and Wilbur (2002) created replicated seeps at distances of 3, 15, and more than 30 m from streams or natural seeps and found that Desmognathus fuscus and Gyrinophilus porphyriticus colonized the new seeps at 3 m and 15 m but were rare or absent at new seeps more than 30 m from the nearest stream or natural seep.

Although these specifications do not include rivers as barriers, Adams and Beachy (2001) documented morphological variation among populations of Gyrinophilus porphyriticus in the southern Appalachian Mountains and found patterns "consistent with the hypothesis that large rivers restrict sizable gene flow." Large rivers probably function at least as unsuitable habitat for many species in this Specs Group.

Compared to larger ambystomatid salamanders, the movements of plethodontids are poorly documented, but home ranges likely tend to be very small, on the order of a few meters to a few dozen meters in length or diameter. Yet, on occasion, dispersing individuals likely travel at least several hundred meters, and stream-dwelling species likely disperse much farther along riverine corridors. Over a number of years, it is likely that these salamanders can spread multiple kilometers through suitable habitat.
Inferred Minimum Extent of Habitat Use (when actual extent is unknown): .1 km
Date: 28Oct2004
Author: Hammerson, G.

Justification: Use the Generic Guidelines for the Application of Occurrence Ranks (2008).
The Key for Ranking Species Occurrences Using the Generic Approach provides a step-wise process for implementing this method.
Key for Ranking Species Element Occurrences Using the Generic Approach (2008).

NatureServe Conservation Status Factors Edition Date: 04Apr2011
NatureServe Conservation Status Factors Author: Hammerson, G.
Element Ecology & Life History Edition Date: 02Nov1995
Element Ecology & Life History Author(s): Hammerson, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

Allen, C. R., S. Demarais, and R. S. Lutz. 1994. Red imported fire ant impact on wildlife: an overview. The Texas Journal of Science 46(1):51-59.

BARRETT, EVELYN P. AND CAROLINE P. BENJAMIN. 1977. AN ANALYSIS OF THE PIGMENTATION OF THE EPIGEAL EURYCEA OF THE TEXAS EDWARDS PLATEAU. COPEIA 1977(1):59-65.

Blackburn, L., P. Nanjappa, and M. J. Lannoo. 2001. An Atlas of the Distribution of U.S. Amphibians. Copyright, Ball State University, Muncie, Indiana, USA.

Chippindale, P. T., A. H. Price, J. J. Wiens, and D. M. Hillis. 2000. Phylogenetic relationships and systematic revision of central Texas hemidactyliine plethodontid salamanders. Herpetological Monographs 14:1-80.

Chippindale, P. T., A. H. Price, and D. M. Hillis. 1993. A new species of perennibranchiate salamander (Eurycea: Plethodontidae) from Austin, Texas. Herpetologica 49:248-59.

Chippindale, P. T., D. M. Hillis, and A. H. Price. 1994. Final Section 6 report. Project 3.4.� Grant No. E-1. Relationships, status, and distribution of central Texas hemidactyliine plethodontid salamanders (Eurycea and Typhlomolge).85 pp. 30 Nov 1999..

Chippindale, P. T., D. M. Hillis, and A. H. Price. 1994. Relationships, status, and distribution of central Texas hemidactyliine plethodontid salamanders (Eurycea and Typhlomolge). Final Section 6 Report, July 1994. 21 pp. + 1 fig.

Chippindale, P.T. 2000. Species boundaries and species diversity in the central Texas hemidactyliine plethodontid salamanders, genus Eurycea. The Biology of Plethodontid Salamanders. Bruce, R., Houck, L. and Jaeger, R.,editor. 149-160. Kluwer Academic/Plenum Publishing. New York.

Chippindale, P.T. and Price, A.H. In Press. Conservation of spring and cave salamanders (Eurycea). Declining Amphibians: A United States' Response to the Global Problem. Lannoo, M.J.,editor. 363-376. University of California Press. Berkeley, California.

Chippindale, Paul T., A.H. Price, and D.M. Hillis. 1993. A new species of perennibranchiate salamander (Eurycea: Plethodontidae) from Austin, Texas. Herpetologica. 49(2):248-259.

DIXON, JAMES R. 1987. AMPHIBIANS AND REPTILES OF TEXAS, WITH KEYS, TAXONOMIC SYNOPSES, BIBLIOGRAPHY, AND DISTRIBUTION MAPS. TEXAS A& M UNIV. PRESS, COLLEGE STATION. xii + 434 pp.

GARRETT, JUDITH M. AND DAVID G. BARKER. 1987. A FIELD GUIDE TO REPTILES AND AMPHIBIANS OF TEXAS. TEXAS MONTHLY PRESS, AUSTIN. xi + 225 pp.

GEHLBACH, FREDERICK R. 1991. THE EAST-WEST TRANSITION ZONE OF TERRESTRIAL VERTEBRATES IN CENTRAL TEXAS: A BIOGEOGRAPHICAL ANALYSIS. TEXAS J. SCI. 43(4):415-427.

Gillespie, J.H. 2011. Ecology and conservation of the endangered Barton Springs salamander (Eurycea sosorum). PhD dissertation, University of Texas at Austin. 143 pp.

Hansen R., Chamberlain, D. and Lechner, M. 1998. Final environmental assessment/habitat conservation plan for issuance of a section 10(a)(1)(B) permit for incidental take of the Barton Springs salamander (Eurycea sosorum) for the operation and maintenance of Barton Springs Pool and adjacent springs. City of Austin and U.S. Fish and Wildlife Service. Austin, Texas.

Hillis, D. M., D. A. Chamberlain, T. P. Wilcox, and P. T. Chippindale. 2001. A new species of subterranean blind salamander (Plethodontidae: Hemidactyliini: Eurycea: Typhlomolge) from Austin, Texas, and a systematic revision of central Texas paedomorphic salamanders. Herpetologica 57:266-280.

Sweet, S. S. 1984. Secondary contact and hybridization in the Texas cave salamanders EURYCEA NEOTENES and E. TRIDENTIFERA. Copeia 1984:428-441.

Woods, H.A., M.F. Poteet, P.D. Hitchings, R.A. Brain, and B.W. Brooks. 2010. Conservation physiology of the Plethodontid salamanders Eurycea nana and E. sosorum: response to declining dissolved oxygen. Copeia 2010(4):540-553.

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Kingdom	Phylum	Class	Order	Family	Genus
Animalia	Craniata	Amphibia	Caudata	Plethodontidae	Eurycea


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