FWS Focus

Overview

Characteristics
Overview

The Barton Springs salamander is a fully-aquatic, neotenic salamander that is entirely dependent on the Barton Springs Segment of the Edwards Aquifer and its spring openings and surrounding habitats to meet its feeding, breeding and sheltering requirements. This species was federally listed as endangered on April 30, 1997. The primary threats or reasons for listing the Barton Springs salamander were the degradation of quality and quantity of water makes up its aquatic habitat as a result of urban expansion over the watershed. The restricted range of this species makes it vulnerable to both acute and chronic groundwater contamination. It is also vulnerable to potentially catastrophic hazardous materials spills, increased water withdrawals from the Edwards Aquifer and various impacts to its surface habitat.

Scientific Name

Eurycea sosorum
Common Name
Barton Springs Salamander
FWS Category
Amphibians
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

The Barton Springs salamander inhabits water of high quality maintained by groundwater sourced from the Barton Springs Segment of the Edwards Aquifer. The Edwards Aquifer is characterized by open chambers such as caves, fractures and other cavities that were formed either directly or indirectly by the dissolution of subsurface rock formations. Surface water filters through the soil and recharge features like caves, faults, fractures, sinkholes or other open cavities, into the Edwards Aquifer and then it discharges from springs as groundwater. The Barton Springs salamander is typically found in surface habitats, like the wetted top layer of substrate in or near spring openings, pools and spring runs. In at least two of its known locations, this species has been found in subsurface habitats, which include caves or other underground areas of the underlying water source. Barton Springs salamanders move any unknown depth into interstitial spaces, meaning empty voids between rocks, within the spring or streambed substrate that provide foraging habitat and protection from predators and drought conditions.

Cave or Karst

A natural chamber or series of chambers in the earth or in the side of a hill or cliff. An irregular limestone region with sinkholes, underground streams and caverns.

River or Stream

A natural body of running water.

Characteristic category

Food

Characteristics
Food

Barton Springs salamanders appear to be opportunistic predators of small, live invertebrates. Amphipod remains have been found in the stomachs of wild-caught salamanders. Analysis involving stable isotope techniques indicated a high a preference for planarian flatworms (Dugesia sp.). Barton Springs salamanders have been found to increase their consumption of midge fly larvae (family Chironomidae) and amphipods (Hyalella azteca) only after the near depletion of the planarian population. This type of prey switching indicates an opportunist forging strategy whereby a predator changes its diet to take advantage of temporarily available prey.

Characteristic category

Behavior

Characteristics
Behavior

The Barton Springs salamander likely spends much of its time within the interstitial spaces of the freshwater substrates it inhabits. Studies have shown that they forage on invertebrate species opportunistically and demonstrate an innate predator recognition which allows them to differentiate between low and high-risk predator species within their habitats.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The Barton Springs salamander was first collected from Barton Springs in 1946 and formally described in 1993. Adults reach about 2.5 to 3 inches (63 to 76 mm) in total length. Adult body morphology includes reduced eyes and elongate, spindly limbs that are indicative of a semi-subterranean lifestyle. The head is relatively broad and deep in lateral view, and the snout appears somewhat truncate when viewed from above. On either side of the base of the head is a set of three feathery gills that are bright red. The tail is relatively short with a well-developed dorsal, or upper fin, and poorly developed ventral, or lower, fin.

Color & Pattern

The coloration on the salamander’s upper body varies from light to dark brown, purple, reddish brown, yellowish cream, or orange. The characteristic mottled salt-and-pepper color pattern on the upper body surface is due to brown or black melanophores, meaning cells that contain pigments called melanin, and silvery-white iridiophores, meaning cells that contain pigments called guanine, in the skin. The arrangement of these pigment cells is highly variable and can be widely dispersed in some Barton Springs salamanders and can cause them to have an overall pale appearance. In other salamanders the melanophores may be so dense that individuals have a dark brown appearance. The ventral, or underside, of the body is cream-colored and is often translucent so that some internal organs and developing eggs in females are readily visible. The upper and lower mid-lines of the tail usually exhibit some degree of orange-yellow pigmentation.

Characteristic category

Life Cycle

Characteristics
Reproduction

Gravid females, eggs and larvae are typically found throughout the year in the Barton Springs, which suggests that the salamander can reproduce year-round. Observations of courtship among captive pairs of Barton Springs salamanders are consistent with the tail-straddling walk which is a behavior unique to plethodontid salamanders. During courtship, the male deposits a spermatophore, or sperm packet attached to a glycoprotein base, which then becomes attached to a plant, rock or other substrate. The spermatophore is picked up by the female and stored in a specialized portion of the cloaca, known as the spermatheca. Females of some salamander species may store spermatophores for up to two and a half years before ovulation and fertilization occur. Females of some species may also store more than one spermatophore from one or different males. In most salamanders, fertilization is internal and occurs during egg-laying whereby sperm are released onto eggs as they pass through the female’s cloaca.

Life Span

The longevity of the Barton Springs salamander in the wild is unknown.

Life Cycle

Barton Springs salamanders are aquatic and neotenic, meaning they retain larval, gill-breathing morphology throughout their lives. These neotenic salamanders do not metamorphose and leave water. Instead, they live in water throughout their life cycle where they become sexually mature and eventually reproduce. Although only a few eggs have ever been found in the wild, captive Barton Springs salamanders deposit eggs onto various substrates in their environment.  Hatching occurs between 15 and 40 days after eggs have been deposited. Newly hatched larvae have a yolk sac to sustain their nutritional needs in the early days after hatching, but they begin feeding on prey items as soon as 10 or 11 days after hatching.

Characteristic category

Similar Species

Characteristics
Similar Species

The Barton Springs salamander is sympatric with, meaning that it occurs in the same range as, the Austin blind salamander (Eurycea waterlooensis). Morphological characteristics that distinguish the Austin blind salamander from the Barton Springs salamander include eyespots covered by skin instead of image-forming lenses, an extended snout, fewer costal grooves and pale to dark lavender coloration.

Geography

Characteristics
Range

Once only known from the four spring sites that make up the Barton Springs complex within Zilker Park in Austin, Texas, Barton Springs salamanders have now been determined to occur in 12 additional spring and cave sites in Hays and Travis Counties, Texas.

Launch Interactive Map

Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

14 Items

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Five Year Review

Recovery Plan

Recovery Plan

Five Year Review

1800
1810
1820
1830
1840
1850
1860
1870
1880
1890
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
2010
2020
2030
2040
2050
2060
2070
2080
2090
2100
2110
2120
2130
2140
2150
2160
2170
2180
2190
1964
1965
1966
1967
1968
1969
1971
1972
1973
1974
1975
1976
1977
1978
1979
1981
1982
1983
1984
1985
1986
1987
1988
1989
1991
1992
1993
1994
1995
1996
1997
1998
1999
2001
2002
2003
2004
2005
2006
2007
2008
2009
2011
2012
2013
2014
2015
2016
2017
2018
2019
2021
2022
2023
2024
2025
2026
2027
2028
2029
2031
2032
2033
2034
2035
2036
2037

Listing

Dec 30, 1982

Dec 30, 1982 Listing
Review of Vertebrate Wildlife for Listing as End. or Thr. Species
  • Publication type: CNOR
Item 1

Listing

Sep 18, 1985

Sep 18, 1985 Listing
Review of Vertebrate Wildlife; Notice of Review; 50 FR 37958-37967
  • Publication type: CNOR
Item 2

Listing

Jan 6, 1989

Jan 6, 1989 Listing
ETWP; Animal Notice of Review; 54 FR 554 579
  • Publication type: CNOR
Item 3

Listing

Nov 21, 1991

Nov 21, 1991 Listing
ETWP; Animal Candidate Review for Listing as Endangered or Threatened Species; 56 FR 58804 58836
  • Publication type: CNOR
Item 4

Listing

Dec 11, 1992

Dec 11, 1992 Listing (Substantial)
ETWP; Notice of Finding on Petition to List Barton Springs Salamander; 57 FR 58779 58781
  • Publication type: 90 day petition finding
Item 5

Listing

Feb 17, 1994

Feb 17, 1994 Listing (Endangered)
ETWP; Proposal to List the Barton Springs Salamander as Endangered
  • Publication type: Proposed
Item 6

Listing

Nov 15, 1994

Nov 15, 1994 Listing
ETWP; Animal Candidate Review for Listing as Endangered or Threatened Species.
  • Publication type: CNOR
Item 7

Listing

Feb 28, 1996

Feb 28, 1996 Listing
ETWP; Review of Plant and Animal Taxa That Are Candidates for Listing as Endangered or Threatened S…
  • Publication type: CNOR
Item 8

Listing

Sep 4, 1996

Sep 4, 1996 Listing
ETWP; Withdrawal of Proposed Rule To List the Barton Springs Salamander as Endangered
  • Publication type: Withdrawal
Item 9

Listing

Apr 30, 1997

Apr 30, 1997 Listing (Endangered)
ETWP; Final Rule To List the Barton Springs Salamander as Endangered
  • Publication type: Final
Item 10

Five Year Review

Jan 25, 2005

Jan 25, 2005 Five Year Review (Information Solicitation)
Notice of Availability of the Draft Barton Springs Salamander Recovery Plan; Notice of Initiation of…
  • Publication type: Notice
Item 11

Recovery Plan

Jan 25, 2005

Jan 25, 2005 Recovery Plan (Document Availability (non-FR))
Notice of Availability of the Draft Barton Springs Salamander Recovery Plan; Notice of Initiation of…
  • Publication type: Draft
Item 12

Recovery Plan

Sep 21, 2005

Sep 21, 2005 Recovery Plan (Document Availability (non-FR))
Notice of Availability of the Barton Springs Salamander Final Recovery Plan
  • Publication type: Final
Item 13

Five Year Review

Jul 26, 2019

Jul 26, 2019 Five Year Review (Information Solicitation)
5-Year Status Reviews of 36 Species in Arizona, New Mexico, Texas, Utah, and Mexico; Notice of initi…
  • Publication type: Notice
Item 14