Wednesday, February 08, 2017Register
 Federally Threatened and Endangered Amphibians of the Edwards Aquifer

Barton Springs Salamander
Eurycea sosorum

Thumbnail image of Barton Springs Salamander, courtesy of Texas Parks and Wildlife Department

[Photo: Texas Parks and Wildlife]

Description: The Barton Springs salamander is a fully aquatic salamander of the genus Eurycea, in the family Plethontidae (lungless salamanders). It is believed that the Barton Springs salamander was formerly a surface species, but due to extremely reduced surface habitat, has adapted to subsurface environments. Because of this shift in habitat, the Barton Springs salamander displays some cave-adapted morphologies. This species is most closely related (genetically) to the Comal blind salamander and the Cascade Caverns salamander, although it is not found in the same range. It can be distinguished by its less pronounced shovel nose and the blotchy appearance of its dorsal surface. This species exhibits a range of colors from gray, brown, or yellowish-brown to purplish-gray, with a "salt-and-pepper" type mottling on its dorsal surface and a creamy, transparent color on its ventral surface. The Barton Springs Salamander is 2.5 inches (6.4 cm) long with elongated, slender limbs and reduced eyes. These salamanders have three pairs of prominent red external gills. It has a sizable dorsal fin, but an underdeveloped ventral fin.

Life History: The Barton Springs salamander is an opportunistic predator and feeds on amphipods, snails, mayfly larvae, adult riffle beetles, and other types of small aquatic invertebrates. It is known to breed year round and females reach maturity at 11-17 months. The Barton Springs salamander has a lifespan of at least 10 years. This salamander respires by utilizing oxygen exchange via its external gills and skin, which requires flowing water. Salamander eggs also require a high degree of oxygenation for development of the embryo.

Habitat: This species is found in Barton Springs at depths of 1.5-15 feet (0.5-5 m). It lives under rocks and gravel amongst aquatic plants, algae, and organic debris such as leaves. It is rarely found in silted areas or on exposed limestone. This species usually inhabits the spring openings where it can take advantage of both surface and subsurface habitats. These openings provide an abundant source of food, constant water temperature (68-72 degrees F [20-22 deg C]), neutral pH, and clean, clear, flowing water.

Distribution: Eurycea sosorum is found in four spring outlets at Barton Springs in Zilker Park in Austin, TX (Travis County). These four spring outlets are 1) Main Springs or Parthenia Springs 2) Eliza Springs 3) Sunken Garden Springs and 4) Upper Barton Springs. Critical habitat has not been designated for this species. The map below depicts the areas where this species has been reported (according to literature review).

Reported Species Distribution of the Barton Springs Salamander (Eurycea sosorum) [Figure: Houston Advanced Research Center]

Reported Species Distribution of the Barton Springs Salamander (Eurycea sosorum) [Figure: Houston Advanced Research Center]. Click on map for larger image.

 

Status: The Barton Springs salamander is a state and federally listed (1997) endangered species. This species requires clean and flowing water with high dissolved oxygen for respiration and embryo development. Additionally, this species is sensitive to changes in salinity, supersaturation of water, and excessive sedimentation. Thus, surface water quality and quantity, and groundwater quality and quantity, are important for its survival. Due to its extremely restricted range, this population is sensitive to a major toxic pollution event.

Resources:

Chippindale, Paul T., Price, Andrew, H., Hillis, David M. 1993. A New Species of Perennibranchiate Salamander (Eurycea: Plethodontidae) from Austin, Texas. Herpetologica, Vol. 49, No. 2 (Jun., 1993), pp. 248-259.

Texas Parks and Wildlife, Barton Springs Salamander Species Profile

US Fish and Wildlife Service, Endangered Species Listing

US Fish and Wildlife Service, Barton Springs Salamander Recovery Plan

 

Blanco Blind Salamander
Eurycea robusta (formerly Typhlomolge robusta)

Thumbnail image of Blanco Blind Salamander, courtesy of University of Texas

[Photo: Jessie Maisano, University of Texas at Austin]

Description: The Blanco blind salamander is a fully aquatic, subterranean species of the Eurycea genus, in the family Plethodontidae (lungless salamanders). Only one specimen of this species has been collected (1951). It is 2.2 inches (5.7 cm) long with a large head and flattened snout. This species has bright red external gills, a finned tail, and long slender legs. It has 12 costal grooves and 4 fingers on its front feet and five fingers on its hind feet. The Blanco blind salamander is very morphologically similar to the Texas blind salamander and is distinguished based upon its range, molecular differences, and a slightly more robust body with stouter legs. The Blanco blind salamander exhibits extreme cave-adapted morphologies which includes vestigial eyes and translucent skin, giving the salamander a white or pale pink appearance.

Life History: There is very little known of its feeding habits or life cycle; however, due to its close relationship to the Texas Blind Salamander, it may have similar characteristics.

Habitat: This species lives in subterranean streams deep within the Edwards Aquifer. There is very little known about this species because of difficulty in locating it.

Distribution: Eurycea robusta lives in subterranean streams of the Edwards Aquifer, North and East of the Blanco River in Hays County, in Central Texas. This species is believed to be more widely spread deep within the karst aquifer in this area; hoever, because only one specimen ha been collected (1951), it is difficult to define the range of this species. The map below depicts the area were this species has been reported (according to literature review).

Reported Species Distribution of the Blanco Blind Salamander (Eurycea robusta) [Figure: Houston Advanced Research Center]

Reported Species Distribution of the Blanco Blind Salamander (Eurycea robusta) [Figure: Houston Advanced Research Center]. Click on map for larger image. 

 

Status: The Blanco blind salamander is a state listed threatened species. This species was recommended for federal listing, but rejected due to lack of information about the species. Only one specimen has been collected (1951).

Resources:

Chippindale, Paul T., Price, Andrew H., Wiens, John J. and Hillis, David M. 2000. Phylogenetic Relationships and Systematic Revision of Central Texas Hemidactyliine Plethodontid Salamanders. Herpetological Monographs, Vol. 14, pp. 1-80.

University of Texas, Herps of Texas, Blanco Blind Salamander

Cascade Caverns Salamander
Eurycea latitans

Thumbnail image of Cascade Caverns Salamander, courtesy of Dante B Fenolio, copyright 2007

[Photo: Dante B Fenolio, © 2007]

Description: The Cascade Caverns salamander is a fully aquatic, subterranean species of the Eurycea genus, in the family Plethontidae (lungless salamanders). Its size ranges from 2.5-4.1 inches (6.4-10.5 cm) long. It is pale in color, exhibiting a tannish-brown netted pattern with white speckling on its dorsal surface. This salamander has a flat snout and sloping forehead. It has vestigial eyes and bright red external gills which are retained throughout life. Its body and limbs are stouter than other closely related salamanders, and it has 14-15 costal grooves.

Life History: Due to difficulty in finding these salamanders, little is known of their life history; although it is assumed to be similar to the closely related species, Texas salamander and Comal blind salamander.

Habitat: The Cascade Caverns salamander lives in freshwater pools and streams in underground limestone caves of the Edwards Aquifer.

Distribution: Eurycea latitans is found in several caves in Comal, Hays, Kendall, and Kerr counties, Edwards Aquifer, central Texas. The caves where this salamander has been found are Cascade Caverns, Bear Creek Spring, Cibolo Creek Spring, Kneedeep Cave Spring, Less Ranch Spring, Pfeiffer's Water Cave, Cherry Creek Spring, and Cloud Hollow Springs. The map below depicts the area where this species has been reported (according to literature review).

Reported Species Distribution of the Cascade Caverns Salamander (Eurycea latitans) [Figure: Houston Advanced Research Center]

Reported Species Distribution of the Cascade Caverns Salamander (Eurycea latitans) [Figure: Houston Advanced Research Center]. Click on map for larger image. 

 

Status: The Cascade Caverns salamander is a state listed threatened species. Because this salamander respires via external gills and through its skin, it requires clean, clear flowing water, with a high dissolved oxygen content, for survival.

Resources:

Chippindale, Paul T., Price, Andrew H., Wiens, John J. and Hillis, David M. 2000. Phylogenetic Relationships and Systematic Revision of Central Texas Hemidactyliine Plethodontid Salamanders. Herpetological Monographs, Vol. 14, pp. 1-80.

University of Texas, Herps of Texas, Cascade Caverns Salamander

San Marcos Salamander
Eurycea nana

Thumbnail image of San Marcos Salamander, courtesy of Texas Parks and Wildlife Department

[Photo: Texas Parks and Wildlife]

Description: The San Marcos salamander is a small and slender-limbed member of the Eurycea genus of the Lungless salamander family (Plethontidae). It grows up to 2.5 inches (6.4 cm) long and has a thin tail with a dorsal fin and 16-17 costal grooves. This species is reddish-brown in color with small yellow flecks on its back and a yellowish-white underbelly. This species can change to different shades of brown on its dorsal surface depending on the color of its surrounding substrate. It has small eyes with dark rings around them and external gills that are bright red in color, which it retains throughout life.

Life History: The San Marcos salamander lives and hunts in moss and algae. The dark reddish-brown color of the algae it inhabits almost perfectly matches the dark color on the dorsal surface of the San Marcos salamander. Breeding occurs throughout the year (peaking in late spring) and females lay eggs both singly or in small groups. It eats amphipods, small aquatic insects, and snails.

Habitat: The San Marcos salamander prefers to live on unsilted sand, gravel, or rocks from 1-8 inches (2.5-20 cm) in diameter with surrounding aquatic vegetation such as moss and matted, murky, floating algal mats. This species requires thermally and chemically constant, flowing water (70-72 degrees F [21-22 deg C]) that is clean and clear.

Distribution: Eurycea nana can be found from Spring Lake at the headwaters of the San Marcos River down to 0.5 miles below the Interstate 35 bridge, Hays County, central Texas.

The map below depicts the critical habitat for this species, as designated by the US Fish and Wildlife Service pursuant to the Endangered Species Act.

NOTE: No warranty is given, expressed or implied, as to the accuracy, reliability, or completeness of these data. Data do no represent a legal description of the critical habitat boundary; refer to the textual description in the appropriate final rule for this species as published in the Federal Register.

 Federally Designated Critical Habitat for the San Marcos Salamander (Eurycea nana) [Figure: Houston Advanced Research Center using US FWS data]

Federally Designated Critical Habitat for the San Marcos Salamander (Eurycea nana) [Figure: Houston Advanced Research Center using US FWS data]. Click on map for larger image. 

Status: The San Marcos salamander is a state and federally listed (1980) threatened species. There is a refugium for this species at the San Marcos National Fish Hatchery and Technology Center. Quality and quantity of habitat is the most important requirement for maintaining a healthy population of San Marcos salamanders. The flow at which this species' habitat begins to decline is 80 cubic feet per second (cfs) or below. US Fish and Wildlife defines 60 cfs as the level for "take" of this species.

Resources:

Edwards Aquifer Authority, Draft Edwards Aquifer Habitat Conservation Plan

University of Texas, Herps of Texas, San Marcos Salamander

US Fish and Wildlife Service, Threatened Species Listing

US Fish and Wildlife Service, Endangered Species of the Edwards Aquifer

Texas Parks and Wildlife, San Marcos Salamander Species Profile

Texas Blind Salamander
Eurycea rathbuni

Texas Blind Salamander photo courtesy of Texas Parks and Wildlife

 [Photo: Texas Parks and Wildlife]

 

Description: The Texas blind salamander or Texas cave salamander, as it is sometimes known, is a small, fragile-limbed amphibian in the Eurycea genus of the lungless salamander family (Plethontidae) that lives in the darkness of the underground caves of the Edwards Aquifer. This salamander possesses a small pair of vestigial eyes hidden beneath white, translucent skin. This salamander grows up to 5.1 inches (13 cm) long and has a flat, broad heat and snout. It has bright red external gills, that it retains throughout its life. The Texas blind salamander has 4 toes on its front feet, 5 toes on its hind feet and 12 costal grooves.

Life History: The Texas blind salamander is a top predator in its habitat and hunts along the bottom of streams using water pressure waves created by its prey. It feeds on aquatic invertebrates such as snails, shrimp, and various insect and amphipod species. This species appears to breed year round, although little is known of its reproductive habits.

Habitat: The Texas blind salamander prefers deep, quiet pools in the streams of underground caves. It likes still waters and prefers habitats with an abundance of bottom-growth aquatic plants and matted algae.

Distribution: Eurycea rathbuni can be found in underground streams within the caverns of the San Marcos Pool of the Edwards Aquifer in Hays County, Texas. This species can only be seen at the surface when it is pushed out of the aquifer by spring flow.

The map below depicts the critical habitat for this species, as designated by the US Fish and Wildlife Service pursuant to the Endangered Species Act.

NOTE: No warranty is given, expressed or implied, as to the accuracy, reliability, or completeness of these data. Data do no represent a legal description of the critical habitat boundary; refer to the textual description in the appropriate final rule for this species as published in the Federal Register.

 

Federally Designated Critical Habitat for the Texas Blind Salamander (Eurycea rathbuni) [Figure: Houston Advanced Research Center using US FWS data]

Federally Designated Critical Habitat for the Texas Blind Salamander (Eurycea rathbuni) [Figure: Houston Advanced Research Center using US FWS data]. Click on map for larger image. 

 

Status: The Texas blind salamander is a state and federally listed (1967) endangered species. There is a refugium for this species at the San Marcos National Fish Hatchery and Technology Center. This species is sensitive to changes in water quality and quantity and impairments to either of these pose a serious threat to its existence. The spring flow required for "take" of this species as defined by the US Fish and Wildlife Service is 50 cubic feet per second (cfs). Other sources have found that habitat loss begins at 40 cfs or lower with serious potential for risk to this species at a spring flow of 20 cfs or lower.

Resources:

Texas Parks and Wildlife, Blind Salamander Profile

University of Michigan, Animal Diversity Web, Eurycea rathbuni

US Fish and Wildlife Service, Endangered Species Listing

US Fish and Wildlife Service, San Marcos National Fish Hatchery

US Fish and Wildlife Service, San Marcos Recovery Plan


 Print   
Privacy StatementTerms Of UseCopyright 2011 Houston Advanced Research Center

BorderBoxedBlueBoxedGrayBlueSmall width layoutMedium width layoutMaximum width layoutMaximum textMedium textSmall textBack Top!