[Photo: Texas Parks and Wildlife]

Texas Blind Salamander
Eurycea rathbuni

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]

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