By Melissa Munger
Geographic Range
The Texas Cave Salamander is limited to the San Marcos, Texas area. (Bockstanz and Cannatella, 1999)
Habitat
Eurycea rathbuni is only found in subterranean water systems in Edwards Plateau in Texas. The Edwards Plateau is characterized by springs and caves and lies at an elevation of 600-750 meters. It has been found in wells but is usually restricted to caves (Duellman 1999). (Deullman, 1999)
These animals are found in the following types of habitat:
temperate 
; freshwater .
Other:
caves.
Physical Description
Eurycea rathbuni is characterized by a very broad, flat head and snout. The four limbs are very thin and elongate. The tail is laterally compressed and finned, tapering at its end. The eyes are vestigial and lie beneath the animal's skin. External gills are bright red and always present. The forelimbs have four digits while the hind limbs have five. Eurycea rathbuni is neotenic and thus bright red gills are present throughout the lifecycle. It has twelve costal grooves as well. Adults range in length from 3.25 to 5.375 inches (University of Texas; Potter and Sweet 1981). (Potter and Sweet, 1981)
Some key physical features:
ectothermic ; heterothermic ; bilateral symmetry .
Sexual dimorphism: sexes alike.
Reproduction
Little is known about the reproduction of Eurycea rathbuni. The species is known to be acyclic with females maturing and reproducing throughout the year, unresponsive to seasonal cues. This breeding cycle is typical of many cave dwelling species (Lofts 1974). Breeding of this species has been observed in the laboratory. The females assumes an active role in stimulating the male to mate. Her behavior is characterized by rubbing her chin along the male's back. If this fails to stimulate the male then she may scratch at him or fan her tail at him. She may even resort to nipping at his sides if he further ignores her advances. The male will deposit a spermatophore on a rock or substrate and the female will then pick it up with her cloaca (Bechler 1988).
Key reproductive features:
iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (internal ); oviparous .
Behavior
Little is known about the behavior of this species.
Food Habits
Little is known about this species feeding habits and methods. It may feed on snails, shrimp, and amphipods (University of Texas).
Economic Importance for Humans: Negative
Eurycea rathbuni does not negatively affect humans.
Economic Importance for Humans: Positive
This salamander is not a resource for humans.
Conservation Status
Eurycea rathbuni is listed as endangered under the U.S. Endangered Species Act (Duellman 1999). Its extremely limited range makes it a vulnerable species. (Deullman, 1999)
For More Information
Find Eurycea rathbuni information at
Contributors
Melissa Munger (author), Michigan State University.
James Harding 
(editor), Michigan State University.
