The San Marcos salamander is a small, slender salamander with moderately large eyes and well-developed and highly pigmented gills. Like other central Texas Eurycea salamanders, the San Marcos salamander is strictly aquatic and retains its external gills throughout life. The San Marcos salamander is endemic to the San Marcos Springs and nearby surface and subterranean aquatic habitats. At the surface, this species occurs primarily from rocky habitats and submerged aquatic vegetation. One individual was found from a nearby flowing artesian well, which indicates that the species also can occur in the aquifer. Because of its reliance on groundwater, groundwater quantity and quality are major threats to the species. Human modifications that affect surface habitat are also a threat to the species. The San Marcos salamander was listed as threatened on July 14, 1980. The USFWS works with their partners to ensure the springs continue to provide clean and healthy freshwater to their microhabitats for this species.

Source: USFWS