 San Marcos salamander

The San Marcos salamander ("Eurycea nana") is a small species of aquatic, lungless salamander native to the United States, endemic to Spring Lake and a small region of the headwaters of the San Marcos River near Aquarena Springs, in Hays County, Texas.It is one to two inches long, with a slender body and external gills, and is a reddish-brown in color.