Texas Blind Salamander

The Texas blind salamander is a cave-dwelling salamander known only from the water-filled passages of the Edwards Aquifer near San Marcos, Texas, first discovered when it turned up in a drilled well in the early twentieth century. It is pale pink to white, lacking pigment, with only vestigial eyes hidden beneath its skin, and it retains prominent feathery external gills throughout its life, never transforming into a lunged, terrestrial adult, a pattern called paedomorphosis common among aquatic cave salamanders. Long, thin legs and an elongated, flattened head are thought to help it navigate and forage by touch and vibration in the total darkness of its underground habitat. Because its entire known range depends on a single aquifer system vulnerable to pollution, over-pumping, and drought, it is federally listed as an endangered species in the United States.