The Texas blind salamander (Eurycea rathbuni) is a rare cave-dwelling troglobite amphibian native to San Marcos, Hays County, Texas, specifically the San Marcos Pool of the Edwards Aquifer. The salamander has blood-red external gills for absorbing oxygen from the water. The salamander's mature length is 13 cm (5 in). Its diet varies by what flows into its cave, including blind shrimp (Palaemonetes antrorum), snails, and amphipods.