Devils Hole Pupfish (Cyprinodon diabolis)

The Devils Hole pupfish is endemic to Devils Hole, a single geothermal pool in Ash Meadows, Nye County, Nevada—the smallest range of any vertebrate. Listed as endangered under the ESA since 1967, the species is protected by the National Park Service and managed cooperatively with the Nevada Department of Wildlife and USFWS. Population fluctuates seasonally but typically numbers fewer than 200 individuals. All fishing or collection is strictly prohibited.