The widemouth blindcat is found in the deep artesian Edwards Aquifer in Bexar County in the south and eastern part of San Antonio. Hubbs and Bailey named this fish Satan eurystomus in 1947. The species has been reported from five artesian wells that obtain water from the aquifer at depths between 1,350 and 2,000 feet. This species shares habitat with Trogloglanis pattersoni, the toothless blindcat. The first specimens seen by scientists were in the collections of the Witte Museum. No information was available with the specimens regarding where, when, or by whom they were collected. During a study of Bexar County groundwater fauna from March 1977 to June 1978, Longley and Karnei collected fourteen specimens of this fish. This fish generates considerable scientific interest since it is one of two known troglobitic catfish from North America. No external vestige of eyes is present. The fish is without pigment or an air bladder. The fish apparently feeds on any of the other inhabitants of its watery, dark domain that it can catch. It is a carnivorous fish that has adapted to life in the dark underground waters. The maximum length known is approximately 5.5 inches. This fish is threatened by overpumping of the aquifer in the area where it is found. Numerous fish are lost to the surface by discharge from wells in the area. In addition, drawdown of the aquifer in the area threatens to allow the intrusion of poor quality water into the habitat of the fish. Approximately forty species of macroinvertebrates inhabit the same dark domain of the widemouth blindcat and its relative the toothless blindcat. All of these species make up a highly unique ecosystem with greater diversity than any other known in the world today.