your internet guide to all things catfish
by Garold W. Sneegas & Dean A. Hendrickson, Ph.D.
the city of San Antonio Texas lies a vast aquifer known
as the Edwards (Balcones Fault Zone) Aquifer. Two rare
and unusual catfish reside in the aquifer, Satan
eurystomus, the widemouth blindcat and Trogloglanis
pattersoni, the toothless blindcat. They are the
only known troglobitic catfish in the United States.
The only specimens of both species ever collected have
come from deep (1,200' to 1,500') artesian wells within
the city of San Antonio itself and parts of southern
The toothless blindcat is the most specialized catfish known. It's closest surface relative is Ictalurus melas, the black bullhead. It has evolved a unique suckermouth with papery thin jaws and no teeth. The upper lip has modified parallel folds of soft ridges. The lower lip is small and turned into the mouth. No other catfish has this type of mouth. The lateral line system is not as well developed as the widemouth blindcat's system. The olfactory senses of the toothless blindcat however are more developed. Nostrils in the toothless blindcat are larger and the anterior nostrils have a specialized flap that enhances water flow. Black bullheads have taste buds, cells with cilia (short hair-like extensions) covering their external skin. Microscopic examination of the toothless blindcat's skin revealed a densely packed covering of taste bud cells. The external skin of the widemouth blindcat lacks these cells. The toothless blindcat probably feeds on dead or dying invertebrates and a fungus commonly found in the Edwards Aquifer.
The extreme inaccessibility
to the blindcats habitat in addition to water quality
monitoring by state and federal agencies, has protected
the habitat of these two unique species. The biggest
threat to the blindcats is probably over-pumping the
aquifer beyond its' recharge capability. Drawing down
the aquifer could cause the sulfurous "Bad Water"
zone to encroach into and replace the "Good Water"
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