While our physical offices are closed until further notice in accordance with Austin's COVID-19 "stay home-work safe" order, the Handbook of Texas will remain available at no-cost for you, your fellow history enthusiasts, and all Texas students currently mandated to study from home. If you have the capacity to help us maintain our online Texas history resources during these uncertain times, please consider making a 100% tax-deductible contribution today. Thank you for your support of TSHA and Texas history. Donate Today »


Glenn Longley

TOOTHLESS BLINDCAT. The toothless blindcat is a troglobitic catfish of the family Ictaluridae. It was named Trogloglanis pattersoni by Eigenmann in 1919. It is considered to be the most highly specialized member of the family. It is unique in having no eyes, no pigment, no air bladder, and a sucker-type mouth. It is found only in southern Bexar County at depths of 1,350 to 2,000 feet below the surface, in the water-filled caverns of the Balcones Fault Zone Edwards Aquifer. It was discovered originally by George W. Brackenridge in one of his wells. Later a Belgian farmer, Josef Boecke, noticed the fish in the discharge from his artesian irrigation well near the site of the present Joe Freeman Coliseum in San Antonio. In 1977–78 a study of the Bexar County groundwater fauna was conducted by Glenn Longley and Henry Karnei. They collected twenty-six specimens of this species and gained much information regarding its ecosystem. The toothless blindcat apparently feeds on organic materials in the water-filled caverns of the aquifer. It is possibly dependent on having the anaerobic "bad water" nearby. It is suggested that the species is dependent on the sulfur bacteria-based food chain that develops in the saline, sulfurous zone found adjacent to the good-quality Edwards Aquifer. It is unable to withstand the absence of dissolved oxygen but may make short excursions into that area to feed. It is likely that there is a sharp division (halocline) between the good water and "bad water" of the aquifer in this area. Overpumping of the aquifer presents a threat to the species. In the 1990s the world's largest water well was drilled close to the known habitat of the fish. Drawing down the aquifer poses a threat to the toothless blindcat by possibly allowing the poor-quality "bad water" to replace good-quality water where the fish now resides.

Lazare Botosaneanu, ed., Stygofauna Mundi: A Faunistic, Distributional, and Ecological Synthesis of the World Fauna Inhabiting Subterranean Waters (Including the Marine Interstitial) (Leiden, Netherlands: Brill, 1986). Glenn Longley, "The Edwards Aquifer: Earth's Most Diverse Groundwater Ecosystem?," International Journal of Speleology 11 (1981). G. Longley and H. Karnei, Status of Trogloglanis pattersoni Eigenmann, the Toothless Blindcat (Endangered Species Report 5, Albuquerque, New Mexico: U.S. Fish and Wildlife Service, 1979).

Image Use Disclaimer

All copyrighted materials included within the Handbook of Texas Online are in accordance with Title 17 U.S.C. Section 107 related to Copyright and “Fair Use” for Non-Profit educational institutions, which permits the Texas State Historical Association (TSHA), to utilize copyrighted materials to further scholarship, education, and inform the public. The TSHA makes every effort to conform to the principles of fair use and to comply with copyright law.

For more information go to: http://www.law.cornell.edu/uscode/17/107.shtml

If you wish to use copyrighted material from this site for purposes of your own that go beyond fair use, you must obtain permission from the copyright owner.


The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this article.

Handbook of Texas Online, Glenn Longley, "TOOTHLESS BLINDCAT," accessed July 09, 2020, http://www.tshaonline.org/handbook/online/articles/tft01.

Uploaded on June 15, 2010. Published by the Texas State Historical Association.
visit the mytsha forums to participate

View these posts and more when you register your free MyTSHA account.

Call for Papers: Texas Center for Working-Class Studies Events, Symposia, and Workshops
Hi all! You may be interested in this call for papers I received from the Texas Center for Working-Class Studies at Collin College...

Katy Jennings' Ride Scholarly Research Request
I'm doing research on Catherine Jennings Lockwood, specifically the incident known as "Katy Jennings' Ride." Her father was Gordon C. Jennings, the oldest man to die at the Alamo...

Texas Constitution of 1836 Co-Author- Elisha Pease? Ask a Historian
The TSHA profile of Elisha Marshall Pease states that he wrote part of the Texas Constitution although he was only a 24 year-old assistant secretary (not elected). I cannot find any other mention of this authorship work by Pease in other credible research about the credited Constution authors...