Artesian well, San Antonio, Bexar County, Texas (Eigenmann 1919).
Etymology/Derivation of Scientific Name
“Troglo-“, Greek, meaning a hole or cave; “glanis”, Greek, meaning a kind of fish; “pattersoni”, named for Professor J.T. Patterson, of the University of Texas, who secured the Trogloglanis pattersoni specimen referred to by Eigenmann (1919) from an artesian well in San Antonio, Texas.
Maximum size: 10.4 cm (Page and Burr 1991); standard length of the 47 known specimens of Trogloglanis pattersoni ranges from 16-89 mm (Langecker and Longley 1993).
Coloration: White or pink body, red mouth (from blood pigments; Page and Burr 1991).
Counts: 16-17 anal rays (Page and Burr 1991).
Body shape: Small compared to other ictalurid species (Langecker and Longley 1993); lips at the corner of mouth thin (Hubbs et al. 1991); short lower jaw curved upward and into mouth; snout overhangs mouth (Page and Burr 1991).
Mouth position: Ventrally placed, toothless sucker-mouth (Langecker and Longley 1993). Greatly inverted (Hubbs and Bailey 1947).
External morphology: No eyes (Hubbs et al. 1991); poor development of lateral-line system; relatively short maxillary barbels (Lundberg 1982); short lower gill membranes with barely visible fold between them; long, high adipose fin joined to caudal fin; short anal fin, rounded in outline; rear edge of caudal fin straight or slightly notched; no air bladder (Page and Burr 1991).
Distribution (Native and Introduced)
Texas distribution: Restricted to 5 artesian wells penetrating the San Antonio Pool of the Edwards Aquifer (Edwards Limestone, Lower Cretaceous) in the vicinity of San Antonio (Cooper and Longley 1980; Hubbs et al. 1991; Page and Burr 1991; Warren et al. 2000).
Abundance/Conservation status (Federal, State, NGO)
Endangered in its entire range (Hubbs et al. 1991; Warren et al. 2000).
Macrohabitat: Subterranean waters (Page and Burr 1991).
Mesohabitat: Found at depths of 305-582 m (Cooper and Longley 1980; Hubbs et al. 1991); in water temperature 27 degrees C (wells with 24 degree C water in north and northwestern Bexar County; Cooper and Longley 1980). This species, which lacks an air bladder, lives under great hydrostatic pressure (Hubbs and Bailey 1947).
Reproductive strategy: Lundberg (1982) suggested that olfaction may primarily be concerned with the localization of mates in this species.
Fecundity: Ovaries of the largest specimen dissected (SL 80 mm) contained approximately 200 oocytes at different stages of maturation (maximum size was 0.5 mm; Langecker and Longley 1993).
Age at maturation: Female specimens (SL > 60 mm) frequently had minute eggs (Langecker and Longley 1993).
Food habits: When gut contents examined, mudlike substances found; study suggests detrivorous nutrition; most individuals appeared well fed, but some appeared starved: empty guts and considerably reduced fat deposits; species can be assumed to be in restless, random search for food on the bottom, digesting any organic compound coming in contact with enlarged lips of specialized mouth (Langecker and Longley 1993). Potential prey abundant in habitat (Eigenmann 1919; Longley and Karnei 1979); species feeding on fungal growths and dead or dying organisms in soft substrate (Longley and Karnei 1979).
Phylogeny and morphologically similar fishes
Satan eurystomus has jaw teeth, the lower jaw is normal in shape, has separate gill membranes, and 19-20 anal rays (Page and Burr 1991). Trogloglanis pattersoni is in a monotypic genus (Cooper and Longley 1980). Eigenmann (1919) suggested derivation from Noturus. Hubbs and Bailey (1947) felt derivation from an Ameirus type most plausible, but pointed out Trogloglanis most highly specialized genus of family. Suttkus (1961) said it resembled members of genus Ictalurus, especially I. melas "in the shape of the dermethmoid.
A new nematode species, Rhabdochona longleyi sp. n. is described from the intestine of Trogloglanis pattersoni, in Texas (Huffman 1988).
Commercial or Environmental Importance
Cooper, J. E. and G. Longley. 1980. Trogloglanis pattersoni (Eigenmann) Toothless blindcat. pp 474 In: D.S. Lee et al. Atlas of North American Freshwater fishes. N.C. State Mus. Nat. Hist., Raleigh, i-r + 854.
Eigenmann, C. 1919. Trogloglanis pattersoni, a new blind fish from San Antonio, Texas. Proc. Amer. Philos. Soc. 58:397-400.
Hubbs, C., and R.M. Bailey. 1947. Blind catfishes from artesian waters of Texas. Occas. Pap. Mus. Zool. Univ. Mich. 499:1-17.
Hubbs, C., R. J. Edwards and G. P. Garrett. 1991. An annotated checklist of freshwater fishes of Texas, with key to identification of species. Texas Journal of Science, Supplement 43(4):1-56.
Huffman, M. F. 1988. Rhabdochona longleyi sp. n (Nematoda: Rhabdochonidae) from blind catfishes, Trogloglanis pattersoni and Satan Eurystomus (Ictaluridae) from the subterranean waters of Texas. Folia Parasitol (Praha) 35(3):235-243.
Langecker, T. G., and G. Longley. Morphological Adaptations of the Texas Blind Catfishes Trogloglanis pattersoni and Satan eurystomus (Siluriformes: Ictaluridae) to Their Underground Environment. Copeia 1993(4):976-986.
Longley, G., and H. Karnei. 1979. Status of Trogloglanis pattersoni Eigenmann, the toothless blindcat, and status of Satan eurystomus Hubbs and Bailey, the widemouth blindcat. Endangered Species Report, U.S. Fish and Wildlife Service, Albuquerque, NM.
Lundberg, J.G. 1982. The comparative anatomy of the toothless blindcat, Trogloglanis pattersoni Eigenmann, with a phylogenetic analysis of the ictalurid catfishes. Misc. Publ. Univ. Michigan 163:1-85.
Page, L. M., and B. M. Burr. 1991. A Field Guide to Freshwater Fishes of North America, north of Mexico. Houghton Mifflin Company, Boston, 432 pp.
Suttkus, R.D. 1961. Additional information about blind catfishes from Texas. Southwestern Naturalist 6:55-64.
Warren, L. W., Jr., B. M. Burr, S. J. Walsh, H. L. Bart, Jr., R. C. Cashner, D. A. Etnier, B. J. Freeman, B. R. Kuhajda, R. L. Mayden, H. W. Robison, S. T. Ross, and W. C. Starnes. 2000. Diversity, Distribution, and Conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.