Satan eurystomus

widemouth blindcat

Type Locality

Artesian well near San Antonio, Bexar County, Texas (Hubbs and Bailey 1947).

Etymology/Derivation of Scientific Name

“Satan”, Greek, meaning the Devil or Satan; “eury-“, Greek, meaning broad, wide; “stomus“, Greek, referring to the mouth.

Synonymy

Characters

Maximum size:  136.9 mm (Longley and Karnei 1979).

Coloration: White or pink (from blood pigments; Page and Burr 1991).

Counts: 19-20 anal rays (Page and Burr 1991).

Body shape:  Small body size compared to other ictalurid species (Langecker and Longley 1993). Well developed teeth on jaws; lips at corner of mouth thick (Hubbs and Bailey 1947; Hubbs et al. 1991). Lower jaw normal in shape, slightly shorter than upper jaw; broad, flat head and snout (Page and Burr 1991). No air bladder (Hubbs and Bailey 1947).

Mouth position: Transverse (Hubbs and Bailey 1947).

External morphology: Lateral line canals and pores on head well developed (Hubbs and Bailey 1947); no eyes; separate gill membranes with strong fold between them; long, high adipose fin; relatively short anal fin, rounded in outline; rear edge of caudal fin straight or slightly notched (Page and Burr 1991).

Distribution (Native and Introduced)

U.S. distribution:

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). Longley and Karnei (1979) provide detailed notes on distribution.

Abundance/Conservation status (Federal, State, NGO)

Endangered in its entire range (Hubbs et al. 1991; Warren et al. 2000).

Habitat Associations

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).

Biology

Spawning season:

Spawning location:

Reproductive strategy:

Fecundity:

Age at maturation:  Six specimens between the sizes of 51-90 mm SL were dissected, none of which appeared to be mature (Langecker and Longley 1993).

Migration: 

Longevity: Longley and Karnei (1979) note that many troglobites have longer life spans than their surface relatives.

Food habits: Opportunistic predator (Longley and Karnei 1979). Langecker and Longley (1993) examined the gut content of the wide mouth blindcat, and found mudlike substances as well as exoskeletons of crustaceans. Some individuals appeared starved: empty guts and considerably reduced fat deposits. Species primarily preys on lower vertebrates and may be the top carnivore of the Edwards Aquifer system (Langecker and Longley 1993). Potential prey abundant in habitat (Eigenmann 1919; Longley and Karnei 1979); remains of shrimp, amphipods and isopods found in stomachs, and possible predation on Trogloglanis pattersoni suggested (Longley and Karnei 1979). Suttkus (1961) reported an account mentioning “several dozen fresh-water shrimp” from 427 m deep well with blind catfish in San Antonio in June 1960.

Growth:

Phylogeny and morphologically similar fishes

The toothless blindcat (Trogloglanis pattersoni) lacks jaw teeth, has lower jaw curved into mouth, and fused gill membranes (Page and Burr 1991). Monotypic genus (Cooper and Longley 1980). Hubbs and Bailey (1947) concluded Satan and Pylodictis evolved from a common ancestor; Suttkus (1961) presented additional supportive evidence for this view. Pylodictis olivaris is the closest epigean relative of S. eurystomus (Taylor 1969; Lundberg 1982; Longley and Karnei 1979).

Host Records

A new nematode species, Rhabdochona longleyi sp. n. is described from the intestines of Satan Eurystomus, in Texas (Huffman 1988).

Commercial or Environmental Importance

Species is of considerable scientific interest as it represents on of the two known troglobitic catfish inhabiting subterranean waters in North America (Longley and Karnei 1979).

References

Cooper, J. E. and G. Longley. 1980. Satan eurystomus  (Hubbs and Bailey), Widemouth 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.

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.

Taylor, W.R. 1969. A revision of the catfish genus Noturus Rafinesque with an analysis of the higher groups of the Ictaluridae. U.S. Nat. Mus. Bull. 282:1-315.

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.