Picture by Chad Thomas, Texas State University-San Marcos
Rio Pecos, Texas (Girard 1859).
Etymology/Derivation of Scientific Name
Ictalurus, Greek, meaning “fish cat;” (Pflieger 1997); lupus, Latin, meaning “a wolf”.
Pimelodus lupus Girard 1859:211.
Ictalurus lupus Jordan and Gilbert 1882:107; Gilbert and Burgess 1980:440; Kelsch and Hendricks 1986:646.
Amerurus lupus Evermann and Kendall 1894:97; Jordan and Evermann 1896-1900:137; Cockerell 1908:163.
Maximum size: In captivity, males have attained 431 mm TL, and females 328 mm TL (Dr. Paul Turner, pers. comm. in: Sublette et al. 1990).
Coloration: Back and sides olivaceous with a few scattered, diffuse black spots on the sides; abdomen silvery (Sublette et al. 1990).
Counts: 23-26 anal fin rays (Hubbs et al. 1991). Dorsal rays 6 (5-8), 1 dorsal spine, pectoral rays 8-10, 1 pectoral spine, pelvic rays 8, anal rays 23 (20-26), caudal rays 17-26 (Sublette et al. 1990).
Body shape: Head rounded (Hubbs et al. 1991); dorsal view of snout rounded; eye closer to dorsum of head than to venter (Sublette et al. 1990). In New Mexico, fish are broader than their counterparts in Texas (Kelsch 1995).
Mouth position: Subterminal, upper jaw projecting (Sublette et al. 1990).
External morphology: Pectoral spine length much less than caudle peduncle depth; pectoral fin spine contained more than five times in standard length; caudal fin deeply forked; adipose fin free at tip, not joined to caudal fin (Hubbs et al 1991). Lateral line complete, terminating at the base of the caudal rays; thin, short barbels located immediately in front of the posterior nostrils; maxillary barbels exceed length of the head; chin with a transverse row of four barbels, median two barbels shorter than the outer ones (Sublette et al. 1990).
Internal morphology: Premaxillary band of teeth on upper jaw without a lateral backward extension on each side (Hubbs et al. 1991).
Distribution (Native and Introduced)
U.S. distribution: Currently inhabits clear, headwater streams in the Rio Grande drainage of New Mexico, Texas and Mexico, and Gulf slope streams of northeastern Mexico (Kelsh and Hendricks 1986; Sublette et al. 1990). Native to the Pecos and Rio Grande basins of Texas and New Mexico (Hubbs et al. 1991).
Texas distribution: Native to the Pecos and Rio Grande basins of Texas; once found in the upper Nueces, San Antonio, Guadalupe, and Colorado basins, but appears to be extirpated from these systems (Kelsch and Hendricks 1990). Relatively uncommon but persistent in Independence Creek (tributary of the lower Pecos River, Rio Grande drainage) collections (Bonner et al. 2005). Edwards et al. (2002) found the species in the Rio Grande below the Rio Conchos confluence downstream through the lower canyons of the Big Bend region (in low abundance). Platania (1990) reported collection of 23 specimens only at Hinds Creek on upper San Felipe Creek in Del Rio. Species found in the Devils River, with relative abundance of less than 1% (Harrell 1978).
Abundance/Conservation status (Federal, State, NGO)
Hubbs et al. (1991) considered species to be of special concern in Texas, and noted that it is listed on the Texas Organization of Endangered species watch list. Warren et al. (2000) considered populations extinct in a study area including the Colorado River unit, the Nueces River unit, and the San Antonio Bay unit (including minor coastal drainages west of the Colorado River to the mouth of the Nueces River). Species of Special Concern in Texas and New Mexico (Williams et al. 1989).
Macrohabitat: Observations indicate species occupies clear streams and rivers with moderate gradients (Yates et al. 1984; Sublette et al. 1990).
Mesohabitat: Abundant in deep runs in the upper reaches of Independence Creek, Texas (Bonner et al. 2005). In Pinto Creek, Texas, a small, spring-fed tributary of the Rio Grande, this species was more commonly encountered in primarily downstream stations (Edwards 2003; Garrett et al. 2004). Specimen found in a large spring run in the upper Guadalupe River, Texas (Hubbs et al. 1953). In New Mexico, species occurs in alternating sections of shallow riffles and deep pools (Yates et al. 1984).
Detailed accounts of spawning behavior and ecological requirements for Ictalurus lupus are lacking; however I. lupus may be similar to the channel catfish ( I. punctatus; Gilbert and Burgess 1980;Yates et al. 1984; Kelsh 1995; Sublette et al. 1990).
Age at maturation:
Food habits: Particulate herbivore and benthic invertivore (following trophic guild classification of Goldstein and Simon 1999), and based on large amounts (96% by weight) of algae and aquatic invertebrates found in the gut contents; however presence of fish and terrestrial arthropods suggested carnivorous and opportunistic feeding behavior (Littrell et al. 2003). Gut contents of Ictalurus lupus from Independence Creek (Pecos River drainage) and Dolan Creek (Devils River drainage) of west Texas were examined and found to consist of algae and detritus (85%), aquatic insects (9%), crustaceans (3%) and other aquatic and terrestrial organisms (3%); aquatic insects and crustaceans were more prevalent in younger fish than older fish (Littrell et al. 2003)
Phylogeny and morphologically similar fishes
Kelsch (1995) found that overall, Ictalurus lupus tended to be broader, have shorter spines, and have a shorter anal fin base than the channel catfish (I. punctatus) when measurements were adjusted for body size. I. lupus most closely resembles the channel catfish (I. punctatus) but differs from the latter by fewer anal fin rays (I. lupus 20-26, I. punctatus 25-31) and a moderately forked caudal fin with bluntly pointed lobes; depth of the caudal fork not always a reliable mean of separating the two species as older specimens of both I. lupus and I. punctatus tend to have eroded lobes of the caudal fin caused by scooping out spawning nests and by normal abrasion (Sublette et al. 1990). Apparently much smaller maximum size for I. lupus than for related I. punctatus (Gilbert and Burgess 1980). Yates et al. (1984) and Kelsch and Hendricks (1986) reported Ictalurus lupus X I. puntatus hybrids; McClure-Baker (2002) noted that collections from Independence Creek, Devils River, and Pinto Creek, Texas clearly indicate past or on going hybridization.
Commercial or Environmental Importance
Habitat alterations and competative interactions with the sympatric channel catfish (Ictalurus punctatus) led to extirpation of I. lupus from Gulf slope streams of Texas (Kelsh and Hendricks 1990). According to Hubbs and Garrett (1990) Ictalurus lupus found in the region of the Devils River and proximate streams in Texas and Coahuila have been adversely affected by reservoir construction as well as spring drying, and these factors remain long-term threats.
[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Calovich and Branson (1964).]
Bonner, T.H., C. Thomas, C.S. Williams, and J.P. Karges. 2005. Temporal assessment of a west Texas stream fish assemblage. The Southwestern Naturalist 50(1):74-106.
Calovich, F.E., and B.A. Branson. 1964. The supraethmoid-ethmoid complex in the American catfishes, Ictalurus and Pylodictis. American Midland Naturalist 71(2):335-343.
Cockerell, T.D.A. 1908. The fishes of the Rocky Mountain Region. Univ. Colo. Stud., Ser. Biol. 5:159-178.
Edwards, R.J. 2003. Ecological profiles for selected stream-dwelling fishes IV. Report to the Texas Water Development Board. 19 pp.
Edwards, R.J., G.P. Garrett, and E. Marsh-Matthews. 2002. Conservation and status of the fish communities inhabiting the Rio Conchos basin and middle Rio Grande, Mexico and U.S.A. Reviews in Fish Biology and Fisheries 12(2/3):119-132.
Evermann, B. W. and W. C. Kendall. 1894. 3. The fishes of Texas and Rio Grande Basin, considered chiefly with reference to their geographic distribution. Bull. U. S. Fish. Comm. (1892) 12:57-121, pls. 10.
Garrett, G.P., R.J. Edwards, and C. Hubbs. 2004. Discovery of a new population of Devils River minnow (Dionda diaboli), with implications for conservations of the species. The Southwestern Naturalist 49(4):435-441.
Gilbert, C.R., and G.H. Burgess. 1980. Ictalurus lupus (Girard), Headwater catfish. pp. 440 in D. S. Lee et al., Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.
Girard, C. 1859. Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean. Volume X, Fishes. Ex. Doc. No. 91, A.O.P. Nicholson Printer, Washington, D.C.
Goldstein, R.M., and T.P. Simon. 1999. Toward a united definition of guild structure for feeding ecology of North American freshwater fishes. pp. 123-202 in T.P. Simon, editor. Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press, Boca Raton, Florida. 671 pp.
Harrell, H.L. 1978. Response of the Devils River (Texas) fish community to flooding. Copeia 1978(1):60-68.
Hubbs, C., and G.P. Garrett. 1990. Reestablishment of Cyprinodon eximius (Cyprinodontidae) and status of Dionda diaboli (Cyprinidae) in the vicinity of Dolan Creek, Val Verde Co., Texas. The Southwestern Naturalist 35(4):446-448.
Hubbs, C., R.A. Kuehne, and J.C. Ball. 1953. The fishes of the upper Guadalupe River. The Texas Journal of Science 5(2):216-244.
Hubbs, C., R. J. Edwards, and G. P. Garrett. 1991. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science 43(4):1-56.
Jordan, D. S. and B. W. Evermann. 1896-1900. The fishes of North and Middle America. Parts I-IV. Bull. U.S. Nat. Mus. No. 37, pp. 1-3313.
Jordan, D. S. and C. H. Gilbert. 1882. Synopsis of the fishes of North America. U. S. Nat. Mus. Bull. 16:1-1018.
Kelsch, S.W. 1995. Patterns of morphometrics variation in the channel and headwater catfishes. Transactions of the American Fisheries Society 124:272-279.
Kelsch, S.W., and F.S. Hendricks. 1986. An electrophoretic and multivariate morphometric comparison of the American catfishes Ictalurus lupus and I. punctatus. Copeia 1986(3):646-652.
Kelsch, S. W., and F. S. Hendricks. 1990. Distribution of the headwater catfish Ictalurus lupus (Osteichthyes: Ictaluridae). Southwestern Naturalist 35:292-297.
McClure-Baker, S.A. 2002. Status and genetic structure of the channel catfish complex (genus Ictalurus) in New Mexico and Texas. M.S. Thesis, Oklahoma State University, Stillwater. 37 pp.
Pflieger, W.L. 1997. The Fishes of Missouri. Missouri Department of Conservation, Jefferson City. 372 pp.
Platania, S.P. 1990. The ichthyofauna of the Rio Grande drainage, Texas and Mexico, from Boquillas to San Ygnacio. Final Report to the U.S. Fish and Wildlife Service, Office of Endangered Species, Albuquerque, New Mexico. 100 pp.
Sublette, J.E., M.D. Hatch, and M. Sublette. 1990. The Fishes of New Mexico. University of New Mexico Press, Albuquerque. 393 pp.
Warren, M.L., 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.
Williams, J.E., J.E. Johnson, D.A. Hendrickson, S. Contreras-Balderas, J.D. Williams, M. Navarro-Mendoza, D.E. McAllister, and J.E. Deacon. 1989. Fishes of North America Endangered, Threatened, or of Special Concern. Fisheries 14(6):2-20.
Yates, T.L., M.A. Lewis, and M.D. Hatch. 1984. Biochemical systematics of three species of catfish (Genus Ictalurus) in New Mexico. Copeia 1984(1):97-101.