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Rio Lerma system at Piedad, Morelia (= Michoacan), Mexico (Bean 1880).
Etymology/Derivation of Scientific Name
Moxostoma congestum Jenkins (1980) stated that the Alamita Creek (Big Bend region) population was formerly known as M. congestum.
Scartomyzon austrinus Pyron (1999); Lyons et al. (2000); Harris et al. (2002); Mercado-Silva et al. (2002, 2006).
Moxostoma austrinum Robins and Raney (1957); Miller and Evans (1965); Edwards et al. (2002); Nelson et al. 2004:79, 204; Hubbs et al. 2008:27.
Maximum size: 380 mm SL (Jenkins 1980).
Coloration: Distal half of dorsal fin membranes dusky; caudal fin dusky; lower sides olive to yellow; caudal fin without a black streak (Hubbs et al. 2008).
Counts: 47-50 scales along the lateral line; dorsal fin rays 11 or 12 (Hubbs et al. 2008).
Body shape: Pectoral fin length less than head length; width of eye goes nearly 5.5 times into head length; dorsal fin base less than one-fourth of standard length (Hubbs et al. 2008).
External morphology: Lateral line complete and well developed in adults (Hubbs et al. 2008).
Internal morphology: Air bladder with 3 chambers (Hubbs et al. 2008).
Distribution (Native and Introduced)
U.S. distribution: Pacific coast drainages in Mexico to the mid-Rio Grande in Texas (Garrett and Edwards 2001; Hubbs et al. 2008). Rivers on both the Atlantic and Pacific slopes of Mexico (Harris et al. 2002); the Pacific slope of Mexico in Rio Armeria, Rio Ameca, Rio Grande de Santiago, and Rio San Pedro drainages. Atlantic slope, Rio Grande drainage, in Rio Conchos system, Chihuahua and Durango, Mexico, and Alamito Creek, Big Bend region, Texas (Contreras-Balderas 1974; Jenkins 1980; Edwards et al. 2002).
Texas distribution: Recorded from Texas in the Alamito Creek area of the Big Bend region (Jenkins 1980; Hubbs et al. 2008); in 1972, specimen (catalog number: USNM 00212109) collected from Hwy. 170, Alamito Creek, Presidio County, TX by J.G Saxon (Froese and Pauly 2008).
Abundance/Conservation status (Federal, State, NGO)
Special Concern status in Texas (Hubbs et al. 2008). Rare, possibly extirpated in the U.S.; uncommon in Mexico (Page and Burr 1991; Pyron 1999). Range contracting in the Rio Lerma basin, Mexico; species uncommon above the Autlan Valley in the Ayuquila River (Lyons et al. 1998).
Macrohabitat: Occupies small to large streams (Jenkins 1980).
Mesohabitat: Specimens found around rocks and boulders in torrential rapids of stream that may seasonally dry to isolated pools; also, found in moderately swift water (C.D. Barbour, pers. comm. in: Jenkins 1980). Benthic habitat (Mercado-Silva et al. 2002, 2006). Typically found in moderate to swiftly flowing waters (Miller and Evans 1965).
Spawning season: Spawns in spring, based on nuptial tuberculation (Jenkins 1980).
Spawning behavior: Egg layer (Mercado-Silva et al. 2002).
Age at maturation:
Growth and Population structure:
Food habits: Carnivore (> 75% animal material in stomach content; Lyons et al. 2000; Mercado-Silva et al. 2002, 2006).
Phylogeny and morphologically similar fishes
Moxostoma austrinum closely related to the gray redhorse (M. congestum; Robins and Raney; Jenkins 1970; Buth 1978; Jenkins 1980); the former species differs from the latter in the following characters (those of M. congestum in parentheses): the pectoral fin length is less than head length (vs. pectoral fin equal to head length), width of eye goes nearly 5.5 times into head length (vs. width of eye goes 4 to 5.5 times into head length), and M. austrinum has 47-50 scales along the lateral line (vs. 44-46 scales along the lateral line; Hubbs et al. 2008).
According to Jenkins (1980), M. austrinum exhibits the greatest morphological variation of all Moxostoma species.
Garrett and Edwards (2001) stated that Moxostoma austrinum in the Rio Grande may be a new, undescribed species.
Commercial or Environmental Importance
Species classified as sensitive, occurring only in good water quality and habitat (Lyons et al. 2000; Mercado-Silva et al. 2002, 2006).
Bean, T.H. 1880. Descriptions of two species of fishes collected by Prof. A. Duges in central Mexico. Proc. U.S. Natl. Mus. 2:302-305.
Buth, D.G. 1978. Biochemical systematics of the Moxostomatini (Cypriniformes, Catostomidae). Ph. D. dissertation, University of Illinois at Urbana-Champaign.
Contreras-Balderas, S. 1974. Speciation aspects and man-made community composition changes in Chihuahuan Desert fishes. pp. 405-431 in: Wauer, R.H., and D.H. Riskind (Eds.). Transactions of the Symposium on the Biological Resources of the Chihuahuan Desert Region United States and Mexico. U.S. Department of the Interior, National Park Service Transactions and Proceedings Series No. 3.
Edwards, R.J., G.P. Garrett, E. Marsh-Matthews. 2002. Conservation and status of the fish communities inhabiting the Conchos basin and middle Rio Grande, Mexico and U.S.A. Reviews in Fish Biology and Fisheries 12:119-132.
Froese, R. and D. Pauly. Editors. 2008. FishBase. World Wide Web electronic publication.www.fishbase.org, version (07/2008).
Garrett, G.P., and R.J. Edwards. 2001. Chapter 5: Regional ecology and environmental issues in west Texas. pp. 56-65 in: R. E. Mace, W.F. Mullican III, and E.S. Angle (Eds.). Aquifers of West Texas. Texas Water Development Board Report.
Harris, P.M., R.L. Mayden, H.S. Espinosa Perez, and F. Garcia de Leon. 2002. Phylogenetic relationships of Moxostoma and Scartomyzon (Catostomidae) based on mitochondrial cytochrome b sequence data. Journal of Fish Biology 61:1433-1452.
Hubbs, C., R.J. Edwards, and G.P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement, 2nd edition 43(4):1-87.
Jenkins, R.E. 1970. Systematic studies of the catostomid fish tribe Moxostomatini. Cornell University, Ithaca, New York. 799 pp.
Jenkins, R.E. 1980. Moxostoma austrinum (Bean), West Mexican redhorse. p. 413. In: D. S. Lee, C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister & J. R. Stauffer, Jr. (eds.), Atlas of North American freshwater fishes, North Carolina State Museum of Natural History, Raleigh, 854 pp.
Lyons, J., A. Gutierrez-Hernandez, E. Diaz-Pardo, E. Soto-Galera, M. Medina-Nava, and R. Pineda-Lopez. 2000. Development of a preliminary index of biotic integrity (IBI) based on fish assemblages to access ecosystem condition in the lakes of central Mexico. Hydrobiologia 418(1):57-72.
Lyons, J., G. Gonzalez-Hernandez, E. Soto-Galera, and M. Guzman-Arroyo. 1998. Decline of freshwater fishes and fisheries in selected drainages of west-central Mexico. Fisheries 23(4):10-18.
Mercado-Silva, N., J. Lyons, E. Diaz-Pardo, A. Gutierrez-Hernandez, C.P. Ornelas-Garcia, C. Pedraza-Lara, and M. J. Vander Zaden. 2006. Long-term changes in the fish assemblage of the Laja River, Guanajuato, central Mexico. Aquatic Conservation: Marine and Freshwater Ecosystems 16:533-546.
Mercado-Silva, N., J.D. Lyons, G. Salgado-Maldonado, and M. Medina-Nava. 2002. Validation of a fish-based index of biotic integrity for streams and rivers of central Mexico. Reviews in Fish Biology and Fisheries 12:179-191.
Miller, R.J., and H.E. Evans. 1965. External morphology of the brain and lips in catostomid fishes. Copeia 1965(4):467-487.
Page, L. M. & B. M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston, Massachusetts. 432 pp.
Pyron, M. 1999. Relationships between geographical range size, body size, local abundance, and habitat breadth in North American suckers and sunfishes. Journal of Biogeography 26:549-558.
Robins, C.R., and E.C. Raney. 1957. The systematic status of the suckers, of the genus Moxostoma from Texas, New Mexico, and Mexico. Tulane Studies in Zoology 5:291-318.