Picture by Chad Thomas, Texas State University-San Marcos

Campostoma ornatum

Mexican stoneroller

Type Locality

Chihuahua River and a tributary a few miles long, Mexico (Girard 1856).

Etymology/Derivation of Scientific Name

Campo – curved and stoma – mouth, referring to U-shaped mouth; ornate – referring to ornamental coloration of breeding males (Scharpf 2005).

Synonymy

Campostoma ornatum Girard 1856:176; Burr (1976).

Campostoma pricei

Campostoma ornatum pricei Minckley 1973:141-142; McNatt 1974:275-276.

Characters

Maximum size: 114 mm (4.50 in) SL (Burr 1976).

Coloration: Burr (1976) noted an extreme variability in coloration both ontogenetically and among adults; most adults have mottled coloration; juveniles generally lack mottling but frequently have a dark mid-lateral stripe extending from snout to caudal peduncle and terminating in a small basicaudal spot; when mottling is developed in juveniles it is usually dorsal (within and above mid-lateral stripe); during non-breeding season, fins in both sexes are usually transparent but sometimes a black band may appear on the dorsal fin several months before the breeding season and continue through the season. Girard (1856) described coloration: upper regions purplish-black; lower regions golden-brown and yellow, with black spots distributed over the flanks; black patch at the base of all fins, otherwise the fins are orange or yellowish-brown. Burr (1976) described coloration of preserved breeding males: dorsal and anal fins often with a velvet-black medial band; pectoral and pelvic fins with black pigment heavily concentrated on the distal edges, becoming less intense proximally; black caudal spot lengthens transversely, often appearing as dark vertical band of pigment. In life, breeding male with distal half of dorsal fin milky white, basally fin is orange, and medially fin is velvet-black; anal fin similar to dorsal fin but with less black; caudal fin mostly milky white, with black and orange confined to the basal one-fourth; edge of shoulder girdle blackened (Burr 1976). In breeding females, a black band develops only on the dorsal fin (Burr 1976).

Counts: Pharyngeal teeth 0,4-4,0 (sometimes 1,4-4,1; Blair et al. 1957); 8 dorsal fin soft rays; 8 pelvic fin soft rays; 19 (18-20) caudal fin soft rays; 7 (rarely 8) anal fin soft rays; 16-18 pectoral fin soft rays; 14-20 moderately long, well separated gill rakers (Burr 1976). Burr (1976) listed the following counts for this species in the Rio Grande: 72 (65-78) lateral line scales; 55 (52-60) scales around body; 33 (30-37) predorsal scales; 28 (26-30) caudal peduncle scales; sum of lateral line and scales around body 127 (119-135); 28 (26-30) caudal peduncle scales.

Mouth position: Subterminal.

Body shape: Terete and stout.

Morphology: Cartilaginous ridge of lower jaw prominent and separated by a definite groove from lower lip (Hubbs et al. 1991). Breeding females with small tubercles on snout and above eye (Burr 1976).  Intestine long, loops only partially around air bladder (Burr 1976).

Distribution (Native and Introduced)

U.S. distribution: Texas and Arizona (Miller 1972; Williams et al. 1989; Scharpf 2005); species found in Rucker Canyon and Leslie Creek, AZ (McNatt 1974; Burr 1976). Endemic around the Sierra Tarahumara and east to the Big Bend area (United States and Mexico; Contreras-Balderas 1974).

Texas distribution: Species occurs primarily in Mexico and ranges into Texas in Rio Grande tributaries in Brewster and Presidio counties (Big Bend region; Hubbs 1940; Hubbs 1954; Hubbs et al. 1991).

Abundance/Conservation status (Federal, State, Non-government organizations)

Listed as Threatened by the Texas Parks and Wildlife Department. Edwards et al. (2002) reported that their collections of Mexican stonerollers in the Rio Conchos basin and middle Rio Grande, Mexico and U.S.A. supported Threatened status for the species. Listed as Threatened in Texas by Hubbs et al. (1991). Watch List status by the Texas Organization for Endangered Species (1988). Endangered in Arizona (U.S. Fish and Wildlife Service 1994). Williams et al. (1989) listed Special Concern status due to present or threatened destruction, modification, or curtailment of habitat or range, and other natural or manmade factors affecting continued existence. Listed as Threatened (Miller 1972). Endangered in Mexico (CONABIO 1997); Endangered status in Mexico may refer only to local populations as the species, in general, is widespread and regionally abundant in the country (Miller et al. 2005; Scharpf 2005). Hubbs and Wauer (1973) suggested that Mexican stonerollers in Tornillo Creek, Texas may be stressed by the presence of an introduced species, the plains killifish (Fundulus zebrinus). Prior to the introduction of plains killifish (first collected from Big Bend area in 1954), Mexican stonerollers were the most abundant fish in Tornillo Creek, Texas (Hubbs and Wauer 1973). Hubbs and Wauer (1973) indicated relative abundance of this species ranged from 0-17% in Tornillo Creek, Texas; occurring in only 5 of the 11 samples taken during the period from 1967-1970.

Habitat Associations

Macrohabitat: Creeks and rivers (Burr 1976; Hubbs et al. 1977). In Texas, found in clear tributaries in the Big Bend region, but not in adjacent streams (Hubbs 1957).

Mesohabitat: Collected in riffles, chutes, and pools from warm, clear to slightly turbid water over substrate consisting primarily of sand, pebbles, gravel, rock, and bedrock; rarely collected over mud; species most often found in shallow water; apparent preference for headwaters; largest collections taken from gravel runs or gravel-bottom pools; vegetation may or may not be present (Burr 1976; Burr 1980). Prefers gravel or rocky bottoms in clear, cool water (Contreras-Balderas 1974). McNatt (1974) found species to be abundant in pools of Rucker Canyon, Arizona, especially the deepest pools.

Biology

Spawning season: Winter and spring, in Tornillo Creek, Texas; young and breeding adults were present in January and half-grown young in May and June (Hubbs and Wauer 1973). Burr (1976) reported presence of males nearing full tuberculation in October collections from Texas; in Mexico, nuptial males and gravid females were present in collections from February – June.

Spawning habitat: Tributary creek habitats (Hubbs and Wauer 1973; Edwards et al. 2002).

Spawning Behavior: Pit-builders (Johnston 1999).

Fecundity: No information at this time.

Age at maturation: Burr (1976) examined nuptial males ranging in size from 55-105 mm (2.10-4.13 in) SL.

Migration: No information at this time.

Growth and Population structure: Males attain a greater length than females (Burr 1976). In small pools in Rucker Canyon, Arizona, McNatt (1974) reported at least three age-classes (possibly four) present.

Longevity: No information at this time.

Food habits: Herbivorous, bottom feeder (Contreras-Balderas 1974). Burr (1976) reported that cursory examination of intestinal contents suggest diet very similar to that of the central stoneroller (C. anomalum), consisting mainly of diatoms, bacteria and algae.

Phylogeny and morphologically similar fishes

Campostoma ornatum is a highly variable species displaying numerous presumably primitive features for the genus (Burr 1976; Burr 1980). Closest relative is the central stoneroller (Campostoma anomalum; Burr 1980). C. ornatum has more than 65 lateral line scales and the lower jaw length is greater than the eye length, while C. anomalum has fewer than 60 lateral line scales and the lower jaw length is less than the eye length (Hubbs et al. 1991). Burr (1976) listed major features in which C. ornatum diverges from C. anomalum as: development of smaller scales; loss of tubercles on the nape; development of head tubercles on the female; and more reduced body size.  C. ornatum is differentiated from other species of Campostoma by many morphological and biochemical characteristics (Buth and Burr 1978; Burr 1980). C. ornatum does not occur in sympatry with any other Campostoma species (Blum et al. 2008).

Host Records

Individuals from the Rio Trujillo (Mexico) were found to be heavily diseased with a monogenetic fluke, and large nematode worms were entwined throughout the intestines of adults (Burr 1976).

Commercial or Environmental Importance

McNatt (1974) reported predation on this species by the rainbow trout, Oncorhynchus mykiss.

References

Blair, W.F., A. P. Blair, P. Brodkorb, F.R. Cagle, and G.A. Moore. 1957. Vertebrates of the United States. McGraw-Hill Book Company, Inc., New York. 819 pp.

Blum, M.J., D.A. Neely, P.M. Harris, and R.L. Mayden. 2008. Molecular systematics of the cyprinid genus Campostoma (Actinopterygii: Cypriniformes): Disassociation between morphological and mitochondrial differentiation. Copeia 2:360-369.

Burr, B.M. 1976. A review of the Mexican stoneroller, Campostoma ornatum Girard (Pisces: Cyprinidae). San Diego Soc. Nat. Hist., Trans. 18(7):127-144.

Burr, B.M. 1980. Campostoma ornatum (Girard), Mexican stoneroller.  p. 146.  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.

Buth, D.G., and B.M. Burr. 1978. Isozyme variability in the cyprinid genus Campostoma. Copeia 1978(2):298-311.

Comision Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO). 1997. Oficio No. DOO.750,- 1415/97), la revision de la NOM-ECOL-059-1994, Norma Oficial Mexicana NOMECOL- 059-1994, que determina las especies y subespecies del flora y fauna silvestres terrestres y acuaticas en peligro de extincion, amnazadas raras y las sujetas a proteccion especial y qu establece especificaciones para su proteccion, Publicada en el D.O.F. de fecha 16 de mayo de 1994.

Contreras-Balderas, S. 1974. Speciation aspects and man-made community composition changes in Chihuahuan Desert fishes. In: Wauer, R.H., and D.H. Riskind (eds.). Transactions of the Symposium on the Biological Resources of the Chihuahuan Desert Rigion United States and Mexico. U.S. Department of the Interior, National Park Service Transactions and Proceedings Series (3):405-431.

Edwards, R.J., G.P. Garrett, and 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.

Girard, C.F. 1856. Researches upon the Cyprinoid fishes inhabiting the fresh waters of the United States of America, west of the Mississippi Valley, from specimens in the Museum of the Smithsonian Institution. Proceedings of the Academy of Natural Sciences of Philadelphia 8(5):165-213.

Hubbs, C. 1954. Corrected distributional records for Texas fresh-water fishes. Texas Journal of Science 1954(3):277-291.

Hubbs, C. 1957. Distributional patterns of Texas fresh-water fishes. Southwestern Naturalist 2:89-104.

Hubbs, C., and R. Wauer. 1973. Seasonal changes in the fish fauna of Tornillo Creek, Brewster County, Texas. The Southwestern Naturalist 17(4):375-379.

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. The Texas Journal of Science, Supplement 43(4):1-56.

Hubbs, C., R.R. Miller, R.J. Edwards, K.W. Thompson, E. Marsh, G.P. Garrett, G.L. Powell, D.J. Morris, and R.W. Zerr. 1977. Fishes inhabiting the Rio Grande, Texas and Mexico, between El Paso and the Pecos confluence. In: Johnson, R.R., and Jones, D.A. (eds.), Importance, Preservation and Management of Riparian Habitats: A symposium, USDA Forest Service, General Tech. Report, RM-43:91-97.

Hubbs, C.L. 1940. Fishes from the Big Bend region of Texas. Transactions of the Texas Academy of Science 23:3-12.

Johnston, C.E. 1999. The relationship of spawning mode to conservation of North American minnows (Cyprinidae). Environmental Biology of Fishes 55:21-30.

McNatt, R.M. 1974. Re-evaluation of the native fishes of the Rio Yaqui in the United States. Proc. West. Assoc. State Game and Fish Comm. 54:273-279.

Miller, R. R. 1972. Threatened freshwater fishes of the United States. Trans. Amer. Fish. Soc. 101(2):239–252.

Miller, R.R., W.L. Minckley, and S.M. Norris. 2005. Freshwater Fishes of Mexico. University of Chicago Press, Chicago, Illinois. 490 pp.

Minckley, W.L. 1973. Fishes of Arizona. Arizona Game and Fish Department. 293 pp.

Scharpf, C. 2005. Annotated checklist of North American freshwater fishes, including subspecies and undescribed forms, Part 1: Petromyzontidae through Cyprinidae. American Currents, Special Publication 31(4):1-44.

Texas Organization for Endangered Species (T.O.E.S.) 1988. Endangered, threatened, and watchlist of vertebrates of Texas. T.O.E.S. Publ. 6:1-16.

U.S. Fish and Wildlife Service. 1994. Yaqui Fishes Recovery Plan. USDI Fish and Wildlife Service, Albuquerque, New Mexico. 48 pp.

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: 1989. Fisheries 14(6):2-20.