Picture by Chad Thomas, Texas State University-San Marcos

Notropis oxyrhynchus

sharpnose shiner

Type Locality

Brazos River, at Wellborn Crossing, Brazos Co., TX (Hubbs and Bonham 1951).

Etymology/Derivation of Scientific Name

Derived from the Greek words meaning oxys (sharp) and rynchus (snout) (Hubbs and Bonham 1951).

Synonymy: Not applicable.

Characters

Maximum size: Up to 95 mm (3.74 in) SL (Durham 2007).

Coloration: Straw color with silvery sides.  Dorsal scales outlined with pigments.  Ventral white and without pigments.

Pharyngeal teeth count: 1,4-4,1 or 2,4-4,2 (Hubbs et al. 1991).

Counts: 9-12 anal fin soft rays (Hubbs et al. 1991).

Body shape: Laterally compressed body; broad body depth; pointed snout.

Mouth position: Terminal and oblique.

External morphology: Slightly falcate anal fin, dorsal fin begins well behind insertion of the pelvic fin (Hubbs et al. 1991).  Slightly decurved lateral line. 

Distribution (Native and Introduced)

U.S. distribution: Texas only.

Texas distribution: Endemic to Brazos River drainage.  Naturally found in the Red River drainage, when a tributary to the Brazos River was captured into the Red River drainage (Conner and Suttkus 1986, Cross et al. 1986).  Introduced in the Colorado River drainage (Gilbert 1980; Conner and Suttkus 1986). Warren et al. (2000) listed the following drainage units for distribution of Notropis oxyrhynchus in the state: Brazos River, Colorado River.

 [Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Jurgens (1954); Hubbs (1957); Gelwick and Li (2002); Li (2003); Winemiller et al. (2004); Zeug et al. 2005).]

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

Threatened (Hubbs et al. 1991, Warren et al. 2000).  Considered a candidate for listing by USFWS.  Mean relative abundance decreased from 22% (1939 - 1969) to 0.04% (1970 – 2006) in the lower Brazos River.  Populations likely extirpated in the middle Brazos River (Possum Kingdom Reservoir to Waco, TX) and appear stable in the upper Brazos River. 

Habitat Associations

Macrohabitat: Mainstem river; sometimes entering smaller tributaries. 

Mesohabitat: Moderate current velocities and depths.  Preference for 0.35 m/s when average current velocities <50 m/s; tend to avoid swifter currents and greater depths during periods of elevated discharge (Durham 2007).  Usually found in areas with sand substrate. In the upper Brazos River, Texas, species was most abundant at downstream sites where current velocity and depth were greatest; progressive decrease in abundance at upstream sites (Ostrand and Wilde 2002). Species has high thermal, low dissolved oxygen, and high salinity tolerances: mean critical thermal maxima = 39.2 ± 0.2°C (102-103° F); salinity tolerance = 15 ± 0.72‰; minimum dissolved oxygen tolerance (mean = 2.66 ± 0.12 mg/L) (Ostrand and Wilde 2001).

Biology

Spawning season: Developing ovaries in April, mature ovaries by mid-May through September with multiple peaks in gonadosomatic index, spent ovaries from July through October (Durham 2007).

Spawning habitat:  Open water.

Reproductive strategy: Likely open substrate pelgophil producing semi-buoyant eggs.  Batch spawner, producing multiple cohorts within a spawning season; population usually asynchronously egg production, but might also synchronously spawn during pulse flows (Durham 2007). 

Fecundity: Range from 80 to 2,470 vitellogenic oocytes per female; mean number ranged from 245 to 303 vitellogenic oocytes per female; maximum gonadosomatic index is 18% for females and 2% for males; maximum oocyte diameter is 1.1 mm (Durham 2007). 

Age at maturation: Likely age 1.

Migration: No substantial migratory movements by this species have been discovered (Durham 2007).

Growth and Population Structure: Mean growth rates for age-1 sharpnose shiners averaged 0.60 mm (0.02 in) TL/day over a 62 day period (Marks 1999).  Majority of population is age 1 (Durham 2007). 

Longevity: Up to age 2 (Marks 1999, Durham 2007).

Food habits: Generalist drift invertivore, consuming aquatic and terrestrial invertebrates (71% of diet) detritus, plant material and sand (Marks 1999, Moss and Mayes 1993; Marks et al. 2001). 

Phylogeny and morphologically similar fishes

Belongs to subgenus Notropis; closely related to Texas shiner (N. amabilis), emerald shiner (N. atherinoides), Rio Grande shiner (N. jemezanus), and silverband shiner (N. shumardi) (Bielawski and Gold 2001, Amemiya and Gold 1990, Coburn and Cavender 1992).

Host Records

No information at this time.

Commercial or Environmental Importance

No information at this time.

References

Amemiya, C.T. and J.R. Gold. 1990. Cytogenetic studies in North American minnows (Cyprinidae): XVII. Chromosomal NOR phenotypes of 12 species, with comments on cytosomatic relationships among 50 species. Hereditas 112:231-247.

Bielawski, J.P. and J.R. Gold. 2001. Phylogenetic Relationships of Cyprinid Fishes in Subgenus Notropis Inferred from Nucleotide Sequences of the Mitochondrially Encoded Cytochrome b Gene. Copeia, 2001(3):656-667.

Coburn, M.M. and T.M. Cavender 1992. Interrelationships of North American fishes, In: Systematics, historical ecology, and North American freshwater fishes. R. L. Mayden (ed.). Stanford University Press, Stanford, CA.

Conner, J.V. and R.D. Suttkus. 1986. Zoogeography of freshwater fishes of the western Gulf Slope of North America. Pages 413-456 in C.H. Hocutt and E.O. Wiley, editors. The zoogeography of North American freshwater fishes. Wiley, New York.

Cross, F.B., Mayden, R.L., and J.D. Stewart. 1986. Fishes in the Western Mississippi drainage. Pages 363-412 in C. H. Hocutt and E.O. Wiley, editors. The zoogeography of North American Freshwater Fishes. Wiley, New York

Durham, B.W. 2007.  Reproductive ecology, habitat associations, and populaton dynamics of two imperiled cyprinids in a great plains river.  Ph.D. Dissertation, Texas Tech University, Lubbock.

Fuller, P., L.G. Nico and J.D. Williams. 1999. Nonindigenous Fishes Introduced into Inland Waters of the United States. American Fisheries Society Special Publication 27, Bethesda, Maryland. 613 pp.

Gelwick, F.P., and R.Y. Li. 2002. Mesohabitat use and community structure of the Brazos River Fishes in the vicinity of the proposed Allens Creek Reservoir. Report to the Texas Water Development Board. 55 pp.

Gilbert, C.R. 1980. Notropis oxyrhynchus (Hubbs and Bonham), Sharpnose shiner. pp.291 in D.S. Lee, et al. Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Hubbs, C. 1957. Distributional patterns of Texas fresh-water fishes. The Southwestern Naturalist 2(2/3):89-104.

Hubbs, C.L., and K. Bonham. 1951. New Cyprinid fishes of the genus Notropis from Texas. The Texas Journal of Science 1:91-110.

Hubbs, C.L., 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.

Jurgens, K.C. 1954. Records for four Cyprinid fishes of the genera Notropis and Semotilus from Central Texas. 1954(2):155-156.

Li, R.Y. 2003. The influence of environmental factors on spatial and temporal variation of fish assemblages in the lower Brazos River, Texas. M.S. Thesis, Texas A&M University, College Station. 71 pp.

Marks, D.E. 1999. Life History Characteristics of the sharpnose shiner (Notropis oxyrhynchus) and the smalleye shiner (Notropis buccula) in the Brazos River, Texas. Ph.D. Dissertation, Texas Tech University, Lubbock.

Marks, D. E., G. R. Wilde, K. G. Ostrand and Philip J. Zwank. 2001. Foods of the smalleye shiner and sharpnose shiner in the upper Brazos River, Texas. Texas Journal of Science, 53(4):327-334.

Moss, R .E. and K. B. Mayes. 1993. Current status of Notropis buccula and Notropis oxyrhynchus in Texas. Final report, project number E-1-4. Resource Protection Division, Texas Parks and Wildlife Department, Austin.

Ostrand, K.G., and G.R. Wilde. 2001. Temperature, dissolved oxygen, and salinity tolerances of five prairie stream fishes and their role in explaining fish assemblage patterns. Trans. Amer. Fish. Soc. 130:742-749.

Ostrand, K.G., and G.R. Wilde. 2002. Seasonal and spatial variation in a prairie stream-fish assemblage. Ecology of Freshwater Fishes 11:137-149.

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.

Winemiller, K.O., F.P. Gelwick, T.H. Bonner, S. Zeug, and C. Williams. 2004. Response of oxbow lake biota to hydrologic exchanges with the Brazos River channel. Final Project Report to the Texas Water Development Board. 59 pp.

Zeug, S.C., K.O. Winemiller, and S. Toner. 2005. Response of Brazos River oxbow fish assemblages to patterns of hydrologic connectivity and environmental variability. Trans. Amer. Fish. Soc. 134:1389-1399.