Picture by Chad Thomas, Texas State University-San Marcos



Notropis chalybaeus

ironcolor shiner



Type Locality

Tributary of the Schuylkill River, near Conshohocken, Montgomery Co., Pennsylvania (Cope 1869).


Etymology/Derivation of Scientific Name

Notropis: keeled back; chalybaeus: iron colored, in reference to the lateral band (Ross 2001).



Hybopsis chalybaeus Cope 1869:383.

Notropis chalybaeus abbotti Swift 1970; Gilbert 1978.



Maximum size:  53 mm (2.09 in) SL (Ross 2001).


Coloration: Caudal spot, if present, attached to midlateral stripe; midlateral stripe distinct; paired dots along lateral line (Hubbs et al 1991). The back is olive-yellow to dusty brown, with scales pigmented on their margins, producing cross-hatched pattern. Breeding males develop an orange to rosy hue over the entire body, with the greatest intensity over dorsal and caudal fins, especially the ventral side of the caudal peduncle; females and nonbreeding males may exhibit some coloration, but more subdued than in breeding males. Inside of mouth, especially anterior portion of the roof, distinctly sprinkled with black pigment (Ross 2001).


Counts: Pharyngeal teeth 2,4-4,2 or 1, 4-4,1; usually 8 anal fin soft rays (Hubbs et al. 1991); 32-34 (31-37) lateral line scales, 13-15 pectoral soft fin rays and 8 pelvic soft fin rays (Ross 2001). A disjunct population in the San Marcos River (Hays Co.), Texas, averages one more pectoral ray (9 vs. 8) and one more vertebra (36 vs. 35) compared to east Texas populations (Swift 1977).


Body shape: Deep, compressed body; slender caudal peduncle (Swift 1977).


Mouth position: Terminal and oblique (Hubbs et al 1991).


Morphology: Large eye, longer than snout (Page and Burr 1991). Dorsal fin more triangular, last fin ray less than one-half length of the longest; interradial membranes of dorsal fin without melanophores, except along rays; first obvious dorsal fin ray a thin splint, closely attached to the following well developed but unbranched ray; lower lip thin, without fleshy lobes; premaxillaries protractile; upper lip separated from skin of snout by a deep groove continuous across the midline; distance from origin of anal fin to end of caudal peduncle contained two and one-half or fewer times in distance from tip of snout to origin of anal fin (Hubbs et al 1991); lateral line moderately decurved anteriorly (Swift 1977); belly scaled; breast naked or partially scaled (Ross 2001). Nuptial males develop tubercles on head (primarily tip of snout), around eyes, lips, and lower jaw; weak tubercles form along distal margin of dorsolateral scales anterior to dorsal fin; pectoral rays 2-7 develop tubercles along dorsal surface; females may develop weak tubercles on lower jaw and pectoral rays; pelvic fins of tuberculate males extend past vent, nearly reaching anal fin base (Ross 2001).


Internal morphology: Intestinal canal short, forming a simple S-shaped loop (Hubbs et al. 1991).


Distribution (Native and Introduced)

U.S. distribution: Found in coastal streams from New York to Texas, and in the southern Great Lakes through parts of the Mississippi River to the Gulf of Mexico (Hubbs et al 1991). Common along lower Gulf Coast, much more sporadic toward peripheries of range (Swift 1980).


Texas distribution: Found only in northeastern streams from the Sabine to the Red River with the exception of an isolated population found in the San Marcos River headwaters (Hubbs et al 1991). Warren et al. (2000) lists this species as inhabiting the following drainage units: Red River (from the mouth upstream to and including the Kiamichi River), Sabine Lake (including minor coastal drainages west to Galveston Bay), San Antonio Bay (including minor coastal drainages west of mouth of Colorado River to mouth of Nueces River).


[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Hubbs (1957); San Marcos River (BIO-WEST, Inc. 2003).]


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

In Texas, listed as a species of special concern (Hubbs et al 1991). Populations in the southern United States are vulnerable (Warren et al. 2000).


Habitat Associations

Macrohabitat: Habitat varies somewhat throughout range (Marshall 1947). Commonly inhabits small to medium sized streams that drain pine woodlands (McClane 1955; Hellier 1967; Robison 1977).


Mesohabitat: Found primarily in acid, tannin-stained, non-turbid sluggish Coastal Plain streams and rivers of low to moderate gradient (Robison 1977). Occurs in aggregation, often at the upstream ends of pools, with a moderate to sluggish current, and sand, mud, silt, or detritus substrata (Robison 1977; Ross 2001); usually associated with aquatic vegetation (Hellier 1967; Robison 1977); these pools important in breeding (Becker 1983). Fishes usually in midwater or near surface (Swift 1980; Marshall 1947). Exhibits tendency to move into quiet water whenever possible (Becker 1983). In the San Marcos River (Hays Co.), Texas, a disjunct population of this species is restricted to a short portion of the river, which is clear, spring-fed and has an abundance of aquatic vegetation (Swift 1977).



Spawning season: May be quite protracted based on Florida studies, extending from March-April to September-October (Marshall 1947; McClane 1955; Hellier 1967).


Spawning location: Lithopelagophils; rock and gravel spawners with pelagic free embryos (Simon 1999). Marshall (1947) noted disperse distribution of eggs, which sank to bottom, adhering to sand particles and similar bottom materials, in sluggish, sandy pools.

Reproductive strategy: Males in spawning condition pursue females until a female ceases her retreat. The pair will swim vent to vent then separate during which the eggs are released and fertilized (Marshall 1947).


Fecundity: A gravid female from Scott County, Missouri, held 246 mature, orange-yellow eggs 0.7-0.8 mm (0.028-0.031 in) diameter, and an equal number of immature yellow-white eggs 0.4-0.5 mm (0.015-0.019 in) diameter; ovaries were 12% of the body weight (Becker 1983). Marshall (1947) stripped approximately 50 fertilized eggs from a female; these hatching in about 54 hours at an average temperature of 16.6°C (62°F).


Age at maturation: In Wisconsin, may occur at age 1 (Becker 1983).


Migration:  NA


Growth: Wisconsin specimens aged by scale analysis: In the Fox River collection, young-of-year 24-29 mm (0.94-1.14 in)TL, and age-I  33-48 (1.30-1.89 in) mm TL; calculated length for the first annulus was 29.0 mm (1.14 in).  From Blake Creek, age-I  40.5 and 43 mm TL (1.60 and 1.70 in); an estimated 28.5 mm (1.12 in) at the first annulus (Becker 1983). In Arkansas, lengths ranged from 15.7-20.0 mm (0.62-0.79 in) SL in a collection of 18 young-of-the-year (Robison and Buchanan 1988). Females are reported to average slightly larger than males (Marshall 1947). Larval development described by Marshall (1947) and Fuiman et al. (1983).


Longevity:  May reach at least 2-years-old; this based on collection of a 2-year-old, female from a canal in Grant City, Missouri (Becker 1983).


Food habits: Invertivore (Goldstein and Simon 1999). Sight-feeder (Marshall 1947). Major food items include small crustaceans (amphipods, cladocerans, and ostracods), aquatic insects (caddisflies, flies/midges, mayflies, water boatmen), and terrestrial insects (ants), and filamentous algae (Marshall 1947; McClane 1955; Swift et al. 1977; Ross 2001).


Phylogeny and morphologically similar fishes

Member of the Notropis texanus species group (Swift 1970; Coburn 1982; Mayden 1989). The dark lateral band could result in the ironcolor shiner being confused with several minnows, including the weed shiner (N. texanus) and pugnose minnow (Opsopoeodus emiliae), which are similarly marked. Ironcolor shiners have distinctive black pigment inside the mouth, higher anal ray count (8 versus 7) and a more intense black lateral band (Ross 2001; Boschung and Mayden 2004).


Host Records

No information at this time.


Commercial or Environmental Importance

This species is rare, endangered, and extirpated in several states on the periphery of its range (Boschung and Mayden 2004).



BIO-WEST, Inc. 2003. Comprehensive and critical period monitoring program to evaluate the effects of variable flow on biological resources in the San Marcos Springs/River Aquatic Ecosystem. Final 2002 Annual Report. Edwards Aquifer Authority. 74 pp.

Boschung, H.T., Jr., and R.L. Mayden. 2004. Fishes of Alabama. Smithsonian Books, Washington. 736 pp.

Coburn, M.M. 1982. Anatomy and relationships of Notropis atherinoides. Ph.D. dissertation. Ohio State University, Columbus. 405 pp.

Cope, E. D. 1869. Synopsis of the Cyprinidae of Pennsylvania. Trans. Amer. Phil. Soc. new ser., pt. 3, 13:350-339.

Fuiman, L.A., J.V. Conner, B.F. Lathrop, G.L. Buynak, D.E. Snyder, and J.J. Loos. 1983. State of the art of identification for cyprinid fish larvae from eastern North America. Transactions of the American Fisheries Society 112:319-332.

Gilbert, C.R. 1978. Type catalog of the North American cyprinid fish genus Notropis. Bull. Fla. State Mus. 23(1):1-104.

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.

Hellier, T. R., Jr. 1967. The fishes of the Santa Fe River system. Bull. Fla. State Mus. Biol. Ser. 2(1):1-46.

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

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, Supplement 43(4):1-56.


Marshall, N. 1947. Studies on the life history and ecology of Notropis chalybaeus (Cope). Quart. J. Fla./Acad. Sci. 9(3/4):163-188.


Mayden, R.L. 1989. Phylogenetic studies of North American minnows, with emphasis on genus Cyprinella (Teleostei: Cypriniformes). Misc. Publ. Univ. Kansas Mus. Nat. Hist. 80:1-189.

McClane, W. M. 1955. The fishes of the St. John River system. Ph.D. diss., Univ. Florida, Gainesville.


Page, L.M., and B.M. Burr.  1991.  A field guide to freshwater fishes of North America north of Mexico.  Houghton Mifflin Company, Boston, Massachusetts. 432 pp.

Robison, H. W. 1977. Distribution, habitat notes and status of the ironcolor shiner, Notropis chalybaeus Cope in Arkansas. Proc. Ark. Acad. Sci. 31:92-94.

Robison, H.W., and T.M. Buchanan. 1988. Fishes of Arkansas. The University of Arkanasas Press, Fayetteville. 536 pp.

Ross, S. T. 2001. The Inland Fishes of Mississippi. University Press of Mississippi, Jackson, 624 pp.

Simon, T. P. 1999. Assessment of Balon’s reproductive guilds with application to Midwestern North American Freshwater Fishes, pp. 97-121. In: Simon, T.L. (ed.). Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press. Boca Raton, Florida. 671 pp.

Swift, C.C. 1970. A review of the eastern North American cyprinid fishes of the Notropis texanus species group (subgenus Hydrophlox, Alburnops), with a definition of the subgenus Hydrophlox, and materials for a revision of the subgenus Alburnops. Ph.D. dissertation. Florida State University, Tallahassee. 518 pp.

Swift, C.C. 1980. Notropis chalybaeus (Cope), Ironcolor shiner. pp. 250 in D.S. Lee et al. Atlas of North American Freshwater Fishes. N.C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Swift, C.C., R.W. Yerger, and P.R. Parrish. 1977. Distribution and natural history of the fresh and brackish water fishes of the Ochlockonee River, Florida and Georgia. Bull. Tall Timbers Res. Sta. 20:1-111.

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, Conservation. 25(10):7-29.