Semotilus atromaculatus

creek chub



Type Locality

Wallkill River, New York (Mitchill 1818).


Etymology/Derivation of Scientific Name

Semotilus, from the Greek word sema, “a banner,” (i.e. dorsal fin); the second part of the word was used elsewhere by its author (Rafinesque) to mean “spotted;” atromaculatus, Latin, “black spot.”



Cyprinus atromaculatus Mitchill 1818:324.

Semotilus corporalis Hay 1881:512, 1883:72.

Semoltilus atromaculatus Hildebrand and Towers 1928:119; Cook 1959:100.



Maximum size: 330 mm TL (Copes 1978). From Texas, largest specimen found in research museums is 97 mm SL (Edwards 1997).


Coloration: Dark gray to brown on back, cream colored sides interrupted by conspicuous dark lateral stripe; dark spot is present at the anterior base of dorsal fin. Peritonium silvery. Nuptial males develop a rosy band along the side and red around the dark dorsal fin spot (Etnier and Starnes 1993).


Counts: Pharyngeal teeth 2,5-5,2 or 2,5-4,2;  fewer than 10 soft rays on dorsal fin (Hubbs et al. 1991); lateral line scales 42-70; predorsal scale rows 30-33; anal fin rays 8 (7-9); pectoral fin rays 13-18; gill rakers 7-11

(Etnier and Starnes 1993).


Body shape: Robust, almost cylindrical, slightly compressed posteriorly (Becker 1983).


Mouth position: Mouth large and only moderately oblique (Hubbs et al 1991).


External morphology: Lateral line usually not decurved, either straight or with broad arch; premaxillaries protractile; upper lip separated from skin of snout by a deep groove continuous across the midline; cartilaginous ridge of lower jaw hardly evident and not separated by a definite groove from the lower lip; 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). A row of 3 (3-9) large, hooked tubercles extends on each side of the head from just in front of the nostrils to just behind the upper portion of the eye. Pectoral fin rays 2-7 bear large uniserial tubercles on their dorsal surfaces, and tubercles may develop on the upper edge of the caudal fin base, dorsal fin rays, and posterior anal fin rays. Body scales posterior to the anal origin have a marginal row of 6-8 tubercles that are best developed on mid sides. Tiny tubercles also occur on cheeks and opercles (Etnier and Starnes 1993).


Distribution (Native and Introduced)

U.S. distribution: Found throughout eastern United States (Hubbs et al 1991).


Texas distribution: It is limited to the smaller streams of eastern Texas and to coastal waters of Brazos Basin (Hubbs et al 1991). Warren (2000) listed the species as occuring in the following drainage units: Red River unit (from the mouth upstream to and including the Kiamichi River), Sabine Lake unit (including minor coastal drainages west to Galveston Bay), Galveston Bay unit (including minor coastal drainages west to mouth of Brazos River), Brazos River unit; species distribution in the Colorado River unit was questionable.


Abundance/Conservation status (Federal, State, NGO)

Populations in southern United States are considered currently stable (Warren et al., 2000). Nowhere is the creek chub reported in peril (Boschung and Mayden 2004).


Habitat Associations

Macrohabitat: Abundant in small streams and clear creeks and brooks; occasionally in shallows of small clear lakes (Lee and Platania 1980).


Mesohabitat: Commonly inhabiting headwater creeks often having few other fishes; these streams often intermittent, with the creek chub inhabiting the pools containing cover for escapes from other predators, including birds (Fraser and Gilliam 1986; Edwards 1997). Commonly associated with Campostoma anomalum in small creek habitats. Species apparently avoids larger streams having continuous strong flows and a variety of competing fishes (Edwards 1997). Encountered over substrates of gravel (23% frequency), sand (22%), silt (15%), rubble (11%), mud (11%), boulders (6%), clay (5%), bedrock (4%), and detritus (3%); occurred in clear to dark brown waters, preferring silt-free to slightly turbid waters, although taken in numerous locales with turbid water; tolerant of considerable pollution (Becker 1983).



Spawning season: Occurs in the spring as water temperatures rise above 14-18 degrees C (Moshenko and Gee 1973; Ross 1977). In Texas, based on length and collection dates of specimens in research museums, Edwards (1997) suggested breeding activities begin in June and continue through November.


Spawning habitat: Brood-hiding lithophils; rock and gravel nesters that do not guard their eggs (Simon 1999; Balon 1975). Nests usually in moderately flowing water, typically, but not always, above a riffle; spawning occurs in pits built by the male (Miller 1964).


Reproductive strategy: Miller (1964) summarized observations by Reighard (1910) as follows: male excavates shallow pit and creates a small pile by picking up stones in mouth and depositing them on the upstream edge of the pit; excavation extended farther downstream as the male gradually fills in the anterior portions of the pit by continued digging and stone carrying, forming a ridge of gravel one to several feet long and roughly a foot wide covering a previously excavated trench and a shallow pit downstream to the ridge; male defends pit and at times parts of the ridge against male predators; spawning occurs when female enters nest, approaching the male, which clasps her between pectoral fin and body; when clasp, egg release, and fertilization completed, female floats upwards and swims away; Miller (1964) notes that fighting is rare and that the parallel swim is a ritual combat between a male residing in the nest and an intruding male; male occasionally uses pit from stoneroller minnows after driving them away; may also use nest inhabited by one or more common shiners, digging and carrying stones unopposed.


Fecundity: Number of mature ova is closely related to female body size and varies from 1146 to 7539 (Moshenko and Gee 1973; Schemske 1974). A 78 mm SL female produces about 1100 eggs, each 1.4 to 1.5 mm in diameter at maturity, whereas a 97 mm SL female may produce twice as many eggs, each 1.6 to 1.7 mm in diameter; larger creek chubs, those about 155 mm long, may produce 7500 eggs per year (Boschung and Mayden 2004).


Age at maturation: Production of mature ova began in 2nd year females that had reached 62.8 mm SL; accordingly all age I females greater than 62.8 mm SL contained either secondary or mature ova (Schemske 1974). Copes (1978) noted that maturity occurs at age III in males, and in some age I females.


Migration: Over a one to three month period, marked fish moved an average of 0.78 km in the fall and 0.24-0.42 km in the spring and summer (Moshenko and Gee 1973). In some streams, species may undergo upstream migrations prior to spawning (Hankinson 1920; Becker 1983).


Growth and population structure: Populations comprised mainly of age class 0-3 individuals. In Illinois, at the end of first year of life, species averaged 50 mm SL; average SL were 78 mm, 110 mm, and 133 mm for years 2-4 (Lewis and Elder 1953; Gunning and Lewis 1956). Males grow more rapidly than females (Copes 1978).


Longevity: 3 years (Gunning and Lewis 1956; Lewis and Elder 1953; Edwards 1997); few live longer than age VI (Copes 1978). Boschung and Mayden (2004) and Etnier and Starnes (1993) list an extended life span of 6 years.


Food habits: Invertivore/carnivore; young feed on planktonic organisms; adults feed on insect larvae such as beetles, mayflies, caddisflies, and chironomids; large males will also eat crayfish and small fishes (Goldstein and Simon 1999). Classified as sight feeders because the taste lobes of the brain are not enlarged (Carlander 1969).


Phylogeny and morphologically similar fishes

In Semotilus, the mouth is large and terminal versus small and inferior, characters that readily distinguish them from Campostoma and Rhinichthys (Boschung and Mayden 2004).


Host Records:

Dactylgyrus atromaculatus, Dactylgyrus attenuatus, Dactylgyrus lineatus, Dactylgyrus microphallus, Dactylgyrus tenax (Mizzle and McDougal 1970). Protozoa, Trematoda, Cestoda, Nematoda, Acanthocephala, Mollusca, Crustacea (Hoffman 1967). Semotilis atromaculatus is the host to the glochidia of the clams Anodonta imbecilis and Strophitus undulates; hence it is partially responsible for the success of these mollusks (Hart and Fuller 1974).


Commercial or Environmental Importance

Creek chub makes excellent bait as it is very hardy, holding up well in the bucket or on a hook, and tolerating great exposure to sudden changes in water temperature; well suited for mass production in artificial ponds (Becker 1983; Scott and Crossman 1973; Dobie et al.1956).


[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Lake Travis and Lake Granite Shoals (lower Colorado River; Jurgens 1954); Hubbs (1957); Big Sandy Creek (Evans and Noble 1979).]



Balon, E.K. 1975. Reproductive guilds of fishes: a proposal and definition. Journal of the Fisheries Research Board of Canada 32:821-864.

Becker, G. C. 1983. Fishes of Wisconsin. The University of Wisconsin Press, Madison, 1052 pp.

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

Carlander, Kenneth D. 1969. Hankbook of Freshwater Fishery Biology. The Iowa State University Press, Ames. Vol. 1:752

Cook, F.A. 1959. Freshwater fishes in Mississippi. Mississippi Game and Fish Commision, Jackson.

Copes, F. 1978. Ecology of the creek chub Semotilus atromaculatus (Mitchill) in northern waters. Univ. Wis., Stevens Point, Mus. Nat. Hist. Fauna and Flora Wis. Rep. No. 12:1-21.

Dobie, J., O.L. Meehean, S.F. Snieszko, and G.N. Washburn. 1956. Raising Bait Fishes. U.S. Fish Wildlife Serv. Circ. 35:123 p.

Edwards, R. J. 1997. Ecological profiles for selected stream-dwelling Texas freshwater fishes I. Texas Water Development Board. March 31, 1997. TWBD 95-483-107. 89 pp.

Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press, Knoxville. 681 pp.

Evans, J.W., and R.L. Noble. 1979. The longitudinal distribution of fishes in an east Texas stream. American Midland Naturalist 101(2):333-343.

Fraser, D.F., and J.F. Gilliam. 1986. Habitat selection under a tradeoff of foraging rate and mortality rate: a priori predictions for creek chubs. Amer. Fish. Soc. Annual Mtg. 116:65.

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: Simon, T. P. (ed.). Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press. Boca Raton, Florida. 671 pp.

Gunning, G.E., and W.M. Lewis. 1956. Age and growth of two important bait species in a cold-water stream in southern Illinois. American Midland Naturalist 55(1):118-120.

Hankinson, T.L. 1920. Notes of life histories of Illinois fish. Trans. Ill. St. Acad. Sci., Springfield 12(1919):132-150.

Hart, C.W., Jr., and S.L.H. Fuller. 1974. Pollution ecology of freshwater invertebrates. Academic Press, N.Y. 389 pp.

Hay, O.P. 1881. On a collection of fishes from eastern Mississippi. Proc. U.S. Nat. Mus. 3:488-515.

Hay, O.P. 1883. On a collection of fishes from the lower Mississippi Valley. Bull. U.S. Fish Comm. 2:57-75.

Hildebrand, S.F. and I.L. Towers. 1928. Annotated list of fishes collected in the vicinity of Greenwood Mississippi, with descriptions of three new species. Bull. U.S. Bur. Fish. 43(2)105-136

Hoffman, Glenn L. 1967. Parasites of North American Freshwater Fishes. University of California Press, Berkeley, 486 pp.

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. Garret. 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 of four cyprinid fishes of the genera Notropis and Semotilus from central Texas. Copeia 1954(2):155-156.

Lee, D.S. and Platania S.P. 1980. Semotilus atromaculatus (Mitchill), Creek Chub. pp. 361 in D.S. Lee et al. Atlas of North American Freshwater Fishes. N.C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Lewis, W.M., and D. Elder. 1953. The fish population of the headwaters of a spotted bass stream in southern Illinois. Trans. Amer. Fish. Soc. 82:193-202.

Mettee, M.F., P.E. Neil, and J.M. Pierson. 1996. Fishes of Alabama and the Mobile Basin. Oxmoor House, Birmingham, Alabama.

Miller, R. J. 1964. Behavior and Ecology of Some North American Cyprinid Fishes. American Midland Naturalist, 72(2):313-357.

Mitchell, S.L. 1815. The fishes of New York described and arranged. Trans. Literary Phil. Soc. New York 1:355-492.

Mizelle, J.D. and H.D. McDougal. 1970 Studies on Monogenetic Trematodes. XLV. The genus Dactylogyrus in North America. Key to Species, Host Parasite and Parasite host lists, Localities, emendations, and description of D. Kritskyi sp.n. Amer. Midl. Nat. 84(2):444-462.

Moshenko, R.W., and J.H. Gee. 1973. Diet, time and place of spawning, and environments occupied by creek chub (Semotilus atromaculatus) in the Mink River, Manitoba. J. Fish. Res. Bd. Can. 30(3):357-362.

Reighard, J. 1910. Methods of studying the habits of fishes, with an account of the breeding habits of the horned dace. Bull. U. S. Bur. Fish. 28(2):1111-1136.

Ross, M.R. 1977. Function of creek chub (Semotilus atromaculatus) nest-building. Ohio J. Sci. 77(1):36-37.

Schemske, D. W. 1974. Age, Length, and Fecundity of the Creek Chub, Semotilius atromaculatus (Mitchill), in Central Illinois. American Midland Naturalist, 92(2):505-509.

Scott, W.B., and E.J. Crossman. 1973. Freshwater Fishes of Canada. Fisheries Research Board of Canada, Ottawa. 966 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.

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.