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Semotilus atromaculatus

What do they look like?

Adult creek chubs are slender with a large dark spot at the front of their dorsal fin and a smaller dark spot at the base of their tail fin. Their total body length ranges from 12 to 18 cm (30 cm maximum). Their head is broad with a short snout and a large mouth with a small whisker (barbel) in the groove above their upper lip. Their backs are dark olive with a dark strip in the middle, their bellies are white, their sides are silvery, and their fins are yellow to light olive. Spawning males develop round nodules on their head, snout, fins, sides, and tails, are a bright apple-green above and rose-red below, and are larger in size than females. ("Methods of studying the habits of fishes, with an account of breeding habits of the horned dace", 1908; Copes, 1978; Michael, 1977; Moshenko, 1972; Pflieger, 1997; Simon, 2011)

  • Sexual Dimorphism
  • male larger
  • sexes colored or patterned differently
  • male more colorful
  • Range length
    12 to 30 cm
    4.72 to 11.81 in

Where do they live?

Creek chubs (Semotilus atromaculatus) are widely found in eastern North America. Their range extends from Newfoundland through southern Canada to the Rocky Mountains, and as far south as Florida. (Copes, 1978; Moshenko, 1972; Pflieger, 1997; Simon, 2011)

What kind of habitat do they need?

Creek chubs need flowing water for spawning and are often found in small headwater creeks, small streams, and agricultural ditches over gravel and sand substrates. They do not do well in streams with strong continuous flow, as they are not able to compete against larger fish species. They are able to tolerate some cloudiness in their water as long as they have enough gravel available for spawning. (Copes, 1978; Moshenko, 1972; Nagrodski, et al., 2013; Pflieger, 1997; Simon, 2011; Stauffer, 2007)

  • These animals are found in the following types of habitat
  • freshwater
  • Aquatic Biomes
  • rivers and streams

How do they grow?

Once the eggs of creek chubs are fertilized, they develop inside the nest without any parental care. Within six days after fertilization, the eggs begin to hatch. Newly hatched larvae have slightly downward curved heads and are considered to be in the prolarvae stage as they absorb their yolk. This stage ends and the postlarvae stage begins when the yolk has been absorbed and all of their fins except the pelvic fin are visible. The postlarvae stage lasts until the young fish starts to look like adults. The entire larval stage lasts 18 to 27 days. ("Methods of studying the habits of fishes, with an account of breeding habits of the horned dace", 1908; Buynak and Mohr, 1979; Copes, 1978; Dinsmore, 1962; Moshenko, 1972; Pflieger, 1997)

How do they reproduce?

Creek chubs are promiscuous, with multiple females visiting and laying eggs at a few different nests and males mating with several different females. Males build pit nests (one male per nest) that are about 5.7 cm deep on the gravel bottom, near the lower end of the pool (where the current is quicker). Using their mouth, males dig a small trench and pile small stones upstream forming a ridge about 30 cm wide and 550 cm long. The male guards the nest and drives off other minnow species and smaller creek chubs. If they are challenged by a male of similar size, the two may perform a ritual known as 'deferred combat'. The resident male arranges himself alongside the intruder and the two fish swim upstream for varying distances. At the end, the two males settle to the bottom and bring their heads together, gently, and separate, with the owner returning to the nest. In addition to not being overly aggressive, the condition and location of their nest is important for male breeding success. While males construct nests, females wait nearby. At this time, they approach the male and his nest but usually flee once the male sees them. This behavior continues until a female does not feel intimidated and enters the nest. When a female enters the nest to spawn, the male takes up a position at the bottom of the nest near the lower end of the gravel ridge and waits for the female to be above him. The female can still be startled and flee, if this happens, the male may follow and bite her. When a female does not flee, they embrace for a few seconds while the female deposits her eggs. The female leaves the nest after depositing her eggs and another female may enter the nest and mate with the male. Once the male is done mating, he abandons his nest. ("Methods of studying the habits of fishes, with an account of breeding habits of the horned dace", 1908; Copes, 1978; Moshenko and Gee, 1973; Moshenko, 1972; Pflieger, 1997; Stauffer, 2007)

Male creek chubs grow at a faster rate than females. Most males are ready to breed when they are 3 years old. Once they are ready to breed, males develop bumps and change color, making them look different than females. Females are also ready to breed near the age of 3 years, but some females reach maturity after one year. Longer females produce more eggs. Their eggs are large and round (0.15 to 0.2 cm in diameter) and have a yellowish color. Mating occurs for about two weeks, from mid-spring to early summer in waters with temperatures above 14° C. During spawning, males and females are found in fast shallow channels, with more males than females. Females can lay between 500 to 4,000 eggs (depending on their age). If the female is large enough, she can go to another male's nest and lay additional eggs. ("Methods of studying the habits of fishes, with an account of breeding habits of the horned dace", 1908; Buynak and Mohr, 1979; Moshenko and Gee, 1973; Moshenko, 1972; Stauffer, 2007)

  • How often does reproduction occur?
    Creek chubs breed once a year.
  • Breeding season
    Mating occurs for about two weeks, from mid-spring to early summer, in waters with temperatures above 14° C.
  • Range number of offspring
    500 to 4000
  • Average time to hatching
    6 days
  • Range age at sexual or reproductive maturity (female)
    1 to 4 years
  • Range age at sexual or reproductive maturity (male)
    2 to 4 years

Neither the male nor the female offers any parental care. ("Methods of studying the habits of fishes, with an account of breeding habits of the horned dace", 1908; Copes, 1978)

  • Parental Investment
  • no parental involvement
  • pre-fertilization
    • provisioning

How long do they live?

Creek chubs live 4 to 5 years, with a maximum lifespan of 8 years. (Copes, 1978; Moshenko, 1972; Pflieger, 1997)

  • Typical lifespan
    Status: wild
    3 to 8 years
  • Average lifespan
    Status: wild
    5 years

How do they behave?

Creek chubs are active and feed during the day after the water temperature has increased a few degrees. Larvae, however, are active throughout the day and are generally found in the shallow runs of creeks, streams, or agricultural ditches. They are often found with larvae of other fish species such as longnose daces and common shiners. Larvae seek shelter under plants and stay away from deep areas to avoid being eaten. Juvenile creek chubs school with other minnow species such as pearl daces and brassy minnows. They are found on the edge of pools and deeper runs. Creek chubs that are larger than 1.8 cm generally do not school and occupy sheltered areas in deeper pools. They are active and instantly go towards any small object falling into the water. The majority of their time is spent near or underneath cover, only moving short distances from one cover area to another. Creek chubs winter in deep pools and runs. ("Methods of studying the habits of fishes, with an account of breeding habits of the horned dace", 1908; Michael, 1977; Moshenko, 1972; Pflieger, 1997)

Home Range

Creek chubs may move quite a bit both upstream and downstream to avoid predators and to find resources. Although they are very mobile, their average maximum range is 130 to 195 m but some travel up to 600 m. (Belica and Rahel, 2008)

How do they communicate with each other?

Creek chubs mostly communicate using their vision. During the spawning season, males interact with other males and intruders by assessing their size, swimming patterns, and sometimes by physical contact. Other related fish species may release a chemical alarm when they are injured, which may alert creek chubs of possible danger. ("Methods of studying the habits of fishes, with an account of breeding habits of the horned dace", 1908; Copes, 1978; Pflieger, 1997)

What do they eat?

Creek chubs are carnivores with a very adaptable diet. They also eat a small amount of plant matter, but this is mostly associated with eating their prey. In their first few months of life, they eat aquatic insect larvae. As they age, they eat adult terrestrial insects. When they get even bigger, they eat smaller fish, including other creek chubs, amphibians, crayfish, and mollusks. (Copes, 1978; Michael, 1977; Moshenko and Gee, 1973; Moshenko, 1972; Pflieger, 1997)

  • Animal Foods
  • amphibians
  • fish
  • insects
  • mollusks
  • Plant Foods
  • leaves
  • roots and tubers

What eats them and how do they avoid being eaten?

Creek chubs are preyed on by larger fish such as brown trout, northern pike, small mouth bass, and larger creek chubs. (Copes, 1978; Moshenko, 1972)

What roles do they have in the ecosystem?

Creek chubs are often found in headwater creeks, streams, and in degraded areas such as agricultural ditches, where they are found in great abundance. They are the top predator in most of these habitats. (Copes, 1978; Michael, 1977; Moshenko and Gee, 1973)

Commensal or parasitic species (or larger taxonomic groups) that use this species as a host
  • Saproloegnia

Do they cause problems?

Creek chubs have become invasive in western states such as Wyoming. They compete, and in some cases outcompete native fish species such as roundtail chubs in Colorado. (Quist, et al., 2006)

How do they interact with us?

Creek chubs are often sold and used as bait. They can also indicate the quality of a given stream. There tend to be larger populations of creek chubs in degraded areas and a lower diversity of other fish species. (Jordan, et al., 2013; Lau, et al., 2006; Pflieger, 1997)

  • Ways that people benefit from these animals:
  • research and education

Are they endangered?

Creek chubs are abundant throughout their geographic range. (Copes, 1978; Moshenko and Gee, 1973; Moshenko, 1972; Pflieger, 1997; Simon, 2011)


Zane Anderson (author), Indiana University-Purdue University Fort Wayne, Mark Jordan (editor), Indiana University-Purdue University Fort Wayne, Leila Siciliano Martina (editor), Animal Diversity Web Staff.


U.S. Bureaus of Fisheries. Methods of studying the habits of fishes, with an account of breeding habits of the horned dace. 28. Washington, D.C.: 1113-1136. 1908.

Belica, L., F. Rahel. 2008. Movements of creek chubs, Semotilus atromaculatus, among habitat patches in a plains stream. Ecology of Freshwater Fish, 17.2: 258-272.

Buynak, G., H. Mohr. 1979. Larval development of creek chub and fallfish from two Susquehanna River tributaries. The Progressive Fish-Culturist, 41/3: 124-129.

Copes, F. 1978. Ecology of the creek chub. Reports on the Fauna and Flora of Wisconsin, 12: 21.

Dinsmore, J. 1962. Life history of the creek chub with emphasis on growth. Proceedings of the Iowa Academy of Sciences, 69: 296-301.

Jordan, M., P. Deepal, S. Kathryn, R. Gillespie. 2013. The relative roles of contemporary and ancient process in shaping genetic variation of a generalist fish in catchment dominated by agriculture. Freshwater Biology, 58: 1660-1671.

Lau, J., T. Lauer, M. Weinman. 2006. Impacts of channelization on stream habitats and associated fish assemblages in east central Indiana. American Midland Naturalist, 156/2: 319-330.

Magnan, P., G. FitzGerald. 1984. Ontogenetic changes in diet activity, food habits and spatial distribution of juvenile and adult creek chub, Semotilus atromaculatus. Environmental Biology of Fishes, 11.4: 301-307.

Michael, R. 1977. Aggression as a social mechanism in the creek chub (Semotilus atromaculatus). Copeia, 1977: 393-397.

Moshenko, R. 1972. Ecology of the northern creek chub, Semotilus atromaculatus (Mitchill) in the Mink River, Manitoba. Winnipeg, Manitoba: The University of Manitoba.

Moshenko, R., J. Gee. 1973. Diet, time and place of spawning, and environments occupied by creek chub (Semotilus atromaculatus) in the Mink River, Manitoba. Journal of the Fisheries Board of Canada, 30.3: 357-362.

Nagrodski, A., C. Suski, S. Cooke. 2013. Health, condition, and survival of creek chub (Semotilus atromaculatus) across a gradient of stream habitat quality following an experimental cortisol challenge. Hydrobiologia, 702.1: 283-293.

Pflieger, W. 1997. The Fishes of Missouri. Jefferson City, MO: Missouri Department of Conservation.

Quist, M., M. Bower, W. Hubert. 2006. Summer food habits and trophic overlap of round tail chub and creek cub in Muddy Creek, Wyoming. The Southwestern Naturalist, 51/1: 22-27.

Simon, T. 2011. Fishes of Indiana. Bloomington, IN: Indiana University Press.

Stauffer, J. 2007. Fishes of West Virginia. The Pennsylvania Sate University: Academy of Natural Sciences.

University of Michigan Museum of ZoologyNational Science Foundation

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Anderson, Z. 2014. "Semotilus atromaculatus" (On-line), Animal Diversity Web. Accessed May 21, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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