Semotilus atromaculatusChub(Also: Creek chub; Horned dace)

Ge­o­graphic Range

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

Habi­tat

Creek chubs re­quire 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 thrive in streams with strong con­tin­u­ous flow, as they are not able to com­pete suc­cess­fully against larger fish species. They are able to tol­er­ate mod­er­ately high tur­bid­ity as long as there is a suf­fi­cient amount of gravel sub­strate for spawn­ing. (Copes, 1978; Moshenko, 1972; Na­grod­ski, et al., 2013; Pflieger, 1997; Simon, 2011; Stauf­fer, 2007)

  • Aquatic Biomes
  • rivers and streams

Phys­i­cal De­scrip­tion

Adults are slen­der with a large dark spot at the front of the dor­sal fin and a smaller dark spot at the base of the tail fin. Their total body length ranges from 12 to 18 cm (30 cm max­i­mum). An­te­ri­orly, the body is hardly com­pressed, but at the cau­dal end the pe­dun­cle is com­pressed. The head is broad with a short snout and has a large oblique mouth with a small bar­bel in the groove above the upper lip. Dor­sally, they are dark olive with a dark strip along the mid­line; ven­trally, they are white, with sil­very sides. The fins are yel­low to light olive with 8 to 9 dor­sal-fin rays, 7 to 9 anal-fin rays, 13 to 18 pec­toral-fin rays, and 8 pelvic-fin rays. Creek chubs are dis­tin­guished from sim­i­lar species such as fall­fish, cut­lips min­nows, and tonguetied min­nows, by more lat­eral-line scales, and the an­te­rior mar­gin of the bot­tom lip being com­plete. Spawn­ing males de­velop breed­ing tu­ber­cles (head, snout, fins, sides, and cau­dal re­gions), are brightly col­ored (ap­ple-green above and rose-red below), and are larger in size com­pared to 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

De­vel­op­ment

Fer­til­ized creek chub eggs de­velop within the nest with no parental care. Within six days after fer­til­iza­tion, the eggs begin to hatch. The newly hatched lar­vae have slightly de­curved heads over a large yolk sac and are clas­si­fied as being in the pro­lar­vae stage. The end of this stage and be­gin­ning of the post­lar­vae stage oc­curs when the yolk has been ab­sorbed and all fins ex­cept the pelvic fin are vis­i­ble. The post­lar­vae stage lasts until the sca­la­tion, when the ju­ve­nile fish starts to re­sem­bles adult creek chubs. The en­tire lar­val stage lasts be­tween 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)

Re­pro­duc­tion

Creek chubs are promis­cu­ous, with mul­ti­ple fe­males vis­it­ing and lay­ing eggs at a few dif­fer­ent nests and males mat­ing with sev­eral dif­fer­ent fe­males. Males con­struct pit nests (one male per nest) roughly 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 (par­al­lel to the course of the stream) and pile small stones up­stream form­ing a ridge roughly 30 cm wide and 550 cm long. The male oc­cu­pies and guards the com­pleted nest, and often dri­ves off other min­now species and smaller creek chubs. If they are chal­lenged by a male of sim­i­lar size, the two may en­gage in 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 of their course, 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 lo­cal­ity of the nest is im­por­tant for male re­pro­duc­tive suc­cess. While males con­struct nests, fe­males wait nearby. Dur­ing this time, they ap­proach the male and his nest but usu­ally flee once the male ap­proaches. This be­hav­ior con­tin­ues until one 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 oc­curs, the male will pur­sue her and try to bite or hook her. When a fe­male does not flee, the male throws her into a ver­ti­cal po­si­tion and her body is en­cir­cled by his body. The male’s op­er­cle and pec­toral fin are pressed against one side of the fe­male, while his tail is pressed against her other side. This em­brace lasts for no longer than a few sec­onds, dur­ing which, 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. A ma­jor­ity of males reach sex­ual ma­tu­rity at the age of 3 years. Sex­u­ally ma­ture males de­velop breed­ing tu­ber­cles and change color, dis­tin­guish­ing them from fe­males. Sex­ual ma­tu­rity in fe­males is also reached around the age of 3 years, but some fe­males reach ma­tu­rity after one year. The num­ber of ripe ova per fe­male cor­re­lates with the fe­male's length. Ma­ture ova are large and round (0.15 to 0.2 cm in di­am­e­ter) and have a yel­low­ish color, while im­ma­ture ova are smaller and white (< 0.08 cm in di­am­e­ter). Mat­ing oc­curs for roughly 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 the males out­num­ber­ing fe­males. Ripened 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)

  • Breeding interval
    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 are as­so­ci­ated with pro­vid­ing parental care to their off­spring. ("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

Lifes­pan/Longevity

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

Be­hav­ior

Creek chubs are di­ur­nal. They 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 among lar­vae from other fish species such as long­nose daces and com­mon shin­ers. Lar­vae seek shel­ter under veg­e­ta­tion and avoid deep areas to re­duce the risk of pre­da­tion. Ju­ve­nile creek chubs school with other min­now species such as pearl daces and brassy min­nows. They oc­cupy the edge of the pools and the 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 can be very mo­bile, with move­ment both up­stream and down­stream. Their move­ment is re­lated to re­sources and pre­da­tion avoid­ance. Al­though they are very mo­bile and do change lo­ca­tions, their dis­place­ment dis­tance is not great. On av­er­age their max­i­mum range is 130 to 195 m but some travel up to 600 m. (Be­l­ica and Rahel, 2008)

Com­mu­ni­ca­tion and Per­cep­tion

Creek chubs mainly com­mu­ni­cate vi­su­ally. Dur­ing the spawn­ing sea­son, males in­ter­act with other males and in­trud­ers through as­sess­ment of in­di­vid­ual size, swim­ming pat­terns, and some­times through phys­i­cal con­tact. Pos­si­ble chem­i­cal com­mu­ni­ca­tion oc­curs when a cyprinid species is con­sumed or in­jured, re­leas­ing a pheromone alarm that is de­tected by creek chubs. If non-cyprinid fish and cray­fish are abun­dant in the en­vi­ron­ment, then creek chubs avoid cyprinid species. ("Meth­ods of study­ing the habits of fishes, with an ac­count of breed­ing habits of the horned dace", 1908; Copes, 1978; Pflieger, 1997)

Food Habits

Creek chubs are gen­er­al­ized car­ni­vores with a highly adapt­able diet. They con­sume a small amount of plant mat­ter, but this is as­so­ci­ated with mu­tual con­sump­tion of its prey. In their first few months of life, they con­sume aquatic in­sect lar­vae. As they age, they con­sume adult ter­res­trial in­sects. Fur­ther growth leads to con­sump­tion of 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

Pre­da­tion

Preda­tors in­clude larger fish such as brown trout, north­ern pike, and small mouth bass, as well as larger creek chubs. (Copes, 1978; Moshenko, 1972)

Ecosys­tem Roles

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

Com­men­sal/Par­a­sitic Species
  • Sapro­loeg­nia

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Creek chubs are eco­nom­i­cally im­por­tant as they make ex­cel­lent bait. The abun­dance of creek chubs in a given lo­cal­ity is in­creas­ingly used as an in­di­ca­tor of stream qual­ity. De­graded sites tend to have high abun­dances, cou­ple with a low di­ver­sity of other fish species. (Jor­dan, et al., 2013; Lau, et al., 2006; Pflieger, 1997)

  • Positive Impacts
  • research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

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)

Con­ser­va­tion Sta­tus

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

Con­trib­u­tors

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.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

freshwater

mainly lives in water that is not salty.

insectivore

An animal that eats mainly insects or spiders.

keystone species

a species whose presence or absence strongly affects populations of other species in that area such that the extirpation of the keystone species in an area will result in the ultimate extirpation of many more species in that area (Example: sea otter).

molluscivore

eats mollusks, members of Phylum Mollusca

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

omnivore

an animal that mainly eats all kinds of things, including plants and animals

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

piscivore

an animal that mainly eats fish

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

visual

uses sight to communicate

Ref­er­ences

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.