Pimephales promelas

fathead minnow



Type Locality

Pond near Lexington, Kentucky (Rafinesque, 1820).


Etymology/Derivation of Scientific Name

Pimephales, Greek, meaning “fat head;” promelas, from the Greek pro, meaning “before or in front”, and melas, meaning “black”, in reference to the black head of breeding males (Ross 2001).



Pimephales promelas Rafinesque 1820:53.

Pimephales milesi Cope, Jordan and Evermann 1896-1900:217.



Maximum size: 101 mm (3.98 in) TL (McCarrahar and Thomas 1968).


Life colors: Caudal spot faint or absent and not separated from longitudinal streak by a clear space (Hubbs et al. 1991). Back and upper sides dark olive to dark gray, becoming white to yellow on undersides. The dusky or gray midlateral band is best developed in juveniles. Fins clear to slightly milky, except for dorsal fin, which may have dark blotch on the midanterior region of the fin. Thin black lines outline divisions of lateral muscle bands (myosepta) resulting in distinctive herring-bone pattern that is most notable midlaterally (Ross 2001). Breeding males much darker overall, with black heads and fins, and two golden brown vertical bands on sides; one band just posterior to operculum and the other extends from dorsal fin base ventrally to pelvic fin base (Unger 1983). Intensity of the bands may appear or disappear in seconds in response to levels of aggression or sexual activity (McMillan 1972). Ripe females more silvery or olive.


Pharyngeal teeth count: 0,4-4,0 (Hubbs et al. 1991).


Counts: 7 anal fin soft rays (Hubbs et al. 1991). 44-50 lateral line scales, 14-20 gillrakers total (4-6 upper, 10-14 lower), 8 dorsal rays, 14-17 pectoral soft fin rays, and 8 (7-8) pelvic soft fin rays (Ross 2001).


Body shape:  Laterally compressed minnow with a blunt snout. Top of head and nape slightly flattened (Ross 2001). 


Mouth position: Terminal, slightly upturned mouth (Ross 2001).


Morphology: Head length goes into standard length 3.6-4.3 times; eye diameter goes into snout length 0.8-1.1 times and into head length 3.1-4.2 times. Predorsal scales crowded, much smaller than those on rest of body; first two obvious dorsal fin rays stout, well separated from the following well developed but unbranched ray by a membrane; lower lip thin, without a fleshy lobe; lateral line usually not decurved, either straight or with a broad arch; 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).  Body depth is greatest anterior to the dorsal fin; body depth goes into standard length 3.6-5.1 times and is proportionately deeper in larger fish (Ross 2001).  Lateral line usually incomplete with 7-40 pored scales. Number of pored scales increases with fish size and these may be interrupted (Ross 2001). Breeding males develop a large, mucus-secreting, fleshy pad on the nape (Smith and Murphy 1974; Smith 1978) and 16 large tubercles in three rows on the snout. Females develop an enlarged urogenital papilla approximately one month prior to spawning (Flickinger 1969).  Intestine long, more than twice the length of the body (Hubbs et al. 1991).


Distribution (Native and Introduced)

U.S. distribution: Widespread east of the Rocky Mountains in North America (Hubbs et al 1991).


Texas distribution: Minnow may be found throughout much of the state, presumably as a result of bait releases (Hubbs et al 1991). Warren (2000) listed this species as inhabiting the following drainages units within the state: 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), Colorado River unit, San Antonio Bay unit (including minor coastal drainages west of mouth of Colorado River to mouth of Nueces River), Nueces River.


[Additional literature noting collection of this species from Texas locations includes, but is not limited to the following: Hubbs (1957); South Canadian River (Arkansas drainage; Echelle et al. 1977); Tornillo Creek (Brewster Co.; Hubbs and Wauer 1973); N. Sulpher, S. Sulpher, and Middle Sulpher Rivers (Carroll et al. 1977).]


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

Populations in the southern United States are currently secure (Warren 2000).


Habitat Associations

Macrohabitat: Widely distributed in ponds, reservoirs, and pools and backwaters of streams. Most common in quiet water over mud substrata (Minckley 1959; Deacon 1961).


Mesohabitat: Tolerant of poor water quality, including low oxygen; seem to do well in marginal habitats (Cross 1967). Tendency to occur in isolated areas with few other resident fish species, suggesting they are poor competitors with other fishes (Hubbs and Cooper 1938; Starrett 1950). Tolerant of high turbidity and frequently found in sluggish prairie streams; abundant at localities with soft substrates (Rose and Echelle 1981).



Spawning season: May through September in 19-30°C water (Ross 2001).


Spawning location: Speleophils; hole nesters (Simon 1999). Shallow water in usually on top of sand substratum; if sand is not available, under objects such as plant stems, fence posts, etc... Spawning may occur under floating objects (Wynne-Edwards 1933; McCarrahar and Thomas 1968; Andrews and Flickinger 1974; Gale and Buynak 1982).


Reproductive strategy: After the male excavates a nest, he actively drives away males and females, including ripe females (McMillan and Smith 1974), as females may enter the nesting site to eat eggs already laid (Unger 1983). A persistent ripe female is ultimately allowed into the nesting area to spawn (Ross 2001). Males court females with static and moving displays, and leading behavior. Both parents then swim over the nest and eggs are released and fertilized, deposited on the ceiling of the nest site (Cole and Smith 1987). Males may spawn with several females, and the eggs in one site may be at different stages of development (McMillan and Smith 1974). Eggs are firmly fastened to the substratum; once detached do not adhere again (Gale and Buynak 1982). A male can accumulate 12,000 eggs at his nesting site (Markus 1934; Andrews and Flickinger 1974; Gale and Buynak 1982). Males guard eggs until they hatch (Wynne-Edwards 1933).  Males will defend their site from other males with lateral displays (Unger 1983) and will sometimes engage in snout-to-snout butting contests (McMillan 1972).


Fecundity: A single females may produce 6803-10164 eggs, over the entire spawning season, and may have participated in 16-26 spawning sequences. A female might produce from 9-1136 eggs in a day (Gale and Buynak 1982). Hatching occurs in approximately 13 days at 15°C (59°F), decreasing to 4 days at 25°C (77°F) (Markus 1934; Andrews and Flickinger 1974).


Age at maturation: Markus (1934) and Dobie et al. (1956) found that young hatched in late May in Iowa and Missouri had reached sexual maturity and reproduced by late July of the same year.


Migration: During periods of high stream discharge, fathead minnows showed downstream movement in a small Minnesota stream (Schlosser 1995).


Growth and population structure: In Ohio, young of year ranged from 13-64 mm (0.51-2.52 in) in length (TL); around 1 year length ranged from 25-76 mm (0.98-3.00 in); adults usually 41-76 mm (1.61-2.99) in length (Trautman 1981).


Longevity: Maximum longevity is apparently 2-3 years (Schlosser and Ebel 1989). Postspawning mortality in populations varies, with up to 80-85% dying in one population (Markis 1934), and a survival rate 100% in another (Gale and Buynak 1982).


Food habits: Primarily benthic feeders; filling digestive tracts with mud or silt which are rich in numerous species of algae and protozoa, these constituting the major food source. Diatoms and green algae are particularly common in diet; occasionally known to eat small crustaceans (Coyle 1930; Starrett 1950). Occasionally consume various aquatic insects (Forbes 1883).


Phylogeny and morphologically similar fishes

Juvenile creek chubs (Semotilus atromaculatus) are very similar to Pimephales promelas, but have a much larger jaw, 11 or fewer gill rakers, a complete lateral line, and the dorsal fin pigment is at the anterior base rather than as a median blotch on the midanterior region of the dorsal fin (Etnier and Starnes 1993). While similar, the bullhead minnow (P. vigilax)  is more slender, lacks herringbone lines, and has a complete lateral line (Page and Burr 1991).


Host Records

     Ligula intestinalis (McCarraher and Thomas 1968). Hoffman (1967) listed species of Protozoa (2), Trematoda (10), Cestoda (5), Nematoda (2), and Crustacea (1).


Commercial or Environmental Importance

A strain referred to as the “rosy-red” minnow, both sexes having red-orange body and fins, developed primarily for the pet trade (Page and Burr 1991). Most fatheads sold locally for bait come from Wisconsin, Michigan, and Minnesota (Etnier and Starnes 1993); in Arkansas, ranking second as a bait species in importance to the aquaculture industry (Robison and Buchanan 1988).



Andrews, A. K., and S. A. Flickinger. 1974. Spawning requirement and characteristics of the fathead minnows. Proc. S.E. Assoc. Game Fish Comm. 27:759-766.

Carroll, J.H., Jr., D. Ingold, and M. Bradley. 1977. Distribution and species diversity of summer fish populations in tow channelized rivers in northeast Texas. The Southwestern Naturalist 22(1):128-134.

Cole, K. S., and R. J. F. Smith. 1987. Male courting behaviour in the fathead minnow, Pimephales promelas. Env. Biol. Fish. 18(3):235-239.

Coyle, E. E. 1930. The algal food of Pimephales promelas. Ohio J. Sci. 30(1):23-35.

Cross, F. B. 1967. Handbook of fishes of Kansas. Misc. Publ. Mus. Nat. Hist. Univ. Kansas. 45:1-37.

Deacon, J. E. 1961. Fish populations, following a draught, in the Nesho and Marais des Cygnes Rivers of Kansas. Mus. Nat. Hist. Univ. Kans. 13(9):359-427.

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.

Echelle, A.A., A.F. Echelle, and F.B. Cross. 1977. First records of Cyprinodon rubrofluviatilis  (Cyprinodontidae) from the Colorado and Arkansas River syatems, Texas. The Southwestern Naturalist 22(1):142-143.

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

Flickenger, S.A. 1969. Determination of sexes in the fathead minnow. Trans. Amer. Fish. Soc. 98(3):526-527.

Forbes, S. A. 1883. The food of the smaller freshwater fishes. Bull. Ill. St. Lab. Nat. Hist. 1(6):65-94.

Gale, W. F., and G. L. Buynak. 1982. Fecundity and spawning frequency of the fathead minnow - a fractional spawner. Trans. Amer. Fish. Soc. 111(1):35-40.

Hoffman, G.L. 1967. Parasites of North American Freshwater Fishes. University of California Press, Los Angeles. 486 pp.

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

Hubbs, C., and R. Wauer. 1973. Seasonal changes in the fish fauna of Tornillo Creek, Brewster County, Texas. The Southwestern Naturalist 17(4):375-379.

Hubbs, C. L. and G. P. Cooper. 1938. Minnows of Michigan, pp 1-47. Rev. ed. Bull., no 8, Cranbrook Institute of Science, Bloomfield Hills, Mich.

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.  The Texas Journal of Science, Supplement, 43(4):1-56

Jordan, D.S., and B.W. Evermann. 1896-1900. The Fishes of North and Middle America. Bull. U.S. Nat. Mus. 47(1-4):3313 p. + 392 pls.

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McCarrahar, D. B., and R. Thomas. 1968. Some ecological observations on the fathead minnow, Pimephales promelas, in the alkaline waters of Nebraska. Trans. Amer. Fish. Soc. 97:52-55.

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McMillan, V. E. and R. J. F. Smith. 1974. Agonistic and reproductive behavior of the fathead minnow (Pimephales promelas Rafinesque). Z. Tierpsychol. 34:25-58.

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

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

Schlosser, I. J. 1995. Dispersal, boundary processes, and trophic-level interactions in streams adjacent to beaver ponds. Ecology 76(3):908-925.

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Smith, R.J.F. 1978. Seasonal changes in the histology of the gonads and dorsal skin of the fathead minnow, Pimephales promelas. Can. J. Zool. 56(10):2103-2109.

Smith, R.J.F., and B.D. Murphy. 1974. Functional morphology of the dorsal pad in fathead minnows (Pimephales promelas Rafinesque). Trans. Amer. Fish. Soc. 103(1):65-72.

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Unger, L. M. 1983. Nest defense by deceit in the fathead minnow, Pimephales promelas. Behav. Ecol. Sociobiol. 13:125-130.

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