Fundulus zebrinus

plains killifish



Type Locality

“Rio Grande in New Mexico” (Jordan and Gilbert 1883).


Etymology/Derivation of Scientific Name

Fundulus, from the Latin name Fundus, meaning "bottom," the habitat; zebrinus, "like a zebra," a reference to the vertical bars or stripes (Pflieger 1997). Name zebrinus is substitute name for zebra preoccupied in Fundulus (Shute and Allen 1980).



Fundulus zebrinus Jordan and Gilbert 1883:891; Poss and Miller (1983).

Fundulus zebrinus zebrinus Shute and Allen 1980:531.

Plancterus zebrinus zebrinus Minckley et al. 1991:254-255.

Fundulus kansae Hubbs and Echelle 1972:150.


Kreiser et al. (2001) and Kreiser (2001) presented data supporting the recognition of two species of plains killifish: Fundulus kansae (northern plains killifish) and Fundulus zebrinus.



Maximum size: 100 mm TL (Shute and Allen 1980; Page and Burr 1991).


Coloration: Dark olive back, fading to yellowish on sides and to silvery white on the belly; 12 or more dark bands (fewer and wider on male) mark the sides. Bright red fins on large male (Koster 1957; Page and Burr 1991; Hubbs et al. 2008).


Counts: 47 (42-50) scale rows in lateral series (Texas populations; Hubbs et al. 2008). Poss and Miller (1983) reported that lateral scale row count varied from 38-58 [based on specimens from the Rio Grande (39-53); Pecos River (38-53); Colorado River, Texas (42-53); Brazos River (41-50); Red River and Washita River (39-58) populations]; dorsal fin ray count varied from 11-17 [Pecos River 14 (11-16); Colorado River, Texas 14 (11-15); Brazos River 14 (11-16); Red River and Washita River 15 (11-17) populations]; anal fin ray count varied from 9-14 [Pecos River 13 (11-14); Colorado River, Texas 13 (11-14); Brazos River 12 (9-14); Red River and Washita River 13 (12-14) populations]. Hubbs (1926) and Koster (1957) listed count of 41-49 lateral scale rows for this species.


Body shape: Compressed, moderately elongated body with large head, wide mouth, and projecting lower jaw (Koster 1957).


Mouth position: Terminal; lower lip large and fleshy (Sublette et al. 1990).


External morphology: Lateral scales large; gill slit not extending dorsal to uppermost pectoral fin ray; distance from origin of dorsal fin to end of hypural plate less than distance from origin of dorsal fin to preopercle or occasionally about equal to that distance (Hubbs et al. 1991; Hubbs et al. 2008). The least width of the preorbital (flat bone between the eye and mouth) is only one-half to two-thirds as great as diameter of the eye (Koster 1957). Fundulus zebrinus shares the following morphological characteristics with Fundulus kansae (northern plains killifish): Dorsal fin long and rounded; pectoral and pelvic fins ovate, pectorals much larger than pelvics; anal fin elongate, sharply angulate; caudal fin truncate (Sublette et al. 1990). Male has slight depression in the region of the urogenital papilla; female has an oviducal sheath surrounding the urogenital region and the anterior edge of the anal fin (Bonham 1962). Males possess small slender contact organs, hooked forward, on the anal fin and adjacent portion of the body (Hubbs 1926).


Distribution (Native and Introduced)

U.S. distribution: Reported from near the mouth of the Black River, New Mexico, where it was apparently maintained by immigration from resident populations in the adjacent Pecos River (Cowley and Sublette 1987; Sublette et al. 1990). Species found in the Rio Grande/Pecos drainage of New Mexico (Shute and Allen 1980; Hubbs and Echelle 1972). Pecos River, New Mexico (Minckley et al. 1991). Red River in Oklahoma (Kreiser et al. 1991).


Texas distribution: Species ranges from the Red River to the Pecos River (Hubbs et al. 2008). Kreiser (2001) and Kreiser et al. (2001) reported collection of this species from the Pecos, Brazos and Red Rivers (the Colorado River was not sampled in the study). Warren et al. (2000) listed the following drainage units for distribution of Fundulus zebrinus in the state: Galveston Bay (including minor coastal drainages west to mouth of Brazos River), Brazos River, Colorado River. Species found in Independence Creek (largest tributary of lower Pecos River; Bonner et al. 2005); Pedernales River (tributary of the Colorado River; Birnbaum 2005); lower Rio Grande (Minckley et al. 1991). Shute and Allen (1980) listed distribution of F. zebrinus (= Fundulus z. zebrinus) in the Trinity, Brazos, Colorado, and Rio Grande/Pecos drainages of Texas. Collected from the Big Bend region at Garden Springs (mouth of Tornillo Creek and mouth of Terlingua Creek); most likely introduced by bait bucket release (Hubbs 1957).


Abundance/Conservation status (Federal, State, NGO)

Populations in the southern United States are currently stable (Warren et al. 2000). Widespread and locally common (Minckley et al. 1991). Ostrand and Wilde (2004) reported that Fundulus zebrinus was a dominant species in pools sampled in the upper Brazos River drainage, composing 7.1% of the fish collected. In Austin, Texas, naturally occurring population in Waller Creek (Colorado River) on The University of Texas campus was eliminated by chemical pollution around 1946 (Edwards 1976; Poss and Miller 1983).


Habitat Associations

Macrohabitat: Found in shallows of ponds and streams at lower elevations in the Pecos Valley (Koster 1957).


Mesohabitat: Shallow, sandy, river edges, channels, and backwaters (Minckley et al. 1991). According to Ostrand and Wilde (2001), this species has high thermal, low dissolved oxygen, and high salinity tolerances: mean critical thermal maxima = 42.0 ± 0.2°C; salinity tolerance = 43 ± 0.05‰; mean minimum dissolved oxygen tolerance = 1.25 ± 0.09 mg/L. A laboratory study suggested a relatively narrow optimal oxygen concentration for F. zebrinus; species apparently possesses great capacity to sense and respond to oxygen conditions, which is adaptive toward life in western streams (Hill et al. 1978). Griffith (1974) reported tolerance of salinities as high as 89‰. Ostrand and Wilde (2004) collected species from isolated pools in the upper Brazos River drainage, Texas; found in pools with salinities as high as 110‰. Species occurs abundantly in the saline waters of the Pecos River, Texas (Hubbs 1957; Rhodes and Hubbs 1992). F. zebrinus was one of seven species (all tolerant of a wide range of salinities) in communities that dominated areas of high conductivity, in the Pecos River drainage, Texas (Linam and Kleinsasser 1996). Collected from the Colorado River, Texas, from sandy bottomed draws that periodically go dry; water was highly saline to the taste, and salt encrustaceans were present on dry areas of the bed (Echelle et al. 1977).




Spawning season: In southwestern Oklahoma (Red River drainage), Echelle (1970) observed species spawning as early as March 28 and as late as October 27.


Spawning location: In Mirror Lake and Lake Francis, (Pecos River) New Mexico, Fundulus zebrinus spawned on substrates such as gypsum boulders, bare sediment and vegetation-covered sediment (Kodric-Brown and Mazzolini 1992).


Reproductive strategy: Gravid females were pursued by either single males, pairs of males or by groups of several males; a spawning pair settled to the substrate where the female deposited eggs; spawning pair either traveled to another site or the pair parted (Kodric-Brown and Mazzolini 1992); species observed to be interspecifically territorial in association with the Pecos pupfish (Cyprinodon pecosensis). Echelle (1970) observed Fundulus zebrinus (Red River drainage, Oklahoma) noting that it is a bottom spawner; males were observed attempting to defend breeding territories against Red River pupfish (Cyprinodon rubrofluviatilis) males.




Age at maturation:






Food habits: Echelle (1970) observed individuals (Red River drainage, Oklahoma) feeding at the surface as well as the bottom; bottom feeding behavior involved “digging” and “nipping”. Rabe et al. (1973) identified 12 algal genera from the foreguts and/or hindguts of specimens from Oscar Creek, Oklahoma, and 28 algal genera were cultured from Coffeepot Creek, Oklahoma specimens.




Phylogeny and morphologically similar fishes

Fundulus zebrinus differs from F. kansae (northern plains killifish) in having larger scales, larger eyes and a more robust body; F. zebrinus has 47 (42-50) scale rows in lateral series, the large male of the species having bright red fins; F. kansae has 53 (47-60) scale rows in lateral series, the large male of the species having yellow-orange fins (Hubbs 1926; Page and Burr 1991; Hubbs et al. 2008). Fundulus kansae is not found in the Pecos, Red, and Brazos rivers (Kreiser 2001; Kreiser et al. 2001). F. zebrinus has 12 or more vertical dark bands marking the sides; these bars distinguishing the species from live-bearers of similar shape (Koster 1957).


A genetic survey revealed that introduced Fundulus kansae populations from the San Juan River drainage (site: Cross Creek Canyon, San Juan Co., Utah) grouped with populations of F. zebrinus from the Brazos, Red and Pecos rivers (Kreiser et al. 2000).


Fundulus zebrinus occurs sympatrically with the Red River pupfish (Cyprinodon rubrofluviatilis) in the Red and Brazos Rivers and is closely associated, ecologically and phylogenetically, with the species (Echelle 1970; Echelle et al. 1972).


Host Records



Commercial or Environmental Importance





Birnbaum, J.S. 2005. Associations of watershed and instream environmental factors with aquatic macrofauna in tributaries of the Pedernales River, Texas. M.S. Thesis, Texas A&M University, College Station. 112 pp.

Bonham, L.E. 1962. Ecology of a saline spring, Boone's Lick. M.A. Thesis, Univ. Mo., Columbia. 89 pp.

Bonner, T.H., C. Thomas, C.S. Williams, and J.P. Karges. 2005. Temporal assessment of a west Texas stream fish assemblage. The Southwestern Naturalist 50(1):74-106.

Cowley, D.E., and J.E. Sublette. 1987. Distribution of fishes in the Black River drainage, Eddy County, New Mexico. Southwestern Naturalist 32(2):213-221.

Echelle, A.A. 1970. Behavior and ecology of the Red River pupfish, Cyprinodon rubrofluviatilis. Ph.D. Dissertation, University of Oklahoma, Norman. 125 pp.

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

Echelle, A.A., A.F. Echelle, and L.G. Hill. 1972. Interspecific interactions and limiting factors of abundance and distribution in the Red River pupfish, Cyprinodon rubrofluviatilis. American Midland Naturalist 88(1):109-130.

Edwards, R.J. 1976. Relative and seasonal abundance of fish fauna in an urban creek ecosystem. Unpublished MA thesis, University of Texas, Austin.

Griffith, R.W. 1974. Environment and salinity tolerance in the genus Fundulus. Copeia 1974(2):319-331.

Hill, L.G., W.J. Matthews, and G. D. Schnell. 1978. Locomotor reactions to two cyprinodontid fishes to differences in dissolved oxygen concentrations. The Southwestern Naturalist 23(3):397-400.

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

Hubbs, C., and A.A. Echelle. 1972. Endangered and non-game fishes of the upper Rio Grande basin. pp. 147-167 in: Symposium on rare and endangered wildlife of the southwestern United States. New Mexico Dept. Game and Fish, Santa Fe.

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.


Hubbs, C., R.J. Edwards, and G.P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement, 2nd edition 43(4):1-87.

Hubbs, C. L. 1926. Studies of the fishes of the order Cyprinodontes. VI. Material for a revision of the American genera and species. Misc. Publ. Mus. Zool. Univ. Mich. 16:1-86.


Jordan, D.S., and C.H. Gilbert. 1883. Synopsis of the fishes of North America. U.S. Nat. Mus. Bull. 16:1-1018.


Kodric-Brown, A., and Mazzolini P. 1992. The breeding system of pupfish, Cyprinodon pecosensis: effects of density and interspecific interactions with the killifish, Fundulus zebrinus. Environmental Biology of Fishes 35:169-176.


Koster, W.J. 1957. Guide to the Fishes of New Mexico. University of New Mexico Press, Albuquerque. 116 pp.

Kreiser, B.R. 2001. Mitochondrial cytochrome b sequences support recognition of two   cryptic species of plains killifish, Fundulus zebrinus and Fundulus kansae. American Midland Naturalist 146:199-209.


Kreiser, B.R., J.B. Mitton, and J.D. Woodling. 2000. Single versus multiple sources of introduced populations identified with molecular markers: a case study of a freshwater fish. Biological Invasions 2:295-304.

Kreiser, B.R., J.B. Mitton, and J.D. Woodling. 2001. Phylogeography of the plains killifish, Fundulus zebrinus. Evolution 55(2):339-350.

Linam, G.W., and L.J. Kleinsasser. 1996. Relationship between fishes and water quality in the Pecos River, Texas. Texas Parks and Wildlife Department, River Studies Report No. 9, Austin.

Minckley, W.L., G.K. Meffe, and D.L. Soltz. 1991. Conservation and management of short-lived fishes: the Cyprinodontoids. Pp. 247-282 in: Minckley, W.L., and J.E. Deacon (Eds.). Battle Against Extinction: Native Fish Management in the American West. The University of Arizona Press, Tucson, Arizona. 517 pp.

Ostrand, K.G., and G.R. Wilde. 2001. Temperature, dissolved oxygen, and salinity tolerances of five prairie stream fishes and their role in explaining fish assemblage patterns. Trans. Amer. Fish. Soc. 130:742-749.

Ostrand, K.G., and G.R.Wilde. 2004. Changes in prairie stream fish assemblages restricted to isolated streambed pools. Trans. Amer. Fish. Soc. 133:1329-1338.

Page, L. M., and B. M. Burr.  1991.  A Field Guide to Freshwater Fishes of North America, north of Mexico.  Houghton Mifflin Company, Boston, 432 pp.

Poss, S.G., and R.R. Miller. 1983. Taxonomic status of the plains killifish, Fundulus zebrinus. Copeia 1983(1):55-67.

Pflieger, W.L.  1997.  The Fishes of Missouri.  Missouri Department of Conservation, Jefferson City, 372 pp.

Rabe, J.R., A.A. Echelle, and H.E. Schlicht. 1973. Viability of algae in digestive tracts of 2 cyprinodontids. Progressive Fish-Culturist 35(3):147-149.

Rhodes, K., and C. Hubbs. 1992. Recovery of Pecos River fishes from a Red Tide fish kill. The Southwestern Naturalist 37(2):178-187.

Shute, J.R., and A.W. Allen. 1980.  Fundulus zebrinus (Jordan and Gilbert), Plains killifish. pp. 531 in D. S. Lee et al., Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Sublette, J.E., M.D. Hatch, and M. Sublette. 1990. The Fishes of New Mexico. University of New Mexico Press, Albuquerque. 393 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, Conservation 25(10):7-29.