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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Gulf Killifish

Taxonomy: available through www.itis.gov

Identification: The Gulf killifish is one of the largest killifish species (to 18 cm), with a blunt head and short snout.  The caudal peduncle is relatively deep.  Mandibular pores = 5.  It is yellowish or pale below, darker on the back, with many small pale spots, mottling and inconspicuous bars.  Spots may be pearly in colour.  From Robins et al. 1986.

Although the species is relatively drab for the majority of the year, breeding males are brilliant.  They are deep blue dorsally, and have blue median fins with light blue spots and yellow-orange margins.  Some males develop orange-red anal fins with red spots; paired fins are also yellow-orange with red spots on the pectoral fin (Ross 2001). 

Two subspecies:  Fundulus grandis grandis from Veracruz, Mexico eastward along the coast of the Gulf of Mexico to southwestern Florida.  Fundulus grandis saguanus occurs in the Florida Keys and Cuba (Relyea 1983).

Size: 18 cm.

Native Range: Fresh and brackish waters from northeastern Florida to Key West and northern Gulf of Mexico to Cuba (Lee et al. 1980 et seq.; Robins and Ray 1986).  On the Gulf Slope is is native to the Nueces, San Antonio Bay, Colorado, Brazos, Galveston Bay, Sabine Lake, and Calcasieu drainages (Conner and Suttkus 1986); and the lower Rio Grande (Smith and Miller 1986).

Texas distribution: Occurs in large numbers in Brazos River, Hill and Bosque Counties, over 400 km from the Gulf Coast (Hillis et al. 1980).

Interactive maps: Point Distribution Maps

Ecology: Primarily estuarine, the killifishes (Cyprinodontidae) are inshore fishes associated with a variety of low-salinity habitats (including marshes, seagrass beds, oyster, etc.).  However, most killifish species have wide salinity tolerances, and can sometimes be found in habitats ranging from hypersaline tidal pools to freshwater reaches.  The Gulf killifish is no exception, and can tolerate wide variances in salinity (Crego and Peterson 1997).

The Gulf killifish feeds throughout the water column, consuming fishes (e.g., killifishes and anchovies), terrestrial insects on the water surface as well as benthic algae and crustaceans (Ley et al. 1994; Rozas and LaSalle 1990).  When allowed access to a flooded marsh, feeding is increased (Rozas and LaSalle 1990).  The spawning season extends from March to September (Greeley and MacGregor 1983).  Eggs are deposited on vegetation during a spring high tides and left to develop exposed to the air.  On the next high tide (usually 11-12 days later), the eggs are inundated and hatch (Greeley and MacGregor 1983). 

Means of Introduction: The fish was introduced through bait bucket release into New Mexico and Texas. It was stocked intentionally but unsuccessfully in Hawaii for mosquito control in 1905, with specimens from Texas (Brock 1960; Maciolek 1984; Randall 1987).

Often introduced as a “bait minnow” and occurs widely in the Brazos, Rio Grande and Pecos Basins (Hubbs et al. 1991, 2008).

"Fundulus grandis is commonly used as a bait fish in Texas (Hoese and Moore, Fishes of the Gulf of Mexico. Texas, Louisiana, and Adjacent Water, Texas A&M Univ. Press, 1978), and the populations of F. grandis in the Brazos River between Lake Whitney and Lake Brazos probably resulted from bait releases or escapes. Lake Whitney Dam is a popular sport-fishing area, and since F. grandis seems to be one of the dominant fishes in the area in terms of numbers, it is likely that the dam area was the original site of introduction. Populations of F. grandis immediately above Lake Brazos are small, indicating recent establishment of this species in that area. It is possible that Lake Brazos does not represent a barrier to F. grandis, and that Brazos River populations are still expanding. Pandale Crossing is also a sport- fishing area, and populations are established along the Pecos River for at least 50 km below this point; again bait release may have been the means of establishment. The Starr Co. population of F. grandis may be native since several other species of estuarine fishes occur naturally above Falcon Dam (Hubbs, Southwest. Nat. 2:84- 104, 1957). The single specimen of F. grandis from Lake Balmorhea was un- doubtedly introduced along with the Cyprinodon variegatus which are common there" [Hillis et al. 1980].

Status: Established in Texas. Sublette et al. (1990) reported that it was extirpated in New Mexico, but Burr (personal communication) believes the species is still established in lower Pecos River as of 1992.  Populations from the 1905 Hawaii introduction are reported as having failed (Brock 1960; Maciolek 1984; Randall 1987; Mundy 2005); however, a population was reported as reproducing in Pearl Harbour (Bishop Museum 2000).  It is unclear whether the Pearl Harbour population is the result of the 1905 introduction or a subsequent re-introduction.

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

Remarks: A common live bait in its natural range, often called "mud minnow", "chubs"; or "cigar minnow" or "bull minnow" in coastal Mississippi (Ross 2001).  The species is also commonly used in toxicity tests.

References: (click for full references)

Bishop Museum. 2000. Pearl Harbor Legacy Project. Available URL at http://hbs.bishopmuseum.org/pdf/tr-16.pdf.

Brock, V. E.  1960.  The introduction of aquatic animals into Hawaiian waters.  International Revue der Gesamten Hydrobiologie 45: 463-480.

Burr, B. - Southern Illinois University, Carbondale, IL.

Crego, G. J. and M. S. Peterson.  1997.  Salinity tolerance of four ecologically distinct species of Fundulus (Pisces: Fundulidae) from the northern Gulf of Mexico.  Gulf of Mexico Science 1997: 45-49.

Hillis, L. G., E. Milstead, and S. L. Campbell. 1980. Inland records of Fundulus grandis (Cyprinodontidae) in Texas. Southwest. Nat. 25(2):271-272.

Hubbs, C., R. J. Edwards, and G. P. Garrett. 1991. An annotated checklist of freshwater fishes of Texas, with key to identification of species. Texas Journal of Science, Supplement 43(4):1-56.

Lee, D. S., C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. 1980 et seq. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, NC.

Ley, J. A., C. L. Montague and C. C. McIvor.  1994.  Food habits of mangrove fishes:  a comparison along estuarine gradients in northeastern Florida Bay.  Bulletin of Marine Science 54: 881-899.

Maciolek, J. A. 1984. Exotic fishes in Hawaii and other islands of Oceania. Pages 131-161 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., editors. Distribution, biology, and management of exotic fishes. The Johns Hopkins University Press, Baltimore, MD.

Mundy, B. C.  2005.  Fishes of the Hawaiian Archipelago.  Bishop Museum Bulletins in Zoology, Number 6.

Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Field Guide Series, volume 42. Houghton Mifflin Company, Boston, MA.

Randall, J. E. 1987. Introductions of marine fishes to the Hawaiian Islands. Bulletin of Marine Science 41(2):490-502.

Relyea, K.  1983.  A systematic study of two species complexes of the genus Fundulus (Pisces: Cyprinodontidae).  Bulletin of the Florida State Museum, Biological Sciences 29: 1-64.

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

Rozas, L. P. and M. W. LaSalle.  1990.  A comparison of the diets of Gulf killifish, Fundulus grandis Baird and Girard, entering and leaving a Mississippi brackish marsh.  Estuaries 13: 332-336.

Robins, C. R., G. C. Ray, and J. Douglass. 1986. A field guide to Atlantic Coast fishes of North America. The Peterson Guide Series, volume 32. Houghton Mifflin Company, Boston, MA.

Sublette, J. E., M. D. Hatch, and M. Sublette. 1990. The fishes of New Mexico. New Mexico Department of Game and Fish, University of New Mexico Press, Albuquerque, NM. 393 pp.

Other Resources:

Author: Schofield, P.J., and Fuller, P.

Peer Review Date: 1/28/2013

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.