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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: Pike Killifish

Synonyms and Other Names: pike top live bearer, pike topminnow, picudito.

Taxonomy: available through www.itis.gov

Identification: Distinguishing characteristics and illustrations were given by Rosen and Bailey (1963), Page and Burr (1991), and Howells (1992). The species is included in identification keys of Greenfield and Thomerson (1997). Photographs also appeared in Bussing (1987), Dawes (1991), Sakurai et al. (1993), and Wischnath (1993).

The body is dark grey dorsally and fades lighter ventrally. Several rows of black spots occur along the side, and a larger black spot is visible along the caudal peduncle (but is sometimes faded). The pike killifish has long jaws that form a pointed beak (similar to Esox) and contain large teeth. The dorsal-fin origin is well behind the anal-fin origin. The largest species within the family Poeciliidae. From Page and Burr (1991) and Miller et al. (2005).

Size: 20 cm SL

Native Range: The species is native to the Atlantic slope from Veracruz, Mexico south to the Yucatan, Guatemala and Belize, the Atlantic drainages of Honduras and Guatemala, and to Costa Rica (Rosen and Bailey 1963; Reis et al. 2003; Miller et al. 2005).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Most females larger than 75 mm SL and males larger than 55 mm SL are sexually mature. Average brood size is approximately 99, and larger females tend to have larger broods (up to about 320). In south Florida, reproduction continues year-round, and females are able to store viable sperm for several months. Male courtship displays are described by Horth (2004). The young are remarkably precocial; within one day of their birth, they pursue, capture, and eat prey. Adults are primarily piscivorous, and in south Florida eat mosquitofish, mollies, and other pike killifishes as their primary diet. Information from Turner and Snelson (1984) except where noted otherwise.

Means of Introduction: This species was introduced into south Florida in 1957 when individuals reared for medical research purposes were released into a local canal (Belshe 1961). Those found in Hillsborough County in 1997 were escapees from a nearby ornamental fish farm (Nico, personal communication). The Texas introduction was probably an aquarium release (Howells 1992).

Status: Established in southern Florida. The Key Largo, Florida, population apparently did not become established (Courtenay and Meffe 1989). A population was present and possibly established in the San Antonio area of Texas. However, the species was absent in later samples and the population was assumed to have been extirpated (Hubbs et al. 1978; Howells 1992).

Impact of Introduction:

Summary of species impacts derived from literature review. Click on an icon to find out more...

Ecological	Human Health

The pike killifish is a piscivore that has been reported to reduce populations of eastern mosquitofish Gambusia holbrooki and other native poeciliid and cyprinodontoid populations in areas where it has been introduced (Belshe 1961; Courtenay and Meffe 1989; Greenwood 2012), and potentially competing for food resources with juvenile snook. Harms and Turingan (2012) found that pike killifish will consume shrimp in addition to fish, and suggest that this dietary flexibility has contributed to invasion success in south Florida.

Remarks: The Florida population is descended from stock that is thought to have come from the Yucatan peninsula (Belshe 1961); it is the subspecies B. b. maxillosus (Rosen and Bailey 1963; Page and Burr 1991). In Florida, reproduction has been recorded in salinities up to at least 35 parts per thousand (Turner and Snelson 1984). Northward expansion of B. belizanus is likely limited by the lower limit of cold temperature tolerance (~9°C; Shafland and Pestrak 1982), but local densities are probably controlled by a variety of physiochemical variables (Kerfoot et al. 2011) and predation. 

Voucher specimens: Florida (CAS 78327; FSBC 18196; NCSM 29039 and others; OSUM 18155; UF - many collections; UMMZ 178973; USNM 342652); Texas (TNHC 44301).

References: (click for full references)

Barron, J.L. 1964. Reproduction and apparent over-winter survival of the sucker-mouth armoured catfish, Plecostomus sp., in the headwaters of the San Antonio River. Texas Journal of Science 16:449.

Belshe, J.F. 1961. Observations of an introduced tropical fish (Belonesox belizanus) in southern Florida. Unpublished master's thesis, University of Miami, Coral Gables.

Bussing, W.A. 1987. Peces de las aguas continentales de Costa Rica. Editorial de la Universidad de Costa Rica, San Jose.

Courtenay, W.R., Jr., and G.K. Meffe. 1989. Small fishes in strange places: a review of introduced poeciliids. 319-331 in G.K. Meffe, and F.F. Snelson, Jr., eds. Ecology and evolution of livebearing fishes (Poeciliidae). Prentice Hall, Englewood Cliffs, NJ.

Courtenay, W.R., Jr., H.F. Sahlman, W.W. Miley, II, and D.J. Herrema. 1974. Exotic fishes in fresh and brackish waters of Florida. Biological Conservation 6: 292-302.

Dawes, J.A. 1991. Livebearing fishes. A guide to their aquarium care, biology, and classification. Blandford Press, London, England.

Greenfield, D.W., and J.E. Thomerson. 1997. Fishes of the continental waters of Belize. University Press of Florida, Gainesville, FL.

Greenwood, M.F.D. 2012. Assessing effects of the nonindigenous pike killifish on indigenous fishes in Tampa Bay, Florida, using a weighted-evidence approach. Transactions of the American Fisheries Society 141:84-99.

Harms, C.A., and R.G. Turingan. 2012. Dietary flexibility despite behavioral stereotypy contributes to successful invasion of the pike killifish, Belonesox belizanus, in Florida, USA. Aquatic Invasions 7(4):547-553.

Horth, L. 2004. A brief description of the courtship display of male pike killifish (Belonesox belizanus). Florida Scientist 67: 159-165.

Howells, R.G. 1992. Annotated list of introduced non-native fishes, mollusks, crustaceans and aquatic plants in Texas waters. Texas Parks and Wildlife Department, Management Data Series 78, Austin, TX.

Hubbs, C., T. Lucier, G.P. Garrett, R.J. Edwards, S.M. Dean, E. Marsh, and D. Belk. 1978. Survival and abundance of introduced fishes near San Antonio, Texas. Texas Journal of Science 30: 369-376.

Kerfoot, J.R. Jr., J.J. Lorenz, and R.G. Turingan. 2011. Environmental correlates of the abundance and distribution of Belonesox belizanus in a novel environment. Environmental Biology of Fishes 92:125-139. http://dx.doi.org/10.1007/s10641-011-9822-2

Loftus, W.F., and J.A. Kushlan. 1987. Freshwater fishes of southern Florida. Bulletin of the Florida State Museum of Biological Science 31: 147-344.

Loftus, W.F., G. Ellis, M. Zokan, and J. Lorenz. 2004. Inventory of freshwater fish species within the Big Cypress National Preserve: the basis for a long-term sampling program. U.S. Geological Survey fact sheet 2004-3131.

Lorenz, J.J., C.C. McIvor, G.V.N. Powell, and P.C. Frederich. 1997. A drop net and removable walkway for sampling fishes over wetland surfaces. Wetlands 17: 346-359. 

Miley, W.W. 1978. Ecological impact of the pike killifish, Belonesox belizanus Kner (Poeciliidae), in southern Florida. Unpublished master's thesis, Florida Atlantic University, Boca Raton.

Miller, R.R., W.L. Minckley, and S.M. Norris. 2005. Freshwater fishes of Mexico. The University of Chicago Press, Chicago, IL.

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.

Reis, R.E., S.O. Kullander and C.J. Ferrais, Jr. 2003. Check list of the freshwater fishes of South and Central America. Museu de Ciências e Tecnologia, Pontifícia Universidade Católica do Rio Grande do Sul. EDIPUCRS, Porto Alegre, Brasil. 

Rosen, D.E., and R.M. Bailey. 1963. The poeciliid fishes (Cyprinodontiformes), their structure, zoogeography, and systematics. Bulletin of the American Museum of Natural History 126:1-176.

Sakurai, A., Y. Sakamoto, and F. Mori. 1993. Aquarium fish of the world: the comprehensive guide to 650 species. Chronicle Books, San Francisco, CA.

Shafland, P.L., and J.M. Pestrak. 1982. Lower lethal temperatures for fourteen non-native fishes in Florida. Environmental Biology of Fishes 7(2):149-156.

Tilmant, J.T. 1999. Management of nonindigenous aquatic species in the U.S. National Park System. National Park Service.

Turner, J.S., and F.F. Snelson, Jr. 1984. Population structure, reproduction and laboratory behavior of the introduced Belonesox belizanus (Poeciliidae) in Florida. Environmental Biology of Fishes 10:89-100.

USFWS. 2011. U.S. Fish and Wildlife National Wildlife Refuge System Invasive Species Survey Information. http://www.nwrinvasives.com/index.asp. Accessed on 7/6/2011

Wischnath, L. 1993. Atlas of livebearers of the world. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ. 336 pp.

Other Resources:
Belonesox belizanus pike killifish - Texas State University San Marcos

Pike killifish - Florida Museum of Natural History

US Fish and Wildlife Service Ecological Risk Screening Summary for Belonesox belizanus

Author: Pamela J. Schofield, Leo Nico, and Matt Neilson

Peer Review Date: 4/17/2013

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.