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.

Atractosteus spatula
Atractosteus spatula
(Alligator Gar)
Native Transplant

Copyright Info
Atractosteus spatula (Lacep├Ęde, 1803)

Common name: Alligator Gar

Taxonomy: available through www.itis.govITIS logo

Identification: Suttkus (1963); Page and Burr (1991); Etnier and Starnes (1993). Synonym Lepisosteus spatula.

Size: 3 m.

Native Range: Mississippi River basin from southwestern Ohio and southern Illinois south to Gulf of Mexico; Gulf Coastal Plain from Econfina River, Florida, to Veracruz, Mexico (Page and Burr 1991).

Native range data for this species provided in part by NatureServe NS logo
Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Atractosteus spatula are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
CA199120132Los Angeles; San Joaquin Delta
FL197019701Daytona-St. Augustine
KS202120211Middle Neosho
TX195620194East Galveston Bay; Lower Trinity-Tehuacana; Middle Guadalupe; Sulphur Headwaters

Table last updated 7/16/2024

† Populations may not be currently present.

Ecology: The Alligator Gar lives in coastal estuaries and major coastal rivers (Mettee et al. 1996). It is found in fresh, brackish, and occasionally salt water (Boschung and Mayden, 2004). The Alligator Gar is the largest of the gars, reaching nearly 10 feet in length (Ross, 2001). It feeds primarily on fishes, but will also eat crabs, carrion, and birds. This species spawns in late spring; the eggs are toxic (Ross, 2001).

Means of Introduction: The introduction of the California individual was attributed to release by an aquarium hobbyist (Raquel 1992). It is probably that the South Carolina specimen was also an aquarium release.  This species is becoming fairly common in the aquarium trade (P. Fuller, pers. observation).

Status: Reported in California and South Carolina.

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: The California specimen was recorded in water with a temperature of 25°C and a salinity of approximately 4.5 ppt (Raquel 1992).

References: (click for full references)

Boschung, H.T., Jr. and R.L. Mayden. 2004. Fishes of Alabama. Smithsonian Books, Washington. 736 pp.

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

Mettee, M.F., P.E. O'Neil, and J.M. Pierson. 1996. Fishes of Alabama and the Mobile Basin. Oxmoor House, Inc, Birmingham, AL. 820 pp.

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.

Raquel, P. F. 1992. Record of the alligator gar (Lepisosteus spatula) from the Sacramento-San Joaquin Delta. California Fish and Game 78(4):169-171.

Ross, S. 2001. The Inland Fishes of Mississippi. University Press of Mississippi. Jackson, Mississippi.

Suttkus, R.D. 1963. Order Lepisostei in: Bigelow et al. (eds.) Fishes of the Western North Atlantis. Soft-rayed Bony Fishes, Vol. 1, pt. 3, Memoir. Sears Foundation of Marine Research, Yale University, New Haven, Connecticut. pp 61-88.

FishBase Summary

Author: Fuller, P.

Revision Date: 7/30/2019

Peer Review Date: 8/7/2013

Citation Information:
Fuller, P., 2024, Atractosteus spatula (Lacep├Ęde, 1803): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=755, Revision Date: 7/30/2019, Peer Review Date: 8/7/2013, Access Date: 7/16/2024

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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/16/2024].

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