Alligator Gar
Atractosteus spatula
About This Fish

The Alligator Gar is found in Gulf Coast drainages from Mexico to Florida and extending north to Illinois and Ohio. They are found in pools and backwaters of rivers and bayous. The largest freshwater fish of Eastern North America, Alligator Gars reach 12 feet in length! As the common name suggests, they have a short and broad snout similar to an alligator. They are the only gar with two rows of large teeth on their upper jaw.


Daugherty, D.J., J.W. Schlechte, and D.L. McDonald. 2018. Alligator Gars in Texas coastal bays: long term trends and environmental influences. Transactions of the American Fisheries Society, 147(4), 653-664.

McDonald, D.L., J.W. Schlechte, and D.J. Daugherty. 2018. Comparison of two biometric methods for nonlethal sex determination of Alligator Gars. Transactions of the American Fisheries Society, 147(4), 711-715

Fleming, P.B., D.J. Daugherty, N.G. Smith, and R.K. Betsill. 2018. Efficacy of low cost, side scan sonar for surveying Alligator Gars. Transactions of the American Fisheries Society, 147(4), 696-703.

Robertson, C.R., K. Aziz, D.L. Buckmeier, N.G. Smith, and N. Raphelt. 2018. Development of a flow specific floodplain inundation model to assess Alligator Gar recruitment success. Transactions of the American Fisheries Society, 147(4), 674-686.

Smith, N.G., D.J. Daugherty, J.W. Schlechte, and D.L. Buckmeier. 2018. Modeling the responses of Alligator Gar populations to harvest under various length based regulations: implications for conservation and management. Transactions of the American Fisheries Society, 147(4), 665-673.

van der Most, M., and P.F. Hudson. 2018. The influence of floodplain geomorphology and hydrologic connectivity on alligator gar (Atractosteus spatula) habitat along the embanked floodplain of the Lower Mississippi River. Geomorphology, 302, 62-75.

Allen, P.J., A. Haukenes, and S.E. Lochmann. 2017. Similarity of osmoregulatory capacity in coastal and inland alligator gar. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 209, 16-24.

Bohn, S., B.R. Kreiser, D.J. Daugherty, and K.A. Bodine. 2017. Natural hybridization of lepisosteids: implications for managing the Alligator Gar. North American Journal of Fisheries Management, 37(2), 405-413.

Buckmeier, D.L., N.G. Smith, D.J. Daugherty, and D.L. Bennett. 2017. Reproductive ecology of Alligator Gar: identification of environmental drivers of recruitment success. Journal of the Southeastern Association of Fish and Wildlife Agencies, 4, 8-17.

Daugherty, D.J., K.L. Pangle, W. Karel, F. Baker, C.R. Robertson, D.L. Buckmeier, N.G. Smith, and N. Boyd. 2017. Population structure of Alligator Gar in a Gulf Coast river: insights from otolith microchemistry and genetic analyses. North American Journal of Fisheries Management, 37(2), 337-348.

Kluender, E.R., R. Adams, and L. Lewis. 2017. Seasonal habitat use of alligator gar in a river–floodplain ecosystem at multiple spatial scales. Ecology of freshwater fish, 26(2), 233-246."

Sherman, V.R., H. Quan, W. Yang, R.O. Ritchie, and M.A. Meyers. 2017. A comparative study of piscine defense: The scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula. Journal of the mechanical behavior of biomedical materials, 73, 1-16.

Fernando, A.V., S.E. Lochmann, and A.H. Haukenes. 2016. Critical thermal maxima of juvenile alligator gar (Atractosteus spatula, Lacépède, 1803) from three Mississippi drainage populations acclimated to three temperatures. Journal of Applied Ichthyology, 32(4), 701-705.

Long, J.M., and R.A. Snow. 2016. Ontogenetic development of otoliths in alligator gar. Transactions of the American Fisheries Society, 145(3), 537-544.

Omar-Ali, A., W. Baumgartner, P.J. Allen, and L. Petrie-Hanson. 2016. Fine Structure of the Gas Bladder of Alligator Gar, Atractosteus spatula. International Journal of Toxicology and Environmental Science, 1, 8.

Schlechte, J.W., K.A. Bodine, D.J. Daugherty, and G.R. Binion. 2016. Size selectivity of multifilament gill nets for sampling Alligator Gar: modeling the effects on population metrics. North American Journal of Fisheries Management, 36(3), 630-638.

Sherman, V.R., N.A. Yaraghi, D. Kisailus, and M.A. Meyers. 2016. Microstructural and geometric influences in the protective scales of Atractosteus spatula. Journal of the Royal Society Interface, 13(125), 20160595.

Snow, R.A., and J.M. Long. 2016. Effects of a growth check on daily age estimates of age-0 Alligator Gar. Journal of the Southeastern Association of Fish and Wildlife Agencies, 3, 6-10.

Snow, R.A., and J.M. Long. 2016. Estimating Spawning Times of Alligator Gar (Atractosteus spatula) in Lake Texoma, Oklahoma. In Proceedings of the Oklahoma Academy of Science (Vol. 95).

Bennett, D.L., R.A. Ott, and C.C. Bonds. 2015. Surveys of Texas bow anglers, with implications for managing Alligator Gar. Journal of the Southeastern Association of Fish and Wildlife Agencies, 2, 8-14.

Binion, G.R., D.J. Daugherty, and K.A. Bodine. 2015. Population dynamics of alligator gar in Choke Canyon Reservoir, Texas: implications for management. Journal of the Southeastern Association of Fish and Wildlife Agencies, 2, 57-63.

Bodine, K.A., D.J. Daugherty, J.W. Schlechte, and G.R. Binion. 2015. A strategy for increasing gill-net catch rates and minimizing sampling mortality of Alligator Gars. North American Journal of Fisheries Management, 35(3), 611-615.

Castillo, S., K. Bollfrass, R. Mendoza, Q. Fontenot, J.P. Lazo, C. Aguilera, and A. Ferrara. 2015. Stimulatory effect of thyroid hormones improves larval development and reproductive performance in alligator gar (Atractosteus spatula) and spotted gar (Lepisosteus oculatus). Aquaculture research, 46(9), 2079-2091.

Felterman, M.A. 2015. Population dynamics, reproductive biology, and diet of alligator gar Atractosteus spatula in Terrebonne Estuary and Rockefeller Wildlife Refuge (Doctoral dissertation, Master’s Thesis. Nicholls State University, Thibodaux, Louisiana).

González, C.A., J. Cruz, and R.M. Alfaro. 2015. Physiological response of alligator gar juveniles (Atractosteus spatula) exposed to sub-lethal doses of pollutants. Fish physiology and biochemistry, 41(4), 1015-1027.

Hodo, W.D. 2015. Investigation of the inherent chemical, structural, and mechanical attributes of bio-engineered composites found in nature: Alligator gar’s exoskeleton fish scales.

Omar-Ali, A., C. Hohn, P.J. Allen, J. Rodriguez, and L. Petrie-Hanson. 2015. Tissue PAH, blood cell and tissue changes following exposure to water accommodated fractions of crude oil in alligator gar, Atractosteus spatula. Marine environmental research, 108, 33-44.

Richardson, B.M. 2015. A dietary comparison of the reintroduced alligator gar atractosteus spatula and three sympatric Gar relatives (family: Lepisosteidae) in the Clarks River, Kentucky (Doctoral dissertation, Murray State University).

Allen, Y.C., K.M. Kimmel, and G.C. Constant. 2014. Using remote sensing to assess Alligator Gar spawning habitat suitability in the lower Mississippi River. US Fish and Wildlife Service, Baton Rouge Fish and Wildlife Conservation Office, Baton Rouge, Louisiana.

Allison, P.G., R.I. Rodriguez, R.D. Moser, B.A. Williams, A.R. Poda, J.M. Seiter, B.J. Lafferety, A.J. Kennedy, and M.Q. Chandler. 2014. Characterization of multi-layered fish scales (Atractosteus spatula) using nanoindentation, X-ray CT, FTIR, and SEM. JoVE (Journal of Visualized Experiments), (89), e51535.

Sakaris, P.C., Buckmeier, D.L., and N.G. Smith. 2014. Validation of daily ring deposition in the otoliths of age-0 Alligator Gar. North American journal of fisheries management, 34(6), 1140-1144.

Schwarz, D.E., and P.J. Allen. 2014. Effects of salinity on growth and ion regulation of juvenile alligator gar Atractosteus spatula. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 169, 44-50.

Snow, R.A. 2014. Life history of juvenile alligator gar (Atractosteus spatula) in Oklahoma (Doctoral dissertation, Oklahoma State University)

Allison, P.G., M.Q. Chandler, R.I. Rodriguez, B.A. Williams, R.D. Moser, C.A. Weiss Jr, A.R. Poda, B.J. Lafferty, A.J. Kennedy, J.M. Seiter, and W.D. Hodo. 2013. Mechanical properties and structure of the biological multilayered material system, Atractosteus spatula scales. Acta biomaterialia, 9(2), 5289-5296.

Bohn, S., E. Barraza, C. McMahan, W. Matamoros, and B. Kreiser. 2013. Cross amplification of microsatellite loci developed for Atractosteus spatula in Atractosteus tropicus. Revista Mexicana de Biodiversidad, 84(4), 1349-1351.

Buckmeier, D.L., N.G. Smith, and D.J. Daugherty. 2013. Alligator Gar movement and macrohabitat use in the lower Trinity River, Texas. Transactions of the American Fisheries Society, 142(4), 1025-1035.

McDonald, D.L., J.D. Anderson, C. Hurley, B.W. Bumguardner, and C.R. Robertson. 2013. Sexual Dimorphism in Alligator Gar. North American journal of fisheries management, 33(4), 811-816.

Militello, J. 2013. Juvenile alligator gar Atractosteus spatula home ranges, spatiotemporal movement patterns and habitat use in the Clarks river, Western Kentucky (Doctoral dissertation, Murray State University).

Solomon, L.E., Q.E. Phelps, D.P. Herzog, C.J. Kennedy, and M.S. Taylor. 2013. Juvenile Alligator Gar movement patterns in a disconnected floodplain habitat in southeast Missouri. The American Midland Naturalist, 336-344.

Yang, W., B. Gludovatz, E.A. Zimmermann, H.A. Bale, R.O. Ritchie, and M.A. Meyers. 2013. Structure and fracture resistance of alligator gar (Atractosteus spatula) armored fish scales. Acta biomaterialia, 9(4), 5876-5889.

Buckmeier, D.L., N.G. Smith, and K.S. Reeves. 2012. Utility of Alligator Gar age estimates from otoliths, pectoral fin rays, and scales. Transactions of the American Fisheries Society, 141(6), 1510-1519.

Mendoza, R., O. Santillán, A. Revol, C. Aguilera, and J. Cruz. 2012. Alligator gar (Atractosteus spatula, Lacépède 1803) vitellogenin: purification, characterization and establishment of an enzyme linked immunosorbent assay. Aquaculture Research, 43(5), 649-661.

Clay, T.A., M.D. Suchy, A.M. Ferrara, Q.C. Fontenot, and W. Lorio. 2011. Early growth and survival of larval alligator gar, Atractosteus spatula, reared on artificial floating feed with or without a live Artemia spp. supplement. Journal of the World Aquaculture Society, 42(3), 412-416.

Kluender, E.R. 2011. Seasonal habitat use of a leviathan, alligator gar, at multiple spatial scales in a river-floodplain ecosystem (Doctoral dissertation, University of Central Arkansas. Department of Biology.

Perschbacher, P.W. 2011. Effects of structure, forage, and stocking density on juvenile production of alligator gars in outdoor pools. North American Journal of Aquaculture, 73(1), 21-23.

Salnikov, V.B. 2010. First finding of gar Atractosteus sp.(Actinopterygii, Lepisosteiformes, Lepisosteidae) in the Caspian Sea near the coast of Turkmenistan. Russian Journal of Biological Invasions, 1(1), 17-20.

Clay, T.A. 2009. Growth, survival, and cannibalism rates of alligator gar Atractosteus spatula in recirculating aquaculture systems (Doctoral dissertation, Nicholls State University).

DiBenedetto, K.C. 2009. Life history characteristics of alligator gar, Atractosteus spatuala, in the Bayou DuLarge area of southcentral Louisiana.

Inebnit III, T.E. 2009. Aspects of the reproductive and juvenile ecology of Alligator Gar in the Fourche LaFave River, Arkansas. Master's thesis. University of Central Arkansas, Conway

Moyer, G.R., B.L. Sloss, B.R. Kreiser, and K.A. Feldheim. 2009. Isolation and characterization of microsatellite loci for alligator gar (Atractosteus spatula) and their variability in two other species (Lepisosteus oculatus and L. osseus) of Lepisosteidae. Molecular ecology resources, 9(3), 963-966.

Suchy, M.D. 2009. Effects of Salinity on Growth and Survival of Larval and Juvenile Alligator Gar Atractosteus spatula, and on Plasma Osmolality of Non-teleost Actinoperygiian Fishes (Doctoral dissertation, Nicholls State University).

Brinkman, E.L. 2008. Contributions to the Life History of Alligator Gar, Atractosteus Spatula (Lacpde), in Oklahoma (Doctoral dissertation, Oklahoma State University).

Herrington, S.J., K.N. Hettiger, E.J. Heist, and D.B. Keeney. 2008. Hybridization between longnose and alligator gars in captivity, with comments on possible gar hybridization in nature. Transactions of the American Fisheries Society, 137(1), 158-164.

Layher, W. G., A.O. Layher, B.S. Crabb, and M. Spurlock. 2008. Literature survey, status in states of historic occurrence, and field investigations into the life history of Alligator Gar in the Ouachita River, Arkansas. Layher BioLogics RTEC, Taylor & Francis, Arkansas.

Mendoza, R., C. Aguilera, L. Carreon, J. Montemayor, and M. González. 2008. Weaning of alligator gar (Atractosteus spatula) larvae to artificial diets. Aquaculture nutrition, 14(3), 223-231.

Mendoza Alfaro, R., C.A. González, and A.M. Ferrara. 2008. Gar biology and culture: status and prospects. Aquaculture Research, 39(7), 748-763.

Robertson, C.R., S.C. Zeug, and K.O. Winemiller. 2008. Associations between hydrological connectivity and resource partitioning among sympatric gar species (Lepisosteidae) in a Texas river and associated oxbows. Ecology of Freshwater Fish, 17(1), 119-129.

Boudreaux, P.J., A.M. Ferrara, and Q.C. Fontenot. 2007. Acute toxicity of ammonia to spotted gar, Lepisosteus oculatus, alligator gar, Atractosteus spatula, and paddlefish, Polyodon spathula. Journal of the World Aquaculture Society, 38(2), 322-325.

O’Connell, M.T., T.D. Shepherd, A.M. O’Connell, and R.A. Myers. 2007. Long-term declines in two apex predators, bull sharks (Carcharhinus leucas) and alligator gar (Atractosteus spatula), in lake pontchartrain, an oligohaline estuary in southeastern Louisiana. Estuaries and Coasts, 30(4), 567-574.

Tkach, V.V., E.J. Strand, and L. Froese. 2008. Macroderoides texanus n. sp.(Digenea: Macroderoididae) from alligator gar, Atractosteus spatula in Texas. Parasitology research, 104(1), 27-33.

Aguilera, G.C., R. Mendoza, G. Márquez, and I. Iracheta. 2005. Alligator gar (Atractosteus spatula) larval development and early conditioning to artificial diets. Memories of Aquaculture America New Orleans, Lousiana, EUA, 6.

Revol, A., Rodríguez, M. D. L. G., V.H. Montenegro, C. Aguilera, H.B. Saldaña, and R. Mendoza. 2005. Cloning of the growth hormone cDNA of alligator gar Atractosteus spatula and its expression through larval development. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 140(4), 423-429.

Todd, R.M. 2005. Tennessee alligator gar management plan. Tennessee Wildlife Resources Agency Fisheries Management Division, 1-14

Aguilera, C., R. Mendoza, G. Rodríguez, and G. Márquez. 2002. Morphological description of alligator gar and tropical gar larvae, with an emphasis on growth indicators. Transactions of the American Fisheries Society, 131(5), 899-909.;2

Mendoza, R., C. Aguilera, G. Rodríguez, M. González, and R. Castro. 2002. Morphophysiological studies on alligator gar (Atractosteus spatula) larval development as a basis for their culture and repopulation of their natural habitats. Reviews in Fish Biology and Fisheries, 12(2-3), 133-142.

Mendoza, R., C. Aguilera, J. Montemayor, A. Revol and J. Holt. 2002. Studies on the physiology of Atractosteus spatula larval development and its applications to early weaning onto artificial diets. Avances en nutrición acuícola VI. Memorias del VI Simposium Internacional de Nutrición Acuícola, 3, 197-226.

de León, F.J.G., L. González-García, J.M. Herrera-Castillo, K.O. Winemiller, and A. Banda-Valdés. 2001. Ecology of the alligator gar, Atractosteus spatula, in the Vicente Guerrero Reservoir, Tamaulipas, Mexico. The Southwestern Naturalist, 151-157.

Ferrara, A.M., and E.R. Irwin. 2001. A standardized procedure for internal sex identification in Lepisosteidae. North American Journal of Fisheries Management, 21(4), 956-961.;2

Poly, W.J. 2001. Distribution of the Alligator Gar, Atractosteus spatula (Lacépède, 1803), in Illinois. Transactions of the Illinois State Academy of Science, 94, 185-190.

Dores, R.M., H. Keller, Y. White, L.E. Marra, and J.H. Youson. 1994. Detection of N-acetylated forms of α-MSH and β-endorphin in the intermediate pituitary of the holostean fishes, Lepisosteus spatula, Lepisosteus osseus, and Amia calva. Peptides, 15(3), 483-487.

Gilbert, C.R. 1992. Alligator gar, Atractosteus spatula. Rare and endangered biota of Florida, 2.

Scarnecchia, D.L. 1992. A reappraisal of gars and bowfins in fishery management. Fisheries, 17(5), 6-12.;2

Sherwood, N.M., S. Doroshov, and V. Lance. 1991. Gonadotropin-releasing hormone (GnRH) in bony fish that are phylogenetically ancient: reedfish (Calamoichthys calabaricus), sturgeon (Acipenser transmontanus), and alligator gar (Lepisosteus spatula). General and comparative endocrinology, 84(1), 44-57.

Joss, J.M., R.M. Dores, J.W. Crim, and M. Beshaw. 1990. Immunocytochemical location of pituitary cells containing ACTH, α-MSH, and β-endorphin in Acipenser transmontanus, Lepisosteus spatula, and Amia calva. General and comparative endocrinology, 78(3), 459-468.

Pollock, H.G., J.R. Kimmel, K.E. Ebner, J.W. Hamilton, J.B. Rouse, V. Lance, and A.B. Rawitch. 1988. Isolation of alligator gar (Lepisosteus spatula) glucagon, oxyntomodulin, and glucagon-like peptide: amino acid sequences of oxyntomodulin and glucagon-like peptide. General and comparative endocrinology, 69(1), 133-140.

Pollock, H.G., J.R. Kimmel, J.W. Hamilton, J.B. Rouse, K.E. Ebner, V. Lance, and A.B. Rawitch. 1987. Isolation and structures of alligator gar (Lepisosteus spatula) insulin and pancreatic polypeptide. General and comparative endocrinology, 67(3), 375-382.

Goodger, W.P., and T.A. Burns. 1980. The cardiotoxic effects of alligator gar (Lepisosteus spatula) roe on the isolated turtle heart. Toxicon, 18(4), 489-494.

Echelle, A.A., and C.D. Riggs. 1972. Aspects of the early life history of gars (Lepisosteus) in Lake Texoma. Transactions of the American Fisheries Society, 101(1), 106-112.

May, E. B., & Echelle, A.A. 1968. Young-of-year alligator gar in Lake Texoma, Oklahoma. Copeia, 1968(3), 629-630.

Goodyear, C.P. 1967. Feeding habits of three species of gars, Lepisosteus, along the Mississippi Gulf Coast. Transactions of the American Fisheries Society, 96(3), 297-300.

Winston, W.D. 1967. Effects of temperature and light on the rate of aerial breathing of the alligator gar, Lepisosteus spatula (Doctoral dissertation, University of Oklahoma).