Common name: Shortnose Gar
available through www.itis.gov
Identification: Lepisosteus platostomus is a long, slender fish with rows of interlocking rhomboidal ganoid scales. It is brown or olive green along its back, which fades to yellowish sides and a whitish belly. The dorsal fin is located to the posterior, almost directly above the anal fin, and is close to the large caudal fin. Shortnose gar can be discerned from other gar species in that they lack the upper jaw of the alligator gar, the long snout of the longnose gar, and the markings of the spotted gar. For further identification details, see Suttkus (1963); Becker (1983); Page and Burr (1991); Etnier and Starnes (1993).
Size: 83 cm
Native Range: Mississippi River basin from south-central Ohio, northern Indiana and Wisconsin to Montana and south to northern Alabama and Louisiana (Page and Burr 1991).
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 Lepisosteus platostomus are found here.
Table last updated 2/27/2023
† Populations may not be currently present.
Ecology: This species prefers slow silty or clear-water rivers, wave-washed shoals of large lakes, quiet creek pools and river backwaters. It is usually found at the water surface, often near vegetation and submerged logs. Larvae attach to vegetation or debris, and adult fish spawn in shallow grassy sloughs (Becker 1983).
Shortnose gar typically spawn in the spring during April, May and June, when water temperatures are between 16 and 21 °C. Females scatter large, yellowish-green eggs in quiet, shallow water among submerged vegetation or other underwater structures. A sticky adhesive holds the eggs together in clumps where they hatch after eight to nine days. The eggs are poisonous to birds and mammals, including humans (Montana Field Guide, 2019). The young remain in the yolk sac for another week, where they feed on insect larvae and small crustaceans. Young gar typically lead solitary lives and sexual maturity is achieved around three years of age when the gar reaches about 15 in (380 mm) in length (Montana Field Guide, 2019).
The diet of the shortnose gar is primarily composed of fish, though crayfish and insects are also utilized (Brown 1971). Young gar are known to feed on small insects and zooplankton, with fish entering the diet when gar are 1.25 inches in length. Gar are known as fierce predators of smaller fish, using ambush as a primary hunting technique.
Gar have the ability to survive in environments with very little oxygen and especially turbid conditions because of their specialized gas bladder, which have the ability to function like a lung to extract and use oxygen from swallowed air in addition to regulating buoyancy (Montana Field Guide, 2019).
Means of Introduction: This species likely reached Lake Winnebago via the Wisconsin-Fox Canal, a canal connection from the Mississippi River basin to the Fox River in the Great Lakes basin (Priegel 1963).
Status: Established in Wisconsin (Becker 1983; Page and Burr 1991).
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.
References: (click for full references)
Becker, G.C. 1983. Fishes of Wisconsin. University of Wisconsin Press, Madison, WI. 1052 pp. Available: http://digital.library.wisc.edu/1711.dl/EcoNatRes.FishesWI
Clearwater, S.J., C.W. Hickey, and M.L. Martin. 2008. Overview of potential piscicides and molluscicides for controlling aquatic pest species in New Zealand. Science & Technical Publishing, New Zealand Department of Conservation, Wellington, New Zealand.
Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. The University of Tennessee Press, Knoxville, TN. 681 pp.
Evermann, B.W., and E.L. Goldsborough. 1902. Notes on the fishes and mollusks of Lake Chautauqua, New York. Report of U.S. Commission of Fish and Fisheries 27:169-175.
GLMRIS. 2012. Appendix C: Inventory of Available Controls for Aquatic Nuisance Species of Concern, Chicago Area Waterway System. U.S. Army Corps of Engineers.
Montana Field Guide. 2019. Shortnose Gar — Lepisosteus platostomus. Montana Natural Heritage Program and Montana Fish, Wildlife and Parks. Retrieved on May 10, 2019, from http://FieldGuide.mt.gov/speciesDetail.aspx?elcode=AFCBA01030
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.
Priegel, G.R. 1963. Dispersal of the shortnose gar, Lepisosteus platostomus, into the Great Lakes drainage. Transactions of the American Fisheries Society 92(2):178.
Scott, W.B., and E.J. Crossman. 1998. Freshwater Fishes of Canada. Galt House Publications Ltd., Ontario. 966 pp.
Suttkus, R.D. 1963. Order Lepisostei, pp. 61-88. in: Bigelow et al. (eds.) Fishes of the Western North Atlantic. Soft-rayed Bony Fishes, Vol. 1, pt. 3. Memoir, Sears Foundation of Marine Research, Yale University, New Haven, Connecticut.
Fuller, P., J. Larson, T.H. Makled, and A. Fusaro
Revision Date: 9/12/2019
Peer Review Date: 8/2/2013
Fuller, P., J. Larson, T.H. Makled, and A. Fusaro, 2023, Lepisosteus platostomus Rafinesque, 1820: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=757, Revision Date: 9/12/2019, Peer Review Date: 8/2/2013, Access Date: 3/27/2023
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.