Picture by Chad Thomas, Texas State University-San Marcos

Lepisosteus platostomus

shortnose gar

Type Locality

Ohio River (Rafinesque 1820).

Etymology/Derivation of Scientific Name

Synonymy

Lepisosteus platostomus Rafinesque 1820:72.

Characters

Maximum size: 830 mm (32.7 in) TL (Page and Burr 1991).

Coloration:

Counts: 59-63 lateral line scales; 50-54 predorsal scales; 38-44 scale rows around body (Hubbs et al. 2008).

Mouth position: Terminal (Goldstein and Simon 1999).

Body shape:  Scales ganoid; tail abbreviate-heterocercal (vertebrae moving into dorsal portion of fin).  Large canine teeth in one row on each side of upper jaw. Snout short and blunt, its least width goes about 5 to 7 times in snout length; snout less than two-thirds of head length (Hubbs et al. 2008).

External morphology:

Morphology: Large teeth in upper jaw in one row on each side (Hubbs et al. 2008).

Distribution (Native and Introduced)

U.S. distribution: Ranges throughout the Mississippi River drainage (Hubbs et al. 2008).

Texas distribution: Inhabits the Red River basin below Lake Texoma (Hubbs et al. 2008).

Abundance/Conservation status (Federal, State, NGO)

Currently Stable (Warren et al. 2008) in the southern United States.

Habitat Associations

Macrohabitat: Prefers low gradient, slowly flowing streams, oxbow lakes and backwater areas (Lee 1980; Hubbs et al. 2008).

Mesohabitat: Common in quiet, unvegetated, often backwater areas of rivers, and in lakes and oxbows (Lee 1980); more tolerant of turbidity than other species of gar.

Biology

Spawning season: In northern part of range, spawning occurs from May to early July in water 19-24°C, 66.2-75.2°F (Lee 1980).

Spawning habitat: No information at this time.

Spawning behavior: Nonguarder; open substratum spawner; phytophil – obligatory plant spawner with adhesive egg envelopes that stick to submerged live or dead plants (Simon 1999). Free embryos hatch late and possess cement glands; larvae possess extremely well developed embryonic respiratory structures and have no photophobic reaction (Balon 1981; Simon 1999).

Fecundity: No information at this time.

Age at maturation:  3 years (Lee 1980).

Migration:  No information at this time

Growth and Population structure:  Growth is rapid (Lee 1980).

Longevity: 20 years, in captivity (Lee 1980).

Food habits: Goldstein and Simon (1999) listed first and second level trophic classifications as carnivore and whole body, respectively; trophic mode – ambush; main food items included: crayfish, perch, and sunfish (in Iowa; Potter 1923); emerging knats and mayflies (in Illinois; Richardson 1913); common carp (in South Dakota; Shields 1957).

Phylogeny and morphologically similar fishes

See descriptions for L. oculatus (spotted gar), L. osseus (longnose gar), and Atractosteus spatula (alligator gar).

Host Records

 No information at this time.

Commercial or Environmental Importance

No information at this time.

References

Balon, E.K. 1981. Additions and amendments to the classification of reproductive styles in fishes. Environmental Biology of Fishes 6(3/4):377-389.

Goldstein, R.M., and T.P. Simon. 1999. Toward a united definition of guild structure for feeding ecology of North American freshwater fishes. pp. 123-202 in T.P. Simon, editor. Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press, Boca Raton, Florida. 671 pp.

Hubbs, C., R.J. Edwards, and G.P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science, Supplement, 2^nd edition 43(4):1-87.

Lee, D.S. 1980. Lepisosteus platostomus (Rafinesque), Shortnose gar. pp. 50 in D. S. Lee et al., Atlas of North American Freshwater Fishes. N. C. State Mus. Nat. Hist., Raleigh, i-r+854 pp.

Page, L. M. & B. M. Burr.  1991.  A field guide to freshwater fishes of North America north of Mexico.  Houghton Mifflin Company, Boston, Massachusetts. 432 pp.

Potter, G.E. 1923. Food of the short-nose gar-pike (Lepidosteus platystomus) in Lake Okoboji, Iowa. Proc. Iowa Acad. Sci. 30:167-170.

Rafinesque, C.S. 1820. Ichthyologia Ohiensis, or natural history of the fishes inhabiting the River Ohio and its tributary streams, preceded by a physical description of the Ohio and its branches. W.G. Hunt, Lexington, Kentucky. 

Richardson, R.E. 1913. Observations on the breeding habits of fishes at Havana, Illinois, 1910 and 1911. Bulletin of the Illinois State Laboratory of Natural History 9:405-416.

Riggs, C.D., and G.A. Moore. 1960. Growth of young gar (Lepisosteus) in aquaria. Proceedings of the Oklahoma Academy of Science 40:44-46.

Simon, T. P. 1999. Assessment of Balon’s reproductive guilds with application to Midwestern North American Freshwater Fishes, pp. 97-121. In: Simon, T.L. (ed.). Assessing the sustainability and biological integrity of water resources using fish communities. CRC Press. Boca Raton, Florida. 671 pp.

Suttkus, R.D. 1963. Order Lepisostei. Vol. 1(3):61-88. Memoir, Sears Foundation of Marine Research, Yale University, New Haven, Connecticut.

Warren, M.L., Jr., B.M. Burr, S.J. Walsh, H.L. Bart, Jr., R.C. Cashner, D.A. Etnier, B.J. Freeman, B.R. Kuhajda, R.L. Mayden, H.W. Robison, S.T. Ross, and W.C. Starnes. 2000. Diversity, Distribution, and Conservation status of the native freshwater fishes of the southern United States. Fisheries 25(10):7-29.

Wiley, E.O. 1976. The phylogeny and biogeography of fossil and recent gars (Actinopterygii: Lepisosteidae). University of Kansas Museum of Natural History, Miscellaneous Publ. 64:1-111.