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.

Ictiobus bubalus
Ictiobus bubalus
(Smallmouth Buffalo)
Native Transplant
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Ictiobus bubalus (Rafinesque, 1818)

Common name: Smallmouth Buffalo

Taxonomy: available through www.itis.govITIS logo

Identification: The body of Smallmouth Buffalo (Ictiobus bubalus) is deep and highly compressed. Fins are slate brown in color, the back bronze or slate olive, and sides bronze. Colors lighten with age. The snout is blunt with a small, ventral horizontal mouth. Inside the mouth there are 180-190 small fragile teeth per arch. The dorsal fin of Smallmouth Buffalo is sickle shaped with 26-31 rays. Anal fins have approximately 9 2101 rays and pelvic fins 9-11 rays. Sexes can be distinguished by the longest dorsal ray which is significantly larger in females (Becker 1983). Common hybridization among buffalo species has caused difficulty in identifying individual species (Dahline 2014).

Size: 78 cm.

Native Range: Lake Michigan drainage and Mississippi River basin from Pennsylvania and Michigan to Montana and south to Gulf of Mexico; Gulf Slope drainages from Mobile Bay, Alabama, to Rio Grande, Texas and New Mexico. Also in 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 Ictiobus bubalus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AZ191820173Lower Colorado Region; Lower Salt; Moenkopi Wash
CA197919791California Region
NY201420141Lake Erie
NC198620179Lower Pee Dee; Nolichucky; Rocky; Upper Catawba; Upper French Broad; Upper Neuse; Upper Pee Dee; Upper Pee Dee; Upper Yadkin
OH198420173Cedar-Portage; Chautauqua-Conneaut; Lake Erie
OK196220038Deep Fork; Lower Beaver; Lower Canadian; Lower Canadian-Deer; Lower Canadian-Walnut; Lower Cimarron-Eagle Chief; Lower North Canadian; Middle North Canadian
SC198620098Carolina Coastal-Sampit; Lower Broad; Lower Catawba; Lower Pee Dee; Santee; Upper Broad; Upper Catawba; Wateree
TX197420176Cibolo-Red Light; Denton; Hubbard; Lower West Fork Trinity; Terlingua; Upper West Fork Trinity
WI196519652Flambeau; Ontonagon

Table last updated 1/23/2021

† Populations may not be currently present.

Ecology: The Smallmouth Buffalo is known to be found in faster flowing waters than its relatives the Bigmouth Buffalo and Black Buffalo. Where the three species coexist the Smallmouth Buffalo and Black Buffalo are observed to prefer deeper water and the Smallmouth Buffalo exhibits a preference for fine substrates (Becker 1983).

The Smallmouth Buffalo begins spawning in April to early June at temperatures of 15.6-18.3°C (Becker 1983). 18,000-500,000 adhesive eggs per female are randomly disturbed over any substrate.  Smallmouth Buffalo have a possible preference for spawning over submerged vegetation (Etnier and Starnes 1993). Spawning has been observed to be the most successful in years when water levels rise during the spring to flood marshes or low-lying meadows (Becker 1983).

The diet of Ictiobus bubalus under one year old is composed of copepods and cladocerans. Other food sources for young include algae, duckweed, protozoans, rotifers, insect larvae, and insect eggs. When mature, Ictiobus bubalus is an opportunistic feeder, feeding on organisms that are most abundant. The primary source of food depends on where the species is found (Becker 1983).

Means of Introduction: Accidental introduction in Arizona in 1918 with bigmouth buffalo I. cyprinellus (Minckley 1973; Rinne 1994); unknown means in California, and South Carolina. Likely stocked in North Carolina (Leach 1921, 1923). Stocked in Wisconsin during fish rescue operations from the Mississippi River in the 1930s (Becker 1983).

Status: Unknown in most sites in Arizona. Established in Apache Lake, Arizona, and in North and South Carolina. Extirpated in California. Unknown in Wisconsin; still present in the 1960s (Becker 1983). Native to portions of the Great Lakes basin, but considered nonindegenous in other locations.

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: In the early 1900s all three species of buffalofishes were stocked; I. bubalus, I. cyprinellus, and I. velifer (Leach 1921, 1923). However, when the stockings were reported they were lumped together as "buffalofish" and it is not possible to determine which species were planted. Stocking of buffalofishes occurred outside their native ranges in Lake Erie in Ohio, the Pee Dee and Catawba drainages in North Carolina, and in unknown locations in Massachusetts (Leach 1921, 1923).

References: (click for full references)

Anonymous. 1992.  1991 Angler Recognition Entries - Freshwater. Texas Parks & Wildlife News.  Austin, TX.

Becker, G. C. 1983. Fishes of Wisconsin. University of Wisconsin Press, Madison, WI.

Dahline, C. 2014. ADW: Ictiobus niger. http://animaldiversity.org/accounts/Ictiobus_niger/. Accessed on 08/22/2017.

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

Frimodt, C. 1995. Multilingual illustrated guide to the world's commercial coldwater fish. Fishing News Books, Osney Mead, Oxford, England.

Hocutt, C. H., R. E. Jenkins, and J.R. Stauffer, Jr. 1986. Zoogeography of the fishes of the central Appalachians and central Atlantic Coastal Plain. Pages 161--212 in C. H. Hocutt, and E. O. Wiley, editors. The Zoogeography of North American Freshwater Fishes. John Wiley and Sons, New York, NY.

Hubbs, C., R. J. Edwards, and G. P. Garrett. 1991. An annotated checklist of freshwater fishes of Texas, with key to identification of species. Texas Journal of Science, Supplement 43(4):1-56.

Hubbs, C. L., W. I. Follett, and L. J. Dempster. 1979. List of the fishes of California. California Academy Science Occasional Papers 133. 51 pp.

Johnson, D.W. and W.L. Minckley. 1969. Natural Hybridization in Buffalofishes, Genus Ictiobus. Copeia 1969(1):198-200.

Leach, G.C. 1921. Distribution of fish and fish eggs during the fiscal year 1919. Appendix I to the Report of the U.S. Commissioner of Fisheries for 1919. Bureau of Fisheries Document No. 878. Goverment Printing Office, Washington, DC.

Leach, G.C. 1923. Propagation and distribution of food fishes, 1922. Report of the division of fish culture for the fiscal year 1922. Appendix XVII to the Report of the U.S. Commissioner of Fisheries for 1922. Bureau of Fisheries Document No. 941. Government Printing Office, Washington, DC.

Martin, R.E., S.I. Auerbach, and D.J. Nelson. 1964. Growth and Movement of Smallmouth Buffalo, Ictiobus bubalus (Rafinesque), In Watts Bar Reservoir, Tennessee. Unpublished Ph.D. dissertation. The University of Tennessee, Oak Ridge, TN.

Mathews, W. J., and F. R. Gelwick.  1990. Fishes of Crutcho Creek and the North Canadian River in central Oklahoma: effects of urbanization.  Southwestern Naturalist 35(4):403-410.

Menhinick, E. F. 1991. The freshwater fishes of North Carolina. North Carolina Wildlife Resources Commission. 227 pp.

Minckley, W. L. 1973. Fishes of Arizona. Arizona Fish and Game Department. Sims Printing Company, Inc., Phoenix, AZ.

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.

Rohde, F. C., R. G. Arndt, J. W. Foltz, and J. M. Quattro. 2009. Freshwater Fishes of South Carolina. University of South Carolina Press, SC. 430 pp.

Rhode, F. C., R. G. Arndt, D. G. Lindquist, and J. F. Parnell. 1994. Freshwater Fishes of the Carolinas, Virginia, Maryland, and Delaware. University of Carolina Press, Chappel Hill, NC. 222 pp.

Rinne, J. N. 1994. The effects of introduced fishes on native fishes: Arizona, southwestern United States. World fisheries congress, May 1992, Athens, Greece.

FishBase Summary

Author: Fuller, P. and K. Hopper

Revision Date: 5/14/2020

Peer Review Date: 9/10/2011

Citation Information:
Fuller, P. and K. Hopper, 2021, Ictiobus bubalus (Rafinesque, 1818): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=361, Revision Date: 5/14/2020, Peer Review Date: 9/10/2011, Access Date: 1/24/2021

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. [2021]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [1/24/2021].

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