Ictiobus bubalus (Rafinesque, 1818)

Common Name: Smallmouth Buffalo

Synonyms and Other Names:

Brett Billings, US Fish and Wildlife ServiceCopyright Info

Brett Billings, US Fish and Wildlife ServiceCopyright Info

Jonathan FreedmanCopyright Info

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).

Great Lakes Nonindigenous Occurrences: Specimens have been taken from the Big Lake and Island Lake region in Vilas County, Wisconsin (Becker 1963).

Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, 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.

Full list of USGS occurrences

State/ProvinceFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
NY201420141Lake Erie
OH198420173Cedar-Portage; Chautauqua-Conneaut; Lake Erie

Table last updated 6/13/2021

† 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.

Great Lakes Impacts: Current research on the environmental impact/effect of Ictiobus bubalus in the Great Lakes is inadequate to support proper assessment.

In Tennessee Smallmouth Buffalo were observed to be in direct competition with carp, however neither species was affected adversely (Martin et al. 1964).  Natural hybridization is common among Ictiobus spp. (Johnson and Minckley 1969).

There is little or no evidence to support that Ictiobus bubalus has significant socio-economic impacts in the Great Lakes.

There is little or no evidence to support that Ictiobus bubalus has significant beneficial impacts in the Great Lakes.

Smallmouth Buffalo are caught commercially with gill net and seine. In the Wisconsin waters of the Mississippi river the catch of four buffalo species averaged 269kg per year over a 11 year period. The proportion of Smallmouth Buffalo in this catch is unknown but believed to be a more valuable part of the catch (Becker 1983). Smallmouth Buffalo also show aquaculture potential (Frimodt 1995). The species is seldom caught by recreational fisherman (Becker 1983).

Management: Regulations
Ictiobus bubalus appears on the IL list of species approved for aquaculture.

Fishing is regulated by state laws. Check with local agencies for specific regulation and management practices.

Note: Check federal, state, and local regulations for the most up-to-date information.


There are no known methods of biological control for Ictiobus bubalus.


Physical control has not been studied specifically for Ictiobus bubalus.  General  methods of physical control for fish include accelerated water velocity, physical barriers, pressurized hot water/steam, hot water thermal barriers , removal of catch limits, reservoir drawdowns, traps, nets, electrofishing, and combinations of treatments (GLMRIS 2011, Meronek et al. 1996). Patrick et al. (1985) observed that air bubble curtains have been successful in deterring various species of fish—especially when used in conjunction with strobe lights.


Chemical piscicides antimycin A and rotenone are general piscicides, the use of which has not been studied on Ictiobus bubalus. These piscicides are toxic to other species and can cause non-target kills  (GLMRIS 2012).

Careful consideration should be taken with chemical methods to reduce impact to non-target species.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.

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.

Author: Fuller, P. and K. Hopper

Contributing Agencies:

Revision Date: 5/14/2020

Peer Review Date: 9/10/2011

Citation for this information:
Fuller, P. and K. Hopper, 2021, Ictiobus bubalus (Rafinesque, 1818): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?Species_ID=361, Revision Date: 5/14/2020, Peer Review Date: 9/10/2011, Access Date: 6/23/2021

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.