Ictiobus bubalus
(Rafinesque, 1818)
Common Name:
Smallmouth Buffalo
Synonyms and Other Names:
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 9-10 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) as well as multiple locations in Lake Erie (Ohio State University Museum 2013) beginning in the 1980s. Introductions to the Great Lakes represent northward expansions of the native range.
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
Table last updated 12/14/2024
† 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).
Great Lakes Means of Introduction:
Ictiobus bubalus was stocked in Wisconsin during fish rescue operations from the Mississippi River in the 1930s (Becker 1983). Stocking of buffalofishes (unidentified species, but potentially including I. bubalus) also occurred in Lake Erie in Ohio (Leach 1921, 1923).
Great Lakes Status:
Overwintering, reproducing and spreading in Lake Erie.
Great Lakes Impacts:
Ictiobus bubalus has a moderate environmental impact in the Great Lakes. Ictiobus bubalus is a known host for a large number of native and non-native parasites (McIntosh and Self 1955, Self and Campbell 1956, Osborn and Self 1966, Lom and Con 1996, Hersog and Barger 2019). I. bubalus significantly increases water turbidity and may impact nutrient cycling (Shormann and Cotner 1997; Goetz et al., 2014).
There is little or no evidence to support that Ictiobus bubalus has significant socio-economic impacts in the Great Lakes.
Consumption of I. bubalus has been sporadically associated with Haff disease-like illnesses involving sudden onset muscle pain and weakness due to skeletal muscle rhabdomyolysis (Deeds et al., 2022; Literman et al., 2023); however, such reports are rare.
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.
Control
Biological
There are no known methods of biological control for Ictiobus bubalus.
Physical
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
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 reference list)
Author:
Fuller, P. and K. Hopper
Contributing Agencies:
Revision Date:
1/10/2024
Peer Review Date:
9/10/2011
Citation for this information:
Fuller, P. and K. Hopper, 2024, 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: 1/10/2024, Peer Review Date: 9/10/2011, Access Date: 12/15/2024
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.