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Bigmouth Buffalo

Bigmouth buffalo, photo courtesy of Konrad P. Schmidt, copyright Konrad P. Schmidt


Bluish-green back shading to coppery-blue sides and light bluish-grey belly; deeply rounded body with a large head and mouth; dorsal fin sickle-shaped; individuals over 40 pounds not uncommon in commercial catches; form schools.


Bigmouth buffalo Distribution

The bigmouth buffalo is found throughout most of Iowa, except for the Nodaway River drainages. It is most abundant in the Mississippi and Missouri Rivers and their larger tributaries, in the river impoundments and in some natural lakes. The bigmouth buffalo is less common in the smaller tributaries of the Missouri River in the southwest part of the state.


Plankton, copepods and cladocerans.

State Record

64 lbs 6 oz.; 41.5 in. - Lake Manawa, Pottawattamie County, April 2007 - Ronald Anderson, Omaha, NE

Expert Tip

Bigmouth Buffalo are rarely caught on hook and line - if you do, hold on because these fish are strong!


The bigmouth buffalo is found throughout most of Iowa, except for the Nodaway River drainages. It is most abundant in the Mississippi and Missouri Rivers and their larger tributaries, in the river impoundments and in some natural lakes. The bigmouth buffalo is less common in small tributary streams, especially the smaller tributaries of the Missouri River in the southwest part of the state.

Body color of this fish varies from bluish-green dorsally, shading to coppery-blue on the sides, then fading to a light bluish-gray belly.  It has a deeply rounded bodywith small eyes set close to the snout.  The head is large, round, with thin lips surrounding a large, oblique mouth.  The lateral line is complete with 32 to 40 large cycloid scales.  The dorsal fin is sickle-shapedwith 23 to 32 rays. Pharyngeal teeth are short and fragile with about 165 per arch.  Adults commonly reach 15 to 27 inches in length and weigh 2 to 14 pounds.  Individuals over 40 pounds are not uncommon in commercial landing.

Bigmouth buffalo are well-adapted for life in shallow, standing water that is characteristic of lakes, impoundments, marshes and backwaters of large rivers. While it is commonly encountered in deep pool regions, the species can also be found in quiet shallow waters and tolerates high water temperatures. They prefer very shallow and slow-flowing water habitats over bottoms rich with detritus in mud and silt. It is more tolerant of high turbidity and standing water than other species. This species tolerates very turbid waters but prefers clear, organically-enriched water with heavy algae and zooplankton blooms.

Spawning commences in April when the water temperature reaches 60 degrees F. The adult fish enter flooded marshes along river bottoms enticed by a sudden rise in water temperature or by an increasing water stage from runoff. They congregate in large schools to spawn over sedges and grasses in shallows about 2 to 3 feet deep. A single gravid female sinks to near the bottom and is surrounded by several males. Together they engage in a series of rushes that pushes the female to the surface while the adhesive eggs are broadcast and fertilized at random. The eggs are unattended until they hatch after incubating 8 to 14 days. Maturity varies, but most fish are sexually mature and spawn at age 3. Fecundity of a 10-pound buffalo is around 400,000 eggs.

Growth rate of bigmouth buffalo is rapid. Specimens from the Wisconsin River had calculated body lengths of 5.2 inches at age 1 to 33.3 inches at age 12. Growth varies considerably with location. It is often found in populations with huge standing stocks, particularly in lakes and impoundments. Populations densities of up to 1,200 pounds per acre have been reported in Iowa.

The food chain of the bigmouth buffalo is quite short, utilizing mostly plankton and benthic fauna, particularly copepods and cladocerans. They comete directly with many other fish speciesat different stages of development. Bigmouth buffalo exhibit a definite behavior pattern to form schools. They are a hardy fish species that can endure oxygen concentrations less than 1 ppm and equally able to withstand warm water temperatures in excess of 90 degrees F.

Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.


Harlan, J.R., E.B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323pp.

Loan-Wilsey, A. K., C. L. Pierce, K. L. Kane, P. D. Brown and R. L. McNeely. 2005. The Iowa Aquatic Gap Analysis Project Final Report. Iowa Cooperative Fish and Wildlife Research Unit, Iowa State University, Ames.

Photo credit: Photo courtesy of Konrad P. Schmidt, copyright Konrad P. Schmidt.


Present in these Iowa water bodies:

Lake/Stream County Location Acres/Length
Red Rock Reservoir Marion 4 miles north of Knoxville 15250.00
Pool 16, Mississippi River Muscatine The amenities list are for Buffalo Shores campground in Buffalo Iowa. Amenities at other locations in Pool 16 vary by location 13000.00
Coralville Reservoir Johnson 4 miles north of Iowa City 5280.00
Saylorville Reservoir Polk North edge of Des Moines 4970.00
Storm Lake (incl Little Storm Lake) Buena Vista south edge of Storm Lake 3097.00
Trumbull Lake Clay 4 miles west, 5 miles north of Ruthven 1183.00
Lost Island Lake Palo Alto 3 miles north of Ruthven 1162.00
Silver Lake (Dickinson) Dickinson west edge of Lake Park 1041.00
Five Island Lake Palo Alto north edge of Emmetsburg 973.00
Lake Macbride Johnson 4 miles West of Solon 940.00
Lake Manawa Pottawattamie Southwest edge of Council Bluffs 747.00
High Lake Emmet 6 miles east of Wallingford 467.00
North Twin Lake Calhoun 4 miles north of Rockwell City 453.00
West Swan Lake S.W.M.A. Emmet 3m SE Gruver 379.00
Swan Lake Dickinson 2m N Superior 371.00
Ingham Lake Emmet 6 miles east of Wallingford 357.00
Elk Lake Clay 1 mile west, 3 miles south of Ruthven 261.00
Center Lake Dickinson 2 miles west, 1/2 miles south of Spirit Lake 220.00
Iowa River (Marshalltown to Coralville Lake) Iowa 104.00
Sand Lake Marshall On the Northeast edge of Marshalltown 95.00
Terry Trueblood Lake Johnson 1.5 miles south of Hwy 6 on Gilbert Street in Iowa City. 90.00
Atlantic Quarry Pond 3 Cass 60.90
Des Moines River (Stratford to Saylorville Lake) Polk 57.00
Des Moines River (Saylorville to Red Rock) Marion 50.00
Folsom Lake Mills 2 miles west of Glenwood 45.00
Prairie Park Fishery Linn 1.5 miles SSE of Cargill on Otis Road, along the Cedar River in Cedar Rapids 42.00
Iowa River (Coralville Lake to River Junction) Johnson 29.00
Mohawk Park Lake Linn East side of the Cedar River off J Ave. 26.00
Bartlett Lake Fremont ½ mile west of Bartlett 22.00
Big Lake (Including Gilbert's Pond) Pottawattamie North 25th street exit off interstate 29. Nash Blvd to Big Lake Road. Northeast Council Bluffs. 5.00
Ambroson Pit (north) Winnebago 3 1/2 miles north of Forest City 4.28
Iowa River Landing Pond Johnson Just south of I-80 at Iowa River Landing 1.90