Bigmouth Buffalo
Ictiobus cyprinellus Valenciennes, 1844

member of the Sucker Family (Catostomidae)

photo by Konrad Schmidt












What's In a Name?
Bigmouth Buffalo: refers to the largemouth that is not turned down as it is in all other buffalofishes and suckers

Ictiobus (Ick-tee-o´-bus) means "bull fish" in Greek
cyprinellus (sigh-prin-ell´-us) means "small carp" in Latin


    Where Do They Live?

Bigmouth buffalo used to be much more widespread and abundant in Minnesota than they are today.  In the late 1800s and early 1900s, there were countless numbers in our southern lakes, and there were even populations in the upper Mississippi River near Brainerd and Grand Rapids.  Bigmouth buffalo are still fairly common in the lower Minnesota, Mississippi, and St. Croix River systems, but they are rare in the Red and Missouri river systems.  In the summer of 2001, for the first time in almost 100 years, a bigmouth buffalo was caught in the upper Mississippi River (just below the Blanchard Dam).

Bigmouth buffalo live in lowland lakes, sloughs, and big rivers with slow to still waters and bottoms of mud, silt, sand, and gravel.  They are especially abundant in flood plain and oxbow lakes.  Bigmouth buffalo often are found in association with northern pike, black bullhead, black buffalo, smallmouth buffalo, common carp, freshwater drum, and lake sturgeon.



How Big Do They Get?
How Long Do They Live?
The bigmouth buffalo is the largest member of the sucker family in Minnesota.  It can effortlessly reach up to the immense weight of 22.7 kg (50 lbs) and the common length s anywhere between 350-600 mm (14-24 in).  The Minnesota state's record for this fish is 18.5 kg (41lbs11oz) caught form the Mississippi River in Goodhue County.  They are also known to reach the old age of 10-15 years old.

    What Do They Eat?
This fast growing fish needs a lot of food to keep up with its growth.  The bigmouth buffalo competes with many of the fish that is shares a habitat with for the same food items, one example is the common carp.  The buffalo eats plankton, copepods, cladocerans, bottom plants, aquatic insects, mollusks, small fish and fish eggs.

What Eats Them?
Since the growth rate is so rapid, and the shape and size of the body the adult buffalo is not preyed upon very often.  The newly hatched buffalos are preyed upon by the predatory fish that share the same habitat, such as northern pike, black bullheads, walleyes, and burbot, but are affected by it very little.  With the growing popularity for the flesh of this fish, humans are becoming the only true predator on this fish.  


How Do They Reproduce?
Bigmouth buffalo spawn in April or May in Minnesota, depending on how far north the population is. Adults migrate into the shallow bays and inlets of lakes or into sloughs and flooded marshes of large rivers. Sometimes they can be seen swimming over the tops of one another as they move through small, shallow inlets into the sloughs. They spawn at all hours of the day over low, sparse vegetation, rocks, or even mud but in clear water. Spawn is done in groups of 3-5 fish, with the female in the middle. She thrashes through the water making huge ripples and smacking the surface with her tail. As she releases her eggs, the males push in all around in order to move into position to fertilize the eggs. The whole spawning process makes a great deal of noise and sends water in every direction. A single female can lay 100,000-750,000 eggs, depending on her size. The fertilized eggs become sticky and attach to the first thing they touch. They receive no care from the parents. The embryos hatch after a period of 1-2 weeks, and the larvae remain in shallows and feed.


Conservation and Management
Bigmouth buffalo are not nearly as abundant today as they were in the early 20th Century. Enormous numbers were harvested by the commercial fishing industry at that time. Declining populations and a depressed market for this species has resulted in fairly small commerical harvests over the past 40 years. Today populations are smaller, but still in good condition. This species has no special conservation status in Minnesota.





Permission is granted for the non-commercial educational or scientific use of the text and images on this Web document. Please credit the author or authors listed below.

Photographs by Konrad P. Schmidt
Text by Nicole Paulson & Jay T. Hatch in cooperation with
the Minnesota Department of Natural Resources' MinnAqua Aquatic Program

This page developed with funds from the
MinnAqua Program (Minnesota Department of Natural Resources, Division of Fisheries)
and the
Sport Fish Restoration Program (Fish and Wildlife Service, US Department of the Interior)

Maintained by Jay T. Hatch
General College and James Ford Bell Museum of Natural History
University of Minnesota, Minneapolis/St. Paul

Last updated 22 April 2003