Smallmouth Buffalo

Smallmouth Buffalo, Ictiobus bubalus

The Smallmouth Buffalo, Ictiobus bubalus, whose common Spanish name is matalote boquín, is a member of the Sucker or Catostomidae Family, known collectively as matalotes in Mexico. Globally, there are 78 species in the Catostomidae Family and five species in the genus Ictiobus, of which four are found in the freshwater systems of mainland Mexico.

The Smallmouth Buffalos have stocky and laterally compressed bodies with a depth that is 36% to 42% of standard length. They have a characteristic hump over their gill covers and a deep caudal peduncle. They are uniformly gray to copper-greenish-brown dorsally and transition to pale yellow or white ventrally. Their fins are heavily pigmented and darker toward the tips. Their head has a steep profile with large black eyes, a small distinctive sucker-type mouth, and an inferior snout. Their anal fin has 8 to 10 rays. Their caudal fin is forked and symmetrical. Their dorsal fin has 26 to 31 rays and is continuous with a long base; it is long at the front with a blunt point then tapers toward the caudal peduncle. Their pelvic fins are low on the body and protrude ventrally. They have a prominent lateral line and are covered with large smooth scales.

The Smallmouth Buffalos are found in clean and moderate to fast moving streams and in lakes and ponds with dense aquatic vegetation over silty bottoms. They reach a maximum length of 1.12 meters (3 feet 8 inches) and weight of 37.3 kg (82 pounds). They are generally non-migratory but are temperature-sensitive, thus will move to temperature environments that vary by a few degrees year-round. They are detritivores and consume vegetation and other organic material off the bottom. They also consume algae, zooplankton, insect larvae, mollusk larvae, and small crustaceans. Reproduction occurs in shallow waters with each female broadcasting tens of thousands to hundreds of thousands eggs that sink, adhere to vegetation, and hatch in approximately 10 days. They have a lifespan of up to 18 years.

The Smallmouth Buffalos have a limited range in Mexican waters being found in the freshwater systems in the extreme northeast corner of the mainland.

The Smallmouth Buffalo can be confused with the Bigmouth Buffalo, Ictiobus cyprinellus (not found in Mexican waters; large terminal mouth), the Black Buffalo, Ictiobus niger (deeper body; significantly smaller eyes), and the Common Carp, Cyprinus carpio (has barbels).

The Smallmouth Buffalos are the most common commercial freshwater fish in North America. They are a quality food fish and are also processed into fish meal and used as animal feed. They are pursued at high levels by recreational anglers with both spinning and fly tackle. They are also raised in commercial farm ponds and have been stocked. They have been accidentally introduced in numerous locations in the south and southwest United States. From a conservation perspective, they are currently considered of Least Concern, due to their wide distribution range and large population size.

Smallmouth Buffalo, Ictiobus bubalus. Fish caught in the Chippewa River, Wisconsin, March 2009. Length: 46 cm (18 inches). Catch, photo, and identification courtesy of Josh Leisen (, Gaylord, MI.