The bigmouth buffalo is a dark-colored sucker with a deep, rather thick body and a long, sickle-shaped dorsal fin. The eyes are small and closer to the tip of the snout than to the rear margin of the gill cover. The mouth is oblique. The lower fins have much dusky pigment.
The back and sides are brownish or blackish with coppery and greenish reflections. The scales are large and not prominently dark-edged. The belly is whitish or pale yellow. All fins are blackish, the lower fins often whitish along free margins. Breeding males are slightly darker and have small tubercles distributed over the head, body, and fins.
Similar species: The bigmouth buffalo is similar to the smallmouth buffalo and black buffalo, but it has a large, oblique mouth and has thinner, less strongly grooved lips. The front of the upper lip is about level with the lower margin of the eye. The length of the upper jaw is much greater than the diameter of the eye. The bigmouth is more slender than the smallmouth buffalo, the body depth going about 2.5 to 3.3 times into the standard length. The forward part of the back is rounded or only weakly keeled.
Total length: 15–27 inches (maximum 48 inches). Weight: 2–14, sometimes up to 30 pounds (maximum 80 pounds).
Occurs over much of the state. Most abundant in the Missouri River and its larger, prairie-stream tributaries of the northern half of Missouri. It is also abundant along the Mississippi River and in the Lowland ditches and streams of the southeast (Bootheel), but in these areas it is usually outnumbered by one of the other buffalo species. Apparently mostly absent from the extreme southwest and south-central regions.
Habitat and Conservation
Mainly inhabits deeper pools of large streams, natural lowland lakes, and artificial impoundments. Sometimes enters rather small creeks to spawn, and the young remain in the smaller streams during their first summer of life. The bigmouth buffalo is generally more tolerant of high turbidity and is more commonly found in standing-water habitats than other buffalo species.
Commonly occurs in schools in midwater or near the bottom.
Omnivorous, feeding on invertebrates and detritus from the bottom. Young feed principally on midges and other bottom-dwelling invertebrates, while older individuals mainly eat small crustaceans. The large, terminal mouth and numerous slender gill rakers are efficient devices for straining small crustaceans from the water.
The bigmouth buffalo apparently specializes in feeding near the mud-water interface, ingesting plants and animals that hover near the bottom or rest lightly upon it. The swirling action created by a school of buffaloes as they move across the bottom with short up-and-down movements brings bottom-dwelling food items into suspension for capture.
Spawns from about late April into early May in shallow water, where the adhesive eggs are deposited over decomposing vegetation and other submerged objects. During spawning, a female is usually accompanied by two smaller males in a spawning rush across the spawning site, the males aligned beside the female in typical sucker fashion. The eggs hatch in 9 or 10 days. Bigmouth buffalo grow steadily over their first 8 years of life, and they may live up to 10 years.
Many people enjoy bigmouth buffalo meat smoked or deep fried.
Seldom taken on a hook and line; most are caught with trammel nets and other commercial fishing gear.
As a group, the buffalofishes rank second in importance to carp in the commercial fishery of the Mississippi and Missouri rivers.
Bigmouth buffalo are well-suited for artificial propagation, and in some southern states they have been raised in rotation with rice. Pond propagation is another alternative.
Suckers are one of the dominant groups of large fishes in Missouri waters. In many streams, their total poundage may exceed that of all other fishes combined. Each kind of sucker has its own particular habitat preference.
The fleshy, protrusile lips of suckers make them perfectly equipped for sucking up aquatic invertebrates from the bottom.
Small suckers, including the eggs and young of the bigmouth buffalo, are an important food source for other animals, including game fishes.