About 90 percent of the bigmouth buffalos diet consists of small crustaceans. It also feeds on algae and other plant matter, but very seldom eats insects, insect larvae, or other fish. The following are fishing methods used to catch this fish:
It is the largest member of the sucker family, growing to over 70 lb. (31 kg). In general body shape, it very much resembles the carp. The dorsal fin is similar, beginning with a tall lobe near the middle of the back and continuing to a lower portion nearly at the tail. The carp has a single serrated spine at the beginning of the dorsal fin, while the bigmouth buffalo has no spines in any of the fins. The toothless mouth is relatively large and wide, and slants downward when closed. The upper lip begins almost on the same level with the eyes. In comparison, the mouth of the smallmouth buffalo, is smaller, almost horizontal when closed, subterminal, and protracts downward in typical sucker fashion. The body of the bigmouth buffalo is coppery olive-brown to slate-blue above, becoming lighter toward the belly, which is white.