A member of the Catostomidae family of suckers, the bigmouth buffalo is so called because of its humped back.
IdentificationThe robust and deep-bodied bigmouth buffalo has a large head with a big, distinctively oblique, and toothless mouth. This terminal, thin-lipped cavity angles downward when closed, although the edge of the upper lip is practically on a level with the eyes.
The sickle-shaped dorsal ﬁn is characterized by a taller lobe at the middle of the back that tapers off into a shorter lobe; the whole ﬁn extends to the caudal peduncle. It is the only member of the sucker family with its mouth directly in the front of the head.
The color of the bigmouth buffalo may be gray, coppery olive brown, or slate blue on the back, and the sides are yellowish olive, fading to a white belly; all the ﬁns are blackish in tint.