This is a large fish that can grow up to 25.5" in length. Relatively elongate for a sucker, the back area between the head and dorsal fin is somewhat elevated. The mouth is entirely under the snout, with thick lips, of which the upper lip has eight rows of coarse papillae, the second and third rows from the inside being significantly larger. Color is generally blackish above, with a faint pattern of blotches or spots, a narrow rosy band on the anterior part of each side, while the underside is white. The long anal fin is placed well back, the tip reaching as far back as the base of the caudal fin. The anal fin has 7 rays, while the dorsal has 13 rays.