Mouth and snout: Slightly subterminal or terminal, patches of numerous fine teeth on jaws. 8 obvious barbels (4 pairs; 2 pair on chin, 1 pair on side of upper jaw (near corner of mouth), 1 pair on top of snout). Body patterning, color, and scales: Solid color predominates, but may be somewhat mottled on lower flanks. Body usually black to yellowish brown, with a white or yellow belly. Fins darkly pigmented. No scales. Body shape and size: Body dorsal-ventrally flattened with a rounded head; in cross section approximately oval (with a long horizontal axis) to round with a flattened ventral surface.