Variable. Generally dark brown to black above with diffuse dark marbling and mottling on a lighter brown background. Areas of densely congregated iridophores form white, cream, or golden flecks or stripes, particularly at the body flanks, along the edge of the anterior upper tail fin, and at the lower part of the tail base. Between these areas, longitudinal concentrations of melanocytes are present, especially at the flank and/or base of the tail. These light and dark elements give many specimens a longitudinally striped appearance. The fins are also mottled and appear overall dark. Specimens become more heavily pigmented with growth and development. The ventral side is well pigmented and mostly opaque (semitransparent in early stages), sometimes with white or cream spots and stippling in the abdominal region. The gut coil is faintly visible or invisible; heart and gills are indistinct (more distinct in early stages). The oral disc is well pigmented and ventrally without conspicuous black spots. Some individuals have an orange tinge to the oral disc. Myosepta and the lateral tail vein are invisible.