 There are 19–24 tooth rows in the upper jaw, each with a narrow central cusp flanked by 2–4 pairs of smaller cusplets, increasing in number with age in males over long.There are 25–39 tooth rows in the lower jaw, each tooth with a smooth-edged, knife-like cusp and their bases interlocked to form a single cutting surface; the teeth of males over long and females over long become more erect with age.The first dorsal fin is close to the pectoral than the pelvic fins, and bear a straight, grooved spine in front.