 The mouth lacks conspicuous furrows at the corners and usually bears 15 tooth rows on either side of both jaws, plusone to two upper and one lower symphysial (jaw midline) tooth rows.Each upper tooth has a smooth to serrated edge, a narrow cusp becoming more oblique towards the corner of the mouth, and two to five coarse serrations at the base of the trailing margin.The number and size of serrations on the leading margin of the tooth cusp increase relative to those on the trailing margin as the animal grows older.