dorsal fins and the pectoral fins of Syntontis species are hardened into stiff spines. In S. petricola, the spine of the dorsal fin is long, about as long as the head, is slightly curved, is smooth on the front and with fine serrations the back, and ends with short, white filament. The remaining portion of the dorsal fin is made up of seven dark branching rays. The spine of the pectoral fin is slightly curved, roughly as long as the dorsal fin spine, with large serrations on the back side. The pectoral spine ends in short, white filament. The rest of the pectoral fins are made up of eight to nine branching rays. The adipose fin is large, does not contain any rays, and has a convex shape. The pelvic fin contains one unbranched and six branched rays. The front edge of the pelvic fin is vertically aligned midway between with the back edge of the dorsal fin and the front edge of the adipose fin. The anal fin contains three to four unbranched and seven to nine branched rays; it is vertically aligned with the center of the adipose fin. The tail, or caudal fin, is forked, with rounded lobes, and contains eight rays on the upper lobe, nine rays on the lower lobe. The mouth of the fish faces downward and has wide lips that contain papilla. All members of Syndontis have a structure called a premaxillary toothpad, which is located on the very front of the upper jaw of the mouth. This structure contains several rows of short, chisel-shaped teeth. In some species, this toothpad is made up of a large patch with several rows in a large cluster. In other species of Syndontis, this toothpad is clearly divided into two separate groups, separated by a thin band of skin that divides the toothpad. This character is used as a method of differentiating between to different but similar species of Syndontis. In S. petricola, the toothpad is interrupted, or clearly divided between the groups of teeth on the toothpad. On the lower jaw, or mandible, the teeth of Syndontis are attached to flexible, stalk-like structures and described as "s-shaped" or "hooked". The number of teeth on the mandible is used to differentiate between species; in S. petricola, there are 31 to 50 teeth on the mandible, arranged in a six short rows. Some of the species of