The spinner is a seldom recognized shark, and it is frequently confused with the blacktip. Some fishermen know it by its slender shape, long pointed snout and small eyes. To the trained observer, the two species may be separated by the position of the first dorsal fin and by the shape of the lower jaw. The dorsal fin of the spinner originates above and behind the pectoral fin, whereas that of the blacktip is positioned in front of it. The trailing edge of the mandible of the spinner is straight, but it is distinctively notched in the blacktip.