This species is distinguished by the following characters: with a single (or multiple in juveniles) row of enlarged, conical and morphologically distinct dermal denticles over dorsal longitudinal midline, from midlength of the pectoral fin base to origin of first dorsal fin (in some specimens, to origin of caudal fin); dorsal midline denticles are with enlarged and rounded basal plate, 3-4 times diameter of other dorsal denticles, crown with several median ridges (10-12), and crown apex acute and smooth, without ridges (vs. dorsal midline denticles on trunk morphologically similar to other trunk denticles and barely organized in a row in S. occulta and S. argentina); differs from S. occulta by having larger and fewer white blotches on dorsal surface, without surrounding blackish rings (i.e. absence of ocelli-like markings) and smaller in size at maturity, from 73.0-80.0 cm TL (vs. greater than 100.0 cm TL in S. occulta);

differs from S. argentina by its ligther background colour, light to dark brown (vs. dark brown to reddish brown), with larger and fewer white blotches over dorsal surface, with a pair of enlarged, conical and morphologically distinct dermal denticles between spiracles (vs. interspiracular surface covered by smaller dorsal denticles, no enlarged denticles), the lower number of tooth rows with 18-22 vertical rows in both upper and lower jaws, tooth formula 9-9 to 11-11/9-9 to 11-11 (vs. 12-12/12-12 in i>S. argentina), and with a straight external pectoral fin margin (vs. with convex anterior half of external margin). Colouration: dorsal color pattern of light to dark brown background, with several white, creamy-white or yellowish large and rounded blotches variable in size (between one-half to 1.5 times eye-length) on entire dorsal surface (Ref. 95520).