This species is distinguished by the following set characters: anterior nostril is a short tube with simple cirrus on posterior rim; maxilla rigid, not produced as a thin flexible lamina posteriorly; no supramaxilla; subopercle with a broad, fan-like flap; vomer with one tooth; pale buccal area surrounding esophageal opening; body with 45-52 oblique body scale rows in longitudinal series; vertebrae 10 + 18; spinous dorsal fin with black blotch, when present, between spines 2-5. Colouration: body with five poorly defined irregular bands and sides sometimes with diagonal rows of pale spots smaller than eye diameter; when present, a black blotch in spinous dorsal fin between spines 2-5; buccal area surrounding esophageal opening pale. Also easily distinguished from its congeners by the divergence in the mitochondrial gene COI, as specimens form a monophyletic group that differs from its closest relative (O. maxillosus) by an average of 9% (654 bp analyzed) (Ref. 129348).