Has the deepest body of any species of Coius, 2.1-2.4 times in SL. Specimens from mainland Southeast Asia invariably with five full bars, specimens from Borneo with 6-7 bars, all usually continued across ventral surface of body. First bar extending uninterrupted and undiminished across opercle and onto thoracic region, and continued across ventral surface of body; a well defined black mark on ventral surface of body immediately anterior to base of pelvic fins (not present in other Coius). Partial bars almost invariably absent. Branched dorsal rays 14-18; branched anal rays 9-11, usually 10 (Ref. 10425).