Distinguished from its congeners in possessing the following unique combination of characters: angular gill slit; subopercular groove present and continuous to pectoral fin origin; body, including dorsum, brown; head dorsum with very fine cream reticulate pattern (similar to a cream head with brown spots and blotches); dorsal, caudal and anal fins blue in life; presence of sublacrymal groove; snout rounded when viewed dorsally; absence of secondary rostrum; absence of postoral pouch; scales absent on belly; 47-65 scales in lateral line (Sabah population: 56-65, Brunei population: 47-49); pelvic fin not overlapping level of anal fin origin, adpressed dorsal fin falling short of level of anal fin origin (Ref. 56228).