This species is distinguished by the following characters: second dorsal-fin rays I, 9-10; anal-fin rays I, 9; vertebrae 10+17-18= 27-28, usually 10+18=28); first spine of first dorsal-fin greatly elongated or filamentous in males; second dorsal fin usually reaching to, or beyond, caudal-fin base when adpressed in adult, length of longest ray 17.5-21.8% of SL; length of longest ray of anal fin 12.6-18.1% of SL); scales on body restricted on posterior half of body, except for isolated patch of scales just behind pectoral-fin base; no pelvic frenum; length of pectoral fin 23.2-30.6% of SL); caudal-peduncle length 20.3-23.6% of SL; cephalic sensory canals and associated pores absent; an orange line present at the middle of dorsal fin in life (Ref. 75132).