Plectorhinchus lineatus (Oblique-banded Sweetlips)

From Fishes of Australia: A pale grey sweetlips fading to white below, with yellowish lips, diagonal black stripes on the upper sides (sometimes broken up into spots), yellow dorsal, anal and caudal fins with black spots, and yellow pectoral and pelvic fins with a red anterior blotch.
Juveniles and subadult fish have black horizontal stripes along the body that become increasingly diagonal with growth.