M. parallelus coloring juvenile and female fish have yellow to white belly, with a broad black stripe that extends through the eye and back to the caudal fin. Above this marking is a yellow to white stripe, which runs below another black stripe. On the crest of the back is another yellow to white marking. The dorsal fin is black in color, as are the anal and pelvic fins. The male has a black body with three to four blue stripes. The first of these stripes runs from the eye, back to the caudal fin. The second, third, and fourth runs, alternating with black stripes, above the first one. All the fins are black. A single male and several females make the most desirable group.