Gill-spots mainly feed on the algal membranes of seaweeds growing on rocks, and the longest body length is 50cm. Inhabits waters between 6 and 50 meters deep on the slopes of clear reef-facing reef areas. Gills are tropical fish. Between 30 degrees north latitude and 24 degrees south latitude, adult gills live in areas below 30 meters, and juveniles live in water depths of 3 meters. The body color of the sub-adult gills is army green.

Gills The scabbard is brown overall. Small irregular grey-blue lines on the sides, a small black spot behind the eyes, thicker stripes of yellow-orange from the back to below the pectoral fins, yellow dorsal fins, dorsal and anal fins with blue edges and narrow blue lines along the base, There is a white band at the base of the caudal fin. Mouth is white. Large males develop a highly protruding forehead that extends beyond the mouth. Young gills have almost no pattern on the whole and are gray-brown. Nature is milder.