Oval shaped, olive to gray green, usually with two pale spots below dorsal fin. Often a white bar across snout. Caudal fin square cut. They eat mostly algae and invertebrates such as shrimp, amphipods and jellies.
Females are oviparous following internal fertilization.
Spawning occurs from April-June, shedding eggs into the water column. Young appear in tidepools from July to early winter. The Opaleye is a solitary fish which sometimes gathers in small groups but not large schools. It is not clear if Opaleyes digest the algae they eat or if they only eat it to get at the invertebrates within. Larger specimens tend to lose light spots under dorsal fin.