Girella nigricans, commonly known as the opaleye or rudderfish, is a species of sea chub found in the Eastern Pacific, from California to southern Baja California. A rarely documented isolated population also exists in the Gulf of California, which might be genetically different from the rest of the species. They are commonly found in shallow waters and intertidal zones, usually over rocks and kelp beds, at depths of 1 to 32 m (3.3 to 105.0 ft). They feed primarily on algae, but will occasionally consume sessile invertebrates (including crustaceans, worms, and molluscs). They are considered commercially important game fish.