A rarely documented isolated population also exists in the Gulf of California, which might be genetically different from the rest of the species.

[1] 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).

This is important for the health of the kelp forest community as it allows other species of algae and sessile invertebrates to compete for space.

[8] Opaleye are pelagic spawners,[4] where the eggs and larvae are released into open water and are free floating.

Living in tidepools allows the juveniles to grow and develop without the presence of large predators that do not inhabit this area.

[9][6] After living in the intertidal zone for a short time, the young opaleye undergo both morphological and behavioral changes, usually within a week.

Additionally, they stop schooling and begin to spend time in areas where they can quickly hide under rocks in order to protect themselves from predators.

Their feeding habits depend on factors such as habitat, water temperature, and digestive system morphology.

[10] Predators of opaleye include seabirds such as cormorants, terns, and bald eagles, as well as larger fish species, seals, and sea lions.

The jaws and teeth of opaleye have become adapted to their feeding habits, allowing them to efficiently graze on algae.

[9] Opaleye exhibit homing behavior, meaning that they continuously return to a specific tidepool or area.

This behavior decreases as the fish grow older, because they eventually leave the intertidal area for the subtidal zone.

[13] Some juvenile opaleye individuals have shown cleaning behavior, where they remove scales or ectoparasites from other fish species.

[14] Pre-juvenile opaleye have been known to sometimes aggregate under floating objects like masses of kelp and jellyfish, both offshore (before reaching the intertidal zone) and in tidepools.

The geographic range of opaleye does include multiple Marine Protected Areas, although the species itself does not have any conservation measures.