Medialuna californiensis; from the Spanish word medialuna (halfmoon, referring to the shape of the tail) and californiensis (California, where first found).
Catalina blue perch, blue perch or blue bass.
Halfmoon are perch-shaped but heavier bodied; they’re similar in many ways to opaleye. Their coloring is normally dark blue above and light blue below. Their tail is shaped like a half-moon.
From Gulf of California, Mexico to the Klamath River.
Halfmoon are found in shallow-water, rocky areas and kelp beds. They’re often in small loose schools in the mid-water area and, at times, mixed in with schools with pileperch.
Common at southern and central California piers which are located near rocks, reefs or kelp. They’re common as far north as Cayucos but occasionally taken as far north as Santa Cruz. Best bets: Ocean Beach Pier, Hermosa Beach Pier, Redondo Harbor Sportfishing Pier, Santa Monica Pier, Gaviota Pier, the Green Pleasure Pier at Avalon and the Paradise Cove Pier.
Halfmoon will take almost any bait but they prefer fresh mussels or small crabs. When schools are present, a small strip of squid will often work, and you will lose far less bait.
A good eating, mild-flavored fish.
Halfmoons are good fighters, very similar to opaleye and the larger perch. They will eat almost anything in their environment including red, green, and brown algae, sponges, bits of seaweed, green moss, shrimp, mussels, squid, and fish. Apparently they have a hard time deciding whether to be vegans or meat eaters which may explain their scrappy and perhaps irritable nature.