Catalina Blue Perch – Medialuna californiensis.  Common names: Catalina blue perch, half moon perch (due to the tail fin shape resembling a crescent moon), blue bass, black perch, blue perch, blue wizard.

Identifying Characteristics and Biology

  • The name ‘half moon’ or ‘halfmoon’ comes from its unique tail fin shape resembling a crescent shaped moon.
  • Catalina blue perch color is steel- or slate-blue to blue backs, and silver and gray bellies.
  • Adult fish can reach to almost 20 inches, although they mature at around 7 inches.
  • Catalina blue perch feed on seaweed and small invertebrates.

Range and Habitat

  • Typical range: from Vancouver Island to the Gulf of California, from the surface to about 130 feet deep.
  • Catalina blue perch like shallow rocky areas, and are fond of kelp beds, and anywhere there is seaweed growing.
  • This fish can be found under kelp patties many miles offshore

Market Forms

  • Catalina blue perch are great eating fish.



Love, Milton. Probably More Than You Want to Know About the Fishes of the Pacific Coast. Santa Barbara: Really Big Press, 1996. Print.

“Marine Sportfish Identification: Other Fishes.” Marine Sportfish Identification: Other Fishes. CA Department Fish and Wildlife, 17 Oct. 2013. Web. 20 Feb. 2014.


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