Olive Rockfish, Sebastes serranoides

Olive Rockfish, Sebastes serranoides, Juvenile. Fish caught from within Monterey Bay, Monterey, California, May 2022. Length: 13 cm (5.1 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.

Olive Rockfish, Sebastes serranoides. Fish caught from coastal waters off San Diego, California, December 2020. Length: 15 cm (5.9 inches). Catch, photograph and identification courtesy of Ben Cantrell, San Diego, California.

Olive Rockfish, Sebastes serranoides, Juvenile. Fish caught from coastal waters off San Diego, California, September 2017. Length: 16.5 cm (6.5 inches). Catch, photograph and identification courtesy of Ben Cantrell, San Diego, California.

Olive Rockfish, Sebastes serranoides, Juvenile. Fish caught from coastal waters off Long Beach, California, October 2015. Length: 21 cm (8.3 inches). Catch, photograph and identification courtesy of Chris Wheaton, Fullerton, California. Identification reconfirmed by Milton Love, University of California Santa Barbara, Santa Barbara, California.

Olive Rockfish, Sebastes serranoides. Fish caught from coastal waters off San Diego, California, October 2014. Length: 26 cm (10 inches).  Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.

Olive Rockfish, Sebastes serranoides. Fish caught from coastal waters off Ejido Eréndira, Baja California, February 2015. Catch, photograph and identification courtesy of Chris Wheaton, Fullerton, California.

The Olive Rockfish, Sebastes serranoides, is a member of the Rockfish and Scorpionfish or Scorpaenidae Family, and is known in Mexico as rocote falsa cabrilla. Globally, there are one hundred eight species in the genus Sebastes, of which fifty-three are found in Mexican waters, all in the Pacific Ocean.

The Olive Rockfish has a narrow elongated bodies with a depth that is 29% to 33% of standard length. They are streamlined and lack head spines. They have a dark greenish-brown or brown coloration dorsally which gradually changes to lighter greenish-brown, brown or gray ventrally. They have greenish or light colored blotches just below their dorsal fin and greenish-yellow or drab fins. Their head is mid-sized with a small terminal mouth and medium sized beady eyes. Their anal fin has 3 spines and 8 to 10 rays; their caudal fin is square to slightly indented; their dorsal fin has 12 to 14 spines and 15 to 17 rays; and, their pectoral fins have 17 to 19 rays. They have 29 to 36 gill rakers and their body is covered with scales.

The Olive Rockfish are found as solitary individuals or in small groups throughout the water column and very close to structures from shallow coastal waters to depths up to 172 m (565 feet). They are often found mixed in with schools of Blue Rockfish and in the same habitat as Black-and-Yellow Rockfish, Blue Rockfish, Copper Rockfish, Gopher Rockfish, and Kelp Rockfish. They reach a maximum length of 61 cm (2 feet 0 inches), with females being larger than males. As of January 1, 2023, the International Game Fish Association world record stood at 1.93 kg (4 lbs 4 oz) with the fish caught in coastal waters off Santa Cruz, California in July 2014. They consume juvenile Rockfish and crustaceans. They are known to migrate vertically and spend nights on the ocean bottom. Reproduction is oviparous with each female releasing between 30,000 and 490,000 pelagic eggs annually. They have a lifespan of up to 30 years. The Olive Rockfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Olive Rockfish is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found only from Guerrero Negro, Baja California, northward along the central and northwest coasts of Baja.

The Olive Rockfish is easily confused with the Yellowtail Rockfish, Sebastes flavidus (more deeply pigmented; brightly colored dark brown back with light blotches; bright yellow fins; yellow or green stripes on head; scales with orange-brown or brown flecks).

From a conservation perspective the Olive Rockfish has not been formally evaluated. They are a minor component of the West Coast commercial fishery taken predominately by gillnets and by hook and line. They are an important component of the recreational catch off the coast of Southern California, however, populations have declined by approximately 80% in the last forty years.