Blue Rockfish

Blue Rockfish, Sebastes mystinus

The Blue Rockfish, Sebastes mystinus, whose common Spanish name is rocote azul, is a species in the family Scorpaenidae, the Rockfishes and Scorpionfishes, known as escorpiónes or lapóns in Mexico. There are two genetic morphologies of this species: “Blue-Blotched” and “Blue-Sided”. Globally, there are one hundred twenty four species in the genus Sebastes, of which forty nine are found in Mexican waters, all in the Pacific.

The Blue Rockfish have elongated oval bodies with a depth that is 32 – 36% of standard length. The Blue-Blotched Rockfish have a blue coloration with light gray or white blotches. They have two colored cheek bars and bluish stripes across their heads. The Blue-Sided Rockfish have an olive brown coloration with more uniform blotching. Their head is mid-sized with a mid-length snout, mid-sized eyes, a relatively small terminal mouth, and a limited number of spines. The Blue-Sided Rockfish has a more pointed snout, a more prominent lateral line, and is more elongated that the Blue-Blotched Rockfish. Their anal fin has three spines and eight to ten rays; their caudal fin is rounded; their dorsal fin has 13 spines and 15 to 17 rays; their pectoral fins have 16 to 18 rays; and they have 32 to 39 gill rakers. Their body is covered with scales.

The Blue Rockfish are non-migratory schooling reef fish that are found in all parts of the water column at depths up to 1,800 feet. They reach a maximum length of 53 cm (21 inches), with females being larger than males. They are mixed in with Blacksmiths and Olive Rockfish. They feed primarily on planktonic organisms. They are found from Puerto Santo Tomas north along the west coast of Baja. Reproduction is oviparous with each female releasing up to 525,000 pelagic eggs. They have a lifespan of up to 44 years. Very little is known about their behavioral patterns and the differences in lifestyles between the two morphologies of this species.

The Blue Rockfish is most likely confused with the Black Rockfish, Sebastes melanops (strong mottled pattern; large mouth).

The Blue Rockfish are an important commercial catch in California waters. They are primarily sold live, however, they do not command high prices due to their drab coloration. They are also a major focus of recreational anglers being the most abundant catch of party boat anglers in Central California. They are also taken by spearfishermen is substantial quantity. Due to these pressures the abundance of the Blue Rockfish has significantly diminished in recent years.

Blue Rockfish, Blue Blotched Morphology, Sebastes mystinus: Pictured fish current living resident of the Birch Aquarium, La Jolla, CA, January 2008. Length: 51 cm (20 inches).
Blue Rockfish, Blue Blotched Morphology, Sebastes mystinus: Currently living resident of the Birch Aquarium, La Jolla, CA, January 2008. Length: 51 cm (20 inches).