Kelp Rockfish

Kelp Rockfish, Sebastes atrovirens

The Kelp Rockfish, Sebastes atrovirens, whose common Spanish name is rocote sargacero, is a species in the Rockfish and Scorpionfish or Scorpaenidae Family, known collectively as escorpiones, lapons or rocotes in Mexico. Globally, there are 124 species in the genus Sebastes, of which 49 are found in Mexican waters, all in the Pacific.

The Kelp Rockfish have thin oval bodies with a depth that is 39% to 43% of standard length. Adults vary in color from white to various shades of brown, yellow, and red. Their gill covers are dark and their body is covered with darker flecks. Juveniles have five brown vertical bars over a clear, white or light brown background. As fish mature, they lose their vertical bars and display specks in faint vertical columns. Their head has a sharp snout, large eyes, multiple large spines, and a mid-sized terminal mouth. Their anal fin has three spines and six to eight rays; their caudal fin is square; the dorsal fin has 13 spines and 12 to 15 rays; and their very large pectoral fins have 16 to 18 rays. They have 28 to 36 gill rakers.

The Kelp Rockfish are found both demersal and mid-water in complex habitats including kelp forests and rock structures at depths up to 270 feet. They reach a maximum length of 43 cm (17 inches). They are normally found as solitary individuals or in small aggregations. They are generally non-migratory with small home ranges. They feed on zooplankton, small fish, crabs, shrimp, and snails. Juveniles are a favorite prey of Bocaccios. Reproduction is oviparous with each female releasing between 10,000 and 340,000 pelagic eggs annually. They have a lifespan of up to 25 years, however, very little is known about their behavioral patterns.

In Mexican waters the Kelp Rockfish have a limited distribution and are found from Guerrero Negro northward along the central and northwest coasts of Baja.

The Kelp Rockfish is most likely confused with the Brown Rockfish, Sebastes auriculatus (thicker and deeper body; brown to red-brown coloration; orange lines radiating backwards from eyes) and the Grass Rockfish, Sebastes rastrelliger (heavier body; green coloration; small black spots on body; short stubby gill rakers). Juveniles are very difficult to distinguish from juvenile Black-and-yellow, Copper, and Gopher Rockfish.

The Kelp Rockfish are not considered an important food fish. They are sold as a live fishery component and can be found in ethnic fish markets of Northern Baja. They are caught with good frequency by recreational anglers from boats, piers, and jetties and by sports divers. A significant decline in their population levels has been documented over the last 30 years.

Kelp Rockfish, Sebastes atrovirens. Fish caught from shore in San Francisco, California, February 2014. Length: 23.0 cm (9.1 inches). Catch, photo, and identification courtesy of Eli (obsessiveangling.wordpress.com). Identification reconfirmed by Milton Love, University of California, Santa Barbara, Santa Barbara, CA.