Aspects of the Life History and Ecology of the Flag Rockfish, Sebastes rubrivinctus (Jordan and Gilbert, 1880)

The flag rockfish, Sebastes rubrivinctus, is a medium-sized rockfish (maximum total length = 44 cm) that lives from Stonewall Bank (44° 31′ N, 124° 26′ W), Oregon to southern Bahía de Sebastián Vizcaíno (28° 06′ N, 114° 50′ W) central Baja California, most commonly from central California to at least off Bahía San Quintin, northern Baja California, at depths of 30–431 m. We report on flag rockfish age, growth, maturity, reproduction, food habits, habitat and depth distributions, intraspecific spatial distribution, and associations with other fish species. We found this species is relatively short-lived, particularly compared to their closely related congeners, redbanded rockfish (S. babcocki) and tiger rockfish (S. nigrocinctus). This is in keeping with relatively warm-water and more southerly species having shorter life spans than those closely related species typical of colder and more northerly waters. It is likely that flag rockfish are feeding generalists. Along the northeastern Pacific, the vast majority of rockfish species release larvae during winter and spring; thus, this species' spring–fall parturition is relatively unusual. We suggest that this unusual parturition season is linked to the early life history of this species, which may be linked to pelagic juveniles associating with drifting material, such as kelp mats, material that are generally more prevalent during fall and winter. Our study reinforces the results of several other studies that this is a relatively solitary, mid-continental shelf species found primarily in rocky habitats. It is a member of the “sheltering” guild, as both older juveniles and adults tend to inhabit boulder fields and other rocky areas that contain caves and crevices. Younger flag rockfish recruit to depths slightly shallower than those occupied by adults. However, by about 20 cm (about 5 years old), when many of these fish were either preadults or just mature, this ontogenetic movement seems to have decreased or ceased.