The quillback rockfish is a component of central and northern California=s nearshore benthic assemblage. Quillback rockfish are relatively small, and are of Astout@ morphology; a characteristic common among nearshore Sebastes found in close association with the bottom. They are usually orange-brown to black in color with a yellow or orange pale area between the eye and pectoral fin.

Distribution, Stock Structure and Migration.

Quillback rockfish are known from the Gulf of Alaska to San Miguel Island in southern California. They are considered common between southeast Alaska and northern California. They are considered a shallow to moderate depth species although they rarely occur to depths of 900 ft.

No stock structure has been determined for quillback in California.

Like other Sebastes of shallow, benthic habitat, individual quillback rockfish are not known to range far. Tagging studies in central California and Washington have shown quillback to be residential (no movement other than diurnal) or to show movement of less than 6 miles. They have also demonstrated homing ability and specific diurnal movement patterns.

Age and Growth

In California, quillback rockfish have been aged to 15 yr, but are known to live longer: They have been aged to 76 yr in Canada. Quillback can grow to 24 inches.

Reproduction, Fecundity and Seasonality

In California, size at first maturity as well as 50% maturity for males is 8.7 in. TL (4 yr.), and for females is 10.2 in. TL (6 yr.) As with all Sebastes, quillback have internal fertilization and are viviparous. In California, mating takes place in the late winter/early spring, and parturition April through July; with a peak in May and June. After roughly one or two months in the plankton, they begin to settle near shore.

Natural Mortality

Natural mortality (M) values have been calculated for quillback rockfish stocks in Washington. It has been calculated to be 0.1253 via tag and recapture methods, and 0.115 via Hencke survivorship/age frequency curve.

Diseases

No information on disease in quillback rockfish was found.

Predator/Prey Relationships

As planktonic larvae, quillback rockfish are known to consume nauplii invertebrate eggs and copepods. After they settle in the shallow, nearshore areas they remain zooplanktivorous and feed on crustaceans. As adults their habit is more benthic, and they are known to feed on a variety of prey such as crustaceans; small fish, including rockfishes and flatfishes; bivalves and fish eggs.

As juveniles, they are preyed upon by fishes, including larger rockfishes (such as yelloweye), lingcod, cabezon and salmon. Various marine birds and pinnipeds take juvenile quillback as well. Adults are also subject to predation by larger piscivorous fishes including some sharks, as well as pinnipeds, and possibly, river otters.

Competition

Though quillback rockfish occur with a host of other nearshore benthic species, no information on competition was found.

Critical Habitat

The larvae of quillback rockfish are planktonic. After about one to two months in the plankton, they begin to settle near shore. Young-of-the-year quillbacks are found among relatively shallow, low-relief rocky substrate and shallow, vegetated habitats such as kelp and eelgrass beds. Juveniles tend to inhabit the very nearshore benthos as well, and are found over both low and high rocky substrate. Adults are most often found in deeper water and are solitary reef-dwellers living in close association with the bottom. They are often seen perched on rocks or taking shelter in crevices and holes. Adults have also been noted to retreat to eelgrass beds at night. Quillback are also associated with the rock-sand interface, but are rarely seen in the open away from suitable cover.

Status of Stocks

No stock assessment has been done for this species. Quillback rockfish are a minor component of the nearshore recreational fishery with decreasing occurrence south of northern California. They are also a component of the nearshore commercial fishery.