|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.