Fish Bulletin 126. Life History Studies on Ten Species of Rockfish (Genus Sebastodes)

Author(s): Phillips, Julius B | Abstract: Life-history information is extremely important in fisheries management, especially details regarding age, fecundity, growth, food habits, and so on. Such knowledge has been lacking for the principal species comprising commercial rockfish catches from California waters. Recent studies have furnished details on annual growth, size and age at maturity, weight-length relationship, season of spawning, fecundity, and feeding habits for 10 species of rockfish (genus Sebastodes) that are commonly taken off California. These are bocaccio, S. paucispinis, chilipepper, S. goodei, yellowtail rockfish, S. flavidus, canary rockfish, S. pinniger, vermilion rockfish, S. miniatus, widow rockfish, S. entomelas, dark-blotched rockfish, S. crameri, splitnose rockfish (rosefish), S. diploproa, stripetail rockfish, S. saxicola, and shortbelly rockfish, S. jordani. Although 57 varieties of scorpaenids (family Scorpaenidae) exist off the coast of western North America, only two had been studied in any detail prior to this time. Wales (1952) published a partial life history of the blue rockfish, Sebastodes mystinus, and Westrheim (1958), and Alverson and Westrheim (1961) published data on the biology of the Pacific ocean perch, S. alutus. The blue rockfish is a shallow water form, caught mainly by sportfishermen in California. Although poorly represented off California, Pacific ocean perch are abundant in offshore waters of the Pacific Northwest, where they are the primary rockfish sought by otter trawl fishermen. In California waters, the rockfish family is now represented by 50 species of Sebastodes (rockfish or "rock cod"), 2 species of Sebastolobus (channel rockfish), and 1 of Scorpaena (sculpin). This fish family is one of the most important and colorful in our waters. Most of the species are highly desirable for food and are subjected to both commercial and sportfishing pressure. Only a few are too small to be of direct value for human consumption. Even these are utilized as food by other fishes, often by larger forms of rockfish. Nine of the species in the present study are of considerable commercial value; the tenth, the shortbelly rockfish, is a small form whose greatest value probably is as food for salmon (Merkel, 1957) and similar predators. As time permits and based upon future catch composition evaluations, other prominent species will be studied in similar detail. The most important of these at present seem to be the shortspine channel rockfish, Sebastolobus alascanus, and flag rockfish, Sebastodes rubrivinctus, in northern California; the speckled rockfish, S. ovalis, in central California; and the bronzespotted rockfish, S. gilli and cow rockfish, S. levis, in southern California.