LIFE HISTORY AND FISHERY OF THE CALIFORNIA SCORPIONFISH, 



SCORPAENA GUTTATA, 

 WITHIN THE SOUTHERN CALIFORNIA BIGHT 



Milton S. Love,i Brita Axell,i Pamela Morris, ^ Robson Collins,^ 



AND Andrew Brooks' 



ABSTRACT 



We examined the life history of the California scorpionfish in the Southern California Bight. Based on 

 sportfish creel census data, the species was most abundant in the southern part of the Bight, particular- 

 ly around Catalina, San Clemente, and the Coronado Islands. Trawl studies from 1974 to 1984 indicated 

 that California scorpionfish populations varied considerably in abundance, with numbers peaking in 1982. 

 Though the species usually associates with hard substrata, it was abundant over mud about the Palos 

 Verdes Peninsula, site of a major sewage outfall. We think that this anomalous abundance was due to 

 the presence of large numbers of a prey species, the ridgeback prawn, Sicyonia ingentis, which was 

 attracted to the nutrient-rich substrata. 



Female California scorpionfish lived to 21 years, males to 15. Females grew faster than males. Von 

 Bertalanffy age-length parameters for females were L = 44.3, k = 0.13, Iq = -1.9, and for males L 

 = 36.3, k = 0.12, ^Q = -3.86. Over 50% of both females and males were mature at 2 years of age. Males 

 tended to mature at a slightly smaller size. Spawning occurred from May through August, peaking in 

 July. California scorpionfish formed large offshore spawning aggregations in waters deeper than their 

 off-season habitat. Tagging results indicated that fish return to the same spawning area annually. Crabs, 

 primarily juvenile Cancer anthonyi, were the most important food item of fishes inhabiting soft substrata 

 in shallow water. 



The family Scorpaenidae is represented by four 

 genera in the northeastern Pacific— Scorpaena, 

 Scorpaenodes, Sebastes, and Sebastolobus (Esch- 

 meyer et al. 1983). One Scorpaena species, S. gut- 

 tata, the California scorpionfish, is abundant as far 

 north as southern California. 



The California scorpionfish is a medium-sized [to 

 43 cm TL (total length)], generally benthic species, 

 found from central California into the Gulf of 

 California between the intertidal and 183 m (Esch- 

 meyer et al. 1983). It occurs on rocky reefs (often 

 lodged in crevices), although in certain areas and 

 seasons it aggregates over sandy or muddy sub- 

 strata (Frey 1971; present paper). This species is 

 oviparous, producing floating, gelatinous egg 

 masses in which the eggs are embedded in a single 

 layer (Orton 1955). Like others in the genus Scor- 

 paena, California scorpionfish produce a toxin in 

 their dorsal, anal, and pelvic spines, which produces 

 intense, painful wounds. California scorpionfish 

 comprise a minor part of the California sport and 



^VANTUNA Research Group, Occidental College, Moore 

 Laboratory of Zoology, Los Angeles, CA 90041. 



^Marine Resource Branch, California Department of Fish and 

 Game, 1301 West 12th, Long Beach, CA 90813. 



commercial fisheries (Wine and Hoban^, Wine*, 

 Knaggs^, present paper). 



Perhaps because of this relatively small catch, the 

 species has not been the subject of an in-depth life 

 history study. Rather, much of what is known has 

 been gleaned from larger ecological surveys (Table 

 1), in which the species played a minor role. How- 

 ever, California scorpionfish have recently become 

 important in pollution-related studies (Table 1), 

 deriving from 1) its abundance about the Palos 

 Verdes Peninsula (heavily polluted from the Whites 

 Point sewage outfall which services Los Angeles), 

 2) its ease of capture by otter trawl and by hook 

 and line, and 3) its ability to adapt to laboratory 

 aquaria. 



This increased interest has given rise to questions 

 regarding the species' growth rate, age at first 

 maturity, and movements. Our paper details some 



Manuscript accepted September 1986. 

 FISHERY BULLETIN: VOL. 85, NO. 1. 1987. 



^Wine, v., and T. Hoban. 1976. Southern California indepen- 

 dent sportfishing survey annual report, July 1, 1975-June 30, 1976 

 Calif. Dep. Fish Game, 109 p. 



^Wine, V. 1979. Southern California independent sportfishing 

 survey annual report, July 1, 1977-June 30, 1978. Calif. Dep. Fish 

 Game, 100 p. 



^E. Knaggs, California Department of Fish and Game, Long 

 Beach, CA, pers. commun. May 1985. 



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