FISHERY BULLETIN: VOL. 79, NO. 3 



75 - ,— 

 50 - 

 25 



75 



50 



25 



75 



50 



I- 25 



75 



50 



25 



SPENT 



J F M A M J J li S N 



RIPE 



D 



jTTTTTTTTTTT 



FERTILIZED 



J F M A M J J A 



Jlj 



n 



MATURE 



J F M A I J J A 8 11 



75- 



50 



25 



RESTING 



J F M A M J J A S N D 

 MONTH 



Figure 6. — Percent composition by month of five gonad condi- 

 tion stages for female olive rockfish taken off Diablo Cove, 

 1972-77. Resting refers to that period before egg development, 

 vitellogenesis occurring during the maturing stage, which is 

 terminated by the fertilized stage. Eyed larvae, which define 

 ripe gonads, are extruded and the gonads are called spent. 



California, olive rockfish matured at 17-22 cm TL. 

 This is considerably smaller than fishes taken off 

 Diablo Cove. Unpublished data by Love (1978) 

 indicated that olive rockfish off Santa Barbara (in 

 southern California) mature at the same length as 

 fishes farther north. It is possible that Limbaugh 



liii FEB mill APR Mr JUKE m m sept oci iov W 

 m\i 



Figure 7. — Seasonal changes in the gonosomatic index (GSI — 

 gonad weight as a percent of total body weight) of male and 

 female olive rockfish. Vertical lines indicate 95*^ confidence 

 intervals of the mean. 



270 2aO 29.0 3a0 31.0 22J0 33-0 34.0 35.0 36.0 37.0 3a0 39X) 

 TOTAL LENGTH (CM) 



Figure 8. — Length-maturity relationship in 331 female and 

 318 male olive rockfish collected off Diablo Cove, 1972-77. 



mistook prereproductive individuals, whose go- 

 nads do swell and color slightly, for mature fish. 



Age of first maturity varies widely among 

 rockfish species. At one extreme, S. emphaeus 

 matures at2-4yr (Moulton 1975); S. umbrosus, S. 

 ensifer (Chen 1971), and S.jordani (Phillips 1964) 

 at 3 yr; while the others, S. chlorostictus, S. 

 rosenblatti, and S. constellatus mature at about 10 

 yr (Chen 1971) and some stocks of S. alutus do not 

 mature until 11 yr or later (Gunderson 1977). 

 Modal period for first reproduction seems to be 

 about 4-7 yr for most species (Phillips 1964; Patten 

 1973; Miller and Geibel 1973). 



540 



