LOVE and WESTPHAL: GROWTH AND FOOD HABITS OF OLIVE ROCKFISH 



Table 3. — Mean back-calculated total length (centimeters) ± 95% confidence intervals at successive annuli for male olive rockfish 



captured off Avila during 1972-77. 



Table 4. — Mean back-calculated total length (centimeters) ± 95% confidence intervals at successive annuli for female olive rockfish 



captured off Avila during 1972-77. 



we did capture females to 61.9 cm and males 

 to 50.2 cm. 



No marked Lee's Phenomenon was noted, 

 though it is found in other rockfishes (Chen 1971; 

 Miller and Geibel 1973). A possible explanation is 

 that fish older than age 12 were not used in back 

 calculations, and since some members of the 

 species live to at least 25 yr, the phenomenon may 

 not be apparent until older fish are examined. 



Length-Weight Relationships 



A total of 312 males and 304 females were 

 weighed and measured. The relationships be- 

 tween total length and weight seemed to fit the 

 relationships W = aL^, where W = weight in 

 grams and L = total length in centimeters, and 

 a and b are constants. The values of a and 

 b were determined using logio transformation and 

 fitting the values to a straight line by least 

 squares. Females tended to be heavier at a given 

 length (analysis of variance, F = 15.23, P<0.01) 

 (Figures 4, 5). To test whether this difference was 

 an artifact caused by the larger female gonads, 

 we subtracted gonad weight from body weight, 

 generated the length-weight relationships for 



each sex and tested these between sexes. Again, 

 females were heavier at length (analysis of vari- 

 ance, F = 10.18, P< 0.01). 



Maturation and Reproduction 



Insemination and Birthing Season 



Larval release occurred from December through 

 March, peaking during January (Figure 6). Spent 

 females were most prevalent during early spring, 

 followed by a June peak in resting fish and a 

 September-October peak in mature individuals. 

 Fertilized fish were found from November through 

 January. Ovary weights remained essentially 

 constant during the spring and summer (Figure 

 7), averaging perhaps 0.3% of body weight, occa- 

 sionally as little as 0.1%. Then, during the winter 

 and spawning season, ripe ovaries averaged 13.8% 

 of body weight (maximum 20.7% , minimum 2.3%). 



Testes sizes (based on the gonad index) were 

 relatively constant during spring and early sum- 

 mer, though they began to increase in size a month 

 or two earlier than did the ovaries of females 

 (Figure 7). During the constant period, they re- 

 mained at minimum size, about 0.1% of body 



537 



