Love and Johnson: Life history of Sebastes rastrelliger and 5. auriculotus 



107 



0.9 -1 



0.6- 



r9 



Grass Rockfish 



O Male 



X Female 



* 



Jan Mar May Jul Sep Nov 



CO 



O 

 » 



3 



B 



0.8- 



0.6- 



0.4- 



0.2- 



rIO 





Brown Rockfish 



O Male 



X Female 



^-^:^-.-^-.' 



-6 



-4 



-2 



I I I I I I I I I I r 



Jan Mar May Jul Sep Nov 



Month 



Figure 6 



Seasonal changes in the gonosomatic index (GSI-gonad weight as a percent of 

 total body weight) of male and female grass rockfish iSebastes rastrelliger) and 

 brown rockfish {Sebastes auriculatus). No samples of grass rockfish were taken 

 during November and no samples of male brown rockfish were taken in Febru- 

 ary and September. Vertical lines indicate 95'7t confidence intervals of the mean. 



Along the northeast Pacific, the vast majority of 

 rockfish spawn in the late winter and early spring 

 and, as with length and age at maturation, many 

 rockfish species exhibit a latitudinal trend in spawn- 

 ing season. Parturition often starts earlier or is more 

 prolonged (or both) in the southern part of a species' 

 geographic range (O'Connell, 1987; Wyllie Echever- 



ria, 1987; Barss, 1989; Love et al., 1990). The spawn- 

 ing season for brown rockfish from Puget Sound to 

 southern California appears to follow this pattern. 

 Spawning occurs in Puget Sound in June (Washing- 

 ton et al.''), in December-January and May-June in 

 northern-central California (Wyllie Echeverria, 1987) 

 and in January-August in southern California. 



