Bobko and Berkeley: Maturity, ovarian cycle, fecundity, and parturition of Sebastes melanops 



423 



250 



300 



350 400 



Fork length (mm) 



450 



500 



Figure 3 



Logistic regression model for the estimated percentage of sexually mature 

 female black rockfish as a function of fork length, with associated observed 

 percent mature at 10-mm length intervals. 



range showed no evidence of differences in 

 slopes among the years 1996-98 (P=0.161). 

 ANCOVA also showed no significant difference 

 in elevations (P= 0.632), indicating no annual 

 effect and allowing one model to be fitted to 

 the pooled data (Fig. 6). Absolute fecundity 

 for females with fertilized eggs ranged from 

 299,302 embryos for a 6-year-old to 948.152 

 embryos for a 16-year-old. Because of the low 

 number of females with developing embryos 

 collected in 1996 and 1998, 19 and 4 females, 

 respectively, and based on the results of prefer- 

 tilization females, all data were pooled and 

 fitted with one model (Fig. 7). Although we 

 were able to pool the data for all years for 

 fecundity-age regressions for both prefertiliza- 

 tion females and fertilized females, there was 

 evidence of interaction (i.e., unequal slopes) 

 between stage-specific absolute fecundity and 

 age (2-tailed t-test, P=0.020) requiring sepa- 

 rate linear regressions to be fitted to the data 

 (Fig. 8). 



Similar to the ANCOVA results for abso- 

 lute fecundity, there were no differences in 

 slopes or elevations for relative fecundity for 

 prefertilization females for the years 1996-98 

 (Table 4). Again, based on the results of the 

 ANCOVA for prefertilization females and due 

 to the low number of fertilized females collected 

 and 1998, all relative fecundity data for femal 

 fertilized eggs were pooled. Unlike the results 



1992 



1994 



1996 

 Year 



1998 



2000 



Figure 4 



Estimated percent maturity for recreationally landed female black 

 rockfish from Newport, Oregon, based on our logistic regression model 

 of fork length on maturity. Data were from regular random summer 

 port sampling conducted by the Oregon Department of Fish and Wild- 

 life from 1992 through 2000. 



in 1996 relation between absolute fecundity and age there was 



es with no evidence of interaction (i.e., unequal slopes) between 



for the stage-specific relative fecundity and age (2-sided f-test 



