WYLLIE ECHEVERRIA: REPRODUCTION OF CALIFORNIA ROCKFISHES 



Table 7.— Reproductive seasonality for Sebastes from central 

 California collected 1977-84. Listed by taxonomic order (Barsukov 

 1981). 



Principal month(s) of 



Species of 

 Sebastes 



spermato- 

 genesis 



fertil- 

 ization 



parturi- 

 tion 



Feb. 

 Jan. 

 Feb. 

 Feb. 

 Feb. 



Females are exposed to changing environmental fac- 

 tors from year to year, so flexibility in the timing 

 of their greatest reproductive involvement may be 

 advantageous. The apparent flexibility of the period 

 between mating and larval extrusion may be a mech- 

 anism to optimize reproductive success. A long and 

 variable period of larval extrusion is exhibited by 

 the rockfish group (Figs. 8-10). The evidence of two 

 spawnings per season have been reported for 5. 

 paucispinis (Moser 1967a), S. ovalis, and S. con- 

 stellatus (MacGregor 1970). Multiple broods are in- 

 dicated by the presence of eyed larvae undergoing 

 resorption in the ovary concurrently with vitelloginic 

 eggs at least 0.4 mm in diameter. During the years 

 and throughout the area of this study, evidence of 

 multiple broods was rare: only one 5. paucispinis 

 gonad showed evidence of a multiple brood. Moser' s 

 (1967b) detailed description of the histology of multi- 

 ple broods indicates the development and extrusion 

 of a second brood follows within 2 months of the 



40 

 30 

 20 

 10 

 O 



40 

 30 

 20 



10 



o 



1981 



44 147 



128 83 



WM^ " 



J2^_ 



DEC JAN 



FES MAR 



NOV DEC 



NOV DEC JAN FEB MAR APR 



MAR APR 



NOV DEC JAN FEB MAR APR 



Sebastes entomelas 



Figure 8.— Percent of mature female Sebastes entomelas contain- 

 ing eyed larvae for the reproductive months during 1981-85. Total 

 number of mature females observed are indicated over bars. 



first. In this study, two distinct seasons of larval ex- 

 trusion, December and June, were noticed in 5. 

 auriculatus sampled from a limited area (Pt. Reyes- 

 Half Moon Bay) (Table 6) in north-central Califor- 

 nia. The entire reproductive sequence in Sebastes 

 seems to reflect a plasticity for reproduction that 

 may enable the individual to respond adaptively to 

 environmental factors. 



The consequences of the reproductive biology in 

 Sebastes include the absence of strong spawning 

 pulses, the possibility of multiple mating of males, 

 and flexibility in the timing of fertilization. Ap- 

 parently mating is not restricted to a short period 



245 



