FISHERY BULLETIN: VOL. 83, NO. 2 



and Goldberg (1980), i.e., presence of hydrated 

 eggs (imminent spawning), day or new post- 

 ovulatory follicles (spawning on the night of cap- 

 ture), and 1-d-old postovulatory follicles (spawn- 

 ing on the night before capture). We also include 

 the number of females judged to have inactive or 

 immature ovaries with no evidence of atresia. All 

 data on the incidence of reproductive states are 

 given in Table 4. In the discussion that follows we 

 select and regroup these data in various fashions 

 to test hypotheses and document trends. 



Incidence of Spawning in Atretic Females 



An important assumption underlying interpre- 

 tation of ovarian atresia is that the spawning sea- 

 son has or is going to cease, in other words, the 

 probability of spawning in females with atretic 



ovaries would be expected to be low. To test this 

 assumption we selected from Table 4 the females 

 which had alpha stage atresia of yolked oocytes 

 (atretic states 1 and 2) or yolked oocytes without 

 alpha atresia (atresia state 0) and calculated the 

 percentage of these females that had hydrated 

 oocytes, new (day 0) postovulatory follicles, and 

 1-d-old postovulatory follicles. Of the females 

 classed in atretic state 1 (females with <50% of the 

 yolked oocytes in alpha stage of atresia), 14% 

 showed evidence of recent or imminent spawning 

 (postovulatory follicles or hydrated oocytes); 29% 

 of the females without atresia showed evidence of 

 spawning (Table 5). Only 1% of those in atretic 

 state 2 (females 50% or more atretic yolked oo- 

 cytes) had recently been reproductively active. 

 That 1.8% of females in atretic state 1 had hy- 

 drated eggs and 3.7% had age d postovulatory 



TABLE 4. — Numbers of female northern anchovy in various atretic and reproductive states 



northern California 



'Atretic state = no alpha stage atresia of yolked oocytes. 



state 1 = alpha stage atresia of yolked oocytes present but • 50% oocytes affected, 

 state 2 = alpha stage atresia of yolked oocytes present, 50% or more oocytes affected 

 state 3 = no yolked oocytes present and beta stage atresia present. 



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