HUNTER and GOLDBERG SPAWNING INCIDENCE OF NORTHERN ANCHOVY 



Table l. — Results of blind classification* (number of females) of 

 postovulatory follicles of female northern anchovy spawned in 

 the laboratory. 



'Elapsed time from spawning was unl<nown to classifier 



day 1 postovulatory follicles (95% C.I., Table 2). A 

 normal-log negative binomial distribution 

 {Johnson and Kotz 1970; ZweifeF) was used to 

 estimate confidence intervals for the mean inci- 

 dence of hydrated eggs and new postovulatory fol- 

 licles because it gave a better fit to the data dis- 

 tribution than did the binomial distribution (Fig- 

 ure 3). 



RESULTS 



Sexual Maturity 



All sea samples were classed into the above 

 categories. The mean incidence for each category 

 was calculated without regard to the classification 

 uncertainties reported in Table 1. Confidence in- 

 tervals for mean incidence for each reproductive 

 state were calculated for the February set of sam- 

 ples but not for those taken in March or September 

 because these sets contained only three or four 

 samples. The normal approximation of the bino- 

 mial distribution was used to estimate the 

 confidence interval (C.I.) for the mean incidence of 



All females taken in February and March were 

 mature, but only 67''/ of those taken in September 

 were mature. No relation existed between repro- 

 ductive activity and length in the females 

 examined. Twelve females taken in February in 

 southern inshore stations ( Figure 1 ) were < 90 mm 

 standard length (SL), which is smaller than any of 



'Zweifel, J. R. 1978. Confidence intervals for the mean 

 when sampling from natural environments. Unpubl. man- 

 user,, 10 p. Southwest Fisheries Center, NMFS. NOAA, P.O. Box 

 271, La Jolla. CA 92038. 



Table 2.— Reproductive state' of female northern anchovy collected off southern California in 



February 1978. 



'Immature stale not included in table because all females were mature 



^95°'o confidence mten/als for mean percent of females in each reproductive class 



645 



