FECtJNDITi' OF THE PACIFIC SARDINE 



447 



state of (levelopment of the ovaries of the fish 

 above 175 nun. in k'lifitli in hniar period 322 (mid- 

 Novemher). Clark (1934:22) states that, " * * * 

 adolescent fish may start to mature eggs but these 

 eggs may fail to reach a ripe state and eventually 

 degenerate. Such a condition has been claimed 

 for the hake by Hickling (1930), but we have not 

 been able either to prove or disprove the possi- 

 bility for tie sardine." As no samples are avail- 

 able for tlie 1946 spawning season after February 

 27, tiie ultimate fate of the ovarian ova of these 

 smaller sardines cannot be determined. If the 

 presence of yolked ova in the ovary is the criterion 

 of maturity, all fish more than 175 mm. in length 

 and 31 percent of the fish under 175 mm. in lengtli 

 from the samples of Februarj- 21 and 27 had 

 attained maturity. If a maximum ovum diameter 

 exceeding 0.40 millimeters (i. e., the maximum 

 ovum diameter attained by any fish in the samples 

 of November 10 and 13, when the ovaries are 

 "resting") is the criterion of maturity, all fish 190 

 mm. or more in length, 82 percent of the fish 175 

 to 189 mm. in length and none of the fish 174 mm. 

 or less in lengtii from the samples of February 21 

 and 27 had attained maturity. 



AGE AT FIRST MATURITY 



Numbers and percentages of sardines at each 

 of three maturity stages for each age group and 

 each lunar period are presented in table 17. If 

 the presence of yolked ova in the ovary is the 

 criterion of maturity, 28 percent of the one-year- 

 old fish and 100 percent of the two-year-old and 

 older fish were maturing in lunar period 326 

 (samples of February 21 and 27). But the pres- 

 ence of yolked ova in the ovaries may not neces- 

 sarih' mean that a fish will develop and eventually 

 spawn those ova. Actually the one-year-old fish 

 were less advanced in respect to ovarian develop- 

 ment in lunar period 326 (samples of February 21 

 and 27) than the two-year-old and older fish were 

 in lunar period 322 (samples of November 10 

 and 13). 



In any case the one-year-old fish taken by the 

 commercial fishery cannot be considered repre- 

 sentative of the one-3'ear-old fish in the population 

 at large. One-year-old sardines are not often 

 taken by the commercial fishery, and those tliat 

 are taken are undoubtedly the larger specimens 

 of that age group. 



Table 17. — Age at first maturity 



