430 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



the intraovarian ova, and hence the ovum dia- 

 meters are also yolk diameters. In figure 2-i 

 yolk-diameter distributions of 343 planktonic sar- 

 dine ova in early developmental stages are shown 

 for comparison with figure 2-h. 



Figure 2-j sliows the ovum diameter distribu- 

 tion of degenerating ova from the ovaries of a 

 sardine taken in May of 1951. None of the San 

 Pedro 1945-46 sardines used in this study were 

 found to be in this condition. 



Clark (1934) grouped developing ova in the 

 largest mode into twelve stages of maturity. As 

 I will have occasion to refer to some of these stages 

 in comparing my observations with those of Clark, 

 I am including a description of these stages: 



lMM.\TrRE 



Stage A; Frequencies with a mode between and 0.2 mm. 



only. 



Maturing (Opaque Eggs) 

 Stage B: Frequencies with the last mode between — 0.22 



and 0.26 mm. 

 Stage C: Frequencies with tlie last mode between — 0.26 



and 0.3-1 mm. 

 Stage D: Frequencies with the last mode between — 0.34 



and 0.44 mm. 

 Stage E: Frequencies with the last mode between — 0.44 



and 0.54 mm. 

 Stage F: Frequencies with the last mode between — 0.54 



and 0.64 mm. 

 Stage G: Frequencies with the last mode between — 0.64 



and 0.74 mm. 

 Stage H: Frequencies with the last mode between — 0.74 



and 0.84 mm. 



f-N- 



o 



10 

 

 20 

 10 

 



20 



10 





 70 



60 



50 



40 



30 



20 



10 





 20 



10 







^ f-l--^' 



n^- wjti 11-- 



Fig. 2-f 

 STAGE "G" 



Estimated number of ova 

 .22-.62mm 86,600 



.58-. 74mm 45,700 



Fig. 2-g 

 STAGE G 



Estimated number of ova 

 .22-.50mm 53,000 

 .66-.7emm 31,000 



Ett=i 



rftrFK-- 



STAGE I 



Estimoted number of ova 



.76-.96mm 20,400 



Fig. 2-h 



^ 



s 



Fig. 2-1 



YOLK DIAMETERS 

 eggs from plankton 



^v- 



A 



STAGE 



Fig 2-1 



LNt 



.4:?T-r 



^l:>4^T:i:JbJfe^ 



.22 .26 .30 .34 .38 .42 .46 .50 .54 .58 62 .66 .70 74 78 .82 .86 .90 .94 .98 

 OVUM DIAMETER IN MILLIMETERS 



Figure 2-f, g, h, i, j. — Sardine ovum diameter frequencies. 



