112 
Fishery Bulletin 99(1) 
Advanced Yolked 
Residual Chorion Oocytes . 
Tissue 
0.3 mm 
Figure 2 
Histological section of a yellowfin sole (Limanda aspera ) ovary with advanc- 
ing yolked oocytes and remnants of chorion tissue leftover from previous 
spawning. The 38-cm-TL female was captured 17 June 1993 at a bottom 
depth of 27 m. The yolked oocytes averaged 0.31 mm in diameter, well below 
the mean diameter of yolked oocytes from spawning individuals (>0.44 mm). 
Table 2 
Occurrence of oocyte stages, postovulatory follicles, and other postspawning remnants within immature, maturing, hydrated, 
spawning, and spent yellowfin sole (Limanda aspera ) ovaries. Histological examination of ovary cross sections. 
Oocyte stage or 
intra-ovarian 
structure 
Ovary maturity code 
Total 
fish 
Immature 
(1) 
Maturing 
(2) 
Hydrated 
(3) 
Spawning 
(4) 
Spent 
(5) 
Early perinucleus 
102 
415 
75 
23 
152 
Late perinucleus 
58 
415 
75 
23 
151 
Partially yolked 
8 
349 
17 
7 
82 
Advanced-yolked 
0 
409 
72 
23 
0 
Migratory nucleus 
0 
63 
72 
21 
0 
Hydrated-unovulated (HY) 
0 
0 
75 
3 
0 
Ova 
0 
0 
0 
23 
0 
Postovulatory follicles 
0 
13 
50 
19 
40 
Atretic-HY 
0 
0 
0 
0 
21 
Atretic ova 
0 
7 
9 
1 
52 
Residual chorion tissue 
0 
15 
1 
0 
29 
Number of fish 
102 
415 
75 
23 
152 
767 
(mean AY diameters=0.27 mm), to those that contained 
AY oocytes near maximum size (mean AY diameter=0.43 
mm). These ovaries did not contain POFs or MN stage 
oocytes; therefore ovaries were not advanced enough for 
there to be recent spawning from the existing AY standing 
stock. 
It is possible that these fish had already spawned at 
least one series of batches, were spent, and were readying 
