864 
Fishery Bulletin 96(4), I 998 
Table 3 
Length maturation relationship in male English sole collected during months of gonadal recrudescence, October-March. 
bers represent percentage of the animals in the length class at each testicular stage. 
Mum- 
Length 
(mm) 
Regressed 
Early 
recrudescence 
Late 
recrudescence 
Early 
spermiogenesis 
Spawning 
Spawned out 
n 
<220 
85 
15 
13 
221-230 
6.7 
13 
6.7 
60 
13 
15 
231-240 
13 
6.7 
13 
33 
27 
6.7 
15 
241-250 
6.7 
3.3 
27 
60 
3.3 
30 
251-260 
5.6 
5.6 
0 
47 
39 
2.8 
36 
261-270 
2.9 
2.9 
49 
40 
5.7 
35 
271-280 
4.8 
43 
48 
4.8 
21 
281-290 
6.7 
40 
53 
15 
291-300 
36 
64 
14 
301-310 
38 
50 
13 
8 
311-320 
25 
50 
25 
4 
>320 
10 
10 
10 
70 
10 
ductive parameters were reduced in spawned 
out fish (GSI: 0.8 ±0.1, n=8; 11KT: 83 ±5, n= 8; 
T: 24 ±7, n= 7), and plasma steroid levels in 
spawned out fish were significantly lower than 
levels observed in fish at other stages of tes- 
ticular development. 
Figure 7, A-C, shows the mean levels of re- 
productive parameters in male sole at each 
month of collection. GSI in sole sampled dur- 
ing July was low (0.89 ±0.18, n=6), increased to 
a peak in January (2.6 ±0.7, n= 4), and returned 
to baseline levels in sole sampled in March (0.8 
±0.8, n- 22). Plasma steroid levels were low in 
sole sampled in July (11KT: 890 ±140, rc = 13; T: 
120 ±30, n = 12) even though a few fish expressed 
milt. The levels increased to a peak in Febru- 
ary (11KT: 13000 ±2800, n = 6; T: 1800 ±340, 
n = 14), and decreased in March (11KT: 1300 
±950, n=18; T: 400 ±310, n = 15). Highest levels 
of plasma T and 11KT were found in fish from 
University Point where fish had migrated to 
spawn. A few fish with comparable levels of 
1 1KT were found in March from the residential 
site at Tulalip Bay. 
Discussion 
Typical size-at-maturity for English sole is 260 and 
210 mm TL for female and male sole, respectively 
(Garrison and Miller, 1982). Histological analyses of 
gonads collected in our study showed the smallest 
group of vitellogenic females to be 240-249 mm TL, 
but generally fish less than 260 mm TL were imma- 
ture. Also, among females >260 mm, which were pre- 
sumably old enough to undergo sexual maturation, 
approximately 24% were found in the regressed stage 
even during the peak of the reproductive season. This 
finding is consistent with findings by Johnson et al. 
(1988), in which the percentage of vitellogenic fe- 
males at reference areas during peak recrudescence 
was about 80%. In contrast, males at much smaller 
length (i.e. 195 mm) were maturing, but no spawned 
out males were found at sizes <230 mm, suggesting 
that males <230 mm may not migrate to the spawn- 
ing area. Although fish age was not determined in 
this study, length-at-age relationships determined for 
Puget Sound English sole (Myers et al., 1993) showed 
