Lefebvre et at: Reproductive ecology and size-dependent fecundity in Eopsetta jordani 
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Table 1 
Summary information for catches of petrale sole (Eopsetta jordani ) during 2014—2017 off 
California and the Pacific Northwest (Oregon and Washington), including number of sam¬ 
ples by month, mean size in total length (TL), and mean age in years. An asterisk (*) indi¬ 
cates a sample included in fecundity analyses. Standard deviations (SDs) of means are 
given in parentheses. Blank cells indicate that no samples were available. 
No. of samples 
California 
Pacific Northwest 
Month 
2014-15 
2015-16 
2016-17 
2015-16 
2016-17 
August 
10 (7)* 
9 
25 (3)* 
September 
81 (27)* 
8(1)* 
42(11)* 
14 
October 
40 (7)* 
40 (6)* 
December 
12 
39 (1)* 
10(7)* 
January 
20 
1 
10(1)* 
February 
40 
Total 
72 
171 
48 
51 
59 
Size range (mm TL) 
336-555 
330-600 
305-545 
300-520 
280-450 
Mean size (SD) 
441(39) 
487 (47) 
463 (40) 
429 (55) 
442(69) 
Age range (years) 
4-14 
5-20 
4-14 
3-10 
4-15 
Mean age (SD) 
7.7 (2.0) 
10.6(3.5) 
8.0 (2.0) 
6.6 (1.9) 
10.0(3.1) 
No. of samples aged 
72 
147 
30 
40 
20 
factor was applied to account for differences in fresh 
and preserved gonad weights (stage 2: F est =1.02P-3.66; 
stage 3: F est =0.99PW+5.30; F est is the estimated fresh 
weight [in grams], and PW is the preserved weight 
[in grams]). No correction factor was necessary for ovaries 
of macroscopic stages 1, 4, and 5). 
A small piece of tissue was removed from all ovaries for 
histological analysis. Between 2 and 6 weighed subsam¬ 
ples (0.25-1.00 g) for fecundity analyses and 1 unweighed 
sample for archives were collected from stage-2 and -3 
ovaries by gently teasing oocytes from fresh ovarian tissue 
(see the “Fecundity” section below for details). Ages were 
determined from otoliths through the break-and-burn 
technique by the aging lab at the NWFSC in Newport, 
Oregon. Ages were estimated from all otoliths from com¬ 
mercial and WDFW collections; from NWFSC collections, 
ages were estimated only from otoliths of fish that were 
used to estimate fecundity (rc=16). 
Histological analysis 
Ovarian tissue samples were fixed in 10% neutral buff¬ 
ered formalin for at least 48 h before being rinsed in water 
and stored in 70% ethanol. Tissues selected for histological 
analyses were processed according to standard histolog¬ 
ical techniques, by using paraffin as a blocking medium 
and staining and counterstaining sections with hematox¬ 
ylin and Eosin Y (Humason, 1972). All stage-2 (n=142) 
and stage-3 (n= 48) ovaries were selected to determine 
their suitability for inclusion in fecundity analyses. These 
samples, along with haphazardly selected representatives 
of macroscopic stages 1 (n= 12), 4 (n= 12), and 5 (« = 16), 
were used to detail the reproductive cycle of petrale sole. 
Histological sections were examined at 40-250x magnifi¬ 
cation by using a compound microscope. Each ovary was 
assigned an ovarian phase on the basis of the stage of 
the leading oocyte cohort, incidence and state of atresia, 
and presence of postovulatory follicle (POF) complexes 
(Tables 2 and 3). Ovarian phases were based on descrip¬ 
tions of oocyte development in Wallace and Selman (1981) 
and Lowerre-Barbieri et al. (2011), and standard terminol¬ 
ogy suggested by Brown-Peterson et al. (2011) was used 
for them. To examine the size range of oocyte stages, mean 
maximum oocyte diameters were recorded from histolog¬ 
ical slides of 99 individuals: the diameter of the largest 
oocyte of the leading cohort in each of 5 fields of view was 
measured by using an ocular micrometer, and diameters 
were averaged to obtain the mean maximum oocyte diam¬ 
eter (Table 3). Estimates of sizes of hydrated oocytes were 
made from preserved whole tissue mounts from 5 stage-3 
ovarian samples by using a compound microscope and ocu¬ 
lar micrometer (Table 3). 
To verify homogenous ovarian development, histology 
samples were collected and processed from the anterior, 
middle, and posterior portion of blind- and eyed-side 
ovarian lobes (6 total) from 15 females (stage-2 [?i=8] and 
stage-3 [n=7] ovaries). Slides were read without refer¬ 
ence to identification number, ovarian lobe, or location. 
Oocyte stage of the leading cohort was recorded, and his¬ 
tological phase was assigned. Because there were no 
