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Fishery Bulletin 95(4), 1 997 
Table 1 
Summary of albacore ovaries collected in the Pacific Ocean and preservation treatment used. MFL = Mean fork length. 
Group 
Location 
Date 
Number of 
samples 
Collection Preservation 
purpose method 
A — South Pacific 
New Caledonia 
lat. 21-23°S 
May 1990-Feb 1992 
105 
Control group for oocyte diameter 
Formalin 
long. 164-166°E 
MFL = 90 cm (78-103 cm) 
Tonga 
lat. 16-29°S 
Jan 1990-Feb 1992 
45 
Control group for oocyte diameter 
Formalin 
long. 171-177°W 
MFL = 88 cm (82-102 cm) 
B — North Pacific 
Hawaii 
Jun 1991-Aug 1992 
95 
Preservation effects on weight and oocyte diameter 
within 200-mi EEZ 
MFL = 103 cm ( 96-116 cm) 
Bl 
16 
Left and right ovary of each pair 
Formalin or 
treated differently 
Frozen 
B2 
64 
Formalin 
B3 
15 
Frozen 
C — North Pacific 
U.S. jigboat fishery 
lat. 42-53°N 
Aug 1990-Sep 1990 
60 
Preservation effects on oocyte diameter 
Formalin or 
long. 129-146°W 
MFL = 82 cm (78-87 cm) 
Frozen 
Left and right ovary of each pair treated differently 
Table 2 
Mean oocyte diameter (mm) data by ovary weight (g) and preservation method for albacore collected in North Pacific, n = number 
of fish in sample. 
Mean oocyte diameter (mm) 
Ovary weight (g) 
n 
Formalin 
Frozen 
Percent difference 
(formalin vs. frozen) 
* +/-SE 
Range 
if +/- SE 
Range 
10-19 
19 
0.10 ± 0.004 
0.07-0.14 
0.09 ± 0.003 
0.07-0.11 
10.0 
20-29 
27 
0.11 ± 0.002 
0.09-0.13 
0.10 ± 0.002 
0.08-0.13 
9.1 
30-39 
11 
0.11 ± 0.004 
0.08-0.13 
0.09 ± 0.032 
0.08-0.12 
18.1 
40-49 
2 
0.11 ± 0.000 
0.11-0.11 
0.11 ± 0.002 
0.10-0.11 
0.0 
>50 
1 
0.11 
0.11 
0.0 
Total 
60 
0.11 ± 0.002 
0.07-0.13 
0.10 ± 0.002 
0.07-0.13 
9.1 
significant difference in oocyte diameter ((=0.601, 
df=225, P>0.05) within method of preservation, and 
we feel the effects of preservation are largely the 
source of any differences in measurements. 
Ovaries from immature albacore (<88 cm FL) in 
group C, which had been preserved in 10% formalin, 
were found to have oocytes in the most developed mode 
with a significantly larger mean diameter in compari- 
son with those from frozen samples (7=4.614, df=59, 
P< 0.05). The mean diameter of oocytes preserved in 
10% buffered formalin was, on average, 9.1% larger 
than the mean diameter of frozen oocytes (Table 2). 
In mature albacore >95 cm FL, the mean diam- 
eter of oocytes in the most developed mode within 
an ovary was measured for each side of the ovary 
and compared statistically within group Bl. Oocytes 
preserved in 10% buffered formalin were found to 
have a significantly larger diameter (7=3.581, df=14, 
P<0.05) — 7.1% greater, on average, than the oocyte 
diameter in frozen ovaries (Table 3). 
Thus the mean diameter of oocytes in the most 
developed mode suggested that mean oocyte diam- 
eters of frozen ovaries shrank more than those pre- 
served with 10% formalin. Differential preservation 
effects were reported by Joseph (1963), who looked 
at the effects of Gilson’s fluid (Simpson, 1951) ver- 
sus 4% formalin on oocyte diameter in yellowfin and 
skipjack tuna ovaries. He found that the diameters 
