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International Journal of Marine Science 2013, Vol.3, No.47, 402-407
http://ijms.sophiapublisher.com
406
Table 3 Monthly percentage distribution of various maturity stages for the Omani Indian oil sardines collected during January
1997–September 2008
Maturity stages (%)
Maturity stages (%)
Months
I
II
III
IV
V
Spent
Months
I
II
III
IV
V
Spent
Jan
-
97
21
30
18
30
May
-
05
46
2
7
44
Feb
-
97
11
27
30
31
Jun
-
05
10
13
33
8
38
Mar
-
97
31
22
14
33
Jul
-
05
3
38
55
5
Apr
-
97
43
37
11
8
Aug
-
05
14
7
24
48
7
May
-
97
44
52
4
Sep
-
05
34
37
29
Jun
-
97
6
35
49
10
1
Nov
-
05
18
20
5
48
10
Jul
-
97
27
63
10
Apr
-
06
5
33
13
46
3
Aug
-
97
1
14
55
30
May
-
06
26
26
12
17
19
Sep
-
97
63
14
17
5
1
Jun
-
06
0
10
28
53
10
Oct
-
97
96
4
Sep
-
06
5
10
22
20
29
15
Nov
-
97
7
35
40
18
Dec
-
06
3
40
55
3
Dec
-
97
21
36
19
12
13
Jan
-
07
5
13
55
26
Jan
-
98
7
37
30
25
2
Feb
-
07
13
10
13
13
15
38
Feb
-
98
3
97
Mar
-
07
40
18
5
3
10
25
Jan
-
04
5
7
17
21
50
May
-
07
15
38
10
8
30
Apr
-
04
36
30
33
2
Jun
-
07
11
3
26
37
11
11
May
-
04
53
20
23
3
Aug
-
07
0
10
28
25
38
Jun
-
04
9
38
47
6
Sep
-
07
8
18
25
30
18
3
Jul
-
04
20
44
37
Oct
-
07
8
30
23
18
8
15
Sep
-
04
30
35
35
Dec
-
07
3
40
55
3
Oct
-
04
8
15
38
28
13
Jan
-
08
3
31
31
36
Dec
-
04
2
48
32
18
Apr
-
08
8
28
35
30
Feb
-
05
45
55
May
-
08
15
25
10
13
38
Mar
-
05
5
29
45
21
Jun
-
08
4
13
29
33
18
4
Apr
-
05
23
20
40
18
Aug
-
08
36
41
23
Sep
-
08
5
3
90
3
The relationship obtained between the sex ratio and
total length of the Omani Indian oil sardine is
considered to be reported for the first time in Oman.
The power models (sex ratio = 8.9×10
-6
L
3.79
) for the
1997–1998 data and (sex ratio = 6.7×10
-6
L
6.84
) for the
2004–2008 data are useful in reconstructing the sex
composition from catch data. In addition, this
information is useful for the better fish management
through the application of the sex based stock
assessment models. Similar patterns for sex ratio
versus length were observed in other fishes as well
(Wang et al., 2003; Wei et al., 2006).
Higher abundance and dominance of females in
different months and size classes are an indication of
higher growth rate in the females over the males.
Growth indices for female sardines were found to be
higher than those for males in several studies as found
by Athanassios, Tsikliras and Antonopoulou (2006).
This significant difference in the growth rate between
the sex results in an imbalance in the sex ratio of
sardines caught, which in turn could increase the
difficulty of sardine management in Oman.
During the period 1997–1998, small sardines
dominated the catch (mean weight 34.68 ± 0.41 g)
versus (mean weight 42.44± 0.38 g) for 2004–2008
samples. In addition, the percentage occurrence of the
smaller immature sardines was higher than the larger
mature sardines in 2004–2008 samples. This could be
attributed to the change of sardine prices during the
years. Fifty sardines were sold in pieces for RO 0.3
irrespective of the size. Currently, fishermen sell 40
large sardines for double or even triple the amount
depending on the market, place, and time of the year.
This change in the market price of the sardines led the
fishermen to sort their catch and discard the little ones.
The change in the size distribution also could be