International Journal of Marine Science 2016, Vol.6, No.22, 1-14
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Table 1. Summary of descriptive statistics (C.L, C.W, Ch.L, Ab.L, and Ab.W) for
D. blandfordi
at Clifton beach
Male
N
Min
Max
Mean
Median
St. Dev
C.L (mm)
733
1.1
8.9
4.738
4.6
1.5786
C.W (mm)
733
1.5
9.9
5.6699
5.5
1.7077
Ch.L (mm)
733
0.5
8.9
4.0615
3.8
1.6038
Female
N
Min
Max
Mean
Median
St. Dev
C.L (mm)
447
1.3
7.8
4.5159
4.6
1.0215
C.W (mm)
447
2.3
8.5
5.4664
5.5
1.0653
Ch.L (mm)
447
1.2
7.5
4.4074
4.6
1.0183
Ab.L (mm)
447
1.2
7.5
4.4098
4.4
1.0521
Ab.W(mm)
447
1.2
7.3
3.674
3.7
1.0149
Table 2. Summary of descriptive statistics (C.L, C.W, Ch.L, Ab.L, and Ab.W) for
D. blandfordi
at Korangi Creek
Male
N
Min
Max
Mean
Median
St. Dev
C.L (mm)
668
1.3
10.8
5.3823
5.5
1.75
C.W (mm)
668
2.1
12.6
6.4572
6.6
2.0012
Ch.L (mm)
668
0.8
11.1
4.8828
4.9
1.8577
Female
N
Min
Max
Mean
Median
St. Dev
C.L (mm)
532
1.8
8.2
4.7179
4.8
1.0772
C.W (mm)
532
2.3
10.9
5.716
5.7
1.252
Ch.L (mm)
532
1.4
7.7
4.5711
4.7
1.0388
Ab.L (mm)
532
1.6
7.5
4.5632
4.6
1.0757
Ab.W(mm)
532
1
8.1
3.825
3.7
1.0485
The relationship between C.W x C.L of male individuals and C.W x Ab.W of female individuals was positive at both
sites Clifton and Korangi Creek (Figs. 7 and 8 respectively). The equation Log C.L = Log - 0.146 + 1.09 Log C.W (P
< 0.001) for male individuals and Log Ab.W = Log - 0.351+1.23 Log C.W (P < 0.001) for female individuals in
Clifton sample whereas the equation Log C.L = Log – 0.124 + 1.05 Log C.W (P < 0.001) for males and Log Ab.W =
Log - 0.107 + 0.902 Log C.W (P < 0.001) for females in Korangi Creek sample (Figs. 7 and 8 respectively).
There was large variation observed in sex ratio of male and female for
D. blanfordi
at Clifton (1:0.57-1:5.91) and
Korangi Creek (1:0.78-1:1.86). The ovigerous females were captured only in a period of March-July 2007 and in
February 2008 at both Clifton and Korangi Creek (Figs 9 and 10). Individual fecundity of
D. blanfordi
ranged from
140 (C.W=4.0 mm) to 583 eggs (C.W=8.5 mm) at Clifton and 145 (C.W=4.2) to 567 eggs (C.W=9.8 mm) at
Korangi Creek (Tables 3 and 4; Figures 11 and 12).
Fig. 2. Seasonal variation in abundance of
D. blanfordi
at
Korangi Creek of Karachi coast
Fig. 1. Seasonal variation in abundance of
D. blanfordi
at
Clifton beach of Karachi coast
