International Journal of Marine Science, 2016, Vol.6, No.24, 1-8
6
Table 4: Sex ratio and Chi
2
analysis of fish species from Badagry creek, Nigeria
S/N
Fish species
Abundance
Chi
2
Male Female
N
sex ratio
X
2
cal
X
2
tab
1
Chrysichthys nigrodigitatus
70
52
122
1:0.74
2.66
3.84
2
Marcusenenius senegalensis
10
18
28
1:1.8
2.29
3.84
3
Tilapia zilli
103
96
199
1:0.93
0.25
3.84
4
Chrysichthys auratus longifilis
56
56
112
1:1
0.00
3.84
5
Pomadasys peroteti
22
35
57
1:1.59
2.96
3.84
6
Tilapia guinensis
48
37
85
1:0.77
1.42
3.84
7
Pomadasys jubelini
20
24
44
1:1.2
0.36
3.84
8
Gymnarchus niloticus
14
22
36
1:1.57
1.78
3.84
9
Sarotherodon melanotheron
21
14
35
1:0.67
1.40
3.84
10
Tilapia mariae
25
41
66
1:1.64
3.88
3.84
11
Oreochromis niloticus
28
35
63
1:1.25
0.78
3.84
12
Bathygobius soporator
61
100
161
1:64
9.45
3.84
478
530
1008
1:1.1
2.68
3.84
Discussion
From the length- weight relationship (b ranging from 0.19 – 15.59) when compared with b values 2.79- 3.21
reported by Fafioye and Oluajo (2005), who studied the length weight relationship of five species in Epe Lagoon;
2.61 – 3.25 recorded by Agboola and Anetekhai (2008), where they studied the length-weight relationship of 35
fish species from Badagry creek and 2.01 – 2.99 recorded by Kumolu-Johnson et al. (2010) on length – weight
relationship of Ologe lagoon, the creek could be said to support a wide range of species exhibiting different
growth patterns. All the fish species showed positive allometric growth (b > 3) except
G. niloticus
(b=1.19) and M.
senegalensis (b=2.12) which shows negative allometric growth i.e. b = 3.
Pomadasis jubelini
showed an isometry
growth (b approximately 3). When the value of the regression coefficient b showed that the pattern of growth is
negative allometry (b < 3) it indicates that fish are lighter than their body length (Wooten 1998) which implies
poor growth of length than weight, but a positive allometric growth (b > 3) favours weight than length.
Marcusenius senegalensis
showed a negative allometric growth having b value of 2.12. Chrysichthys longifilis
also showed a different growth pattern having a regression coeffiecient of 7.5 indicating positive allometric
growth. The length-weight relationships of the grunters Pomadasys jubelini and Pomadasys peroteti reflected an
isometric and positive allometry growth respectively. The value of the regression coefficient b showed that the
pattern of growth was positive allometric (b < 3) for P. peroteti and issometric for P. jubelini. It can be inferred
Figure 12: Length-weight relationships in
Oreochromis
niloticus
from Badagry creek.
Figure 13: Length-weight relationships in
Bathygobius
soporator
from Badagry creek.
