International Journal of Aquaculture, 2015, Vol.5, No.31 1
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Table 4 Monthly Weight (Gm) of Selected Fish Species from Doma Dam
Months
H. Breves
A. dentex
B. leuciscus
H. foskali
P-value
January
103.67 + 6.84
a
100.00 + 29.50
a
13.41 + 0.53
c
86.25 + 4.21
b
0.031
February
100.50 + 4.50
b
130.00 + 14.90
a
15.86 + 0.59
c
88.55 + 9.76
b
0.001
March
107.50 + 2.50
b
126.70 + 24.10
a
14.41 + 0.45
c
89.90 + 6.48
b
0.001
April
91.25 +1.25
b
143.8 +21.20
a
13.36 +0.62
c
130.00 +20.50
a
0.001
May
110.00 +10.00
a
86.30 +13.10
b
16.59 +0.69
c
98.10 +11.60
b
0.021
June
90.00 + 17.30
b
224.80 + 44.20
a
18.64 + 0.33
c
83.25 + 5.77
b
0.003
July
93.30 + 16.70
a
96.60 + 19.70
a
10.00 + 0.00
b
96.80 + 5.60
a
0.001
August
80.00 + 10.60
b
113.80 + 21.00
a
12.14 + 0.49
c
99.50 + 7.10
b
0.002
September
83.30 + 16.70
c
106.50 + 24.40
a
12.82 + 0.49
d
99.50 + 8.14
b
0.001
October
52.50 + 1.44
b
95.00 + 32.3
a
15.23 + 0.25
c
93.50 + 8.47
a
0.002
November
120.00 + 0.00
a
87.00 + 10.20
b
13.91 + 0.42
c
117.50 + 16.60
a
0.021
December
112.50 + 7.50
a
114.10 + 20.10
a
14.50 + 0.35
c
80.60 + 7.42
b
0.002
Weight
119.40 + 7.81
a
14.24 + 0.19
c
94.60 + 3.62
b
96.93 + 3.005
b
0.01
Mean in the same column with different superscript differ significantly (P<0.05)
important parameter for discrimination of six
population of African catfish in Turkey. Eyo (2003)
reported that among four
Clarias species
(
Clarias
ebriensis, C. albopunctatus, C. gariepinus
and
C.
anguillaris
), congeneric differences occurred in pectoral
fin base length and frontal width, pelvic fin base
length, Pectoral spine height, dorsal fin height,
maxillary teeth band width, premaxillary teeth
band depth, frontal, fontenelle length, internasal space,
pelvic fin-anal fin space and prenasal barbell length,
and in 6 residual characters namely Total Length,
prepectoral length, pectoral fin base, length, dorsal fin
base length, outer mandibular barbel space and eye
diameter. Specific differences among Distichodus
species studied by Nwani and Ude, (2005) reveals that
pelvic fin height, dorsal fin height, anal fin height,
pectoral-pelvic fin space, pelvic anal fin space, head
length and caudal peduncle depth were of significant
taxonomic importance in discriminating all the studied
Distichodus species. Nevertheless, in general, fishes
demonstrate greater variance in morphological traits
both within the same species or different species or
between populations than other vertebrates and reflect
differences in feeding environment and habit, prey
types, food availability or other features (Dunham et
al., 1979; Allendorf, 1988; Thompson, 1991; Wimberger,
1992). It is also important to note that Among the
principal morphological variables that aid in the
discrimination this species and populations, some are
related to feeding habits while the others are to
swimming capacity and maintenance of the fish in the
water column.
Plots of canonical discriminant functions 1 of the
morphometric measurements in this study clearly
showed a complete overlap between
H. breves
and
H.
foskali
and a partial overlap with
A. dentex
and
separate however from
B. leuciscus
. However, plots of
canonical discriminant functions 1 for mer istic
count shows overlap of
A. dentex,
B. leuciscus
and
H. breves
and completely separated from
H. foskali
.
Overlapping variation in morphometric characters
lead to great difficulty in identifying different stocks.
Jerry and Cairns (1998) indicated that phenotype of an
individual is a manifestation of its underlying genotype,
as expressed in the local environment during
development. Consequently, individuals of different
species that develop and mature in the environment
or area would be expected to share a simi lar
phenotype, as they are likely to experience common
environmental and genetic influences (Chambers,
1993). Hence the noticeable overlap among different
species for morphometric and meristic count in this
study might be explained by this. Vidalis et al. (1994)
had argued that meristic characters may follow a
predetermined variability at a very narrow range,
and divergence of the meristic counts from a standard
