International Journal of Aquaculture, 2016, Vol.6, No.5, 1
-
14
2
with those of previous studies.
2 Materials and Methods
Living samples of
Liza carinata
were randomly taken monthly during November 2012 to October 2013 from Suez
Bay. Fish were weighed (±0.1 g) on an electronic balance, measured (±0.1 cm) and the ventral surface slit open.
The gonads were separated, weighed and placed in 10% buffered formalin. The stage of gonad maturity was
determined visually following (Abou-seedo and Stephen, 2004). The relationship between the length (L) and
weight (W) of fish was expressed by the equation given by (Pauly, 1082). W = aL
b
, where W = Weight of fish in
(g), L = Total length (TL) of fish in (cm), a = Constant (intercept), b = slope (change in weight per unit change in
length). The “a” and “b” values were obtained from a linear regression of the length and weight of the fish
measured. Length in exponent 3 expressed as a percentage was used to calculate the condition factor estimated
from the relation below:
K= 100 W / L 3 Where, K = Condition factor, W = Weight of fish (g) and L = Length of fish (cm). Gonadosomatic
Index (GSI%), (gonad weight / Gutted body weight X 100) and hepatosomatic Index (HSI%). (Liver weight /
Gutted body weight X 100) were calculated for each fish and all values were averaged monthly.
To calculate fecundity, all available ovaries (56) recognized as III to V were placed in jars with formalin 4%. The
egg mass of each ovary was weighed (w) and four subsamples were taken containing (n) eggs. The total number
of yolked eggs (F) in the ovary (absolute fecundity) was calculated using the formula F= wn / x; where (x) is the
weight of the subsample.
Statistical Analysis
The average of data among treatments was analyzed by one way ANOVA followed by Tukey test using SPSS
software (Version 13). Results are presented as means ±standard error of the mean (SEM).
3 Results and Discussion
3.1 Length – weight relationship for female and male
The length and weight measurements of 718 specimens of male and female
Liza carinata
were used in order to
correctly model the curvilinear relationship between length and weight. The relationship for female and male was
almost strong, but female shows more strong relationship than male. This relationship is usually expressed by the
equation:
W = a L
b
The “a” and “b” values were obtained from a linear regression of the length and weight of fish. The correlation (r
2
)
that is the degree of association between the length and weight was computed from the linear regression analysis:
R = r
2
1) Females
Female
Liza carinata
varied in total length from 10.8 to 18.2 cm and in weight from 11.5 to 73.64 gm, the
estimated length – weight equation for the investigated female species (Figure 1) is:
W = 0.012L
2.946
(R = 0.874 5)
2) Males
Male
Liza carinata
varied in total length from 10.5 to 17.3 cm and in weight from 14.54 to 60.42 gm, the
estimated length – weight equation for the investigated male species (Figure 2) is:
W = 0.034L
2.569
(R = 0.802 4)
