A total of 75 male and female Liza parsia were examined to determine the gonadosomatic index, fecundity and Length- Weight relationship. To analyses feeding habit to match contents of specimens thirty of L. parsia were analyzed in microbiology laboratory. The total length (TL), standard length (SL) and body weight (BW) of the specimens were measured in centimeter (cm). Body weight was recorded by electric balance (OHAUS, 0.0001g-210g) of 0.001 gram (gm) denomination. Eye observation and common morphological symptoms like swollen abdomen and protruded anus was used for identifying the maturity stages. For feeding habit analysis live fish was collected from the Pashur River and shrimp farms.
The weight of ovaries was taken by electronic balance. Weights of both left and right lobes of ovaries ware taken in the same way. Then sample weight was taken from all parts of ovaries from each lobe. Finally the number of eggs was directly counted with a fine needle.
The weight of ovaries was taken by electronic balance. Weights of both left and right lobes of ovaries ware taken in the same way. Then sample weight was taken from all parts of ovaries from each lobe. Finally the number of eggs was directly counted with a fine needle.
F = N x Gonad weight (g) / Sample gonad weight (g)
Where, F is the fecundity and N is the number of eggs in the specimens
Gonadosomatic index: Gonadosomatic Index was calculated by the formula used by Parameswarn et al. (1974) as follows
GSI = W1 (g) / W2 (g) x 100
Where, W1= Wet weight of gonad and W2= Total Wet weight of gonad
Food and feeding habit: Fishes under study were dissected and the stomachs were carefully cut from the rest of the digestive tract. The condition of feed was assessed by the degree of distension of the stomach and expressed as gorged, full, 3/4 full, 1/2 full, 1/4 full, tress and empty. This is known as index of fullness. The volume of stomach content estimated by observation was recorded on absolute scale. The largest volume found in the preliminary study was allocated 100 points, and each of the stomachs as examined was then rated in one of the following categories 0, 3, 6, 12, 25, 50 and 100 points, according to the volume of food present. The stomach contents were emptied into a Petri dish and examined under a binocular microscope with the help of Sedgewick Rafter Counting Cell Slide. Occurrence method was used for the qualitative analysis of food contents.
Length- weight relationship: Then length- weight relationship was calculated by using LeCren’s (1951) formula, as follows:
W = aLb
Where W= weight in g, L= length in cm, a= intercept and b= exponent
The exponential form of relationship in the formula was expressed in the logarithmic form
LogW = Loga + bLogL
In order to derive the arithmetic relationship between fecundity-total length, fecundity-standard length, fecundity-body weight and fecundity-gonad weight, the values of regression co-efficient was estimated by the least square method (Le Cren, l95l) and the co-efficient of correlation was also calculated.