International Journal of Marine Science 2016, Vol.6, No.45, 1-7
3
The estimates of the constants ‘a’ and ‘b’ were obtained by the method of the least square.
The data collected are also considered for biological investigations viz., sex ratio, maturation, spawning, food and
feeding habits of the species using standard methodologies. The stomach contents of 52 specimens of glow fish
caught during Dec’2000 from east coast were cut open and analyzed to understand the major food items of the species.
Results and Discussion
A better description of length frequency / survey data, the number caught per trawl haul is often obtained,
assuming the so-called “Gussian Distribution”. Table -1&1(a); Fig -1&1(a) show the theoretical frequencies with
observed frequencies, as can be seen, theoretical frequencies give a fair fit to the observed length-frequencies.
This picture is often noticed, when recording length-frequencies of the fish, originating from one cohort i.e., fish
of the same age, as seen in the present study. The mean length of the species observed to be 8cm and 9.5cm of set
observations from east and west coast of India respectively.
The relationship between total length and other body measurements was found to be highly correlated, Table -2 &
Fig.2, the coefficient of determination (r
2
) varied from 0.6999 to 0.991. The coefficient of determination (r
2
) is an
indicator of the goodness of fit it of regression equation to the observed data. The closer it is to 1, the better is the
fit. In most of the regression viz., Standard length, Fork length, Body depth, coefficient of determination was very
close to 1, indicating that these characters, under study can be efficiently estimated based on the total length as
independent variable (X) and regression of different relevant morphometric characters viz., pre-orbital length, eye
diameter and inter-orbital length on head length was not found highly correlated. The coefficient of determination
varied from 0.6999 to 0.858 (Table-2) the character pre-orbital lengths, coefficient of determination being close to 1,
on the head length as independent variable (X) may yield estimate based on head length as independent character (X).
The morphometric relationships (Table-2) revealed that in respect of total length, the fork length grows faster
(b=0.87) than standard length (b=0.81), whereas, body depth grows faster (b=0.27) than head length (b=0.22) and
length of I
st
dorsal fin grows faster (b=0.13) than II
nd
dorsal fin (b=0.11), in respect of head length as independent
character (X), revealed that the pre-dorsal length grows faster (b=0.48) than the inter-orbital length (b=0.27) and
the eye diameter (b=0.31).
Table – 1 Mean size of fish against theoretical & observed frequency caught along west coast
Mean size(cm)
Theoretical (f)
Observed (f)
5
0.00611227
1
5.5
0.0441448
1
6
0.255
3
6.5
1.1781
9
7
4.35317
6
7.5
12.8651
18
8
30.4088
45
8.5
57.4871
36
9
86.9208
93
9.5
105.114
107
10
101.666
102
10.5
78.6459
79
11
48.6584
50
11.5
24.0781
16
12
9.52946
15
12.5
3.01645
2
