Egg and Larva Production of Nehu — Tester 
37 
TABLE 2 
Geometric Mean (G.M.) Egg and Larva Counts and Arithmetic Mean Temperatures (°C.) 
AND CHLORINITIES (p.P.M.) ON A MONTHLY BASIS 
MONTH AND YEAR 
EGGS 
LARVAE 
TEMPER- 
ATURE 
CHLORINITY 
Log 
(G.M. 4- 1) 
G.M. 
Log 
(G.M. + 1) 
G.M. 
9/50 
1.0223 
9.53 
0.1129 
0.30 
26.7 
19.41 
10/50 
0.8504 
6.09 
0.2924 
0.96 
26.4 
19.50 
11/50 
0.4855 
2.06 
0.1534 
0.42 
25.0 
19.06 
12/50 
0.9485 
7.88 
0.3331 
1.15 
22.4 
18.25 
1/51 
0.9234 
7.38 
0.1996 
0.58 
22.8 
19.07 
2/51 
0.9289 
7.49 
0.3280 
1.13 
22.9 
18.98 
3/51 
0.7028 
4.04 
0.2305 
0.70 
23.1 
17.85 
4/51 
0.8264 
5.70 
0.1988 
0.58 
24.4 
18.49 
5/51. 
1.8148 
64.30 
0.5071 
2.22 
25.8 
18.87 
6/51 
1.4007 
24.20 
0.7074 
4.10 
26.8 
19.04 
7/51 
2.3013 
199.10 
0.7487 
4.61 
26.7 
19.18 
8/51 
1.8714 
73.40 
0.5842 
2.85 
27.0 
19.24 
9/51 
1.2416 
16.40 
0.5409 
2.47 
27.4 
19.27 
10/51 
0.7202 
4.25 
0.2013 
0.59 
26.3 
19.11 
11/51 
0.2159 
0.64 
0.0957 
0.25 
24.6 
19.09 
12/51 
0.1403 
0.38 
0.1746 
0.50 
23.2 
18.65 
1/52 
0.0334 
0.08 
0.0576 
0.14 
22.2 
18.73 
2/52 
0.0251 
0.06 
0.1401 
0.38 
22.9 
18.92 
3/52 
0.1453 
0.40 
0.1357 
0.37 
22.4 
19.26 
4/52 
0.7286 
4.35 
0.2497 
0.78 
23.4 
19-30 
5/52 
0.2177 
0.65 
0.2182 
0.65 
23.9 
18.98 
6/52 
0.7278 
4.34 
0.1310 
0.35 
24.6 
19.25 
7/52 
1.6201 
40.70 
0.5042 
2.19 
25.5 
19.29 
8/52 
1.7984 
61.87 
0.2257 
0.68 
26.2 
19.29 
egg production, this cannot be established 
as a conclusion from the present data. 
Figure 2b shows that the larva count also 
varies seasonally with a high production in 
the summer and a low production in the 
winter months. As might be expected, there 
is high correlation between the log mean 
monthly egg and larva counts (r = 0.818; 
P < 0.01). 
Mortality 
When the eggs were counted, they were 
segregated into three categories— "normal,” 
"damaged,” and "agglutinated” — according 
to criteria established by Tester (1951: 325- 
326). The damaged eggs, with the inner mem- 
brane ruptured and the embryo shattered, 
were assumed to have suffered mechanical 
injury during capture. It was suggested that 
the agglutinated eggs, in which the yolk and 
embryo had disintegrated into a whitish mass, 
may have been dead before capture. 
The numbers and percentages of eggs in 
the three categories, segregated according to 
months, are shown in Table 3. From the gross 
data, the (weighted) percentages of normal, 
damaged, and agglutinated eggs are respect- 
ively 46.2, 32.2, and 21.6. These may be 
compared with similar data collected in 1949 
and 1950—48.4, 47.1, and 4.5— recalculated 
