Eggs and Larvae of the Nehu — Tester 
331 
CATCH CONFIDENCE THEORETICAL 
SURVEY RATIO INTERVAL CATCH RATIO 
1 0.1204 0.0961-0.1509 0.0484 
2 0.0558 0.0300-0.1037 0.0151 
3 0.0614 0.0338-0.1115 0.0484 
4 0.0688 0.0552-0.0874 0.0484 
In the above tabulation, the theoretical 
ratios are those for the areas of the net 
mouths: 100 cm. net, 7,854.0 cm. 2; 22 cm. 
net, 380.13 cm. 12.3 cm. net, 118.82 cm.L 
The observed catch ratios differ signifi- 
cantly from the theoretical ratios for all sur- 
veys except the third. The smaller nets (22 
cm. and 12.3 cm.) are relatively more efficient 
than the large net (100 cm.). This is in con- 
trast to the results of Winsor and Clarke, al- 
though the data are not directly comparable 
as they v^ere dealing with motile organisms. 
The exceptionally large ratio in Survey 1 is 
doubtless due mostly to loss of eggs from 
the 100 cm. net when small rips developed, 
as already explained. The reason for the 
larger-than-expected ratios in the other sur- 
veys is less clear: the straining area of the 
large net was relatively greater than that of 
the small nets; the apertures of the mesh in 
all nets were sufficiently small to retain the 
eggs, with the possible exception of that of 
the forward and middle parts of the large net. 
In these parts it is possible, although not 
likely, that eggs could have escaped in an 
end-on position. The efficiency of the large 
net may have been decreased by loss of 
plankton during transfer to containers, or by 
progressive clogging within days, as noted 
in a previous section. 
TABLE 7 
Analysis of Variance of Egg Catches in Surveys 1 to 4 according to Stations, Haul Order, and Nets 
DEGREES OF 
SUM OF 
MEAN 
SURVEY 
SOURCE OF VARIATION 
FREEDOM 
SQUARES 
SQUARE 
1 
Stations (S) 
8 
4.28258 
0.53532 
Haul order (H) 
1 
0.27991 
0.27991 
Nets (N) 
1 
7.60712 
7.60712 
SXH 
8 
1.70812 
0.21352** 
SXN 
8 
0.17259 
0.02157 
HXN 
1 
0.00371 
0.00371 
SXHXN 
8 
0.09480 
0.01185 
2 
Stations 
2 
1.61393 
0.80696 
Haul order 
1 
0.17610 
0.17610 
Nets 
1 
4.71316 
4.71316 
SXH 
2 
0.20601 
0.10300 
SXN 
2 
0.10856 
0.05428 
HXN 
1 
0.00006 
0.00006 
SXHXN 
2 
0.09495 
0.04748 
3 
Stations 
3 
11.85402 
3.95134 
Haul order 
1 
0.05958 
0.05958 
Nets 
1 
5.87432 
5.87432 
SXH 
3 
0.34663 
0.11554 
SXN 
3 
0.13537 
0.04512 
HXN 
1 
0.05907 
0.05907 
SXHXN 
3 
0.11017 
0.03672 
4 
Stations 
8 
3.08473 
0.38559 
Haul order 
1 
0.20672 
0.20672 
Nets 
1 
12.15801 
12.15801 
SXH 
8 
1.00648 
0.12581** 
SXN 
8 
0.19387 
0.02423 
HXN 
1 
0.00283 
0.00283 
SXHXN... 
8 
0.10926 
0.01366 
** Highly significant. 
