345 
Eggs and Larvae of the Nehu — Tester 
simultaneously at each station, first in one 
direction and then in the opposite direction, 
just below the surface. In addition, two in- 
terim surveys were undertaken to investigate 
the horizontal and vertical distribution of the 
eggs and larvae at one station in more detail. 
Nehu eggs and larvae were identified and 
nehu larvae were measured. The bluntly 
ovoid eggs, typical of several species of an- 
chovy, were readily recognized. Some were 
obviously damaged during tows; others, 
amounting to about 5 per cent, were ap- 
parently dead at the time of capture. 
A study of variability of the data revealed 
heterogeneity between stations, haul order 
(A and B), and nets, together with a signifi- 
cant interaction between stations and haul 
order. From the same analysis, it was found 
that the small nets were relatively more ef- 
ficient than the large net, but that this could 
be attributed in part to loss of plankton from 
the latter because of rips which developed 
during one survey, and perhaps also to poor 
technique in handling the catch in the others. 
Two interim surveys were undertaken at 
one station to determine the reason for the 
difference between A and B hauls and also to 
study the variation with depth. Both the 
heterogeneity in haul order and the inter- 
action between stations and haul order could 
be explained on the basis of non-random dis- 
tribution of the eggs. Apparently there was a 
focus of abundance of eggs, and gradients of 
decreasing abundance extending outward in 
all directions. Slight variation in the course 
followed by the vessel in making the hauls 
would produce large variation in catch be- 
cause the egg concentration would be trans- 
versed at different distances from the focus. 
The eggs were slightly more abundant 
toward the surface than at a depth. A gradient 
of decreasing abundance with depth was 
postulated. 
Both eggs and larvae were present in all 
four surveys, showing that spawning takes 
place throughout all seasons of the year. 
Whether it is generally more intensive during 
the summer than during the winter remains 
to be determined. 
Both eggs and larvae were generally most 
abundant in the southern sector of the bay, 
less abundant in the middle sector, and least 
abundant in the northern sector. 
Neither eggs nor larvae were randomly dis- 
tributed within sectors. In the southern sector 
there was evidently a focus of abundance of 
eggs in the northerly part. This peculiar dis- 
tribution is probably related to the current 
pattern, with the eggs being held in an eddy. 
There are indications that the larvae are dis- 
tributed in a similar manner to the eggs when 
first hatched, but that they gradually disperse 
as they become larger and older, and tend to 
become concentrated in the southern part of 
the bay. In the middle and northern sectors 
there were several foci of abundance of eggs, 
their presence and location probably de- 
pending on the time and place of spawning 
and the prevailing current system. 
Several modes were evident in the length 
frequency distribution of the larvae. These 
were tentatively interpreted as day groups, 
and indicated an absolute growth rate of 
about 1.5 mm. per day during the initial 
growth period. The results suggest a remark- 
ably short period between hatching and re- 
cruitment to the fishery, and a rapid overturn 
in the population, a situation which is proba- 
bly typical of anchovy populations in tropical 
waters. 
Based on the results of this preliminary 
work, a sampling program designed to 
measure total annual egg production in 
Kaneohe Bay was suggested. Details of gear, 
stations, and hauls were briefly discussed. It 
was recommended that, if possible, some 
other method of collection be used to de- 
termine the abundance of larvae. 
The investigation was confined to the 
waters of Kaneohe Bay. Although it is con- 
sidered unlikely that nehu eggs occur in 
large quantity in waters outside the bay, the 
possibility should be investigated in the 
future. 
