344 
PACIFIC SCIENCE, Vol. V, October, 1951 
number necessary for a reasonably accurate 
estimate of the production of nehu eggs in 
Kaneohe Bay. 
The above program would provide data on 
variation in the abundance of eggs and, there- 
fore, on variation in the abundance of the 
sexually mature portion of the fishable stock. 
Coupled with information on mortality and 
catch, it could lead to predictions of abun- 
dance of the mature population at various 
levels of fishing effort. 
Estimation of larva abundance from plank- 
ton hauls is more difficult because of the 
widespread but non-random distribution of 
the larvae and their increased ability to escape 
the net as they become larger. Special stations 
for the estimation of larva abundance might 
be established, e.g.. Station 7 in the southern 
sector, but this would greatly increase the 
number of samples to be collected and sorted. 
It might be possible to measure the abun- 
dance of larvae more accurately and with less 
effort by another method of collection- 
quantitative night-light traps. This possibil- 
ity is now under investigation. 
The reasons for the peculiar distribution of 
eggs and larvae in Kaneohe Bay are unknown, 
although presumably the distribution is re- 
lated to the prevailing current pattern. A 
hydrographic study of the current system in 
all sectors of the bay at various times of year 
and under various weather and tide condi- 
tions is highly desirable. 
The investigation was confined to the 
waters within Kaneohe Bay. There is the 
possibility that nehu eggs may also occur in 
coastal and offshore waters outside the bay. 
The presence of anchovy eggs in offshore 
waters has been reported for other species, 
e.g., the Australian anchovy, EngrauUs aus- 
tralis, investigated by Blackburn (1941), the 
California or Northern anchovy, EngrauUs 
mordax, investigated by Marr and Ahlstrom 
(1948), and several species of EngrauUs oc- 
curring along the coast of Java and Sumatra, 
investigated by Delsman (1929). Further- 
more, the eggs of several species of Stole- 
phorus were also found offshore by Delsman 
(1931) in the last-named tropical locality. On 
the other hand, our local anchovy, the nehu, 
does not characteristically occur in the open 
ocean. As pointed out by Tester and Hiatt 
(in press), it appears to be confined to the 
bays and inlets where the water is somewhat 
more turbid and less saline than that of the 
open sea. As far as can be determined, nehu 
eggs have not yet been recovered from off- 
shore waters adjacent to Hawaii by other 
agencies in the Territory who have made !> 
plankton hauls for pelagic fish eggs. Al- j 
though it seems likely that nehu eggs do not |1 
occur extensively in offshore waters, the !| 
possibility that they are carried to or spawned ii 
in the open sea should be investigated. ii 
The early life history of the nehu appears ;l 
to be similar to that of the tropical anchovies 1 
studied by Delsman (1929 and 1931). In both, j| 
spawning takes place throughout the year, ; 
spawning occurs at night, there is a rapid 
embryonic development with an incubation 
period of 24 hours or less, and there is rapid , 
growth during the larval stages. Two general 
features — continuous spawning and rapid ; 
development — present new problems in the ^ 
field of fishery management. 
SUMMARY j 
An investigation of the distribution of j 
anchovy or "nehu” eggs and larvae in Kane- 
ohe Bay, Oahu, Territory of Hawaii, was con- | 
ducted during 1948 and 1949. It was explora- | 
tory in nature, and was designed partly to | 
determine an efficient sampling program and : 
partly to obtain information on the horizon- 
tal, vertical, and seasonal distribution of the | 
eggs and larvae. 
In each of four surveys (September, De- ■ 
cember, March, and June) 23 stations were 
sampled. Of these, nine were in the southern 
sector, eight in the middle sector, and six in i 
the northern sector of the bay. 
Three nets with respective mouth diameters 
of 100, 22, and 12.3 cm. were used. The large , 
net and one of the two small nets were towed 
