Egg and Larva Production of Nehu — Tester 
tailed in some aspects and expanded in others, 
was started in 1950 and the data obtained 
form the basis for the present paper. 
Acknowledgments 
The investigation could not have been un- 
dertaken with efficiency without the special- 
ized knowledge and ever- willing cooperation 
of Mr. Zukeran, skipper of the University’s 
research vessel ”Salpa.” He assumed the re- 
sponsibility of locating the sampling stations 
and of supervising the sampling procedure. 
Assistance by several graduate students of the 
University of Hawaii in field work and par- 
ticularly in sorting plankton hauls in the lab- 
oratory, in counting nehu eggs and larvae, 
and in measuring fish is also gratefully ac- 
knowledged. These included Miss Tetsuko 
Fujita, Mr. Michio Takata, Mr. Royden Ikeda, 
and Mr. Austin Pritchard. 
METHODS AND MATERIAL 
Eggs and larvae were collected with spec- 
ially constructed plankton nets having a 
mouth opening of 50 cm. and an overall 
length of 2 meters. They were modeled after 
the Hensen egg net, i.e., the diameter ex- 
panded to 75 cm. over a distance of 30 cm. 
back of the mouth, and then contracted in 
a cone with a 9 cm. diameter at the cod end. 
The forward expanding part was made of 
light canvas; the after conical part was made 
of No. 40 mesh, xxx grit gauze (aperture 
0.47 mm.). An Atlas current meter was sus- 
pended in the center of the mouth by three 
wire supports equipped with turnbuckles. A 
•cod end, also of No. 40 mesh grit gauze, 30 
cm. in length and 9 cm. in diameter, was 
fastened to the end of the net by a detachable 
net band. 
Sampling was confined to the vicinity of 
■Station 4, located between Coconut Island 
and Mokapu Peninsula (Fig. 2) where as al- 
ready indicated, previous work had shown a 
fairly consistent peak of abundance of nehu 
eggs (Tester, 1951: 336). Three substations 
Fig. 2. Map showing the location of Substations 
A, B, and C at Station 4. 
(A, B, and C) were chosen at the apices of an 
equilateral triangle such that they were ap- 
proximately 800 meters apart. Their positions 
were fixed by reference points on shore so 
that they could be located with reasonable 
precision on each trip. 
Hauls were made twice a week, usually on 
Tuesday and Friday or on Monday and Thurs- 
day, starting August 31, 1950 and ending 
September 2, 1952. The sequence was inter- 
rupted only in two weeks when the "Salpa” 
was out of commission, and only one haul 
per week was made. On two occasions when 
the "Salpa” was in dry dock, the hauls were 
made from a 24-foot plane personnel boat, 
but the methods and procedures were essen- 
tially similar to those used with the other 
vessel. 
On each trip to Station 4, one 5 -minute 
haul was made at each of the three substa- 
tions, following a circular course with a diam- 
eter of about 300 meters. The circular rather 
than straight line course was chosen in order 
to keep the sampling within the presumed 
area of egg concentration and to avoid a bias 
