Eggs and Larvae of the Nehu — Tester 
! 
i eggs in the blastodermal cap stage, and more 
advanced eggs closer to the hatching stage, 
i: were not encountered. It has since been found 
(Yamashita, MS.) that spawning takes place 
at night, mostly from about 10 P.M. to mid- 
! night, and that development from fertiliza- 
i tion to hatching occurs in about 24 hours. 
This explains the rather uniform stage of 
development of the eggs, for in all tows they 
were taken during the same 5 -hour period of 
the day — from about 9 a.m. to 2 p.m. Similar 
observations have been made by Delsman 
( 1929 ) who pointed out that night spawning 
and rapid embryonic development are typical 
of tropical species of EngrauUs and Stole- 
phorus occurring in Javanese waters. 
Nehu larvae have been hatched in small 
shallow dishes of sea water from eggs taken 
327 
in plankton hauls (Yamashita, MS.). The 
newly hatched larvae, about 2 mm. in length, 
have a large, crescent-shaped yolk sac attached 
to the ventral surface of the body from head 
to vent. This is gradually absorbed until, at 
36 hours after hatching, only a small round 
ball of yolk remains at the "throat.” During 
these early stages the larvae may be recog- 
nized fairly readily by their size, the slender 
elongated body form, the shape and position 
of the yolk sac when present, the reticulated 
appearance of the myotomes, the origin of 
the dorsal fin fold at the posterior end of the 
head, and the position of the anus, which is 
from two-thirds to three-quarters of the dis- 
tance along the body. At the more advanced 
stages, the chief diagnostic characters are the 
slender body form, the reticulated appearance 
TABLE 3 
Number of Nehu Eggs per 10-Minute Surface Haul with the 100 cm. Net according to 
Survey, Station, and Direction (A and B), and Summary 
STATION 
SUR\ 
^EY 1 
SURVEY 2 
SURVEY 3 
SURV 
^EY 4 
MEAN PER CENT 
OF SURVEY 
TOTAL 
A 
B 
A 
B 
A 
B 
A 
B 
1 
— 
— 
— 
— 
— 
— 
5 
11 
0.16 
2 
- 
- 
- 
- 
- 
15 
- 
, 3 
0.07 
3 
233 
314 
21 
107 
89 
347 
6 
29 
5.12 
4 
1,930 
956 
383 
490 
4,180 
4,781 
127 
296 
48.63 
5 
769 
116 
419 
332 
38 
2 
262 
259 
18.41 
6 
30 
10 
3 
3 
1 
- 
3 
2 
0.28 
7 
2 
- 
3 
2 
- 
- 
8 
2 
0.17 
8 
- 
1 
- 
- 
- 
- 
53 
27 
0.82 
9 
6 
3 
3 
2 
23 
149 
123 
17 
1.97 
10 
— 
2 
7 
2 
8 
4 
— 
— 
0.15 
11 
- 
1 
7 
5 
1 
- 
- 
- 
0.16 
12 
3 
5 
3 
0* 
5 
3 
- 
- 
0.09 
13 
56 
172 
10 
4 
55 
113 
4 
2 
1.51 
14 
223 
117 
18 
5 
14 
8 
326 
150 
6.50 
15 
111 
113 
18 
21 
8 
22 
125 
121 
3.94 
16 
8 
8 
27 
1 
73 
34 
166 
122 
3.65 
17 
. 495 
141 
21 
23 
31 
15 
39 
30 
3.74 
18 
262 
143 
— 
— 
2 
— 
— 
_ 
1.50 
19 
- 
- 
- 
- 
- 
- 
15 
11 
0.27 
20 
310 
205 
- 
- 
- 
1 
45 
33 
2.71 
21 
12 
- 
- 
- 
- 
- 
8 
1 
0.14 
22 
- 
- 
- 
- 
- 
— 
1 
- 
0.01 
23 
— 
— 
— 
- 
- 
- 
- 
— 
0.00 
Totals .... 
4,450 
2,307 
943 
997 
4,528 
5,494 
1,316 
1,116 
100.00 
* Part of haul lost. 
