390 
TABLE 11 
Day and Night Depth Distributions for 
Vibilia viatrix 
DEPTH IN 
METERS 
TOTAL NO. 
SAMPLES 
NO. 
POSITIVE 
SAMPLES 
PER CENT 
POSITIVE 
Night 
0-50 
4 
4 
100 
50-100 
2 
1 
50 
100-200 
7 
4 
57 
200-300 
4 
3 
75 
300-400 
6 
4 
66 
400-500 
2 
2 
100 
500-600 
7 
1 
14 
600-700 
2 
2 
100 
700-800 
1 
1 
100 
800-900 
1 
0 
0 
900-1100 
3 
0 
0 
Day 
0-50 
2 
2 
100 
50-100 
2 
1 
50 
100-200 
2 
1 
50 
200-300 
4 
1 
25 
300-400 
4 
4 
100 
400-500 
5 
4 
80 
500-600 
5 
4 
80 
600-700 
4 
2 
50 
700-800 
3 
3 
100 
800-900 
4 
3 
75 
900-1100 
8 
7 
87 
1932:283-284; Thorsteinson, 1945:236; Hur- 
ley, 1956:16. 
Phronima sedentaria was collected in 53 
trawls at depths of from 80 to 1100 m. A total 
of 575 individuals was sorted from quantitative 
aliquots. 
During the daytime this species was found 
at depths ranging from about 275 to 1100 m, 
with the greatest concentrations noted above 
400 m. There was a distinct rise of the popu- 
lation toward the surface at night (Table 12). 
The deep, positive samples at night may be 
the result of either a descent during the dark 
hours or the presence of a nonmigrating por- 
tion of the population residing below the depth 
of perceivable light. There is also the proba- 
bility of some contamination from shallower 
depths. 
It has been suggested in much of the earlier 
literature that only the young of this species 
were ever captured near the surface and that 
PACIFIC SCIENCE, Vol. XXI, July 1967 
TABLE 12 
Day and Night Depth Distributions for 
Phronima sedentaria 
DEPTH IN 
METERS 
TOTAL NO. 
SAMPLES 
NO. 
POSITIVE 
SAMPLES 
PER CENT 
POSITIVE 
Night 
0-50 
4 
0 
0 
50-100 
2 
2 
100 
100-200 
7 
7 
100 
200-300 
4 
2 
50 
300-400 
6 
4 
66 
400-500 
2 
0 
0 
500-600 
7 
3 
47 
600-700 
2 
2 
100 
700-800 
1 
1 
100 
800-900 
1 
0 
0 
900-1100 
3 
2 
75 
Day 
0-50 
2 
0 
0 
50-100 
2 
0 
0 
100-200 
2 
0 
0 
200-300 
4 
4 
100 
300-400 
4 
4 
100 
400-500 
5 
4 
80 
500-600 
5 
4 
80 
600-700 
4 
2 
50 
700-800 
3 
2 
75 
800-900 
4 
2 
50 
900-1100 
8 
6 
75 
the adults were typically taken in deep trawls. 
Mean size records obtained during this present 
study showed no difference in age groups for 
individuals captured above and below a depth 
of 100 m. 
Family paraphronimidae 
Paraphronima gracilus Claus 
Paraphronima gracilus Stephensen, 1924: 
75-77; Chevreux and Fage, 1925:391, fig. 394; 
Pirlot, 1929:104-105; Barnard, K. H., 1932: 
267; Hurley, 1956:12-13. 
Paraphronima gracilus was taken in 49 trawls 
ranging in depth from 80 to 1100 m. A total 
of 472 individuals was sorted from pint ali 
quots. 
The greatest concentrations of individuals 
during the daylight hours were found at depths 
of from 275 to 400 m. This species occurred 
