332 
PACIFIC SCIENCE, VoL XIII, October, 1959 
HOURS 
1201 14 
22 2401 0 2 
HOURS. 
Fig. 9. The diurnal variation as shown by 2-hour averages of the data in Figure 8. 
10 1101 
from 18 stations; 3,500 Parathemisto juveniles 
from 32 stations. The numbers of juveniles 
captured decrease rapidly between Eebruary 
and March (Fig. 7) but, even so, they were 
present in fairly high numbers throughout 
the summer. They ranged in size between 
specimens just released from the brood pouch 
to about 6.5 mm. long (at which length they 
usually can be assigned to sex and species), 
and because of their numbers are probably 
important in food cycles. 
Barnard (1930) noted an increase in the 
sizes of the adults of Amphipoda at higher 
latitudes. In the present material, specimens 
of Cyllopus magellanicus, captured in the 
warmed waters (12-13°C.) of subantarctic ori- 
gin off the New Zealand coast, averaged 7 to 
8 mm. long and only occasionally exceeded 
9 mm.; those from Station 826 (Fig. 6), in 
colder water (8.6°C.), averaged 9 to 10 mm. 
and were often 11 mm. and longer. If num- 
bers of a species were maintained in the 
colder waters, such an increase in size would 
be reflected in an increased bulk of material 
available as food. Thus the size-increase in 
southern waters may well be related to pro- 
duction, the more so if it is a widespread 
phenomenon among those dominant species 
of the zooplankton. 
Except for juvenile stages, the numbers of 
the species of amphipods captured do not 
reach those of some euphausiids or copepods 
in the area, but their large size and frequent 
occurrence in both oceanic and coastal waters 
(together with the fact that oceanic species 
may extend into coastal waters), suggest that 
species are important in productivity through- 
out the area. This is in part borne out by the 
quantities of these and other species of am- 
phipod which are often present in the stom- 
ach contents of birds (e.g., Dawbin, 1954), 
and by personal observations of Puffinus 
griseus (flocks of which reach many thousands 
of birds) and of fish stomachs. 
DISCUSSION AND SUMMARY 
Of the 14 species of hyperiid Amphipoda 
collected by the ''Lachlan” between Welling- 
ton and Auckland-Campbell islands, five are 
sufficiently common to be of value in studies 
of distribution. The occurrences of these and 
the remaining nine species are of interest 
when considered in relation to the water 
properties from which they were taken. In 
general, a strong affinity to the subantarctic, 
and to a lesser extent the antarctic faunas, is 
indicated in the frequent occurrences of spe- 
cies typical of southern waters, viz., Parathe- 
