Central Pacific Salpidae — -YOUNT 
119 
- 
- 
b 
- 
- 
= = Salpa fusiformis 
- 
„ 
= Ritteriella amboinensis 
- 
_ 
:* =Cyclosalpa pinnata 
. 
_ ' • 
r ■- 
- 
h 1 
£ 
- 
» Rt = 
^ lik L 
1 
rtf-- m jr-. rth- rr Bi 
1 J 1 — 
i i i 
J 1 
^ 1 1 J _J _! 1 
i 
SOUTH O* NORTH 
Fig. 4. Cruise 5, 172° W. longitude, a, Relationship of total salp volume, total salp numbers, and numbers of 
Thalia democratica to major currents, upwelling, and island masses. Limits of currents, upwelling, and islands are 
approximate, b, Relationship of the other common species, Salpa fusiformis , Ritteriella amhoinensis, and Cyclosalpa 
pinnata to major factors listed in a. 
relationship to the ecologic factors examined. 
The section of cruise 8, 172° W. (Fig. 6), 
shows that relatively large volumes were taken 
in the region of upwelling and near the cur- 
rent margins of the Counter and North Equa- 
torial Currents. Relatively great numbers were 
taken also in these regions, with a predomi- 
nance of the greater numbers near the region 
of upwelling. 
In summary, it can be stated that most of 
the greater volumes and numbers of salps 
taken on these longitudes were taken either 
within or near the cool enriched upwelled 
waters, in regions possibly influenced by cur- 
rent shear, or in regions in which there was a 
possible island influence on their abundance. 
The effect of temperature on salp abundance 
is undoubtedly only indirect within the ranges 
found on these cruises, inasmuch as cool non- 
upwelled waters contained, in general, rela- 
tively few salps except near islands. This 
predominance of greater volumes in regions 
of upwelling occurred on cruise 5, 158° and 
172° W., and cruise 8, 172° W. The abundance 
