78 
PACIFIC SCIENCE, Vol. XVIII, January 1964 
smallest number of species per unit volume of 
water filtered was found in the arctic-subarctic 
and antarctic-subantarctic regions and in some 
localities of the transition and neritic areas (per- 
sonal data). The greatest specific diversity with 
a small number of specimens was found in the 
subtropical, tropical, and equatorial waters, and 
in regions of mixing of waters from the above 
extreme geographical regions. 
To emphasize the importance of the ocean’s 
circulation with respect to zonation in depth of 
chaetognath species, diagrams from the different 
geographical localities and zones of dynamic 
disturbances have been prepared (Fig. 11). 
These diagrams show in general the quantita- 
tive specific distribution in depth of the Chae- 
tognatha in the different water masses of the 
Pacific. The results obtained do not preclude 
the possibility that in the future, with more de- 
tailed studies, some slight variations may be ob- 
served. The California region includes the species 
recorded there from latitude 42 ° N to the south- 
ernmost tip of Baja California. This region 
appears to have the greatest number of species 
of chaetognaths in the upper 200 m, and the 
study of those species indicates the various 
origins of the inflows into the region. In Figure 
TABLE 2 
Ontogenic Vertical Distribution of S. scrippsae 
LATITUDE N 
DEPTH 
(meters) 
MAXIMUM SIZE 
(millimeters) 
46° 
140 
<30 
200 
40 
300 
50 
below 300 
60 
39° 
170 
<30 
340 
40 
510 
50 
680 
60 
Fig. 12. Ontogenic vertical and latitudinal distribution of S. gazellae. 
