364
E. BRINTON and K. GOPALAKRISHNAN:
common as far south as 5 ° S off Africa. Neither species showed seasonality in the
Andaman Sea region.
Euphausia diomediae (Fig. 3 a, b) is a third characteristic species of the northern part
of the ocean. It is more typically oceanic, ranging along the full extent of the tropical belts
of the Pacific and Indian Oceans. It nevertheless achieves abundance in the fertile Somalia
and Arabian regions, and occasionally in the Bay of Bengal. Occurrences of this species
. ' i l
l
0
~
.
0
k
?
..
I
' .
? ' . 1
I :
. •
- - . 1.29" _ - - - ,.._ . - !!&". ~30"
May - Seplember
Fig. 3 a. Euphausia diomediae, E. mutica, E. recurva, May-September
taper off to the south of 10° S, but there were 6 records in the Natal Basin during MaySeptember.
Toward the south, E. diomediae tends to be replaced by Euphausia brevis at 0 ° -10 ° S
(Fig. 4 a, b). Euphausia mutica appears in the zone of 10
0 -
20
0
S (Fig. 3 a, b), and
Euphausia recurva in the zone of 25° -40° S. Subantarctic Euphausia species (e.g., E.
spinifera, E. lucens) were not well represented in the HOE collections, occurring to the
south of 35° -40° S.