Distribution and Abundance of Planktonic Amphipods in the Indian Ocean
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0°
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10°
•
,
/
20°
30°
S
250 400
Fig. 6. Day and night variations in the distribution of pelagic amphipods under 1 m 2 (200-0 m) in
each 10° zone of latitude for the period April 16-0ctober 15 (solid line: day, dotted line: night)
In general, the numerical abundance of amphipods is higher in areas of upwelling, off
South Africa (pronounced, especially during the southern summer), the Somali coast,
South Arabia, the west coast of India, the head of the Bay of Bengal, the Andaman coast,
and the east coast of India (maximum during the SW monsoon). In the equatorial zone
there are moderately high peaks in patches of abundance throughout the year. Lowdensity areas were noted round the year in the south central Indian Ocean, in the central
Arabian Sea and in scattered areas.
0°
10°
20°
30°
I
S
•
0
200
40°
250
Fig. 7. Day and night variations in the distribution of pelagic amphipods under 1 m 2 (200 - 0 m) in
each 10° zone of latitude for the period October 16 - April 15 (solid line: day, dotted line: night)