Seasonal Variation of Ichthyoplankton in the Arabian Sea in Relation to Monsoons

Abstract

The seasonal variation of ichthyoplankton of the Arabian Sea based on the 694 Zooplankton samples collected during the International Indian Ocean Expedition has been discussed in the light of the hydrographical features caused by monsoons. The pattern of distribution of total fish eggs showed that the highest degree of concentration was at the northeastern and southwestern parts of Socotra Island, areas off Kutch and Gujarat, Kerala coast, south of Ceylon and Chagos archipelago. The lowest concentration was noticed in the central part of the Arabian Sea. During the southwest monsoon season there was a slight reduction in these areas of high concentration. During the northeast monsoon, however, the northeastern half of the Arabian coast was changed into an area of lowest density. The areas of high concentration along the west coast of India were retained without much change. In the case of total fish larvae the highest density was noticed in the middle of the Red Sea, also near Aden, around Socotra Island, the Arabian and southern Somali coasts, off Kutch and Bombay, along the Malabar coast, south of southern India and Ceylon, in addition to a few places along the equatorial region. The lowest density was noticed in the central part of the Arabian Sea.