Planktonic Ostracods of the Northern Indian Ocean

Abstract

Thirty-two species of ostracods were identified from 712 samples collected from northern Indian Ocean. Two of them belong to Cypridinidae and the rest to Halocyprididae. Most of the species are common to those of the Atlantic and Pacific Oceans. Paraconchoecia decipiens and Orthoconchoecia striola alone could be considered as typical Indo-Pacific species. In general, Arabian Sea sustained a rich ostracod fauna. Euconchoecia aculeata was the dominant species in the northern Indian Ocean. In the Arabian Sea Cypridina dentata was the most abundant species confined largely in the neritic areas and off the west coast of India. Most of the widely distributed species could tolerate a salinity range of 32-37 ppt. Statistical analysis of the data using students 't' test indicated that 5 species showed seasonal variations and four species gave significant 't' values for day and night variations