RESUMO
Siliceous planktonic species of the phyla Retaria and Cercozoa were investigated from the surface to a 200 m depth around the eastern Indian Ocean (80.00°-96.10° E, 10.08° N-6.00° S) during a 2-month cruise (10 April-13 May 2014). These species are commonly referred to as Radiolarians and are found in all of the world's oceans; however, this is a detailed investigation of the species' diversity in the eastern Indian Ocean. Samples were collected from the eastern Indian Ocean using a plankton towing net during a vertical haul from 44 sampling stations, which resulted in 168 taxa, including 60 species that were newly recorded in the study area. The main purpose of this work was to identify members of the phyla Retaria and Cercozoa and their distribution in the eastern Indian Ocean. The species' morphology, identification, notes, and new geographical records are briefly described.