Yasuhide Nakamura
Skeletal structure, phylogeny, taxonomy and symbiosis of Phaeodaria and Radiolaria
Phaeodaria and Radiolaria are groups of marine protists bearing siliceous skeletons. Molecular studies revealed that Phaeodaria are phylogenetically different from Radiolaria, however, the morphological diversity and intra-group phylogeny of Phaeodaria are still wrapped in mystery. Furthermore, the species diversity of Radiolaria has not sufficiently been clarified, and numerous new taxa have recently been reported. Given this situation, the difference in skeletal structure between Phaeodaria (porous) and Radiolaria (solid) will be presented showing data of Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and Micro-Xray Computed Tomography (MXCT). The latest knowledge on the phylogeny, taxonomy and symbiosis of Phaeodaria and Radiolaria will also be explained in this presentation.

Dewi Langlet
Foraminiferal contribution to benthic ecosystem functioning
In this talk I will present the results of some case studies discussing how foraminifera contribute to the benthic ecosystem functioning. Ecological observations in low-oxygen settings showed notable resistance to hypoxic conditions and high contribution to benthic nitrate reduction via denitrification. We also studied the diverse symbioses of foraminifera showing that harbour photosymbionts contributing to O2 production in coastal environment and bacterial symbionts that might be involved in various anaerobic pathways. Finally, work on foraminiferal bioturbation suggest that they are involved in sediment reworking and bio-irrigation making them single-celled ecosystem engineers.