Radiolaria are the primary contributors to biogenic opal in the tropical ocean, and their isotope compositions are potentially useful tool for reconstructing the silicon cycle in mid-depth waters. To date little attention has been paid to their isotopic

DNA metabarcoding on a single organism is a promising approach to clarify the biological interactions (e.g., predator–prey relationships and symbiosis, including parasitism) of difficult-to-culture protists. To evaluate the effectiveness of this method,

Marine picocyanobacteria Prochlorococcus and Synechococcus, the most abundant photosynthetic cells in the oceans, are generally thought to have a primarily single-celled and free-living lifestyle. However, while studying the ability of picocyanobacteria