The vertical distribution of Radiolaria in the waters surrounding Japan

We recognized five radiolarian assemblages: the Upper Surface Assemblage (0-40 m), the Lower Surface Assemblage (40-80 m), the Surface Assemblage (0-80 m), the Subsurface Assemblage (80-200 m), and the Lower Surface-Subsurface Assemblage (40-200 m) groups. Pseudodictyophimus gracilipes and Tetrapyle octacantha (juvenile) show “tropical submergence”, i.e. they live at the surface in high latitudes and at greater depth in low latitudes. Four taxa live at specific temperature and salinity: Acrosphaera spinosa, Larcopyle butschlii, Challengeron diodon, and Stichocorys seriata. Four taxa are associated with characteristic temperatures: Neosemantis distephanus, Arachnocorys umbellifura, Antarctissa sp. 1, and Saccospyris conithorax.