Hand separated radiolarian skeletons, mainly from the Panama Basin PARFLUX sediment trap (5°21.8′N, 82°01.4′W) samples, were measured for length, width, and projected area (58 species), and weight (53 species). Volume and density contrast were computed.

Fluxes of living radiolarians collected in particle traps in the North Pacific central gyre ranged from 5.4 × 104 m−2 at 50 m (of which 52% resulted from individuals of colonial radiolarians) to 103 m−2 day−1 at 2000 m. The fluxex of total radiolarians

Four time-series sediment traps at two stations and three piston cores from the Okhotsk Sea were quantitatively examined for coarse-sized radiolarian shells (>63 μm). Traps were deployed at 300 m and 1550 m at Station M4 (53°01′N, 145°30′E) and at 300

Polycystina (~400–800 living species and several thousand extinct forms) and Phaeodaria (~400–500 living species) are exclusively marine, open-ocean planktonic protists, most of which possess elaborate siliceous skeletons. The cytoplasm is divided into