Définition : A cell shape that approximates a cylinder. (Sun, J. and Liu, D. 2003. Geometric models for calculating cell biovolume and surface area for phytoplankton, J. Plankton Res., 25, 1331–1346, doi:10.1093/plankt/fbg096, Table II)
Définition : Living in the fluid medium (water or air) but unable to maintain their position or distribution independently of the movement of the water/air mass (adapted from Lincoln et al., 1998).
Définition : Siliceous ooze is a marine sediment composed of the debris of plankton with silica shells, such as diatoms and radiolaria. This ooze is limited to areas with high biological productivity, such as the polar oceans, and upwelling zones near the equator. The least common type of sediment, it covers only 15% of the ocean floor. It accumulates at a slower rate than calcareous ooze: 0.2-1 cm / 1000 yr.
