Pseudo-nitzschia pseudodelicatissima is a species of Bacillariophyceae in the family Bacillariaceae. Dead Pseudo-nitzschia pseudodelicatissima formsiliceous oozes.
Definition: 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.
Definition: A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)