Synedra excluded Asterionella due to:
“Efficient resource use” for synedra excluded asterionella due to. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. Habitat describes where an organism occurs; niche additionally describes how it obtains resources and affects or responds to other organisms. Distribution therefore provides evidence about a niche but is not identical to it. The remaining alternatives—“Faster reproduction”, “High predation”, “Larger size”—refer to different states, processes, or scales and therefore do not express the
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 13