All Diatoms and Other Microalgae

Single celled and small colonial photosynthetic protists too small to see individually without magnification, the diatoms with their silica shells foremost among them, alongside other microalgal lineages such as coccolithophores, cryptomonads, haptophytes, glaucophytes, euglenoids, yellow-green algae and unicellular green algae. Covers the phytoplankton that forms the base of most aquatic food webs, identified by their own sourced description rather than by name. Excludes dinoflagellates, grouped separately despite also being unicellular photosynthetic plankton, and excludes the multicellular seaweeds and macroalgae, which belong in that subcategory instead.