[Solved] Which incision is traditionally used for open appendectomy? A) McBurney B) median vertical C) paramedian D) Pfannenstiel Zooxanthellae: Photosynthetic algae found in close symbiotic relationships with marine invertebrates such as corals and sea anemones. Microscopic Algae: Tiny, often unicellular algae, not visible to the naked eye, that live in water and can perform photosynthesis. Phytoplankton: Microscopic floating algae and cyanobacteria that are the base of most aquatic food webs. Compare with zooplankton. See plankton and nanoplankton. Classification: The systematic organization of living things into categories based on shared attributes or evolutionary ancestry.