See Corallina vancouveriensis in animated form (Quicktime movie). The video depicts a single thallus living happily (photosynthesizing and becoming strong) between two sea anemones of the species Anthopleura elegantissima until they decide to leave. After their departure the alga suffers increased desiccation and in response becomes smaller and more compact. This change in morphology and interaction with this sea anemone group is discussed more fully in the Ecology section.