Intertidal coralline algae face challenges like light, drying out, and temperature changes daily. Different species handle these stresses in various ways, affecting where they live on the shore. In a study, two types of coralline algae were tested in simulated tidal conditions. One type, Corallina, did better in high tide with more light, while the other type, Calliarthron, struggled. When submerged in warm tidepools, Corallina still outperformed Calliarthron. Both algae stopped photosynthesizing when exposed to air during low tide. Corallina was better at holding onto water and recovering from stress when the tide came back. These findings show how different physiological responses help algae survive in their habitats.