Zooxanthellae

Zooxanthellae are photosynthetic dinoflagellates of family Symbiodiniaceae that live within the tissues of sea anemones and reef-building corals. They photosynthesize using sunlight, CO₂, and nutrients, providing corals with up to 90% of energy needs in clear, shallow tropical waters. In return, they receive nutrients from captured prey, CO₂ from respiration, and a protected environment.

This partnership enables corals to thrive in nutrient-poor tropical waters and construct massive reef structures - neither partner could create reefs alone. The coral reef ecosystem demonstrates complex mutualistic synergies.