Both hard and soft corals have a symbiotic relationship with zooxanthellae algae, which live in coral and give it its color. 硬和软珊瑚两者有共生关系和虫黄藻藻类，那些生活在珊瑚和给它的颜色。
The relationship between skeleton calcification and photosynthesis of zooxanthellae is a controversial question, and the mechanism of calcification is still being explored. 骨骼钙化作用和虫黄藻光合作用的相互关系还存有争议，珊瑚骨骼钙化机理仍在探索中。
