Scleractinian corals have many different color types in water. All the colors become bleached when the coral is under stress. The pigment changes behind these phenomena were investigated in the study . Analysis of pigment composition in four colo r types of seven stony coral species showed chl. a, chl. C2, peridinin , diadinoxanthin and dinoxanthin comprised more than 95% of the total amount of pigments. There was little compositional difference between these pigments in corals of different color. During bleaching caused by salinity change, both the number of zooxanthella in each polyp and the amount of total pigmen t in each zooxanthellae decreased with time . The rate of declin e of porphyrins coincided with the level of stress that was created by lowerin g the salinity of the incubation sea water. The rate of decline of carotenoids was less sensitive. This suggests that the rate of change of porphyrins could reflect the bleach ing status of stony coral.
Scleractinian coral, Pigments, Bleach ing, Salinity
