PIGMENT COMPOSITION IN DIFFERENT-COLORED SCLERACTINIAN CORALS BEFORE AND DURING THE BLEACHING PROCESS

Pigment composition in different-colored scleractinian corals before a nd during the bleaching process. Zoological Studies 34(1): 10-17. Scle ractinian corals have many different color types in water. All the col ors become bleached when the coral is under stress. The pigment change s behind these phenomena were investigated in the study. Analysis of p igment composition in four color types of seven stony coral species sh owed chi. a, chi. c(2), peridinin, diadinoxanthin and dinoxanthin comp rised 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 pigment in each zo oxanthellae decreased with time. The rate of decline of porphyrins coi ncided with the level of stress that was created by lowering the salin ity of the incubation sea water. The rate of decline of carotenoids wa s less sensitive. This suggests that the rate of change of porphyrins could reflect the bleaching status of stony coral.