MODELING THE INTERACTION BETWEEN BIOLOGICAL AND ENVIRONMENTAL FACTORS IN SCLERACTINIAN CORAL COLONY MORPHOGENESIS AND ITS PHYLOGENETIC IMPLICATION

Colony shape of scleractinian coral is known to be quite diverse and often one of the diagnostic features of coral genera or species. Researchers have been using colony shape as a character in their phylogenetic analyses. But the underlying mechanism of coral colony morphogenesis and how the biological and environmental factors contribute in the process is not very well understood. In this study, biological and environmental factors that can affect coral colony shape are modeled to simulate coral colony morphogenesis. Neither biological nor environmental factor alone could explain the known variety of coral colony shapes. While environmental factors such as the amount of light attenuated by water depth and clarity could cause a certain amount of change in colony shape, biological factors such as differential growth, mode of budding, and intercorallite distance appear to have more profound effects on colony shape. Genetic basis of these biological factors remains to be found. Caution is needed if colony shape is to be used as a morphological character in phylogenetic analyses.