QUANTITATIVE ASSESSMENT OF CORAL COLONY SHAPES USING 3D SHAPE DESCRIPTORS

In scleractinian corals, the shape of colony is often used in identification, or as a morphological character in phylogenetic analyses, but rarely quantified due to lack of homology among colony shapes. In this study, methods to quantitatively assess diverse shapes of coral colonies are presented. More than one hundred coral colony specimens were digitized using a 3D scanner to obtain three-dimensional models of coral colonies. Shape descriptors such as SHELL, VOXEL and others are applied to these three-dimensional models, and the results are analyzed using multivariate statistical methods. This makes it possible to analyze three-dimensional shapes of coral colonies which was not possible with conventional morphometric techniques such as traditional measurements, landmarks, or Fourier analses. These methods of using shape descriptors seem to have the potential to contribute to morphometrical approach to wider range of taxa or biological structures.