PHYLOGENETIC ANALYSIS OF THE CORAL FAMILY MUSSIDAE (SCLERACTINIA) USING MICROMORPHOLOGICAL AND MICROSTRUCTURAL CHARACTERS

Many aspects of reef coral morphology are highly plastic, and reconstructing scleractinian phylogenies using morphology has long been problematic. Characters based on coral skeletal micromorphology and microstructure may be less homoplastic than traditional larger scale morphological characters. Micromorphological characters involve details of the septal teeth and associated features, whereas microstructural characters involve the internal structure of septa, corallite walls, and dissepiments. These micro-features can be visualized in thin section or using scanning electron microscopy.

Although coral micro-features have been of interest for decades, particularly among researchers studying biomineralization and reconstructing paleoclimate, few have attempted using micro-features in phylogenetic analyses.

This project was an attempt to explore the utility and relevance of micro-features in scleractinian phylogenetics. We conducted a maximum parsimony phylogenetic analysis using micro-features as characters for twelve species within the scleractinian family Mussidae (Ortmann, 1890). The results suggest that, in this family, a phylogeny based on a combination of macro and micro characters is more consistent with molecular phylogenies than one based on traditional macromorphological characters alone, attesting to the phylogenetic significance of coral micro-features.