A modern scleractinian coral with a two-component calcite–aragonite skeleton
Jarosław Stolarski, Ismael Coronado, Jack G. Murphy, Marcelo Visentini Kitahara, Katarzyna Janiszewska, Maciej Mazur, Anne M. Gothmann, Anne‐Sophie Bouvier, Johanna Marin‐Carbonne, Michelle L. Taylor, Andrea M. Quattrini, Catherine S. McFadden, John A. Higgins, Laura F. Robinson, Anders Meibom
Abstract
Significance Until now, all of the ca. 1,800 known modern scleractinian coral species were thought to produce skeletons exclusively of aragonite. Asymbiotic Paraconotrochus antarcticus living in the Southern Ocean is the first example of an extant scleractinian that forms a two-component carbonate skeleton, with an inner structure made of high-Mg calcite and an outer structure composed of aragonite. This discovery adds support to the notion that the coral skeletal formation process is strongly biologically controlled. Mitophylogenomic analysis shows that P . antarcticus represents an ancient scleractinian clade, suggesting that skeletal mineralogy/polymorph of a taxon, once established, is a trait conserved throughout the evolution of that clade.