The evolutionary history of the “Galaxy coral” (Galaxea fascicularis), a common reef-builder in the Indo-Pacific from the Red Sea to Samoa. Major genetic differentiation is probably linked to the restricted connectivity between the Indian and Pacific Ocean through geologic times.
Example photographs of Galaxea specimens of different taxonomic species. A: G. fascicularis, lineage “S”, PW575 from Seragaki; B: G. fascicularis, lineage “L”, PW100 from Iheya, C: G. fascicularis, lineage “L+”, PW42 from Miyako; D: G. paucisepta, PW571 from Seragaki; E: G. cryptoramosa, PW249 from Seragaki; F: G. horrescens, AF-3 from Guam; G: G paucisepta (overgrowing G. astreata), PW573 from Seragaki; H: G. astreata, PW572 from Seragaki; I: G. astreata, PW448 from Motobu.RAD-seq phylogeny and distribution map of Galaxea. Galaxea is divided into three distinct clades (Chagossian, Indo-Pacific, and Pacific clade) without correlation to the taxonomic species. Mitochondrial haplotypes are conserved. Both mitochondrial and morphological data do not reflect the genomic diversity.
Patricia Himeka Wepfer 