Trans-Pacific RAD-Seq population genomics confirms introgressive hybridization in Eastern Pacific Pocillopora corals.

Discrepancies between morphology-based taxonomy and phylogenetic systematics are common in Scleractinian corals. In Pocillopora corals, nine recently identified genetic lineages disagree fundamentally with the 17 recognized Pocillopora species, including 5 major Indo-Pacific reef-builders. Pocillopora corals hybridize in the Tropical Eastern Pacific, so it is possible that some of the disagreement between the genetics and taxonomy may be due to introgressive hybridization. Here we used 6769 genome-wide SNPs from Restriction-site Associated DNA sequencing (RAD-Seq) to conduct phylogenomic comparisons among three common, Indo-Pacific Pocillopora species - P.'damicornis, P. eydouxi and P. elegans - within and between populations in the Tropical Eastern Pacific (TEP) and the Central Pacific. Genome-wide RAD-Seq comparisons of Central and TEP Pocillopora confirm that the morphospecies P.'damicornis, P. eydouxi and P. elegans are not monophyletic, but instead fall into three distinct genetic ...