PRJNA665126
Species delimitation in tabular Acropora from Sesoko Island (Okinawa, Japan)
A working coral taxonomy is crucial for meaningful physiological, ecological or population genetic studies of these keystone organisms, as well as for effective management and conservation of reef ecosystems. In coral genera such as the Acropora, high morphological plasticity and a dearth of informative molecular markers have made species delimitation particularly difficult. Here, we used three independent approaches, morphology, DNA and breeding trials to identify species boundaries in the tabular Acropora of Sesoko Island, Okinawa, Japan. All three approaches suggested there were three distinct species; Acropora aff. hyacinthus, A. cf. cytherea and the previously synonymised A. cf. bifurcata. Field identifications, based largely on color, radial corallite shape and distribution, distinguished three morpho-species that were supported by fertilization rates in experimental crosses between representative colonies of each group. These three groups were also differentiated by target capture sequencing of conserved elements (both ultraconserved elements and exon loci) and traditional sequencing of markers defined from these loci; the first time a molecular approach has successfully resolved closely related Acropora species. Our work suggests that an integrative approach, comparing evidence arising from numerous independent sources, is the key to the development of an accurate taxonomy in the Scleractinia.