BioProject

Molecular phylogenetics is fundamentally altering our understanding of the taxonomy, systematics and biogeography of corals. More...

Molecular phylogenetics is fundamentally altering our understanding of the taxonomy, systematics and biogeography of corals. Single-locus markers have proved effective for resolving systematic relationships at higher taxonomic levels, but lack the power to delineate species-level relationships in the most speciose genera. Recently-developed phylogenomic techniques have identified the broad structure of the diverse and ecologically-important genus Acropora, and provide a path for resolving species-level relationships in this notoriously problematic group. Here, we use a targeted capture dataset (2032 loci) to investigate systematic relationships within a clade of Acropora that contains the putatively widespread 'lab rat' species A. tenuis and its relatives. We examine 57 specimens collected from across the Indo-Pacific, as well as harvesting loci from two published A. tenuis genomes from different geographic regions. Maximum likelihood phylogenies of targeted loci and genetic clustering of SNPs called from those loci indicate the presence of at least eleven distinct lineages, only four of which correspond to currently accepted species. Based on molecular, morphological and geographic evidence, we describe two new species (A. rongoi n. sp. and A. tenuissima n. sp.), and provide evidence that four additional nominal species (A. macrostoma [Brook 1891], A. kenti [Brook 1892], A. bifaria [Brook 1892] and A. africana [Brook 1893] are not junior synonyms of A. tenuis (Dana 1846). Systematic relationships within the clade revealed by our molecular phylogeny are incongruent with species boundaries and assumed evolutionary relationships based on traditional morphological taxonomy, and demonstrates that many characters used to define species and infer evolutionary history are not phylogenetically informative. Furthermore, we show that species within this clade are not widespread across the Indo-Pacific, but restricted to particular regions within the Indo-Pacific, a finding with profound implications for conservation and management of reef corals. Less...