Meeting Abstract
The anthozoan cnidarians (e.g., corals, sea anemones) are an ecologically important and diverse group of marine metazoans that occur from shallow to deep waters worldwide, and include some of the ocean’s most important ecosystem engineers. Our understanding of the evolutionary relationships among the ~7500 species within this class is, however, deeply flawed. Molecular phylogenetic studies have revealed widespread homoplasy in morphological characters and widespread polyphyly at the ordinal, family, and genus levels. Resolution of both deep and shallow nodes in the anthozoan phylogeny has been hindered by a lack of phylogenetically informative markers that can be sequenced reliably across taxa whose divergence may pre-date the Cambrian. While recent phylogenomic analyses have supported the reciprocal monophyly of sub-classes Octocorallia and Hexacorallia, resolution of the ordinal relationships within each clade requires more comprehensive taxon-sampling than can be achieved with transcriptomic approaches. Using all available anthozoan genomes and transcriptomes, we designed a set of 16,308 target-capture baits for enriching both ultraconserved elements (720 loci) and exons (1071 loci). Target enrichment was tested on 33 taxa representing all orders of Anthozoa. Illumina sequencing of enriched genomes recovered 1774 of 1791 targeted loci, with a mean of 638 ± 222 loci recovered per species. Maximum likelihood analyses yielded highly resolved trees with topologies matching established anthozoan relationships. We have now sequenced >200 taxa representing a majority of the known families of Anthozoa, and report here on the ability of these markers to resolve both deep and shallow relationships within the class.
