More is needed—Thousands of loci are required to elucidate the relationships of the ‘flowers of the sea’ (Sabellida, Annelida)

• Published in: Molecular phylogenetics and evolution Vol. 151; p. 106892
• Main Authors: Tilic, Ekin, Sayyari, Erfan, Stiller, Josefin, Mirarab, Siavash, Rouse, Greg W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2020
• Subjects: Animals; Annelida - classification; Annelida - genetics; Data Analysis; DNA; Fabriciidae; flowers; genes; Genetic Loci; Likelihood Functions; loci; Phylogenomics; Phylogeny; Sabellidae; Serpulidae; Species Specificity; topology; transcriptome; Transcriptome - genetics; Transcriptomics; Sabellidae; Transcriptomics; Phylogenomics; Fabriciidae; Serpulidae
• ISSN: 1055-7903; 1095-9513; 1095-9513
• DOI: 10.1016/j.ympev.2020.106892

[Display omitted] •Fabriciidae is the sister taxon to a Sabellidae + Serpulidae clade.•Sabellidae now consists of the subfamilies; Myxicolinae and Sabellinae.•Myxicolinae contains two tribes, named herein as Amphiglenini and Myxicolini.•Analysing more genes results in a more stable sabellid phylogeny with higher support.•Higher divergence genes better resolve the sabellid relationships. Sabellida is a well-known clade containing tube-dwelling annelid worms with a radiolar crown. Iterative phylogenetic analyses over three decades have resulted in three main clades being recognized; Fabriciidae, Serpulidae and Sabellidae, with Fabriciidae proposed as the sister group to Serpulidae. However, relationships within Sabellidae have remained poorly understood, with a proliferation of genera. In order to obtain a robust phylogeny with optimal support, we conducted a large-scale phylogenomic analysis with 19 new sabellid transcriptomes for a total of 21 species. In contrast to earlier findings based on limited DNA data, our results support the position of Fabriciidae as sister taxon to a Sabellidae + Serpulidae clade. Our large sampling within Sabellidae also allows us to establish a stable phylogeny within this clade. We restrict Sabellinae to a subclade of Sabellidae and broaden the previously monotypic Myxicolinae to include Amphicorina and Chone. We tested the robustness of species tree reconstruction by subsampling increasing numbers of genes to uncover hidden support of alternative topologies. Our results show that inclusion of more genes leads to a more stable topology with higher support, and also that including higher divergence genes leads to stronger resolution.