title: Re-evaluating the phylogeny of Sipuncula through transcriptomics.
abstract: Sipunculans (also known as peanut worms) are an ancient group of exclusively marine worms with a global distribution and a fossil record that dates back to the Early Cambrian. The systematics of sipunculans, now considered a distinct subclade of Annelida, has been studied for decades using morphological and molecular characters, and has reached the limits of Sanger-based approaches. Here, we reevaluate their family-level phylogeny by comparative transcriptomic analysis of eight species representing all known families within Sipuncula. Two data matrices with alternative gene occupancy levels (large matrix with 675 genes and 62% missing data; reduced matrix with 141 genes and 23% missing data) were analysed using concatenation and gene-tree methods, yielding congruent results and resolving each internal node with maximum support. We thus corroborate prior phylogenetic work based on molecular data, resolve outstanding issues with respect to the familial relationships of Aspidosiphonidae, Antillesomatidae and Phascolosomatidae, and highlight the next area of focus for sipunculan systematics.
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA. Electronic address: sarah.lemer@gmail.com.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lemer
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA; CEBIMar, Universidade de São Paulo, Praia do Cabelo Gordo, São Sebastião, São Paulo, Brazil.
authors.forename: Gisele Y
authors.initials: GY
authors.lastname: Kawauchi
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA; Departamento de Zootecnia, ESALQ-USP, Piracicaba, São Paulo, Brazil.
authors.forename: Sónia C S
authors.initials: SC
authors.lastname: Andrade
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA; Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.
authors.forename: Vanessa L
authors.initials: VL
authors.lastname: González
authors.affiliation: Smithsonian Tropical Research Institute (STRI), Naos Marine Laboratories, Panama 0843/03092, Panama.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Boyle
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Giribet
mesh_terms: D000818:Animals; D015723:Gene Library; D016013:Likelihood Functions; D008957:Models, Genetic; D010802:Phylogeny; D011077:Polychaeta / Q000145:classification*; D017422:Sequence Analysis, DNA; D059467:Transcriptome
keywords: Annelida; Peanut worms; Phylogenomics; Systematics