Organisms Diversity & Evolution

, Volume 16, Issue 1, pp 73–84 | Cite as

Interrelationships of Nemertodermatida

  • Inga Meyer-Wachsmuth
  • Ulf JondeliusEmail author
Original Article


Nemertodermatida is a small taxon of microscopic marine worms, which were originally classified within Platyhelminthes. Today they are hypothesized to be either an early bilaterian lineage or the sister group to Ambulacraria within Deuterostomia. These two hypotheses indicate widely diverging evolutionary histories in this largely neglected group. Here, we analyse the phylogeny of Nemertodermatida using nucleotide sequences from the ribosomal LSU and SSU genes and the protein coding Histone 3 gene. All currently known species except Ascoparia neglecta and Ascoparia secunda were included in the study in addition to several yet undescribed species. Ascopariidae and Nemertodermatidae are retrieved as separate clades, although not in all analyses as sister groups. Non-monophyly of Nemertodermatida was rejected by the Approximately Unbiased test. Nemertodermatid nucleotide sequences deposited in Genbank before 2013 were validated against our dataset; some of them are shown to be chimeric implying falsification of prior hypotheses about nemertodermatid phylogeny: other sequences should be assigned new names. We also show that the genus Nemertoderma needs revision.


Nemertodermatida LSU SSU Molecular phylogeny Cryptic species Approximately Unbiased test 



We would like to thank Ms Keyvan Mirbakhsh for her work in the molecular lab. We are also grateful to the staff at the Sven Lovén Centre for Marine Sciences, Dr Ana Amaral at CCMAR, Faro, Ms Lisa Del Monte, ISZN, Naples, with colleagues and Ms Margret Krüß, BAH, Helgoland, with colleagues for help with our fieldwork. We would also like to express our gratitude to Prof. Mark Martindale then of the University of Hawaii Kewalo Marine Lab. Furthermore, are we indebted to the Professor Philippe Bouchet of the Muséum National d’Histoire Naturelle for organizing sampling in Papua New Guinea. Collections in Papua Guinea took place during the Our Planet Reviewed Papua Niugini Expedition in November–December 2012, organised by the Muséum National d’Histoire Naturelle (MNHN), Pro Natura International, the Institut de Recherche pour le Développement (IRD) and the University of Papua New Guinea. The principal investigators of this expedition were Philippe Bouchet, Sarah Samadi (MNHN) and Claude Payri (IRD), and funding was provided by the Total Foundation, Prince Albert II of Monaco Foundation, Foundation EDF, Stavros Niarchos Foundation and Entrepose Contracting, with support from the Divine Word University and operated under a permit delivered by the Papua New Guinea Department of Environment and Conservation. Financial support from the Swedish Research Council to UJ is gratefully acknowledged (grant numbers 2009–5147 and 2012–3913) as are the stipends by Föreningen Riksmusei Vänner (stipend 2011), Stiftelsen Lars Hiertas Minne grant FO2011-0248 and the Royal Swedish Academy of Sciences grant FOA11H-352 to I. Meyer-Wachsmuth.

Supplementary material

13127_2015_240_MOESM1_ESM.xls (92 kb)
Online Resource 1 Observed nucleotide frequencies and GC-content per specimen for all three genes used in this study and the codon positions of the protein-coding gene Histone 3. Species names highlighted in red have greatly varying sequence lengths, which may have affected the observed nucleotide bias (XLS 92 kb)
13127_2015_240_MOESM2_ESM.xls (89 kb)
Online Resource 2 The estimates of the disparity index for all three genes. The Disparity Indices per-site are shown for each sequence pair above the diagonal. Below, the p values of the Disparity Indices are shown, those smaller than 0.05 are considered significant. Evolutionary analyses were conducted in MEGA5.2.2. (XLS 89 kb)
13127_2015_240_MOESM3_ESM.jpg (1.5 mb)
Online Resource 3 Comparison of the topologies of trees estimated from the original (left) and Aliscore-reduced (right) SSU datasets. The differing nodes are marked (JPEG 1503 kb)
13127_2015_240_MOESM4_ESM.pdf (104 kb)
Online Resource 4 Saturation plots for all three genes used in this study and for the codon positions of H3. Histone 3, and especially its 3rd codon position, show patterns indicating saturation (PDF 103 kb)
13127_2015_240_MOESM5_ESM.pdf (607 kb)
Online Resource 5 Gene trees for LSU, SSU and H3. Maximum Likelihood (ML) trees were estimated with RAxML and Bayesian inferences (MB) were performed with MrBayes. The colours correspond to genera, and in case of Ascopariidae to the family. a) ML LSU. b) MB LSU. c) ML SSU. d) MB SSU. e) ML H3. f) MB H3 (PDF 606 kb)
13127_2015_240_MOESM6_ESM.xlsx (86 kb)
Online Resource 6 Pairwise distances across the a) LSU, b) SSU and c) Histone 3 gene datasets (XLSX 85 kb)


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Copyright information

© Gesellschaft für Biologische Systematik 2015

Authors and Affiliations

  1. 1.Department of ZoologySwedish Museum of Natural HistoryStockholmSweden
  2. 2.Department of ZoologyStockholm UniversityStockholmSweden
  3. 3.Institute of ParasitologyBiology Centre of the Czech Academy of SciencesČeské BudĕjoviceCzech Republic

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