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Recent speciation and hybridization in Icelandic deep-sea isopods: an integrative approach using genomics and proteomics
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  • Eva Paulus,
  • Saskia Brix,
  • Annabelle Siebert,
  • Pedro Martínez Arbizu,
  • Sven Rossel,
  • Janna Peters,
  • Jörundur Svavarsson,
  • Martin Schwentner
Eva Paulus
University of Groningen

Corresponding Author:[email protected]

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Saskia Brix
Senckenberg am Meer
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Annabelle Siebert
Senckenberg am Meer
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Pedro Martínez Arbizu
Senckenberg Research Institute
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Sven Rossel
Senckenberg am Meer
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Janna Peters
Senckenberg am Meer Deutsches Zentrum für Marine Biodiversitätsforschung
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Jörundur Svavarsson
University of Iceland
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Martin Schwentner
Naturhistorisches Museum Wien
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The isopod species Haploniscus bicuspis (G.O. Sars, 1877) shows circum-Icelandic distribution in a wide range of environmental conditions and along well-known geographic barriers, such as the Greenland-Iceland-Faroe (GIF) Ridge. We wanted to explore population genetics, phylogeography and cryptic speciation as well as to investigate whether previously described, but unaccepted subspecies have any merit. Using the same set of specimens, we combined mitochondrial COI sequences, thousands of nuclear loci (ddRAD), and proteomic profiles, plus selected morphological characters using Confocal Laser Scanning Microscopy (CLSM). Five divergent genetic lineages were identified by COI and ddRAD, two south and three north of the GIF Ridge. Assignment of populations to the three northern lineages varied and detailed analyses revealed hybridization and gene flow between them, suggesting a single northern species with a complex phylogeographic history. No apparent hybridization was observed among lineages south of the Ridge, inferring the existence of two more species. Differences in proteomic profiles between the three putative species were minimal, implying an ongoing or recent speciation process. Population differentiation was high, even among closely associated populations, and higher in mitochondrial COI than nuclear ddRAD loci. Gene flow is apparently male-biased, leading to hybrid zones and instances of complete exchange of the local nuclear genome through immigrating males. This study did not confirm the existence of subspecies defined by male characters, which probably characterize different male developmental stages present in all species.
17 Mar 2021Submitted to Molecular Ecology
19 Mar 2021Submission Checks Completed
19 Mar 2021Assigned to Editor
06 Apr 2021Reviewer(s) Assigned
23 Jun 2021Review(s) Completed, Editorial Evaluation Pending
25 Jun 2021Editorial Decision: Revise Minor
26 Aug 20211st Revision Received
26 Aug 2021Review(s) Completed, Editorial Evaluation Pending
31 Aug 2021Editorial Decision: Revise Minor
06 Oct 2021Review(s) Completed, Editorial Evaluation Pending
06 Oct 20212nd Revision Received
11 Oct 2021Editorial Decision: Accept
Jan 2022Published in Molecular Ecology volume 31 issue 1 on pages 313-330. 10.1111/mec.16234