Bifidochaetus, a new Arctic genus of freshwater Chaetonotida (Gastrotricha) from Spitsbergen revealed by an integrative taxonomic approach
Małgorzata Kolicka A E , Miroslawa Dabert B , Jacek Dabert C , Tobias Kånneby D and Jacek Kisielewski AA Department of Animal Taxonomy and Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61–614 Poznan, Poland.
B Molecular Biology Techniques Laboratory, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61–614 Poznań, Poland.
C Department of Animal Morphology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, 61–614 Poznań, Poland.
D Department of Zoology, Swedish Museum of Natural History, PO Box 50007, SE–104 05 Stockholm, Sweden.
E Corresponding author. Email: kolicka@amu.edu.pl
Invertebrate Systematics 30(4) 398-419 https://doi.org/10.1071/IS16001
Submitted: 1 January 2016 Accepted: 14 April 2016 Published: 31 August 2016
Abstract
Gastrotricha is a cosmopolitan phylum of aquatic and semi-terrestrial invertebrates that comprises ~820 described species. To date, freshwater gastrotrichs have not been the subject of faunistic or taxonomic research in the polar regions. In this paper, we present the first species-level description of a freshwater gastrotrich from the Arctic (Svalbard Archipelago). Evidence from morphology, morphometry and molecular analyses reveals that the species represents a new genus in Chaetonotidae: Bifidochaetus arcticus, gen. et sp. nov. Taking into consideration many morphological similarities to Chaetonotus (Primochaetus) veronicae Kånneby, 2013 we propose to include C. (P.) veronicae in the newly established genus under the new combination Bifidochaetus veronicae (Kånneby, 2013), comb. nov. In the phylogenetic analysis based on nuclear 18S rRNA, 28S rRNA and mitochondrial cytochrome c oxidase subunit I sequence data, B. arcticus, gen. et sp. nov. is nested within the family Chaetonotidae, as the sister group to the genus Lepidochaetus Kisielewski, 1991. In this paper we also present new taxonomic characters useful for gastrotrich taxonomy: the pharynx-to-intestine length ratio (I) and the spine bifurcation ratio (B).
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