Taxonomic revision of Eudesme (Ectocarpales s.l., Phaeophyceae) proposing a new species E. borealis sp. nov.

ABSTRACT

Molecular phylogeny of Eudesme specimens collected from various localities in the Northern Hemisphere using mitochondrial cox1 and cox3 and chloroplast atpB, psaA, psbA and rbcL gene sequences revealed an undescribed species in the genus. In the analyses, three distinct clades (clades 1, 2 and 3) with high statistical supports were recognised. Specimens of clade 1 corresponded to the generitype E. virescens because the morphology agreed with the reported descriptions of the species, and the distribution (subboreal Europe) included the type locality. Clade 2 had a broad distribution in the Arctic Sea and coldwater regions of the northern Pacific and northern Atlantic. Specimens of clade 2 were morphologically distinguishable from E. virescens in having broader sporophytes. Specimens of clade 3 collected from western Honshu, Japan, had cox3 sequence identical to one of an old voucher specimen of E. shandongensis (63-519) described from the Yellow Sea. We propose the establishment of a new species, E. borealis, distributed in the Arctic, northern Pacific, and northern Atlantic regions.

KEYWORDS:

• Chordariaceae
• Eudesme borealis sp. nov.
• Eudesme shandogensis
• Eudesme virescens
• Multigene molecular phylogeny
• Taxonomy

ACKNOWLEDGEMENTS

We are grateful to Dr Eric C. Henry for his valuable comments on the article and to Drs Viviana Peña Freire, Michael D. Guiry, Nils T. Hagen, Svenja Heesch, and Nina Klochkova for their help in collecting specimens.

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