10.6084/m9.figshare.4519703.v1 Frederique Steen Frederique Steen Joana Aragay Joana Aragay Ante Zuljevic Ante Zuljevic Heroen Verbruggen Heroen Verbruggen Francesco Paolo Mancuso Francesco Paolo Mancuso Francis Bunker Francis Bunker Daniel Vitales Daniel Vitales Amelia Gómez Garreta Amelia Gómez Garreta Olivier De Clerck Olivier De Clerck Tracing the introduction history of the brown seaweed <i>Dictyota cyanoloma</i> (Phaeophyceae, Dictyotales) in Europe Taylor & Francis Group 2017 Alien species cryptogenic species Dictyota cyanoloma herbarium species mitochondrial DNA 2017-01-05 10:31:14 Journal contribution https://tandf.figshare.com/articles/journal_contribution/Tracing_the_introduction_history_of_the_brown_seaweed_i_Dictyota_cyanoloma_i_Phaeophyceae_Dictyotales_in_Europe/4519703 <p><i>Dictyota cyanoloma</i> has recently been described from the Mediterranean Sea and Macaronesia but doubt had arisen as to whether this species was truly native in Europe. The species is mainly found on non-natural substrata (harbour walls, marinas, boat hulls, etc.), strongly suggesting that it is an introduction. Molecular sequence information from historical herbarium samples proves the presence of <i>D. cyanoloma</i> in the Adriatic Sea as early as 1935. Since approximately the year 2000, however, the number of records as well as the geographic range of the species has expanded significantly. The present-day distribution of <i>D. cyanoloma</i> occupies most of the Mediterranean Sea, Macaronesia, NW Africa and southern Portugal, but recent records from Galicia and SW England (Falmouth, Cornwall) indicate that the species is rapidly expanding northward. Collections from Australia demonstrated that the species is also present from Perth in Western Australia, over much of the southern Australian coastline up to Minnie Water in New South Wales. Phylogenetic analyses resolve <i>D. cyanoloma</i> in a sister clade to a previously unreported Australian <i>Dictyota</i> species. Analysis of genetic diversity of the mitochondrial markers (<i>nad</i>6–<i>nad</i>11 and <i>atp</i>9–<i>orf</i>11) reveals that even though Australian populations contain a much higher haplotype richness, European populations are also fairly diverse. Furthermore, only two out of 25 haplotypes are shared between both regions. These somewhat counterintuitive results could be indicative of a more complicated introduction history.</p>