Suchergebnisse

The Atlantic-Mediterranean marine transition is a fascinating biogeographic region, but still very poorly studied from the point of view of seaweed phylogeography. Dictyota fasciola and D. mediterranea (Dictyotales, Phaeophyceae) are two currently recognized sister species that share a large part of their distribution along the Mediterranean Sea and the Atlantic Ocean, representing a unique study model to understand the diversification processes experienced by macroalgae during and after Messinian at this marine region. In this study, we sampled 102 individuals of D. fasciola and D. mediterranea from 32 localities along their distribution range and sequenced the mitochondrial cox1 and the chloroplast rbcL-rbcS DNA regions for all the samples. Our data do not support the occurrence of two sister species but a morphologically variable and highly genetic diverse species or a complex of species. Most of the observed genetic diversity corresponds to the Mediterranean populations, whereas the Atlantic ones are much more homogeneous. The early-diverged lineages inferred from both mtDNA and cpDNA phylogenetic reconstructions were constituted by samples from the Mediterranean Sea. Together, these results suggest that the Mediterranean Sea acted as a refugium for the D. fasciola–D. mediterranea lineage during the geologic and climatic changes occurred on the region since the Miocene, subsequently dispersing to the Atlantic Ocean. ; Financial support was provided by Fundación Biodiversidad and the Catalan government (project 2014SGR514). ; Peer reviewed

9 páginas, 17 figuras ; [EN]The presence of Dictyota ciliolata (Dictyotales, Phaeophyceae) on the coasts of the Iberian Peninsula is reported. D. ciliolata is a tropical to subtropical species mainly distributed along the coasts of the Atlantic and Indian oceans. Although it occurs in areas next to the Mediterranean, like the Red Sea and the Atlantic coasts of Morocco, Canary Islands and Madeira, D. ciliolata had not been previously reported from the Mediterranean Sea. A morphological and anatomical comparison of the Iberian specimens of this species with those of other geographical areas, as well as with other similar species of Dictyota occurring in the Mediterranean Sea, is provided.[FR]Dictyota ciliolata est une espèce tropicale-subtropicale qui se trouve principalement sur les côtes des océans Atlantique et Indien. Bien que déjà signalée des zones proches de la Méditerranée, telles la Mer Rouge et les côtes Atlantiques du Maroc, des Canaries et de Madère, D. ciliolata n'avait pas été rapportée en Méditerranée ; elle est, ici, signalée sur les côtes de la Péninsule Ibérique. La morphologie et l'anatomie des individus de D. ciliolata de la Péninsule Ibérique sont comparées avec celles de spécimens d'autres zones géographiques, ainsi qu'avec d'autres espèces de Dictyota de la Méditerranée. ; This work was supported by the projects PB90-0461-C02-01 and REN2001-1473-C03-03/GLO of the Spanish Government, and the Agència Catalana de l'Aigua (Generalitat de Catalunya). ; Peer reviewed