Diversidad del complejo laurencia (rhodophyta, ceramiales) en macaronesia

Résumé

The Laurencia complex currently encompasses six genera: Laurencia, Osmundea, Chondrophycus, Palisada, Yuzurua and Laurenciella. Several morpho-anatomical and reproductive characters used in the taxonomy of the complex are of diagnostic value only at the generic level; however, identification of species based on these features is extremely difficult due to phenotypic plasticity and overlaps in many morphological characters, which complicates and remains confusing the taxonomy of the group. In this context, molecular markers have proven useful in delimiting taxa of the Laurencia complex and inferring their phylogenetic relationships. In the present study we investigate the diversity of the Laurencia complex in the Azores, Madeira, Savage and Canary Islands, Atlantic oceanic archipelagos, which belong to the same ecoregion, Lusitanian province of the Macaronesian region. We undertake an integrative approach, using morphological, molecular (COI-5P, rbcL and LSU markers) and chemical data (CE-MS), to delineate species, infer and interpret their phylogenetic relationships, disentangle the taxonomy and define the distribution and biogeographic affinities of the members of the complex in the Macaronesian islands, where speciation events are supposedly common leading to a high endemicity. Based on obtained results, 16 species of the Laurencia complex are delimited and confirmed for the Macaronesian coastline, of which two are newly described species. The taxonomic statuses of 16 records remain uncertain (are not DNA or morphologically confirmed), until further investigation is carried out to shed light on species boundaries of this complex.