Memorias de la RSEHN (segunda época)

Several samples collected at different sites of the Alboran Sea following a west-east gradient from the Strait of Gibraltar (SoG) were analyzed by metabarcoding of the V9 region of the18S rRNA ribosomal gene. The analysis permitted identifying 9601 operational taxonomical units (OTUs) of protists, at least until class level, which were classified into four supergroups (Excavata, SAR, Unikonta and Archaeplastida) and 63 deep-branching eukaryotic lineages. Dinoflagellates was the group showing the highest biodiversity, followed by Syndinales (17% of OTUs) and diatoms (4.5%). The high biodiversity of non-free living forms (Syndiniales) as well as other heterotrophs with varied feeding modes, including ciliates, small flagellates and fungi (saprophyte), evidence a relatively elevated variety of trophic modes within the communities. The relative abundance of some groups changed with the distance from the SoG. In particular, relative abundances of phototrophic diatoms, Chrysophyceae and Haptophyta, and of heterotrophic ciliates and radiolarians decreased towards the east. In contrast, dinoflagellates abundance increased following the west-east gradient. These differences illustrate that the composition of the plankton communities at the eastern side of the SoG is distinguishable from the rest of the Alboran Sea.

La técnica de secuenciación masiva de la región V9 del gen ribosomal 18S fue aplicada en muestras recogidas en diferentes estaciones del mar de Alborán siguiendo el gradiente oeste-este desde el estrecho de Gibraltar (EdG). Estos análisis permitieron identificar 9601 unidades taxonómicas operacionales (UTOs) de protistas a nivel de clase. Los UTOs fueron clasificados en cuatro supergrupos (Excavata, SAR, Unikonta y Archaeplastida) y 63 líneas evolutivas de eucariotas. Los dinoflaglelados fueron el grupo que presentó mayor diversidad,