Planktonic protist diversity across contrasting Subtropical and Subantarctic waters of the southwest Pacific

Metabarcoding reveals marked seasonality and a distinctive winter assemblage of dinoflagellates at a coastal LTER site in the Gulf of Naples

“…The high-relative abundance of Syndiniales in the winter months in the Gulf of Naples was already noticed in a previous study, where this group of Alveolata accounted for about 50% of the protist community in December (Piredda et al, 2017). In the present study, the marked differences in Syndiniales composition among the seasons are in agreement with the variability in clade dominance reported among different environments and seasons (e.g., Anderson & Harvey 2022;Clarke et al, 2019;Gutierrez-Rodriguez et al, 2022;Sehein et al, 2022). As Syndiniales clades could include many different species, and their abundance presumably reflects the presence of specific hosts, appropriate network analyses involving the whole communities could help unveiling such complex relationships among species inhabiting the water column.…”

From the Sunlit to the Aphotic Zone: Assembly Mechanisms and Co-Occurrence Patterns of Protistan-Bacterial Microbiotas in the Western Pacific Ocean

“…Similar to the bacterial community, the protistan community in the present study was clearly stratified down the water column, demonstrating a large vertical difference between photic and aphotic protistan-bacterial microbiomes in the western Pacific. Recent studies, including those on protistan communities at station ALOHA in the North Pacific Subtropical Gyre ( 45 ), in the subtropical and subantarctic waters of the southwest Pacific ( 46 ), and in the tropical and subtropical global oceans ( 32 ), support this conclusion. The dichotomy in distribution of protists and bacteria along the water column observed in the present study and at both local and global scales likely underlies the heterogeneity of biotic, abiotic, and dispersal conditions encountered in photic and aphotic zones, and this variation in biotic, abiotic, and dispersal conditions may be a crucial factor that can directly influence community composition.…”

“…Clone libraries, fingerprints, high-throughput sequencing, and metagenomics have revealed differential patterns of bacterial communities that occur in photic versus aphotic zones in a vast array of marine environments ( 35 , 37 – 45 ). Observational data on the vertical distribution of FL and PA bacteria are abundant, whereas data on protists, particularly below the photic zone, are lacking ( 32 , 45 , 46 ). Similar to the bacterial community, the protistan community in the present study was clearly stratified down the water column, demonstrating a large vertical difference between photic and aphotic protistan-bacterial microbiomes in the western Pacific.…”

The Mixoplankton Database (MDB): Diversity of photo‐phago‐trophic plankton in form, function, and distribution across the global ocean

“…The proliferation of global‐scale metabarcoding studies documenting distributions of organisms according to DNA‐based analyses, usually 18S rRNA gene sequences (e.g. TARA Oceans, Malaspina, as well as many local and regional‐scale surveys; Caracciolo et al, 2022; de Vargas et al, 2015; Gutiérrez‐Rodríguez et al, 2022; Hu et al, 2016; Massana et al, 2015), is greatly expanding our knowledge of plankton distributions. This could potentially allow us to quantify the global extent of mixoplankton importance in the ocean's food web.…”