Dendrogram of diatom genera. Dendrogram showing species as listed in Viličić et al. (2002) as recovered from all published and observed data until 2002, representing a potential diatom diversity observable in the eastern northern Adriatic. Genetic diversity acquired in this study is compared to genera found in the checklist (2002). Species recovered from metabarcoding data, but so far absent from the 2002 checklist, were added to the dendrogram: Filled purple dots at the tip points indicate diatom genera obtained with metabarcoding, while orange dots present metabarcoded genera that were not present in a checklist. The bubble plot shows the number of morphospecies from the checklist (column Species) and the number of different clustering units assigned per genera depending on the clustering method (columns ASVs, 99%-OTUs, 97%-OTUs) and removal of low abundant clustering units (columns ASVs*, 99%-OTUs*, 97%-OTUs*). The bar plot on the right showing the contribution of species/clusters for each genus/clustering method. Genera not found in metabarcoding data were left out. The bottom bar plot indicates the number of morphospecies (first column) and clustering units (other columns) generated by each clustering method for the diatom group.