Elucidating the phylogeny and taxonomic position of the genus Spiniferomo- nas Takahashi (Chrysophyceae)

Spiniferomonas represents a strictly single-celled plastid-bearing genus of silica-scaled chrysophytes, with a well-characterised morphology and ultrastructure, as well as a pretty known ecology based on scale records. However, the taxonomic status of this genus remains ambiguous due to the absence of relevant sequence data. Spiniferomonas has historically been classified in the Synurales, Paraphysomonadales, or Chrysosphaerellaceae based upon interpretations of the silica scale morphology. In this study, we have aimed to genetically characterize a newly established Spiniferomonas trioralis culture as well as culture of unicellular Chrysosphaerella coronacircumspina to elucidate the taxonomy of Spiniferomonas and to resolve the relationship between the two genera. Using SSU rDNA and rbcL concatenated sequences, we show that Spiniferomonas and Chrysosphaerella are sister taxa in a well-supported monophyletic lineage of silica-scaled chrysophytes within the order Chromulinales.

Automated summary

This study genetically characterizes Spiniferomonas and Chrysosphaerella, two genera of silica-scaled chrysophytes, and reveals their relationship as sister taxa within the order Chromulinales.