Fluorescence micrographs of rappemonads in the North Pacific. The nucleus (blue) was often slightly elongated with a tapering end. Two to four plastids (green) appeared to be present per cell.
Like I said, the use of modern molecular methodology is allowing us to look at microbes within the oceans in ways never before possible and this is leading to some amazing discoveries - not just new twigs on the tree of life but major new branches we did not even know existed. This paper, in PNAS, last week has a fairly self-descriptive title:
Newly identified and diverse plastid-bearing branch on the eukaryotic tree of life
Here, we report a newly discovered uncultured plastid-bearing eukaryotic lineage named the rappemonads.
Environmental DNA sequencing revealed extensive diversity at North Atlantic, North Pacific, and European freshwater sites, suggesting a broad ecophysiology and wide habitat distribution.
The rappemonads are unique, widespread, putatively photosynthetic algae that are absent from present-day ecosystem models and current versions of the tree of life.