I trained a classifier on the reads (v3v4) from the latest Silva database and got this bacteria:
D_0__Bacteria;D_1__Planctomycetes;D_2__Planctomycetacia;D_3__Pirellulales;D_4__Pirellulaceae;D_5__Pir4 lineage;D_6__Symbiodinium sp. A1
Is it an error in the database? Symbiodinium is an Eukaryota. When I blasted a DNA sequence I found only uncultured bacteria on the NCBI blastn.
It’s possible? I think it might be best to contact the team behind Silva. They can probably better address the issue.
BTW, I moved this to “general discussion”, since it’s not directly related to QIIME.