DADA2 rep seqs have strange names. Why?

[ChrisKeefe]

Split from here:

Errors in the pipeline of DADA2, Fearture-table merge-seqs, and phylogeny align-to-tree-mafft-fasttree.

Thanks for putting together such a clear and detailed question, @Moon! Good sleuthing ! This is, indeed, an out of memory error. Here’s an experiment you can try. Sometimes when parallelizing processes, each thread contributes a significant amount of memory usage. If you’re running out of memory, try decreasing the number of threads to 4. If it still gives you OOM errors, you can try dropping the number of threads even farther. Overall, this will likely mean a longer run time…