To interpret the orthofinder output file Orthogroups.csv, if I have three input protein fasta file, the output Orthogroups.csv is like below, the first two species have no reference genome, so its' ID looks like"Trinity_DN_...", since the ID has similar format for the first two species( Clarias, Pan), how could I identify if they are from the first species (Clarias) or third species (Pan)..
if the IDs used in each set are not unique you likely will run into trouble (I'm already surprised that blast did not complain on this?). Before running orthofinder it's a good idea to prefix the IDs from each set with a 'code' that indicates the species it's from.
By using the newer version, the members of your first two species (Clarias, Pan) will be separated by a tab and appear in the second and third columns of "Orthogroups.tsv", so you can identify them by selecting a specific column regardless of the naming.
Just following on from what SMK said, the Orthogroups.csv file was also a tab-delimited file. Genes from difference species are separated by a tab and genes within the same species are separated with a comma. If you open it in a spreadsheet program (e.g. Excel, LibreOffice Calc) and chose 'tab' as the delimiter then it will display correctly.
if the IDs used in each set are not unique you likely will run into trouble (I'm already surprised that blast did not complain on this?). Before running orthofinder it's a good idea to prefix the IDs from each set with a 'code' that indicates the species it's from.
I think OrthoFinder does the conversion before running BLAST for you, for example in the WorkingDirectory I got: