I am newbie to the site although I have had catfish for awhile. By the way, just love the Cat-eLog

At present I have:
1 spotted raphael cat
5 synodontis petricola
5 synodontis multipunctatus
3 parotinclus
a number of otocinclus
and now, 2 cory cats (they were a rescue from someone who was tearing his/her tanks down).
They are the ones I have a question about. I would like to get them some buddies because I know they like to shoal. However, do the other corys have to be the same species or will they be happy shoaling with other species.
I appreciate any help you can give me.