will depend on the jag, and remember, its a cichlid, so no matter how docile it may seem, that could change at any time.
that said, i have a 4-5" or so jag in my 250 who does basically nothing all day long, dont bother my small bichirs, and barely pays attention to ghost shrimp unless the thing literally walks infront of its mouth
however everyday i go down, i check to see if all poly's are still alive, and dident look like a giant worm to a cichlid.