Unfortunately, I woke up and found the Jar dead with no apparent marks or bruises, so even though he looked good yesterday I think he was stressed from shipping.
Not to bump an old topic but anyone out there that is wondering, I can't think of any fish that could be kept with the Brycon. The one I had really messed with my GATF and every other fish in the tank. Maybe a wolf fish or something would work but be prepared that these guys are aggressive.