they get along great... as soon as i see its fins starting to disapear ill take him out... but right now they are great... what do u guys feed them??
The bichirs or pirhanas lol? Seriously though, I keep both RBP's and bichirs, and I urge you to move your piranhas or fish to a dif tank as they will bite/kill it one day, you might not be there to see it. They eat scales of other fish in the wild so your just tempting them and gonna get your poor other fish stressed and killed.
As for the bichirs they are predatory too so dont keep them with anything small. They are great fish and are hand feed easily. just be careful with your fingers

I have 2 senegals, 1 that is albino and I feed them on pellets, frozen krill, frozen beefheart, and strips of lancefish. Dont use feeder fish with your bichir, its unnecessary and it will just get sick one day. Dont waste your money on feeders ever for that matter.
Be sure not to overfeed, 1 large meal a day once every 2-3 days is fine for bichirs, when in doubt, underfeed. After feeding you will see their stomachs stay very fat and full for a few days. I agree the vision isnt the best, but they dont need it at night and will take out small fish in no time so dont be fooled.
Good luck and do us and your fish a favor and isolate those RBP
Drew