well you could always try it ... as long as you raise them from young together and fedd em plenty with my experiences as long as we are talking RBP or similar you syhould do ok mixing them P with memegers of teh subfamily ... just my opinion...make sure you feed plenty though
Exodon paradoxus have tuberculate teeth that are quite formitable for removing scales of fishes. I have a drawing at my web site under Other Predatory fishes which some interesting breeding information. This page might be of some use to you.
I just got a good deal on some Exodons (2 for 10 bucks). So i threw them in the tank with my cariba and RBPs. They are just so fast not one of my piranhas can catch up to them. They have stayed alive just fine for a week now. Unless they make a mistake and swim in front of the big cariba, they will be alive for a long time.
I think success depends on tank size and setup. Honestly, for those who have claimed that it was a waste of money, how big was your tank? Most unsuccessful attempts that I have read about were in tanks that were less than 100 gallons.
I have kept 20 exos in a 180 mixed pygo tank with success for about a year. The tank had plenty of open space for the exos to swim and the pygos really never seemed to be interested in them anyways. Of course, they were well fed...
The reason for their death was due to an extended blackout that lasted more than a day. The pygos were lethargic but the exos were dead.
i too had success with Exos in a tank with my RBs before. 10 Exos in a tank of 4 5" RBs in a 125 gal. All were eatten though after purchasing 7"+ Rbs afterwards. 2 were housed in with my Rhom which were eatten with a couple hrs.