Why does he want to know, when he himself admits he has none, that it's just out of curiosity?
Well, out of curiosity, I would say that depending on the size of the Fahaka, those p's would be dead. Fahakas are very agressive and lightning quick.
( Strangely I have 2 together that get along well )
With big Piranhas, in a shoal , the fahaka would probably be killed in a gruesome way.
I detest this type of threads and questions, just out of curiosity...