Oscars and P's go together like acids and bases, the same thing with only having to Ps.
You should never have only to Ps as there is nothing to dilut the agression, 1 p okay, 3-one million Ps okay, 2ps no good.
anyway piranah of the pygocentrus genre are loose shoaling at best, they will always batlle over food, dominance, territroy, mates and just plain nipping. dont besurprised when one gets wounded in battle, after all every one knows the old saying, it all fun and games till someone loses an eye. which is not all a to uncommon in a shoal of ps
QUinn