A lot of questions on other forums have asked the question incorrectly. What is the "most aggressive" piranha or what is the meanest piranha? It seems to me that for better or for worse there is an unaswered but not unanswerable question out there. What is the most powerful piranha? I have heard a littany of anecdotes about rhoms either being unbeatable or wimps. Likewise anecdotes about elongatus being the most aggressive piranha but being killed by geryi, etc. Other speculation that pygo jaw strength is inherrently stronger than serras. It seems to that status, i.e. who is the baddest piranha out there is what people are looking for. And that doesn't mean the most aggressive and it doesn't mean the largest. It means simply that at maturity in a head to head, which species of piranha is the most powerful, i.e. combining size and aggression, would come out on top. Piraya? Maybe. Manuelis and rhoms get pretty good size too. Elongatus are aggressive but are limited to 12" so how can they be the baddest, most powerful piranha. Beautiful fish. But if we cut to the chase, the "it depends on the individual fish" isn't really a satisfying answer. And given what we know about the maximum size of a piranha species and the aggression of that species, it doesn't seem like that diffcult a question to answer. Nor do I claim to. But seems like we are talking about Caribes, rhoms, pirayas, manuellis and not elongatus, natteri, hollandi, etc. Thoughts?