Trauma, I was just responding to Twitch's post. Here, I'll rephrase:
"True that, like how a poodle and German Shephard are not similar, you may think Piranhas and Tetra's are very different. However, in my experience, tetras exhibit many of the same kind of aggressive traits as Piranhas, despite their difference in reputations. The biggest difference, to me, seems to be size and weapons. The piranhas get much larger than tetras and have razor edge teeth. The tetras do not. I would assume (I may be wrong, however) that this similarity in behavior is due to belonging to the same family of fish."
I didn't post all that because I was just saying, you know, hey, here's my experience. But next time I'll be sure to be explicit in order to avoid any future confusion.