When the earth was young, and dinosaurs walked the land...I worked in a pet shop after school. The boss kept a large tank with a display group of RB Piranhas and they bred fairly regularly. The young were easily raised on brine shrimp, grew quickly and sold just as quickly, since they were priced so cheaply. The adults were a typical motley group of piranhas...chewed fins, missing eyes, war wounds everywhere...and as the youngsters grew they started to look pretty tough as well. I recall we periodically netted out the largest fry and placed them into the For Sale tank, to give the smaller ones a chance to survive.
Just to clarify: the owner didn't set out to breed these fish. He just gave them space, good water and good food, and then let nature take its course.
