Welcome to the forum.
Profile says feeder fish because it’s just a ranking system based on post count etc.
Make sure the store has them first!
I assume you are talking about red bellied piranhas (pygocentrus nattereri)?
Red bellied piranhas are extremely hardy, so I wouldn’t worry about it dying in transport unless it was subjected to extreme abuse (too cold, hot, bag shaken like the scene in Nemo). I’ve taken puffers (notoriously easy to kill) in a 3 hour car ride without any issues.
Piranhas of the pygocentrus genus like schools, but it has to be in groups of at least 3-5+ for that to work. Two will constantly fight, with the dominant one harassing the weaker one. Inevitably buying two will leave you with one.
40 gallons is a bare minimum because piranhas are quite inactive, but a 12 inch fish would be much happier in a 75 gallon (extra foot long and extra 6 inches wide). Mine was in a 60 and actually died because it got scared and rammed headfirst into the glass (tankmate was a banded leporinus... mean as hell. I don’t recommend keeping piranhas with other types of fish because it causes a lot of stress on both). I’d definitely recommend getting a bigger tank if possible.
It won’t bite through the bag, they have sharp teeth but you are likely getting a 1 inch one which doesn’t have much of teeth. Not until about 3 inches will damage be possible, but even then it isn’t gonna bite through the bag. Only fish I had put a hole in a bag was a Texas cichlid, it was constantly pecking there, luckily the store I got it from wasn’t far from my house and it was a
Avoid live feeders, all they do is bring parasites and other harmful chemicals. Mine grew off of hikari carnivore food sticks, tetra min tropical flakes, and the occasional tankmate experiment.
Note that they love having plentiful hiding spots and dim light (bright light hurts their eyes).
Important question to consider: Why do you want a piranha?
Is it because it is a ravenous predator, because it is not. Piranhas are skittish, ambush predators that spend most of their time hiding. They are painfully skittish and only show that famous behavior during feedings. It takes a lot of work for them to be comfortable with people watching. Mine even played dead when I cleaned the tank it was so scared. They are omnivores and will go after plants (real or fake) as soon as they would other fish.
Red belly piranhas are my favorite freshwater fish because they are so misunderstood and beautiful. They have enough awareness of their surroundings to not be stupid, though they are not as smart as a cichlid. And yeah, the “most dangerous fish in the world” appeal, though false, is fun.
Thanos the RBP:
