They are not endangered because they don’t have a constant predator and because they hide between plants. Humans, also, don’t hunt piranhas. Maybe people go fishing piranhas but just for fun. Piranhas are not hunted because they are useless for the human. That’s why it is also difficult for the piranha to be endangered because they reproduce quickly and in large quantities.
I don't know, but I do know YOU will be endangered if you swim with them! ;)
No they are not endangered. Piranhas are not hunted because humans have no use for them.
No, these fish are not endanger because these are not listed in IUCN. For details, visit this link.