if you don't know the collection point, then there's no way to tell for sure. mostly can make out the difference on rather it's a diamond variant or not. and it doesn't look like one.
could be just plain old peru rhom since they are the most common
a rhom is a rhom is a rhom. if you don't know the collection point you will never know where its from. as far as "diamond" or gold black or blue diamond its all whatever you want to call it. but the only real id you will ever know is serrasalmus rhombeus
Looks exactly like mine did about a year ago. Not saying it will turn out the same , but literally I thought that was a pic of my fish. I just put up a thread on what he looks like now.