That's one big guy!
How long have you had him and is he a solo resident of the tank?
I had a female in with him with a divider. Odd thing, she wanted to breed, but he wanted to fight. After several close calls of roughing her up, he must have kept her from going back through the divider when I was at work and killed her. That was about 9 months ago. He has been by himself since (except for a few tetras and a pleco). He has gotten a lot thicker and fins have lengthened since being by himself.
I got him from COTA in March of 2016 as a 1" fish. So he should be a little over 5.5 years old.
I would like to get another Rio Chacamax bifasciatus female eventually and try again.
Also, I must apologize for my poor pictures.