I had a few aimara from Brazil and seen many from VZ. They change and tend to look more alike as they get older. There is ZERO taxonomy differences between an aimara from brazil or Guyana or wherever. There might be some slight differences (scale color, eye color but that can change from river to river even in the same country. Alot of the juveniles look unique when younger then as they get older they do change to look more generic. To say that Sao Felix has 4 diamond triangles while the VZ has 3; i think is purely speculation and certainly not a constant. Whats this theory based on 5-6 Aimara from the Sao Felix which is all weve ever seen? Its not good science imo. Ive seen probably more aimara then most and perhaps have the largest picture database in the world of aimara pictures of anyone i know from all the locations. And I wouldnt say as an absolute that this aimara is from French Guyana and this one is from Amapa. For reason because they are so close together geographically. What i have observed is the ones from VZ tend to be a bit more robust in the head like a bull-dog and are bit darker in color. While the ones from Amapa tend to have that slant nose porsche look the head. While the colors tend to be a med to dark brown. Aimara are ambush predators so they can like most fish change there colors somewhat depending on there mood, stress etc. This is purely my opinion alone but the tempermeant of the VZ aimara. I believe are the most brazen and aggressive out compared the brazilian cousins. But again and i includ myself that all these hypothetical characteristics that are discussed on these forums are really only based on what 15 aimara? 30 aimara? When there is 100's of thousands of aimara in the wild. Maybe millions? Its not good probability and statistics if u know what i mean. Just know that any aimara that do make it out alive are lucky because so many die along the way. Why because they get so pissed off when caught in a in the gill net they die from stress en route. But one thing i will state for the record. And that is the Hoplias Aimara is the #1 meanest predatory freshwater fish in the world. Ive had em all to redline SH to P's and beyond. There is nothing like the Goliath Wolf Fish...