well, bifasciatus means "two lines". If you see two horizontal black lines on the fish's side, that's a dead giveaway. Many Bifa's have a single horizontal black line, and then a black "area" above it, which is kinda like a second line, so that counts.
Google "bifasciatus", then click "images" and you'll see thousands of pics of Bifa's. Or, search for "rio chacamax bifasciatus"...