Hey all....went to my LFS today looking for replacements for my oscars (old pair died suddenly...they were 14 though, they had a good life) I came across a trio in a tank. The owner said the smallest of the three was picking on another tiger oscar in the tank, but wasn't messing with the red oscar at all. I snapped them up. I have them in my 125 right now, but I think I may have a breeding pair. They don't leave eachother's sides. Is there a sure fire way to sex them?