A Fu would be great. Totally different body shape and utilizes a different part of the water column. I had a pair of fuzzies in a lion/scorp/waspfish tank that ran like perfection until they starting breeding and then everything started to go downhill. We noted they were suddenly picking on the Fu and the the whole dynamics changed. So, even if you really knew they were a pair, just know they are not the same fish when they are breeding.
We had bought the pair with the sex ID'd and we agreed with their label. It fit the criteria. Guess who we found to be holding eggs 2 years later.... the "male"! I'm putting together a sexing article and wanted to find the source of the information. I followed the breadcrumbs back to a solitary article that I was very disappointed in. If the ID isn't 100% accurate, what use is it really? They won't start fighting until they reach sexual maturity, so it's not something you'll even know at first and possibly for months to a year.
