Ya I had this same confusion when I purchased my maingano, it's totally a labeling issue by LFS and there is technically no such thing as the EB johanni. Sounds like your store has maingano given they are so small and blue/black. I agree about buying a group of 8+, my initial group was 8 and my ratio turned out to be 6M:2F... males tend to be dark and females have lighter belly. Even then though I have had sub males looks like females. Good luck!