I have had them breed with OB Zebras, but they are no go so far with the Red Empress, but the Empress are breeding like crazy, but I haven't pulled babies because I was worried about crosses.. I was gonna switch the Empress out for my colony of Electric Yellows, and it sounds like that might be more successful. Given the OB Red Empress we have been seeing, I won't be putting them in with my zebras, but maybe they will get their own tank.