Can't tell until they get ready to spawn. The female gets full of eggs and gets huge. I think one of my four is a female because she got huge and then a few days later her stomach was small again. But theres no way eggs would survive in that tank. Everybody probably had cavier
LOL.. Carol you are too wild.. I'm picturing your fish breakfasting on caviar on toast, sipping Mimosas and gossiping about the neighbors in a Larson-'Far Side' cartoonish way, horn-rimmed glasses and all.. lol.