The biological differences between species can vary greatly, but there are a few common traits to look for. Female cichlids, for example, tend to have rounded bodies and less pronounced vents, while males usually display more vibrant coloration and sometimes have a small hump on their heads.
[header] How to breed fish [title] Pick out a healthy adult fish of each sex. [step] In order to breed fish, your first step is to determine their biological sex. Unlike some other animals, this will be trickier than looking for differences in their genitalia.