How to Tell a Girl Cichlid From a Boy Cichlid
Telling the gender of a fish is not that difficult once you learn how to spot certain attributes. In some species, "sexing" the fish is as easy as telling the gender in a bird – by size and color. One illustration of this "sexing" ease is the Beta. Beta males have large fins and usually are vibrant in colors, while the females have a smaller profile and dull colors. Cichlids are just as easy, although if the color pattern is not evident, then handling the fish will be required to tell what gender it is.
Search for photos on the Internet that illustrate the type of cichlid you have purchased if the species is dimorphic -- meaning the males and females have distinct coloring patterns. If you find that the species of cichlid you have chosen is not dimorphic, move to step 2.
Keep your hands wet and gently pick your cichlid up, turning it gently over so you can see its vent, or rectal opening. You will notice the hole and a bulge under it called a genital papilla. Females will have a large genital papilla, males will have a smaller one.
Check your cichlid for egg spots, which male mouth breeders will have on their anal fin, found just under the genital papilla.
Look at the size of your fish; males often are larger than the females.