Instructions
Observe the behavior of the fish. Male angelfish are aggressive and territorial. If a female is near a male, he will display his papilla, which is a tiny pink protrusion under his belly. If there are several males in your tank, remove the less dominant ones, as they have a tendency to eat the eggs, which slows breeding.
Observe the body structure of the fish. Males grow faster than females, are more robust and have a more rounded crown, which is the area just above their eyes.
Look for egg laying and breeding. The only way to know for certain which fish are females and which are males is if you observe the mating process. When the female is ready to produce eggs, she will have a distinct bulge in the area where her papilla is. Her papilla will also be much larger than a male's. When the female lays her eggs, her papilla will protrude and eggs will dispense in a straight line. The male will then swim over the laid eggs and touch them with his papilla.
How to Distinguish Between Male & Female Angel Fish
Angelfish are one of the most striking types of freshwater aquarium fish. Fish owners love adding these beautiful creatures to their aquariums because of their stunning appearance and active personalities. Like most varieties of fish, it can be difficult to determine the sex of an angelfish; however, by making a few different observations, you can learn how to distinguish between male and female angelfish. Once you know how to identify the sex of the fish, you will be able to assist in the breeding of angelfish.