Can Angelfish Change Gender?

Freshwater angelfish cannot change gender. The gender of freshwater angelfish is already established at birth. Male and female angelfish display subtle but distinctive differences in features and traits.

Determining the gender of young freshwater angelfish is no easy task. The physical differences between male and female angelfish are very subtle. However, it is possible to correctly determine the sex of mature fish when their features are more prominent.

Freshwater Angelfish Cannot Change Gender

There are two species of angelfish, marine, and seawater. The more exotic marine type angelfish can change gender if required, but freshwater angelfish cannot change their gender.

A female marine angelfish will transition to male in cases where the male in the group dies. The largest and more mature female will become male to protect the group and ensure offspring.

Two Striped Angelfish Facing Each Other

How To Determine The Gender Of Angelfish

An angelfish’s gender is determined by examining their body shapes, watching mating groups, and observing their spawning tubes. Remember that these differences will become more apparent as the fish mature.

1. Examine The Body Of Angelfish To Determine Gender

There are distinct differences between the bodies of male and female angelfish. Therefore, one can use these differences to determine the gender of an angelfish.

It is always easier to identify the differences between genders when examining and comparing the features of two or more angelfish at a time. Doing so will help you spot differences in their appearances easier.

Male angelfish are physically bigger than females. The male’s heads have a more profound profile, resembling a crown, and their mouths pout upward. They appear flatter than their female counterparts.

Female angelfish are slightly smaller, and their bodies appear rounder than the males. The female profiles appear rounder, and their mouths, head, and body follow the rounded shape. Due to their rounder profile, the female’s dorsal fins are more in line with their eyes than those of males.

Observe the fish as it swims toward you. You will notice that the bellies of the female fish are wider than the bellies of the males. The males appear almost flat when swimming towards you.

2. Observe Mating Groups To Determine Angelfish Gender

It is advisable to purchase at least six angelfish, especially if you want to breed them. Consider mixing small juveniles and larger fish in the same tank. Ensure enough space for all the fish since they will mature and pick mates from six months of age.

The way the fish pair off should be a good indication of how many males and females you have. Fish of the same gender often pair off to spawn but to no avail.

Mating pairs become territorial and protective of their mates, and you must separate them from the rest.

When studying the mating pairs, it is easier to identify the differences between the genders. The subtle yet significant differences will become more apparent. Look for differences in physical shape and form, profiles, and size.

Female angelfish lay their eggs on plants or any suitable surface within the tank. At the same time, the males follow closely to fertilize the eggs.

3. Examine Spawning Tubes Of Angelfish To Determine Gender

Male and female angelfish have external spawning tubes that allow the female to lay eggs and the male to fertilize the eggs.

The shape and size of the spawning tubes indicate the gender of the angelfish. The spawning tubes are situated closely behind the feeler fins.

The spawning tube of female angelfish resembles a triangle with rounded corners and a cylindrical shape.

Female angelfish lay eggs via the spawning tube. Male spawn tubes resemble a sharpened pencil, narrow and pointy. Males use the spawn tube to release the sperm that fertilizes the eggs.

How To Examine Angelfish Spawn Tubes To Determine Gender

Examining the spawn tubes of angelfish up close is a sure way of determining gender and needs to be performed with great care.

According to the spawn tubes, wait for the fish to mature before attempting to sex them. The more mature the fish, the easier you will see the differences.

You can temporarily move the fish to a smaller tank for closer observation or catch them in a net.

Then, carefully take them in your hand and turn them over with great care not to hurt them, and have a quick look at the underbelly to determine the sex.

Remember that handling the angelfish will cause them stress, which is never good for any animal. Therefore, always consider all the consequences before physically handling your fish to determine the gender.

It will be good to remember that the rate at which angelfish mature may vary even if they are kept in optimum conditions, healthy and happy. So always ensure that the tank you keep the angelfish in is large enough to house them and their tank mates comfortably.

Maturing Of Freshwater Angelfish

It is indeed possible, albeit challenging, to determine the gender of freshwater angelfish, especially if you wish to breed them. However, determining their gender before six months will be futile as the fish have not matured yet, and physical differences will not fully present themselves.

Angelfish start as eggs, and the small angelfish are called fry when the eggs hatch. Fry hatch as male or female without the ability to change gender.

Happy, healthy angelfish will start maturing at around six to seven months. At this age, the angelfish will be the size of a silver dollar coin, and you will notice them starting to pair off. In addition, the differences between gender will now start to become more noticeable.

In ideal conditions, angelfish will reach maturity between eight and twelve months. Of course, even at this age, you will need a trained eye to determine the gender correctly, but if you know what to look out for, you should get the hang of it in no time.

Differences In Male And Female Angelfish Personalities

Contrary to their name, male angelfish are incredibly territorial and aggressive towards other male angelfish or even males of other species, especially during spawning season. They pick fights and chase other male fish around the tank to protect their mate and territory.

Female angelfish are more relaxed and not so territorial. It is good practice to move a mating pair to a separate tank to spawn and raise their fry. Removing them from the main tank protects the tank mates from the wrath of the not-so-angelic male and protects the eggs from becoming a meal.


Keeping and breeding angelfish proves profitable and rewarding. Knowing how to determine the gender of your angelfish will further add to your joy and amazement. Happy gendering!