Can Freshwater Angelfish (Scalare) Change Gender?

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Many people who own an aquarium have witnessed certain fish species to change their gender. Yes, there are species that can change from male to female and vice versa. But today we’ll talk about a certain breed and see if it can or cannot change its gender.

As you can tell from the title, we’ll talk about freshwater angelfish, or Scalar. After I answer the question, we’ll talk about the most common aspects of this subject:

  1. How to tell if your angelfish is male or female?
  2. The best age to differentiate males and females.
  3. Breeding freshwater angelfish: tips to accomplish it securely.
  4. “An example”

So, can Scalar change gender like many other fish species? The short answer is NO, they can’t. Freshwater angelfish are not known for changing gender like other breeds. Many people have a misconception in this regard, due to the fact that there are 2 types of angelfish: freshwater and saltwater angelfish.

Saltwater angelfish come in many different types. Some of them are capable to change their gender, but later in the article I will introduce you one specifically that is known for this trait.

Now that you know freshwater angelfish aren’t able to swap gender, you should know how to spot if one of them is a male or a female.

Sexing Freshwater Angelfish

Telling the difference between a male and a female angelfish is not an easy task. Even experienced fish keepers find it hard sometimes to spot the male and female. So, what can you do, to know which is which? I’ll give you some advice right below.

The simplest method for distinguishing freshwater angelfish, is by looking at their breeding tubes. Let me explain how:

The breeding tube is found on the bottom of each angelfish. What’s the difference between a male and a female tube? The male breeding tube is smaller and thinner compared to the one of females. It’s pointy and it looks like a pencil tip.

In the case of females, the breeding tube is wider and also blunt. This is because females will lay eggs, so they need a wider tube to be able to go through this process.

To tell the difference easier, just look at 2 fish at the same time. This way you’ll notice any differences quicker.

There are other signs that could tell you what gender your angelfish is. For instance, the look itself is quite helpful in this regard.

Male angelfish have certain differences: they have a more circular body than a female; on the forehead, they present a bump that females do not. The forehead area of males is more rounded before their eyes.

Males are usually fatter too. Their bodies look more robust and they also have forked ventral fins. If you watch them regularly a longer period of time, you’ll notice that males grow faster than females.

Females on the other hand don’t present a bump on their forehead. Their bodies are also smaller and slicker. The frontal fins are smoother.

Another method to tell the difference between freshwater angelfish, is to notice their behavior. This is easiest to do when they’re during breeding time.

Male angelfish will display a much more territorial behavior than females. During breeding, males will become more aggressive against other males, or even against other species. Differently, females only become more aggressive when they have to protect their fry. Also, they’re not territorial either.

Another usual behavior during breeding is this: the male fish will attempt to attract a mate by fanning out its fins and shaking them slightly to the other angelfish. The female will investigate the male, and if she finds him good for mating, will shake her fins in return.

The swimming style of males and females is also different. Males usually swim with their bodies horizontally from their mouth to tail. But females are holding their mouths a little higher compared to the center of the tail.

Best Age to Distinguish Male and Female Angelfish

For start, know that you won’t be able to distinguish the 2 genders when the fish are still too young. At that point, they look completely the same. So, when is it time to spot the differences?

The best period to distinguish the 2 genders, is when all the fish are matured. At this time, every aspect of their body is fully developed, so you can spot the differences easier.

Usually, a freshwater angelfish is fully developed when it’s ready to mate for the first time. This happens approximately when it is 6 or 7 months old. Until they don’t reach this period, you can’t tell for sure if one is a female or a male.

This is the best time, because their breeding tubes are also fully recognizable. Which means that you can tell way simpler which angelfish is male and which is female.

Of course, if you buy your angelfish when they’re already matured, you don’t have to wait at all to tell the difference among them.

Freshwater Angelfish Breeding Tips

Now, I’ll give you some tips about breeding freshwater angelfish.

  • To maximize the chance of breeding, let your angelfish pick their mates. This is much more efficient, because angelfish are very picky when it comes to mating. You can’t tell for sure if one will like the mate you prepare for it. So, put multiple ones together (males + females) and let them choose.
  • If you want a certain pair of angelfish to reproduce, then be patient. This is key, because if you don’t want random fish to mate, it might take a few tries to persuade them into mating each other. And even if you’re very patient, it might not work out in the end. Simply, this is how angelfish behave. So, don’t be bummed out about it!
  • When a pair is ready for mating, take the others out of the tank. Most of the time, angelfish like to be alone when breeding. So, keep the aquarium free of the other fish while the breeding happens. This is also important, because other fish breeds could hurt your angelfish in this period. Or at least, they won’t let them mate properly, and the breeding will never happen.
  • Freshwater angelfish very much like hiding places during breeding. Prepare multiple such sites, like small caves, to have an ideal environment ready for your fish. An efficient way to do this, is to prepare a separate tank from the beginning, that contains everything they need to mate and breed the way they want.
  • Be very careful about providing the best water conditions. Angelfish need a crystal clean water for breeding, so do water changes regularly and keep your filter at peek conditions in this period. Also, keep the temperature between 72- and 82-degrees Fahrenheit. Otherwise, the breeding won’t happen.
  • To ease your fish, you might need to paint the tank on the sides. This will make them feel more secure during this important period. To do it even better, you can cover up the top of the aquarium as well. Don’t worry because of the dark, because angelfish don’t mind it in this period.

Centropyge Ferrugata (Rusty Angelfish)

I mentioned above that I will also introduce you to a saltwater angelfish that changes gender when it has to. This is the Rusty Angelfish, or Centropyge Ferrugata. The Rusty is known to change from female to male, and the other way around as well.

Experiments were conducted with 2 pairs of Rusty Angelfish that have been cohabited. The smaller males that lost a contest and became subordinated, began to perform female specific mating rituals. In a certain period of time, their gender was completely changed to female.

Even the male specific coloration on the dorsal fin, changed to female specific coloration. When the gender swap was completed, they begun mating like they would normally do.

The experiments clearly show the capability of the Rusty Angelfish to switch genders when the situation requires that.


Let’s quickly recap what we talked about in today’s article:

At first, I answered your question, and said that freshwater angelfish aren’t able to swap genders at will. This thought is only a misconception that some people tend to talk about.

However, you could see that saltwater ones, at least some of them, have this ability. The Rusty is a good example in this regard. From the example above, it’s clearly seen that the Rusty is totally capable of full gender swap, quite quickly.

I also gave you some ideas on how you can spot the male and female in your angelfish community. There are multiple ways for doing this, but the most efficient is by examining the breeding tube of each specimen.

If you plan to breed freshwater angelfish, you know how to do it, thanks to the tips I listed above.

Don’t miss any of them, otherwise, you have only a tiny chance (if at all) to breed your angelfish successfully.

avatar I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.

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