How to Determine the Gender of Angelfish?

Disclosure: I may earn a commission when you purchase through my affiliate links. As an Amazon Associate I earn from qualifying purchases. – read more

As one of the most iconic species of freshwater aquariums, Angelfish are popular in home aquariums. It’s no accident they’re so loved – they’re aesthetically pleasing and relatively easy to keep.

Seeing their beauty and variety, it’s understandable that many aquarists will try to breed them. But here’s the catch – breeding Angelfish is difficult because it’s difficult to determine their sex.

Most times, I recommend people to just let Angelfish choose their own mates, since Angelfish prefer doing that anyway, and you simply can’t go wrong with this method.

Still, if you’re looking to breed certain Angelfish because of certain features, or you simply want to control their breeding process, you’ll need to be able to tell the difference between male and female angelfish.

Unfortunately, even experienced breeders have problems telling if an Angelfish is male or female, so it might be tricky to breed these fish based on physical traits alone.

This, however, does not mean that there aren’t some differences that can guide you in telling the gender of an Angelfish. If you know what you’re looking for, it’ll be easier to spot.

In this guide to determining the gender of Angelfish, I’m going to discuss the main differences between female and male Angelfish, so you’ll know what to look for when trying to breed them.

Sexing Angelfish

If I were to give a general description of Angelfish, I’d say that their most noticeable characteristics are their heightened, flattened-on-the-sides body and large flowy fins.

One look at their unusually-shaped bodies and you can tell right away – these fish are not small tank species. They come in different colors and their silvery bodies feature black vertical stripes.

They’re semi-aggressive fish that do well in large community tank if you choose suitable tank mates for them.

They’re bound to become aggressive in small tanks or overstocked tanks and during breeding time or when caring for their juveniles.

Males are usually the ones displaying signs of aggression and territorial behavior.

Many beginner aquarists may not be interested in what gender their fish are, until it becomes important for them to breed their fish.

Before I get into the specific characteristics of each Angelfish gender, a word of advice: Don’t bother trying to determine the gender of juvenile Angelfish, it’s an impossible task.

Angelfish reach reproductive maturity only at around 6 or 7 months of age, when they begin forming pairs.

Once these fish become reproductive, differences start to appear, and a trained eye will be able to distinguish between a female and male Angelfish.

Differences Based on Breeding Tube

You’ll probably find all sorts of tips and tricks on the web on sexing Angelfish, but the most straightforward way to tell which is which is to look at their breeding tube.

Based on their breeding tube and general physical traits, here are some clues to spot the difference between the two genders:


Male and Female Angelfish – Source:

Male Angelfish

  • Male Angelfish generally have a larger, more circular body than the female;
  • An enlarged bump on the head is also a sign of a male Angelfish;
  • Forehead area right before their eyes is more rounded;
  • Male breeding tube is thinner and pointy much like a pencil tip;
  • More fatty and robust bodies;
  • Forked ventral fins;
  • Male Angelfish generally grow faster than female ones.

Female Angelfish

  • Female Angelfish don’t have any bumps on their foreheads and feature a more of a ski slope like shape;
  • Their bodies are smaller;
  • Frontal fins are smoother;
  • Angular belly line;
  • Breeding tube is wider and blunt.

Even with these differences, your determination of gender may be a hit or miss. Some other aspects that you can look for include their behavior, especially during the spawning period.

Differences Based on Behavior

Perhaps the most striking difference between the behavior of female and male Angelfish is the territorial behavior that male Angelfish display, which is more pronounced during breeding time.

Angelfish can become aggressive or territorial against other male Angelfish or males of other species. Female Angelfish usually only become territorial or potentially aggressive when protecting her juveniles.

Because of their potentially aggressive behavior, you should be careful in choosing tankmates for your Angelfish. You should avoid aggressive species, or species that nip at the fins of other fish.

Good tankmates for Angelfish include mollies, corydoras, platies, bristlenose plecos, kuhli loaches, and swordtails.

During breeding time, in attempt to attract a mate, the male Angelfish will fan out their fins and slightly shake them. The female Angelfish will check out the male and shake her fins in acceptance.

Differences can also be found in the way these fish swim – males usually hold their bodies horizontally from mouth to tail, while females usually hold their mouths slightly above the center of their tails.

Breeding Angelfish

If you’re adamant to pick and match your Angelfish according to certain physical traits, be prepared that you may need a few tries until you get it right.

And even if you get it right, Angelfish may not always be happy with the mate you’ve chosen for them. If you let your Angelfish figure out which mate they want to pick, you maximize your chances of breeding them.

Sometimes it’s impossible to tell the difference until you see them laying eggs and guarding the eggs and juveniles together.

If you pay attention to your Angelfish, you’ll soon notice if a pair is getting ready for spawning. They usually stick together, scare away other fish and they’re preparing the spawning site for laying eggs.

The fish usually pick a site that they’ll take turns in cleaning. As the eggs of the female Angelfish reach maturity, her abdomen swells, and she develops a short spawning tube.

The female can lay several hundreds of eggs. She lays them row by row, then the male fertilizes them. They take turns in fanning the eggs and keeping them clean, removing the ones that haven’t been fertilized or that are dirty.

In a few days, the eggs hatch and larvae remain stuck to the surface through a sticky thread. It takes a week or so for larvae to turn into juveniles that can swim and search for food.

All this time, Angelfish continue to care for their fry until they become independent and strong enough to make it on their own.

This is how things unfold in ideal conditions, however, there may be situations when due to stress Angelfish may eat their eggs and juveniles.

Therefore, aquarists that are breeding Angelfish for commercial purposes, will hatch eggs artificially, and there are various ways that they can do so, however, in each case aeration and very clean water are indispensable.

Optimal Tank Conditions for Breeding Angelfish

Angelfish are more inclined to spawn when they’re in a tank by themselves, therefore, avoid keeping them with other Angelfish or in a community tank.

You also need to keep the fish in good condition by feeding them a healthy and diverse diet that meets their nutritional requirements.

Water cleanliness is another must-do during this period. Therefore, keep doing water changes religiously and provide a well-planted tank with lots of shade and hiding places.

In terms of water chemistry, sometimes – if your Angelfish aren’t breeding – you’ll need to make adjustments like:

  • Using deionized or reverse osmosis water if your water is extremely hard or extremely alkaline;
  • Avoid extreme temperatures, keep temperature in the 72° and 82° F range;
  • Painting the outside of bare-bottomed tanks with a matte color to make the Angelfish pair feel more at ease;
  • Some couples will require a covered tank, or a tank painted on the sides as well;
  • Other couples will require a dither fish;
  • Adding active sponge filters to the tank to minimize any toxin levels that may upset Angelfish.

Some Angelfish pairs may be this picky, making the aquarist jump through several hoops until they get all conditions right for breeding.

However, you may also be very lucking and land a pair that isn’t fussy at all. The key is to experiment with various things and see how your Angelfish respond to these changes.

You must also understand that some pairs just don’t work or aren’t compatible and you may have to switch pairs until you find a suitable combination.

Regardless of what anyone will tell you about sexing Angelfish, know that there isn’t a proven and reliable method to sex angelfish unless their breeding tubes are lowered, and they have been examined with a magnifying glass by someone experienced.

Do Male and Female Angelfish Fight?

Usually only male angelfish fish for territory and for females. It can happen, that the male will chase the female angelfish before laying the eggs, but this can’t be considered fight. It is normal and is part of their breeding ritual.

If your angelfish pair has been laying eggs in a community tank, where other angelfish are present, the male can fight other female angelfish, to keep them away from the eggs. This is more just chasing them away, and not real fight.

Can Male Angelfish Kill Female Angelfish?

In an overcrowded tank, male angelfish will fight for territory and can kill each other. It is uncommon for male angelfish to kill a female angelfish, but it can happen.

Final Thoughts

Knowing the gender of your Angelfish can have implications in successfully breeding them or finding suitable tank mates for them.

Unfortunately, even if you know some of the things that can help you tell female and male Angelfish apart, due to extensive breeding, these differences may not be as striking or clearly visible.

Therefore, since there isn’t a 100% efficiency method to tell the gender of an Angelfish, it will take some practice spotting the differences or finding a pair that’s willing to breed.

Author Image Fabian
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.
Questions and Answers

    For angelfish it doesn’t really matter what substrate you use. Use a substrate that is more convenient for you. Gravel is much easier to clean and vacuum, while sand looks more natural in my opinion. It is up to you which substrate you use.

Leave a Comment

Your email address will not be published. Required fields are marked *